Suckling behaviour and fertility in beef cows on pasture l. Suckling behaviour

Abstract

The suckling behaviour of one- to three-month-old calves, suckled by 66 Hereford, Simmentaler and Hereford X Simmentaler cows, was studied. The most common frequency of suckling in 24 h was 4, and the mean duration of each suckling event was 9.6 min. Suckling events were not evenly disributed throughout the 24-h period. Regardless of suckling frequency or days post partwn, the most common suckling perid was between 04:00 and 06:00. The lowest frequency of suckling recorded was in the period from midnight to dawn. The longest interval between two suckling events in all cows over the 24-h period always occurred before dawn and became longer as the calf grew older (P < 0.01). Once the mating seasonc ommencedt,h e onseto f oestrusw as positively conelated( P < 0.01) with the length of the longest inter-suckling period.

Die soginggedrag van een tot drie maande oue kalwers van 66 Hereford Simmentaler en Hereford X Simmentaler koeie is bestudeer. De mees algemene frekwensie van soging was 4 maal in 24 h, en die gemiddelde lengte van elke sogingperiode was 9.59 min. Sogings was nie eweredig oor 'n 24 h-periode versprei nie. Ongeag die frekwensie van soging en dae na kalwing, was die mees algemene sogingperiode tussen 04:00 en 06:00. Die minste sogingsperiodes is waargeneemt ussen middernag en ongeveer0 4:00. Die langste interval tussent wee sogingsperiodesb inne 'n 24hperiode het altyd voor 4:00 voorgekom en hierdie interval het langer geword met 'n loename in die ouderdom van die kalf (P < 0.01). Na aanvang van die dekseisoen was die aanvang van estrus positief gekorreleerd (P < 0.01) met die lengte van die langste interval tussen twee sogingsperiodes.

Keywords: Beef calves, beef cows, oestrus, suckling behaviour.