bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth and carcass characteristics of weaned single-suckled calves slaughtered on achieving slaughter condition or 8 or 16 weeks later
Authors: Broadbent P. J.
Published: September 2010

1. Weaned single-suckled calves (castrates) were housed at 260·7 kg live weight. Six genotypes, all two- or three-way crossbreds, were represented. A diet of bruised barley, wet distiller's grains, swedes and grass silage was offered until the required minimum live weight (363 kg) and body composition was reached. The cattle were then slaughtered (treatment A), or retained for 8 (treatment B) or 16 weeks (treatment C). During the period when treatment B and C animals were retained their diet was 53% bruised barley and 47% wet distiller's grains offered ad libitum.

2. Live weights at slaughter were 418·2, 458·6 and 496·1 kg (P < 0·001), carcass weights 240·5, 266·2 and 295·7 kg (P < 0·001), and killing-out percentages 57·5, 58·1 and 59·6 (P<0·01) for treatments A, B and C respectively. Daily live-weight gain did not decline during the 8 or 16 weeks cattle were retained on treatments B and C.

3. Retaining the cattle to slaughter points B and C caused increases in the percentage of low-value joints in the carcass, carcass fat percentage, dry matter and fat contents of the dissected m. longissimus dorsi; and decreases in the percentage of high-value joints, carcass lean and bone percentage, crude protein and ash contents of m. longissimus dorsi. The carcass composition was 55·6, 53·5 and 51·4% lean (P<0·001); 30·7, 33·3 and 36·2% fat (P<0·001); 13·7, 13·2 and 12·4% bone (P< 0·001) for treatments A, B and C respectively.

4. The results are discussed in relation to the choice made by beef producers between slaughter and retention of cattle which have reached suitable live weight and condition for marketing.
A note on the use of condition scoring in commercial sheep flocks
Authors: Pollott G. E. , Kilkenny J. B.
Published: September 2010

Three aspects of body condition scoring in commercial sheep flocks were examined. Ewes in 44 flocks were condition scored when the rams were introduced to the flock and their subsequent lambing performance was recorded. The pooled regression coefficient obtained for the relationship between individual ewe condition score and litter size was 0·29±0·0243 with a squared correlation coefficient of 1·96%.

Between flock differences accounted for 57% of the variation in ewe condition score. Within the breeds recorded average flock condition score at mating was related to the number of live lambs born per 100 ewes mated. This relationship is shown for several breeds of ewe. A further 27 flocks were involved in a trial to evaluate the effectiveness of a specific use of condition scoring. Ewes were scored 6 to 8 weeks before mating and in 12 flocks the ewes in poor condition were given an improved plane of nutrition. These ewes showed an improvement of 12 lambs born per 100 ewes mated over ewes not given better nutrition.
Breed differences in body composition of equally mature sheep
Authors: McClelland T. H. , Bonaiti B. , Taylor C. S.
Published: September 2010

Sheep from the Soay, Finnish Landrace, Southdown and Oxford Down breeds were serially slaughtered at about 40, 50, 60 and 70% of their estimated mature body weight. Breed and sex comparisons were made at these degrees of maturity. Large differences were found in the weight of muscle, fat and bone, total muscle ranging from a mean of 3·3 kg in the Soay to 13·0 kg in the Oxford Down; the corresponding range for dissected fat was 1·2 to 9·2 kg.

Most of the breed and sex differences observed at the same degree of maturity disappeared when expressed as a percentage of body or carcass weight. Thus both sexes had almost the same body and carcass composition in terms of fat, muscle and bone percentage. There were breed differences in fat percentage, with the Soay significantly less fat than the other breeds. Total muscle as a percentage of body weight was remarkably close to 28·5% in all breeds in both sexes, and at all four stages of maturity.
Prediction of the energy requirements for growth in beef cattle. 2. Hereford × British Friesian steers given dried grass or barley
Authors: Webster A. J. F. , Smith J. S. , Crabtree R. M. , Mollison G. S.
Published: September 2010

1. Hereford × British Friesian castrate male cattle, growing from about 80 to 500 kg, were given equal amounts of metabolizable energy (ME) from dried grass pellets or from a pelleted diet of barley and a protein supplement. Two animals on each diet were fed close to appetite (High) and two at a level mid-way between maintenance and appetite (Medium). The rations for all animals were reduced to approximately maintenance for 4 weeks on three occasions equally spaced throughout the experiment. Measurements of energy and nitrogen balance were made for each animal at intervals of 6 to 8 weeks. Total body-water content was estimated from D20 dilution at intervals of 110 kg live weight.

2. Values for the metabolizability of the gross energy of the dried grass and barley/protein diets were 0·55 and 0·67.

3. Metabolic heat production during growth was closely related to body weight to the power 0·75. Predicted basal metabolism was 395 kJ/kg 0·75 per 24 hr.

4. Estimates of the net efficiency of utilization of ME for growth were unaffected by small variations in the exponent of W used to describe the effect of body size on heat production. Both diets were utilized above maintenance with a net efficiency close to 0·62.

