bluuebunny/crossref_metadata_2025 huggingface dataset:
A growth and economic comparison of two crosses of pigs when fed ad libitum and to a scale and slaughtered at two weights
Authors: Frape D. L. , Wilkinson J. , Chubb L. G. , Wolf K. L.
Published: September 2010

Weaner Hampshire × Landrace × Large White (Hampshire cross) and Landrace × Landrace × Large White (Landrace cross) pigs were given combinations of three diets differing in crude protein content (high: H, low: Land very low: vl). Hampshire cross pigs at 90 kg, both under ad libitum and restricted feeding had greater rates of gain and eye muscle measurements and shorter carcasses than Landrace cross pigs, but were fatter after ad libitum feeding and more efficient food converters after restricted feeding. The HLL treatment led to improved gain and food conversion compared to the LLH or LLL treatment, whereas the LLH treatment led to larger eye muscle measurements. The LvlH treatment led to greater efficiency and eye-muscle area than treatment Lvlvl at 114 kg. An economic analysis was carried out to assess the relative profitability of slaughtering at a range of live weights. Curves were fitted to the data on food intake and live weight. Values were assumed for major costs, and a seven-day interval was allowed between batches of pigs. The calculations indicated that the H diet led to a slight increase in monetary return per pig per day when it was given in the post-weaning period to pigs fed to a scale. Although the Hampshire cross pigs showed a response to the H diet in the finishing period when slaughtered either at 90 or 114 kg, their calculated return was not increased. Ad libitum feeding led to a greater return for heavy but not, on average, for bacon pigs. Maximum return occurred at slaughter between 70 and 115 kg live weight and was only margin-ally greater for restricted baconers at 90 kg than for ad libitum heavy pigs at 110–115 kg. However, return as a percentage of working plus fixed capital was greater for baconers, but the ratio rose throughout the range of hypothetical slaughter weights in both groups. In-clusion of the cost of borrowing money had a negligible effect on the slaughter weight for maximum return with pigs managed in batches.
A note on the effect of bulk density and digestibility on the voluntary intake of concentrate diets by sheep of two ages
Authors: Andrews R. P. , Ørskov E. R.
Published: September 2010

Three pelleted diets based on rolled barley, whole oats and ground oats respectively were offered ad libitum to mature wethers and growing lambs. With wethers, intakes on the whole oat diet were significantly greater than on the barley diet but digestible dry-matter intakes were not significantly different. On average, growing lambs ate significantly greater quantities of the ground oat diet and whereas digestible dry-matter intakes on the ground oat and barley diets were not significantly different, both were higher than on the whole oat diet. Examined at successive live weights, intakes on the whole oat diet were, at 15 kg, initially lower than on the barley diet but were ultimately higher at 60 kg, when there were no significant treatment differences in digestible drymatter intakes.
Errata
Authors: Bowman J. C. , Hendy C. R. C.
Published: September 2010

Revised Summery

Animal Production: Volume 12, part 1, pp. 55–62: A number of arithmetical errors have been found in the paper entitled: The incidence, Repeatability and effect on dam performance of twinning in british friesian cattle

An estimate of the frequency of twin calvings was obtained from the analysis of over 38 000 calvings of Friesian cows in M.M.B, milkrecorded herds. The incidence of twinning increased from 0·54% in the first parity to 3·37 % in the fifth parity. A significant excess of cows above expected produced either more than one set of twins or no twins at all. Repeatability ranged from 0·028 for cows with three calvings to 0·063 for cows with five calvings.

Data on lactation yield and duration, butterfat percentage and calving interval showed some significant effects of twinning. Consistent trends were noted showing that dams which calve twins have longer subsequent lactations, higher whole lactation yields and lower fat percentages than contemporary dams with single calves. The possible causes for these trends are discussed and are considered to be the lower breeding efficiency and longer calving intervals of dams of twins.
Beef production from additive-treated silages
Authors: Hinks C. E. , Henderson A. R.
Published: September 2010

1. Wilted (32% dry matter) Italian ryegrass was conserved: (A) untreated; (B) with 16·3 g/kg dry matter (4·6 1/t of fresh material) of an 85% w/w formic acid additive; (C) 12·1 g/kg dry matter (2·3 1/t fresh material) each of 85% formic acid additive and formalin (40% w/v formaldehyde); (D) 5·8 g/kg dry matter (1·3 1/t fresh material) each of 85% formic acid additive, formalin and a 96% w/v solution of propionic acid. The silages were individually fed ad libitum to 40 15-mo-old British Friesian steers of about 350 kg initial live weight.

2. Treatment with additives inhibited fermentation, resulting in silages with higher levels of water soluble carbohydrates and lower levels of organic acids than untreated material. Lower levels of ammonia N and higher levels of true protein indicated that some protein protection resulted from the formaldehyde treatment.

