bluuebunny/crossref_metadata_2025 huggingface dataset:
Sexual maturity and spermatogenesis under heat stress in the bovine
Authors: de Alba Jorge , Riera‡ Simón
Published: September 2010

Results are presented of an investigation in which 10 bull calves were subjected to heat stress in a climatic chamber from 26 weeks of age to the age of puberty. A similar group of 8 calves sired by the same bull were simultaneously subjected to ambient temperatures in another chamber. Maximum temperature in the hot chamber was 35–36° C. for 8 hours daily and maximum temperature in the temperate chamber was 27° C.

Observations were made on weight and age at puberty and characteristics of the first five ejaculates obtained from each bull. Post-mortem examinations included: carcass weight, weight of all genital organs, measurement of sperm reserves in testicles and epididymides and histological observations of the seminiferous tubules. The results indicated that the hot temperature exposure retarded fertility but that libido was exhibited at essentially the same intensity by both groups. The quality of semen obtained and the concentration of the spermatozoa were much lower in the bulls subjected to the hot environment during their growth period prior to puberty. The poor quality of semen was associated with impaired spermatogenesis.

It is recommended that in all fertility studies conducted with exotic breeds in the tropics, semen of known uniform quality be used. Natural service should not be used.
The nutrition of the early-weaned calf VI. The effect of supplemental lysine and methionine on the utilisation of groundnut protein
Authors: Preston T. R. , Whitelaw F. G. , MacLeod N. A.
Published: September 2010

1. Nitrogen balance studies have been conducted on eight early-weaned calves receiving four diets containing, respectively, groundnut meal, groundnut+lysine, groundnut+lysine+methionine and white-fish meal as the major protein source.

2. There were no significant differences between groundnut meal diets i n any of the measurements examined. On the fish meal diet all measures of nitrogen retention tended to be higher than the corresponding values for groundnut meals.

3. Daily live-weight gains were significantly higher on the fish meal diet than on any of the groundnut diets (P<0·05).

4. It is suggested that the supplementary amino acids, being highly soluble, were rapidly deaminated by rumen micro-organisms.
The nutrition of the early-weaned calf VII. The relative value of four different fish meal products as the major protein source in the diet
Authors: Whitelaw F. G. , Preston T. R. , MacLeod N. A.
Published: September 2010

While it is generally agreed that fish meal protein is of high biological value for non-ruminants, variations in quality are known to occur as a result of differences in the nature of the parent material (Duckworth, Woodham and McDonald, 1961) or in the method of processing (Grau et al., 1959; Ousterhout and Snyder, 1961). Duckworth, Woodham and McDonald (1961) have shown that the Gross Protein Value offish meals can range from 92 to 119; within this range white-fish meals had a mean value of 102 while the mean value for herring meals was 113. Differences of a similar order have been reported by other workers (Record and Bethke, 1933; Heiman, Carver and Cook, 1939; Robertson, Carver and Cook, 1940; March, Stupich and Biely, 1949; Carpenter, 1954; Carpenter, Ellinger and Shrimpton, 1954; Duckworth, 1955).
Genetic relations between milk and beef characters in dual-purpose cattle breeds
Authors: Mason I. L.
Published: September 2010

It has been estimated (Mason, 1963) that about 70% of beef stores bred in Britain are out of dairy cows. Some 30–40% of them are by beef bulls, so that about 40–50% of animals slaughtered for beef are of pure dairy breeding.
An analysis of pre-weaning deaths in rabbits with special emphasis on enteritis and pneumonia. I. Non-genetic sources of variation
Authors: Rollins W. C. , Casady R. B.
Published: September 2010

Non-genetic sources of variation in pre-weaning death losses due to enteritis or pneumonia have been investigated using records of 15,329 rabbits born during the years 1946–61 in the random bred colony at the U.S. Rabbit Experiment Station at Fontana, California. Under consideration were periods of years, season within years, litter size, parity of doe, and fostering.

For enteritis there was a statistically significant effect of season due to a negative regression of death rate on ambient temperature. For pneumonia, periods of years were statistically significant due to an increase in later years in deaths during the first 14 days of life. The other sources of variation studied were of negligible importance.
The effect of age, live-weight and rate-of-gain on dressing percentage and non-saleable fat content of Israel-Friesian bull calves
Authors: Levi D. , Soller M. , Shilo A.
Published: September 2010

Data were collected during 1961–2 on the live-weight, age and warm carcass weights of 83 lots of Israel-Friesian bull calves, 525 animals in all, the offspring of 26 sires. For varying numbers of these animals weight of various non-saleable fat components, including ruminal fat, kidney fat, inguinal fat and scapular fat were also obtained. Ruminal fat alone and ruminal fat plus kidney fat were found to be highly correlated with total non-saleable fat (r = 0·84 and 0·94, respectively). Heritability of dressing percentage was 0·20, of live-weight rate-of-gain 0·92, and of carcass rate-ofgain 0·49. The genetic correlation between live-weight and carcass weight was 0·7. Between-lot correlations indicated that increased rate-of-gain achieved through management will be accompanied by decreased dressing percentage and increased non-saleable fat content.
A comparison of the body size, fleece weight and maternal performance of five breeds of sheep kept in one environment
Authors: Wiener Gerald
Published: September 2010

Female sheep of five breeds (Scottish Blackface (B), South Country Cheviot (C), Welsh Mountain (W), Lincoln Longwool (L), and Southdown (S)) were purchased as lambs of 5–6 months old and subsequently kept as a single flock on a grassland farm until they were 4½ years old (Southdowns to 3½ years). The sheep were used in a crossbreeding experiment with up to six breeds of ram.

