bluuebunny/crossref_metadata_2025_split huggingface dataset:
Amino acid requirements of growing pigs. 6. Isoleucine
Authors: Taylor S. J. , Cole D. J. A. , Lewis D. 
Published: September 2010

ABSTRACTThe response of the growing female pig (25 to 55 kg live weight) to increasing dietary isoleucine supplies at two levels of dietary leucine was assessed by measurement of growth rate, food utilization, tissue deposition as indicated by ham dissection and changes in plasma urea concentration. A range of isoleucine concentrations from 3·7 g/kg to 5T g/kg of the diet was derived from a basal diet and seven increments of L-isoleucine. Synthetic L-leucine was added to the basal diet to increase the concentration from 12 g/kg to 15 g/kg to achieve the two levels. The basal diet was formulated using barley, maize, blood meal, yeast protein, fat and tapioca with synthetic amino acids included to maintain at least 9·5 g/kg lysine and adequate concentrations of other essential amino acids and non-essential nitrogen. The 16 diets were replicated four times and fed to 64 female growing pigs once daily according to a restricted feeding scale. Blood samples were taken from each pig at 40 kg live weight for the determination of plasma urea nitrogen.The addition of synthetic leucine to the basal diet had no consistent effect on growth performance or carcass quality, although it did result in elevated levels of plasma urea nitrogen. The response of growth performance and the composition of the ham joint to increasing dietary isoleucine concentration was interpreted by broken line functions which indicated an isoleucine requirement of 4·4 to 4·5 g/kg of the diet.
Influence of anabolic treatments on luteinizing hormone and testosterone secretion in bulls
Authors: Fabry J. , Renaville R. , Burny A. 
Published: September 2010

ABSTRACTFourteen growing Belgian White Blue bulls were assigned to three groups: five controls (C); five bulls implanted with 140 mg trenbolone acetate and 36 mg Zeranol (TBA-Z); and four bulls implanted with 140 mg trenbolone acetate and 20 mg oestradiol-17β (TBA-E2). Testosterone (T) and luteinizing hormone (LH) levels in blood plasma were determined at day 0, 30 and 60. Mean plasma LH concentrations measured by repeated sampling over a 10-h period were similar at day 0, 30 and 60 in the three groups. At days 30 and 60, T levels were significantly lowered in treated bulls: namely 2·0 (s.d. 0·7) μg/1 v. 2·7 (s.d. 0·5) μg/1; 0·7 (s.d. 0·1) μg/1 v. 1·0 (s.d. 0·3) μg/1; 0·5 (s.d. 0·1) μg/l v. 0·4 (s.d. 0·2) μg/1 in the C, TBA-Z and TBA-E2 groups respectively. Moreover, anabolic compounds completely abolished pulsatile liberation of LH and T.In control bulls intravenous injection of 0·5 ng/kg body weight of LH releasing hormone (LHRH) caused the release of a large quantity of LH (10 to 13 times the basal level after 10 min) followed by an increase in plasma T levels. On the other hand, LH and T responses to LHRH were reduced by TBA-E2 and TBA-Z treatments. A delay in LH response to LHRH was apparent 6 days after anabolic treatment. However, the total amount of LH liberated during the test was increased. The second effect was a quantitative reduction at days 20, 30 and 60 in LH and T secretion after LHRH. The modification of the hormonal pattern was quicker and more pronounced in TBA-E2 than in TBA-Z animals. Correlation was negative (r = −0·68; P < 0·05) between the mean daily gain during the experimental period and the total quantity of T liberated by the testis after LHRH stimulation at day 60. It was concluded that administration of trenbolone acetate plus Zeranol or trenbolone acetate plus oestradiol-17β in pubertal bulls reduced the LH and T responses to LHRH and abolished the pulsatile LH and T secretions.
The behaviour of calves at market
Authors: Carson Katherine , Wood-Gush D. G. M. 
Published: September 2010

