Sexual maturity occurs when the reproductive organs are developed enough to reproduce. Puberty begins the process when the gonads become capable of releasing eggs or sperm. Several factors can influence the age of puberty in animals, including genetics, environment, nutrition, and body weight. The document discusses puberty and sexual maturity in various species like cattle, sheep, goats, horses, and pigs. It covers the hormonal and physical changes during puberty as well as average ages and factors that can affect the timing of puberty.

1. Presentedto :
Dr. Pratibha Singh
[Instructor]
College of Veterinary & Animal Sciences
SVP University of Agriculture & Technology,
Meerut - 250110
Presentedby :
Surya Kant Agarwal
[V-3098/14]
Topic
Puberty and Sexual Maturity
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 Sexual maturity is the age or stage when an organism can
reproduce
 It is brought about by a maturing of the reproductive
organs and the production of gametes
 Puberty is defined as the age at which the female or male
gonads become capable of releasing the gametes
(Oocytes or Spermatozoa)
 Puberty in females is defined as the age at the first
expressed estrus with ovulation (It should not be
considered sexual maturity)
Introduction

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 Onset of puberty normally occurs at a certain age relative to the
animal’s body weight. Heifers must attain approximately two thirds
their adult sizes before they reach puberty
 It represents the initiation of estrous cycle
 The word puberty
originated from latin word
"pubscere" that means "to
be covered with hair". The
original definition that
relates to the presence of
hair in certain anatomical
regions, obviously does not
hold good to other animals

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PHYSICAL CHANGES OF PUBERTY
• Female secondary sex characteristics
• Male secondary sex characteristics
HORMONAL CHANGES OF PUBERTY
 Gonadotropin-Releasing Hormone
 Gonadotropins
 Adrenal steroids
 Ovarian development
 Testis development
 Role of GH, IGF-I and insulin
 Leptin

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Sexual maturity
 The female become capable for insemination and
pregnancy
 Puberty occurs when gonadotropins (FSH and LH) are
produced at high enough levels to initiate follicle growth,
oocyte maturation, and ovulation
 If animals are bred at puberty, a high percentage will have
difficulty with parturition
 When they approach mature levels, they stimulate
resumption of oocyte maturation and ovulation occurs

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Sexual maturity
Age at pubety is affected by both genetic and
environmental factors
Genetic factors can be seen by comparing or breeds
within a species
Average age at puberty in different species is :
• 7 to 18 months for cows (Maturity: 30 months)
• 4 to 5 months for does (Maturity: 6-8 months)
• 7 to 10 months for ewes (Maturity: 12-18 months)
• 12 to 24 months for mares (Maturity: 36 months)
• Bitch :6-20 month queen 7-12 month

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Factors affecting timing of puberty
 A number of environmental factors have a pronounced effect on
age at puberty
In general, any factor which slows growth rate, thus preventing
expression of full genetic potential, will delay puberty
• High environmental temperature delays puberty
• Age at puberty in sheep and goats is affected by months of birth
because it affects their age at the onset of their breeding season
For example, ewes born in January will be older at puberty than
those born in March

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 Interaction with the opposite sex
 Influence of sex: Female attains puberty at an earlier age
 Breed: Small breeds attain puberty at an earlier stage. eg. Nine
months in Jersey and 11 months in Holstein Friesian.
Dairy breeds appear to reach puberty earlier than beef breeds
 Climatic influence: Animals in the tropics attain puberty at an
early age
 Seasonal influence: Breeding season affects onset of puberty. Eg.
Ewe lambs born in early spring attain puberty in the fall i.e.,
within 180 days. But ewe lambs born in late spring and early
summer attain puberty only in the fall of the next breeding
season i.e., only after 400 days
 Plane of nutrition: High plane of nutrition leads to early puberty
and undernourishment delays onset of puberty
 Body weight: Sheep attain puberty after reaching a body weight
of 40 kg.

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 Patterns of seasonal breeding range from species that have
one period of estrus each year (Monoestrus) to species that
have a series of estrous cycles limited to a portion of year
(seasonally polyestrus)
 In temperate climates many species are seasonal breeders.
Sheep, goats and horses are examples of them
 This means that periods of sexual activity (the oestrus
season) are alternated with periods of sexual inactivity
(the anoestrus season)
 In sheep, sexual activity starts when the day length
shortens (short-day breeders), and in horses sexual
activity starts when day length increases (long-day
breeders)

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PUBERTY AND SEXUAL MATURITY IN CATTLE
 With good nutritional management, most cattle reach puberty
between 8 and 13 months of age. Failure to exhibit estrus beyond
this time is called Prepubertal Anestrus
 To begin with, the history of the individual or the group of heifers
will provide the key to the etiology
 If the problem exists in a single heifer of the same age as rest of the
cycling heifers in the group it is probably related to abnormal
reproductive tract such as
 Freemartinism,
 Hermaphrodite
 Aplasia of the mullerian duct
 Any debilitating disease such as chronic pneumonia can delay
puberty by decreasing rate of gain, which appears to be a functional
dietary problem

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 If delayed puberty occurs in a group of heifers of the same ages or
a group of mixed ages then the problem is one of management
 Infectious diseases like blue tongue, and bovine diarrhoea virus
may result in acute ovaritis and subsequently ovarian atrophy
thus causing anestrus
 Animals may respond to hormonal therapy but promptly return
to anestrus once therapy is withdrawn
 The use of growth stimulation implants in prepubertal heifers can
delay pubertal estrus and affect future fertility

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PUBERTY AND SEXUAL MATURITY IN GILTS
 In hybrid gilts, puberty usually occurs at around 160 days or age but
it is breed dependent
 Puberty may be delayed by poor environmental conditions, cold,
sunburn and poor light
 Poor nutrition acts by reducing growth rates or by causing
deficiencies in particular nutrients
 Clinical signs of delayed puberty consist simply of the failure of gilts
to show estrus (enlargement of the vulva, reddening of the vulva,
remaining still for back pressure, clustering round a boar) by the
time they would be expected to have reached puberty based on
previous experience with the breed

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 For the accurate diagnosis, the age of the animals under
examination must be known and individual animals must be
identified or removed from the group when estrus is first detected
 Prevention of delayed puberty depends upon correcting the
management factors –
 Gilts should be reared to 5-6 months of age in groups of 6-30, isolated from
boars, with 12-16 hours light of adequate intensity at a temperature of about
20°C and given food. Disease should be controlled
 Gilts which have reached 160-210 days of age should be exposed to
vasectomised boars or housed in sight, smell and touch of a smelly older boar.
Estrus should then be observed. If not, then gilts can be tested with another
boar daily, taking the gilt to the boars
 Treatment with gonadotrophic hormones induces estrus in pre-pubertal gilts.
Gilts should be reared to 5-6 months of age in isolation from boars, injected
with gonadotrophic hormone preparations and then allowed contact with
boars for 15-20 minutes per day. Ninety percent of gilts will develop estrus
within 5-7 days. They should not be mated at this estrus

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