ALBERT

Description: SUMMARYTwenty-four Friesian bull calves purchased at 10 weeks old were reared in three groups to slaughter at 420 kg live weight. One group (BB) was fed on a barley-concentrate diet to grow rapidly at 1·41 kg/day, a second (GG) was fed on dried grass cubes to grow slowly at 0·97 kg/day and the other (BG) was fed to grow rapidly to a live weight of 250 kg and thereafter at a slow rate, overall 1–20 kg/day.Efficiency of food conversion, energetic efficiency and efficiency of dissectible muscle production were best for BB animals, followed by BG and then GG. Changes in carcass composition mainly resulted from differential fat deposition, and bone/ muscle development was allometric in relation to fat-free empty body mass. The development of certain characteristics, the head, depth of forequarter, pelvic length and tibia length followed a time scale and may have reflected the priority for nutrients of some entire male characteristics irrespective of body size.In addition to being most efficient, the fastest growing bulls yielded carcasses with sufficient fat deposition to meet grading requirements, whereas both the slower growing groups of bulls were penalized in this respect.

Description: SummaryA total of 146 nulliparous gilts at two centres were assigned to lactation lengths of 10, 25 or 40 days and maintained on the same weaning regime for up to five parities.The interval between weaning and conception tended to be shorter for the 40-day treatment with little difference between the 10- and 25-day treatments. The data from all parities were pooled on the basis of an assumed herd structure giving the number of litters produced per sow per year aa 2·63, 2·37 and 2·18 for the 10-, 25- and 40-day treatments respectively.The number of pigs born alive per litter remained more or less static with successive parities on the 10-day treatment but increased on the 40-day treatment with differences between treatment s reaching or approaching significance in parities 4 and 5. Although this trend was reflected in the number of pigs weane d per litter, the differences between lactation treatments were non-significant as a result of higher post-natal mortality in the larger litters of the longer lactating sows.Consequently sows on the 10-day treatment reared the highest number of pigs per year, 22·4 compared with 20·2 and 19·8 for 25- and 40-day lactations respectively.Data are also presented on changes in sow live weight.A high culling rate and an extended interval betwee n weaning and conception were experienced at one centre in parity 1. The possible reasons and effect on subsequent litter size are discussed.

Description: SUMMARYIn a factorial experiment the effect of two protein intakes and three patterns of feeding in the second pregnancy of 48 Large White x Wessex Saddleback sows was examined. The high protein (HP) diet (19·5% crude protein) contained 15% white fish meal. The low protein (LP) diet (10·5% crude protein) contained cereal protein only. Nutrient components of the diets differed in protein only. The pattern treatments involved allowances of 1·8 kg (L), 2·7 kg (C) and 3·6 kg (H) per day, the three pregnancy patterns being HL, C and LH with the changeovers made from the 49th to the 63rd day post coitum (p.c). Sows on the three pattern treatments received the same total amount of feed from 0–112 days p.c. and were treated alike at farrowing and during lactation.Fertility and parturition results were similar for all treatments, but the number of piglets alive after birth (when weighed) was least for LP sows on the HL pattern. At 3 weeks of age the size and weight of litters on HP sows were significantly greater than those on LP sows (P 〈 0·05 and 〈 0·001 respectively). More piglets were weaned by HP sows than LP sows (P 〈 0·05). HP sows gained more weight in pregnancy (P 〈 0·001) which was slightly longer, and lost more weight in lactation (P 〈 0·05) than LP sows.The HL pattern of feeding was associated with smaller live weight gains in pregnancy than the LH pattern (P 〈 0·001) and the total birth weight of HL litters was lighter than LH (P 〈 0·05), mean piglet weights being similar. Lactation performance was unaffected by pattern treatment.The main conclusion is that a low intake, particularly during the latter half of pregnancy, of protein which is of vegetable origin, is associated with decreased viability of the piglets at birth and in early suckling life, and with lower capacity of the sows for milk production.