bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of length of journey by road to abattoir, resting and feeding before slaughter on carcass characteristics in bacon weight pigs
Authors: Cuthbertson A. , Pomeroy R. W.
Published: September 2010

Three trials were conducted to investigate the effect of length of journey by road to the abattoir, resting and feeding before slaughter on carcass characteristics of pigs of about 200 lb live weight.

Trial 1 investigated feeding or no feeding on the morning of slaughter, followed by a ½-hr or 8-hr journey by lorry to the abattoir with all pigs ending their journey and being killed at the same time. Ninety-six pigs were divided equally among the four treatments and the trial was repeated with a further 108 pigs. Measurements recorded on the live pigs and their carcasses included the live weight before the imposition of treatments, weight of liver, carcass and matured sides and the composition of a sample joint. Trial 2 studied lairaging overnight with food and water after a ½-hr or 8-hr journey to the abattoir compared with these journey lengths on the morning of slaughter. Eighty pigs were divided equally among the four treatments. Similar measurements to those in trial 1 were recorded. Trial 3 involved 49 pigs applied to each of three treatments, or 7-hr journey on the day of slaughter, with all pigs finishing their journey and being slaughtered at the same time.

In trial 1, pigs which travelled for 8 hr before slaughter had carcasses averaging 0·9% less than those which travelled for ½ hr, regardless of whether or not they were fed. It could not be established where this loss occurred. Liver weights were greater for those pigs which were fed and was greatest for those pigs which were fed and had the ½-hr journey. Streak thickness was found to be decreased by feeding, but was not affected by the length of the journey. No effects of the treatments were found on pH or eye-muscle colour, but the ultimate pH of the pigs fed before the 8-hr journey was lower than for the other treatments. Trial 2 pigs showed no effect of the treatments on carcass weights. Liver weights were similar on all treatments except for the treatment involving 8-hr journey followed by lairage where the liver was about 220 g (16%) heavier. The ultimate pH value was lowest among pigs which travelled 8 hr on the morning of slaughter but was similar for pigs on the other treatments. In trial 3, loss of live weight tended to increase with increasing journey length. Pigs on the 7-hr journey treatment had about 90 g (6%) more liver than those on the shorter journeys. pH1 values increased with length of journey and the longer the journey the thinner tended to be the maximum shoulder fat thickness.

From the differences in the results from the three trials, notably with carcass weight, it may be inferred that the behaviour and handling of pigs during the journey and during loading and unloading, may play an important part in determining the result of the length of the journey, resting and feeding. Further work is considered necessary to study such factors.
Effects of hormones and diets on performance and carcass characteristics of pigs during summer and winter
Authors: Hale O. M. , Johnson J. C.
Published: September 2010

One hundred and forty-four weanling Duroc barrows were individually fed to study effects of season (summer and winter), energy concentration of the diet (high and low), protein concentration (high and low), and orally administered hormones (none, diethylstilboestrol, and mefhyltestosterone) on performance and carcass characteristics of growing-finishing swine.

In summer the rate of gain of pigs was 6% slower and yielded carcasses with 19% smaller loin-eye areas but 3% more lean cuts than in winter.

Pigs fed on high-energy diets gained 13% faster, consumed 8% less feed daily and required 18% less feed per unit of weight gain than pigs fed on low-energy diets. Pigs fed on high-energy diets also had a dressing percentage 2·5 units higher and yielded carcasses 2% shorter, with 15% more backfat, than those fed on low-energy diets.

Pigs fed on low-protein diets had a dressing percentage 1·6% higher and yielded carcasses with about 7% thicker backfat than pigs fed on high-protein diets. Dietary energy and protein concentrations interacted significantly in their effect on rate of gain. Pigs fed on low-energy, low-protein diets gained weight about 7% faster than pigs fed on low-energy, high-protein diets; however, pigs fed on high-energy, high-protein diets gained weight about 3% faster than pigs fed on high-energy, low-protein diets.

The only significant effect of giving each pig about 2 mg of diethylstilboestrol (DES) per day was a 2% increase in weight of lean cuts. An average daily consumption of 20 mg methyltestosterone (MT) per pig decreased rate of gain, daily feed intake, dressing percentage and backfat thickness, but increased carcass length, area of the loin-eye and weight of lean cuts. Hormones and dietary energy levels interacted in their effects on rate of gain and feed efficiency. Pigs fed on low-energy diets with or without hormones gained weight at about the same rate, but high-energy diets increased rate of gain in pigs receiving no hormone or DES by about 17% and 21%, respectively, while having no effect in pigs receiving MT. Pigs fed on low-energy diets with MT required about 7% and 6% less feed per unit of gain than pigs fed on low-energy diets without hormone or with DES, respectively; whereas pigs fed on high-energy diets containing MT required about 10% and 14% more feed per unit of gain than did pigs fed on high-energy diets without hormone or with DES, respectively.
Factors affecting the interval between calving and conception in Hariana cattle
Authors: Dhillon J. S. , Acharya R. M. , Tiwana M. S. , Aggarwal S. C.
Published: September 2010

Eight hundred and ninety-eight records of the interval between calving and conception (service period) of 349 Hariana cows, the progeny of 79 sires, were analysed by fitting constants for the effects of year, month of calving, calving sequence, sex of the calf, weight of the cow at calving and weight of the calf at birth. The average service period was 272·7 days with a coefficient of variability of 50·7%.