5. Nitrogen balance trials seriously overestimated nitrogen retention. Gains in fat-free body mass estimated from D2O dilution were combined with calorimetric measurements of energy retention to predict the relationship between energy retention and weight gain. The agreement between observed and predicted live-weight gain was good at the lower body weights and on the lower ration. For fatter animals eating the high ration at higher body weights, live-weight gains were less than predicted.
A note on the efficiency of different forms of comparison among foreign breeds
Authors: Smith C.
Published: September 2010

Expressions are given for the variance of estimates of breed differences for direct and indirect comparisons among foreign breeds, using either purebreds or crossbreds. These expressions allow for planned genetic relationships among the groups tested.
Concentrations of plasma hormones in relation to placental retention in Karan Swiss cows during and after induction of parturition with dexamethasone and stilboestrol dipropionate
Authors: Prakash B. S. , Madan M. L.
Published: September 2010

Five Karan Swiss cows were allowed to calve spontaneously and served as controls (Group A), while another 10 were induced to calve about 1 month prior to expected term using either 25 mg dexamethasone alone (Group B) or 25 mg dexamethasone in combination with 25 mg stilboestrol dipropionate (Group C). Blood samples were collected prior to, and for 50 days following, parturition for subsequent hormone analysis, and observations were made on the occurrence of retained placentae.

Parturition was successfully induced in all treated cows within 72 h of drug administration. Placental membranes were retained for 24 h in all treated animals and were manually removed in the farm veterinary clinic. No incidence of placental retention occurred in control cows.

Mean plasma oestradiol-17β in control cows showed a gradual rise from days 30 to 5 pre partum, followed by a sharp increase to peak value 1 day before calving. The rise in mean oestradiol-17β levels in the 2 days before parturition in controls was significantly greater than that recorded for the treated animals. A precipitous drop in plasma oestradiol-17β level occurred following parturition in all groups, with the levels staying low for the rest of the sampling period. Drug administration to animals in groups B and C resulted in a rapid and significant drop in plasma progesterone concentrations to a level similar to that for control animals at parturition. Subsequently, the plasma progesterone remained low in all treatment groups. Mean plasma cortisol levels showed a significant but transient increase at calving in control cows, but were suppressed for at least 48 h following drug administration in treated cows before exhibiting a rebound phenomenon to reach high values after calving.

It is concluded that for normal placental expulsion, oestradiol-17β levels are more critical than progesterone, and that the rise in oestradiol-17β and fall in progesterone levels pre partum must be gradual.
Effect of fermentation on compositional changes of antibiotic milk and performance of calves fed fermented antibiotic milk
Authors: Hadjipanayiotou M. , Georghiades E.
Published: September 2010

Compositional and acidity changes in fermented normal or antibiotic milk, and the effects of feeding jch milk on the growth, food conversion efficiency and overall health of dairy calves were studied, Type of milk (normal or antibiotic) did not significantly affect pH, lactose, crude protein, fat and free (H3—N content of milk. Lactose content and pH values decreased with time whereas free NH3—N lcreased. Higher room temperatures were associated with lower pH; values below 5 were obtained after weeks of fermentation in winter, 2 weeks in spring, 1 week in autumn and less than 1 week in jmmer. Overall pH values and lactose content declined until week 4 and remained constant thereafter, calves fed fermented antibiotic milk gained less weight from birth to weaning than those on fresh milk, put post-weaning growth rates were similar. Incidence of scouring was higher among calves fed antibiotic lilk, but no deaths occurred. Milk intake was similar, and consumption of dry food (pre and post eaning) differed slightly.
Inter-age correlations of body weight, weight gain and food intake within and between breeds of cattle
Authors: Thiessen R. B.
Published: September 2010

In a multibreed experiment, 292 heifers from 25 British cattle breeds were fed a standard pelleted diet ad libitum from 12 to 72 weeks of age. Inter-age correlations involving body weight, weight gain, average daily food intake and cumulated food intake were measured across traits at the same age and within and across traits at ages separated by an interval of 12, 24, 36 and 48 weeks. Within-breed correlations were phenotypic but between-breed correlations were genetic.

The between-breed inter-age correlations involving body weight, cumulated intake and average daily intake were all very high (range 104 to 0·94) and declined only gradually as the intervening age interval increased from 12 to 48 weeks. Inter-age correlations involving weight gain were lower but usually above 0·7. The within-breed correlations by contrast were invariably lower and declined much more rapidly as the age interval increased. Although the between-breed and within-breed correlations differed in magnitude there was a similarity in their overall pattern.

For breed samples, body weight at young ages provided very accurate rankings at later ages for body weight, cumulated intake and average daily intake. Body weight was almost as reliable as food intake itself for predicting cumulated intake.

For individuals within breeds predicted rankings at later ages were not very accurate for body weight or cumulated intake and they became worse as the age interval increased. Neither weight gain nor average daily intake could be predicted with any reliability.

