Factors associated with differences in carcass conformation were studied in three experiments involving 85 pairs of lambs, half of which had been selected as having blocky conformation and half leggy conformation. Pairs of carcasses were matched for carcass weight and age at slaughter.The blocky carcasses contained more fat and less red meat and bone than the leggy carcasses. They also had a higher proportion of the fatter cuts (loin, ribs, and flap) and a lower proportion of the leaner cuts such as the leg. A taste panel found the palatability characteristics of leg meat from both types of carcasses acceptable and did not differentiate between them. The differences in conformation strongly influenced the export grading of the carcasses, the blocky carcasses grading predominantly Prime Down Cross and the leggy carcasses mainly Prime Crossbred and Y.South down sires produced the blockiest carcasses and the other breeds studied produced the leggiest carcasses. Within-breed variation was also noted in one experiment where conformation differences were less extreme. The leggy carcasses came from animals that had heavier liveweights at slaughter than the blocky animals, although the hot carcass weights of both were the same.The results are discussed in relation to the New Zealand meat industry. The conclusion is reached that the blocky carcasses have no superiority in terms of meat content or proportion of high-priced cuts, and that in future more emphasis should be placed on economic characteristics and less on conformation in breeding and crossbreeding programmes.

No abstract

An intake of spray-dried whole-ll)ilk powder equivalent to 2% of body weight was maintained in calves during the first 12 weeks of life when the powder was supplemented with iron, copper, and magnesium.Intakes relative to body weight declined after the age of 12 weeks when fortification with iron and copper ceased. Gradual increases in the dry-matter content of milk to compensate for the decline in abomasal capacity relative to body weight did not enhance intake between the age of 12 and 16 weeks.Supplementation of spray-dried whole-milk powder with iron and copper at levels of 46.7 and 5.1 mg/kg respectively maintained blood haemoglobin concentrations. Fortification of the powder with 0.25 g of magnesium per kg did not prevent, but appeared to delay, the onset of progressive hypomagnesaemia.An increase in the apparent digestibility of fat and a decrease in the digestibility of lactose and ash were noted with advancing age. Reconstitution rate did not affect the digestibility of milk nutrients up to the age of 16 weeks.

No abstract