LIFETIME REPRODUCTIVE EFFICIENCY OF FIRST-CROSS BEEF COWS UNDER CONTRASTING ENVIRONMENTS

The Lifetime Reproductive Performance of Cows in a South Australian Beef Herd

In comparison with the three calves produced per breeding cow in a herd of the same breed in Queensland (Donaldson, 1962), the South Australian cows produced slightly more progeny in only five and a half years compared to eight years in Queensland. The Roseworthy cows were more productive over a shorter period because they were able to'be bred a year earlier and had shorter calving intervals. D...

Beef Cross Breeding of Dairy and Beef Cows

Reproductive Efficiency of Cows of Different Sizes

The effect of cow size on reproduction has become of in, respectively. The hip heights of the small, medium greater concern in recent years as a result of marked and large frame-size bulls used were 53, 55 and 57.5 in, increases in cow size in both purebred and commercial respectively, at 2 yr of age. The bulls were selected from herds and the extremely large effect of fertility on the within t...

Treatments to Optimize the Use of Artificial Insemination and Reproductive Efficiency in Beef Cattle under Tropical Environments

Bos indicus cattle, the preferred genetic group in tropical climates, are characterized by having a lower reproductive efficiency than Bos taurus. The reasons for the poorer reproductive efficiency of the Bos indicus cows include longer lengths of gestation and postpartum anestrus, a short length of estrous behavior with a high incidence of estrus occurring during the dark hours, and puberty at...

Evaluation of biological efficiency of free-grazing beef cows under semidesert conditions.

Effects of cow BW, hip height, and estimated genetic potentials (EBV) for weaning weight direct and milk on cow productivity, fecal OM output, OM intake, and efficiency (kilograms of calf BW/kilogram of OM intake by the cow) were evaluated with 44 free-grazing crossbred cows under semidesert conditions. Calf BW were measured during early, mid-, and late lactation. Data were collected in four pe...