Reach Slaughter Weight Research Articles

Carcass quality of crossbred lambs expressing the callipyge phenotype born to Romanov purebred and crossbred ewes

AbstractCarcass quality was evaluated in 35 male and 41 female lambs, 38 expressing the callipyge phenotype (Cg) and 38 controls expressing the normal phenotype (N). Lambs were from Romanov and Suffolk × Romanov ewes mated to two rams heterozygous for the callipyge locus and slaughtered at approximately 44 kg live weight. The Cg lambs reached slaughter weight at 163 days of age, 13 days younger, and had a dressing proportion 0·524 , 0·029 points higher. Also they had more leg (341 v. 308 g/kg), less loin (315 v. 328 g/kg) and less shoulder (340 v. 360 g/kg) than the N lambs. The leg, loin and shoulder wholesale cuts and half the carcass of Cg lambs had 81, 113, 77, and 92 g/kg more lean and 52, 98, 59, and 72 g/kg less fat than N lambs, respectively. The Cg lambs also had larger loin-eye area (18·5 v.13·1 cm2), less backfat at the C (4·1 v. 6·1 mm) and at the GR locations (11·0 v. 15·2 mm) and less internal fat (202 v. 339 g) than the N lambs. Dissection of the 12th rib indicated that Cg lambs had more muscle (574 v. 462 g/kg), less fat (276 v. 358 g/kg) (both P < 0·001) and similar (V > 0·05) bone (155 v. 265 g/kg) to N lambs. Colour of the longissimus muscle was significantly paler in Cg lambs. Intramuscular fat and dry matter of longissimus muscle were significantly lower (49 v. 120 and 247 v. 253 g/kg) in Cg than in N lambs. Cg lambs were significantly different (P < 0·05) from N lambs for all traits studied except age at slaughter, tissues at the GR location, proportion of bone in the 12th rib and the L* colour of the longissimus muscle. Breed type effect was significant only for age at slaughter, whereas the effect of sex was significant for all traits except for proportion of lean in the leg, b* colour and intramuscular fat content of the longissimus muscle. No interactions were significant except phenotype × breed type on fat thickness over the longissimus muscle. Post-mortem ageing of the longissimus muscle for 9 or 15 days caused a significant reduction in muscle toughness in Cg lambs compared with those aged for 3 days (113 v. 98 Newtons) but the muscle was still tougher than that from N lambs (with a shear force of 64 and 51 Newtons at 3 and 9 or 15 days post mortem). The principle component analysis including carcass conformation and composition traits as well as meat quality traits was indicative of a distinctly different carcass ofCg compared with N lambs. The first two principal components explained 0·70 of the total variation.

Evaluation of distillery by-products, barley and molassed sugar beet feed for intensive lamb finishing

Intensively reared early weaned lambs are conventionally fed a high energy concentrate diet in order to maximise daily gain and feed conversion efficiency. This reduces both the time required to reach slaughter weight and the overhead costs. However, it is estimated that feed costs in intensive lamb systems amount to 0.24 of the total output value (MLC 1998) and that the profitability is sensitive to relatively small changes in the lamb price to feed cost ratio. The objective of the work was to investigate the effects of various alternative feeds consisting of molassed sugar beet feed (MSBF), distillers products and the whole barley or grainbeet (200 g/kg MSBF and 700 g/kg brewers grain) on the performance and profitability of intensively reared lambs.

Rare and minority British sheep for meat production: the Shropshire and Ryeland as sires, and the Cotswold and primitive breeds as dams

Two groups of comparisons were made between rare and minority British breeds of sheep, and numerically stronger genotypes. In the sire breed trial, Shropshire ( n=5) and Ryeland ( n=4) rams were compared as sires of meat lambs with Suffolk, Oxford Down, Texel and Dorset Down rams at two farms (total lambs marketed: n=732). At the first farm, lambs sired by the Ryeland and the Shropshire made poorer prices than those sired by the Suffolk and Oxford Down, because of small size and low price per kg respectively. At the second farm, the Ryeland and Dorset Down performed similarly in respect of days to slaughter, carcase weight and sale price. The Shropshire conferred rather poorer conformation on lambs than the Suffolk. In the maternal breeds trial, commercial crossbred (control) ewes ( n=84) and ewes of rare breeds (Cotswold n=10; and the primitive breeds Manx Loghtan n=17; Hebridean n=26; Shetland n=16) were mated with terminal sires on four farms. Lambs from Cotswolds reached slaughter condition earlier than control lambs, but were not as remunerative. Lambs from Hebrideans made a better price, per kg and per kg of ewe body weight, than control lambs from commercial crossbreds, but took longer to reach slaughter weight. Generally the primitive breeds produced lighter lambs but their production of lambs per unit of ewe body weight was no different from that of the commercial crossbreds. In this preliminary trial, economic advantages of using rare breeds were not demonstrated, but neither were there obvious economic penalties.

