This document summarizes a study that examined the effects of calcium soaps of fatty acids (CSFA) on postpartum reproductive activity in beef cows and growth of calves. The study found that incorporating 125 g/d of CSFA in a range supplement:
1) Increased weights of calves at various ages up to weaning compared to a control diet.
2) Resulted in higher body weights and body condition scores in cows in early postpartum periods compared to the control diet.
3) Led to a greater percentage of cows cycling and pregnant during the breeding season compared to the control diet.
Dr. Clay Lents - Nutritional Strategies for Managing Growth and Body Composit...John Blue
Nutritional Strategies for Managing Growth and Body Composition in Gilts"" - Dr. Clay Lents, from the 2018 Allen D. Leman Swine Conference, September 15-18, 2018, St. Paul, Minnesota, USA.
More presentations at http://www.swinecast.com/2018-leman-swine-conference-material
Dr. Clay Lents - Nutritional Strategies for Managing Growth and Body Composit...John Blue
Nutritional Strategies for Managing Growth and Body Composition in Gilts"" - Dr. Clay Lents, from the 2018 Allen D. Leman Swine Conference, September 15-18, 2018, St. Paul, Minnesota, USA.
More presentations at http://www.swinecast.com/2018-leman-swine-conference-material
New Tools to Manage Reproduction ProgramsDAIReXNET
Dr. Paul Fricke presented this information as a webinar for DAIReXNET on Monday, April 22, 2013. For more information, please see our archived webinars page at www.extension.org/pages/15830/archived-dairy-cattle-webinars.
Uterine Health and Potential Connection with Genetic VariationDAIReXNET
Dr. Galvão joins us to discuss uterine diseases, their effects on fertility, and a possible genetic connection. Learn about his research methods, the detrimental effects of metritis on fertility, and which genes could be related to uterine diseases.
To view the full presentation, visit https://www.youtube.com/watch?v=jZvuFi_qKPQ
Dr. Joe Cassady - Effects of preweaning factors on sow lifetime productivityJohn Blue
Effects of preweaning factors on sow lifetime productivity - Dr. Joe Cassady, from the 2012 Allen D. Leman Swine Conference, September 15-18, St. Paul, Minnesota, USA.
More presentations at http://www.swinecast.com/2012-leman-swine-conference-material
Validation of the dry matter intake formula of Spartan 3 Ration Evaluator / B...nacaa
Robb, G.W. * 1, VandeHaar, M.J. 2, Bucholtz, H.F.2, Michigan State University
1 Senior Extension Educator, Michigan State University, 12220 Fillmore St. Suite 122, West Olive, MI 494602 Department of Animal Science, Michigan State University, 2265J Anthony Hall, E. Lansing, MI 48824
An Overview of Genomic Selection and FertilityDAIReXNET
In this webinar, released July 18, 2016, Dr. Hansen joined us to discuss genomic selection as it relates to fertility traits. Learn about single nucleotide polymorphisms (SNPs), the challenges in selecting for reproductive traits, and some of the current work in overcoming those challenges.
New Tools to Manage Reproduction ProgramsDAIReXNET
Dr. Paul Fricke presented this information as a webinar for DAIReXNET on Monday, April 22, 2013. For more information, please see our archived webinars page at www.extension.org/pages/15830/archived-dairy-cattle-webinars.
Uterine Health and Potential Connection with Genetic VariationDAIReXNET
Dr. Galvão joins us to discuss uterine diseases, their effects on fertility, and a possible genetic connection. Learn about his research methods, the detrimental effects of metritis on fertility, and which genes could be related to uterine diseases.
To view the full presentation, visit https://www.youtube.com/watch?v=jZvuFi_qKPQ
Dr. Joe Cassady - Effects of preweaning factors on sow lifetime productivityJohn Blue
Effects of preweaning factors on sow lifetime productivity - Dr. Joe Cassady, from the 2012 Allen D. Leman Swine Conference, September 15-18, St. Paul, Minnesota, USA.
More presentations at http://www.swinecast.com/2012-leman-swine-conference-material
Validation of the dry matter intake formula of Spartan 3 Ration Evaluator / B...nacaa
Robb, G.W. * 1, VandeHaar, M.J. 2, Bucholtz, H.F.2, Michigan State University
1 Senior Extension Educator, Michigan State University, 12220 Fillmore St. Suite 122, West Olive, MI 494602 Department of Animal Science, Michigan State University, 2265J Anthony Hall, E. Lansing, MI 48824
An Overview of Genomic Selection and FertilityDAIReXNET
In this webinar, released July 18, 2016, Dr. Hansen joined us to discuss genomic selection as it relates to fertility traits. Learn about single nucleotide polymorphisms (SNPs), the challenges in selecting for reproductive traits, and some of the current work in overcoming those challenges.
Use of Silage Acid Devil Fish (Pterygoplichthys spp.) as Protein Supplement i...criollito
Animal nutrition is one of the most important limiting factors in animal production, especially in ruminants, providing
proteins being the main constraint, due to the limited availability and high cost of protein sources (oilseed meals). Currently in the dam
“El Infiernillo” in Michoacán México, has a large population of devil fish (Pterygoplichthys spp.), which is an economic and ecological
problem, because it is not consumed by humans and causes pollution to be discarded directly into the environment. For that reason the
objective of this study was to evaluate the use of silage acid devil fish (SADF) in fattening beef cattle as a protein supplement. SADF is
defined as a product semi-liquid or pasty mixed with formic acid, which leads to a decrease in pH to near 4.0. Used 18 young bulls (Bos
taurus × Bos indicus) for 60 days with a starting weight of 278.9 ± 51.2 kg, housed in individual pens with food and water ad libitum
were randomly assigned to three treatments with different levels of inclusion SADF (0%, 12% and 18%). They were weighed to the
beginning of the experiment and later every 30 days, previous fasting of 24 hours. To determine the food consumption, weigh every day
the offered food and the surplus. There were no significant differences (P < 0.05) among treatments with different levels of inclusion of
SADF with respect to daily weight gain, with values of 952 ± 324, 927 ± 322 and 854 ± 307 g/day, respectively. The dry matter intake
(DMI) was 8.9, 9.3 and 7.7 kg/day to 0%, 12% and 18% of SADF, respectively. In the same values for feed conversion were 9.34, 10.03
and 9.01 kg DMI/kg of weigh live, and carcass yield of 60.6%, 60.3% and 58.5%, respectively. It is concluded that fish silage acid devil
is an excellent alternative in feeding beef cattle as a protein supplement.
