Effects Of Inbreeding On Important Economic Traits Of Inner Mongolia Cashmere Goats

The objective of the present study was to evaluate the level of inbreeding and its effects on important economic traits in Inner Mongolia cashmere goats. Data of pedigree and performance records for 23 year (1990-2012), collected from the breeding flock of Inner Mongolia cashmere goats maintained at the Arbas stock farm, were used in the analyses. The traits studied were cashmere weight, fiber length, fiber diameter, gestation length, litter size at birth, birth weight, weaning weight, yearling weight and adult weight. To investigate the effect of inbreeding on phenotypic values, genetic parameters and estimated breeding values, two different models including no measure of inbreeding and individual inbreeding coefficients F (linear and quadratic) were take into account. The results suggest that the average inbreeding coefficient for the whole population was 4.01%, ranging from 0 to 35.94%. The mean rate of inbreeding was 0.32% per year for all animals. Both cashmere weight and fiber length increased at low levels of inbreeding, but decreased when levels of inbreeding were higher than 12.5% and 4.4%, respectively, while FD became thinner with any increase of F. Gestation length and litter size at birth were not significantly affected by inbreeding. Significant quadratic and linear regression coefficient of 0.0003 and -0.0021,0.0116 and -0.1557 were investigated for birth weight and adult weight, respectively. Inbreeding was also noted to significantly decrease weaning weight and yearling weight by 0.0231kg and 0.0353kg linearly, as 1% of F increased. Moreover, the estimation of genetic parameters and breeding values for the studied characters was essentially unaffected by inclusion of F in the model.