The service period was longest after the first calving. Animals calving in the months of February to August had a longer service period than those calving during the months of September to January. Heavier cows tended to have a shorter service period. Sex of the calf, calving sequence and birth weight of the calf did not affect this trait significantly.

Heritability of service period estimated from the paternal half-sib correlation using repeated records was 0·06 ± 0·018 and repeatability was 0·250 ± 0·039. It seems likely therefore that a shortening of the service period may not be possible through direct selection.
A note on the fertility of rams exposed to high temperatures
Authors: Rathore A. K.
Published: September 2010

Fertility of rams was studied following their exposure to heat for 1 or 3 days in a hot room. Eight to 16 days later exposed rams showed significantly lower fertility as judged by lambing rate of ewes compared with unheated control rams. From 25 to 36 days after exposure treated rams were not significantly less fertile than controls. There were no significant differences in fertility between rams exposed 1 day or 3 days to heat.
Comparison of protein concentrations in diets given unchanged to pigs from 18 to 93 kg live weight
Authors: Lucas I. A. M. , Miles K. L.
Published: September 2010

In the national pig progeny test stations one diet is given up to about 55 kg live weight and another, with less protein, is given from then until slaughter. These diets were compared with four ‘single’ diets, similar in digestible-energy content, but containing either 15·6, 17·4, 18·7 or 22·1% crude protein, and each given unchanged from 18 to 93 kg live weight. There were twenty groups of one castrate and one gilt on each treatment.

Pigs given the lowest protein levels had the poorest growth rates and feed conversion efficiency up to 57 kg live weight, but the best from 57 to 93 kg. Hence there were no differences in overall feed efficiency, and overall growth rate was only slightly less with the lowest protein level than with other treatments.

Carcass leanness rose with protein level in the ‘single’ diets over the range 15·6·18·7% crude protein, but a further increase to 22·1% reduced leanness.

Pigs given the progeny test diets had carcasses intermediate in composition to those of pigs on the ‘single’ diets with 17·4% and 18·7% protein.
Beef production from grass and silage with autumn-born calves. 2. The effects on the performance of cattle fed on silage of barley supplementation and of previous grazing intensity
Authors: Wllkinson J. M. , Prescott J. H. D.
Published: September 2010

1. Two experiments are described in which the consequences of variation in grazing intensity were studied during the subsequent period of winter feeding from 12 months of age to slaughter at 18 months. The cattle were loose-housed and fed on silage ad libitum, together with allowances of rolled barley. Individual organic-matter intake was measured periodically, chromic oxide being used to estimate faecal output. The digestibility of the diet was estimated with stall-fed steers.

2. Groups of 12 steers were grazed at different intensities over five-month periods, so that those grazed at the higher intensity were 38 and 16 kg lighter at the start of the 1966 and 1967 winter feeding periods respectively. They did not make significant compensatory growth over the subsequent winter feeding periods, although they had a significantly higher intake of feed organic matter per 100 kg live weight than the control steers.

3. With supplements of 3·63 and 1·81 kg/head per day of barley, live-weight gains were 0·77 and 0·50 kg/head per dayin the first half of the winter, but in the second half, when barley allowances were raised to 4.54 and 2·72 kg/head per day, both groups gained weight at the same rate (0·94 kg/head per day).

4. The higher level of barley feeding reduced silage intake by 0·4 kg OM/kg barley OM at all stages of the winter, and the additional 306 kg of barley was associated with the production of 21 kg more carcass weight at slaughter. This higher yield of carcass was reflected in a higher weight of fat in a three-rib sample joint.
A note on a tremor condition in adolescent pigs
Authors: Gedde-Dahl T. W. , Standal N.
Published: September 2010

A temporary tremor condition in adolescent pigs is described which shows similarities with a tremor condition known to occur in young piglets. Growth and carcass traits were on average superior in affected pigs compared with unaffected litter-mates, paternal half-sibs and genetically unrelated pigs. Females were over-represented among the affected pigs which were born in large litters.
Some effects of alternating high and low levels of feed intake on the performance and composition of the growing pig
Authors: Fowler V. R. , Livingstone R. M.
Published: September 2010

Three experiments were carried out in which the level of feed intake of pigs growing from approximately 30 to 90 kg was alternately raised and lowered, using different amplitudes and time-periods. Within each experiment, the total feed intake and the length of the experimental period were the same for all treatment-groups.

The two amplitudes which were examined were 112%–88% and 125 %–75% of standard scales of feeding. The time-periods between switches to the alternate level were 1, 3, 7 or 14 days. The impact of the fluctuations in feed intake on overall performance and carcass composition was either trivial or small, and in no case exceeded 5% for any one measurement. It is concluded that fluctuations in feed intake occurring in practical situations will have only trivial effects on performance, provided that pigs receive similar amounts of feed in the same overall period of time.
Growth patterns of muscles of Merino sheep from birth to 517 days
Authors: Lohse C. L. , Moss F. P. , Butterfield R. M.
Published: September 2010

Eighty-two Merino sheep from birth to 517 days old were dissected into individual muscles. A system of overlapping growth coefficients was used to classify the growth patterns of 96 muscles and nine muscle groups. The relative size of muscles and groups at birth and one year are expressed as percentages of total half-carcass muscle weight.