Inter-age correlations while dependant on age interval did not depend on age itself in the case of body weight and cumulated intake, although they were age-dependant for weight gain and to a lesser extent for average daily intake. Reciprocal correlations between body weight and cumulated intake were very symmetrical whereas those involving weight gain and daily intake were asymmetrical.
A note on the fleece characteristics of Oxford Down sheep
Authors: Ryder M. L. , Walker M. F.
Published: September 2010

Fleece measurements were made in a closed flock of Oxford Down sheep being maintained by random mating. The original 20 ewes were sampled in 1970 and another 20 of the 30 ewes were sampled in 1980. Staple length, mean fibre diameter and secondary/primary follicle ratio were similar at the two sampling times. There were more inactive follicles in 1980 and more follicles with multiple fibres, but the differences were not significant. The appearance of some medullation and pigmentation in 1980 could have an environmental rather than a genetic cause. Follicles intermediate between primaries and secondaries were observed, and in all fibres the bilateral structure was clearly visible.
A note on the effect of exposure to a boar on the development of the reproductive system of immature gilts
Authors: Walton J. S.
Published: September 2010

Eight groups of six Yorkshire gilts were either exposed (BE) or not exposed (NE) to a mature boar at 160 days of age. These groups of gilts were slaughtered at 160, 165, 170 and 180 days of age for examination of their reproductive tracts.

NE gilts remained pre-pubertal from 160 to 180 days, with uterine weights of 121·6 g and 148·0 g respectively. Boar exposure induced ovulation in three out of five gilts by day 170 and in five out of six gilts by day 180. Uterine weight increased in BE gilts from 121·6 g at 160 days to 343·6 g, 298·0 g and 535·6 g by days 165, 170 and 180 respectively. This was accompanied by an increase in the number of large ovarian follicles (≤ 6 mm in diameter) from 0 at 160 days to 9·0 at 165 and 4·2 at 170 days.

These results confirm the potent stimulatory effect of boar exposure on puberty in gilts and suggest the use of ovarian status and uterine weight at slaughter 10 days after stimulation as a reliable indicator of the response of the pre-pubertal gilt to environmental change.
A new approach to the mathematical formulation of lactation curves
Authors: Morant S. V. , Gnanasakthy A.
Published: September 2010

Six alternative lactation curves were derived by considering the proportional rates of change in milk yield during lactation. Experimental data showed that rates of change do not necessarily fall to a constant value in mid and late lactation. This accounts for the systematic lack of fit reported by several authors using the derivative of the incomplete gamma function, whose second derivative has a horizontal asymptote. Curves whose derivatives are not restricted in this way described patterns of milk yield in first to third lactation animals more closely. Some statistical properties of their parameters have been examined. The curve loge (y) = a - bt'(1 + kt') + ct'2 + d/t, where t is days since calving, t' = t – 150, A: is a constnat and a, b, c and d are parameters to be estimated, is recommended. This curve was also fitted to yields of milk fat, protein and lactose.
A deterministic model for the optimization of dairy cattle breeding based on BLUP breeding value estimates
Authors: Meuwissen T. H. E.
Published: September 2010

A deterministic model was developed to examine the optimization of open nucleus breeding schemes in order to maximize the rate of genetic response in dairy cattle. By changing the parameters, the model was able to simulate both a closed nucleus and a progeny testing scheme. The model implicitly optimized the generation interval and the selection across tiers by means of truncation across age classes and tiers respectively. The effects of size of the progeny test group and the nucleus size were assessed by comparing alternative plans. It is possible to optimize a breeding plan given the reproduction rates of the animals, the availability of different sources of information, the age distribution of the animals (survival rates) and the phenotypic and genetic parameters of the trait.

The steady state selection response was assessed by calculating the genetic progress year after year until it stabilized. The genetic gain was corrected for the effects of reduced variances due to previous selections and increased variances due to genetic differences between parental age classes.

In an example, the model was used to predict the improvement in milk yield in a closed artificial insemination breeding scheme. The genetic gain of a conventional progeny testing scheme was about one-third lower than the genetic gain of the optimized breeding plan. The variance reduction due to selection decreased the steady state genetic gain by a factor 0·3
Effects of recombinant DNA-derived bovine somatotropin on growth, carcass characteristics and meat quality in lambs from three breeds
Authors: Sinnett-Smith P. A. , Woolliams J. A. , Warriss P. D. , Enser M.
Published: September 2010

Purebred lambs from three breeds (East Friesland, Oxford and Texel) were fed to appetite and treated with recombinant DNA-derived bovine somatotropin (BST) at 0·05, 0·10 or 0·20 mg/kg per day or a placebo between 19 and 27 weeks of age.

BST maintained growth over the later stages of treatment but did not affect average daily live-weight gain over the whole treatment period. Food intake was decreased and food conversion efficiency was improved by BST treatment. However, carcass weight and killing-out proportion were decreased by BST treatment in all breeds. Consistent breed differences were observed. Oxford lambs had higher live weights and carcass weights than the other breeds but no breed × treatment interactions were apparent. Ultrasonic backfat depth (mean of measurements at 13th rib and 3rd lumbar vertebra) was reduced by BST treatment in the Oxford (the fattest) and Texel lambs but not in the East Frieslands (the leanest). Ultrasonic muscle depth was not affected by BST; East Friesland lambs had considerably smaller muscle depth than the other breeds.