Photoperiodic requirements for rapid growth in young male red deer

AbstractWinter growth of young male red deer can be increased by exposure to 16 h of light (L) and 8 h of dark (D) per day (16L: 8D). This study tested the duration of photoperiod required for this growth response, determined if the time to reach slaughter weight can be reduced and monitored plasma IGF-1, prolactin and reproductive development. Fifty male calves were allocated to five equal groups. Four groups were housed indoors and for 33 weeks from the winter solstice (22 June, southern hemisphere) until 11 February were placed under either 16L: 8D (16L), 13·25L: 10·75D (13L), 10·751:13·25D (111) or 8L: 16D (8L) photoperiods. The fifth group of deer (OC) remained outside in a gravelled enclosure. All groups were given a pelleted diet ad libitum. Group food intake was recorded daily, individual live weight was measured weekly and testes diameter and blood samples taken at weekly or 2-week intervals.Plasma prolactin concentrations in 16L increased within 4 weeks of treatment and were different (P < 0·001) between groups from 14 August to 4 September. IGF-1 increased in both 16L and 13L 4 weeks after treatments and then increased further in 16L above that of 13L (P < 0·01). All groups grew at the same rate for the first 7 weeks. 16L then gained more weight (P < 0·001) than the other groups over the next 19 weeks (50·7 kg v. 38·5 for 13L, 35·7 for 11L, 37·0 for 8L and 37·4 for OC; s.e.d. 3·76). Food intake was positively related to growth rate in a similar way among the inside groups (P < 0·001), however there was a higher energy requirement outdoors (P < 0·05). A target live weight for slaughter of 95 kg was reached 7 weeks earlier for 16L than the other groups (P < 0·01). Testes diameter of 16L was larger than in the other groups from 13 November until 24 December (P < 0·001). The growth oflSL slowed from 1 January while that of OC increased and the live weight ofOC was equal to 16L by the end of the experiment. OC also had the largest testes diameter from 5 February onwards (P < 0·01). The live-weight increase in OC was associated with increases in both prolactin and IGF-1 levels.This study confirmed that 16L: 8D stimulates rapid growth of young male red deer during winter for sufficient time to achieve an earlier slaughter date. The live-weight advantage was lost by late summer however. The increased growth rate was mediated by food intake and associated with increases in IGF-1 and prolactin and earlier reproductive development. Photoperiods of 13 h of light per day or less did not stimulate growth and increases in IGF-1 and prolactin were of a lower amplitude than under 16L: 8D.

Comparative feedlot performance and carcass characteristics of Sudanese desert sheep and goats

Under similar levels of feeding, desert sheep grew faster and reached slaughter weight of 35 kg in a significantly ( P<.001) shorter feeding period than desert goats. Sheep consumed more feed and their gut fill was greater ( P<0.0001) than that of goats. Desert goats had heavier ( P<0.001) carcass weight, higher killing-out proportion but more chilled shrinkage than desert sheep. Weights of wholesale cuts were similar in the two species. Carcass dissection revealed greater muscle proportion in desert goats than in sheep. Bone and fat proportions were significantly heavier in desert sheep, but the muscle : bone ratio was greater in desert goats. Except for its slow growth rate, desert goats can yield heavier carcasses which are leaner than desert sheep. Breeding improvements of growth and efficiency of production in goats is essential for their use in intensive systems of production.

