Two groups of five lambs were removed from their dams within 48 hr of birth and artificially reared to a slaughter weight of approximately 32 kg on a milk replacer given cold, hay and concentrates. Voluntary intake of the feeds was recorded together with growth rates and carcass composition of the lambs.

The two groups of lambs were slaughtered at 58 or 67 days of age with growth rates of 459 and 433 g/day, respectively. The mean milk replacer dry matter consumed per lamb was 34·9 kg and 39·3 kg and concentrate dry matter intakes were 3·1 kg and 4·1 kg. Intakes of hay were negligible. Food conversion efficiencies were 0·70 and 0·67 kg of live-weight gain per kg of dry matter consumed. The mean carcass weights were 18·1 kg and 19·5 kg with mean muscle, bone and fat contents of 48·7%, 16·2% and 35·1 % for lambs slaughtered at 58 days and 48·0%, 14·7% and 37·2% for those slaughtered at 67 days.

Body temperature and respiratory rate were investigated during the hottest months of the year in five docked and five undocked fattailed Awassi rams, together with the effect of month and docking on these physiological variables.

Month had significant effects on both variables in the two groups. Diurnal variation in rectal temperature was significant in both groups.

Docked rams maintained significantly lower rectal temperatures and respiratory rates than their controls.

Haemoglobin types of two Indian breeds of sheep were related to ram and ewe fertility and lamb mortality. Rams with Hb B type had a significantly higher number of lambs born to ewes mated to them. Ewe fertility and lamb mortality were better, but not significantly so, in animals with Hb B type.

Animal Production, Volume 13, part 1, pp. 193–195

A note on the haem pigment concentration of lamb as influenced by age and sex

by D. A. Ledward And W. R. Shorthose

C.S.I.R.O. Division of Food Preservation, Meat Research Laboratory, P.O. Box 12, Cannon Hill, Queensland, 4170, Australia.

In this article, ‘The factor used to convert acid haematin to total haem pigment concentration should be 17·7 not 35·4. Thus all the haem pigment concentrations quoted are double their true values. This error in the absolute concentrations of both myoglobin and haemoglobin does not affect the statistical analysis of the results and the conclusions reached regarding the influence of age and sex on myoglobin concentration.’