Determining the factors affecting the gestational length in sheep.

Hilal Tozlu Celik,İbrahim Kiper,Fatih Ahmet Aslan,Metehan Eser Kahveci,Yeliz Kasko Arıcı

doi:10.5194/aab-64-83-2021

Abstract

This research aimed to determine the effects of body weight, the body condition score (BCS), body measurements, birth type (single offspring or twin birth), birth weight and sex on the gestational length in sheep (). Karayaka sheep raised on a private farm were used in the study. Progeny yield characteristics in sheep were also determined (). Estrus was monitored daily using teaser rams from August to September 2016. According to our findings, the pregnancy rate, infertility rate, fecundity, and twin and single birth rates were 93.52 %, 6.48 %, 93.52 %, 14.62 % and 85.38 % respectively. The effect of age on the BCS in sheep at mating was found to be significant (): BCS decreased as age increased. It was determined that there was a positive association between the BCS and live weight during the mating period (). The chest circumference, front shin circumference and body length were found to be higher in sheep with a BCS at mating time (). The middle rump width was significantly affected by the BCS (). In this study, the lowest and highest gestational lengths were found to be 148.90 and 151.41 d respectively. The gestational length in sheep was not found to be affected by age, the BCS, body measurements, sex or birth type (); however, it was observed that the gestational lengths for male offspring and single offspring (non-multiple births) were longer. In addition, it was detected that the gestational length was different in sheep with a BCS . The time spent in the womb is important with respect to obtaining a healthy lamb. For profitable production, a BCS of between 2.5 and 4 is recommended in sheep. It is thought that the use of body condition scoring, which is easy information for the breeder to utilize, will have a positive effect on determining the bodily reserves of sheep and the reproductive efficiency as well as on obtaining a healthy lamb. More studies on the gestational length in sheep are required.

Highlights

Karayaka sheep are usually bred in the Black Sea region (Ordu, Giresun, Samsun, Sinop and Tokat provinces) and constitute 4.61 % of the total sheep population in Turkey (Turkish Statistical Institute, 2020)
Data were analysed for the factors affecting the gestational length of 111 pregnant ewes, according to the body condition score (BCS) values obtained during the mating period
It was determined that the chest circumference (CC), front shin circumference (FSC) and body length (BL) were larger in females with a BCS ≥ 4.5 during the mating period, and the effect of the BCS on the CC, FSC and BL was found to be significant (P < 0.01)

Summary

Introduction

Karayaka sheep are usually bred in the Black Sea region (Ordu, Giresun, Samsun, Sinop and Tokat provinces) and constitute 4.61 % of the total sheep population in Turkey (Turkish Statistical Institute, 2020). Karayaka sheep are a breed with a low milk and offspring yield, a fine tail and a coarse mixed fleece. They are known to have good-quality meat. In Karayaka sheep, the number of lambs at birth is 1.05 (Akcapınar et al, 2002). For this reason, it is beneficial for breeders to increase the fertility rate in this breed via various breeding methods (Cam et al, 2017). The selective breeding of twin animals in Karayaka sheep may increase the rate of twinning (Cam et al, 2017)

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