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Metabolism studies were carried out with 45 kg pigs to examine barley meal from the varieties Golden Promise, Maris Mink, Lami, Zephyr and Abacus, all with similar nitrogen (N) content, and barley meal from the variety Zephyr which had received four different levels of N fertilisation. There were no significant differences (P> 0.05) between varieties for the apparent digestibility coefficients of gross energy (GE) and proximate constituents. the least significant difference for GE and N being 0.025 and 0.089 of the respective means. The mean digestible energy (DE) and metabolisable energy (ME) values were 14.48 and 14.07 MJ/kg dry matter (DM). The mean apparent digestibility of N was 0.685. The apparent digestibility coefficients of G E and N of meal from the variety Zephyr increased with N content. The increase in DE value with N content could be attributed to the increase in N digestibility.

1978). Effect of dietary lysine levels on performance, nitrogen metabolism and plasma amino acid concentrations of lactating sows. ABSTRACTDuring lactation 30 sows were given a basal diet containing 0-39% lysine or the same diet supplemented with 0-1, 0-2, 0-3 or 0-4% Llysine. In addition a group of six sows was given a high protein/high lysine control diet containing 17% crude protein and 1-06% lysine. Piglet weight gain, sow milk yield, milk contents of total solids, protein, fat and energy and efficiencies of utilization of energy and protein for milk production increased progressively as dietary lysine levels were raised to 0-59 %. Sows receiving the lysine-supplemented diets had markedly higher efficiencies of conversion of dietary protein into milk protein and lower efficiencies of energy utilization than those given the high protein/high lysine control diet. Nitrogen retention and biological value of the dietary protein increased quadratically with increasing dietary lysine concentrations, reaching maximum values at 0-59% lysine. Apparent digestibilities of isoleucine, lysine, methionine, threonine and valine in the basal diet were closely correlated with digestibility of nitrogen. Plasma lysine concentrations remained depressed and relatively constant at low dietary levels of lysine, but increased sharply at 0-59 % dietary lysine coinciding with a marked drop in circulating concentrations of other essential amino acids.

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Three experiments, using in total 388 lambs, were completed in mid Canterbury. Weight losses resulting from different lengths of preslaughter fasting were measured on weaned lambs in March 1%9 and on unweaned lambs in November and December f%9. Results of the trials show:-1. That there appeared to be no difference between weaned and unweaned lambs in the starvation time needed to initiate carcass weight losses, and in the rate of carcass weight loss once it had started, for lambs down to 11 weeks old.2. That in all experiments more than t lb of carcass weight had been lost 24 hr after removal of lambs from pasture. This loss increased to 1.1-1.61b after 2 days' fasting.3. A major determinant of when carcass losses start after siarvation has begun seems to be the amount of stomach "fill" when lambs are removed from pasture.