Greater Carcass Weight Research Articles

Effects of dietary chromium (III) picolinate on growth performance, respiration rate, plasma variables, and carcass traits of pigs fed high‐fat diets

Effects of dietary chromium (III) picolinate (CrPic) on leanness and fat deposition of pigs have been inconsistent. We investigated the effects of supplemental CrPic on pigs fed high‐fat diets (HFD). Crossbred pigs (n = 32; 9.6 ± 1.6 kg BW) were allotted to 4 treatments with 4 blocks and 2 pigs/pen. Treatments included: 1) low‐fat diet (fat < 3.5%; LFD) with no CrPic, 2) HFD (fat > 30%) with no CrPic, 3) HFD with 1,000 ppb Cr as CrPic, and 4) HFD with 2,000 ppb Cr as CrPic. During d 0 to 56, pigs fed HFD gained faster, consumed less feed, and had lower feed:gain (P < 0.05). CrPic resulted in a quadratic increase (P < 0.05) in feed:gain of pigs fed the HFD. Pigs fed HFD had higher respiration rates than pigs fed LFD on d 41 (P < 0.01) and d 55 (P = 0.06) with no effect of CrPic. Plasma insulin on d 14 linearly decreased with CrPic (P = 0.05). Consumption of HFD resulted in greater carcass weight, perirenal fat, and backfat measures (P < 0.01) and in lower carcass fat‐free lean percentage (P < 0.01) compared with the LFD group. CrPic resulted in linear reductions of carcass weight (P = 0.08) and average carcass backfat (P < 0.05). The effects of CrPic on carcass fat measures were more pronounced in barrows than in gilts. These results indicate that CrPic attenuates some effects of HFD, mainly body fat accretion of pigs, and especially in barrows.

Effects of Body Condition, Initial Weight, and Implant on Feedlot and Carcass Characteristics of Cull Cows

Feeding cull cows an energy-dense diet can increase amount and quality of marketable product. Furthermore, implanting cull cows with steroid implants may improve BW gain, feed efficiency, carcass traits, and overall eating quality. Therefore, objectives of this study were to determine effects of implant, initial BW, and body condition score (BCS) at the beginning of the study, on feedlot performance and final live animal and carcass weights, and carcass characteristics of cull cows fed a high-concentrate diet for approximately 90 d. One-half (68) of the cows were allotted to implant treatment (Synovex-Plus®) by initial BW and BCS. Cows were fed a warm-up diet (50 to 60% concentrate, DM basis) for 14 d and then fed a finishing (80 to 85% concentrate, DM basis) diet for the remainder of the study. Variations in initial BW of cows were associated positively (P<0.10) with final BW, hot carcass weight, longissimus area, and yield grade. Initial BCS had a positive affect (P<0.10) on fat thickness but did not influence (P>0.10) ADG, final BW, or other carcass traits. Implant influenced (P<0.05) both feedlot and carcass characteristics; implanted cattle had 18 kg greater final BW, 0.22 kg greater ADG, 18 kg greater carcass weight, 8.6 cm2 larger longissimus area, 27 units (100 units per marbling score) less marbling and 0.24 units less yield grade. Initial BW, BCS, and implanting influence feedlot performance and carcass characteristics of cull cows.

Growth and carcass production of young farmed deer grazing sulla (Hedysarum coronarium), chicory (Cichorium intybus), or perennial ryegrass (Lolium perenne)/white clover (Trifolium repens) pasture in New Zealand