The sheep were weighed and 8 body parts measured at frequent and regular intervals. The Blackfaces and Southdowns grew, relative to their mature size, a little faster initially than the Cheviots. Mature weights (lb.) were approximately B: 146, C: 145, W: 101, L: 197 and S: 129. The breeds differed in conformation but the order of maturity of the body parts was the same for each breed. Variances for body measurements decreased slightly with increasing age for early-maturing parts and increased a little for later parts. The coefficients of variation decreased slightly with increasing age. Variance in weight increased markedly with age (but not the C.V.) and showed the only large breed differences in variance.

Fleece weight, after the first shearing, was strongly affected by the amount of wool shed prior to shearing. Shedding differed significantly between the breeds, Cheviots shedding most. Shedding was also related to the number of lambs born per ewe. The total weights (lb.) of wool produced from four shearings were B: 23·2, C: 20·0, W: 15·6, L: 55·5 and S (estimated from 3 shearings): 20·8.

The numbers of lambs born per ewe totalled over three lamb crops were B: 5·81, C: 5·21, W: 4·53, L: 4·85 and S (estimated from two crops): 4·55. In survival to weaning, single-born lambs were no better than twins and crossbred lambs no better than purebred. Lambs born to Welsh mothers had the best survival; the other breeds did not differ significantly from each other. The breeds of ewe differed in the proportions of their twin lambs which had to be assisted at, or soon after, birth.

When each breed of ewe was mated to the same breeds of ram, the weights of lambs born to Blackface mothers did not differ significantly at birth from those of lambs born to Cheviots but were heavier at weaning. Lambs from Welsh mothers were the lightest at birth and weaning.

In relation to (live-weight)0·73 the maternal performance of the Welsh females was at least as good as that of the Blackfaces but the wool production was slightly poorer.
The effects of environmental temperature and method of feeding on the performance and carcass composition of bacon pigs
Authors: Holme D. W. , Coey W. E.
Published: September 2010

A trial designed to investigate the effects of two environmental temperatures, three feeding regimes and the interactions between them is described. A temperature of 72° F. was better than one of 54° F. for bacon pigs between 40 lb. and 200 lb. weight. The higher temperature resulted in faster growth, more efficient feed conversion and increased length of carcass. Other carcass characteristics were not significantly altered. Ad libitum feeding resulted in faster growth and fatter carcasses than restricted feeding, but did not have a significant effect on efficiency of feed conversion. When feed intake was restricted, feeding pigs once daily or twice daily resulted in similar performance and carcass composition.

There was a significant interaction between environmental temperature and feeding method for average daily gain in that pigs fed ad libitum grew faster at the low temperature and pigs fed restricted amounts of feed grew faster at the high temperature. No other interaction reached significant levels.
A note on correlations between milk production and milk composition of sows and the growth and haemoglobin of their pigs
Authors: Veum T. L. , Pond W. G. , Van Vleck L. D.
Published: September 2010

Total milk yield of sows is positively correlated with litter size (Bonsma and Oosthuizen, 1935; Wells, Beeson and Brady, 1940; Smith, 1952; Allen and Lasley, 1960) even though the amount of milk obtained by each pig decreases with increasing litter size. Positive correlations between sow milk yield and the creep feed consumption of her litter and between weaning weight and milk production have been reported by Bonsma and Oosthuizen (1935), and by Allen and Lasley (1960). Braude (1964) has comprehensively reviewed the literature on the associations between litter size, birth weight and weaning weight. Ward, Rempel and Enfield (1964) reported a positive correlation between weaning weight and post-weaning growth rate in swine.
A note on the effect of Scotch grain distillers' solubles on the milk production of dairy cows
Authors: Castle M. E. , Drysdale A. D. , Watson J. N.
Published: September 2010

Scotch grain distillers' solubles, known commercially as ‘Scotaferm’, are now available in Great Britain, and feeding trials were made to investigate the value of this material in the diet of the dairy cow. The solubles are a free-flowing light-brown powder produced by evaporating and then spray-drying the liquor (‘spent wash’) remaining in the whisky still after distilling the spirit. The analysis of a typical sample is 5% moisture, 29% protein (20% digestible protein as estimated by pepsin digestion), 9% fat, 5% crude fibre, 11% ash and 41% nitrogen-free extract. The food is a good source of B-vitamins and contains 3·8% calcium.
A note on the sucking behaviour of twin lambs reared as singles
Authors: Ewbank Roger , Mason Agnes C.
Published: September 2010

