Studies on the adaptation of cattle to the hydrolysis of biuret and on the response of rumen ammonia level to the introduction of 50, 100 or 150 g of feed-grade biuret showed that (1) the rate of ruminal adaptation to the hydrolysis of biuret increased to a maximum effective level of about 350 mg/24 h/100 ml within 10 days when a readily available energy source was fed, (2) a single dose of 50, 100 or 150 g/day of biuret was associated with a prolonged increase of rumen NH3 concentration. The magnitude of the increase was 8–9 mg/100 ml for every 50 g of added biuret, (3) adapted rumens retained their biuretolytic activity for several weeks, and responded to the re-introduction of biuret into the diet by increasing to a near maximum rate within 24–48 h.

A series of five field trials with cattle was carried out to study the comparative efficiency of utilization of urea and biuret in various maintenance and production nutritional situations. It was shown that in maintenance diets with energy intake above 8 Meal/head/day and where half of the nitrogen requirements of the animals was contributed by one of the two non-protein nitrogen (NPN) sources, biuret was utilized 30% more efficiently than urea. No difference in the degree of utilization of urea or biuret was apparent when the energy was reduced to 6·7 Meal/head/day. On the other hand, a high intake of nitrogen in production rations had a masking effect on the nitrogen contribution of the NPN sources and no significant differences in bodyweight gain were recorded.

Ramularia beticola was prevalent in sugar-beet seed crops in Oxfordshire, Gloucestershire and Lincolnshire in July each year from 1966 to 1971, and defoliated some crops prematurely. It was scarce in Bedfordshire, Huntingdonshire and Essex, and this distribution could not be related to method of growing the crop or density of plant stand. A method is described for assessing leaf spot incidence in beet seed crops after bolting is complete. Fungicide sprays delayed disease development by ca. 2½ weeks.

A total of 580 Friesian cows from four dairy farms selected at random were grouped by teat shape. The incidence of teat cup crawl was recorded at the time of afternoon milking.

Teat cup crawl was significantly higher (27·4%) in the cows with cylindrical shape teats than in cows with funnel shape teats (8·1%).

Milk yield was significantly higher in the cows with funnel shape teats than in cows with cylindrical shape teats. There was significant reduction in milk yield due to teat cup crawl in both groups of cows, the reduction in milk yield being higher in the cows with cylindrical shape teats.

A general model of lysine deposition in cereal grains is presented. By inserting into the model values for the lysine contents of various individual protein fractions, equations have been derived which relate total lysine content to total nitrogen. The equation for barley has been used to predict the likely variation in lysine content for this species and the results are compared with published data.