3. Formic acid alone (B) had little effect on digestibility but significantly (P<0·05) enhanced dry-matter intake, live-weight gain and nitrogen retention relative to the control (A)

4. Whereas the application of formaldehyde (Treatments C and D reduced the digestability in vivo of nitrogen, significant increases in nitrogen retention were recorde relative to the control (A). Dry matter intake was not affected significantly by treatment with formaldehyde, but at the higher level of application (Treatment C) daily gain was significantly reduced compared with the control (A). These effects are discussed in relation to possible changes in VFA patterns within the rumen and to the levels of formaldehyde used.
Feeding value of wilted silages made using formic acid, formaldehyde and propionic acid
Authors: Donaldson Elizabeth , Edwards R. A.
Published: September 2010

The nutritive value of four silages was compared using eight rumenfistulated wethers. Wilted ryegrass was ensiled without additive (A); with formic acid (13·9 kg/t dry matter) (B); with formic acid (10·3 kg/t dry matter) plus formalin (formaldehyde at 4·8 kg/t dry matter) (C); with formic acid (4·9 kg/t dry matter) plus formalin (formaldehyde at 2·3 kg/t dry matter) plus propionic acid (5·6 kg/t dry matter) (D).

Dry-matter intakes were 13·8, 15·1, 14·3 and 14·3 g/kg live weight for A, B, C and D respectively. Digestibilities of organic matter and dry matter were not affected by the additives. Digestibility of nitrogen and peak ruminal ammonia concentration were significantly (P<0·05) reduced by the addition of formaldehyde.

The effect on rumen fermentation characteristics, of chemically restricting in-silo fermentation, is illustrated. Differences in the rumen volatile fatty acids and in the efficiency of utilization of the energy for growth, fattening and lactation are discussed.
Genetic and environmental factors influencing calf performance in pedigree beef cattle in Britain. 1. The influence of environmental effects on birth, 200-day and 400-day weights
Authors: Pabst W. , Kilkenny J. B. , Langholz H. J.
Published: September 2010

Data collected on the Meat and Livestock Commission's pedigree recording scheme have been analysed by least-squares procedures to measure the effect of environmental factors on calf performance. In total 5524 birth weights, 16 484 200-day weights and 6248 400-day weights were available for 765 herds and seven breeds. The model adopted included terms representing type of cattle within breed, sex of calf, age of dam, year and month of birth, pre-weaning management, herd average level of performance and herd size as fixed effects with sires as random effects. The model accounted for between 19 and 36% of the variation in birth weights and for 36 to 49% and 39 to 69% of variation in 200- and 400-day weights respectively, depending upon breed. For birth weights and 200-day weights age of dam was a significant effect in all breeds. Sex of calf was the main source of variation at all ages, its relative importance increasing with age. Calves from 2-yr-old dams had 200-day weights 5 to 11% lower and calves out of 3-yr-old dams 2 to 9% lower than calves from 5- to 8-yr-old dams. Month of birth was a significant source of variation in most breeds. Pre-weaning management system was confounded with sex and breed. Correction factors for use in the MLC recording scheme were derived from the data.
The length of gestation period of Ayrshire cows when mated with bulls of other breeds
Authors: Laird R. , Hunter E. A.
Published: September 2010

Least squares analyses were undertaken on 1519 gestation lengths of cows mated to Beef Shorthorn, Hereford, Charolais, German Simmental or British Friesian bulls. Gestation length was influenced largely by breed of sireand byindividual sires within breeds. Approximately 100 calvings are required to give a mean value with a standard error of 0·50 day. Heritability of gestation length was estimated to be 0·24±0·05. It is recommended that Artificial Insemination organizations survey and publish the mean gestation lengths of their bulls and that dairy farmers modify, where necessary, pre-partum feeding in the light of this information.
The effect of energy intake and mating weight on growth, carcass yield and litter size of female pigs
Authors: Hovell F. D. DeB. , MacPherson R. M. , Crofts R. M. J. , Pennie K.
Published: September 2010

1. In a comparative slaughter experiment, 12 female pigs (six at 80 kg and six at 100 kg) were allocated at first oestrus to each of five treatments: Treatment 1, initial slaughter, or Treatments 2, 3 and 4, mated and given 19·5, 25·8 or 32·1 MJ ME/day for the last 100 days of pregnancy, or Treatment 5, not mated (virgin) and given 25·8 MJ ME/day over a similar period. Pigs on Treatments 2, 3, 4 and 5 were given the same amount of protein and were killed about 123 days after first oestrus. Piglets were removed at birth.

2. There was no evidence of any special effect of pregnancy in the stimulation of permanent maternal growth. The average live weight, ingesta-free body and carcass gains of the pair-fed, mated and virgin gilts (±SE of difference) were, respectively, 32·3 and 36·9 + 2·8, 27·5 and 27·6 ± 3·4, and 26·0 and 26·7 + 2·1 kg. There were no statistically significant differences between these two treatments in carcass composition, specific gravity or backfat thickness. The mated pigs had lighter livers (P < 0·01) and heavier reproductive tracts (P < 0·05), and lost about 9 kg within a week of parturition.

3. Increasing energy intake increased piglet birth weights (P<005) but had no effect on the number of piglets born. The pigs that were initially heavier (100 kg v. 80 kg) had 1·5 more piglets, though this was not statistically significant (P<0·1).

