淘料视频

Citation

Thesis Title
Assistance at parturition in primiparous, two-year-old, Angus heifers and the effect of liveweight gain of heifers in early pregnancy on birth weight of the calf

Read article at Massey Research Online:

Ms Hickson investigated factors affecting calving difficulty in two-year-old, first-calving beef heifers, with particular focus on birth weight of the calves. A simulation showed that except at very high rates (>89%) of assistance at calving, it was more profitable to calve heifers at two instead of three years of age. Her industry survey revealed difficult birth was implicated in half of the calf deaths that occurred between birth and marking. Rate of assistance at calving increased with increasing birth weight of the calf and decreasing live weight of heifers but was not affected by body dimensions of the calf or maternal plasma oestrone sulphate concentration. Varying the rate of live weight gain of heifers during the first trimester of pregnancy did not consistently affect the birth weight of their calves and had only minor affects on milk yield in first lactation and did not affect subsequent breeding of the heifers.

Supervisors
Professor Stephen Morris
Professor Paul Kenyon
Professor Nicolas Lopez-Villalobos