ABSTRACTA study was made of the behaviour of young calves at two Scottish auction markets, Lanark and Stirling, and an experiment was conducted to assess the effect of an auction market on the behaviour of calves less than 1 week old.Several features of the marketing procedure were identified as causing the calves distress, mainly because the calves were unable to lie down and rest. Crowding of calves in the pens, movement to different pens, and penning of very young calves with older calves were the three main reasons why calves could not rest. The older calves (approx. > 10 weeks) were more active, running and jumping around the pens and disturbing the very young animals which stood up in response to being trodden on.Crowding was severe in some pens although there was no clear evidence to show that small groups of calves (6 to 10 calves) in small pens rested more than calves in large groups (20 to 50 calves) in larger pens.Calves showed their distress initially by calling loudly, looking wildly around their new environment and sometimes by running around the pen and calling. As time passed behavioural signs of distress were less prominent and calves assumed a ‘depressed’ posture with their heads low, ears held back, tails clamped down and with their weight distributed more on their hindlegs than on their forelegs.Calves subjected to an experimental market showed similar signs of distress to those calves in the real markets, whereas control calves rested for more than 0·74 of the same time. Experimental calves which were subjected to a journey of 2.5 h were less easily disturbed from the lying posture at the experimental market than calves which had undergone a journey of 15 min only.
Heritability estimates of wool follicle traits in sheep skin
Authors: Abouheif M. A. , Johnson C. LeRoy , Botkin M. P. 
Published: September 2010

ABSTRACTData were collected from 600 newborn lambs, offspring of 354 Western crossbred ewes and 26 rams, to determine heritability estimates as well as phenotypic and genetic correlations between wool follicle variables using histological techniques. Breed of sire and sire within breed were significant sources of variation in total and secondary wool follicle populations and secondary:primary (S:P) ratio. Heritability estimates calculated by regression of offspring on dam were slightly higher than by paternal half-sib correlation or regression of offspring on sire. Expressed as an average of the three methods of calculation, the heritability estimate for S:P ratio was highest (0·69), followed by estimates for secondary, total and primary wool follicles (0·52, 0·46 and 0·36, respectively). These estimates are similar to the heritabilities of fleece weight, staple length and fibre diameter. Selection for increased density, provided an accurate measure is used, is suggested as an effective means for increasing fleece weight within grade.
On selection among groups with heterogeneous variance
Authors: Hill W. G. 
Published: September 2010

ABSTRACTProblems of making selection decisions among animals from several environmental groups with heterogeneous variance are discussed. Unless correction for heterogeneity of variance is made, animals will tend to be selected from the more variable groups, especially if selection is intense. This is an accurate and fair procedure only when the heterogeneity reflects real differences in heritability. It is shown that, if observations are expressed as deviations relative to the estimate of standard deviation from the group, the accuracy is high unless groups are very small.
A comparison of silage-based and dried forage-based diets, and the effect of protein supplementation of a silage-based diet for finishing beef cattle
Authors: Steen R. W. J. , Moore Charlotte A 
Published: September 2010

ABSTRACTAn experiment was carried out to compare silage-based and dried forage-based diets for finishing beef cattle and to examine the effects of protein supplementation and formaldehyde treatment of silage on performance and carcass composition. The four diets used consisted, on a dry matter basis, of (1) 700 g/kg formic acid-treated grass silage and 300 g/kg low protein cereal-based concentrate (LPC), (2) 720 g/kg formic acid-treated silage and 280 g/kg high protein cereal/fish meal concentrate, (3) 600 g/kg formaldehyde-treated silage and 400 g/kg LPC, and (4) 480 g/kg artificially dried grass and grass hay and 520 g/kg LPC. The silages were well preserved with 33 to 40 g ammonia N per kg total nitrogen. The diets were offered to 40 British Friesian castrated male cattle which were initially 387 (s.e. 2·9) kg live weight. For diets 1 to 4 respectively metabolizable energy intakes were 91·8, 94·7, 94·9 and 91·8 MJ/day; total nitrogen intakes 192, 234, 189 and 191 g/day; live-weight gains 0/89, 0/93, 0/86 and 0/82 (s.e. 0/045) kg/day; carcass gains 0·51, 0·52, 0·52, 0·52 and 0·50 (s.e. 0·33) kg/day; mean subcutaneous fat depths 5·6, 5·4, 5·3 and 6·0 (s.e. 0·41) mm; marbling scores 3·0, 3·3, 3·2 and 2·6 (s.e. 0·19) and areas of m. longissimus dorsi 65·7, 66·4, 64·7 and 64·3 (s.e. 1·66) cm2. It is concluded that performance, efficiency of energy utilization and carcass fatness were similar for a diet containing 700 g/kg well preserved grass silage and a dried forage-based diet with a similar intake of energy and protein. Protein supplementation of a diet based on formic acid-treated silage or formaldehyde treatment of silage did not affect performance or carcass fatness.
Pulsatile secretion of oestradiol-17β in post-partum dairy cows
Authors: Peters A. R. , Perera B. M. A. O. 
Published: September 2010

