Responses to variations in dietary energy intakes by growing pigs 3. Effect of level of intake of diets of differing protein and fat content on the performance of growing pigs

1972 ◽  
Vol 15 (2) ◽  
pp. 127-137 ◽  
Author(s):  
J. L. Davies ◽  
I. A. M. Lucas

SUMMARYThree diets were given separately, each at four levels of digestible energy (DE) intake, to gilts, castrates and boars growing from 21 to 92 kg live weight. The energy levels were those suggested by the Agricultural Research Council, compared with a 5% increase or 10% or 20% decreases in daily allowance. One diet (ME 18) had 3·0 Meal DE/kg and 18·2% crude protein; the other two (HE 16 and HE 19) had 3·26 Meal DE/kg and 16·1% or 19·3% crude protein.They were given unchanged throughout the experiment. Responses to change in daily DE intake were not affected by sex or diet, except in shoulder fat thickness. Feed eaten per kg gain did not vary by more than 4% over the intake levels investigated, and no difference was significant. On average, each reduction in daily intake below the ARC+5% allowance led to an increase of 1·2 percentage units of carcass lean and a decrease of 1·3 percentage units of carcass fat.In comparison with HE 16, the higher protein diet HE 19 gave improved feed conversion efficiency and growth rate, particularly in gilts. It did not cause significant changes in carcass measurements. In comparison with ME 18, HE 19 gave more efficient conversion of DE to weight gain, and faster growth.Boars required less feed per kg gain and had faster growth rates and leaner carcasses than gilts, which were superior to castrates. There was a high incidence of unpleasant odour in fat from boars, but some was also detected in that from gilts and castrates.

1972 ◽  
Vol 15 (2) ◽  
pp. 117-125 ◽  
Author(s):  
J. L. Davies ◽  
I. A. M. Lucas

SUMMARYAllowances of about 1·4M, 1·8M, 2·2M, 2·6M, 3·OM, and 3·4M (M = feed required for maintenance) were compared for pigs growing over the live-weight ranges 20·40, 40·60, 60·80, and 80·100 kg, with feed conversion efficiency (FCE) as the main response criterion.Response to increased digestible energy (DE) allowance was curvilinear; FCE improved rapidly up to 2·2M-2·6M, and changed much less with intakes above 2·6M. It is concluded that optimum FCE occurs at about 2·7M for pigs of 30 kg and at about 3·OM for pigs of 50, 70 and 90 kg.Allowances of dietary DE suggested by the Agricultural Research Council correspond to 2·56M, 2·95M, 3·04M and 3·08M for pigs of 30, 50, 70 and 90 kg live weight, respectively. It appears that these are near to the optima in promoting the best FCE.Changes of −25%, −15%, −5%, +5% and +15% in daily intake around the optimum levels caused FCE to deteriorate by averages of about 13%, 4·5%, <1%, <1% and 4·5% respectively. Daily weight gains would then change by about −34%, −18%, −5%, +4% and +10%, respectively.


1970 ◽  
Vol 75 (1) ◽  
pp. 11-18 ◽  
Author(s):  
R. P. Andrews ◽  
E. R. Ørskov

SUMMARYThe live-weight gains of male and female lambs were measured during growth from 16 to 40 kg live weight when five cereal-based diets varying in dietary crude protein concentration (from 10 to 20%) were given at three levels in a 5×3×2 factorial design.Males grew faster than females by about 15% (P < 0·001); this difference increased with age and with the amount of feed given (P < 0·05). Growth rate responded linearly to increase in feeding level (P < 0·001) and curvilinearly to increase in dietary protein concentration (P < 0·01). A significant interaction (P < 0·01) occurred whereby growth increased with higher protein concentrations as feeding level increased.At the highest feeding level (near ad libitum) the results suggest that the optimum dietary crude protein concentration for growth was about 17·5, 15·0, 12·5 and 12·5% at body weights of 20, 25, 30 and 35 kg respectively. The overall optimum dietary crude protein concentration for growth between 16 and 40 kg body weight was about 17·0, 15·0 and 11·0% when the mean digestible energy intake was 3·0, 2·6 and 2·1 Mcal/day.The results agree reasonably well with estimates of protein requirements for lambs given by the Agricultural Research Council (1965).