Some differences were noted from the previously recorded growth patterns of bovine muscles. The groups of muscles in the proximal part of the pelvic limb and those surrounding the spinal column were relatively faster-growing in sheep than in cattle.

The patterns of the muscle groups are discussed relative to their function and it is shown that the patterns of growth of muscles within some groups are markedly different from the pattern of the whole group. This is most apparent in those groups with complex functions, and it is clear that anatomical grouping of muscles and functional grouping of muscles will be similar only in those regions of the body with relatively simple actions.
Energy and protein supplements for straw-based winter diets for suckler cows
Authors: Ball C. , Broadbent P. J. , Dodsworth T. L.
Published: September 2010

A variety of energy and protein supplements for winter diets based on barley straw were tested in experiments carried out over three years with spring-calving suckler cows. All the supplements resulted in satisfactory calf weaning weights and cow performance but there were indications that a low level (2·3 kg) of barley plus 68 g urea adversely affected the birth weights of calves and their performance from birth to turnout.
A note on the effects of changing the concentration of protein in the diet offered to fattening beef cattle
Authors: Kay M. , Macdearmid A.
Published: September 2010

Two growth trials were carried out with a total of 112 British Friesian steers to examine the effects of offering all-concentrate diets containing different concentrations of crude protein. In Experiment 1 the steers were offered a diet containing either 17·5 % (H), 14·5 % (M) or 11·5 % (L) crude protein in the dry matter from 100 to 250 kg live weight and changed to diet M, L or one containing 9·5% crude protein in the dry matter (VL) between 250 kg and slaughter, so that the protein content of the diet offered to each steer was lowered by between 2 % and 3 % at 250 kg. In Experiment 2 the diets used were H and M between 100 and 250 kg and M and L between 250 kg and slaughter. Some steers in Experiment 2 were offered the same diet (M) throughout the experiment. Steers offered diet L between 100 and 250 kg ate less feed than steers given diet H and grew at a slower rate than steers given either diet H or M. Those steers given diet VL between 250 and 350 kg grew more slowly than those given diet M or L. For most steers a considerable saving in supplementary protein could be achieved by adopting an ML sequence rather than an HM or MM sequence when formulating dietary supplements.
Rearing of dairy cattle 6. The effect of length of grazing rotation on animal and herbage production in a grazing system for calves and heifers
Authors: Leaver J. D.
Published: September 2010

A rigid system of grazing management was examined for 2 years using rotations of fixed length. Rotations of 21 and 35 days were compared at low (3 calves+ 3 heifers/ha) and high (4 calves+ 4 heifers/ha) stocking rates. The calves and heifers grazed the paddocks on a leader/follower basis.

Average growth rates for the 21- and 35-day rotations were respectively 0·75 and 0·78 for calves and 0·78 and 0·83 kg/day for heifers, but these differences were not significant. The 35-day rotation produced 6% more live-weight gain and 4% more herbage dry matter/ha than the 21-day rotation. The high stocking rate produced 14% more live-weight gain but 3% less herbage dry matter/ha than the low stocking rate. The total percentage utilization of herbage dry matter for the whole season was similar for 35- and 21-day rotations, averaging 90%. There were no significant interactions between length of rotation and stocking rate.
Effects of using rations of reduced energy concentration for intensively reared beef cattle from 250 kg live weight to slaughter
Authors: Broadbent P. J. , Ball C. , Dodsworth T. L.
Published: September 2010

1. Two experiments are described in which castrated Ayrshire cattle were reared on a conventional all-concentrate diet to 250 kg live weight. In Experiment 1 the effect of feeding a 1: 1 mixture (by weight) of barley and wet distiller's grains (WDG) from 250 to 408 kg live weight was examined. In Experiment 2 swedes and grass silage were offered in addition to WDG and barley during the growth phase from 250 kg live weight to slaughter. In both experiments a control group was fed an all-concentrate diet.

2. The introduction of WDG to the diet (Experiment 1) caused a significantly lower daily live-weight gain (P < 0·01) and an increase i n time to slaughter (P < 0·01). Carcasses from the control and treated animals were similar in weight, conformation and composition. There were no differences in growth rates in Experiment 2. The treated animals were heavier (P < 0·01) and older at slaughter (P < 0·001) than those in the control group and they produced heavier carcasses (P < 0·05). The carcasses were similar in composition but some differences in conformation occurred. These effects were the consequence of selecting animals for slaughter on the basis of equal finish (i.e. the ratio of muscle plus fat to bone assessed subjectively).