In the loin joint, BST decreased fat cover and subcutaneous fat proportion and increased longissimus dorsi proportion. There were also marked breed differences with Oxfords fatter than the other breeds. BST treatment did not affect any of the meat quality indicators but some differences between breeds were apparent in ultimate pH and colour of the muscle. Fatty acid composition of the subcutaneous fat was affected by breed but not by BST. East Friesland lambs had higher concentrations of unsaturated and branched chain fatty acids than the other breeds.

A mammogenic response (increased mammary development and some secretory activity) to BST was observed in some female East Friesland and Texel lambs but not in Oxford lambs.
Low glucosinolate full-fat rapeseed meal in the diets of early-weaned piglets
Authors: Gill B. P. , Taylor A. G.
Published: September 2010

The potential of using low glucosinolate full-fat rapeseed meal (FFR) in the diets of early-weaned piglets was investigated in this experiment. FFR (containing 17 (xmol total glucosinolates and 2·8 mg erucic acid per g of whole seed) was used on an isonitrogenous basis at either 200 g<kg or 400 g<kg to replace full-fat soya-bean meal. Four replicates of three contemporary pen groups of 10 piglets weaned between 3 and 4 weeks of age were randomly allocated at a mean initial weight of 8·41 (s.e. 1·105) kg to the three dietary treatments. The experimental diets were given for 3 weeks. Inclusion of FFR significantly depressed food intake, daily live-weight gain and food conversion. There were no significant differences between the performance of piglets given either 200 or 400 g FFR per kg. Intakes of the diets containing FFR per unit of metabolic body weight as a proportion of the control diet decreased from about 0·85 to 0·75 from the 1st to the last week of the feeding period. This suggested that the acceptability of diets containing FFR decreased with time, possibly due to the presence of unpalatable and perhaps antinutritive factors which may include glucosinolates although present at relatively low concentrations. It was concluded that the feeding value of FFR would need to be improved by development of oilseed rape varieties with much lower levels of glucosinolates.
A note on the inclusion of the antibiotic Actaplanin in the diets of lactating dairy cows
Authors: Abubakar M. M. , Rowlinson P.
Published: September 2010

Actaplanin, a complex of glycopeptide antibiotics produced by Actinoplanes missouriensis, was investigated as a performance enhancer when incorporated in the diet of lactating dairy cows at the rate of 960 mglday. In a trial with autumn-calving cows over two successive lactations, the milk yield of animals given diets incorporating Actaplanin (no. = 132 lactations) showed only a small (proportionately +0·038), nonsignificant increase in milk yield over the controls (no. = 121 lactations). Overall, there were no significant differences in milk composition, cow body weight or condition score changes, mastitis cell counts or in the majority of blood metabolites.
The effect of hexoestrol implants on sucking and weaned lambs fattened on farms in the north-east of Scotland
Authors: Preston T. R. , Greenhalgh Isoline , MacLeod N. A.
Published: September 2010

1. 768 lambs on fourteen farms in the north-east of Scotland were divided into a control group and groups receiving two 5 mg., three 5 mg., two 7·5 mg., and one 15 mg. pellet of hexoestrol.

2. On every farm the mean rate of live-weight gain of the treated lambs was greater than that of the controls.

3. There appeared to be very little difference between implantations of two 5 mg., three 5 mg. and two 7·5 mg. pellets of hexoestrol but on four farms where a direct comparison was made one 15 mg. pellet was slightly inferior to three 5 mg. pellets.
The effect of plane of nutrition during rearing on growth, production, reproduction and health of dairy cattle. I. Growth to 24 months
Authors: Crichton J. A. , Aitken J. N. , Boyne A. W.
Published: September 2010

1. Eighteen pairs of one-egg and 6 pairs of two-egg twin calves were used in a balanced incomplete block design to examine four systems of rearing: (1) a continuous high plane of nutrition from birth to first calving (HH); (2) a high plane for the first 44 weeks followed by a low plane until 2 months before calving (HL); (3) a continuous low plane until 2 months before calving (LL); and (4) a low plane to 44 weeks followed by a high plane to first calving (LH). All animals were fed on a high plane during the two months before calving.

2. Mean daily consumptions of DM, TDN, S.E. and DCP are given and the net energy intakes compared with a recently recommended standard.

3. At 44, 80 and 104 weeks of age there were highly significant differences between the groups in all weights and measurements due to treatment. Low-plane feeding retarded the growth of the skeleton to only a limited extent as compared with live-weight. After the changeover, animals on the HL system lost much of the advantage in body measurements they had gained over those fed on a continuous low plane.

4. All groups reached sexual maturity at the same stage of physical development but at different ages. The HL animals were the slowest to attain maturity indicating that as with growth the changeover from a high plane to a low plane of nutrition had had an adverse effect.

