Suckling behaviour and fertility in beef cows on pasture 2. Influence of twelve-hour calf separation on interval to first oestrus after onset of mating period

Abstract

For two weeks prior to the start of the breeding season, the suckling behaviour of  beef calves, separated from their dams for 12 h out of 24, was investigated.Fifty-six per cent of the 44 cows which were separated from their calves from 18:00 to 06:00 (day-sucklers)exhibited oestrus within 30 days of the start of the breeding season, compared to 22% of the group separated from 06:00 to 18:00 (P < 0.01). It was concluded that not only the suppression of suckling may be involved in the onset of ovarian activity.The specific time period during the 24 h when suckling is prohibitedmay also playa role.

Vir twee weke voor die aanvang van die jaarlikse teelseisoen,is die  sogingsgedragvan vleisbeeskalwerswat vir 12 h uit elke 24 h van hul moeders geskei was, bestudeer. Ses-en-vyftigpersent van die 44 koeie wat tussen 18:00 en
06:00 (dag-sogend) van hul kalwers geskei was, het binne 30 dae na aanvang van die teelseisoen tekens van hitte getoon, in vergelykingmet slegs 22% van die groep wat tussen 06:00 en 18:00 (nag-sogend)geskei was. Die aanvang van eierstokaktiwiteitword nie slegs deur die beperking van soging be'invloednie. Die spesifieke periode gedurende 'n 24h-tydperk,waarin die beperkingplaasvind,mag ook 'n rol speel.