Vrugbaarheid van vleisbeeste op die Soutpan beesplaas

Author: G. Marincowitz
Year: 1978
Issue: 2
Volume: 8
Page: 119 - 123

The conception rates of 495 lactating cows and 99 replacement heifers were compared over a 3-year period on an extensive cattle ranch in the sour mixed bushveld. A summer breeding season and controlled selective grazing were applied. A protein-rich dicalciumphosphate lick was freely available throughout the year. The breeding herd consisted of Simmenthaler and Africander crossbred cows and heifers which were mated with purebred Africander and Simmenthaler bulls in a criss-crosss system.The reconception rate of lactating cows (88%) was slightly higher than that of the 2-year old heifers (86%). Differences noted between the Africander and Simmenthaler crosses were: -, Africander cross cows and heifers exhibited a6% and 8% lower conception rate, respectively than those of the Simmenthaler crosses; conception rate of Africander crosses improved from the 2-year old heifers to reach a maxium at 5 years of age whilst Simmenthaler crosses maintained a higher and relatively stable conception rate throughout their reproductive lives; in both crosses cows which calved early in the season exhibited the highest reconception rate, but Africander crosses failed to achieve the same level of reconception as the Simmenthaler crosses, particularly cows which calved later in the season; replacement Africander cross heifers calved over a longer period during the season, whilst older Africander cows tended to calve later in the season.

Keywords: Cattle, fertility
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