3. The effect of reducing the dietary energy concentration appears t o be smaller with cattle over 250 kg live weight than with younger, lighter cattle. The results, which are discussed in economic terms, suggest that castrated Ayrshire cattle reared on all-concentrate diets should be changed to a diet of lower energy concentration using cheaper feed sources at 250 kg live weight.
Beef production from formic acid-treated and wilted silages
Authors: Hinks C. E. , Edwards I. E. , Henderson A. R.
Published: September 2010

1. Herbage was ensiled, fresh at 17% DM or wilted to 32% DM, with and without the addition of formic acid (19·2 kg/tonne DM). The silages were fed individually ad libitum to 36 fifteen-month-old British Friesian steers of about 280 kg initial live weight (nine animals per treatment).

2. Wilting and the application of formic acid both inhibited fermentation, resulting in silages with higher levels of water-soluble carbohydrates, lower concentrations of volatile nitrogen and lower organic acid contents.

3. There were no significant dry matter × formic acid interactions in dry-matter intake or daily live-weight gain.

4. Treatment with formic acid did not enhance significantly either dry-matter intake or daily live-weight gain. Furthermore, it had little effect on digestibility, nitrogen retention or metabolizable energy (ME) concentration.

5. Wilting before ensiling increased dry-matter intake from 5·0 to 8·3 kg/head per day with consequent marked increases in ME intake, nitrogen retention and live-weight gain. Wilting, however, had little effect on digestibility, ME concentration, or the efficiency with which dietary nitrogen intake was retained.
A note on detection of oestrus in cattle bred by artificial insemination, and the measurement of embryonic mortality
Authors: Wood P. D. P.
Published: September 2010

Insemination and calving dates were obtained for 2618 British Friesian cows served twice by artificial insemination, the first time unsuccessfully, the second time successfully. The intervals between the two inseminations formed a multi-modal set of normal distributions with peaks at 21-day cycles. The standard deviation of the Kth distribution was 3·0y/K days, with about 58·5% of eligible animals submitted at each cycle. Nearly 84% of all intervals conformed to the normal distributions, suggesting that embryonic mortality occurred in about 16% of cases following the first oestrus after insemination.
Changes in live weight and body condition of rams of three breeds throughout the year
Authors: Russel A. J. F. , MacDonald A. J. , Kerr C. D. , Rudd Brenda
Published: September 2010

Measurements of the live weight and body condition of 105 Scottish Blackface, North Country Cheviot and South Country Cheviot male sheep (rams) per year were made at three locations over a period of 2 years.

A distinct cyclical pattern of change in live weight and body condition throughout the year was apparent in all rams. Maximum values recorded in the autumn were followed by rapid and substantial losses throughout the mating period, with recovery of both weight and condition during the spring and summer months. The amplitude of the annual live-weight curve was of the order of 20 kg (22%) and that of body condition was more than 1 unit.

The patterns of annual change in live weight and of inferred change in body composition of rams are compared with those of ewes, and some of the probable effects on production are considered.
Mixed grazing of cattle and sheep versus cattle only in an intensive grassland system
Authors: Dickson I. A. , Frame J. , Arnot D. P.
Published: September 2010

During the period 1974-77 six blocks of a perennial ryegrass/white clover sward were each divided into two for rotational paddock-grazing and silage cutting in alternate years. For each use an annual total of 360 kg nitrogen per ha was applied. Six livestock treatments of cattle only or cattle and sheep were grazed on the blocks. The stocking rates per ha and combinations of cattle (yearling steers) and sheep (ewes nursing twin lambs) respectively were low, 7·5 + 0; medium, 10 + 0, 7·5 + 5, and 5+10; and high, 7·5 + 10 and 5 + 15.

The annual quantities of herbage organic matter accumulated (6·6 to 7·2 t/ha) and consumed (5·6 to 6·7 t/ha) did not differ markedly according to grazing treatment during an individual year, nor was there an effect on organic matter accumulation in subsequent conservation years (11·3 to 12·0 t/ha). Between-year effects were significant. As judged by persistence of sown species there was no evidence of sward deterioration over the 4 years.

Total live-weight gain per ha increased with increasing stocking rate but with a decreasing increment. The ranges were 106 to 1·42 t/ha within treatments, 102 to 1/45 t/ha within years and 0·97 to 1·8t/ha within treatments × years. Individual gains of cattle (0·67 to 0·88 kg/day) and lambs (0·20 to 0·27 kg/day), and the proportion of lambs ready for slaughter (0·53 to 0·97), were lowest at the highest stocking rate. Mixed grazing compared with cattle-only led to improved cattle gains and improved total gains per ha. The benefits of mixed grazing for a species tended to increase as the proportion of that species in the mix decreased.
Effects of plane of nutrition and season of birth on the age and body weight at puberty of British Friesian heifers
Authors: Little W. , Mallinson C. B. , Gibbons Diana N. , Rowlands G. J.
Published: September 2010

1. Four groups of British Friesian heifers born in April (no. = 30), July (no. = 29), October (no. = 30) 1977 and January 1978 (no. =27) were allocated to one of six treatments (planes of nutrition) at a mean age of 91 days. From 91 to 365 days of age heifers on treatments 1 to 5 were given individually, according to body weight, a proprietary pellet to 126 days of age, and thereafter a diet of dried lucerne and barley. Heifers on treatments 1 and 2 were fed at the same rate whereas heifers on treatments 3 to 5 were fed at successively higher rates. Heifers on treatment 6 were fed ad libitum the proprietary pellets to 126 days of age and thereafter a 'barley beef diet. Mean live-weight gains between 91 and 365 days of age for treatments 1 and 2 combined and 3 to 6, respectively, were 0·58, 0·68, 0·75, 0·82 and 1·06 kg/day.