5. Low-plane animals on poor hill pasture made better growth than their mates on good arable pasture. Evidence is presented, however, to show that part of this greater growth in live-weight was due to increased ‘fill’.
An initial investigation on the effects of low level feeding of hydroxyzine dihydrochloride on growth, endocrines and carcass measurements of fattening cattle
Authors: Preston T. R. , Aitken J. N. , MacLeod N. A. , McDiarmid A.
Published: September 2010

In an initial experiment, cattle receiving 5 mg. hydroxyzine dihydro-chloride daily gained 12·7% faster and manifested 12·0% better feed conversion ratio than the control, but these effects were not statistically significant under the conditions of the experiment. Carcass quality and endocrines were not affected by hydroxyzine feeding.
A comparison of whole milk with buttermilk in the rearing of calves for veal. 2. Slaughter and carcass composition data
Authors: Barton R. A. , Kirton A. H.
Published: September 2010

1. Two groups of Friesian calves, one group of 10 reared on whole milk and the other group of 9 changed gradually from whole milk at 21 days of age to a full diet of reconstituted buttermilk powder at 29 days of age, were slaughtered at a live-weight of approximately 203 1b. Data obtained at slaughter showed a highly significantly heavier weight of omental fat from the calves of the whole milk group, and a significant difference in the weight of the unemptied intestinal tract in favour of the buttermilk group.

2. One side of each carcass was dissected by anatomical joints into the primary tissues; bone, muscle, fat, and tendon and waste. The absolute proportional weight of the dissectible fatty tissues and the weight of kidney and channel (pelvic) fat were statistically highly significantly heavier in the carcass sides of the calves reared on whole milk. The percentage of muscular tissue in the sides of the buttermilk reared calves was significantly higher than for the sides in the other group.

3. The chemical composition of the dissected muscular tissue revealed highly significant differences in fat (ether extract) and a significant difference in water percentage in favour of the carcass sides of the calves reared on whole milk.

4. The chemical composition of the dissected fatty tissue showed statistically highly significant differences in favour of the calves reared on whole milk for the items: water weight and percentage, fat weight and percentage, protein weight, and ash weight. The buttermilk group had in their dissectible fatty tissue a highly significantly greater proportion of water and protein.

5. The dissectible components of the individual joints showed: significantly heavier weight of fatty tissue from the leg, loin, pelvis, 9–10–11 rib cut, thorax, and shoulder of the left sides of the calves reared on whole milk. The weights of the dissectible muscular tissue of the loin and the rib cut were significantly heavier for the buttermilk-reared calves.

6. Cutting-out data on a limited number of sides showed no consistent differences between groups.

7. The meat trade did not differentiate against the buttermilk-fed calves despite their lower fat content. The high muscular tissue content at 65–68% makes veal a very desirable product.
Copper sulphate as a growth stimulant for pigs: effect of level and purity
Authors: Lucas I. A. M. , Livingstone R. M. , McDonald I.
Published: September 2010

Two 2 × 4 factorial experiments each involved 8 litters of 8 pigs, one pig from each litter being allocated to each treatment. Diets containing supplements of a commercial grade of copper sulphate were compared with others containing Analar (Experiment 1) or micro-analytical reagent grade copper sulphate (Experiment 2). Four levels of each of two grades of CuSO4.5H2O, providing 16, 62, 125 or 250 p.p.m. Cu in the diets, were given in each experiment.

The pigs were put on experiment at 8—9 weeks of age and most were slaughtered as their individual weights reached about 200 lb. The exceptions were 4 litters in Experiment 1 which were taken off experiment at that weight but not slaughtered. The pigs were fed in individual compartments, meal allowances being determined from a fixed scale based on live-weight.

Purity of copper sulphate did not affect growth rate, feed conversion efficiency or carcass measurements in either experiment.

Response to level of copper sulphate between about 45 and 100 lb. liveweight differed somewhat between experiments. In Experiment 1 pigs receiving 125 or 250 p.p.m. in the diet grew 4 or 9% faster and had better feed conversion efficiencies than those receiving 16 or 62 p.p.m. Cu. In Experiment 2, pigs receiving 62, 125 or 250 p.p.m. Cu all grew about 4–5% faster and had 1–5 % better feed conversion efficiencies than those receiving 16 p.p.m. Cu, but the effect on feed conversion efficiency was not statistically significant.

Increase in copper sulphate above the trace level supplying 16 p.p.m. Cu in the diet had no effect on growth rate or feed conversion efficiency between 100 and 202 lb. live-weight or on killing-out percentage or carcass measurements.

Comparison of the results with those from a previous experiment showed that in pigs fed according to a fixed scale the greatest consistent increases in growth rate and feed conversion efficiency have occurred with copper sulphate as 0·1% of the diet, giving 250 p.p.m. Cu. This supplement has only improved performance between 100 and 200 lb. live-weight in one experiment out of five.
The yields of cuts from Wiltshire bacon sides in relation to length and other carcass measurements
Authors: Harrington G. , Pomeroy R. W.
Published: September 2010

1. Judges' scores for the ‘proportion of cuts’ of bacon sides were related to the length and to the ratio of the length and depth of the sides, but not to the weight of the fore-end.

2. In two investigations involving six hundred and eighty sides of bacon, length showed little relation to the yields of the major wholesale cuts or to measures of value based upon them, although in one analysis longer sides tended to have lighter fore-ends. Fatter sides tended to be heavier in the back and lighter in the fore-end and gammons than leaner sides of the same weight.
Nutritional factors affecting lean meat production in cutting pigs
Authors: Bellis D. B. , Taylor J.
Published: September 2010

A series of trials were designed to determine the slaughter weight of cutting pigs at which lean meat production is most economical, and to investigate nutritional factors which affect lean meat onput in cutting pigs of about 260 lb. live-weight. The trials involved about 1100 pigs and ad lib. feeding was adopted from weaning to slaughter.