4. Although there was no special effect of pregnancy on permanent maternal growth, the conversion of food by the once-mated pig was very efficient if an allowance was made for the food cost of producing the piglets.
A comparison of the voluntary intake and digestibility by beef cows of diets based on oat straw and supplemented with different forms of non-protein nitrogen
Authors: Fishwick G. , Parkins J. J. , Hemingway R. G. , Ritchie N. S.
Published: September 2010

Pregnant beef cows were given 2 kg barley per day and oat strawad libitum. The digestibility of the organic matter of the diet was approximately 53% when urea included in the barley was given in one or four feeds per day. Supplementation of the barley with di-ureido isobutane improved the organic matter digestibility to 56·7%. When a solution containing urea, phosphorus, calcium and sodium was included in the straw the digestibility of the diet was 59·0%. These improved digestibilities were not associated with any differences in the concentrations of ammonia in the rumen liquor or blood of the cows.
A note on the individuality of the intake of drinking water by dairy cows
Authors: Little W. , Shaw S. R.
Published: September 2010

The individual water intakes of 16 (four groups of four) lactating dairy cows, measured on 7 consecutive days, were significantly correlated with dry-matter (DM) intakes (range 4·6 to 14·4 kg/day) and milk yields (range 13·7 to 30·0 kg/day). There was no significant correlation with DM content of the feed (range 833 to 898 g/kg), body weight (range 400 to 620 kg) or mean air temperature (range 7·0 to 20·0°C). Applying a multiple regression analysis to the data, the following relationship was obtained: water intake (kg/day) = 2·15 (± 0·415) × DM intake (kg/day)+0·73 (± 0·197) × milk yield (kg/day) + 12·3 (+ 5·57). After adjusting the data for variations in DM intake and milk yield there was no significant difference between the mean daily water intakes of individual cows. There was, however, a significant day-to-day variation in the mean water intakes of the groups of four cows (P<001) which was not explained by variations in DM intake, milk yield or mean daily temperature.
Comparative performance of Holstein-Friesian, Dutch-Friesian and Friesian × Africander heifers in the coastal belt of Mozambique
Authors: Alberro M.
Published: September 2010

The performance of groups of Holstein-Friesian, Dutch-Friesian and Friesian × Africander heifers in the coastal belt of Mozambique was compared over a 3-year period. The three groups of heifers were kept together under a reasonable level of management and feeding, and measurements were made of age at first calving, milk yield, days i n production, milkability, udder wearability, mastitis incidence, calving difficulties, reproductive efficiency, disease incidence, parasitic resistance and mortality.

The highest milk production was obtained with the Holstein-Friesians followed by the Dutch-Friesians. Last came the Friesian × Africander which also showed older age at first calving, poorer milkability, fewer days in production and more udder wear. No significant differences were found in calving difficulties, disease incidence, parasitic resistance, mastitis incidence and mortality. The fertility level was relatively low in all groups.

The results corroborate reports made by several workers that acclimatized European breeds can produce milk efficiently in the not-too-harsh areas of the tropics and sub-tropics if they are properly managed and fed. The main problem seems to be the relatively low fertility rates that are common in these areas regardless of breed.
Potentiation of porcine lipid mobilizing factor by porcine serum and its relationship with growth rate and leanness
Authors: Eckersall P. D. , Carr W. R.
Published: September 2010

The lipolytic activity of porcine lipid mobilizing factor, a pituitary peptide, was potentiated by porcine serum when measured in a rabbit fat-cell suspension. The potentiation caused by sera from 54 individual pigs which had been bred using backfat thickness and growth rate as selection criteria was examined. No significant correlation was found between the potentiation and either of these parameters.
A note on the use of chromium sesquioxide as a marker in nutritional experiments with dairy cows
Authors: Chamberlain D. G. , Thomas P. C.
Published: September 2010

The faecal recovery of chromium sesquioxide (Cr203) was examined in four experiments with non-lactating Ayrshire cows. In the first experiment Cr203-paper was given intraruminally twice daily to cows receiving a diet of hay. The mean recovery of the marker was 0·829 (s.d., (Mil, no. = 12). In the second experiment the marker was given as Cr203 powder to cows receiving a diet of hay and ground barley. The powder was mixed with the barley part of the diet and given in 24 hourly meals per day. The mean recovery of the marker was 0·944 (s.d., 0·079, no. = 8). In the third experiment cows receiving a hay and barley diet were given Cr203 powder suspended in ground-nut oil administered twice daily through a cannula in the duodenum. The recovery of the marker was 0·980 (s.d., 0·027, no. = 3).

In the fourth experiment ground straw impregnated with Cr203 was used as a marker in cows receiving a hay and barley diet. The marker was mixed with the barley and given in eight meals per day. The faecal recovery of Cr2()3 was 0-941 (s.d., 0·022, no. = 7). It is concluded that when Cr203 is used as an indigestible marker in studies with dairy cows its recovery in faeces may be variable and low due to retention of the marker in the stomach. In digestion studies with cows there are considerable advantages in favour of the use of Cr2()3-impregnated straw rather than Cr203 powder or Cr203-paper.
A note on the use of the chicken to predict protein digestibility in the small intestine of sheep
Authors: Henning P. H. , Meyer J. H. F. , Prinsloo J. J.
Published: September 2010