AJUSTE DE MODELOS DE REGRESIÓN ALEATORIA EN EVALUACIONES GENÉTICAS DE BOVINOS...criollito
La curva de crecimiento del ganado tiene una forma sigmoidea
que puede ser ajustada con modelos de regresión
aleatoria. El objetivo de este estudio fue ajustar un modelo
de regresión aleatoria con base en polinomios de Legendre,
y estimar componentes de varianza y parámetros genéticos,
para datos de crecimiento en bovinos Tropicarne. Se analizó
la información de 12 890 pesadas mensuales, del nacimiento
a los 24 meses de edad de 1787 becerros. El pedigrí incluyó
2504 animales. Se compararon 27 modelos lineales, cuadráticos
y cúbicos para ajuste de los efectos genéticos (EGA) y
de ambiente permanente (APA) del animal, con tres estructuras
en las varianzas de residuales (homogénea, y heterogénea
de seis y doce clases). Una vez seleccionado el modelo
con los efectos del animal, se analizaron otros nueve modelos
para determinar la posible adición de los efectos maternos,
genéticos (EGM) y de ambiente permanente (APM).
Los análisis se realizaron con el programa DFREML. Los
modelos se compararon con base en: proporción de verosimilitudes,
criterio de información de Akaike y criterio de
información bayesiana. El modelo con mejor ajuste incluyó
los EGA de orden cuadrático y los efectos de APA, EGM
y APM de orden cúbico, con varianza residual heterogénea
en doce clases. Las varianzas fenotípicas de EGA y de EGM
presentaron tendencia positiva con la edad; sin embargo,
la varianza residual presentó un comportamiento cuadrático
en los primeros ocho meses del crecimiento y luego se
mantuvo constante. La heredabilidad directa promedio fue
0.079, con valores de 0.006 a 0.06 hasta los siete meses; y
desde los ocho meses fue constante (alrededor de 0.11). La
heredabilidad materna promedio fue 0.084, con valores de 0.02 a 0.06 hasta los siete meses y de 0.07 a 0.16 desde de
los ocho meses de edad. El modelo de regresión aleatoria fue
el mejor desde los nueve meses de edad, pero subestimó los
parámetros genéticos para edades menores.
Dr. Dean Boyd - Improving Finish Pig Viability By Using XylanaseJohn Blue
Improving Finish Pig Viability By Using Xylanase - Dr. Dean Boyd, The Hanor Company, from the 2015 Allen D. Leman Swine Conference, September 19-22, 2015, St. Paul, Minnesota, USA.
More presentations at http://www.swinecast.com/2015-leman-swine-conference-material
Effect of feed at different times prior to exercise and chelated chromium sup...Lilian De Rezende Jordão
Nutritional management studies to improve the performance of Mangalarga Marchador (MM) horses during the
marcha test are limited. This study was designed to test the hypothesis that chelated trivalent chromium (CR)
feed supplementation may reduce the suitability of the length of the interval between concentrate feeding and
the marcha test among MM horses. A total of 12 healthy mares (4.25 ^ 0.62 years) were randomly assigned
to one of six dietary treatments (0 or 10 mg Cr by concentrate, fed 0.5, 2 or 4 h before exercise), according to
a completely randomized design, with a split-plot arrangement. The diet was Cynodon pasture and concentrate
(50:50 ratio). The first 29 days of the trial were for diet, Cr and exercise adaptation; during the next 15 days,
horses were submitted to three 50-min field marcha tests, once a week. Heart rate (HR) was measured before,
during and until 25 min after the exercise. Respiratory rate and rectal temperature were measured; blood samples
were collected before, at the end and 25 min after the test. There was no effect of Cr by concentrate feeding strategy
on any physiological variables (P . 0.05). Supplementation of Cr increased glycaemia before and soon after
the second marcha test (P , 0.01). In addition, Cr reduced HR during the second marcha test and decreased
the time to first post-exercise HR recovery (P , 0.05). Insulinaemia was greater when the concentrate was
provided 2 h prior to the test (P , 0.05). Concentrate provided 0.5 and 2 h before the test reduced plasma triacylglycerol
in the first and second tests, respectively. The interval between concentrate feeding and marcha tests
should not be decreased in horses supplemented with Cr. Horses should be fed more than 2 h before that test. Cr
supplementation during training may improve the cardiac performance of MM mares during the marcha test.
A study was carried out to evaluate the nutritive value and enzyme supplementation of different sources of energy in broiler diets on the growth performance and heamatological parameters of broiler chickens supplemented with Mazigrain® enzyme within the treated groups. Five isonitrogenous and isocaloric diets less (23.17 % CP; 2831 Kcal/ME and 21.73 % CP; 2929 Kcal/ME) for the broiler starter (0 - a month) and finisher phases (5–8 months) respectively were formulated. Diet 1(maize based diet) served in as the control while diets 2, 3, 4 and 5 were supplemented with sorghum, pearl millet, cassava and sweet potatoes based diets separately. A sum of 225 day-old NAPRI X broiler chicks were haphazardly distributed to the five treatments. Every treatment comprised of 45 broilers with three repeats of fifteen birds each in a Completely Randomized Design (CRD). The general linear model protocol of S.A.S. 9.0. was used to analyze the collected data. Among the dietary groups significant changes (P<0.05) was found utilizing a Tukey test. Enzyme along with various energy sources have noteworthy (P<0.05) changes on every one of the parameters (final weight, daily weight gain, feed conversion ratio, water intake, water to feed ratio and feed cost per kilogram weight gain) except for death rate at the starter phase. Broilers that had sorghum based diet had the best performance at starter stage (final weight; 627 g, weight gain; 576.85 g, feed cost/kg gain; ^ 187.95 k). At the finisher stage, sorghum supplemented with enzyme had the best feed conversion ratio (1.96) and feed cost/kg gain; ^ 171.15 k. The optimal performance characteristics were recorded for sorghum based diets. Feed cost / kg gain was the cheapest on birds fed sorghum based diet with enzyme supplementation which was comparable with those fed the maize based diet. However, the use of enzyme enhanced the performance of birds at both the starter and finisher phases.
A study was carried out to evaluate the nutritive value and enzyme
supplementation of different sources of energy in broiler diets on the growth
performance and heamatological parameters of broiler chickens supplemented with
Mazigrain® enzyme within the treated groups. Five isonitrogenous and isocaloric diets
less (23.17 % CP; 2831 Kcal/ME and 21.73 % CP; 2929 Kcal/ME) for the broiler starter
(0 - a month) and finisher phases (5–8 months) respectively were formulated. Diet 1
(maize based diet) served in as the control while diets 2, 3, 4 and 5 were
supplemented with sorghum, pearl millet, cassava and sweet potatoes based diets
separately. A sum of 225 day-old NAPRI X broiler chicks were haphazardly distributed
to the five treatments. Every treatment comprised of 45 broilers with three repeats of
fifteen birds each in a Completely Randomized Design (CRD). The general linear model
protocol of S.A.S. 9.0. was used to analyze the collected data. Among the dietary
groups significant changes (P<0.05) was found utilizing a Tukey test. Enzyme along
with various energy sources have noteworthy (P<0.05) changes on every one of the
parameters (final weight, daily weight gain, feed conversion ratio, water intake, water
to feed ratio and feed cost per kilogram weight gain) except for death rate at the
starter phase. Broilers that had sorghum based diet had the best performance at
starter stage (final weight; 627 g, weight gain; 576.85 g, feed cost/kg gain; ^ 187.95 k).
