Four trials with a total of 1750 Perendale ewes were conducted to determine the effect of feeding lucerne on ovulation rate and lambing performance. Levels of up to 600 ppm coumestans in lucerne leaf, associated with fungal infection, depressed ovnlation rate and lambing by 34% and 14.6% respectively. In the absence of fungal infestation no coumestans were found and stage of regrowth had 110 effect on lambing performance. A negative linear relationship between coumestan ccntent of the diet (x) and ovulation rate (y) was determined (y = 1.382 -O.004x). Levels of coumestans as low as 25 ppm in the diet depressed the ovulation rate of ewes fed lucerne pellets for 35 days. The depression in ovulation rate of ewes fed a high (100 ppm) level of coumestans was overcome by treatment with pregnant mare's serum gonadotrophin. It is suggested that coumestans exert their effect by interference with the release of follicle stimulating hormone from the pituitary gland.

I. Thirty-three cross-bred lambs were given reconstituted dried whole cow's milk from I week of age at different levels of intake and at different frequencies of feeding. 2.Feeding frequency had no effect on live-weight gain, N retention or total body composition.3. Lambs given two feeds daily had significantly heavier abomasums than pair-fed lambs given six feeds daily. 4.The weights of fat, protein (N x 6 2 5 ) and water in the body were closely related to empty body weight; body composition (% of empty body) was not significantly affected by the level of milk intake or by the rate of growth.5 . Live-weight gain was closely related to energy intake (r = +o.gg) and to N retention (r = +o*g7). A live-weight gain of IOO g was associated with an intake of 51 I kcal and a N retention of 2.28 g N.Lambs and calves when reared with their dams are known to suckle at more frequent intervals than is usually practicable when they are hand-reared (Munro, 1955 ;. There is at present no evidence that feeding frequency has any marked effect on the growth rate or utilization of energy and nitrogen by the preruminant lamb or calf (Voelker & Jacobson, 1953), though studies with other animals suggest that both protein and fat metabolism may be affected (Cohn, 1962;Mochrie, 1964).The present paper describes three experiments, with milk-fed lambs, in which the effect of frequency of feeding over a wide range of energy and N intakes was studied. In the first experiment, lambs were bottle-fed two, three or six times daily, the intakes of energy being similar but controlled throughout. In the second experiment, lambs which were allowed to feed ad lib. twice daily were compared with pair-fed lambs given the same amount of milk in six feeds. In the third experiment, lambs were allowed to self-feed to appetite. The effect of feeding frequency on live-weight gain, N balance and total body composition was measured. EXPERIMENTALExperimental design Expt I . Comparison of two, three and six feeds daily. Fifteen male lambs were allotted at random to the dietary treatments. The experimental period of 4 weeks was divided into two equal periods (periods I and 2). The diet was given for a preliminary period of I week followed by a collection period of I week. The intake of feed was determined by the live weight of the lamb at the beginning of each preliminary period, and was * Paper no. 4 : Br.

Efficiency of utilisation of ewe's milk by the lamb was studied.The comparative slaughter method was used to determine gain or loss in body fat, protein, and energy. Of 24 crossbred lambs used, 12 comprised an initial slaughter group; the remaining 12 were given ewe's milk for 21 days at four different levels of energy intake ranging from sub-maintenance to ad libitum.Lambs fed at the lowest plane of nutrition mobilised body fat and were in negative energy balance; all the others were in positive energy balance. The mean digestibility of ewe's milk was 98.4% and was unaffected by the plane of nutrition. The mean metabolisability of the diet was 95.6% for lambs in positive energy balance and 91.8% for those in negative energy balance. The metabolisable energy requirement for zero energy gain was 145.2 kcal/kg o . 75 24 hr, and the efficiency of utilisation of metabolisable energy for maintenance and growth was 76.9%.

The palatability characteristics of carcasses of lambs grazed on either pure perennial ryegrass or piire lucerne were studied in three experiments. Consumer preferences were ascertained in two experiments with untrained members of the public who scored the meat for flavour, tenderness and juiciness. The type of pasture had no significant effect on the palatability characteristics examined but the shoulder joints were significantly more juicy than the legs. In a thirdexperiment, members of a trained taste panel were able to detect a significantly more intense flavour and odour from the casseroled twelfth rib chop of lucerne-grazed lambs than that from lambs grazed on perennial ryegrass.Since the results from the consumer acceptance tests and the trained taste panel were inconsistent, it is concluded that both methods of assessing palatability should be carried out concurrently in any evaluation of meat quality.