The suggestion has been made (e.g. Anon, 1961; Brown, 1964; Spedding and Brown, 1961; Wixey, 1965) that a method of overcoming the inability of ewes to rear twin lambs well, may be to wean one lamb out of each pair at 2–4 weeks of age. The weaned lamb would be reared on concentrates and/or grass, and the remaining lamb, which would have access to the entire milk supply of the ewe, might then show a similar rate of growth to that of a lamb reared as a single from birth. Studies have also been made of the effect of the removal of one lamb out of twin pairs at 9 weeks of age (Cunningham and Maxwell, 1966) and at 12–16 weeks of age (Cunningham, 1964).
A note on copper sulphate in the diet of pigs
Authors: Berek G. , Urbanyi L. , Lakatos T.
Published: September 2010

Braude (1965) has recently reviewed the literature on the subject of supplementation of rations for growing pigs with copper, and concluded that as much as 0·1% copper sulphate could be added to the feed without toxic effects, and that this increased growth rate by about 8·1% and improved efficiency of feed conversion by about 5·4%. Both these values are average responses from a very large number of experiments. Similar results have been reported from the Soviet Union by Volkopjalov, Lebedjeva, Spiridonova and Matuskova (1962).
Prediction of the voluntary intake of food by dairy cows: 2. Lactating grazing cows
Authors: Curran M. K. , Holmes W.
Published: September 2010

Individual observations made in different weeks of lactation (WL) of live weight (LW, lb), milk yield (MY and FCM, lb/day), age (years) live-weight change (LWC, lb/day) and digestibility of the organic matter consumed (D, %) were used to produce models pre-dicting organic-matter intake (OMI, lb/day), digestibleorganic-matter intake (DOMI, lb/day) and faecal output (lb OM/day) in 72 grazing cows (Analysis A). Estimates of herbage availability (HA, lb dry matter/cow per day) applicable to 44 of the cows, together with the above variables were used in a similar manner (Analysis B). The multiple regression methods of analysis were applied solely to between-cow observations by selection of a single set of data from the many available for each cow.

FCM and LW0·73 gave better results than MY and LW, and together with age, were all significant variables for the prediction of the dependent variable. HA was not a significant source of variation, D was only effective in models of DOMI and faecal output, and stage of lactation was not considered a consistently useful variable. The application of the multiple regression technique to the problem of partition of nutrients and the prediction of intake is considered. Precision of prediction is discussed in terms of tolerance limits for predicted values, and it is concluded that the lack of accuracy of measurement of intake in the individual grazing cow is the major obstacle to the accurate prediction of intake in grazing cows.
Litter productivity in Large White pigs: 1. The relative importance of some sources of variation
Authors: Strang G. S.
Published: September 2010

Data from 38000 Large White litters farrowed in 146 British herds were analysed to investigate the relative importance of various sources of variation affecting litter productivity. The effects of the season and the year of farrowing were very small relative to the effect of the herd of farrowing which was particularly large on the litter and average pig weights at three weeks. There was a small increase in the size of gilt litters as the age of the gilt at first farrowing increased. Litter size increased progressively with parity up to around the fourth litter and then declined gradually at higher pari-ties. There was a suggestion that the sire of a litter may hve a very small effect on litter size at birth but not at three weeks or eight weeks.
Litter Productivity in Large White Pigs: 2. Heritability and repeatability estimates
Authors: Strang G. S. , King J. W. B.
Published: September 2010

Estimates of the heritability, the repeatability and the genetic cor-relation coefficients of litter performance traits were calculated from data on 38000 Large White litters farrowed in 146 British herds.

The repeatability estimates of number of live pigs per litter at birth, three weeks and eight weeks were 0·15, 0·14 and 0·14 respectively. The corresponding heritability estimates were 0·07±0·02, 0·07±0·02 and 0·09±0·03, respectively. The repeatability estimates of litter weight at three weeks and eight weeks were 0·15 and 0·04, while the corresponding heritabiUty estimates were 0·08±0·02 and 0·03±0·02. High positive genetic and phenotypic correlations were obtained between litter size and litter weight.

A number of model culling schemes were considered and it was found that even at relatively high culling levels the improvement in overall herd mean performance was very small. Direct selection for litter size may yield a useful rate of improvement if selection is con-fined to one trait and large selection differentials are achieved, but could not be economically justified.
The rumenitis and liver abscess complex and vitamin A status in beef cattle
Authors: Rowland A. C.
Published: September 2010

The seasonal incidence of rumen and liver lesions is recorded in traditional and in intensively managed cattle, together with the vitamin A status of the two groups. Rumen lesions were observed to reach a peak in the late winter and early spring in traditional cattle, at which time the liver vitamin A levels fell to the lowest point; liver lesions reached a peak in the late summer. No specific trend was observable in rumen and liver lesions in the barley beef group. The mean levels of vitamin A were approximately one-third of those shown by the traditionally managed animals.

It did not prove possible using the agglutination test to identify the sera of animals showing active hepatic necrobacillosis at the time of slaughter.
The effect of energy, protein and vitamin supplementation on the performance and voluntary intake of barley straw by cattle
Authors: Lyons T. , Caffrey P. J. , O'Connell W. J.
Published: September 2010

1. Daily allowances of 1·37 kg of concentrates, containing either 8·9 (treatment A), 13·6 (B), 19·1 (C) or 29·2% crude protein (D) were given to 40 individually-fed steers eating long barley straw to appetite over a 112-day winter feeding period. Voluntary straw intake on treatment B was 25% higher than that on treatment A. There were no signiicant differences in straw intake between treat-ments B, C, and D. Mean daily live-weight gains (kg) for the treatment groups were A, −0·22; B, 0·05; C, 0·04; D, 0·15. When the animals were turned out to pastore, group A showed very rapid compensatory growth, and it was concluded that this was mainly due to differences between the groups in their changes in alimentary tract contents. Vitamin A and D supplementation did not affect straw intake or performance.