Effect of Duration of Fasting and a Short-Term High-Roughage Ration on the Concentration of Escherichia coli Biotype 1 in Cattle Feces

A field trial using cattle from a commercial feedlot was conducted to quantify the effect of duration of fasting and a temporary change in ration on the concentration of Escherichia coli biotype 1 in feces. A nested hierarchical design with repeated measures through time was used. Two groups of 20 British × European breed beef steers having reached slaughter weight (mean live weight 685 kg; SD 50 kg) were fed entirely on a high-energy ration typical of that used in the Ontario beef finishing industry or were switched for 4 days onto a high-roughage ration. This was followed by a period of fasting and water deprivation to mimic that which occurs prior to slaughter. Fecal samples were collected at 0, 24, and 48 h of fasting, and for each sample the total presumptive E. coli (biotype 1) CFU/g of feces was enumerated by spiral plating. Estimates of effect for the design factors were obtained by restricted maximum likelihood, and these were compared to robust counterparts obtained from generalized estimating equations. Results indicated that the ration, the duration of fasting, and their interaction had significant effects on total log E. coli concentration in feces. Cattle on the high-roughage ration for four days had a significantly lower initial log E. coli CFU/g of feces compared to cattle on the normal ration, but after 48 h of fasting they had a significantly higher concentration. It is concluded that while a temporary change in ration and duration of fasting does affect E. coli concentration in feces, these changes do not seem large enough to deliver a drastic improvement in beef carcass hygiene should they be incorporated in hazard analysis and critical control point (HACCP) plans for the preslaughter period of beef production.

Organoleptic properties and fatty acid content of muscle from young lambs and hoggets fed grass diets

Sheep production under extensive conditions is environmentally friendly but on upland pastures animals may not reach slaughter weight within one season. However, meat from older ‘hoggets’ will have different organoleptic properties to that from ‘young’ lambs which may affect its acceptability. Whilst prolonged grazing could intensify the highly acceptable flavours associated with grass consumption, which result from a high dietary intake of α-linolenic acid, prolonged fattening can produce less acceptable muttony flavours. Meat quality differences between lambs and hoggets have been compared in this trial by examining 8- and 20- month old Herdwick sheep, produced on grass fells in Cumbria and reputed to produce high quality meat. Grass-fed Suffolk crosses aged 6 months have been used as a control.

Organoleptic properties and fatty acid content of muscle from young lambs and hoggets fed grass diets

Sheep production under extensive conditions is environmentally friendly but on upland pastures animals may not reach slaughter weight within one season. However, meat from older ‘hoggets’ will have different organoleptic properties to that from ‘young’ lambs which may affect its acceptability. Whilst prolonged grazing could intensify the highly acceptable flavours associated with grass consumption, which result from a high dietary intake of α-linolenic acid, prolonged fattening can produce less acceptable muttony flavours. Meat quality differences between lambs and hoggets have been compared in this trial by examining 8- and 20- month old Herdwick sheep, produced on grass fells in Cumbria and reputed to produce high quality meat. Grass-fed Suffolk crosses aged 6 months have been used as a control.

Effectiveness of a pair-gain feeding strategy for individually fed, group-housed finishing pigs.

Crossbred barrows (n = 48) and gilts (n = 12) were used to examine the effectiveness of a pair-gain feeding strategy for individually fed, group-housed barrows. In a pair-gain feeding strategy, barrows were individually restricted to a feeding level at which their growth was similar to the mean growth of gilts with ad libitum access to feed. The purposes of this feeding strategy were to have barrows and gilts reach slaughter weight at the same time and to improve carcass traits of the barrows. At 29.8 +/- .4 kg BW, barrows were assigned to either the pair-gain or the ad libitum treatment. All pigs had free access to feed until they reached 60 kg BW. The experimental period was from 60 to 110 kg BW. The 12 group-fed gilts and 24 individually fed barrows (12 per pen) were also given free access to feed throughout the experimental period. The remaining 24 barrows (12 per pen) were put on a pair-gain feeding strategy. In the pair-gain feeding strategy, the weekly feed allowance of each barrow was based on its measured BW and computed energy conversion ratio and on the mean growth of the gilts. The barrows in the pair-gain treatment grew at the same rate as gilts. The ad libitum intake barrows grew faster (P < .05) and had a poorer energy conversion ratio for production than the barrows in the pair-gain treatment. The total energy conversion ratio, backfat thickness, and lean meat percentage were similar (P > .10) for the two treatments. In conclusion, the pair-gain feeding strategy was effective in achieving similar growth between barrows and gilts. The total energy conversion ratio and carcass traits of the barrows, however, were not improved.