The true digestibility of protein from diets containing one of the protein-rich foodstuffs, sunflower oil cake, cottonseed oil cake, maize gluten meal and fish meal, was determined in chickens and in the small intestine of sheep. With the exception of maize gluten meal, a close correlation was found between digestibility in the two species (r = +0·98; P < 0·05) and in the sheep small intestine between the true digestibility of utilizable nitrogen and acid-detergent insoluble nitrogen content of the diet (r = -0·96; P < 0·05).
Copper deficiency: a study of prophylaxis and the interaction with cobalt therapy in lambs on improved hill pastures
Authors: Whitelaw A. , Russel A. J. F. , Armstrong R. H. , Evans C. C. , Fawcett A. R. , White I. R.
Published: September 2010

An experiment was conducted with 84 suckling Scottish Blackface twin lambs on an improved hill pasture with a history of cobalt deficiency and molybdenum/sulphur-induced copper deficiency. The dams of 13 pairs of twins were treated with 90 mg copper at parturition (Cue) and one member of each pair was given a cobalt bullet (Co + ). One member of each of a further 29 pairs was treated periodically with 5 to 15mg copper to maintain plasma copper concentrations >0·6mg/l (Cu+) while their siblings received no supplementary copper (Cu). Fourteen of these pairs also received a cobalt bullet (Co + ). Lambs not treated with cobalt are designated Co−.

The Cue treatment increased milk copper concentrations, but only for a short time, and resulted in transitory increases in lamb plasma copper concentrations and rate of live-weight gain. At the end of the grazing phase, at approximately 20 weeks of age, Cu+ lambs had gained 0-28 kg more weight than Cue lambs and 158 kg more than Cue lambs, and had higher liver copper concentrations. Cu+ and Cue lambs had heavier and fatter empty bodies and carcasses than Cu− lambs. The cobalt treatment produced no effects at this stage.

Fifty-four of the lambs were housed and given dried grass pellets ad libitum. After 83 days liver copper concentrations were higher in Co− than Co+ lambs, and in Cu+ than in Cu− and Cue lambs. The copper treatments had no effect on rate or efficiency of live-weight gain, but Co− lambs gained weight more quickly and more efficiently than Co+ lambs.
The effect of age at puberty on growth and carcass quality at market weight in the gilt
Authors: Price M. A. , Aherne F. X. , Elliot J. I. , Lodge G. A.
Published: September 2010

Eighty-nine crossbred gilts were used in an experiment to assess the effects of age at puberty on growth and their carcass characteristics at market weight. From 100 days of age each gilt was exposed daily to a boar and observed for standing heat. The gilts were slaughtered in a commercial abattoir as they reached market weight (approximately 109 kg live weight). Thirty-two gilts (36%) reached puberty before slaughter. These 32 earlier-maturing gilts grew more slowly than the other 57 (P<0·001) yet, paradoxically, within the group of 32 which had reached puberty, there was a significant negative correlation between age at puberty and average daily gain (r=−0·565; P<0·001). Of the 32, the date at first oestrus was known in 30 cases. Among these 30, 10 had ovulated more than once (early-maturing) and 20 had ovulated once (intermediate maturing). Consistent with the paradox there was a significant negative correlation between age at puberty and rate of gain within each group but the regression line for the early-maturing gilts had a significantly lower intercept, on the gain axis, than that for the intermediate group (P<0·01). There were no significant differences between sexual maturity groups for any of the large number of physical and chemical carcass characteristics studied.
Genetic control of equilibrium maintenance efficiency in cattle
Authors: Taylor C. S. , Turner H. G. , Young G. B.
Published: September 2010

Twenty-two unmated female Ayrshire twin cattle, that had initially been maintained for prolonged periods on one of six constant feeding levels until an equilibrium weight was attained, were subsequently moved up to higher constant feeding levels including ad libitum. In all, results were obtained for 44 equilibrium periods mostly of 96 weeks duration.

For controlled feeding levels, the log-log,. regression of equilibrium body weight on food intake, within animals, was 0·999 (s.e. 0·045). For all results, including mature equilibria, the within-animal regression was 1–014. There was thus no systematic change in an individual's equilibrium maintenance requirement per kg body weight in the range from 25%, to 100%, mature. Efficiency of food utilization for equilibrium maintenance was found to be independent of age also, except for a small increase at advanced ages beyond 8 to 9 years.

There were significant differences between animals in equilibrium maintenance efficiency, the genetic coefficient of variation being 6·4%. The most striking result, however, was a within-animal repeatability of 0·7, which meant that almost the same efficiency was re-attained when, after a prolonged period of many years on one constant feeding level, the same animal was allowed to re-establish a new equilibrium on a higher level.

Following prolonged periods of food restriction, the animals showed remarkable capacity to recover in body weight even at very advanced ages, but nevertheless substantial stunting of mature weight did occur.
Milk production in East African zebu cattle
Authors: Galukande E. B. , Mahadevan P. , Black J. G.
Published: September 2010

An analysis has been made of milk production data from indigenous East African zebu cattle at the Baraton, Maseno and Sangalo Livestock Improvement Centres in Kenya, covering a period of twenty-five to thirty years.

The relationships between milk production and length of lactation, dry period, calving interval, month of calving and age were examined. Lactation length accounted for from 53% to 66% of the total variance in milk yield. Variations in length of dry period caused significant differences in milk yield between, but not within cows. Increasing length of previous calving interval improved current lactation milk yield but month of calving had no significant effect. Yield increased from first to second lactation by 8% after which it remained relatively constant up to the fifth lactation. Age at first calving was positively correlated with first lactation milk yield.

