Published online by Cambridge University Press: 27 March 2009
The serum protein-bound iodine concentration in the blood of beef steers varied between animals and was not correlated with the daily gain during the fattening period. The data, however, are insufficient to arrive at a definite conclusion.
The average erythrocyte counts of the blood were 7·86 (range: 5·89–8·75), 8·59 (range: 6·55–10·15), and 8·54 (range: 5·23–9·62) million per mm.3 for steers of 14, 26 and 38 months of age. The difference between the counts of the yearlings and that of the other age groups was statistically significant. The red cell fraction increased with live weight over the range 700–1230 lb. Although a significant (P < 0·01) correlation was found between the number of erythrocytes in the blood and the daily gain of the steers, the erythrocyte count cannot be employed to predict the possible gaining ability of single beef animals.
The haemoglobin content of the blood was found to be 14·02 (range: 9·8–17·4) in the case of the yearlings, 14·68 (range: 11·8–18·5)and 14·61 (range: 7·95–16·85) g./100 ml. blood in the case of the 2-year-olds and 3-year-olds respectively. These differences between age groups were not significant.
A correlation of 0·31 was found between the haemoglobin content and live weight of steers within the weight range of 600–1230 lb. The data suggest that for every 100% increase in weight, the haemoglobin in the blood increased by 17%. No correlation was found between the haemoglobin content and the rate of gain of the steers.