At the finisher stage, sorghum supplemented with enzyme had the best feed
conversion ratio (1.96) and feed cost/kg gain; ^ 171.15 k. The optimal performance
characteristics were recorded for sorghum based diets. Feed cost / kg gain was the
cheapest on birds fed sorghum based diet with enzyme supplementation which was
comparable with those fed the maize based diet. However, the use of enzyme
enhanced the performance of birds at both the starter and finisher phases.
The objective of this study was to evaluate the effect of the systematic use of a single amount of the prostaglandin F2α after one month of calving on the renewal of sexual activity of beef at Chad. (Sixty five (65) cows of local breeds from N'Djamena urban area were selected and divided Into two groups: Forty-three (43) cows were treated with Prostaglandin F2α, one month after calving and 22 cows as witnesses. More than half (60.46%) of the cows answered the treatment and 39.54% did not react. The answer varied with the parity (68%) for the first half of the cows against 32% for the multiparous but the body weight at calving did not-have an effect. Only, the acceptance of overlapping was Retained for the detection of return in heat, which took place on an average of 2.36 ± 0.14 days after treatment. The treatment made it feasible to-have-one year interval between calving (first heat of 32.36 ± 0.14 days.) Heat thus obtained, can be used as reference to the stockbreeders to program the reproduction of their herd in order to have one year interval calving-calving closed. This test sample gave better Indication in first half of the cows while waiting for confirming it in the station.
LOS ÁCIDOS GRASOS DE LA DIETA AFECTAN LA FISIOLOGÍA REPRODUCTIVA EN LA HEMBRA...criollito
Reproduction is the basis of bovine meat and milk production: As a direct result of reproduction, the cycles of calf and milk production are renewed. However, there are many limiting steps in this process as: low pregnancy rates and long open days that result in increasing parturition intervals. Reproductive efficiency in dairy and beef cattle is multifactorial. Nutrition is one of the most important factors affecting this efficiency, and some results have shown that feeding diverse sources of lipids and specifically, fatty acids (FA) can result in a better reproductive efficiency. As a nutrition strategy to improve reproductive efficiency, FA of the omega 3 (n-3) and omega 6 (n-6) families have been studied, and it has been shown that these FA can control follicular development, production of progesterone in the corpus luteum, and secretion of PGF2α from the endometrium, increasing embryonic survival and pregnancy rates. The purpose of this revision is to analyze the possible mechanisms by which FA in the diet improve reproductive efficiency of cows, with especial emphasis on FA n-3 and n-6.
Parámetros y tendencias genéticas del peso al destete y a los 18 meses de eda...criollito
El objetivo fue estimar la heredabilidad directa y materna del peso al destete a los 7 meses (PD), y peso final a los 18 meses
(PF) y sus valores y tendencias genéticas en bovinos Cebú bermejo de Cuba. Se utilizó un modelo animal bicarácter en 5,120
registros de PD y 1,134 de PF. Los animales nacieron entre 1982 y 2008 en tres hatos. El modelo para el PD incluyó los efectos
del grupo de contemporáneas (hato–año–estación de nacimiento-sexo, edad al destete como covariable lineal y edad de la madre
como lineal y cuadrática), efecto aleatorio del animal, aleatorio materno, del ambiente permanente y el error. El modelo para
PF incluyó el grupo de contemporáneas (hato-año-estación de nacimiento), edad al peso final como covariable lineal, efecto
aleatorio del animal, efecto del ambiente permanente y el error. Las tendencias genéticas se estimaron mediante regresión lineal
del valor genético aditivo promedio sobre los años de nacimiento, de 1982 a 2007. La heredabilidad del PD fue 0.11±0.04 y
0.03±0.02 (efectos directos y maternos, respectivamente) con una correlación genética de -0.15±0.24 entre dichos efectos. La
heredabilidad del PF fue 0.28±0.10. Las tendencias genéticas resultaron positivas y significativas para el efecto directo de PD
(0.102 kg) y PF (0.244 kg). Se concluye que la heredabilidad de los efectos directos y maternos del PD fueron bajas, y el PF
tiene un índice de herencia moderado que puede favorecer la respuesta a la selección en los programas de mejoramiento
genético.
PALABRAS CLAVE: Heredabilidad, Bovinos en trópico, Valor genético, Peso final.
ECUACIONES DE PREDICCIÓN PARA ESTIMAR EL POTENCIAL PRODUCTIVO DE Ferocactus spp.criollito
El componente florístico en Baja California Sur, México, es
amplio e importante en las actividades de sus habitantes. Algunas
plantas han sido utilizadas en la alimentación y la ornamentación.
Esto ha llevado a que las biznagas (Ferocactus
spp.) actualmente estén consideradas en peligro de extinción.
El objetivo del presente trabajo fue evaluar a Ferocactus spp.
para determinar su potencial en la producción de semillas.
Se eligieron 25 plantas de diferentes alturas y diámetros, con
~5 años de haber sido trasplantadas. Se midieron la altura
y el diámetro. Se contaron y colectaron los frutos los cuales
se pesaron en verde (PVF) y al secarse (PSF), se contaron
las semillas de cada fruto (SPF) y el total de semillas por
planta (TSPP). El diámetro se correlacionó significativamente
(P<0><0><0><0,0001). Se concluye que el diámetro de
las plantas puede utilizarse como predictor en las ecuaciones
establecidas para el peso verde del fruto, peso seco del fruto y
el número de semillas por fruto. La altura de la planta puede
usarse para predecir el total de semillas por planta.
COMPONENTES DE (CO)VARIANZA DEL CRECIMIENTO POSDESTETE EN VAQUILLAS SANTA GER...criollito
La capacidad de crecimiento, uno de los factores más importantes
en bovinos productores de carne, está determinada por
el crecimiento pre y post destete, por lo que ambas etapas son
relevantes en los procesos de selección de reproductores. La
estimación precisa de los componentes de (co)varianza y parámetros
genéticos durante estos periodos mejora la respuesta
en esquemas de selección. Con este objetivo se estimaron
componentes de (co)varianza y parámetros genéticos del crecimiento
desde el destete hasta los 900 d de edad en vaquillas
Santa Gertrudis, mediante un modelo de regresión aleatoria
utilizando polinomios de Legendre para los efectos aditivo,
materno y de ambiente permanente. Se usaron 5709 pesajes
de 1903 vaquillas y se registraron sus pesos al destete, al año
de edad y al inicio de la etapa reproductiva. El análisis de los
resultados indicó un aumento de las varianzas aditiva y de
ambiente permanente con la edad, mientras que la varianza
debida a efectos maternos disminuyó. La tendencia de la heredabilidad
para los efectos directos fue decreciente del destete
(0.08) hasta los 280 d de edad (0.04); de ahí y hasta los
900 d aumentó (0.20). Los efectos del ambiente permanente
fueron opuestos a la heredabilidad para los efectos directos.
La heredabilidad para los efectos maternos decreció de 0.10
(al destete) hasta 0 (a los 900 d). Las correlaciones genéticas
fueron negativas entre los pesajes más distantes, pero altas
y positivas entre pesajes consecutivos, con valores mayores a
0.85 desde los 400 d, por lo que la selección para peso corporal
a edades posteriores será más efectiva.