Intra-herd repeatabilities were 0·55 for milk yield, 0·38 for lactation length, 0·17 for calving interval and 0·12 for dry period. The highest estimates of heritability were those obtained for lactation yield and length (0·5); the lowest, for calving interval, was close to zero. All heritability estimates had high standard errors. The probable genetic improvement in milk production achieved by the selection practised in the herds was estimated as ranging from zero to 0·15% of the average yield per year.
A genetic study of the Sahiwal grading-up scheme in Kenya
Authors: Mahadevan P. , Galukande E. B. , Black J. G.
Published: September 2010

A genetic study of the grading-up of the East African zebu to the Indian Sahiwal has been undertaken on records, covering about 25 years, from three Livestock Improvement Centres in Kenya. It appears from this study that the indigenous East African zebu cow has only about half the genetic potential of the Indian Sahiwal for milk production, and the scheme of gradingup has resulted in substantial and worthwhile increases in milk production.
Breed structure and genetic analysis of Border Leicester sheep
Authors: Young G. B. , Purser A. F.
Published: September 2010

Since the year 1900 the number of Border Leicesters has been fairly stable, between 3,000 and 5,000 females being registered each year. The number of flocks, however, has shown a fairly steady increase from 200 to over 600. There has been a decline in the number of ewes registered per flock from 16 to about 6 to 8. The important flocks would seem to number 15 to 20; only a few flocks persist for any appreciable length of time. Generation intervals are short, being only about 2 years on the sire side and 3½ years on the female side.

As with other breeds, relatively few rams have an importance out of proportion to their numbers—14 rams and 2 ewes with direct coefficients of relationship greater than 5% were found. Inbreeding per generation was only 0·32%, and there was no evidence of strain effects.
Evaluation of piglet mortality in 28 two-breed crosses among eight breeds of pig
Authors: Fahmy M. H. , Holtmann W. B. , MacIntyre T. M. , Moxley J. E.
Published: September 2010

Records of piglet mortality were taken on 775 first and 657 second litters farrowed at four locations and representing 28 combinations of two-breed crosses involving eight breeds. All the sows were mated to Poland China boars. Overall mortality was 18% of which 4·2% occurred at birth, 13·2% between birth and 21 days and 1·2% from 21 to 42 days. Landrace x Yorkshire dams had the lowest mortality rate (10·4%) followed by Duroc x Lacombe (12·3%) whereas the highest rate was found in the Hampshire x Lacombe sows (21·6%). Piglets with Tamworth and Yorkshire ancestry had the lowest mortality (16·2 and 16·7%) while those with Berkshire ancestry had the highest (20·0%). Mortality rate was slightly (2%) higher in first than in second parity litters, and highest in summer and similar in the three other seasons. Mortality rate was highest in very small and very large litters and among the lightest and the heaviest piglets. The results showed a linear relationship between mortality rate and homogeneity of piglet weights at birth within litter, mortality rising with the increase in intra-litter variation. The effect of sires on piglet mortality was significant in one, and non-significant in the three other locations.
A twice-yearly lambing system, using Finnish Landrace×Dorset Horn ewes
Authors: Duncan J. G. S. , Black W. J. M.
Published: September 2010

Between July 1971 and June 1973 a flock of between 60 and 100 Finn-Dorset ewes were mated at 6-monthly intervals in July and January each year following oestrus synchronization. The conception rates at each mating were:

July 1971—51 from 67 mated (76%) using hand-mating with a follow-up of paddock mating (1 ram: 9 ewes);

January 1972—6 from 63 (10%) using artificial insemination only; July 1972—98 from 102 (97%) using paddock mating (1 ram: 10 ewes);

January 1973—28 from 80 (35%) using pen mating (1 ram: 10 ewes).

Satisfactory breeding performance was achieved at the July matings in both years, resulting in production of lambs for the early spring market. The very poor results of the January 1972 mating were associated with the problems of artificial insemination in the recently lambed ewe. The conception rate achieved at the January 1973 mating provided a clearer indication of the difficulty of achieving satisfactory remating within 40 days post partum, which is necessary to achieve a true 6-monthly lambing pattern.

The early initiation of the synchronization technique (7 days post partum) followed by mating only at the second oestrus in January 1973 appeared to offer some encouragement. While a number (48) of ewes were induced to lamb at least once at 6-monthly intervals, only one ewe lambed four times in 24 months.
Reproduction in young female sheep induced to breed at various ages
Authors: Al-Wahab R. M. H. , Bryant M. J.
Published: September 2010

Two hundred and thirteen Suffolk × (Cadzow Improver × Scottish Blackface) young female sheep were mated either after the natural occurrence of puberty or at 140, 182 and 224 days of age in Year 1 and 140 and 182 days of age in Year 2 after treatment with progestagen (MAP) and 750 i.u. PMS; 90 to 100% of sheep ovulated after hormone treatment. Few sheep were found with embryos or live lambs in Year 1, possibly because of inadequacies in artificial insemination. In Year 2, after natural mating, the incidences of cleaved ova, live embryos 26 days after mating and live lambs born were 82, 33 and 23% respectively for sheep mated at 140 days; 100, 31 and 23% respectively for sheep mated at 182 days; and 100, 62 and 31% respectively for sheep mated after puberty. The occurrence of a second post-treatment ovulation in sheep without embryos at 26 days increased with age at treatment.
Food efficiency in relation to estimated growth of body components in cattle
Authors: Monteiro L. S.
Published: September 2010