1978 ◽  
Vol 18 (95) ◽  
pp. 781
Author(s):  
EB Greer ◽  
CE Lewis

A 2 x 2 x 3 x 3 factorial experiment with 72 growing pigs examined the effect of adding salt, calcium and phosphorus (Ca + P) and trace minerals (TM-manganese, zinc, iron and copper) to a wheat/soybean meal diet. Gilts and barrows were individually fed at restricted intakes from 20 kg liveweight. Pigs required both salt and Ca + P to reach slaughter at 73 kg. Without these minerals they stopped growing; lameness and broken bones were also common. All pigs fed salt plus the higher level of Ca + P (0.84 and 0.57 per cent, respectively) completed the experiment but only half those fed salt plus the lower level (0.42 and 0.29 per cent Ca + P, respectively) did so. There was a response to salt within three weeks. In the first four weeks, 0.125 per cent added salt improved growth by 26.5 per cent and feed conversion ratio by 21 per cent. The results indicated that growing pigs require less sodium than currently estimated (Agricultural Research Council). A response to both levels of supplementary Ca + P was seen after about seven weeks with salt and nine weeks without salt. In the first eight weeks of the experiment there were no differences in performance between the two levels of added Ca + P when salt was also used. Between 8 and 12 weeks, pigs fed the higher level grew 17 per cent faster. Although 0.84 + 0.57 per cent Ca + P increased rib Ca and P levels, foot and joint abnormalities showed that these levels were insufficient for normal bone development. This suggests that the Agricultural Research Council estimates of Ca and P requirements for restrictively fed growing pigs are low. TM supplementation did not affect performance when both salt and Ca + P were added to the diet.


2009 ◽  
Vol 33 (6) ◽  
pp. 1637-1642 ◽  
Author(s):  
Rodrigo Palomo de Oliveira ◽  
Juan Rámon Olalquiaga Perez ◽  
Joel Augusto Muniz ◽  
Antonio Ricardo Evangelista ◽  
José Camisão de Souza ◽  
...  

The experiment was carried out in the sheep division of Universidade Federal de Lavras, aiming to evaluate the effect of different concentrate : voluminous ratio on the performance of Santa Inês lamb after wean. 40 lambs, male uncastrated, were used and fed with four different diets: diet A (100% concentrate), diet B (75:25 concentrate : voluminous) , diet C (50:50 concentrate : voluminous) , diet D (25:75 concentrate : voluminous). The experimental diets were isoproteic, differing only on its levels of concentrate : voluminous and balanced to meet the nutritional demands according to the recommendation of the Agricultural Research Council (1980). The experimental period was not pre-established, because it corresponded to the necessary period for the last lamb to reach the live weight of 35kg. The dry matter consumption (DMC), crude protein consumption (CPC), fiber in neutral detergent consumption (FNDC) and fiber in acid detergent consumption (FADC), were affected by the different concentrate : voluminous ratio, in which, the animals that received diets with higher concentrate inclusion presenting better results for the variables related to the development. The lambs fed with the diet containing higher inclusion of voluminous did not present weight gain, on the contrary, presented weight loss, since none of the animals reached slaughter weight and the mortality rate was extremely high (80%).


