The yield of colostrum and colostral gammaglobulins in beef cows and the absorption of colostral gammaglobulins by beef calves.

The details of a small study on the volume of colostrum and colostral gammaglobulins produced by beef cows at the first milking immediately after calving and the serum concentrations of passively acquired colostral gammaglobulins attained by beef calves are reported. The mean volume of colostrum and colostral gammaglobulins produced were 2990 +/- 2100 (SD) mL and 314.75 +/- 211.8 (SD) g respectively. The mean serum concentrations of passively acquired colostral gammaglobulins were 29.9 +/- 10.1 (SD) ZST units (n = 40, Ranch A) and 19.2 +/- 7.5 (SD) ZST units (n = 42, Ranch B). The main reason for this difference appeared to be nutritional; the cows on ranch B being in much poorer condition and almost certainly producing less colostrum than those on ranch A.