2. When the above supplements were given to steers in metabolism crates receiving barley straw in restricted or unrestricted quantities, it was found that an increase in the crude-protein content of the supplement significantly increased the digestibility of the organic matter, crude fibre and crude protein of the whole diet when straw intake was restricted, and significantly increased the digestibility of crude fibre and crude protein when straw was unrestricted.

3. It was concluded that voluntary straw intake was limited, at the lowest level of supplementary protein, by a deficiency of absorbed protein. At the higher levels of supplementary protein, intake was probably limited by the capacity of the alimentary tract.
Fish-protein hydrolysate as a substitute for milk protein in calf feeding
Authors: Dodsworth T. L. , Owen J. B. , Mackie I. M. , Ritchie A. , Ørskov E. R.
Published: September 2010

Two milk replacers identical in composition except for the protein source, which was either fish-protein hydrolysate (FPH) or dried skim milk, were offered either twice or four times daily to castrated British Friesian male calves in four ratios: 100 FPH 0 Milk; 67 FPH 33 Milk; 33 FPH 67 Milk and 0 FPH 100 Milk. Concentrates and hay were offered ad libitum, and the calves were weaned at 42 days of age. Feed intake and calf live weight were recorded to 100 days of age.

There were no differences in growth rate up to weaning due to frequency of feeding. Up to 67% FPH there were no differences in growth rate but calves on the 100% FPH diet showed a 40% depression in growth compared with the other three levels. Up to 100 days there was no apparent effect of treatment on live-weight gain, but only differences of 12 to 13% would be significant.

The results indicate that at least two-thirds of the milk protein could be replaced by FPH. The need for further work using dried material and FPH from other species is discussed.
A note on the effect of Probioticum feed additive on the live-weight gain, feed conversion and carcass quality of bacon pigs
Authors: Burnett G. S. , Neil E. L.
Published: September 2010

1. Two experiments were conducted, one with pigs fed individually on a restricted scale of feeding, and one with pigs fed ad libitum in groups, to test Probioticum as a feed additive with and without nitrovin and zinc bacitracin.

2. Growth rate, feed conversion, killing-out percentage and carcass quality were measured.

3. No significant difference was shown in any of the characteristics measured between diets containing any of the additives, singly or in combination.
A note on transferrin genotypes and their relationship with weight gain in sheep
Authors: Rahman M. F. , Konuk T.
Published: September 2010

Body weights were recorded at birth, 45 and 90 days on 199 Merino lambs. Serum samples were obtained and analysed with horizontal starch gel electrophoresis to identify the transferrin types. Sixteen transferrin phenotypes, TfAA, TfAB, TfAM, TfAD, TfAE, TfBB, TfBM, TfBD, TfBE, TfMM, TfMD, TfMS, TfME, TfDD, TfDE and TfEE were detected in this study. The phenotypes were confirmed on the basis of international nomenclatures. Lambs were grouped according to their transferrin types. The average weight of different groups at birth and the weight gains in the first and second 45-day periods were estimated. TfDE was the poorest weight gainer but the differential value was significant only in the second 45-day period.
A note on the effect of diet on the inoculum used in digestibility determination in vitro
Authors: Nik-Khah A. , Tribe D. E.
Published: September 2010

The in vitro dry-matter digestibilities (IVDMD) of three rations containing different proportions of hay and a mixed concentrate (pellets) were each determined by fermenting the feeds with inocula obtained from rumen contents of sheep fed on either the hay, hay and pellets, or pellets. These inocula had no significant effect on the IVDMD which averaged 60·9, 68·8 and 77·8% for the hay, hay and pellets, and pellets respectively.
Studies of pedigree Hereford cattle breeding. 1. Herdbook analyses
Authors: Özkütük K. , Bichard M.
Published: September 2010

1. Analyses were based mainly upon entries in Volume 101 of the Hereford herdbook (horned section) for 1971, but also used details published between 1900 and 1970.

2. During the calving period July 1969 to June 1970, 2705 herds in Great Britain and Eire registered 17 297 calves. It was estimated that there were some 21 900 cows in pedigree herds; 2664 bulls were used for pure breeding, more than half in one-sire herds. During the period 1964 to 1970 approximately 60% of all bull calves registered by about 6 mo of age were later licensed for pure- or crossbreeding.

3. From a sample of calves, 87% of their sires and 37% of their dams had not been bred in the same herds where the calves were registered. More than half the herds had been established for fewer than 10 yr and the average age was 12·2 yr. The mean generation interval was 5·25 yr.

