Drought feeding studies with cattle. 8. Early weaning of beef calves

Abstract

Two experiments on the early weaning of beef calves as a drought relief measure are described. As the calves had been suckling dams used in studies on drought feeding, they were poorly grown at weaning. The duration of both experiments was 6 weeks.
In one experiment, 19 Hereford calves were weaned at a mean age of 62 days and mean body-weight of 94 lb on to a ration of equal parts of lucerne chaff and crushed sorghum gain ad lib. The mean body-weight gain and mean feed intake were 1·1 and 5 · 07 lb per head per day respectively. There were no deaths.
The calves used in the second experiment had been suckling dams that had received restricted all-grain rations containing negligible carotene for 24 weeks in late pregnancy and early lactation. The calves were weaned on to a ration of crushed sorghum grain ad lib. when their mean age was 70 days and mean body-weight 106 lb. The average gain in body-weight was 0·48 lb per head per day, while mean grain consumption was 3·27 lb per head per day. Two deaths occurred. These two calves had low liver vitamin A reserves, and some of the other calves showed nyctalopia and low plasma vitamin A levels at the end of the experiment.
Determination of blood haemoglobin, packed cell volume, glucose, inorganic phosphate; and serum calcium, magnesium, total protein, albumin and globulin were made on calves at the beginning and end of the second experiment. Although there were some differences between initial and final values in some constituents, they were comparable to those obtained in Hereford calves of similar age suckling dams that were grazing the pastures at the Animal Husbandry Research Farm, Rocklea.