The effect of level of dietary protein on the carcass composition of bacon pigs

1965 ◽  
Vol 7 (3) ◽  
pp. 363-376 ◽  
Author(s):  
D. W. Holme ◽  
W. E. Coey ◽  
K. L. Robinson

SUMMARYThe paper reports the results of experiments to study the effects of different levels of dietary protein on the performance and carcass quality of bacon pigs fed on a high-energy diet: (a) to make similar rates of live-weight gain on all treatments, (b) to make similar rates of live-weight gain but with the level of protein on some treatments being reduced at 130 lb., (c) to allow ad libitum feed intake on all treatments, (d) to obtain two distinctpatterns of growth (fast-fast and slow-fast) on each of two levels of dietary protein.In the comparison of the two contrasting patterns of growth there was no significant interaction between rate of gain during the period 40–125 lb. live-weight and level of dietary protein. Differences in carcass density and linear measurements were significant and the results suggest that irrespective of growth pattern there was a carcass response to level of protein.Where diets of different protein content were given ad libitum or to obtain a uniform growth pattern on all treatments, growth rates were generally good, with little difference in feed intake between the treatments within each experiment; variations in level of protein therefore had little effect on growth rate. In some of the comparisons, significant carcass differences were found in terms of density, dissection data and linear measurements; in others only the density differences were significant.The results suggest that with each of the feeding systems a level of about 17% crude protein, associated with 12% fish meal, is more likely than lower levels to give lean bacon carcasses. In the one experiment in which the protein level was reduced at 130 lb. live-weight there was no marked effect on carcass composition.

animal ◽  
2017 ◽  
Vol 11 (6) ◽  
pp. 991-999 ◽  
Author(s):  
G.G. Miguel-Pacheco ◽  
L.D. Curtain ◽  
C. Rutland ◽  
L. Knott ◽  
S.T. Norman ◽  
...  

1974 ◽  
Vol 18 (1) ◽  
pp. 67-73 ◽  
Author(s):  
D. Levy ◽  
Z. Holzer ◽  
H. Neumark ◽  
S. Amir

SUMMARYIn an experiment with group-fed cattle from 6 months of age to slaughter at 480 kg live weight two levels of feed intake: 1, ad libitum, 2, 85% of ad libitum amount, were combined with two ratios of concentrate to hay: a, 70: 30; b, 30: 70. In two further treatments, 3a and 3b, the cattle were fed diets a or b at 70% of ad libitum from 6 to 10 months and ad libitum thereafter.Daily gain during the first 124 days of the experiment was (in grams) 1293, 983, 1097, 846, 992 and 756, and from the 125th day to slaughter 735, 600, 796, 579, 830 and 714, for treatments la, lb, 2a, 2b, 3a and 3b, respectively. The decline in rate of gain from the first period to the second was inversely related to the level of feed intake and to the percentage of concentrates in the ration in the first period.Daily carcass gain was 582, 393, 532, 350, 531 and 368 g for treatments la, lb, 2a, 2b, 3a and 3b, respectively.The treatments that were switched over from 70% of ad libitum feed intake in the first period to 100% in the second (3a and 3b), exhibited considerable compensatory growth in the second period, but this was not sufficient to be of economic advantage.The overall ME requirement per kg of live-weight gain was inversely related to rate of gain. Of the six treatments, 2a (85% of ad libitum, 70% concentrate) was the most efficient (19·8 Mcal/kg live-weight gain).Animals on the 100% level of feed intake throughout the experiment (treatments la, lb) were significantly fatter than those on the other treatments.


