Die invloed van omgewingsfaktore op speeneienskappe van Afrikanerkalwers

Abstract

Data from  1142 Afrikaner calves from the herd of stud Afrikaner cattle at the Glen Agricultural Research lnstitute were used. The calves were the progeny of'27 sires and the data collected over a period of 25 years. According to a least square analysis of variance, yeius, sires. month of birth, sex of calf and mas of dam before calving had statistically significant effects on the weaning traits. Large variations for mas at birth, at 90 <iays and at weaning and for increase in mass to 90 days and to wearung occurred between years and between sires. Sex of calf was the most significant source of variation studied, bull calves being 8,28/oheavter at birth, 8,11% at 90 days and 10,64 % at weaning. There was an increase rn weaning traits with increase in mass of dam and although no1 significant, with the agcl parity of the dam. The weaning traits showed an inverse relationship with adrancing summer caiving season except the birth mass which showed an increase.

Gegewensv an 1 142 Af r ikanerkalwers,d ie nageslagv an 27 bul le, is oor 'n per iode van 25 jaar versamel .D ie kalwers rs van dic stoet Afrikanerkudde ran die Glen Landbounavorsingsinstituul afkomstig. Volgens 'n kleinste kwadrate variansie-analiseh et jare, vaders. maand van geboorte, geslagv an kalf en massav an moeder voor kalwing 'n statistiesb etekenisvollee ffek op die speeneienskappev an dre kalwers gehad. Groot var iasiest ussenj are en tussenv adersh et ten opsigte van die geboor te- ,9 0-daee n speenmassae n die toenamesi n massa tot 90dae en tot speen voorgekom. Geslag het die grootste enkele invloed gehad. Bulle het by geboorte 838% meer massa gehad as die verse,b y 9Odae 8,71% me( ' r en by speen 10,64%m eer . Die speeneienskappvea n die kalwersh er toegeneemm er verhoogdem assa van die moers en alhoewel nie stat ist iesb etekenrsvol ,m et die ouderdom/produksiestatusv an die moeder . Die speeneienskappeb,e halwe die geboor temassaw at toegeneemh et , het afgeneemn amated ie kal fseisoeng evorder het .