COMPONENTES DE (CO)VARIANZA PARA PESO AL DESTETE DE GANADO CEBÚ BERMEJO CUBANOcriollito
Con el objetivo de estimar los componentes de (co)varianza del peso al destete en el ganado Cebú bermejo cubano se tomó una muestra de 5120 registros de animales hembras y machos que nacieron entre los años 1988 y 2007 en tres hatos ubicados en las provincias de Cienfuegos, Camagüey y Granma. Se utilizaron seis modelos estadísticos diferentes que tenían en común el efecto fijo de grupo de contemporáneo (año-hato-época-sexo) y las covariables edad al destete lineal, edad de la madre al parto lineal y cuadrático. El modelo 1 sólo incluyó el efecto aleatorio del animal, el modelo 2 incluyó además el efecto aleatorio del ambiente permanente, el modelo 3 fue igual que el 1 pero incluyó además el efecto aleatorio genético materno, sin considerar la existencia de covarianza entre los efectos aditivos y maternos, el modelo 4 fue igual que el 3 pero consideró la existencia de covarianza entre efectos aditivos y maternos, los modelos 5 y 6 fueron iguales a los modelos 3 y 4, respectivamente, pero adicionando el efecto aleatorio del ambiente permanente. El peso al destete promedio fue de 159.7 kg, con una desviación estándar de 26.7 kg. Se utilizaron tres criterios para comparar los modelos; el logaritmo de la verosimilitud (log L), el criterio informativo de Akaike (AIC) y el criterio informativo de Bayes (BIC). El modelo 1 fue el de peor ajuste considerando los tres criterios. Teniendo en cuenta el criterio log L los modelos 5 y 6 no difieren significativamente entre ellos y resultaron los mejores con relación al resto. Los criterios AIC y BIC señalan al modelo 5 como el mejor. La heredabilidad para el efecto aditivo directo (0.32) en el modelo1 fue superior a la estimada para con el resto de los modelos (0.02-0.06), lo que indica que ignorar los efectos maternales produjo una sobreestimación de este parámetro. Las heredabilidades estimadas para los efectos maternos en los modelos de mejor ajuste alcanzaron valores de 0.06 (modelo 5) y 0.04 (modelo 6). Los efectos del ambiente permanente determinaron entre un 10.9% (modelo 6) y 15.4% (modelo 3) de la variabilidad total. La correlación genética entre los efectos directos y maternos alcanzó valores de 0.53 y 0.61 para los modelos 4 y 6, respectivamente. Los resultados indican que en la presente población, existen pocas posibilidades de mejorar el peso al destete por selección.
Parámetros genéticos de rasgos de crecimiento en el ganado Cebú cubanocriollito
Para estimar los componentes de (co) varianza y los parámetros genéticos del peso al destete, a los siete meses de edad (PD), y del peso final,
a los 18 meses (PF), se utilizó una muestra de 67 373 registros de PD y 7 990 registros de PF de animales de la raza Cebú cubano, nacidos
entre 1988 y 2006, en cinco centros genéticos del país. El modelo estadístico para PD incluyó los efectos del grupo de contemporáneas
(vaquería–año–trimestre-sexo, la edad al destete como covariable lineal y la edad de la madre como lineal y cuadrática), el efecto aleatorio
del animal, el aleatorio materno, el efecto del ambiente permanente y el error. El modelo para PF comprendió el grupo de contemporáneas
(centro-año-cuatrimestre), el efecto del animal y del ambiente permanente. Los componentes de varianza, estimados mediante modelo
animal para el efecto directo de PD por el análisis univariado y bivariado, fueron similares y no tendieron a cambiar significativamente la
magnitud de la heredabilidad para los efectos directos (0.06 vs. 0.08) y maternos (0.06±0.01 vs. 0.05±0.01). Sin embargo, para el caso de
PF, los componentes de varianza para el efecto directo presentaron cambios importantes. Como resultado, la h2 fue mayor cuando se utilizó
el modelo bivariado (0.26±0.05) que al aplicar el univariado (0.16±0.03). La correlación genética entre el efecto directo y el materno para
peso al destete alcanzó un valor de -0.37±0.08 en el análisis univariado, y de -0.21±0.07 en el bivariado. Se concluye que la utilización de
un modelo animal, que considere simultáneamente el peso al destete y el peso final, incrementará la eficiencia de la selección para este
último carácter.
Parámetros genéticos para la persistencia de la lactación en vacas Siboney us...criollito
Con el objetivo de estimar los valores de heredabilidad y las correlaciones genéticas entre cinco medidas de persistencia usando
un modelo de regresión aleatoria con polinomios de Legendre, se analizaron 17,034 registros de producción de leche del día
del control de 2,086 vacas Siboney de Cuba (primera lactancia) que parieron entre 1995 y 2003 en 50 hatos. Los estimados de
heredabilidad para la persistencia de la lactación variaron de 0.18±0.02 a 0.29±0.02. Las correlaciones genéticas entre las
diferentes medidas de persistencia oscilaron de -0.71 a 0.95. Las correlaciones genéticas entre la producción de leche en los
distintos días del control, así como la producción acumulada hasta los 305 días de lactación (PL305) y las distintas medidas
de persistencia tomaron valores de -0.06 hasta 0.11. Basado en los niveles de heredabilidad y en las correlaciones genéticas de
las medidas de persistencia con la PL305, se concluye que es factible efectuar la selección conjunta para la PL305 y persistencia
de la lactación en el ganado Siboney utilizando la diferencia en el área bajo la curva entre el tercio final de la lactación (día
201 al 300) y el tercio inicial del día 1 al 100, (sumatoria de la contribución de cada día, en el periodo de los 61 a 280 días
de lactación, como una desviación de la producción en el día 60) como medidas de persistencia.
Componentes de (co)varianza del peso al destete en ganado Cebú cubanocriollito
Para estimar los componentes de (co)varianza del peso al destete en el ganado Cebú cubano, se dispuso de una muestra de 60 628 registros
de terneros, nacidos entre 1988 y 2006 en cinco empresas genéticas distribuidas a lo largo del país. Los datos se analizaron mediante el
procedimiento Reml, según seis modelos diferentes que alternaban combinaciones de efectos aleatorios genético aditivo del animal y
maternales genéticos y ambientales. Como efectos fijos comunes a todos los modelos, se consideró el grupo de contemporáneos (vaqueríaaño-
trimestre de nacimiento-sexo de la cría), la edad al destete del ternero como covariable lineal, y la edad de la madre, como covariable lineal
y cuadrática. Los resultados mostraron que, en el modelo donde se ignoraron los efectos maternales, la heredabilidad para los efectos directos
(0.31) fue sobreestimada con respecto a los modelos donde se consideraron (H ≈ 0.07). La heredabilidad para los efectos maternales resultó
similar a la de los efectos directos (0.08) para el modelo de mejor ajuste. Los efectos del ambiente permanente oscilaron entre 0.10 y 0.13 en
los modelos donde fueron considerados. La correlación genética aditiva entre los efectos directos y maternos tomó valores de -0.15 y -0.29.