A model is proposed to establish a functional relationship between food intake, weight gain and body composition during growth, based on the differential energy requirements for fat, fat-free tissues and contents of the digestive tract. If constant specific nutrient requirements are assumed for fat and fat-free tissues, these requirements can be directly estimated from changes in food intake and body composition during growth. By introducing an allometric function relating changes in fat-free tissue to changes in body weight, the model is extended to include situations where direct measures of body composition are not available. This enabled the model to be fitted to data on food intake, body weight and growth rate up to 2 years of age in Friesians and Jerseys fed ad libitum on a complete diet. The nonlinear model is contrasted with a linear relationship where food intake i s related to body weight and weight gain. The linear model was unable to account for the changes in food intake over the whole period of growth. The non-linear model allowed a gradual decline n i maintenance requirements per unit weight and indicated an increase in the net conversion coefficient of food into gain, consistent with an increase from early to late growth in proportion of fat deposited.

For the period studied the Jerseys were less efficient in transforming food into weight gain than Friesians. On the non-linear model, about half of the difference was attributable to the higher metabolic rate per unit weight of Jerseys, the remainder to poorer utilization of nutrients for weight gain. If, as the model indicated the conversion coefficients of food into body constituents were the same in the two breeds, the difference in efficiency may be attributable to a higher proportion of fat in the overall gain of Jerseys. The pattern of estimated fat deposition also differed in the two breeds with Jerseys appearing to be less mature in fat percentage at all stages.
Intake and live-weight gain by British Friesian calves offered different ratios of dried grass and concentrates
Authors: Marsh R.
Published: September 2010

Four experiments were carried out with calves offered pellets containing different ratios of cereal/protein concentrate and dried grass together with 10% chopped hay. Organic matter digestibility of total ration declined by 5·2 percentage units for each 25% increment of dried grass.

Dry matter (DM) intake of the total ration increased as dried grass content increased from 0 to 50% which led to similar intakes of digestible organic matter (DOM) and daily gain. When pellets contained 75% dried grass, total DM intakes were reduced in two experiments, leading to DOM intakes and daily gains similar to that of calves offered pellets of dried grass only. In the third experiment, DM intake of pellets containing 75 % dried grass was greater than the intake of pellets containing 50 to 100 % dried grass. When equal quantities of DM were offered, DOM intakes and daily gains tended to decline linearly as dried grass content in the pellet increased. The replacement value of the dried grass for concentrate at equal levels of live-weight gain was 1·36: 1.
Cycling ambient temperature effect on boar semen
Authors: Heitman H. , Cockrell J. R. , Morrison S. R.
Published: September 2010

Twenty-four 1-year-old boars of proven fertility were assigned randomly to one of two temperature-controlled trailers. A control group in each trial was held at 17 ± 0·5°C while the other group was exposed to a diurnal ambient temperature cycle. Cycles followed a sine-wave pattern with minimum and maximum temperatures occurring at 04.00 and 16.00 h respectively. Cycling temperature ranges were 17 to 33 ± 0·5°C (low-temperature stress), 19·5 to 35·5 ± 0·5°C (medium-temperature stress), and 22 to 38 ± 0·5°C (high-temperature stress). Semen samples were collected every 3 or 4 days over an experimental period of 42 days.

Low-temperature stress and medium-temperature stress boars were not affected significantly in the five parameters of semen quality observed. The difference between controls and high-temperature stress boars was highly significant for motility, abnormal spermatozoa, gel-free volume, and total spermatozoa per ejaculate. Concentration of spermatozoa was not affected by treatment. Significant time effects were observed for motility, abnormal spermatozoa and total spermotozoa per ejaculate. Significant differences began to appear after 2 or 3 weeks and changes still appeared to be occurring at 6 weeks.
Multibreed comparisons of British cattle. Variation in body weight, growth rate and food intake
Authors: Thiessen R. B. , Hnizdo Eva , Maxwell D. A. G. , Gibson D. , Taylor C. S.
Published: September 2010

A multibreed cattle experiment involving 25 British breeds was set up to study genetic variation between breeds and genetic inter-breed relationships for a wide spectrum of traits in order to examine the problems of between-breed testing and selection. The experimental design is described and results on between-breed variation are presented for four traits.

All animals were housed indoors and from 12 weeks of age were given a single complete pelleted diet ad libitum through a system of Calan-Broadbent electronic gates. Females were mated to produce one purebred and three crossbred calves, which were reared to slaughter in order to measure the efficiency of the cow-calf unit of production.

Results based on a total of 292 animals, with an average of 12 per breed, are presented for body weight, cumulated voluntary food intake, daily weight gain and daily food intake over the age range from 12 to 72 weeks. The 25 breed-mean curves for body weight and cumulated food intake displayed a remarkably uniform pattern of rankings at all ages and the rankings were very similar for both traits.