1968 ◽  
Vol 71 (3) ◽  
pp. 311-318 ◽  
Author(s):  
N. Walker ◽  
D. W. Holme ◽  
T. J. Forbes

SUMMARYTwo experiments were carried out in which pigs were grown at controlled high, moderate or low growth rates from 18 kg to slaughter at 57 kg live weight. Linear measurements and density determinations were carried out on the carcasses. In the second experiment the right-hand side of each carcass was divided into four joints and each joint was physically dissected into three components, bone, subcutaneous fat plus skin and ‘lean’ meat. The boneless tissue of each joint was analysed for moisture, ether extractable fat and nitrogen.It was found that an increase in the rate of live-weight gain tended to improve the efficiency with which feed was converted into live weight.The percentage of fat in the side was significantly increased by more rapid growth rates.The conformation of the side was altered by treatment, the proportion by weight of the middle region increased with increasing rate of live-weight gain and was accompanied by corresponding reductions in the proportions of the gammon and shoulder regions. These changes were largely due to an effect on the distribution of fat throughout the side, but there were also minor changes in the distributions of bone and fat-free lean.The high rate of gain was associated with a greater proportion of belly in the side. This was due to an increase in the proportion of lean meat in this region, presumably a functional effect caused by an increased intestinal volume.There was no treatment effect on the chemical composition of the fat-free boneless meat which was found to differ significantly between joints.


1967 ◽  
Vol 9 (4) ◽  
pp. 535-545 ◽  
Author(s):  
J. H. D. Prescott ◽  
G. E. Lamming

1. A factorial split-plot experiment was conducted to investigate the growth of entire and castrate male pigs on conventional diets and diets containing higher levels of protein. Thirty-two Large White pigs were fed ad libitum from 50 lb to slaughter at 260 lb live weight. The carcasses were dissected.2. The live-weight gain of entire males was the same as that of castrates on the conventional diet, but they grew non-significantly faster than castrates on the higher protein diet.3. The entire males had a lower dressing percentage and less fat in the carcass than the castrates, but more lean, bone and rind, and a similar lean: bone ratio. The leanness of the entire males was increased on the higher level of dietary protein whereas the leanness of the castrates was unaffected except in the leg. The interactions were not significant.4. The carcasses of the entire males were proportionately heavier in the head and shoulders and lighter in the middle than those of the castrates.5. The majority of the entire males had flesh with a slightly tainted flavour.


1980 ◽  
Vol 95 (2) ◽  
pp. 349-355 ◽  
Author(s):  
D. M. Murray ◽  
Olga Slezacek

SUMMARYThe effect of three different growth patterns from 15 to 40 kg live weight on the feed utilization of lambs was studied. The treatments were: high (H) ad-libitum feed intake, low (L) restricted feed intake and high-maintenance-high (HMH) ad-libitum feed intake from 15 to 25 kg followed by a 50-day period during which live weight was maintained constant, which in turn was followed by ad-libitum feeding. Animals were individually penned and fed a pelleted lucerne chaff-cereal grain mixture. Intakes of pellets were converted to digestible organic matter (DOM) using the results of in-vitro digestion studies. Two animals were killed at the start of the experiment (15 kg) and the remaining 27 animals (nine in each treatment) were killed at common live weights of 25, 30, 35 and 40 kg.A marked reduction was observed during weight stasis at 25 kg in the amount of DOM required daily by the HMH animals to maintain live weight. Despite marked compensatory growth by the HMH animals which were rehabilitated after the period of weight stasis, DOM intakes were similar in both these HMH animals and a corresponding number of H animals over identical live-weight ranges.Differences between treatments were found in DOM intake per unit live-weight gain (H < HMH < L), empty body-weight gain (H = HMH < L) and carcass weight gain (H < HMH = L) from 15 kg until slaughter. DOM intake was utilized more efficiently for gains of all these components by HMH animals during compensatory growth compared with H animals over the same live-weight ranges.DOM intakes were related to energy gains in the carcass both for all animals in each treatment from 15 kg until slaughter, and for the H and HMH animals which were killed at 30, 35 and 40 kg from 25 kg. Comparisons of these data showed treatment differences in the efficiency of DOM conversion to carcass energy (H > HMH > L) and that DOM was utilized no more efficiently by HMH animals during compensatory growth than by H animals over identical live-weight ranges.It is concluded that the increased efficiency of utilization of DOM for carcass gain during compensatory growth was due to changes in carcass composition during the period of weight stasis.


