Main Article Content
Abstract
Ewes are seasonally polyestrous animals, so that the young are born during the most favorable time of the year, spring. The length of the sexual season varies with day length, breed, and nutrition. This seasonality is governed by photoperiodicity, with estrus activity beginning during a period of decreasing day length. Puberty, or the age at first ovulation, occurs at 6 to 9 months. After puberty, ewes come into heat. The length of the normal estrous cycle is 17 days (ranging from 14 to 19 days). The estrous cycle consists of four phases: estrus, metestrus, diestrus, and proestrus, which can be simply divided into the follicular phase and the luteal phase. In many breeds of ewe, two or more ova are shed during estrus. If copulation and gestation occur, the animal enters anestrus. If not, the estrous cycle continues during the seasonal period and transitions into the non-seasonal period. Further studies are needed to improve reproductive efficiency in local ewes.
Keywords
Article Details
Copyright (c) 2024 Reserved for Kabul University.
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
References
- Dooley MP, Pineda MH. Patterns of Reproduction. In: Pineda MH, Michael PD editors. McDonalds Veterinary Endocrinology and Reproduction. 50th ed. Iowa State Press. Blackwell Publishing Company. 2003; Pp 377-391.
- Dusty WN, Pugh DG. Handling and Examining Sheep and Goats. In: Pugh DG, Baird AN. Sheep and Goat Medicine. 2nd ed. USA. Elsevier Saunders. 2012; P 6.
- Ian G. Reproductive Technologies in Farm Animals. 2nd ed. Cabi Publishng. 2017; Pp 140-143, 146-148,
- (4) Ian G. The Ewes Oestrous Cycle and Seasonal Breeding Activity. In: Ian G. Controlled Reproduction in Sheep and Goats. Eastbourne, UK. Cab International. 2004; Pp 53-77.
- James SE. Endocrine Manipulation of Reproduction. In: James ES. Applied Animal Endocrinology. Cabi Publishng. 2003; Pp 154-189.
- Misty AE, Roberts JF, Baird AN, Stan B, Pugh DG. Theriogenology of Sheep and Goats. In: Pugh DG, Baird AN. Sheep and Goat Medicine. Elsevier Saunders. 2012; Pp 150-226.
- Paul JP, Cassandra LP, Kelly MS. Diseases of the Respiratory System. In: Pugh DG, Baird AN. Sheep and Goat Medicine. 2nd ed. Elsevier Saunders. 2012; P 135.
- Pineda MH. The Biology of Sex. In: Pineda MH, Michael PD. McDonalds Veterinary Endocrinology and Reproduction 50th ed. Iowa State Press. Blackwell Publishing Company. 2003; Pp 201-211.
- Pineda MH. Reproductive Patterns of Sheep and Goats. In: Pineda MH, Michael PD editors. McDonalds Veterinary Endocrinology and Reproduction. 50th ed. Iowa State Press. Blackwell Publishing Company. 2003; Pp 435-452.
References
Dooley MP, Pineda MH. Patterns of Reproduction. In: Pineda MH, Michael PD editors. McDonalds Veterinary Endocrinology and Reproduction. 50th ed. Iowa State Press. Blackwell Publishing Company. 2003; Pp 377-391.
Dusty WN, Pugh DG. Handling and Examining Sheep and Goats. In: Pugh DG, Baird AN. Sheep and Goat Medicine. 2nd ed. USA. Elsevier Saunders. 2012; P 6.
Ian G. Reproductive Technologies in Farm Animals. 2nd ed. Cabi Publishng. 2017; Pp 140-143, 146-148,
(4) Ian G. The Ewes Oestrous Cycle and Seasonal Breeding Activity. In: Ian G. Controlled Reproduction in Sheep and Goats. Eastbourne, UK. Cab International. 2004; Pp 53-77.
James SE. Endocrine Manipulation of Reproduction. In: James ES. Applied Animal Endocrinology. Cabi Publishng. 2003; Pp 154-189.
Misty AE, Roberts JF, Baird AN, Stan B, Pugh DG. Theriogenology of Sheep and Goats. In: Pugh DG, Baird AN. Sheep and Goat Medicine. Elsevier Saunders. 2012; Pp 150-226.
Paul JP, Cassandra LP, Kelly MS. Diseases of the Respiratory System. In: Pugh DG, Baird AN. Sheep and Goat Medicine. 2nd ed. Elsevier Saunders. 2012; P 135.
Pineda MH. The Biology of Sex. In: Pineda MH, Michael PD. McDonalds Veterinary Endocrinology and Reproduction 50th ed. Iowa State Press. Blackwell Publishing Company. 2003; Pp 201-211.
Pineda MH. Reproductive Patterns of Sheep and Goats. In: Pineda MH, Michael PD editors. McDonalds Veterinary Endocrinology and Reproduction. 50th ed. Iowa State Press. Blackwell Publishing Company. 2003; Pp 435-452.