Liveweight gain, voluntary feed intake, and carcass production were compared for pure red and hybrid (0.75 red: 0.25 elk) deer calves grazing sulla (Hedysarum coronarium cv. Necton), chicory (Cichorium intybus cv. Grasslands Puna), or perennial ryegrass (Lolium perenne cv. Nui)/white clover (Trifolium repens cv. Huia) pasture from weaning in March to slaughter in December of the same year, at approx one year of age. Organic matter digestibility (OMD) of diet selected was similar for all forages during autumn, but OMD of chicory (88.4%) was greater than both sulla (78.3%) and pasture (83.8%) during spring (P < 0.05). Sulla diet selected contained 5.1% condensed tannin (CT) in autumn and 8.4% CT in spring (P < 0.05); pasture and chicory contained 0.14–0.26% CT. VFI of deer grazing sulla was greater than for deer grazing chicory in autumn (2027 versus 1014 g OM d−1; P = 0.07), but not spring (2029 versus 2251 g OM d−1). In autumn, deer gained 293 g d−1 on sulla, 218 g d−1 on pasture (P < 0.01), and 183 g d−1 on chicory (P < 0.001). In winter, deer gained 150 g d−1 on sulla and 133 g d−1 on pasture. Final liveweight of deer grazing sulla was 106 kg, which was significantly higher than 97 kg for deer on pasture or 95 kg for deer on chicory (P < 0.01). Deer grazing sulla had greater carcass weights (59.9 kg) than deer grazing pasture (52.3 kg) or chicory (52.1 kg) (P < 0.01 hinds; P< 0.05 stags). Hybrid stags had significantly greater carcass weights than red stags (64.1 kg versus 56.3 kg; P < 0.01) and hybrid hinds (52.8 kg; P < 0.001). It was concluded that the increased growth and carcass weight of young deer grazing sulla was caused by a higher feeding value of sulla, with a component of this being increased utilisation of digested nutrients.

Effects of grazing sequence and condensed tannins on ingestive behaviour, herbage intake, and performance of lambs grazing Yorkshire fog pasture

A grazing experiment was conducted using Yorkshire fog (Holcus lanatus cv. Massey Basyn)/white clover (Trifolium repens cv. Grasslands Tahora) pasture to assess the grazing behaviour, diet selection, herbage intake, and performance of lambs as affected by low concentrations of condensed tannin (CT) in the grass, and grazing sequence, under rotational stocking management in summer 1994/1995, in New Zealand. Sixty spring‐born castrated male lambs were used in the experiment. Twelve lambs were slaughtered at the start of the experiment to measure carcass weight. Another 48 lambs were allocated to two groups in sets of twenty‐four to graze eight paddocks rotationally in a Leader/Follower sequence. Half of the lambs within each group were drenched with 10 g polyethylene glycol (PEG: mol. weight 3350) twice daily at 0830 and 1630 hours and the remaining lambs were drenched with water as a control. There were higher proportions of grass leaf and white clover and lower proportions of grass stem and dead material in the Leader sward than in the Follower sward, and correspondingly higher proportions of green grass and white clover and a smaller proportion of dead material in the diet samples selected from Leader swards. Leader lambs had greater intake per bite (79 versus 64 ± 3.9 mg OM per bite, P < 0.001), higher total N concentration (2.67 versus 2.35 ± 0.065%, P < 0.01) and in vitro OMD (78 versus 72 ± 0.7 %, P < 0.001) in the diet, and spent more time grazing (660 versus 620 ± 7 min, P < 0.001) than Followers, and their herbage DOM intake was significantly greater (56 versus 43 ± 0.8 g kg−1 W0.75 d−1, P < 0.001). Leader lambs had greater liveweight gain (107 versus 37 ± 5.0 g d−1, P < 0.001), greater carcass weight (15.0 versus 12.5 ± 0.2 kg, P < 0.001), and more wool growth (109 versus 80 ± 2.9 mg 100cm−2 d−1, P < 0.001) than Followers. There was no significant difference in CT concentrations between the diets selected from the Leader and Follower swards (2.59 versus 2.26 + 0.165 g kg−1 DM). Consistent increase in rumen ammonia concentration by PEG administration indicated that the low concentrations of CT in Yorkshire fog reduced the rate of protein degradation in the rumen. However, there were no significant effects of CT on herbage intake, body growth, and wool growth rate of lambs.

Comparative studies of herbage intake and performance of lambs grazing Yorkshire fog (Holcus lanatus) and tall fescue (Festuca arundinacea) pastures under rotational management in summer