Sin embargo, su inclusión no resultó significativa cuando se comparó con el modelo donde no se incluyeron. Los resultados indican que la
respuesta a la selección para la mejora genética del peso al destete en el ganado Cebú cubano no debe resultar suficientemente efectiva.
How to Create Map Views in the Odoo 17 ERPCeline George
The map views are useful for providing a geographical representation of data. They allow users to visualize and analyze the data in a more intuitive manner.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
2024.06.01 Introducing a competency framework for languag learning materials ...
J anim sci 1995-espinoza-2888-92
1. Effects of calcium soaps of fatty acids on postpartum reproductive activity in beef
cows and growth of calves
J. L. Espinoza, J. A. Ramirez-Godinez, J. A. Jimenez and A. Flores
J ANIM SCI 1995, 73:2888-2892.
The online version of this article, along with updated information and services, is located on
the World Wide Web at:
http://jas.fass.org/content/73/10/2888
www.asas.org
Downloaded from jas.fass.org by guest on August 18, 2011
2. Effects of Calcium Soaps of Fatty Acids on Postpartum Reproductive
Activity in Beef Cows and Growth of Calves1
J. L. Espinoza2, J. A. Ramirez-Godinez3, J. A. Jimenez, and A. Flores
´
Facultad de Zootecnia, Universidad Autonoma de Chihuahua, Perif.
´
Francisco R. Almada Km. 1, Apdo. Postal 4-28, C.P. 31031, Chihuahua, Chih. Mexico
ABSTRACT: Beef cows were used to determine the respectively). A similar tendency was observed in
influence of calcium soaps of fatty acids (CSFA) body condition scores in the same postpartum periods
incorporated in a range supplement on postpartum (4.1 vs 3.4, P < .01 and 3.6 vs 2.5, P < .01 for M and C,
reproductive characteristics and growth of calves. respectively). Concentrations of total cholesterol,
Cows were assigned randomly to receive 0 (C, n = 68) high-density lipoprotein cholesterol, low-density
or 125 g/d of CSFA (M, n = 66). Diets were lipoprotein cholesterol, very-low-density lipoprotein
isonitrogenous (23%) and were used during 105 d, cholesterol, and triglycerides were greater ( P < .01) in
beginning at 61 ± 36 d (range) precalving. Two blood
M than in C cows. Percentage of cycling (progesterone
samples were collected monthly (7-d intervals).
> 1 ng/mL) cows at 30 to 90 d postpartum was 38% in
Weights of calves at 35, 50, and 90 d of age and
weaning weight adjusted to 200 d of age were greater M and 22% in C ( P < .02). Percentage of pregnant
in M than in C (46.8 vs 43.8 kg, P < .05; 56.0 vs 50.6 cows during the first half of the breeding season was
kg, P < .01; 98.8 vs 91.8 kg, P < .01; and 186 vs 173 kg, greater ( P < .02) in M (62.5%) than in C cows
P < .01, respectively). Body weights at 35 and 50 d (35.5%). We concluded that CSFA incorporated in a
postcalving were greater in M than in C cows (334 range supplement during pre- and postpartum periods
and 310 kg, P < .01; 329 and 300 kg, P < .01, improved reproductive efficiency and growth of calves.
Key Words: Beef Cattle, Nutrition, Reproduction, Fat
J. Anim. Sci. 1995. 73:2888–2892
Introduction provision of linolenic acid (precursor to PGF2a) may
improve follicular recruitment and conception rates
Development of commercial products based on (Lucy et al., 1991b). Feeding CSFA increased plasma
calcium soaps of fatty acids ( CSFA) offers beef cattle LH in beef cows after calf removal (Hightshoe et al.,
producers a method of increasing energy density in 1991). Addition of supplemental fat to dairy and beef
range supplements without harming forage utilization cattle diets probably stimulates lipoprotein cholesterol
(Hightshoe et al., 1990). export by the intestine and increases circulating
Feeding bypass fat (Megalac) to dairy cows plasma LDL and HDL cholesterol concentration
resulted in greater conception rates (Ferguson et al., (Talavera et al., 1985). Feeding diets high in lipid
1988). The mechanism by which bypass fat influences content ( 8 % ) to cows and heifers resulted in increased
reproductive function is not well understood. Feeding concentration of HDL in serum and follicular fluid
fat may positively influence reproductive performance (Wehrman and Williams, 1989).
of cows by promoting an earlier return to positive The objectives of this study were to determine the
energy balance, earlier ovarian cycling postpartum, influence of Megalac, as a source of CSFA, on
and higher conception rates at first service (Butler reproductive efficiency during the postpartum period
and Smith, 1989; Carroll et al., 1990). In addition, in suckled beef cows maintained under pasture
conditions and to determine the influence of CSFA on
calf growth.
1We gratefully acknowledge Dennis Hallford, Dept. of Anim. and
Range Sci., New Mexico State Univ. for the progesterone assays and
for the preparation of this manuscript. Materials and Methods
2Present address: Universidad Autonoma de B.C.S. Apartado
´
´
Postal 19-B, La Paz, B.C.S., Mexico, C.P. 23000.
3To whom correspondence should be addressed. Multiparous Angus and Hereford × Angus cows ( n =
Received October 4, 1994. 134) ranging from 5 to 7 yr of age were blocked by
Accepted June 1, 1995. breed and age and assigned randomly to receive 1 kg/d
2888
Downloaded from jas.fass.org by guest on August 18, 2011
3. RESPONSE OF RANGE BEEF COWS AND CALVES TO BYPASS FAT 2889
of a control diet ( C, n = 68) containing grain sorghum (Sera-Pak, Ames Division). The VLDL was calculated
(80%), meat meal (18%), and urea ( 2 % ) (ME = 3.12 to be 1/5 of TG (Sera-Pak, Ames Division). Serum P4
Mcal) or the same diet plus 125 g/d of Megalac ( M, n was determined by RIA using a commercial kit
= 66; Church & Dwight Co., Princeton, NJ) as a (Diagnostic Products, Los Angeles, CA). Assays were
source of CSFA (ME = 3.8 Mcal). Diets were performed by the Animal Science Endocrinology
isonitrogenous (CP = 23%) and were fed during 105 d, Laboratory at New Mexico State University and the
beginning at 61 ± 3.9 d precalving. Birth weight of between- and within-assay coefficients of variation
calves was recorded. At three postpartum periods (35, were 5.2 and 8.1%, respectively.
50, and 95 d), body condition scores ( BC1, BC2, and Data for calf weight, weight and body condition
BC3 [Whitman, 1975]) and body weights ( BW1, BW2, score in cows, and lipid metabolites were analyzed by
and BW3) of cows were recorded. Weights of calves in analysis of variance in a completely randomized
the same postpartum periods ( WC1, WC2, and WC3) design using the GLM procedure (SAS, 1988). Preg-
and weaning weight ( WW) at 198 ± 6.0 d and 202 ± nancy rates at the first and second half and at end of
5.1 d of age in C and M calves, respectively, were the breeding season were compared by chi-square
recorded. All cows were exposed to mature Hereford (Steel and Torrie, 1980). The percentage of cycling
bulls (three bulls by group) that had passed breeding cows at 30 to 90 d and after 90 d postpartum were
soundness examinations (BIF, 1990) for a analyzed by the Catmod procedure (SAS, 1988).
