ALBERT

Description: SUMMARYIn a randomized block experiment, seventy-two Large White type weaner pigs (thirty-six hogs and thirty-six gilts) were individually and restrictedly fed to 200 lb live weight six diets (as wet mashes). Five of these diets contained high levels (85 % in the starter diets and 90 % in the finisher diets) of either maize, flaked maize, sorghum, wheat or barley. The sixth diet, which acted as the control diet for the experiment, was similar to the barley diet except that 25 % of weatings replaced a similar percentage of barley. A further three groups of six litter-mate hog pigs per group were used to measure the digestibility of these diets.For the starter diets the maize diet had the highest digestible energy content, for the finisher diets the highest values were for the wheat and sorghum diets which in turn were similar to each other. The digestible energy content of the flaked maize diet was higher than the contents of the barley and control diets but lower than the contents determined for the other three diets.Three of the pigs fed the sorghum diet developed leg weaknesses and this affected growth rate and food conversion efficiency. The symptoms suggested a pantothenic acid deficiency but the results of assays carried out on all the diets indicated that the condition was not necessarily due to a deficiency of this vitamin. Growth rates in the starter period (up to 115 lb) did not differ significantly between diets but food conversion for the maize and barley diets was significantly superior to that for the wheat and sorghum diets. In the finisher period growth rate and food conversion efficiency for the maize and wheat diets was significantly superior compared with that for the other four diets. Overall, from start to slaughter, the maize diet was significantly superior to the flaked maize, sorghum and control diets in both these parameters of performance. The energetic efficiencies of growth tended to be poorer for those diets with the better food conversion ratios, the best efficiency being for the control diet.Carcass length differences were not significant but backfat thickness and eye muscle area differences followed closely the pattern found for lean and fat content of the carcass. In this context the highest percentages of lean were found first in the control and, secondly, in the barley treatment carcasses. Some differences were found in the development of anatomical regions and tissues within these regions. In particular, and relative to the five other diets, there were in the control diet carcasses (1) higher percentages formed by the leg and shoulder and (2) a higher percentage of lean in the middle.

Description: SUMMARYIn an experiment involving sixty Large White pigs fed maize or barley based diets either ad libitum (AL) or to one of two restricted scales (R1 and R2), between 55 and 86 kg live weight, there were no significant cereal × feeding interactions for growth rate and the mean growth rates for the main effects were 0·62, 0·63, 0·81, 0·73 and 0·35 kg/day for the maize, barley, AL, R1 and R2 treatments respectively. There were no significant cereal × feeding treatment interactions for iodine number or calorific value of carcass backfat and the only significant differences between the main effects were those of lower iodine numbers for the barley (cf. maize) and the AT. (cf. R1) treatments.

Description: SUMMARYA factorially designed growth and carcass dissection experiment was made in which a low glucosinolate rapeseed meal (cv. Tower, TRSM) was compared with soya-bean meal (SBM) as the sole protein supplement in simple diets, containing barley and a vitamin and mineral supplement (to give 18 mg copper/kg air-dry diet) only, which were fed individually on a restricted scale of feeding to 72 pigs. The diets were of similar digestible energy (DE) content and were formulated to contain in each kg of air-dry matter 150, 170 and 190 g crude protein. In each crude-protein level the total lysine content was similar. Also experiments using 35 pigs were made to determine the ileal apparent digestibilities of amino acids in barley-based diets containing SBM, the low glucosinolate rapeseed meals Erglu (ERSM) and TRSM and a high glucosinolate British rapeseed meal (BRSM) and either 20 mg or 200 mg copper/kg air-dry diet.In the growth experiments there were no significant interactions for the variables considered. Pigs given TRSM diets, compared with those given SBM diets, had significantly poorer growth rates, conversion efficiencies and killing-out proportions but the proportions of lean and fat in carcasses and the backfat thicknesses (P2) were similar. There were no significant differences between protein levels in the killing-out proportions, the proportions of fat in carcasses and backfat thicknesses (P2) but pigs given diets containing 150 g, compared with 170 and 190 g, crude protein/kg air-dry diet had significantly lower growth rates and proportions of lean in the carcass and significantly poorer efficiencies of food conversion. The quantities of dietary crude protein used to produce units of live-weight gain, carcass weight and lean tissue increased progressively from the diets containing 150 to 170 to 190 g crude protein in each kg air-dry diet.In the ileal digestibility studies the results indicated that amino acids were of a lower digestibility in the rapeseed meal diets than in those based on SBM and that the copper content of the diet may have been important in this context.

Description: SUMMARYTwo growth and two metabolism experiments were made in which a low gluoosinate rapeseed meal (var. Tower; TRSM) was compared with soya-bean meal (SBM) as the sole protein-rich material in simple diets containing barley and a vitamin and mineral supplement only.In the first growth experiment 108 pigs were fed individually and restrictedly SBM and TRSM diets so that digestible energy (DE) and crude-protein intakes were similar. The DE used to promote a unit of growth or a unit of carcass weight was significantly less for the SBM, than for the TRSM, diet. In the second experiment 48 pigs were given, in groups of four, diets similar to those in Expt 1. There were no significant differences in growth rate or in serum thyroxine concentrations, but a significantly higher degree of thyroid hypertrophy was induced in pigs given the TRSM diet.The two metabolism experiments compared the same diets used in the first growth experiment. Apparent digestibility of dry matter, nitrogen and gross energy, and retention of nitrogen relative to intake, were significantly greater for the SBM diet than for the two RSM diets. The addition of synthetic lysine to the TRSM diet significantly improved the apparent digestibility and retention of nitrogen. Pooled DE values (MJ/kg dry matter) calculated for SBM, TRSM and barley were 13·72 (S.E. 0·318), 13·97 (S.E. 0·211) and 14·01 (S.E. 0·080) respectively.