Grazing experiments were conducted on Yorkshire fog (Holcus lanatus cv. Massey Basyri)/white clover (Trifolium repens cv. Grasslands Tahora) and tall fescue (Festuca arundinacea cv. Grasslands Roa)/white clover pastures in late spring‐summer (Nov‐Jan, Experiment 1) and summer‐early autumn (Jan‐Mar, Experiment 2) to assess behaviour and performance of lambs and to evaluate the effects of low concentrations of condensed tannins (CT) in the grasses on lamb performance. In each experiment, 48 lambs were allocated to three groups, balanced for previous grazing experience and sex, in sets of 16. One group was slaughtered at the start of the experiment to measure carcass weight; the other two groups of lambs rotationally grazed paddocks within each pasture. Half of the lambs within each pasture were drenched with 10 g polyethylene glycol (PEG; mol. weight 3350) twice daily at 0830 and 1630 hrs and the remaining lambs were drenched with water as a control. There were similar sward surface height, herbage mass, and bulk density on both swards. Yorkshire fog had a higher proportion of sown grass and lower proportions of other grasses and white clover than tall fescue. There was slightly higher total N (3.37 vs 3.30 ± 0.013%, P< 0.05) on tall fescue than on Yorkshire fog in summer, but no significant difference in organic matter digestibility (OMD) for the diets from the two pastures. The diet from Yorkshire fog had higher CT concentrations overall. Herbage organic matter (OM) intake was not significantly different between the two pastures overall, but was significantly reduced by PEG administration in Experiment 2 (P < 0.01 ). Previous grazing experience had no significant effects on lamb performance. Lambs had greater carcass weight (14.7 vs 13.9 ± 0.2 kg, P < 0.05) and faster carcass weight gain (32 vs 20 ± 3.1 g/day, P < 0.05) on Yorkshire fog than on tall fescue in Experiment 1, but not in Experiment 2, and faster rate of clean wool growth on Yorkshire fog than tall fescue in Experiment 2 (123 vs 112 ± 2.8 mg/ 100 cm2 per day, P < 0.05). It is concluded that Yorkshire fog cv. Massey Basyn offers potentially greater nutrient intake and weaned lamb performance than tall fescue cv. Grasslands Roa in summer pastures. The limited content of condensed tannins in the Yorkshire fog pasture had no measurable effects on lamb performance, and it is suggested that particularly low concentrations of CT measured in tall fescue may have been an artefact of the analytical process.

Lack of Interactions Between Dietary Lysine or Strain Cross and Photoschedule for Male Broiler Performance and Carcass Yield ,

The purpose of this study was to test interactions of dietary lysine or strain crosses provided increased lysine with photoschedule on broiler performance and carcass quality. In Experiment 1, treatments were factorially arranged as two lysine levels [control grower and finisher (NRC, 1984) or control grower and finisher plus .15% L-lysine HCl] and two photoschedules [23 h light (L):1 h dark (D) or 14L:10D]. All birds received a control starter feed and dietary treatments were initiated at 22 d of age. In Experiment 2, treatments were factorially arranged as two strain crosses [Peterson × Arbor Acres (PAA) or Ross × Ross (RR)] and two photoschedules (23L or 16L). All birds received standard starter and standard grower and finisher plus .15% L-lysine HCl. There were no lysine by photoschedule or strain cross by photoschedule interactions in this study. The high-lysine diet increased BW, improved feed efficiency, increased lean carcass weight and yield of breast meat, and decreased abdominal fat and yield of thighs. The PAA strain cross had better feed conversion, fewer Grade A carcasses, more back bruises and breast blisters, greater yield of wings and drumsticks, and less yield of breast meat than RR. The 23L had greater BW, better feed efficiency, fewer breast blisters, greater carcass weight (Experiment 1), more abdominal fat (Experiment 2), lower yield of wings (Experiment 1), drumsticks, and thighs, and greater yield of breast meat than the treatments with shorter photoschedules. Increased dietary lysine did not compensate for decreased breast meat yield associated with 14L (Experiment 1).

Chronological age and dentition effects on carcass and meat quality of cattle in northern Australia