4. Pedigree analyses revealed a particularly well developed hierarchy within the breed; the effective number of herds at the great-great-grandparental level was only four. The dominant herd (Vern) had made a total genetic contribution to the breed of over 24% judged by the number of independent occurrences of Vern animals in the four-generation pedigrees of sample animals. The average increase per generation in inbreeding over the past 12 generations had been only 0·48%, and there was no evidence of any subdivision of the breed into separate strains.
The response of early-weaned pigs to various protein levels in a high energy diet
Authors: Campbell R. G.
Published: September 2010

Thirty-six male piglets weaned at 20 days of age were allocated to an initial slaughter group and to five dietary treatments with proteinlevels of 15·0, 17·2, 19·1, 21·4 and 23·2% crude protein at a common energy level of approximately 3·6 Meal digestible energy/kg. All diets were offered ad libitum and growth response was compared between 5 and 20 kg and 10 and 20 kg live weight. In both periods there were significant improvements in growth and the food conversion ratio from 15·0 to 17·2%, and 17·2 to 19·1% crude protein. Between 10 and 20 kg live weight dietary protein levels above 19·1% were associated with a depression in growth. Carcass protein increased and ether-extractable material decreased with increased dietary protein over the entire range studied. Retention of digestible nitrogen was maximized on the lower protein diets. Conversion of food into carcass lean was maximized on the two highest protein diets.
Mating behaviour and testis growth of Finnish Landrace, Tasmanian Merino and crossbred rams
Authors: Land R. B. , Sales D. I.
Published: September 2010

Twenty-one of 23 Finn and 23 of 28 Finn-Merino crossbred springborn males mated at about 6 mo of age during their first breeding season, whereas all of nine Merino males did not do so until the second breeding season at about 18 mo of age. The diameter of the testes of Finn and crossbred males at 6 mo of age was a higher proportion of their diameter at 18 mo than was that of the Merinos. Seasonal studies showed an earlier increase in the testis diameter of Merino males than that of the Finns or crossbred. At all seasons, the intensity of mating behaviour of Merinos was lower than that of the other breed types.

The results support the hypothesis that the reproductive activity of males is correlated with that of related females, and the use of male reproductive activity as a criterion for genetic selection for that of the female is discussed.
Interrelationships between physical and metabolic control of voluntary food intake in fattening, pregnant and lactating mature sheep: a model
Authors: Forbes J. M.
Published: September 2010

A model has been developed in which the voluntary food intake of sheep is related directly to metabolizable energy requirements unless physical or endocrine limitations intervene.

Although no ‘set point’ for body weight or body fat is incorporated in the model, mature sheep offered food ad libitum are predicted to reach eventually a plateau of body weight due to progressive depression of gut capacity by the increasing volume of abdominal fat. The final body weight is proportional to the digestibility of the diet. During pregnancy and lactation metabolic, physical and endocrine factors interact in such a way as to give predicted patterns of feed intake similar to those observed in practice with several qualities of diet.
Meat production from pigs which have farrowed. 3. The effect of weaning-to-slaughter interval on food utilization and carcass quality
Authors: Brooks P. H. , Smith D. A.
Published: September 2010

Twenty-eight Landrace × (Landrace × Large White) young female pigs (gilts) were allocated to one of four treatment groups at about 75 kg live weight. The gilts were mated at second oestrus and suckled their piglets for 35 days. Gilts were slaughtered 14, 21, 28 or 35 days after weaning. The ‘effective’ food conversion ratios (i.e. total gilt plus litter feed intake (kg) divided by total gilt weight gain plus litter weaning weight) of the four groups were 5·22; 4·70; 4·62; and 4·56 respectively. The differences were not statistically significant.

Neither carcass weights nor individual joint weights were significantly affected by treatment. Samples of 11 middle sections from the 14-, 21- and 28-day slaughter groups were boned and cured. Bacon produced from the streak blocks had poor colour, texture and moisture-holding capacity. It was concluded that streak blocks from gilts that had farrowed were unsuitable for curing as streaky bacon.
Index selection for both current and future generation gains
Authors: James J. W.
Published: September 2010

When economic returns from current and future generation gains are comparable in magnitude, selection decisions should take account of both sources of gain. A combined selection index is devised to maximize the present value of discounted returns from all sources. The index depends on genetic and phenotypic variances and covari-ances, population structure, discount rate and the relation of annual returns to individual traits. The combined index can be regarded as the sum of separate indices maximizing returns from each source. The method is illustrated with a simple example using wool weight and body weight in sheep.
The relationships between pre- and post-weaning growth traits in lambs of Iranian fat-tailed sheep and their crosses with Corriedale and Targhee rams
Authors: Farid A. , Makarechian M.
Published: September 2010

The pre-weaning records (birth weight, weaning weight and gain from birth to weaning) of 291 male and female lambs and the post-weaning records (body weight, feedlot gain and food conversion) of 136 male lambs were used to study relationships between different traits. The lambs were derived from three fat-tailed Iranian sheep breeds (Karakul, Mehraban and Naeini) and their crosses with Corriedale and Targhee rams. All lambs were weaned at 75 + 5 days of age and the males were fed in a feedlot for 100 days after weaning. Feedlot measurements were taken at 20-day intervals.

Weaning weight and pre-weaning average daily gain showed positive and significant associations with birth weight. Birth weight, weaning weight and gain from birth to weaning were positively associated with body weight at subsequent ages in feedlot as well as with final weight (P<0·01). Birth weight, weaning weight and pre-weaning average daily gain were positively and significantly associated with total feedlot gain.