The effect of plane of winter nutrition and sward height on the performance of steers grazing grass/white clover swards

AbstractAn experiment was carried out over 2 years to examine the interactions between two planes of winter nutrition and summer gracing at 5.5 and 7.5 cm compressed sward height on the performance of Limousin X Friesian steers grazing grass/white clover swards. Diets were offered in winter to give liveweight gains of either 0.5 (low) or 0.8 (high) kg d−1. The experiment was repealed over 2 years. Liveweights gains (low 0.50 vs. high 0.84 kg d−1 s.e.d. ±0.044) were achieved in winter 1 and (low 0.55 vs. high 0.91 kg d−1, s.e.d. ±0.041) in winter 2. These differences resulted in animals from the high treatment being 44 and 60 kg head−1 heavier at turn‐out than the low‐treatment animals in years I and 2, respectively. There was evidence of compensatory growth with animals from the low treatment subsequently tending to grow faster than those from the high treatment, with liveweight gains during the period from turn‐out to 84 d of 1.27 vs. 1.18 s.e.d. ±0.65 kg d−1; P= 0–213 and 1.11 vs. 0.95 s.e.d. ±0.062 kg d−1; P=0.015 in summers I and 2 respectively. In general, animals grazing the short sward tended to grow more slowly than those on the tail swards (1.18 vs. 1.27 s.e.d. ±0.065 kg d−1; P= 0.166 and 0.93 vs. 113 s.e.d. ±0.062 kg d−1, P = 0.002) for years 1 and 2 respectively. Growth rates in year 1 were significantly higher than those in year 2. However, increased summer growth rates did not compensate for the differences in live weight established during the winter, and more animals reached slaughter weight in a shorter time from the high than the low treatment. Mean stocking rate on treatments 5.5 and 7.5 over the 2 years were 5.2 and 4.3 animals ha−1: differences were significant in year 2 (P &lt;0.01). The 5.5 cm sward treatment also gave a greater liveweight gain ha−1 than the 7.5‐cm sward treatment in both years with a mean for the two years of 670 vs. 572 kg ha−1 but differences were not significant.

Carcass composition and meat characteristics of two rabbit breeds of different degrees of maturity

Carcass and meat characteristics of rabbits from two synthetic breeds of different size were compared. Breed R had a higher adult weight and reached slaughter weight 1 week before breed V. Sixty rabbits of each breed were slaughtered when they (approximately) reached the Spanish commercial liveweight of 2 kg in order to compare their carcasses and meat quality. The carcasses were measured and retailed according to the norms of the World Rabbit Scientific Association. Breed R had a considerably more developed liver, a less developed hind part, and a more developed thoracic cage. Dissectible fat content was 3.1% and 2.5% of the carcass weight for the breeds V and R, respectively. Meat content was higher in the V breed than in the R breed (53 and 51% with respect to the chilled carcases). The ratio meat bone was better for breed V (2.18 and 2.05, respectively). Muscular fat content, estimated in the meat of one side of the carcass, was higher for breed V. All these differences are related to the lower degree of maturity of breed R at equal weights. Muscular pH, measured on the B. femoris and on the M. Longissimus lumborum at the level of the 5th lumbar vertebra, was the same for both breeds. Colour was measured on the carcass surface and in cuts of the M. Longissimus lumborum. Some colour differences were found for the carcass surface, but not for the meat.