The effects of chronological age and dentition on the liveweight, carcass weight, bruising and muscle properties of 348 cows and 370 steers were examined in 5 experiments in Queensland (1982-83). Birth dates were known only for the cows in experiments 1 and 2, and for the steers in experiment 5; with ages categorised as 4 years and less (young), 5-10 years (mature) and greater than 10 years (old). The number of permanent 'incisor' teeth were recorded for all animals. The cattle were weighed (unfasted), transported to an abattoir and given access to water and hay (except in experiment 5). Mustering to slaughter periods varied from 2 to 7 days. Half the carcasses were electrically stimulated in experiments 1 and 2. In general, old and mature cows with 8 teeth had heavier (P&lt;0.05) mean liveweights than did young cows with 4 teeth, and both had heavier (P&lt;0.05) liveweights and carcass weights than those with 2 teeth. Old cows with 8 teeth also had the lowest (P&lt;0.05) mean dressing percentage, while mature cows had the greatest (P&lt;0.05) fat depth. There was no consistent trend between groups in bruise score. Steers with 8 teeth had a greater (P&lt;0.05) mean liveweight, carcass weight, dressing percentage and rib fat depth than other dentition groups, and a greater (P&lt;0.05) bruise score in experiment 5 only. There was no significant effect of chronological age or dentition on the shear force values or cooking losses of M. longissimus dorsi (LD) for cows. In 1 experiment, steers with 8 teeth had a greater (P&lt;0.05) peak force-initial yield value and lower (P&lt;0.05) cooking loss than other dentition groups. Mature cow carcasses cooled more (P&lt;0.05) slowly than those of other ages. Over all experiments, there were more (P&lt;0.05) high pHz4 carcasses among the combined 6 and 8 teeth group than the combined 2 and 4 teeth group (10.2 v. 2.3%).

Growth, tissue deposition and metabolism studies in growing pigs given low glucosinolate rapeseed meal diets containing different amounts of copper and polyethylene glycol

SummaryIn three factorial growth experiments and a metabolism experiment pigs of approximately 25 kg initial live weight were given on a restricted scale of feeding simple diets, based on barley, a vitamin and mineral supplement and either soya-bean meal (SBM) or a low glucosinolate rapeseed meal (cv. Tower; TRSM). Variations in these two basic diets were produced by adding different quantities of tannic acid, polyethylene glycol (PEG) and copper (Cu).Diets based on soya-bean meal were used in the first experiment. There were no significant interactions. Tannic acid added at 3·75 and 7·50 g/kg air-dry matter was without significant effect on performance compared with no tannic acid addition, but PEG at 17 g/kg air-dry matter significantly improved growth rate compared with no PEG addition to the diet (P &lt; 0·05). In the second experiment TRSM-based diets were used. There were no significant interactions and no significant effects on performance from adding 0, 8·5 and 17·0 g PEG/kg air-dry matter. Increasing Cu from 17 to 54 mg/kg air-dry diet significantly improved growth rate (P &lt; 0·05). In the third experiment TRSM and SBM based diets, of similar digestible energy (DE), crude protein and lysine content, and containing either 19 or 202 mg Cu/kg air-dry matter, were used. Pigs were slaughtered at 87·5 kg live weight and hand joints dissected. Pigs given the TRSM diet containing 19 mg Cu/kg grew significantly more slowly than pigs given the three other diets between which there were no significant differences. There were no other significant interactions and no significant differences between Cu concentrations for the growth, carcass and efficiency of conversion results. Compared with TRSM diets, SBM diets at similar slaughter weights gave significantly greater carcass weights, killingout proportions and backfat thicknesses. Also the efficiencies with which dietary protein and DE were used to promote units of carcass growth were significantly better for the SBM diets, but there were no significant differences in the estimated weights of lean in carcasses.In the metabolism experiments the effects of adding PEG to diets similar to those used in the growth experiments were examined. The apparent digestibilities of dry matter, gross energy and nitrogen and the nitrogen retentions were significantly greater for the SBM diets than for the TRSM diets. The addition of PEG to the SBM and TRSM diets significantly decreased the apparent digestibilities of dry matter and gross energy, and significantly increased the apparent digestibility of nitrogen in the SBM diet but not in the TRSM diet.

Comparison of some properties of beef from animals homozygous or heterozygous for muscular hypertrophy

Carcass characteristics and meat properties of fifty-eight steers and heifers heterozygous (M +) for muscular hypertrophy were compared with those of fifteen homozygous (M M) steers and heifers. The M M animals had a greater carcass weight (173 versus 162 kg) and killing-out percentage than M+ animals. Age at slaughter (298 days for M M and 304 for M +) and liveweights (280 kg, M M, versus 287 kg) did not differ significantly. Carcasses from M M animals were significantly shorter, with a greater eye-muscle area and thinner subcutaneous fat cover over the loin, than those from M + animals. M. semitendinosus (ST) muscles had similar sarcomere lengths, ultimate pH values and weight losses during cooking—80°C for 90 min—for M M and M + animals. Adhesion values, both peak force and work done, were less for ST samples from M M than M + animals, indicating that the ST of M M animals was potentially more tender. This, and other work, suggests that the mechanical properties of cooked ST samples of M+ animals are intermediate between those of M M and + + animals with the ST of M M animals being the most tender. No dark-cutting, high ultimate pH (>6·0) samples were found in the fifteen M M animals slaughtered commercially in the present experiment.