Of the different traits, total gain during the first 20 days in feedlot (adjust period) had the lowest and total gain during the second 20 days had the highest association with total feedlot daily gain. There was no evidence that the heavier lambs at weaning and those showing high growth rate before weaning, were more efficient in the feedlot. Gain during the second 20-day period in the feedlot had a significant negative association with the total food conversion (unit food/unit gain) and therefore was a good predictor for food conversion.

When the feedlot period was divided into two 40-day periods, it was found that gain during both had a significant negative association with the corresponding food conversion. A similar association was observed between total feedlot gain and food conversion, indicating that the rate and efficiency of gain improved simultaneously.
Chemical processing of wheat straw and cotton by-products for fattening cattle 3. Performance of animals receiving material in complete feeds
Authors: Levy D. , Holzer Z. , Folman Y.
Published: September 2010

The fibrous roughages, wheat straw (WS) and cotton stalks (CS), were left untreated or treated with 30 g sodium hydroxide per kg, and residual alkali was either neutralized with sulphuric acid or left unneutralized. All roughages were pelleted and used either in complete feeds or separately. The effects of these treatments on the nutritive value of the roughages were examined in digestibility trials in vitro and in vivo, and in a 7·month feeding trial of a factorial arrangement of 2 × 3 × 2, in which the roughages constituted 350 g/kg of the diets. Approximately 150 g/kg of the neutral-detergent fibre (cell wall) constituents of both roughages was solubilized by sodium hydroxide treatment, while the changes in acid-detergent fibre components (cellulose and lignin) were much smaller, although evident.

In vitro-dry matter digestibility of wheat straw was 22 % higher than that of cotton stalks, and its increase due to NaOH treatment was 50% and 30% for wheat straw and cotton stalks, respectively. In vivo digestibility of organic matter of wheat straw was increased from 0·47 to 0·59, and that of cotton stalks from 032 to 037. The increase was evident in all components except protein, in which digestibility was reduced. The increase in the metabolizable energy values of wheat straw from 6·86 to 7·45MJ/kg dry matter and that of cotton stalks from 4·77 to 5·10MJ/kg dry matter following sodium hydroxide treatment was not reflected in daily live-weight or carcass-weight gain in the feeding trial. The animals offered NaOH-treated roughages had significantly more fat trim, and more fat in the large depots. Including roughages in complete feeds revealed no advantage in metabolizable energy conversion into live weight.
Pre- and postnatal study of the carcass growth of sheep. 2. The cellular growth of adipose tissues
Authors: Broad T. E. , Davies A. S. , Tan G. Y.
Published: September 2010

The diameter of adipocytes from subcutaneous, intermuscular and internal cavity fat depots of 5 pre- and 14 postnatal Romney female sheep was measured, the volume calculated, and the number per depot computed from the weight of triglyceride in the depots.

The rates of increase of adipocyte volume relative to the increase in weight of total side adipose tissue, and of the fat depots and their chemical components, were calculated using linear regression analyses of the natural logarithmic transformed data. These logarithmic regression equations were used to estimate the volume of adipocytes in sheep at different stages of development. The total numbers of adipocytes at each stage of growth were estimated using linear double logarithmic regressions of adipocyte number on carcass weight.

The growth of total adipose tissue and of each of the fat depots occurred mainly by an increase in the adipocyte volume, which increased over 70-fold from 120 days gestation to 5 years of age. The increase in adipocyte volume during growth occurred at similar rates in all of the fat depots and no significant differences between the volumes of adipocytes from the fat depots were found within sheep of similar carcass weight. During the same growth period the total number of adipocytes increased about 6-fold. Differences in the relative rates of growth of the fat depots were attributed to cellular multiplication rather than to cellular enlargement.
A note on effect of starvation on the bovine alimentary tract and its contents
Authors: Bass J. J. , Duganzich D. M.
Published: September 2010

Fifty-one cattle were allocated into five groups varying in time of starvation (0, 17, 24, 41 and 48 h). Most of the loss in fasted live weight, stomach and intestinal contents occurred within 24 h. Weights of water, dry matter and potassium present in the stomach showed a significant decrease in the first 24 h, although the percentage of water in the stomach contents rose slowly over a 48-h period. It is suggested that cattle from pasture need be starved for no more than 24 h to minimize the effect of gut fill for body composition studies.
The intake and performance of ewes offered concentrates and grass silage in late pregnancy
Authors: Orr R. J. , Newton J. E. , Jackson Caroline A.
Published: September 2010

Masham ewes carrying single, twin or triplet foetuses were offered a ration of concentrates which increased from 200 to 650 g per ewe per day over the last 7 weeks of pregnancy in 2 years. Silage was offered ad libitum and the voluntary intake of each ewe was measured. In the first year, 30 ewes were offered a poorly-preserved, wet silage (A) which had a low digestibility, followed by a better-preserved silage (B) which had a higher digestibility and dry-matter concentration. There was an increase in silage intake when the change was made from A to B. In the following year, 32 ewes were offered silage (C) which was well preserved, similar in digestibility to B but with a lower dry-matter concentration. The ewes ate more silage organic matter (g/kg live weight) with C than A (12·77 v. 9·34) in weeks 15 to 17 of pregnancy but more of B than C (13·76 v. 10·38) in weeks 19 to 20. Ewes carrying single lambs ate more silage and had a slower rate of decrease in silage intake when the concentrate ration was increased as pregnancy progressed. As litter size increased there-was either greater loss or smaller gain in body condition score.
The effects of the frequency of feeding concentrates on milk production and eating behaviour in Ayrshire dairy cows
Authors: Gill M. S. , Castle M. E.
Published: September 2010