ABSTRACTThirteen dairy cows between 7 and 20 days post partum were fitted with catheters in both the jugular vein and caudal vena cava, the latter with the tips anterior to the junction with the ovarian veins. Blood samples were taken from nine control cows from both sites at 15-min intervals for periods of between 8 and 16 h. Four more cows were sampled for 13 h and given 4 × 2·5 ug GnRH intravenously at 3-h intervals starting 1 h after sampling began. Plasma oestradiol-17(3 concentrations were significantly higher in the vena cava than in the jugular vein in the two cows in which they were compared. Twenty-eight LH pulses occurred in the nine control cows during the sampling periods. These were followed within 1 h by increases in caval oestradiol-17β concentrations in 26 cases. LH pulses occurred after 14 of the 16 GnRH injections and with one exception were associated with oestradiol pulses in the vena cava. Oestradiol concentrations generally peaked 15 to 45 min after each LH peak. It is concluded that ovarian follicles are responsive to LH pulses by releasing oestradiol pulses early in the post-partum period.
Growth and carcass performance of British Landrace pigs heterozygous at the halothane locus
Authors: Simpson S. P. , Webb A. J. 
Published: September 2010

ABSTRACTThe effects of the halothane gene on growth and performance were estimated from British Landrace positive and negative selection lines and crosses between the lines. A total of 214 full-sib pairs were performance tested from 25 to 85 kg live weight on either ad libitum or scale (0·69 g/g ad libitum food intake) feeding. Half-sides of 45 carcasses were fully dissected.In the crosses, growth and performance did not depend on whether the sire or the dam was from the positive line. Carcass length, conformation score, eye muscle area and incidence of pale, soft, exudative meat (PSE) were all intermediate in the crosses. Given food ad libitum, the crosses had increased appetite and growth rates which resulted in increased backfat depths. However, in the fully dissected carcasses, the crosses were intermediate for lean proportion. Although the crosses gave a net economic advantage, the incidence of PSE may be unacceptably high for commercial exploitation.
An investigation of the repeatability of eight measurements of beef carcasses
Authors: Bodwell C. E. , Everitt G. C. , Harrington G. , Pomeroy R. W. 
Published: September 2010

1. Three measurements on both sides of 15 carcasses and 5 additional measurements on bot h sides of 6 carcasses were taken in duplicate by 3 observers working independently. The carcasses, which ranged in weight from 520 to 884 lb., were measured from 2 to 6 hr. after slaughter while on the hook in the chill-room of a slaughter-house.2. Length of body and loin were the measurements which could be taken the most consistently, whereas the 2 depth measurements and the length of tibia were the least repeatable.3. For 2 measurements, there were marked differences between observers i n the average differences between sides. In all carcass investigations, measurements should be taken on both sides and averaged.4. For all measurements, except the length of body and loin, there were differences in the average values found by the 3 observers.5. It is suggested that to achieve a satisfactory degree of repeatability, slight redefinition and clarification of the points of reference is required for some measurements, whereas others may have to be discarded.
The effects of inbreeding on carcass traits in the bacon pig
Authors: King J. W. B. , Roberts R. C. 
Published: September 2010

