Last update: November 22, 2010 12:33:05 PM E-mail Print

 

An evaluation of production and reproduction of Boer goats

I. The influence of age of the doe on reproductive performance

 

P. G. Marais1 * & J. C.  Scheltema2


1Grootfontein Agricultural Development Institute, Private Bag X529, Middelburg, 5900,  Eastern Cape,  South Africa

 2PO Box 34253, Newton Park, Port Elizabeth, 6055, Eastern Cape, South Africa

 


Reproduction is the most important characteristic of farm animals. The influence of dam-age is, therefore, an important consideration in the optimum flock structure and reproduction rate. Hence, the purpose of this study was to provide information on age specific reproduction and viability rate of Boer goats. Data collected from 1985 does and 3336 kids from Adelaide experimental farm during the period 1978 to 1989 were used to investigate the influence of age of dam on reproductive performance. The significant curvilinear regression line indicated that body weight at mating first increased and then declined with age of the does. The does reached the maximum body weight at 5.5 years of age. The number of does kidded/does mated exhibited a significant curvilinear relationship. The relative values exhibited a rising tendency up to the age of 3.5 years, after which they remained constant up to 4.5 years, where after they declined. The maximum number of offspring born per doe mated occurred at 4.5 years of age. The number of kids born per doe kidding increased curvilinearly up to 6.5 years . The incidence of  births was 9.6%, for single kids, 52.8% for twins, 34.8% for triplets and 2.9% for quadruplets. The mortality rate for lambs born alive was  20.1%, 13.7%,  22.1% and 19.8% for singles, twins, triplets and quadruplets. The average mortality rate was 17.7%. Results obtained suggest that selection for multiple births other than twins is not always desirable because of the relatively high mortality rate.