2. Plasma progesterone concentrations were determined twice weekly in each animal. Puberty was assumed to have occurred 2 days before the start of the first period in which the progesterone concentration exceeded 1μg/1 for at least 10 days.

3. There was no significant difference between treatments in mean body weight at puberty (242 kg), but age at puberty (347, 305, 288, 301 and 239 days for treatments 1 and 2 combined and 3 to 6, respectively) was inversely related to rate of live-weight gain between 91 and 365 days of age. However, within each treatment group the fastest growing heifers reached puberty at the same age but at a heavier body weight than the slowest growing heifers.

4. There were significant seasonal effects on age and body weight at puberty. The most rapidly reared animals (treatment 6) born in January and April were, on average, 52 days younger and 54 kg lighter at puberty than those born in July and October, but the effects of season of birth in other treatments were different.

5. There was no significant difference between treatments in the number of conceptions (mean 0·67) achieved at first service by an Aberdeen Angus bull introduced when the heifers were 350 days of age.
Inheritance of teat number and teat inversion in pigs
Authors: Clayton G. A. , Powell J. C. , Hiley P. G.
Published: September 2010

Total teat number in a Large White and a British Landrace population had a modal number of 14. The trait was highly leptokurtic, indicated by the fact that 086 of the population falls within one standard deviation of the mean. There was no sex difference in total teat number, although a small but significant breed difference existed. Heritability of the trait was low, of the order of 0·10 to 0·20 based on the sire component of variance. Larger dam terms suggested a maternal effect.

Severely inverted teats (nipple invisible) were observed in 0·17 of gilts. Mean number of inversions was 0·738 in the entire population but 4·01 in affected gilts. The heritability of the trait was of the order of 0·20 and a maternal component was possibly involved.

Inverted teats are not distributed at random. They occur most frequently in the umbilical and anterior regions and diminish sharply in frequency towards the rear. In this study 0·97 of all affected pigs had one or more inverted teats in the umbilical and anterior regions.
Studies on the shearing of housed pregnant ewes
Authors: Russel A. J. F. , Armstrong R. H. , White I. R.
Published: September 2010

Two experiments were conducted in successive years with, respectively, 112 and 194 mature Scottish Blackface ewes to study the effects of shearing during pregnancy on lamb birth weight and subsequent growth. In each year half the ewes were shorn approx. 10 weeks before lambing. Shorn and unshorn ewes were offered and consumed equal quantities of food.

In both years the shorn ewes lost approx. 2 kg of live weight shortly after shearing (making allowance for the weight of wool removed); thereafter live-weight differences remained relatively constant. Plasma 3-hydroxybutyrate concentrations indicated that the initial live-weight loss was probably attributable to short-term increases in heat production and energy expenditure.

Respiration rates and rectal temperatures of unshorn ewes were always higher than in shorn ewes, but were not elevated to an extent indicative of heat stress.

Shearing had no effect on the birth weights of single or twin lambs, nor was there any effect on lamb growth rate to 14 weeks of age.

It is postulated that the effects of shearing on lamb birth weight reported by others working with sheep fed ad libitum are most likely to be due to the increased voluntary food intakes of shorn ewes.
Food intake, growth and body composition in Australian Merino sheep selected for high and low weaning weight. 1. Food intake, food efficiency and growth
Authors: Thompson J. M. , Parks J. R. , Perry Diana
Published: September 2010

Changes in the pattern of food intake, food conversion efficiency and growth from weaning to maturity, were examined in 35 rams and ewes from flocks of Merino sheep selected for high (weight-plus) and low (weight-minus) weaning weight and from a randomly bred control flock. The sheep were individually fed a pelleted rationad libitumfor at least 72 weeks and up to 90 weeks post weaning. Weekly food intake was described as an increasing exponential function of age with a linearly declining asymptote, about which a regular oscillation occurred, and weekly body-weight gain was described as an increasing exponential function of weekly food intake, about which a regular oscillation also occurred.

The oscillations in weekly food intake had a period of about 52 weeks and appeared to be largely associated with seasonal variations in temperature, with an increased food intake during winter and a decreased food intake during summer. The oscillations in both the food-intake and body-weight functions were of similar phase and period and it was suggested that the body-weight oscillations were due to variation in gut-fill, a result of the seasonal oscillations in food intake.

Selection for weaning weight changed the shape and magnitude of the food-intake curve, with the weight-plus having a greater rate of food intake (i.e. appetite) in the early stages of growth and a greater asymptote than the weight-minus animals. Selection for high and low weaning weight also resulted in an increase and a decrease in mature weight. Both strains had a similar growth efficiency, although when calculated as gross food conversion efficiency the weight-plus were higher than the weight-minus animals at the same body weight, whereas there was no difference between strains at the same age.

