Saber Jelokhani-niaraki; Sholeh Ghorbani; Saeid Esmaeilkhanian
Volume 23, Issue 3 , September 2021, , Pages 313-324
Abstract
Monitoring the inbreeding rate of native chickens in breeding stations is of significant importance because of planned matings and lack of gene flow in the population. This study was undertaken to estimate the inbreeding coefficient, investigate the trend of inbreeding changes and evaluate the effects ...
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Monitoring the inbreeding rate of native chickens in breeding stations is of significant importance because of planned matings and lack of gene flow in the population. This study was undertaken to estimate the inbreeding coefficient, investigate the trend of inbreeding changes and evaluate the effects of inbreeding depression on the economic traits in Isfahan improved native chicken population. The studied traits were body weight, age at sexual maturity, weight at sexual maturity, egg number, mean egg weight and egg weight at first day. In the present study, data of 97272 birds recorded during 21 generations were included. In order to estimate the inbreeding coefficient of each bird and the effect of inbreeding on the traits, CFC and WOMBAT software were used, respectively. Pedigree analysis indicated that 79.48 percent of population were inbred. The estimated average individual and maternal inbreeding coefficients were 4.3 and 3.5 percent, respectively. According to results, for every one percent increase in inbreeding, rate of inbreeding depression for the traits including the body weight in 1 day, 8 weeks and 12 weeks, age at sexual maturity, weight at sexual maturity, egg number, average weight of eggs and egg weight at first day was -0.008, -2.52, -3.51, 0.23, -3/97, -0.13, 0/02 and 0.06, respectively. Based on the results of the present study, although in closed populations under genetic selection, the absence of inbred bird is almost impossible, but, the reduction of inbreeding can be achieved by controlling the matings, which prevents the adverse effects of inbreeding in the population.
Karim Nobari; Abdol-Halim Kor; Abdolhakim Toghdory; Saber Jelokhani-niaraki
Volume 21, Issue 4 , January 2020, , Pages 451-459
Abstract
The objective of this study was to consider biometric indices for distinguishing the difference between the Thoroughbred and the Turkoman horse breeds. Body conformation traits of 23 stallions and 23 mares of Thoroughbred and 26 stallions and 33 mares of Turkoman at the ages of two, three and ...
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The objective of this study was to consider biometric indices for distinguishing the difference between the Thoroughbred and the Turkoman horse breeds. Body conformation traits of 23 stallions and 23 mares of Thoroughbred and 26 stallions and 33 mares of Turkoman at the ages of two, three and four years , were measured for calculating of 12 indices. Then, the data were analyzed as a factorial of 2×2×3 undercompletely randomized design using R software. The considered factors included: breed (Turkoman and Thorughbred), sex (mare and stallion) and age (two, three and four years of age). This study showed that indices of withers to body length (P<0.05), metacarpus circumference to its length (P<0.01) and metatarsus circumference to its length in Thoroughbred breed were greater than Turkoman breed and index of head side neck width to withers height ratio in Turkoman breed was significantly (P<0.05) پ greater than Thoroughbred breed. Age and sex had a significant effect on three different investigated indices. According to the significant effect of breed on some biometric indices, the indices in respect to sex and age can be used for breed identification.