The multibreed design used was effective in estimating between-breed variation as a proportion of total variation for the four traits examined. After approximately 1 year of age, the proportion of variation between breeds was approximately 0·70 for body weight and 0·60 for cumulated voluntary food intake. Changes in these traits could therefore be brought about more effectively by selection between breeds rather than within breeds. For average daily weight gain measured over 12-week intervals, between-breed selection was estimated to be most effective in the period of maximum growth rate between 6 and 9 months of age, when between-breed variation was 0·52 of the total. For average daily food intake, measured over 12-week intervals, between-breed selection was likely to be effective beyond 6 months of age, when the proportion of between-breed variation plateaued at 0·48.

At all ages, the coefficient of genetic variation between breeds was approximately 0·14 for body weight and daily gain, and remarkably constant at approximately 0·12 for both daily and cumulated food intake. It is suggested that, for growth and intake traits, the genetic variances within and between breeds remain proportional to each other at all ages.
Effects of starling excrement in the food of cattle and pigs
Authors: Glahn J. F. , Stone W.
Published: September 2010

Livestock food was contaminated with starling excrement by placing caged starlings (Sturnus vulgaris) over livestock food troughs and feeders, and allowing starling excreta to fall on food for periods ranging from 30 to 56 consecutive days. Several levels of contamination were tested by varying the number of caged starlings over troughs, from 1 to 18 birds per m2 of trough area. During the winters of 1979 and 1980, four trials were conducted involving 78 pigs of both sexes, 24 steers and 18 male calves. No significant differences were observed in daily rate of weight gain or efficiency of food conversion (food offered per unit gain), suggesting that neither cattle nor pigs appeared to be adversely affected by exposure to starling excreta in their food. Food rejection observed during these trials appeared to be a negligible problem overall. Although limited disease incidence did occur, it did not appear to be associated with food contamination.
Aspects of reproduction in goats and sheep in south-central Kenya
Authors: Wilson R. T. , Peacock Christie , Sayers A. R.
Published: September 2010

Age at first parturition in this environment occurs at approximately 18 months. The biggest cause of variation is flock with neither species nor any other source being significant. Parturition intervals for both species are approximatley 10·5 months: flock and season are significant on this variable and there is a decreasing, although non-significant, interval with advancing age. Litter size in goats is 1·25 and in sheep is 1·04, with parity and flock having significant effects for both species, while season also has an effect on goats. Annual reproduction rate is 1·42 kids and 1·19 lambs per breeding female per year.
Factors affecting the outflow of protein supplements from the rumen. 2. The composition and particle size of the basal diet
Authors: Elimam M. E. , Ørskov E. R.
Published: September 2010

Two experiments were conducted to investigate the effect of the composition and particle size of the basal diet on the outflow of chromium-treated fish meal from the rumen of lactating British Friesian dairy cows, using Cr-concentrations in faeces. A 4 × 4 Latin square design was used and the cows were fed at twice the estimated energy requirements for maintenance in two equal meals.

Fractional outflow rates per h were, 0·079, 0·088, 0·086 and 0·064 for the 1·00 hay: 0·00 concentrate, 0·75 hay: 0·25 concentrate, 0·50 hay: 0·50 concentrate and 0·25 hay: 0·75 concentrate respectively. The difference between 0·75 and 0·50 concentrate was significant (P < 0·05).

Grinding of long dried grass through 40 or 20 mm screens had no significant effect on the outflow of Cr-treated fish meal from the rumen, however fine grinding (5 mm) and pelleting significantly reduced the outflow from rumen (P < 0·05). Fractional outflow rates per h were 0·080, 0·086, 0·088 and 0·047 for the long, 40, 20 mm and the 5 mm and pelleted diets respectively.
Reproduction in the gilt. 5. The effect of the presence of the mature male during rearing on puberty attainment
Authors: Eastham Philippa R. , Dyck G. W. , Cole D. J. A.
Published: September 2010

Forty Landrace × (Landrace × Large White) gilts were randomly assigned at 70 days of age to each of two rearing treatments. The two treatments were: (1) gilts reared with gilts but kept in complete isolation from other pigs, and (2) gilts reared with visual, aural, olfactory and limited tactile contact with a mature boar. At 160 days of age, all gilts were subjected to a pen change and housed adjacent to either a mature boar for the first time, or to a different mature boar from that with which they had contact during the rearing phase. In addition, gilts were exposed to a mature, vasectomized boar for 30 min each day. They were served twice at second oestrus and the reproductive tracts were examined at slaughter 21 days later to determine ovulation rate and embryo survival. The presence of a mature male during the rearing phase had no effect on the attainment of puberty. There were no significant differences between treatments 1 and 2 for age at puberty (168·1 and 166·9 days respectively), weight at puberty (74·0 and 75·7 kg respectively) and the interval from movement and boar introduction to puberty (8·3 and 7·4 days respectively). The rearing treatments also had no effect on ovulation rate or embryo survival.
The relations between the apparent digestibility of roughages in the rumen and lower gut of sheep, the volume of fluid in the rumen and voluntary feed intake
Authors: Ulyatt M. J. , Blaxter K. L. , McDonald I.
Published: September 2010

Three sheep with permanent fistulas of the rumen were each given dried grass and two hays, each in three different amounts, and the apparent digesti-bility of the roughages in the rumen and distal to the rumen was determined. A lignin ratio method was used to measure digestibility.