Two separate experiments were conducted with 12 lactating and four non-lactating Ayrshire cows to compare three frequencies of feeding concentrates per day. Milk production was measured in a 16-week experiment in which the lactating cows were given either a low- or a high-protein concentrate 2, 4 or 22 times (×) per day. Eating behaviour was measured in a 15-week experiment in which the non-lactating cows were also given the low- and high-protein concentrates 2 and 22 × per day. The low- and high-protein concentrates had concentrations of 128 and 202 g crude protein/kg dry matter respectively. Grass silage with a digestibility of organic matter in the dry matter of 0·655 was offered ad libitum to all the cows. Frequency of feeding had no significant effects on silage intake, total nutrient intake, milk yield and live weight. The milk fat concentration increased as the frequency of feeding increased but none of the differences in this and the other milk constituents was significant. Total eating time per day and eating and ruminating time per kg dry matter were not significantly different on the 2 × and the 22 × feeding treatments. There were no interactions between the feeding-frequency treatments and the two types of concentrates. It is concluded that there were no advantages in offering concentrates in more than two separate feeds per day when the daily amount averaged about 7 kg per cow and good-quality silage was available ad libitum
Gestation period, litter size and birth weight in the goat
Authors: Amoah E. A. , Bryant M. J.
Published: September 2010

Data from 265 female goats (does) from seven herds in Year 1 and 130 does from four herds in Year 2 were analysed using a general linear interactive model for factors affecting gestation period (GP), litter size (LS) and birth weight (BW) of offspring (kids). Gestation period could be described by the regression equation GP = α – 0·890LS –1·072S where S is the proportion of male kids in the litter and the constant (a) depends on breed and herd and was 154·240 (s.e., 0·843) days for British Saanen does in Herd 1. The model established for LS was a quadratic regressional relationship LS = a – 0·000103 (MW - 60))2 + 0-0172 (MW -60) where MW was live weight of the doe at mating and a at MW = 60 kg depends on herd and period of kidding. For early-kidding does in Herd 1 a was 2·277 (s.e., 0·090) kids. The expression BW —α 0·363LS + 0·057P is a simplified multiple regressional form involving BW, LS and parity (P) where a varies according to breed, herd and age of the doe. The estimate of a for kids from British Saanen, 1-year-old does in Herd 1 was 3·879 (s.e., 0·632) kg.
The effect of trenbolone acetate on growth rate and carcass composition of young female rabbits
Authors: Lobley G. E. , Walker A. , Connell Alexmary , Galbraith H.
Published: September 2010

1. Eighteen New Zealand White × Califomian young female rabbits (does) were paired by weight and age and, at 800 g live weight, placed on a restricted intake based on the mean body weight of each pair. On attaining 1 kg one of each pair was then given 10 mg trenbolone acetate by injection on days 1, 3 and 5 of each week. This continued until the animals reached 2·3 to 2·4 kg (5 to 6 weeks).

2. There were no differences in digestible or metabolizable energy intakes between treated and untreated rabbits. However, the treated animals showed small but significant increases in rates of gain for live and empty body weight compared with control does. Treated animals also had significantly more nitrogen (P < 0·001) and less energy (P < 0·05) per unit empty body weight than controls. Although the proportion of total nitrogen retention was 0·19 greater (P < 0·001) in treated does, total energy retention was only slightly less. Treated animals had approximately 40 g (200 g/kg) less fat and 50 g more protein (N × 6·25) than control does at the end of the trial.

3. Increases in liver weight and clitoral size were observed in treated animals.
The influence of boar-related odours on puberty attainment in gilts
Authors: Kirkwood R. N. , Hughes P. E. , Booth W. D.
Published: September 2010

Three experiments employing 40, 39 and 15 Large White × (Landrace × Large White) gilts respectively were carried out to investigate possible primer pheromone activity (i.e. regulating endocrine systems) for those 16-androstene steroids with known signalling pheromone activity (i.e. immediate behavioural effects) in the pig. Experiment 1 consisted of groups of prepubertal gilts exposed to one of the following odour sources (a) 5α-androstenone (5α-androst-16-en-3-one), (b) 3α-androstenol (5α-androst-16-en-3α-ol), (c) a mixture of both steroids, and (d) a diethyl ether extract of boar submaxillary salivary gland. Age at the onset of puberty in these gilts was compared with that in an unstimulated control group. Experiment 2 was similar to Experiment 1 except that the steroids were used at a higher concentration (100 fold), and a fifth group of gilts was exposed to an intact boar. In the third experiment, age at the onset of puberty was noted following exposure of groups of gilts to one of the following (a) a castrated boar which had received long term injections of testosterone, (b) urine from an intact boar, (c) an intact boar.