Carcass measurements made on 1,463 Large White pigs from 88 inbred lines, at various degrees of inbreeding, have been analysed.Partial regression coefficients calculated within lines showed that each 10% increase in inbreeding coefficient significantly increased carcass weight by 0·46 lb., decreased mid-back fat thickness by 0·37 mm. and streak thickness by 0·36 mm.Partial regression coefficients calculated on all the material, or on line means showed, however, that the most highly inbred pigs tended to be shorter and fatter than average. Possible explanations of this finding are discussed and it is suggested that under the selection procedure adopted for litter size and weaning, weight favours the survival of these less desirable lines.
The relative influence of birth weight, milk consumption and supplementary food consumption upon the growth rates of suckling piglets
Authors: Lodge G. A. , McDonald I. 
Published: September 2010

1. Data from 208 piglets in 24 litters were examined to evaluate the relationships of weights at 3 and 8 weeks with birth weight and milk consumption within litters, and with these and creep-feed consumption between litters.2. Of the total variation in 3-week weight within litters, 39% was associated with variation in birth weight, 67% with variation in milk consumption to 3 weeks, and 80% with these two factors combined. Of the total variation in 8-week weight within litters, 30% was associated with variation in birth weight, 25% with variation in milk consumption to 8 weeks, 42% with these two factors combined and 45% with variation in 3-week weight.3. Of the total variation in 3-week weight between litters, 6% was associated with variation in birth weight, 15% with variation in milk consumption to 3 weeks, and 18% with these two factors together. These values were all too low to be statistically significant, as were the equivalent relationships with 8-week weight. Of the total variation in 8-week weight between litters, 77 % was associated with variation in creep-feed consumption to 8 weeks, 70% with variation in 3-week weight, 85% with consumptions to 8 weeks of milk and creep-feed combined, and 89 % with creep-feed consumption to 8 weeks and 3-week weight combined.4. The practical significance of these relationships is discussed.
Potassium and hypomagnesaemic tetany in calves
Authors: Blaxter K. L. , Cowlishaw B. , Rook J. A. F. 
Published: September 2010

1. Four groups of four calves were given rations containing adequate and inadequate amounts of magnesium, both with or without an excess of potassium, added as potassium chloride.2. The excess of potassium resulted in the death of three of the eight calves, the clinical signs observed before death being cardiac insufficiency, oedema, severe muscular weakness and muscular atony. The excitability of motor nerves, measured by the method of Kugelberg (1944), was reduced by excess dietary potassium and the serum concentration of potassium was increased. The potassium content of the erythrocytes declined with age, irrespective of dietary treatment.3. Although this evidence of potassium intoxication was obtained, no concomitant abnormalities were induced in magnesium metabolism by the excess of potassium whether or not the calves received rations containing adequate or inadequate amounts of magnesium.4. Excess potassium had no effect on the concentration of potassium or magnesium in the muscle or on the Ca : Mg ratio in bone.5. Magnesium deficiency resulting in tetany was shown to have no statistically significant effect on the intracellular concentration of magnesium i n the muscle. A very small drop in erythrocyte magnesium was noted. No effect on the excitability of motor nerves was observed.6. The results suggest that the effect of excessive manuring of pastures with potassic fertiliser in increasing the incidence of hypomagnesaemic tetany is not due to a direct effect of potassium on the magnesium metabolism of the animal.
A note on the effect of inbreeding on lamb weights of Sardinian sheep
Authors: Dassat P. , Sartore G. 
Published: September 2010

An analysis was made of the effect of inbreeding in Sardinian sheep from the records of 658 single female lambs born in the Monastir flock in the years 1935–42 and 1947–55.The calculations of differences between inbreds (both 12·5% and 25%) were done within recording years. The results showed that inbreeding had no significant effect on birth weight or 30-day weight.
The effects of oral and implanted hydroxyzine on growth, endocrine and carcass characteristics of lambs
Authors: Preston T. R. , Charleson Euphemia B. , MacLeod N. A. , Rosen G. D. , Vernon J. 
Published: September 2010