190-d breeding period on two pastures under a
30-d rotational system. Two blood samples were
collected monthly from each cow (7-d intervals) on Results and Discussion
different postpartum periods, for determination of
total cholesterol ( CHOL) , high-density lipoprotein Calf Weight. Calf weights from birth to weaning are
cholesterol ( HDL) , low-density lipoprotein cholesterol shown in Table 1. The birth weight was similar ( P >
( LDL) , very-low-density lipoprotein cholesterol .05) for calves from M (31.8 kg) and C (30.6 kg)
( VLDL) , triglycerides ( TG) , and progesterone ( P4) . groups. Even though diets were not isoenergetic, the
The percentage of cycling cows at 30 to 90 d and > 90 d metabolizable energy provided by 125 g of M was not
postpartum was determined by the P4 concentration sufficient to stimulate greater fetal growth. Similar
( P 4 > 1 ng/mL = cycling cow). Blood was collected into research for birth weight in Hereford calves was
evacuated tubes via jugular venipuncture, maintained
reported by Stuedemann et al. (1968). However, WC1
on ice, allowed to clot, and centrifuged within 12 h
was greater ( P < .05) in calves from the M group
after collection. Serum was harvested and stored at
(46.8 kg) than in calves from the C group (43.8 kg)
−20°C until P4 and lipids (CHOL, HDL, LDL, VLDL,
and was affected by sex, age, and birth weight ( P <
and TG) were determined. Lipid profiles were deter-
.05). Male calves were heavier. A similar difference
mined by a commercial laboratory using automated,
was observed in WC2 ( P < .01), with values of 56.0
enzymatic procedures. The CHOL was determined in
and 50.6 kg for calves of M and C, respectively. The
serum after having been hydrolyzed and oxidized
enzymatically. In the oxidation process, H2O2 was WC3 and adjusted WW were greater ( P < .01) in
produced. Its presence of peroxidase, by reaction with calves of the M group, with a difference of 7 and 13 kg
4-amino-antipirine and fenol, was transformed in a for each variable, respectively (Table 1). Sex and age
coloring of quinonimine (Merck-Me ´xico, S. A.). The of calf affected ( P < .01) WC3, WW, and gain from
HDL were separated from chylomicrons, VLDL, and birth to weaning (132.8 kg in M vs 120.8 kg in C,
LDL by addition of a precipitating reagent (phos-
photungstic acid-magnesium chloride) to serum. After
centrifugation, the cholesterol content of the HDL Table 1. Weights of calves (kg) produced by cows
fraction remained in the supernatant and was deter- receiving either a control diet or Megalac
mined by the enzymatic colorimetric method using
cholesterol esterase, cholesterol oxidase, peroxidase, Diet
and the chromogen 4-aminophenazone/phenol (Sera-
Pak, Ames Division). The LDL was determined by Item Controla ± SEb Megalacc ± SEd P
difference between CHOL and HDL. The enzymatic Birth wt 30.6 ± .77 31.8 ± .70 > .05
colorimetric method for TG determination is based on Days of age
the principle that glycerol released from hydrolysis of 35 (WC 1 ) 43.8 ± 2.67 46.8 ± 2.53 < .05
triglycerides by lipoprotein lipase is converted by 50 (WC 2 ) 50.6 ± 2.47 56.0 ± 2.12 < .01
glycerolquinase into glycerol-3-phosphate, which is 95 (WC 3 ) 91.8 ± 4.01 98.8 ± 3.60 < .01
oxidized by glycerolphosphate oxidase to dihydrox- Weaning wte 173.0 ± 2.98 186.0 ± 2.72 < .01
yacetone phosphate and hydrogen peroxide. In the a1 kg/d during 105 d, 68 cows with calf.
b,dBased on 68 and 66 calves, respectively.
presence of peroxidase, hydrogen peroxide oxidizes cControl diet mixed with 125 g/d of Megalac during 105 d, 66
the chromogen 4-aminophenasone/N-ethyl-N-(3-sul- cows with calf.
phopropyl)-m-anisidine to a violet-colored compound eAdjusted to 200 d of age.
Downloaded from jas.fass.org by guest on August 18, 2011
4. 2890 ESPINOZA ET AL.
respectively). The WW adjusted to 200 d of age was Table 3. Reproductive performance of cows fed a
greater in M calves (186 kg) than C calves (173.8 control diet or a diet supplemented with Megalac
kg).
The increase in calf weights observed in the M Diet
group can be explained possibly by a greater milk
Item Controla Megalacb P
production of cows fed bypass fat (Coppock and Wilks,
1991). However, in those studies dairy cows were used Percentage cycling
and were fed greater levels of bypass fat. Moreover, 30 to 90 dc 22.0 38.0 < .02
> 90 dd 72.0 61.0 > .05
Knapp and Grummer (1991) observed that milk fat
FHBSe 37.5 62.5 < .02
percentage was greater for Holstein cows fed 5 than EBSf 84.7 90.9 > .05
for those fed 0% fat (3.46 vs 3.15%, respectively). a1 kg/d during 105 d, 68 cows with calves.
Weight and Body Condition Score in Cows. Body bControl diet mixed with 125 g of Megalac during 105 d, 66 cows
weight was greater ( P < .01) in M cows at 35 and 50 d with calves.
cCycling cows at 30 to 90 d postcalving.
postpartum (BW1 = 334 vs 310 kg; BW2 = 329 vs 299 dCycling cows after 90 d postcalving.
kg). However, BW3 was similar ( P > .05) between ePregnant cows at first half of a 190-d breeding season.
groups (376 vs 360 kg in M and C, respectively). This fPregnant cows at end of a 190-d breeding season.
