Estrus behavior of Baladi heifers during cold and hot season in Egypt.
Abstract: Nineteen baladi heifers aged 274± 13.0 days average live body weight of 140± 12.0 kg were divided into two groups (CS and HS) according to their birth season to study the effect of season of birth on age and body at puberty. On the other hand, the effect of season at puberty on estrus behaviour development, regularity of of ovarian cycles and changes in serum progesterone post puberty well also studied. Heifers were checked for heat three times daily, in the presence of a teaser. Blood samples were collected regularly, at 3-4 day intervals for progesterone determination to ovarion activity post puberty.
The main results obtained could be summarized as follows :-
1- The average age and body weight at first true estrus ( puberty) were 444.2±16.7 days and 227±12.1 kg, respectively. The differences between the two seasons were insignificant for age and body weight at puberty.
2- Post puberty estrus cycles length showed a gradual increase from the 1st to the 4th cycles. Season at puberty had insignificant effect on post puberty length cycles.
3- Heifers reached puberty at CS showed significantly ( P<0.05) lower percentage of quiet ovulation than those of heifers reached puberty at HS.
4- Estrus behaviour showed a gradual increase in strength from the 1st to the 4th estrus cycles. The heifers reached puberty at CS was exhibited more pronounced behavioural signs than those of the heifers reached puberty at HS.
5- Progesterone concentrations in the serum during the first estrus cycle of puberty was lowest at estrus ( 0.4± 0.1ng/ml) and then increased to a maximum of 5.2± 1.0 ng /ml on day 10 of the cycle. The concentration decreased rapidly during the last 2 days of cycle, reaching low (0.4±0.1) level on the day before estrus.
Key words : Heifers, Baladi, Puberty, estrus behaviour.
Publication year 2001
Pages 1085-1095
Availability location معهد بحوث الانتاج الحيوانى- شارع نادى الصيد- الدقى - الجيزة
Availability number
Organization Name
serial title Minufiya Journal Agriculture Research.
Department Cattle Breeding Research Department
Author(s) from ARC
Agris Categories Animal physiology - Reproduction
AGROVOC
TERMS		 Cold season. Egypt. Heifers. Sexual maturity. Warm season.
Publication Type Journal
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