1. The results of four experiments on the effects of oral and implanted hydroxyzine on lambs are reported.2. The effect of hydroxyzine on daily rate of live-weight gain ranged from +7·8% to −6·2% improvement with a mean value of +2·3%.3. Lambs receiving hydroxyzine in the creep feed manifested significantly higher killing-out percentages and lower thyroid weights than the controls. Pituitary weights were not affected by hydroxyzine.4. In an experiment on individually-penned, weaned wethers, given a high energy diet, hydroxyzine by either route did not affect live-weight gain but significantly increased killing-out percentage, rate of gain of carcass weight and fat deposition in certain tissues. Hydroxyzine did not affect the fresh weights of the pituitary, thyroid and adrenal glands or the weights of the teats.
The influence of contemporaneity, genetic variation and herd differences on variation in milk yield and butterfat percentage
Authors: Watson J. H. 
Published: September 2010

1. Paired lactation records of milk yield and fat percentage from experimental twins and commercial twins, full-sisters and half-sisters are used in a study of the influence of contemporaneity, genetic variation and herd differences.2. The design of the investigation was such that members of a pair were alike in:(i) both time of calving and lactation number,(ii) time of calving only,(iii) lactation number only, or(iv) neither time of calving nor lactation number.3. Intra-class correlations between pair members in respect both of yield and fat percentage were highest for contemporary records. Differences in time of calving and in lactation number produced, in aggregate, a decline in correlation of about 20%. However, the separate estimates varied considerably between the different types of pair.4. The within-pair and between-pair variance components independently confirm these effects of contemporaneity. As the degree of contemporaneity of pair members declines the within-pair variance increases in size and the between-pair component decreases.
The effect of hexoestrol on the eating quality of beef and lamb
Authors: Preston T. R. , Greenhalgh Isoline , Boyne A. A. , Crichton J. A. , Rolfe E. J. , Brown Agnes , Dodsworth T. L. 
Published: September 2010

There were no differences in toughness, juiciness, intensity of flavour and incidence of taints between samples of meat from wether lambs and cattle which had been treated with oestrogens and similar meat samples from untreated controls.During feeding trials prior to slaughter both the cattle and sheep which had been given oestrogens gained in live-weight significantly faster than their respective controls.
Influence of natural service on length of oestrus in the cow
Authors: de Alba Jorge , Corta Eduardo Villa , Ulloa Gustavo 
Published: September 2010

Observations on duration of the period of receptivity in two groups of Milking Criollo, one of Jersey and one of Brahman cows are presented. After one or two oestrus periods measured without service the cows were bred naturally in the case of Jerseys, Brahmans and one group of Milking Criollos. In the other group of Milking Criollos, artificial insemination was used. The period of receptivity was shortened after natural service by 8·7 hours in Milking Criollo and by 4·1 hours in Brahman cows. No shortening of oestrus occurred in the Jerseys and no significant shortening in artificially inseminated Milking Criollos.Nine of the cows under observation (and seven other cows with some Zebu blood) allowed only one service by the bull.
The requirements of bacon and heavy pigs for certain essential amino acids
Authors: Bellis D. B. 
Published: September 2010

The requirements of bacon and heavy pigs for lysine and methionine have been investigated. The trials employed 3rd and 4th cross Large-White × Essex pigs.In the first trial, which involved 560 pigs during the 40 to 120 lb. growth stage, the amount of herring meal in the standard weaner diet was progressively reduced from 7 to 1%. Total protein was kept constant by including soyabean and groundnut meal.Growth efficiency worsened progressively as herring meal was reduced but growth was restored by adding lysine and methionine to the levels of the 7% herring diet. The optimum levels of lysine for pigs during the 40 to 120 lb. growth stage appeared to be higher than reported elsewhere (0·85% against 0·76% and 0·65%).Treatments prior to 120 lb. had no residual effects on growth during the 120 to 200 lb. stage when all pigs were on a normal fattening diet containing no animal protein and there were also no residual effects on the carcass composition of the pigs at 200 lb. live-weight.The results support the view that the nutritional value of animal proteins to pigs lies solely in the quantity of essential amino acids that they supply. Under the conditions of this trial, the particular essential amino acids were lysine and methionine.The second trial involved 260 individually and group-fed heavy pigs. Lysine supplementation of the barley-mineral diet during the 140 to 260 lb. growth stage improved food conversion and increased the lean content of the carcasses of heavy pigs fedad lib.; with restricted feeding growth rate was also improved.Under the conditions employed the optimum lysine content of heavy pig diet during the final growth stage is at least 0·67%.