similarity at period 3 was expected because BW3 was
obtained 30 d after treatments ended, when cows were
on common pasture. Body condition scores (BC1, BC2, (1975) reported that beef calves with greater
and BC3) followed a trend similar to that of BW (4.1 preweaning growth had more serum cholesterol than
vs 3.4, P < .01; 3.6 vs 2.25, P < .01; and 6.2 vs 5.9, P > did calves that gained less rapidly. Furthermore,
.05, for M and C, respectively). Body condition score cholesterol in calves declined after weaning. Serum
change between BC2 and BC3 was greater ( P < .01) concentration of lipid metabolites (CHOL, HDL, LDL,
in C than in M. Body condition score, body weight at VLDL, and TG) were greater ( P < .01) in cows fed
second period, and body condition score change CSFA (Table 2). A similar response was observed by
between BC2 and BC3 were affected ( P < .01) by Peters and Corah (1993) in beef heifers fed .454 kg of
postpartum days. The tendencies in body weight and Megalac. Sklan et al. (1989) reported that serum
condition scores at the start of the postpartum period levels of CHOL and HDL were greater between 15 and
support observations that energy intake in this period 29 d postpartum in CSFA-supplemented cows. Greater
is less than required (Haresign, 1988). Williams concentrations of CHOL, HDL, and TG were also
(1989) found that body condition score remained observed by Morgan and Williams (1989) in cows fed
constant through the first 100 d postpartum, and all diets with elevated lipids. Williams (1989) observed
cows exhibited a slight decrease (13.7 kg) in BW that that mean concentrations of total CHOL and TG in
did not differ between groups (8% vs 2.8% dietary control animals (2.8% dietary lipid) were lower than
lipid). However, in our study, feeding 125 g/d of in animals fed a high-lipid ( 8 % ) diet during the 4th,
Megalac maintained a greater body weight and body 5th, and 6th wk after calving. By the 4th wk, plasma
condition score during the first 50 d postpartum. concentrations of CHOL and TG in cows supplemented
Lipid Metabolites. Plasma concentrations of with a high-fat diet were greater than control values
cholesterol increased with ingestion of milk lipids by by 1.7- and 1.4-fold, respectively. The greater concen-
suckling calves (Carroll and Hamilton, 1973). O’Kelly tration of metabolites can be explained by increased
intestinal secretion of lipoproteins with a high content
of TG such as VLDL.
Table 2. Serum lipids (mg/dL) in cows fed either a Reproductive Performance. The percentage of cycling
control diet or a diet supplemented with Megalac cows 30 to 90 d after calving was greater ( P < .02) in
M (38%) than in C (22%). However, after 90 d
Diet
postpartum, the percentage of cycling cows was
similar ( P > .05) between treatments (61 vs 72% for
Metabolitea Controlb ± SEc Megalacd ± SEe P M and C, respectively [Table 3]).
CHOL 146.2 ± 7.62 186.6 ± 6.99 < .01 The percentage of pregnant cows at end of the
HDL 67.8 ± 4.49 81.4 ± 4.12 < .02 breeding season was similar ( P > .05) between
LDL 97.1 ± 9.4 130.1 ± 8.6 < .01 treatments (91 vs 84% in M and C, respectively);
VLDL 18.7 ± 1.25 26.0 ± 1.15 < .01
TG 94.0 ± 6.27 130.0 ± 5.75 < .01
however, 62.5% of cows in M were pregnant during the
aCHOL = total cholesterol; HDL = high-density lipoprotein
first half of the breeding season, compared with 35.5%
cholesterol; LDL = low-density lipoprotein cholesterol; VLDL = very- ( P < .02) in the C group (Table 3). Similar results
low-density lipoprotein cholesterol; TG = triglycerides. were reported by Ferguson et al. (1988), who
b1 kg/d during 105 d, 68 cows with calf.
c,eBased on 32 and 38 samples, respectively.
observed greater conception rates and fewer open days
dControl diet mixed with 125 g/d of Megalac during 105 d, 66 in dairy cows supplemented with bypass fat. In
cows with calf. contrast, cows fed CSFA (Sklan et al., 1991) initiated
Downloaded from jas.fass.org by guest on August 18, 2011
5. RESPONSE OF RANGE BEEF COWS AND CALVES TO BYPASS FAT 2891
ovarian cyclicity later than controls; however, after calving in our study may be related to a greater CHOL
cyclicity began, more fat-fed cows than controls had available for P4 synthesis in M cows. This speculation
normal cycle length (18 to 26 d). Conception rate was is based on a study in which 80% of lipid-fed females
greater in cows fed CSFA and number of open days exhibited at least slight increases in baseline P4 before
was reduced. induced estrous cycle with GnRH treatment, compared
Feeding diets that contain fats and that are higher with 37% of controls (Williams, 1989). These observa-
in energy may partially alleviate negative energy tions suggest that fat supplement affects the “quality”
balance and stimulate ovarian function (Lucy et al., of the corpus luteum rather than the number or
1991b). Hypothetically, the additional dietary energy quantity of corpora lutea.
(and not the CSFA) stimulated the development of
follicles and led to larger ovarian follicles in fat-fed
cows. To test this hypothesis, Lucy et al. (1991a) Implications
conducted an experiment in which three diets were
formulated for postpartum lactating cows: a control The calcium soaps of fatty acids may be used in
diet (no CSFA), a diet containing CSFA with energy relatively small amounts in beef cow diets on range to
density equivalent to that of the control diet, and a improve reproductive efficiency during the postpartum
third diet that contained both additional energy and period. In this study, feeding Megalac resulted in more
CSFA. In that experiment, after 4 wk of feeding the cows cycling at 30 to 90 d postpartum and more cows
experimental diets, preovulatory follicles were larger pregnant during the first half of the breeding season.
in diameter in cows fed the CSFA diets with either These effects would result in older calves during the
normal or high energy levels than in cows fed the next production cycle and a greater efficiency in the
control diet. herd. Moreover, calves produced by Megalac-sup-
Although mechanisms have not yet been deter- plemented cows were heavier than those produced by
mined, mean serum concentrations of LH measured controls, which could justify addition of Megalac to
during three periods surrounding calf removal were pre- and postpartum cattle diets.
greater in cows receiving CSFA than in controls
(Hightshoe et al., 1991). Similar responses were
observed by Lucy et al. (1989), who found that basal Literature Cited
LH was increased in early postpartum dairy cows
BIF. 1990. Guidelines for Uniform Beef Improvement Programs
receiving CSFA. However, feeding fat (CSFA) did not
(6th Ed.). Beef Improvement Federation, Oklahoma State
influence the basal, smoothed mean concentration and Univ., Stillwater.
average LH amplitude (Lucy et al., 1991b). Reports of Butler, W. R., and R. D. Smith. 1989. Interrelationship between
pituitary response to GnRH stimulation in intact beef energy balance and postpartum reproductive function in dairy
cows consuming hyperlipidemic diets indicated that cattle. J. Dairy Sci. 72:767.
Carroll, D. J., R. R. Grummer, and F. C. Mao. 1992. Progesterone
neither GnRH-induced LH release nor tonic release
production by cultured luteal cells in the presence of bovine low
was affected (Johnson et al., 1987; Morgan and and high density lipoproteins purified by heparin affinity chro-
Williams, 1989). In contrast, De Luna et al. (1982) matography. J. Anim. Sci. 70:2516.
fed protected lipids to ovariectomized cows in the early Carroll, D. J., M. J. Jerred, R. R. Grummer, D. K. Combs, R. A.
postpartum period and observed greater concentra- Pierson, and E. R. Hauser. 1990. Effects of fat supplementation
and immature alfalfa to concentrate ratio on plasma progester-
tions of LH in response to exogenous GnRH.
one, energy balance, and reproductive traits of dairy cattle. J.
In addition to their more obvious effects on energy Dairy Sci. 73:2855.
balance, CSFA may increase postpartum release of Carroll, K. K., and R.M.G. Hamilton. 1973. Plasma cholesterol levels
uterine prostaglandin F2a, which has been implicated in suckling and weaned calves, lambs, pigs and colts. Lipids 8:
as an important modulator in the initiation of estrous 635.
