Estimation of Genetic Parameters for Deviation in Age at Market Weight and Deviation in Weight at Market Age in Menz Sheep

IF 1.9 3区农林科学 Q2 AGRICULTURE, DAIRY & ANIMAL SCIENCE

Journal of Animal Breeding and Genetics Pub Date : 2025-10-30 DOI:10.1111/jbg.70023

Zeleke Tesema Wondie, Shanbel Besufkad, Aschalew Abebe, Shenkute Goshme, Asfaw Bisrat, Ayele Abebe, Alemnew Araya, Tesfaye Zewdie, Chekol Demis, Liuelseged Alemayehu, Erdachew Yitagesu, Tefera Mekonnen, Firdawok Ayele, Derb Aydefruhim, Tesfa Getachew, Enyew Alemnew, Solomon Gizaw, Tesfaye Getachew, Berhanu Belay, Barbara Rischkowsky, Yu Jiang, Aynalem Haile

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引用次数: 0

Abstract

Reducing the number of days from birth to slaughter is one strategy to improve animal feed and environmental efficiency. The export market use yearling sheep weighing 22–30 kg and usually purchases from large and small-scale traders at an early age (lambs weighing ≥ 15 kg) for mutton production. Hence, this study aimed to derive a new trait phenotype, which helps to reduce sheep market age without adverse effects on the market weight of Menz sheep and to evaluate the extent of exploitable genetic variation in this new trait. To this end, 11,258 lambs weighing ≥ 15 kg between 66 and 395 days of age were considered in this study. Co (variance) components and heritability estimates for novel traits were estimated using the average information restricted maximum likelihood method in WOMBAT fitting the animal model. The best-fitted model was selected from six models based on likelihood ratio test and Akaike's information criterion. The days-to-market weight of 16.3% of the animals was shorter by 48.2 days (with an estimated breeding value of −26.2 days) compared to the mean of the contemporary groups. The market weight of 15.5% of the animals was higher by 1.73 kg compared to the mean of the contemporary groups. There was a phenotypic variability of deviation in age at market weight (DAMW) and deviation in weight at market age (DWMA) for the sheep population in Molalie village compared to other villages. Likewise, the genetic standard deviation for DAMW and DWMA was 25 days and 0.79 kg, respectively. Based on the best-fitted model, the direct heritability estimate for DAMW and DWMA was 0.65 and 0.57, respectively. In addition, the maternal genetic effect explains 28% of the phenotypic variation in DAMW and 26% of the phenotypic variation in DWMA. The DAMW of Menz sheep in Dargegn and Molalie villages decreased significantly by 2.113 and 1.192 days year⁻¹, respectively. The observed additive genetic variance for DAMW suggests further scope for genetic improvement in the flock to reduce the days-to-market weight of Menz sheep. Including this novel trait in a breeding objective could shorten days to market weight without necessarily reducing the genetic merit of the live weight included in the breeding objective.

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门兹羊市售体重年龄偏差和市售体重偏差遗传参数的估计。

减少从出生到屠宰的天数是改善动物饲料和环境效率的一种策略。出口市场使用体重22-30公斤的一岁羊，通常从大型和小规模贸易商那里购买幼龄羊（体重≥15公斤的羔羊）用于羊肉生产。因此，本研究旨在获得一种新的性状表型，该表型有助于降低羊的市场年龄，而不会对门兹羊的市场体重产生不利影响，并评估该新性状的可利用遗传变异程度。为此，本研究选取了11,258只66 ~ 395日龄体重≥15 kg的羔羊。利用平均信息限制最大似然法在袋熊中拟合动物模型，估计新性状的Co（方差）分量和遗传力。根据似然比检验和赤池信息准则从6个模型中选出最优拟合模型。与同时代群体的平均体重相比，16.3%的动物到市场的体重缩短了48.2天（估计繁殖值为-26.2天）。15.5%的动物的市场体重比同时代群体的平均体重高出1.73 kg。与其他村庄相比，Molalie村绵羊种群在市重年龄偏差（DAMW）和市重年龄偏差（DWMA）方面存在表型变异。DAMW和DWMA的遗传标准差分别为25 d和0.79 kg。基于最佳拟合模型，DAMW和DWMA的直接遗传力估计分别为0.65和0.57。此外，母系遗传效应解释了DAMW中28%的表型变异和DWMA中26%的表型变异。达尔根村和Molalie村Menz羊的平均生存期（DAMW）分别显著降低了2.113天和1.192天。观察到的DAMW的加性遗传变异表明，在羊群中有进一步的遗传改进空间，以降低门兹羊的日数到市场重量。在育种目标中包括这种新性状可以缩短到上市重量的天数，而不一定会降低育种目标中包括的活重的遗传优点。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Animal Breeding and Genetics 农林科学-奶制品与动物科学

CiteScore

5.20

自引率

3.80%

发文量

审稿时长

12-24 weeks

期刊介绍： The Journal of Animal Breeding and Genetics publishes original articles by international scientists on genomic selection, and any other topic related to breeding programmes, selection, quantitative genetic, genomics, diversity and evolution of domestic animals. Researchers, teachers, and the animal breeding industry will find the reports of interest. Book reviews appear in many issues.