Description: An experiment is described in which four pairs of individually fed identical twin calves were used to investigate the effects of castration at 1 and 7 months, on growth, efficiency of food utilization and carcass composition and conformation.The results indicate that up to 28 weeks of age the late-castrated animals wore superior in liveweight increase, width of head and efficiency with which they converted food to live weight. By slaughter time, at about 18 months, these differences, except width of head, had been eliminated.The carcasses from both treatments were very similar except that a slightly greater percentage of the total muscle occurred in the thoracic and abdominal muscles of the late-castrated animals than in the early-castrated ones. A statistically significant higher percentage of the total fat occurred as subcutaneous fat in the late-castrated animals than in the early-castrated ones.

Description: (1) In a 3×2 factorial experiment sixty Large White type weaner pigs (30 hogs and 30 gilts) were individually and restrictedly fed to 200 lb live weight, six diets (as wet mashes) containing 70 % of either maize, sorghum or barley, each cereal having been processed by either crimping or grinding prior to inclusion in its respective diet. A further two groups of six litter-mate hog pigs per group were used to measured the digestibility of and the nitrogen retention from these six diets at approximately 50, 110 and 190 lb live weight.2. Grinding gave significantly better digestibility than crimping, the ground diets having significantly higher digestible energy contents than the crimped. Between cereals the order of significant decreasing digestible energy content was from maize to sorghum to barley dietary treatments.3. There were no significant differences between cereals in nitrogen retention. Between processing treatments grinding, in terms of g. retained per kg live weight per day, gave a significantly higher value than crimping, at 107 lb live weight.

Description: Summary:Seventy-two (thirty-six hogs and thirty-six gilts) Large White type weaner pigs were individually and restrictedly fed four diets (as wet mashes) containing high levels (85% in the starter diets and 90% in the finisher diets) of either maize, sorghum, wheat or barley. Thirty-six pigs (nine per treatment) were slaughtered at 120 lb (54 kg approximately) live weight at the end of the period in which the starter diets were fed and the remaining thirty-six at 200 lb (90 kg approximately) live weight at the end of the period in which the finisher diets were fed.In the starter period the growth rates and food conversion efficiencies of the pigs fed the barley- and wheat-based diets were similar but taken together were slightly superior to those of the pigs fed the maize- and sorghum-based diets. Based on determined digestible energy values the caloric efficiency of live-weight growth was significantly better for the barley-based diet than for all other diets. At a slaughter weight of 120 lb the killing out percentage of the pigs fed the maize diet was significantly higher than that of the pigs fed the barley and wheat diets. Iodine numbers of inner and outer backfats were significantly higher in pigs fed maize than in those fed sorghum and wheat and in those fed barley compared with those fed wheat. There were no other differences in carcass measurements or in the percentages of lean, fat and bone dissected from the carcasses. However, the pigs fed barley had (1) significantly smaller middle regions and (2) as percentages of the total tissue within the body, significantly less fat in the middle region but significantly more fat in the shoulder region, than did any of the other pigs.In the finisher period the pigs fed the barley- and wheat-based diets grew significantly faster and converted their food and digestible energy of that food significantly more efficiently than did the pigs fed maize and sorghum. The caloric efficiency of live-weight gain was also significantly greater for the barley-fed pigs compared with those fed wheat. When slaughtered at 200 lb live weight, with the exception of backfat iodine numbers, where identical differences to those recorded at 120 lb were found, there were no significant differences in carcass measurements. On dissection the barley-fed pigs had significantly more lean and significantly less fat in the carcass than did any of the other pigs.

Description: SUMMARYIn an incomplete block 2x2x2 factorial experiment seventy-two Large White type pigs, after having been fed individually and identically up to 120 lb (54·5 kg) live weight, were fed from that weight up to 200 lb (90·9 kg) live weight maize or barley based diets (factor 1), with each diet having either a wide or a narrow calorie/protein/lysine (CPL) ratio (factor 2). The feeding was effected in individual feeders in a Danish type piggery (with six pigs per pen) with all diets offered as wet mashes and according to scales which gave two different calorie intakes (factor 3). There were, therefore, four different diets and eight different feeding treatments.

Description: SUMMARYIn a randomized block 3x2 factorial experiment 72 Large White type weaner pigs were individually and restrictedly fed, from 501b (22–7 kg) to approximately 1601b (72–7 kg) live weight, iso-nitrogenous (16% crude protein) maize-based diets (as wet mashes with 2:1 ratios of water to dry food) containing 0–15%, 0–22% or 0–29% tryptophan and either 0–85% or 0–97% lysine. Overall, for the period in its entirety and in the period from the start to 110 lb (50–0 kg) live weight, the diets containing 0–22% and 0–29% tryptophan gave a similar performance. Together they gave a significantly superior performance compared with that obtained from the diets containing 0–15 % tryptophan. Pigs fed the diets containing 0–85 % lysine converted their food better and grew faster than pigs fed the diets containing 0–97 % lysine. These differences were significant (P