In the first trial, pigs were fed on various diets to 300 lb. live-weight. The diets differed in the amount of protein fed during the 90–180 lb. growth period, and the most economic growth was made by feeding a high protein (17 %) diet to 140 lb., or a medium protein (14 %) diet to 180 lb. followed by a cereal-mineral diet thereafter to 300 lb.

Animals were slaughtered and dissected at various live-weights between 90 and 300 lb. and it was found that killing-our percentage, the percentages of usable meat (lean plus fat) and of fat, increased with carcass weight. The increase in fat deposition was mainly at the expense of the non-edible parts of the carcass. Onput of lean and increase in area of eye muscle occurred throughout the range.

Total food requirements, expressed as pounds of food, calories of gross energy or pounds of protein, per pound of usable meat produced decreased as slaughter weight increased. The cost of food required to produce a given quantity of lean meat was least when pigs were slaughtered between 240 and 260 lb. when the commercial value of the remainder of the carcass was taken into account.

The second trial investigated the effect of two levels of protein and mineral supplementation of cereals during the 140–260 lb. growth period of heavy pigs. Correct mineral supplementation of cereals was essential because, although lean meat production was not increased, the cost of food required to produce it was less. The lower protein diet had no effect on growth or carcass composition, but the higher protein diet increased the lean meat content of carcasses and decreased the amount of food required to produce it. The production of the extra lean meat, however, was not economical because of the cost of the high protein diet.

The third trial showed that replacement of barley by wheat during the 140–260 lb. growth period led to carcasses having less lean meat and to higher feed requirements. This is probably connected with the high energy content of wheat as compared to barley.
Further observations on the relative influence of birth weight and creep-feed consumption on the 3- and 8-week weights of sucking pigs
Authors: Lodge G. A. , McDonald I. , MacPherson R. M.
Published: September 2010

1. Data from the first 3 litters of each of 21 Wessex Saddleback sows were analysed on within-Utter, between-litter/within-sow and between-litter/ between-sow bases.

2. There were highly significant differences between sows in the mean weight of their pigs at birth, 3 and 8 weeks of age; between litters of the same sow there were no significant differences at birth or 8 weeks but pigs in third litters were significantly lighter than those of the first and second Utters at 3 weeks of age. There was a significant increase in number born but not in number weaned from first to third litters.

3. Within litters, the variation in 3-week weight accounted for by variation in birth weight was 30% in first litters, 48% in second litters and 45% in third; respective relationships between birth weight and 8-week weight were 14, 27 and 26%. Between litters of the same sow, differences in mean birth weight accounted for 50 % of the difference which occurred in 3-week weight and for 26 % of the difference in 8-week weight. Differences in mean creep-feed consumption accounted for 18% and differences in mean 3-week weight for 44% of the differences which occurred in weight at weaning. Between litters of different sows, the variation in birth weight accounted for 48% of the variation in 3-week weight, and 8% of the variation in 8-week weight. Differences in creep-feed consumption accounted for 36% and differences in 3-week weight accounted for 26 % of the difference in weight at weaning.

4. Season of birth had some effect on weaning weight due in part to an effect on creep-feed consumption. There was a negative correlation between birth weight and mortality and a positive correlation between mortality and Utter size.
Further studies of hexoestrol implantation of Blackface wether lambs
Authors: Armstrong R. H. , Cameron A. E.
Published: September 2010

1. In the summer of 1958, 15 mg. of hexoestrol was administered to Blackface wether lambs in one of the following ways; 5 mg. before weaning followed by two 5 mg. tablets at weaning, three 5 mg. tablets at weaning, and thirdly a single 15 mg. tablet at weaning. In a further series of experiments in 1959 the effect of both raising the pre-weaning implantation to 10 mg., and the total hexoestrol dosage to 20 mg. was studied.

2. Suckled lambs implanted with 5 mg. of hexoestrol at the milk clip gained significantly more in live-weight (18%) up to weaning in 1958 than did untreated lambs; in 1959 the difference was only 11%.

3. Between weaning and the end of the trial all treatments with the exception of that in which hexoestrol dosage was raised to 20 mg. showed a very highly significant increase in live-weight gain over untreated lambs, the increases ranging from 26 % to 54%.

4. In neither year was the overall gain in live-weight from pre-weaning to the end of the trial significantly increased by implanting part of the hexoestrol dose prior to weaning.

5. Live-weight gain of the lambs was not significantly increased when three 5 mg. tablets of hexoestrol replaced a single 15 mg. tablet.

6. The implanting of lambs with 20 mg. hexoestrol failed to give a response superior to that obtained with 15 mg. hexoestrol.