双子の片方の早期離乳が子羊の増体に及ぼす影響

Twenty-two sets of Suffolk ewes and their lambs were maintained indoors for 120 days post partum. Seven ewes giving birth to twin lambs were grouped into two pens, and each set of twin lambs sucked its dam from birth until the group average time of 120 days (T-T). Eight ewes giving birth to twin lambs were grouped into two pens. In these sets of twin lambs, the larger one of each set was weaned at 60 days of age, and the other was left as a single lamb with the ewe (T-S). The lambs weaned at 60 days were grouped into two pens (T-W). Seven ewes giving birth to single lambs were grouped into two pens, and each single lamb sucked its dam from birth until 120 days of age (S-S). Ewes were fed formula feed for raising dairy cattle together with hay to meet the ewe's requirements for CP and TDN (NRC, 1985). T-S ewes consumed less formula feed than T-T ewes after 61 days of lactation. Lambs were creep-fed calf starter together with hay from 10 days of age. Formula feed gradually replaced calf starter from 56 to 60 days of age. From 61 days onwards, all lambs were fed formula feed of 1 kg on an as-fed basis per head per day.The average live weight of T-T lambs reached 51.2 kg at 120 days of age. Hay intake in T-W lambs was higher (p < 0.05) than in T-S lambs, although T-W lambs had a lower (p < 0.05) average daily gain during 61 to 90 days of age. Average live weights at 120 days of age were similar between T-S and T-W lambs. Considerable variation (14%) between individual T-T lambs occurred in live weight at 120 days. A reduction in variation of live weight at 120 days was shown by T-S lambs (5%) and T-W lambs (8%). The average live weight of S-S lambs reached 45.6 kg at 90 days of age.In Japan, lambs are slaughtered over a range of live weights varying from 43 to 53 kg. Lambs weaned at 60 days of age suffered a check in growth at weaning but recovered sufficiently to reach slaughter weight compared to that of twins left with ewes and twins sucking their dams. The technique of early weaning one of a pair of twins can provide a ready means of saving feed for ewes.

Effects of giardiasis on production in a domestic ruminant (lamb) model

Abstract Objective To examine the effects of giardiasis on production and carcass quality, using growing lambs as a domestic ruminant model. Design Randomized block. Animals Giardia-free lambs: 23 in infected group, 24 in control group. Procedure Six-week-old, specific-pathogen-free lambs were infected with Giardia trophozoites; control lambs received saline solution. Clinical signs of infection, body weight, and feed intake were determined for 10 weeks. Carcass weight and quality were determined at slaughter weight of 45 kg. Results Giardia infection persisted from weeks 7 to 16. For 5 weeks after challenge exposure, abnormal feces were more frequently observed in infected lambs. Giardia infection was associated with a decrease in rate of weight gain and impairment in feed efficiency. Time to reach slaughter weight was extended in infected lambs, and the carcass weight of Giardia-infected lambs was lower than that of control lambs. Conclusion Giardiasis has a negative effect on domestic ruminant production. Clinical Relevance Giardiasis in domestic ruminants is an economically important disease, thus necessitating control or elimination of the infection.

Evaluation of the effects of enzootic pneumonia in pigs on weight gain and days to slaughter under New Zealand conditions

The effects of enzootic pneumonia on average daily weight gain and number of days taken to reach slaughter weight was studied in 333 bacon-weight pigs. Each 1% of lung volume affected by enzootic pneumonia was shown to reduce average daily gain by 2.2 grams and increase the numbers of days to slaughter by 0.61 days. The cost of these reductions in performance was calculated to be about NZD 1 for each 1% of lung affected.

Carcass characteristics of equally mature Chios lambs and Damascus kids

Body components, carcass joints based on five anatomical regions, meat qualities and other carcass characteristics were measured on male Chios lambs and male Damascus kids. Kids required a longer time to reach slaughter weight. There were no differences between lambs and kids in dressing percentage, weight of head, kidneys, empty digestive tract and liver. Lambs, however, had less kidney fat, intestinal fat, full digestive tract and feet, but they hed heavier skin and sweet breads than kids. Kids had more dissected meat, moisture, crude protein and ash, but less dissected and chemically determined fat. There were no significant differences between species in carcass length, rib-eye area and meat-to-bone ratio of the whole carcass. Lambs had heavier long leg and lighter shoulder than kids. Meat-to-bone ratio of long leg, shoulder and flank was significantly greater than that of ribs and neck for lambs and kids. In both species, flank had the highest fat, but the lowest protein, moisture and ash, followed by ribs. In kids, neck had the highest CP content followed by long leg, shoulder, ribs and flank: the ranking in lambs was shoulder, long leg, neck, ribs and flank. The best carcass joint for estimating total carcass CP, fat, and ash content was long leg and for moisture content shoulder. Carcass moisture was negatively correlated with fat but positively with CP and ash contents. It is concluded that Damascus kid meat is leaner than that of Chios lamb meat but the latter deposits its fat in a way that it may be accepted by the consumer. Dissection and/or chemical analyses in one carcass joint gives a good indication for the whole carcass. Neck, a region comprising a small proportion in the whole carcass and of second quality, can be used for predicting the CP, ash and fat content in the whole carcass.