1991 ◽  
Vol 116 (1) ◽  
pp. 111-117 ◽  
Author(s):  
D. C. Patterson

SUMMARYDiets with added fat at 25, 50 and 100 g/kg were formulated with four blends of beef tallow: soya oil, namely 100:0, 75:25, 50:50 and 0:100. An additional diet had no added fat (control diet) to give an experimental design of (3 × 4) + 1. A total of 96 individually penned pigs was used (mean initial and final live weights of 22·4 and 87·5 kg, respectively). The experiment was carried out during the period July 1985 to February 1986 at the Agricultural Research Institute, Hillsborough. Equal numbers of boar and gilt blocks were used and the pigs were fed individually to a scale to give equal amounts of digestible energy: live weight0·75 Neither concentration of fat nor blend of fat had any significant effect on the rates of live weight or carcass weight gain. Increasing concentration of fat significantly improved the carcass feed conversion ratio (P < 0·001), but the blend of fat had no significant effect. Neither killing-out yield nor the intake of digestible energy per unit of carcass gain was significantly affected by the concentration of added dietary fat nor the blend of fat. Fat treatments did not significantly affect the lean plus bone content of the ham joint, drip loss from or the depth of colour of the longissimus dorsi or the weight of flare fat. No evidence was found of synergistic effects between the fat and nonfat components of the diet nor between fats within the blends of fat on growth, digestible energy consumed per unit of carcass gain and carcass attributes. Boars had a more efficient conversion of feed to carcass gain than gilts (P < 0·01).


1987 ◽  
Vol 45 (3) ◽  
pp. 383-394 ◽  
Author(s):  
J. R. Newbold ◽  
P. C. Garnsworthy ◽  
P. J. Buttery ◽  
D. J. A. Cole ◽  
W. Haresign

ABSTRACTGroups of eight Friesian steers were given one of eight diets from 114 to 300 kg live weight. The iso-energetic diets were formulated to supply four levels of protein degradability within two concentrations of crude protein (CP), giving a range of rumen-degradable protein (RDP) and undegradable dietary protein (UDP) concentrations both above and below Agricultural Research Council (1980) recommendations. There were significant (P < 0·05), positive, linear responses of mean daily dry-matter (DM) intake (DMI) (g/kg M°75) to RDP concentration (g/kg DM) for both the low CP diets (DMI = -98·0 + 1·76 (RDP); P = 0·013) and the high CP diets (DMI = -157·5 + 218 (RDP; P = 0017). For the high CP diets, there was a significant (P = 0·045) positive, linear response of live-weight gain (LWG) (kg/day) to UDP concentration (LWG = 0·47 + 0·017 (UDP); P = 0·045). No such response was observed for the low CP diets, where the range of UDP concentrations supplied was smaller than expected. For both the low and high CP diets, LWG decreased as metabolizable energy, UDP and RDP intake increased. These negative responses to nutrient intake were reflected in a wide discrepancy between observed rates of gain and those predicted by current energy and protein nutrition systems. Interactions between food intake and digestive processes, which obstruct effective interpretation of these results, should form an explicit part of any revised protein nutrition scheme.


1972 ◽  
Vol 14 (2) ◽  
pp. 219-228 ◽  
Author(s):  
R. Cooke ◽  
G. A. Lodge ◽  
D. Lewis

SUMMARYOne hundred and twenty eight gilts by Landrace sires out of Large White × Landrace females were allocated on the basis of litter relation-ship and initial weight to 16 treatments involving the individual feeding of four dietary protein levels (approximately 15%, 18%, 21% and 24% CP) at each of four energy levels (2830, 3100, 3375 and 3585 kcal DE/kg air-dry feed). Amino acid balance (as% of total CP) was maintained relatively constant, using synthetic lysine and methionine where necessary. Growth performance was measured over a live-weight range of 23 kg to 59 kg, at which latter weight the pigs were slaughtered for carcass evaluation by dissection of the middle ‘joint’ from a half carcass. Linear carcass measure-ments were also taken. There was a significant energy × protein interaction only for killing-out percentage; for all other measures the main effects could be assessed independently. Increase in dietary energy value gave linear increase in growth rate (GR) and improve-ment in efficiency of feed conversion (EFC), accompanied by linear decrease in lean percentage and increase in fat percentage. Increase in dietary protein level gave an increase in GR and improvement in EFC with the first increment (from 15% to 18% CP), but depressions in both these characteristics with the final increment (from 21% to 24% CP). Lean percentage increased and fat percentage decreased with the first protein increment, with no further significant changes. Calculation of daily rates of tissue deposition indicated that maximum rate and efficiency of fat-free carcass gain could be attained with the second lowest energy and protein levels tested (i.e. 3106 kcal DE/kg and 18·2% CP).