7. Each group of lambs receiving hexoestrol treatment showed an increased average carcass weight.
Further observations on the effects of growth checks in pigs of 50 lb. live-weight and over
Authors: Lucas I. A. M. , Livingstone R. M. , McDonald I.
Published: September 2010

Forty-eight individually-fed Large White pigs, initially 10 weeks of age, were used to test the effects of growth checks induced by severe restriction of feed intake. The checks were imposed at 50 lb. or 100 lb. live-weight and lasted for 5 weeks, during which live-weight gains averaged only 1·6 lb. and 4·1 lb. per pig, respectively. The daily feed allowances of the unchecked controls and of other pigs while not on check were according to a fixed scale based on live-weight. All pigs were slaughtered as their individual weights reached 200 lb. and a number of measurements were made on the carcasses.

Excluding the period of the check, efficiency of feed conversion and rate of gain were better for pigs checked at 50 lb. than for the controls. The difference in age at a given weight caused by the check was narrowed by about 6 days at the end of the experiment. Indications of a similar compensation in growth of pigs checked at 100 lb. were mostly explained by the rapid growth of these pigs before 100 lb. and by the sudden increase i n their weight at the end of the check period which was probably due to increased gut fill.

A check at 50 lb. or 100 lb. did not affect either the specific gravity of the carcass, which was taken as an indication of the overall proportion of lean to fat, the area of ‘eye’ muscle, the depth of backfat over the shoulder, the thickness of streak or the Danish ‘slight of lean’ measurement, but the check at 50 lb. increased the thickness of fat at position (1) over the ‘eye’ muscle. Both checks increased the minimum thickness of back fat in females but not in castrates and reduced the average rump fat in castrates but not in females. It was concluded that the checks did not affect carcass composition although they probably caused changes in the distribution of the backfat.
Effect of including an antimycotic (griseofulvin) in the diet of growing pigs
Authors: Barber R. S. , Braude R. , Mitchell K. G.
Published: September 2010

Results of an experiment involving a total of 24 individually-fed pigs, covering the growing period between about 40 and 210 lb. live-weight, indicated that the addition of 20 g./ton griseofulvin to the diet had a slight depressing effect on the rate of growth of the pigs. It had no significant effect on the efficiency of food utilisation, but caused a small reduction in daily food consumption.
Characters of economic importance in Welsh Mountain sheep
Authors: Dalton D. C.
Published: September 2010

1. The influence of seasonal, maternal and genetic variation on body weight and fleece characters of Welsh Mountain sheep is reported.

2. Fertility and rearing ability of ewes improved from first to third lamb crop.

3. Male lambs were on average 0·4 lb. heavier at birth than females. Birth weight increased with number of pregnancies of the dam.

4. Early growth of the lamb between birth and marking (24 days old) used partly as a measure of milk production of the ewe, was greater in males than in females. Lambs born to older ewes made the greatest gains over this period, although the trend was not significant.

5. Weaning weight of the lamb was affected by the dam's weight at tupping, the number of preceeding pregnancies, her milk yield and also by the season in which the lamb was born. Despite these effects weaning weight proved a good guide to the weight (at subsequent matings) at 1½ and 2½ years old.

Heritability by intra-sire parent-offspring regression was 0·51±0·07 (P<0·001) and repeatability was 0·43 (P<0·001).

6. Fleece weight was not affected by season or age of ewe. However, the heaviest lambs at weaning tended to have heaviest fleeces the following year.

Heritability by intra-sire daughter-dam comparison was 0·58±0·11 (P<0·001) and repeatability was 0·46 (P<0·001).

7. Staple length measured on the mid-side of the animal had a repeatability between years of 0·56 (P<0·001) while heritability by daughter-dam regression was 0·38±0·ll (P<0·001).

8. Fourteen Welsh Mountain rams were progeny tested. Nine of the rams were purchased at local sales and 5 were home bred. They were not selected for the traits examined.

No statistically significant differences were obtained between sire progeny groups for weaning weight and fleece weight.
The effects on production efficiency of oleandomycin and oxytetracycline fed at low levels in the diet of heavy pigs
Authors: Vernon J. , Mercer E. A. , Rosen G. D.
Published: September 2010

Results are presented of an investigation involving 328 pigs on 7 farms in East Anglia, on the effect of oxytetracycline (10 g./ton), oleandomycin (2·5 g./ton) and oxytetracycline (10 g./ton) plus oleandomycin (2·5 g./ton), on the live-weight gain, feed consumption and feed conversion efficiency of pigs from weaning to slaughter at approximately 260 lb. live-weight. Effects on number of days from weaning to slaughter and carcass characteristics are also given.

Both antibiotics gave significant improvements in daily live-weight gain (5·4% for OTC and 4·0% for OM) and feed conversion efficiency (3·9% for OTC and 2·3% for OM). There was a significant negative interaction between the antibiotics on live-weight gain from weaning to slaughter.

The average number of days from weaning to slaughter was significantly reduced by both antibiotics (5·8 days for OTC and 5·4 days for OM) and there was a significant interaction between antibiotics.