An Epidemiologic and Economic Study of Respiratory Diseases in Two Conventional Danish Swine Herds. I: Prevalence of Respiratory Lesions at Slaughter and Their Effects on Growth

A total of 578 slaughter pigs from 2 Danish conventional farrow-to-finish operations (Herds A and B) were followed from an age of 14 days to slaughter. Pigs were weighted at 3 weeks intervals and at slaughter and an extended post mortem examination of the plucks was done. Comparison of growth rates in pigs with and without specific types of lesions by the t-test and those with multiple lesions with regression models demonstrated that Mycoplasma-like pneumonia, complicated pneumonia, anterio-ventral pleuritis, fissures and atrophic rhinitis significantly reduced mean daily gain and increased the time required to reach slaughter weight. The total impact of the lesions in Herd A was an estimated reduction in mean daily gain of 27 grams and a 2 day increase in the interval from 14 days of age until slaughter (MDG14). Decreases in MDG14 in Herd B were more substantial, 98 grams and 16.7 days. Reductions in mean daily gains during the interval from the fourth weighing until slaughter were 31 grams in Herd A and 137 grams in Herd B. Chronic dorso-caudal and parietal pleuritis, without other lesions present, had no significant adverse effects on growth rates in either herd. Interactions between lesions did not significantly alter the estimates. The R2 values obtained for the regression models showed that the presence, absence or extent of lesions at slaughter explained only 13-27% of the variations in growth rates in the 2 herds.

Evaluation of the growth performance and carcass characteristics of commercial pigs produced in Quebec

Data for a total of approximately 2900 commercial pigs tested in 12 trials from 1987 to 1990 at the Beaumont test station in Quebec were used to determine the effect of sex, sire breed, cross type and parity number of the dam on growth performance and carcass characteristics. Pigs were housed four to a pen and were fed commercial diets. Feed intake and growth rate were measured during the test, and carcass measurements were taken at slaughter and at 24 or 72 h following slaughter. Castrated males ate more per day, had a better gain and reached slaughter weight (96.4 ± 5.6 kg) at a younger age than gilts. Gilts had a better carcass yield and were leaner than castrated males. Commercial pigs sired from Duroc or Duroc–Hampshire boars had a growth performance superior to that of pigs sired by Landrace, Yorkshire or Hampshire boars. Progeny from Duroc or Duroc–Hampshire boars also produced carcasses with less loin fat, a thicker loin muscle, a higher estimated lean yield and a better classification index. Pigs from three-way crosses had a higher average daily gain and a better feed conversion than pigs from other types of crosses (single, backcross, four-way, synthetic and purebred), and they reached market weight at a younger age. Most carcass characteristics were also affected by the type of cross, but no specific type of cross was clearly superior to the others for the various variables studied. An increase in parity number of the dam caused a gradual decrease in growth performance, except for pigs from parity six, which presented the best results. There was also a linear decrease in loin muscle thickness, estimated lean yield and classification index and a linear increase in loin fat thickness with increase in parity number of the dam. Key words: Pig, growth performance, carcass composition

Feed efficiency, carcass characteristics, and sensory quality of lambs, with or without prolific ancestry, fed diets with different protein supplements1