1956 ◽  
Vol 47 (4) ◽  
pp. 435-448 ◽  
Author(s):  
K. J. Carpenter ◽  
J. Duckworth ◽  
I. A. M. Lucas ◽  
D. H. Shrimpton ◽  
D. M. Walker

1. Growth and feed conversion efficiency of pigs between weaning and 100 lb. live weight were improved by adding a vitamin B12 a supplement to simplified all-plant rations containing, principally, barley and groundnut meal. This response was obtained with less than one-third of the U.S. recommended allowance of vitamin B12 in the rations of growing pigs.2. No such response was obtained when a vitamin B12 supplement was added to rations containing milling by-products and grass meal.3. When pigs were fed to a scale based on live weight, those that received an all-plant ration (containing milling by-products and grass meal, and relying on groundnut meal as the main source of supplementary protein to give a total content of 18·4 to 18·8% crude protein) gave 90–93% as good growth as pigs that were fed rations of similar total digestible nutrient content containing 14·5–15·5% crude protein and 3·6 or 7·0% white fish meal. Calculations suggest that such groundnut meal rations may be slightly deficient in lysine, but probably not deficient in tryptophan or ‘cystine + methionine’.4. When pigs were fed to appetite, those that received rations containing 3·6% white fish meal and no milling by-products or grass meal, ate significantly more than those that had either ‘milling by-products + grass meal’ or no fish meal in their rations; they grew proportionately faster, with no improvement in the efficiency of feed conversion.5. The carcasses of pigs that had received all-plant rations from weaning to bacon weight were of good quality, and their measurements did not differ from those of pigs that had received fish meal to 100 lb. live weight.


1978 ◽  
Vol 40 (2) ◽  
pp. 337-345 ◽  
Author(s):  
A. Z. Mehrez ◽  
E. R. Ørskov

1. Early-weaned lambs were used to estimate the concentration of urea required to give the maximum intake and utilization of maize or barley with either a high (HPB) or low (LPB) protein content.2. Approximately the same concentration of urea (7–11 g urea/kg feed) was required for maximum intake and feed utilization of both HPB and LPB. With maize there was no increase in intake, live weight gain, digestion and feed conversion as a result of adding more than 7 g urea/kg.3. The proportion of protein degraded in the rumen was estimated by the synthetic fibre bag technique to be 0.69, 0.82 and 0.54 for HPB, LPB and maize respectively. The similarity in concentration of urea required for the optimum utilization of LPB and HPB might be explained by differences in the extent of degradation of protein in the rumen, but the lower concentration of urea required for maize cannot be similarly explained.4. From estimates of yield of microbial protein in the rumen, the extent of rumen fermentation and the measured extent of protein degradation, theoretical requirements for urea were calculated and compared with other predictions and with the experimentally determined values. For barley, predicted values agreed reasonably well with experimental ones, but for maize all values, including those derived by a new system adopted by the Agricultural Research Council (ARC) Working Party, were too high.


1964 ◽  
Vol 62 (3) ◽  
pp. 369-376 ◽  
Author(s):  
D. W. Robinson ◽  
J. T. Morgan ◽  
D. Lewis

1. A feeding trial involving 128 individually fed Large White pigs was carried out using four levels of dietary energy in combination with four levels of crude protein in the ‘growers’ rations of bacon pigs. Growth rate, food conversion efficiency, carcass quality and nitrogen balance were the parameters measured.


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