The rams had both a higher asymptote and a slower rate of decline in food intake than the ewes. Rams had a higher mature weight than the ewes, although ewes had a slightly greater growth efficiency. However, when calculated as gross food conversion efficiency, ewes tended to be lower than rams, when compared either at the same age, or at the same body weight.

When the food-intake curves were standardized for differences in mature size, strain differences in the magnitude of the food-intake curves were reduced, although differences in the shape were still apparent. Shape differences in the food-intake curves were reflected in the shape of the standardized growth curves, with the weight-plus maturing at a faster rate than the weight-minus animals. There was little difference between the sexes in the initial shape of the food-intake curve, although at later ages ewes had a lower food intake than rams. There was little difference between the sexes in the shape of the standardized growth curves.
Food intake, growth and body composition in Australian Merino sheep selected for high and low weaning weight. 3. Energy balance
Authors: Thompson J. M. , Parks J. R.
Published: September 2010

Using a simplified energy balance equation, changes in energetic efficiency and energy expenditure were examined as a function of stage of maturity in rams and ewes from flocks of Merino sheep selected for high (weight-plus) and low (weight-minus) weaning weight and from a randomly bred control flock.

Specific combustion energy of the body (i.e. MJ/kg of body weight) was an increasing linear function of stage of maturity, which increased at a slightly faster rate in the weight-minus than in the weight-plus animals (15·1 v. 13·1 MJ/kg per unit of maturity), and at a faster rate in ewes than in rams (17·2 v. 11·3 MJ/kg per unit of maturity). At maturity, all strains had a similar mean specific combustion energy (18·3 MJ/kg), whereas the ewes were greater than the rams (20·1 v. 16·6 MJ/kg).

Thermochemical efficiency (TCE, defined as the gain in body energy per unit of metabolizable energy intake) was a quadratic function of stage of maturity. In the early post-weaning period, the weight-plus had a greater TCE than the weight-minus animals and the maximum TCE occurred at an earlier stage of maturity in the weight-plus than in the weight-minus animals (0·40 v. 0·45 maturity). The ewes had a higher TCE than the rams at all stages of maturity, although the differences decreased as the animals matured. The maximum TCE occurred at a later stage of maturity in the ewes than in the rams (0·46 v. 0·38 maturity).

After scaling for differences in mature size there was little difference between the strains in the rate of energy expenditure, with the exception that at the later stages of maturity the weight-minus animals had a slightly greater rate of energy expenditure. After scaling for differences in mature size, the rams had a greater rate of energy expenditure than the ewes from weaning to maturity.
The effects of using the wrong genetic model to predict the merit of crossbred genotypes
Authors: Kinghorn B. P. , Vercoe P. E.
Published: September 2010

This paper evaluates the consequences of using the wrong genetic model when predicting the merit of previously untested crossbred genotypes. Eight models are considered, seven including different biological interpretations of two-locus epistatic interaction, plus one excluding epistatic effects. Published results from 13 genotypes generated from Hereford and Angus parental breeds were analysed, and predictions of a further seven genotypes made using different models. Under a dominance model, the predicted superiority in pregnancy rate (%) of a ¾ Hereford: ¼ Angus composite over a two-breed rotation was +1·2%, yet under all other models this was a negative value ranging from –1·9% to –3·7%. However, few such cases were found in which significant decision errors could conceivably be made. It is concluded that decisions on the choice of crossbred genotypes are generally quite robust to differences in the genetic model of the type studied here
Variability of soya-bean lectin binding sites in the brush border membranes of calf intestinal epithelium
Authors: Hendriks H. G. C. J. M. , Koninkx J. F. J. G. , Draaijer M. , van Dijk J. E. , Raaijmakers J. A. M. , Mouwen J. M. V. M.
Published: September 2010

An enzyme-linked lectin sorbent assay (ELLSA) has been used to determine quantitatively the amount of soya-bean agglutinin (SBA) binding sites in and the sialic acid contents of small intestinal brush border membranes (BBM) of a group of 14 clinically healthy veal calves. Computer analysis of the results indicated 704 (s.e. 27) nmol SBA binding sites per mg of BBM protein with a Kj of 2·63 (s.e. 0·15) × 10-5mol/l; the sialic acid contents were 2·67 (s.e. 0·43) mg/g BBM protein. We could not demonstrate a correlation between the amount of binding sites and the sialic acid contents of the BBM.

Incubation with neuraminidase did not alter the number of SBA binding sites.
Relationships between fat depots and body condition score or tail fatness in the Rasa Aragonesa breed
Authors: Teixeira A. , Delfa R. , Colomer-Rocher F.
Published: September 2010

The relationships between body fat depots and body condition score (BCS) were determined in 52 adult Rasa Aragonesa ewes aged 10 (s.d. 2) years and ranging in BCS from 1·5 to 4·5. BCS of each ewe was assessed by three people, the repeatability within individuals being 90% and between individuals 80%. The ewes were weighed before slaughter. After slaughter the omental, mesenteric, kidney and pelvic fat were separated and weighed. The fat of the left side of the carcass was separated into subcutaneous and intermuscular depots. The relationship between live weight and BCS was semilogarithmic and those between fat depots and BCS were logarithmic. Regression analysis was also used to describe the relationships between the various fat depots and BCS or live weight. Of the variation in total fat weight, proportionately 0·90 was accounted for by variations in BCS, while 0·84 was accounted for by variations in live weight. For individual fat depots proportionately 0·86 to 0·90 of the variation was accounted for by variation in BCS and 0·69 to 0·79 by variation in live weight. BCS was a better predictor than live weight of the weight of both total body fat and the individual fat depots.