Data were collected on 130 intact male lambs fed diets based on roughages supplemented with fish meal, soybean meal, or corn gluten-blood meal and slaughtered at 43 kg live weight. A nonsupplemented group served as a control. The lambs represented Romanov (R), Finnsheep (F), a new breed developed in Canada (DLS), Coopworth (C), and Suffolk (S), three first crosses of DLS with R, F, and Booroola Merino (B), and their backcrosses to DLS. Supplemented lambs consumed 16 to 22% less (P less than .05) silage than control lambs. Average daily gains of lambs fed fish meal (226 g) and corn gluten-blood meal (217 g) were higher and feed conversion ratio (4.99 and 5.11) lower than that of lambs fed soybean meal (189 g and 5.48) or control (186 g and 5.76) diets (P less than .05). The cost of feed per kilogram of gain or per kilogram of lean produced was similar in the four treatments but was between C $.23 and .65 cheaper in the protein-supplemented groups when the number of days to reach slaughter weight was considered. The effect of diet on carcass traits and meat quality were minimal. Meat of lambs fed the three protein supplements was less juicy than that of control lambs. With a few exceptions, most of the significant differences among genetic groups in growth, carcass, and sensory traits were mainly between prolific (R and F) and meat-type breeds (C, S, and DLS). Gain in weight was highest in S lambs (199 g/d), but F and R first crosses were the youngest at slaughter (196 and 198 d). The F lambs had higher dressing and kidney fat percentages than meat-type breeds. The DLS lambs had the largest longissimus muscle area (14.0 cm2), whereas C had the smallest (10.7 cm2). The B crosses had larger longissimus muscle area than R and F crosses. The R lambs had more lean and less fat in the 12th rib, whereas C lambs had the lowest lean and a high bone percentage. The toughest and the most tender roasts were those of R and B crossbred lambs, respectively. Roasts from F lambs had the most intense lamb flavor.

Effect of Vitamin E Supplementation on Weight Gain, Immune Competence, and Disease Incidence in Barley-Fed Beef Cattle

The aim of the study was to investigate whether vitamin E supplements in larger amounts than recommended could reduce incidence of disease, improve immune competence, and increase rate of weight gain of conventionally barley-fed beef cattle.Mean daily intake of vitamin E by individual calves in the experimental group was 200mg during the first 2 mo, 400mg during the next 2 mo, and 600mg during the rest of the period. Corresponding daily intakes of vitamin E for the control group were 50, 100, and 150mg.Mean plasma vitamin E of the experimental group increased from .49mg/L at the start of the trial to 2.03 mg/L at the end, but that of the control group was lower at the end (.36 mg/L) than at the beginning (.53 mg/L). No significant differences were observed between the groups concerning incidence of disease or magnitude of lymphocyte stimulation.The results indicated that there was a surprisingly poor biological availability of the dietary vitamin. Therefore, a comparison in reality was made between calves with inadequate and normal vitamin E status. The differences in daily BW gain and time to reach slaughter weight thus probably were effects of the low vitamin E status rather than positive effects of additional vitamin in the diet.

Effect of early weaning one lamb in a triplet lamb rearing system

ABSTRACTThirty-seven Cambridge (C) and Suffolk (S) × C ewes and their lambs were housed and penned individually in family groups for 35 days post partum and then grazed on pasture until the lambs reached slaughter weight. Lambs were reared as twins (TR-TW). The lambs weaned at 35 days were artificially reared and formed the TR-AR group.Dry matter intake of the complete diet and hay offered ad libitum during the housing period was unaffected by rearing type. TR-TR and TR-TW ewes produced more milk at 10 days than TW-TW ewes, 4·4 and 4·2 v. 3·6 (s.e.d. 0·257) kg/day. From 35 days onwards the decline in milk yield tended o t be greater in the TW-TW and TR-TW ewes which also gained more condition than TR-TR ewes, 0·33 and 0·37 v. 0·01 (s.e.d. 0·139) of a score.TW-TW lambs grew faster than TR-TW and TR-TR lambs during the housed period, 336 v. 295 and 292 (s.e.d. 9·8) g/day but after 35 days TR-TW, TR-AR and TW-TW lambs had similar growth rates, 348, 350, and 348 (s.e.d. 14·2) g/day respectively whereas TR-TR lambs grew less quickly at 310 g/day. Forty-two male lambs were slaughtered. TR-AR lambs had a higher killing-out proportion and carcass fat content than naturally reared animals. In the latter group carcass fat content was negatively related to time reared as triplets and the kidney knob and channel fat weight was significantly lower in the TR-TR group. Crossbred lambs grew faster, had a higher killing-out proportion and greater weight of m. longissimus dorsi and m. psoas major in the half carcass.It is concluded that weaning one lamb at 35 days provides a suitable alternative system for rearing triplets and that it is possible to produce good quality carcasses with some desirable reduction in fat content from lambs reared as triplets throughout their life.