2011 ◽  
Vol 51 (No. 2) ◽  
pp. 47-53 ◽  
Author(s):  
L. Bartoň ◽  
D. Řehák ◽  
V. Teslík ◽  
D. Bureš ◽  
R. Zahrádková

Breed effects on live weight gain, slaughter characteristics and carcass composition were compared in Aberdeen Angus, Charolais, Hereford and Simmental bulls. The experiment extended over 2 years and involved totally 96 animals. The target slaughter live weights were determined 550 kg for earlier maturing breeds Aberdeen Angus and Hereford and 630 kg for later maturing breeds Charolais and Simmental. Charolais and Simmental gained more rapidly (P &lt; 0.05) than Aberdeen Angus while Hereford were intermediate. Hereford had lower (P &lt; 0.05) dressing percentage than the other breeds. Percentages of grade I meat were significantly higher (P &lt; 0.05) in Charolais and Simmental. The highest percentage of separable fat was recorded in Hereford (P &lt; 0.05). Charolais and Simmental had lower (P &lt; 0.05) thickness of subcutaneous fat over MLLT than Aberdeen Angus andHereford. The later maturing bulls generally tended to achieve higher live weight gains during the experiment, produced less fat and had higher percentage of meat from high priced joints in comparison with earlier maturing animals. &nbsp;


1969 ◽  
Vol 11 (1) ◽  
pp. 19-28 ◽  
Author(s):  
D. G. Miles ◽  
R. J. K. Walters ◽  
E. M. Evans

SUMMARYA series of animal feeding trials was designed to determine differences between grasses in dry-matter intake and animal live-weight gain, with a view to indicating better selection criteria for improving the feeding value of herbage.Wide differences were demonstrated in feed intake and live-weight gain between single-variety grass feeds at similar levels of digestibility.S.37 cocksfoot gave consistently good and S.51 timothy, consistently poor responses.Supplementation of grass feeds with red clover frequently resulted in marked improvement in feed intake and animal performance.


1983 ◽  
Vol 36 (3) ◽  
pp. 445-451 ◽  
Author(s):  
M. J. Bryant ◽  
P. Rowlinson ◽  
H. A. M. Van der Steen

ABSTRACTNursing frequency, suckling duration and teat order were recorded in 12 ‘hybrid’ sows and their litters from parturition to weaning at day 42 post partum. Sows and their litters were moved from the farrowing quarters at day 20; half were housed as a group (G) and fed ad libitum with a boar present and the other half were housed individually (S) with no boar present and ration-fed to scale.Some differences occurred in behaviour from day 20. A significantly greater number of false nursing periods, significant synchronization of nursing periods, and a tendency for more long and short nursing intervals occurred in G than S sows and litters. The duration of the preliminary nosing phase and the total nursing period were significantly longer in S than G litters. Teat order scores, indicating consistency of piglet suckling position on the sow, tended to be greater in S than G litters, and there was a fall in the score for G litters in the weeks following grouping. This was associated with a check in live-weight gain.All G sows showed oestrus during lactation, on average 15 days after grouping. There was no incidence of lactational oestrus in the S sows which showed oestrus 5 days after weaning.


1970 ◽  
Vol 12 (1) ◽  
pp. 63-70 ◽  
Author(s):  
H. Swan ◽  
G. E. Lamming

SUMMARY1. Three groups, each of eight steers, were fed on pelleted diets containing 30, 50 or 70% ground barley straw, maize and soya bean meal. On an air-dry basis the diets contained 12% crude protein.2. Daily live-weight gain was 1·29, 1·19 and 1·02 kg/day for the 30, 50 and 70% straw diets respectively, and was negatively related to the percentage of crude fibre in the dry matter (r = −0·61, P < 0·05).3. The apparent digestibility of dry matter, determined in sheep at the maintenance level of feeding was negatively related to percentage crude fibre in the dry matter (r = −0·91, P < 0·001).4. All animals were killed at approximately the same live weight, which was reached on average in 140,153 and 163 days by the 30, 50 and 70% groups, respectively.5. The differences in mean carcass weight between treatments were significant (P < 0·05). Killing-out percentage was significantly reduced (P < 0·05) as the proportion of ground barley straw in the diet was increased from 30 to 70%.6. The proportion of straw in the diet had no direct effect on the composition of carcass gain.7. The results are discussed in relation to the intake of digestible energy.


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