The effects of added dietary lipid on the body composition of rams and wethers

SUMMARYA 2 × 3 factorial trial designed to investigate the effects of castration and three diets on growth and body composition of 30 male Dorset Horn × (Border Leicester × Merino) lambs is described. The three diets were: (a) a standard ration of equal weights of lucerne chaff and pelleted concentrates; (b) a similar ration to (a) plus 7·5% by weight of lipid (peanut oil and tallow); (c) a greater ration of (a) calculated to be isocaloric for digestible energy with diet (b).At the beginning of the trial a group of 40 lambs (20 rams, 20 wethers) were shorn and five rams and five wethers were selected at random and slaughtered to establish initial body composition. The remaining 30 lambs, 15 rams and 15 wethers aged about 22 weeks and having mean weights of 33·0 kg (rams) and 31·2 kg (wethers), were randomly divided within sex into three groups and allocated to the three diets for 92 days. At the end of this period the lambs were again shorn, and then slaughtered and dressed.During the trial, rams gained significantly (P &lt; 0·001) more weight than wethers, and lambs on diet (a) gained significantly (P &lt; 0·01) less weight than those on (b) and (c). Weight gains on the latter two diets were similar. Diet generally had little effect on body composition, although there was a tendency, within sexes, for lambs on diet (b) to have a greater fat content than those on the other diets. Rams had significantly greater carcass weights (P &lt; 0·01), head percentage (P &lt; 0·001) and various m. longissimus dorsi dimensions than wethers, but significantly less fat in all the locations measured, including a lower percentage of chemically extractible fat in the offals and carcasses. Estimations of the energy stored in the wool-free body during the trial indicated that wethers stored significantly more energy in the form of fat than rams (P &lt; 0·001), but that rams stored significantly more non-fat energy than wethers (P &lt; 0·001). It is concluded that a maximum growth rate exists for the non-fat body, and that it is higher in rams than wethers. Thus the addition of dietary lipid (which increases energy intake with comparatively small increases in weight or volume of feed), is more likely to promote fat deposition in wethers, which have a lower maximum capacity for non-fat storage, than in rams.

TISSUE DEVELOPMENT IN SWINE AS INFLUENCED BY LIVEWEIGHT, BREED, SEX AND RATION

Carcasses of 73 pigs taken from an experiment which involved 144 barrows and gilts of Duroc × Yorkshire, Hampshire × Yorkshire and Yorkshire × Yorkshire breeding, fed either a high energy (HE) (3652 kcal DE/kg) or a low energy (LE) (2757 kcal DE/kg) ration, and slaughtered at 68, 91 and 114 kg liveweight, were dissected to study tissue development and carcass composition in pigs. To establish a starting point, an additional nine barrows and eight gilts of the same breed groups were slaughtered at 23 kg liveweight. A normal pattern of tissue growth was shown to occur, bone growth being relatively slow and muscle growth relatively fast. Fat deposition paralleled muscle growth from 68 to 91 kg liveweight, after which fat deposition exceeded muscle growth in absolute amount. Breed of sire tended to influence the carcass, muscle and fat weight per day of age as well as the proportions of lean and fat in the carcass. Gilts had more muscle per day of age and a greater percentage of muscle and less of fat than barrows. Barrows had a greater carcass weight and more fat per day of age than gilts. The LE ration resulted in higher percentage of muscle and lower percentage of fat in the carcass than did the HE ration. At all slaughter weights, the differences in the proportions of muscle, fat and bone between barrows and gilts were similar to the differences resulting from the HE and LE rations. Carcasses from gilts slaughtered at 114 kg liveweight were equal in composition to those from barrows slaughtered at 91 kilograms. Similarly, pigs fed the LE ration at 114 kg had equal carcass composition to HE-fed pigs at 91 kilograms. The data indicated that there may be some justification for extending the weight range in the Canadian grading system such that carcasses of superior composition outside the present weight range would be recognized on their merit. Some interactions occurred among breed, sex and ration groups reflecting differences in energy intake and partitioning of nutrients for tissue growth.