Coppock, C. E., and D. L. Wilks. 1991. Supplemental fat in high-
cycles after calving (Madej et al., 1984). However,
energy rations for lactating cows: Effects on intake, digestion,
feeding fat (CSFA) did not influence 15-keto- milk yield, and composition. J. Anim. Sci. 69:3826.
13,14-dihydro-prostaglandin F2a (Lucy et al., 1991b). De Luna, C. J., W. H. Brown, D. E. Ray, and T. N. Wagner. 1982.
Although the mechanisms by which changes in lipid Effects to protected fat supplement on GnRH induced LH
metabolism may influence ovarian function have not release in ovariectomized and early postpartum beef cows. J.
been determined, a wide array of potential pathways Anim. Sci. 55(Suppl. 1):348 (Abstr.).
Ferguson, J. D., T. L. Blanchard, and W. Chalupa. 1988. Protein,
exists (Williams, 1989). The P4 production by luteal fats and fertility in dairy cows. Bovine Proc. 20:112.
cells was greater with highest HDL and LDL in vitro ´
Haresign, W. 1988. Condicion corporal, produccion de leche y
(Carroll et al., 1992). Granulosa cells of heifers fed ´
reproduccion en el ganado vacuno. En: W. Haresign and D.J.A.
high-fat diets ( 8 % ) during 30 d released 2.1- to ´
Cole (Ed.) Avances en Nutricion de los Rumiantes. p 1.
3.5-fold more pregnenolone and P4 in vitro, and the Acribia, Spain.
Hightshoe, R. B., R. C. Cochran, L. R. Corah, D. L. Harmon, and E.
luteal activity was 18% greater (Wehrman et al., S. Vanzant. 1990. Influence of level and source of rumen-escape
1991). Based on these studies, we speculate that the lipid in a supplement on forage intake and digestibility. J.
greater percentage of cycling cows at 30 to 90 d after Anim. Sci. 68(Suppl. 1):571 (Abstr.).
Downloaded from jas.fass.org by guest on August 18, 2011
6. 2892 ESPINOZA ET AL.
Hightshoe, R. B., R. C. Cochran, L. R. Corah, G. H. Kiracofe, D. L. Peters, C. W., and L. R. Corah. 1993. Effect of rumen-escape lipid on
Harmon, and R. C. Perry. 1991. Effects of calcium soaps of fatty endocrine profiles, lipid metabolites and follicular dynamics
acids on postpartum reproductive function in beef cows. J. during estrus synchronization in primiparous beef heifers. J.
Anim. Sci. 69:4097. Anim. Sci. 71(Suppl. 1):72 (Abstr.).
Johnson, M. S., T. N. Wagner, and D. E. Ray. 1987. Effects of SAS. 1988. SAS/STAT® User’s Guide (Release 6.03). SAS Inst. Inc.,
elevated serum lipids on luteinizing hormone response to Cary, NC.
gonadotrophin releasing hormone challenge in energy deficient Sklan, D., E. Bogin, Y. Avidar, and S. Gur-Arie. 1989. Feeding
anestrous heifers. Theriogenology 27:421. calcium soaps of fatty acids to lactating cows: Effect on produc-
Knapp, D. M., and R. R. Grummer. 1991. Response of lactating dairy tion, body condition and blood lipids. J. Dairy Res. 56:675.
cows to fat supplementation during heat stress. J. Dairy Sci. Sklan, D., U. Moallem, and Y. Folman. 1991. Effect of feeding
74:2573. calcium soaps of fatty acids on production and reproductive
Lucy, M. C., R. L. De La Sota, C. R. Staples, and W. W. Thatcher. responses in high producing lactating cows. J. Dairy Sci. 74:
1991a. Effect of dietary calcium salts of long chain fatty acids 510.
(CaLCFA), energy intake, and lactation on ovarian follicular Steel, R.G.D., and J. H. Torrie. 1980. Principles and Procedures of
dynamics in Holstein dairy cows. J. Anim. Sci. 69(Suppl. 1): Statistics: A Biometrical Approach (2nd Ed.). McGraw-Hill
451 (Abstr.). Publishing Co., New York.
Lucy, M. C., C. R. Staples, F. M. Michel, W. W. Thatcher, and D. J. Stuedemann, J. A., J. J. Guenther, S. A. Ewing, R. D. Morrison, and
Bolt. 1991b. Effect of feeding calcium soaps to early postpartum G. V. Odell. 1968. Effect of nutritional level imposed from birth
dairy cows on plasma prostaglandin F2 alpha, luteinizing hor- to eight months of age on subsequent growth and development
mone and follicular growth. J. Dairy Sci. 74:483. patterns of full-fed beef calves. J. Anim. Sci. 27:234.
Lucy, M. C., W. W. Thatcher, F. J. Michel, and C. R. Staples. 1989. Talavera, F. C., C. S. Park, and G. L. Williams. 1985. Relationships
among dietary lipid intake, serum cholesterol and ovarian func-
Effect of dietary calcium soaps of long chain fatty acids
tion in Holstein heifers. J. Anim. Sci. 60:1045.
(Megalac) on plasma prostaglandin F metabolite (PGFM),
Wehrman, M. E., T. H. Welsh, and G. L. Williams. 1991. Diet-
LH, energy balance, and follicular populations in early postpar-
induced hyperlipidemia in cattle modifies the intrafollicular
tum dairy cattle. J. Anim. Sci. 67(Suppl. 1):389 (Abstr.).
cholesterol environment, modulates ovarian follicular dynamics
Madej, A., H. Kindahl, W. Woyno, L. E. Edquist, and R. Stupnicki. and hastens the onset of postpartum luteal activity. Biol.
1984. Blood levels of 15-keto-13,14-dihydro-prostaglandin F2 Reprod. 45:515.
alpha during the postpartum period in primiparous cows. Wehrman, M. E., and G. L. Williams. 1989. Effect of dietary lipid
Theriogenology 21:279. intake on serum and ovarian follicular lipid metabolites and on
Morgan, A. R., and G. L. Williams. 1989. Effects of body condition follicular populations in beef females. Proc. So. Sect. Am. Soc.
and postpartum dietary lipid intake on lipid metabolism and Anim. Sci. p 59 (Abstr.).
pituitary function of beef cows. J. Anim. Sci. 67(Suppl. 1):385 Whitman, R. W. 1975. Weight change, body condition and beef cow
(Abstr.). reproduction. Ph.D. Dissertation. Colorado State Univ., Fort
O’Kelly, J. C. 1975. Growth and lipid metabolism in genetically Collins.
different types of calves in a tropical environment. Growth 39: Williams, G. L. 1989. Modulation of luteal activity in postpartum
125. beef cows through changes in dietary lipid. J. Anim. Sci. 67:785.
Downloaded from jas.fass.org by guest on August 18, 2011
7. Citations This article has been cited by 3 HighWire-hosted articles:
http://jas.fass.org/content/73/10/2888#otherarticles
Downloaded from jas.fass.org by guest on August 18, 2011