This study tested different doses of phytase and calcium levels in corn/soybean meal-based diets for broilers with reduced nutrient density. Nine treatment groups were tested including a positive control diet based on breeder recommendations. All phytase treatment groups compensated for nutrient reductions and achieved equal or better growth performance than the positive control. Higher phytase doses of 2000 FTU/kg improved body weight gain and feed conversion ratio compared to 500 FTU/kg, while 1000 FTU/kg showed lower feed conversion. Reducing calcium levels in a stepwise manner lowered feed costs and improved energy efficiency, with the highest calcium reduction performing best. Bone ash was not affected. The results suggest that higher phyt

1. S1- 0211 Effect of phytase dose and
Ca level on performance in broilers
fed corn soybean meal based diets
with reduced nutrient density
Yueming Dersjant-LI1
, Wenting Li1
, Luis Rome-
ro1
, Ceinwen Evans1
, Arun Kumar2
1. Danisco Animal Nutrition, DuPont Industrial
Biosciences. Marlborough, UK; 2. The Universi-
ty of Queensland, Gatton Qld 4343, Australia
Corresponding author: yueming.dersjant- li@du-
pont.com
This study tested the effect of phytase dose and Ca
level on performance of broilers fed a corn/SBM
based diet. Nine treatments were tested including a
positive control (PC, based on breeder’s recommen-
dations). A basal diet was formulated without Ca
and P supplements and with reduction of 68 kcal
ME/kg, on average 0.02% dig AA and 0.03% Na vs
PC. This basal diet was supplemented with
Buttiauxella sp. phytase, DCP and limestone: 3 di-
ets at 500 FTU/kg with reduction of 0.146% AvP,
0.134, 0.164, 0.234% Ca respectively (low, medi-
um, high) vs PC; 3 diets at 1000 FTU/kg with re-
duction of 0.174% AvP and 0.159, 0.189, 0.234%
Ca; 2 diets at 2000 FTU/kg with 0.183% AvP,
0.196 and 0.234% Ca reduction (medium and
high). Filler was used to maintain the same ingredi-
ent composition in all phytase treatments except
DCP and limestone. Ross 308 male broilers were
used with 8 replicates (20 birds/pen) in a ran-
domised block design. Pelleted diets were offered
ad libitum for 0-42 days. At 42d, tibia samples (5
birds/pen) were collected. No Ca level and phytase
dose interaction was found, the main effects of phy-
tase dose and Ca level were tested by Tukey’s HSD
using JMP 11 (SAS). All phytase treatments com-
pensated nutrient reduction, with BWG and FCR
equal to or better than PC (superior to the breeder
targets). Phytase at 2000FTU/kg improved BWG (0-
21d), reduced FCR and feed cost/kg BWG (0-10d)
vs 500FTU/kg, while 1000FTU/kg showed lower
FCR (0-21d). Linear or curve-linear responses were
observed with increasing phytase dose on BWG
and FCR. Reducing Ca level lowered feed cost/kg
BWG and improved energy efficiency in a step
wise manner, the high Ca reduction showed lower
feed cost/kg BWG and higher energy efficiency (P <
0.05) than low Ca reduction, suggesting a better Ca/
P balance. Bone ash was not affected. The data sug-
gest that high phytase dose (1000- 2000FTU/kg)
may lead to production benefit, while the impact of
Ca level need to be further evaluated under differ-
ent dietary conditions.
Keywords: broilers, buttiauxella phytase, calcium,
available p, production performance
S1- 0212 Development of calibra⁃
tions for evaluation of calcium level
in limestone by using near infrared
reflectance spectroscopy
Chayon Barma
Nutrition & Quality Assurance Deartment, Kazi
Farms Limited (Feed Mill), Thakurgaon, Bangla-
desh
Corresponding author: chayon.nutrition@kazi-
farms.com
Near infrared reflectance spectroscopy (NIRs) is
an important tool for rapid analysis and predic-
tion of feed ingredients. Calcium is very impor-
tant for both in broiler and laying chicken’s diet
and limestone is the best source for that. In Ban-
gladesh, we collect limestone mainly from Bhu-
tan and sometimes from Vietnam. Near infrared
reflectance spectra were collected from a FOSS
5000 Reflectance Spectrophotometer using a
Qurtz Quarter cup sampling device. Multivariate
analysis was performed for the development of
calibration equations of nutrients by WinISI 4.6
software to relate the spectral data and corre-
sponding concentration values of limestone.
Around 1000 sample data were centered using
the partial least squares algorithm, and spectral
outliers were identified from each calibration.
The accuracy of the calibration models was vali-
dated by root mean square error cross validation
(RMSECV), root mean square error of estima-
tion and correlation coefficient (R2
) between the
measured values of nutrient component deter-
mined by analytical laboratory vs. predicted val-
ues. Equation was selected on the basis of lowest
Standard Error of Cross Validation (SECV) and
highest 1 minus the Variance (1-VR) for calcium
(Ca) content. It is concluded that NIRs could po-
tentially be used to predict Ca content in Lime-
stone.
Keywords: NIR, calibration, poultry, limestone
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