With increase in the amount of the poorest hay given, the proportion digested in the rumen fell and that distal to the rumen increased. With the second hay this effect was also noted but was not statistically significant. The voluntary intakes ofdry matter varied from 1·94 kg/day for the dried grass to 1·28 for the poorest hay. The volumes of distribution of polyethylene glycol in the rumen when feed was offered ad libitum, however, were the same, irrespective of the type of feed, at between 14·1 and 15·2 litres. These observations were confirmed at slaughter. The results support the hypothesis that sheep voluntarily consume roughages of different qualities to achieve constant fill of their rumens, and that little regulation of voluntary intake can be attributed to distension of the hind gut.
A note on the composition of live-weight gains estimated by regression analysis
Authors: McDonald I. , Kay M.
Published: September 2010

In experiments involving measurements on beef carcasses, the animals can be slaughtered at a given degree of fatness, at a prescribed live weight or at a prescribed age. The ultimate choice depends upon the purpose of the experiment but where comparisons are being made between different breeds receiving the same diet it is usual to slaughter animals at the same degree of fatness. This subjective assessment of the time at which the animals are to be slaughtered results in widely different slaughter weights and ages. In order to aid the interpretation of results, Pomeroy (1965) suggested that animals should be killed at at least three different live weights so that an estimate of the rate of change of various parameters can be derived.
A note on the selective uptake of serum proteins in piglets following dosage with porcine serum
Authors: Perry G. C. , Watson J. H.
Published: September 2010

Perry (1964) has shown that piglets failed to absorb homologousBrucella abortusantibodies, whereas they absorbed homologousSalmonella pullorumantibodies much more readily. WhenS. pullorumantibody was used, piglets showed marked differences in their efficiency of absorption. These differences existed whether the antibodies were administered in serum or in colostrum (Perry and Watson, 1967a, b). Moreover, they could not be entirely accounted for by variation in concentration of antibody in the dose, age at dosage, genetical effects or maternal effects (Perry and Watson, 1967a).
Growth promotion by oral administration of enkephalinase inhibitors (thiorphan and acetorphan) in rats and mice
Authors: Rivière P. J. M. , Buéno L.
Published: September 2010

The effects of long-term oral administration of enkephalinase inhibitors (acetorphan and thiorphan) on food and water intake, live-weight gain and food conversion efficiency were investigated in growing rats and mice. In rats, daily drenching with acetorphan (an absorbable prodrug of thiorphan) at 1 mg/kg per day for 8 days did not alter food and water consumption but significantly increased live-weight gain (32·0 (s.d. 5·1) g for control rats v. 40·7 (s.d. 9·1) g for treated rats (P ≤ 0·05 U test) and improved food conversion efficiency (4·37 (s.d. 0·49) g food per g gain for control rats v. 3·70 (s.d. 0·67) g food per g gain for treated rats). In mice, lower doses (0·2 mg/kg per day) of thiorphan and acetorphan given in the drinking water similarly affected live-weight gain (7·7 (s.d. 0·9) g v. 6·0 (s.d. 1·6) g in 3-week-old mice receiving thiorphan and 2·6 (s.d. 0·4) g in 5-week-old mice receiving acetorphan) with a likely improvement in food conversion efficiency. These results suggest that oral administration of enkephalinase inhibitors may alter growth in rodents, probably by affecting the digestive process.
A comparison of inbred and outbred sheep on two planes of nutrition. 4. A note on the effects on some blood constituents before and after exposures to acute cold or head
Authors: Wiener G. , Woolliams Carol , Slee J.
Published: September 2010

Earlier reports have shown that inbred sheep were smaller than outbreds although they grew at a similar rate (Wiener, Woolliams and Slee, 1988a), that both the effects of inbreeding and of nutrition affected cold resistance and heat tolerance (Slee, Wiener and Woolliams, 1988) and that all these factors influenced semen quality (Wiener, Woolliams and Slee, 1988b). The present report deals with a number of constituents in the blood of the same experimental animals.
Units of Account in Gold and Silver in Seventh-Century England:Scillingas, SceattasandPæningas
Authors: Hines John
Published: September 2010

The seventh-century vernacular laws from the kingdoms of Kent and Wessex specify fines or compensation payments using units of account that have given us familiar terms in the numismatics of this period:scillingas(shillings),sceattasandpæningas(pennies). In light of the use of cognate words in Gothic and Old High German, and the comparative values given in the Old English law-codes themselves and in the fifth-century Theodosian Code, it is suggested that these represent a regular and durable bimetallic system correlating values in gold and silver. This proposition is examined further against the evidence of weighing-sets from sixth- and early seventh-century Anglo-Saxon graves, and it is argued that the results give greater and more precise meaning to the use of gold and silver in Early Anglo-Saxon artefacts, such as the great gold buckle from Mound 1 at Sutton Hoo, Suffolk.
A practical assessment of early weaning
Authors: Van der Heyde H.
Published: September 2010

The rearing and economic results from normal weaning systems are highly variable; this is also true for early weaning, not only because it is a new system, but because thesystem depends more upon the farmer and much less upon the sow. Farmers like early weaning particularly because of its labour-saving aspects. In the first part of the paper I shall give a survey of the causes of differences in rearing results we have obtained from different farms and rearing centres. The second part will examine what is currently the major problem of early weaning systems, the subsequent reproductive performance of the sow.