Feed conversion efficiency for all pigs was significantly better on those farms where antibiotics had not previously been used but the antibiotic treatment effects were the same in both categories of farm studied.
Genetic parameters of British Large White bacon pigs
Authors: Smith C. , King J. W. B. , Gilbert N.
Published: September 2010

Estimates of heritabilities and genetic correlations among 35 measurements and scores of British Large White bacon pigs are reported. The data came from pigs tested at the five National Progeny Testing Stations during the period autumn 1957 to spring 1959, and comprised full records on 1936 pigs from 200 sires. Independent analyses were carried out for each sex, and adjustments were made to the data for differences among stations, six-monthly periods and weight at slaughter.

Genetic parameters were estimated from sire components of variation and covariation obtained by conventional heirarchical analyses of variance and covariance. Estimates of the heritabilities and their standard errors are given in Table 2, and of genetic and phenotypic correlations in Table 3. These estimates, which agree in general with other estimates in the literature,, indicate that a large part of the variation and covariation is of genetic origin and that carcass traits, growth rate and food conversion efficiency are amenable to change by selection. Moreover, no serious antagonisms were found to exist with regard to improvement by selection.

An attempt has been made to summarise the correlation matrix pattern among 24 of the more important traits by using a principal component analysis. The first two principal components account for a disproportionate fraction of the correlation pattern especially of the genetic correlation matrix. Two principal components are given for each trait; the first may be associated with measurements of fat depth.
Fleece characteristics of three strains of Scottish Blackface sheep
Authors: Doney J. M. , Smith W. F.
Published: September 2010

Fleece characteristics of three distinct strains of Scottish Blackface sheep were studied by sampling eighteen ewes of the Lanark, Galloway and Lewis strains on three occasions in a single year. During the period of maximum growth the Lewis strain, which is largely of historical interest, differed significantly from the others in S/P ratio and mean weight, diameter and degree of medullation in fine and coarse fibres. The differences between the other two strains were small and although a considerable range in fleece characteristics was found, most of the whole fleeces would be classed as ‘medium’ wool.

All three strains showed a considerable reduction in follicle output during the winter and spring months when differences amongst them were minimised.
A note on energy intake and nitrogen balance of fattening lambs given all-concrate diets
Authors: Davies P. J.
Published: September 2010

The growth rate and food conversion efficiency of fattening lambs given all-concentrate diets have been reported by Philip Preston and Greenhalgh (1964). The lambs were weaned abruptly at 8 weeks old and fed thereafter ad libitum on cereal and protein supplement. Owen, Davies and Ridgman (1965) have reported the same measures of performance for artificially reared lambs fed from 30 lb. to slaughter at 75 lb. on diets varying indigestibility. A considerable amount of information has been obtained recently on the nitrogen metabolism of young calves fed on all-concentrate diets (see Preston, Whitelaw, MacLeod and Philip, 1965, and Bowers, Preston, McDonald, MacLeod and Philip, 1965) but there is less information of a similar nature for lambs fed on such diets. The following experiment was carried out to assess the intake of energy and utilisation of dietary nitrogen by lambs fed ad libitum on three simple all-concentrate diets during the latter stages of fattening.
The effect of the proportion of roughage in the diet, diethylstilboestrol implantation and space allowance on the performance of Israeli-Friesian intact male calves
Authors: Holzer Z. , Ilan D. , Levy D.
Published: September 2010

The effects of the proportion of hay in the diet (18 or 40%), implantation of diethylstilboestrol and the type of housing on the performance of male calves was examined over the growth period from 250 to 500 kg live weight in a 2×2×2 factorial experiment. The dry-matter consumption per 100 kg of live weight was lower and the live-weight gain and efficiency of conversion of crude metabolizable energy was higher with the diet containing 18% of hay than with that containing 40%. Diethylstilboestrol implantation had only a small effect on performance. Animals that were allowed yard space in addition to pens gained less rapidly, were less efficient in the conversion of energy into live weight, and were somewhat leaner, than those restricted to pens.
Performance and carcass composition of docked and control fat-tailed Kellakui lambs
Authors: O'Donovan P. B. , Ghadaki M. B. , Behesti R. D. , Saleh B. A. , Rollinson D. H. L.
Published: September 2010

Ninety-three Kellakui fat-tailed single lambs were assigned after birth to a 2×2×2 factorial experiment; 46 were uncastrated males and 47 were females. About half the lambs of each sex were docked before they were 1 week old. Half the lambs had unrestricted milk from the ewes until 115 days of age (phase 1) and the other half received all the ewes' milk for the first 30 days and then about one-third of the milk until weaning at 60 days. Creep feed was avail-able to all lambs from about 3 weeks of age, in addition to 200 g of alfalfa dry matter per lamb daily. From 115 days of age, all lambs were fed on a standard fattening ration until slaughtered at weights of 46 to 49 kg for males and 35 to 38 kg for females (phase 2).

Lambs given unrestricted milk were 7·4 kg heavier than restricted lambs at the end of phase 1. Significantly better gains due to docking were observed only for females during phase 2. There was little indication that docking affected feed conversion efficiency. In docked lambs the fat normally deposited in the tail was partially (less than 50%) relocated as subcutaneous plus intermuscular and internal fat. Lean meat percentages of carcasses were similar for docked and control treatments. There is a need to standardize reporting of results from docking experiments to make valid comparisons.