A curvilinear regression between BCS and live weight showed that the increases in live weight for a unit change in BCS was 7, 10, 12 and 16 kg for each one point increase in BCS from 1 to 5 respectively.

The tail fat depot (tail fatness score) was assessed in the same ewes by score on a three-point scale. Of the variation in the weight of individual fat depots, proportionately 0·79 to 0·86 was accounted for by variation in tail fatness score. Thus the tail fatness score could be used as an additional method of assessing body condition in the Aragonesa breed.
The digestible and metabolizable energy value of copra meals and their prediction from chemical composition
Authors: Thorne P. J. , Wiseman J. , Cole D. J. A , Machin D. H.
Published: September 2010

Digestible (DE) and metabolizable (ME) energy values for five copra meals and a sample of raw copra, with oil contents ranging from 4 to 662 g/kg, were determined with both a high and a low energy basal diet in a metabolism experiment using 16 female pigs. Determined DE values ranged from 12·68 to 29·92 MJ/kg dry matter (DM) and values for ME from 11·95 to 29·08 MJ/kg DM which was a reflexion of their residual oil contents. Regression equations for the six samples were derived with DE and ME as dependent variables and chemical measurements and gross energy as independent variables. The best equation based on a single chemical parameter (ether extract (EE)) was:

Improvements associated with including more than one independent variable in the regression analysis were marginal. The most accurate equation (in terms of minimized residual s.d.) based on EE and crude fibre (CF) was:
Estimates of genetic and phenotypic parameters of litter traits from closed lines of pigs
Authors: Gu Y. , Haley C. S. , Thompson R.
Published: September 2010

Phenotypic and genetic analyses of the litter traits total number born, number born alive and total birth weight were conducted on data from two lines of pigs, line A, a synthetic largely of Landrace origin, and line B, derived from the Large White breed. The data were collected from closed herds of the Cotswold Pig Development Company Limited and comprised 1018 litters in line A and 863 litters in line B. Estimates of heritability and repeatability were low for all traits and consistent with other estimates in the literature, for number born alive being respectively, 0·07 (s.e. 0·04) and 0·15 (s.e. 0·04) in line A and 0·12 (s.e. 0·04) and 0·14 (s.e. 0·04) in line B. There was no evidence of an effect of the size of litter into which a female was born on her subsequent reproductive performance.
Hexoestrol implantation of Blackface wether lambs
Authors: Armstrong R. H. , Cameron A. E.
Published: September 2010

1. Sixty-four Blackface wether lambs, weaned some 8 days previously from the hill were divided into two similar groups. One group of lambs was implanted with 15 mg. hexoestrol.

2. The treated lambs had gained an average of 2·32 lb., and 3·88 lb. live-weight more than the control group, after 4 and 7 weeks respectively.

3. The mean carcass weight of 23 hexoestrol-implanted lambs was 1·5 lb. greater than that of the same number of untreated lambs.

4. Carcass grading provided no evidence of a deterioration in quality as the result of hexoestrol implantation.

5. Light lambs responded at least as well as heavy lambs to the hormone.
Measurements of back fat thickness on live pigs by ultrasonics
Authors: East E. , Taylor J. , Miller I. T. , Widdowson R. W.
Published: September 2010

The back fat thickness of 77 live pigs has been measured with an ultrasonic instrument. The method is simple to use and the ultrasonic waves do not harm the pigs. For measurement of a pig on one day, 95% of the mean ultrasonic readings are within ±13·2% of the mean measurements on the carcass.

Evidence for variations between the breeds examined or between sexes is doubtful. By taking repeated measurements on a large number of days, the accuracy of the mean readings for a pig would approach the limit inherent in the method. This limit is determined by small differences between pigs and is estimated to be within ±4·2% for 95% of pigs.
Effects of feeding formalin-treated skim milk to calves
Authors: Preston T. R. , Rattray E. , White F.
Published: September 2010

1. 2-week-old calves previously fed whole milk were changed abruptly o t skim milk which had been treated with formalin to give a final concentration of 0·1% of the preservative.

2. Difficulty was experienced in accustoming the calves to drink such formalin-treated milk and scouring invariably occurred within two days of the changeover.

3. Post-mortem and histological examination of calves fed formalin-treated skim milk showed severe damage to the alimentary tract compatible with clinical symptoms.

4. None of the above findings was apparent in control calves fed untreated skim milk.
The effect of plane of nutrition during rearing on growth, production, reproduction and health of dairy cattle. II. Growth to maturity
Authors: Crichton J. A. , Aitken J. N. , Boyne A. W.
Published: September 2010

1. The four systems of rearing dairy heifer calves, described in Part 1 of this series are now studied for their effect on absolute and relative growth rates to maturity.