The results confirmed that the intact boar accelerates puberty in gilts. Although there was no conclusive evidence indicating that isolated boar odours had an effect on the onset of puberty, it is noteworthy that of those gilts exposed to 3α-androstenol, more reached puberty earlier than control gilts. However there is the possibility that transportation may have enhanced the earlier puberty found in some of the gilts taken to a source of 3α-androstenol. Prolonged treatment of a castrated boar with testosterone did not maintain its ability to accelerate puberty in gilts.
The interaction between dietary fibre level and protein degradability in dairy cows
Authors: Garnsworthy P. C.
Published: September 2010

A trial was performed to investigate the interaction between energy and protein source for cows in negative energy balance. Six cows were assigned to each of four types of concentrate (metabolizable energy (ME) 12 MJ/kg dry matter (DM), crude protein (CP) 180 g/kg DM) with low or high fibre contents (LF or HF) and protein degradability (LD or HD). For groups HDLF, LDLF, HDHF and LDHF respectively, acid-detergent fibre contents (g/kg diet DM) were 69·2, 66·1, 117·5 and 113·3; protein degradability values were determined as 0·78, 0·61, 0·72 and 0·66. Low-fibre diets were given at the rate of 11 kg/day concentrates with 6 kg/day hay (ME 8 MJ/kg DM, CP 84·5 g/kg DM) and high-fibre diets at the rate of 10 kg/day concentrates with 7·5 kg/day hay from weeks 4 to 13 of lactation. Cows were given a standard diet over the first 3 weeks of lactation and performance in week 3 was used as a covariate.

Milk yield was not affected by treatment but the butterfat content of milk from cows given the high-fibre diets (44·9 g/kg) was higher than the low-fibre diets (36·4 g/kg; P < 0·01), which resulted in significant differences in fat-corrected milk yield (HDHF: 25·1, LDHF: 26·2, HDLF: 22·7, LDLF: 21·5, s.e.d. 1·5 kg/day). ME balance was lower for the LDHF group (−4·1 MJ/day) than for groups LDLF and HDLF (-15·4 and -16·8 MJ/day; P < 0·05) but was not significantly different from the HDHF group (-29·4 MJ/day). Undegradable protein (UDP) balances were 53·4, 93·8, -21·2 and 193·8 (s.e.d. 45, P < 005) g/day for groups HDLF, LDLF, HDHF and LDHF respectively. Differences from zero in ME and UDP balance were accounted for in all groups except LDHF by changes in live weight plus a systematic correction of approximately 10 MJ/day. It is considered that the cows given high-fibre diets responded to high UDP by increasing fat-corrected milk production but mobilization of body fat to support this increase was accompanied by retention of protein with associated water, resulting in very little change in live weight. It is also probable that the high UDP levels improved the digestion of fibre i n the rumen, but this is unlikely to have been sufficient to have accounted for all of the response.
Components of environmental variance of yields of cows in different lactations
Authors: Brotherstone Susan , Hill W. G. , Thompson R.
Published: September 2010

With a view to incorporating identifiable environmental factors such as month of calving as random effects in models for dairy sire and cow breeding value estimation, an analysis was undertaken of environmental components of variance for fat yield in lactations 1 to 5 of pedigree British Friesian-Holstein cattle. Records of fat yield and of log fat yield on daughters of widely used sires were first corrected for age and month of calving and for sire in each lactation on a national basis. Variance components for herd-year, herd-year × lactation, herd-year × month of calving, herd-year × month of calving × lactation and error were then estimated for pairs of lactations.

The results were most consistent for log fat yield, where heterogeneity of variance was less. Correlations were, approximately, 0·45 and 0·42 for records in the same herd-year and lactation for lactation 1 or a later lactation, respectively, and approximately 0·40 for records in the same herd-year and different lactations. Within herd-year and lactation, correlations of records in the same month were approximately 0·10 for lactation 1 and 0·08 for later lactations, and for different lactations the correlations were 0·06 if lactation 1 was included and 0·08 otherwise. Thus, the effects appear to be similar for later lactations, which can be pooled, but effects for month and month × lactation 1 v. later should be fitted.
The effect of supplementary light on the production and behaviour of dairy cows
Authors: Phillips C. J. C. , Schofield S. A.
Published: September 2010

In experiment 1, 12 cows (treatment L) received natural daylight (mean 8 h), 10 h supplementary light (mean intensity 481 lux) and dark (mean 6 h), and 12 cows (treatment N) received natural daylight (mean 8 h) and dark (mean 16 h) for 8 weeks. Supplementary light increased milk yield and tended to increase food intake and loss of live weight. There were no significant effects on milk composition although milk fat concentration tended to be reduced for cows in treatment L. Daily feeding times were not affected by treatment although more feeding took place during the supplementary light in treatment L. Supplementary light increased the time spent lying down per day and reduced the distance walked per day, although cows in treatment L spent less time lying during the light supplementation period. In both treatments, the activity rate was increased on the day of oestrus, but in treatment L the incidence of oestrus-specific behaviour was significantly reduced compared with treatment N.

In experiment 2, 16 cows received natural daylight (mean 9 h) and 10 h supplementary light of mean intensity 0, 101, 191 or 529 lux in a change-over design. There were no significant effects of supplementary light or its intensity on the food intake, milk yield or live-weight change of the cows, but milk fat concentration was reduced for cows receiving supplementary light at 101 or 529 lux and milk protein concentration was reduced for cows receiving light at 529 lux.