2. Data on live-weights and measurements and the percentages of mature size attained by these at 44, 80, 104, 132, 182, 260 and 312 weeks of age are tabulated.

3. In all groups the measurement to reach maturity earliest was circumference of metacarpus followed in order by length of back, height at withers and width of hooks.

4. By 6 years of age all groups had attained approximately the same body size. Maturity in the LL group in terms of four skeletal measurements was delayed by only 9 months, and in the case of HL and LH animals by 5 and 4 months respectively.

5. All groups showed the same general pattern of relative growth but the effect of restricted feeding was to increase at the younger ages the difference i n percentage of mature size between early and late maturing measurements. After 44 weeks of age the rate of growth was most rapid in those measurements which were furthest from maturity then.

6. The rate of tissue deposition was markedly increased in high plane animals during early pregnancy compared with low plane. Evidence is presented to show that much of this was lost during lactation.

7. At first oestrus, animals in all four treatment groups had reached the same percentage of mature size for each body dimension (except for length of back in the LL group).

8. From data on 5 animals it is shown that although growth in height at withers and length of back ceased by 6 years of age there was slow but continuous growth in live-weight, middle and heart girths and width of hooks to 9 years of age.
The feed intake of grazing cattle. I. Feed intake of dairy cows on strip and free grazing
Authors: Holmes W. , Osman H. El Sayed
Published: September 2010

1. Eight Ayrshire milk cows were grazed for four 3-week periods from July to October 1957 in a balanced sequence on two strip-grazed and two free-grazed paddocks, each of two acres. Feed intake and digestibility were estimated by the chromic-oxide faecal-nitrogen method.

2. There was no significant difference in average feed digestibility between the treatments. Free grazing cows ate 30·4 lb. dry matter per day and strip grazing cows 28·9 lb. The difference was just significant (p<0·05). There was no significant difference in milk yield, live-weight or live-weight gain per cow.

3. Total feed output per acre was 11% greater on strip grazing when measured by utilised starch equivalent but only 1 % greater when measured by estimated feed consumption. The data suggest that strip-grazed cattle needed less energy for grazing.

4. The results are discussed with reference to their accuracy, their implications on grazing management and their correspondence with estimates of food requirements based on indoor feeding standards.
Progeny testing dairy bulls at different management levels
Authors: Robertson Alan , O'Connor L. K. , Edwards J.
Published: September 2010

1. Records used to compile the Contemporary Comparisons of 57 Friesian, 8 English Ayrshire and 11 Scottish Ayrshire A.I. bulls, each with at least 100 ‘effective daughters’ were analysed.

2. For each bull, the herd-years were divided into three equal groups on the basis of the average heifer yield of both daughters and contemporaries (high-, medium-, and low-producing herd-years) and three independent Contemporary Comparisons were calculated for each bull, one at each of the three yield levels.

3. In the data from England and Wales, the mean Contemporary Comparison declined with increasing mean level of production. This decline was such as to imply that some 20% of the differences in production between herds were genetic in origin. A possible explanation lies in the gradual change from Dairy Shorthorn to Friesian and Ayrshire which has taken place in England and Wales, but not in Scotland, during the last 15 years.

4. The variance within progeny groups within herd-years increased from the low level to the high but the coefficient of variation decreased slightly. The variance between sires also increased with the mean level of production but almost exactly in parallel with that within sires so that the heritability and consequently the accuracy of the progeny test for milk yield was effectively the same at all production levels.

5. The correlation between the true breeding values of the bulls at the different levels was very close to one.

6. From these results it is concluded that there is no need to provide special strains within breeds to suit particular management levels or to concentrate progeny testing in the higher-producing herds and that daughter records from all herds, irrespective of level of production, can be used with equal confidence.
Rearing lambs on a synthetic diet
Authors: Cunningham J. M. M. , Edwards R. A. , Simpson Margaret E.
Published: September 2010

Twenty-two triplet or small twin lambs were reared in two ways. One group received cow's milk and the other a synthetic milk designed to approximate in composition to ewe's milk.

The group fed synthetic milk made significantly better live-weight gains to weaning. This difference was not maintained after weaning. Possible reasons for this are discussed.
Studies of transferrins in serum and milk of Swedish cattle
Authors: Gahne Bo
Published: September 2010

The transferrins in Swedish cattle were studied with the starch gel method. A continuous tris buffer system was used. With sera from young calves each transferrin allele appeared to determine four fractions. Among some animals from Norway two seemed to have a transferrin type not earlier described for the European cattle breeds. The frequencies of the transferrin alleles found in a bull sample from the Swedish Red-and-White breed were TfA= 0·53, TfD= 0·18 and TfE= 0·29. Family data were in good agreement with the theory of inheritance. The transferrin types were used in parentage testing and a formula is given for the possibility of making exclusions. The value of the transferrin types in diagnosis of zygosity in cattle twins is shown. The transferrins seem to occur in bovine milk also.