bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of daylength on the growth of lambs 2. Blood concentrations of growth hormone, prolactin, insulin and thyroxine, and the effect of feeding
Authors: Forbes J. M. , Driver P. M. , Brown Wendy B. , Scanes C. G. , Hart I. C.
Published: September 2010

1. The levels of four hormones which might be involved in the control of growth have been measured in the blood of lambs kept in 16 or 8 h daylengths for 4 months in each of two experiments. Under the conditions of these experiments long daylength stimulated growth.

2. Prolactin concentration was significantly increased by long day-length and by ad libitum feeding, compared with short daylength and restricted feeding, respectively.

3. Growth hormone, insulin and thyroxine concentrations were unaffected by daylength. Ad libitum feeding caused lower growth hormone and higher insulin concentrations than restricted feeding, and growth hormone levels fell after the morning feed.

4. Of the hormones measured, prolactin is most worthy of further study as a possible mediator of the effects of long daylength on growth.
The effects of days-open on milk yield and on breeding policy post partum
Authors: Bar-Anan R. , Soller M.
Published: September 2010

The effects of days-open on milk yields in current lactations and in following lactations were estimated from 71 911 current and 68 693 following lactation records. Yields were expressed as 305-day, total and annual records, where annual record = 365 × (total yield/days between calvings).

The data were grouped according to current days-open, corrected for initial yield differences and analysed separately for heifers and cows in Moshav (moderate-yielding) and Kibbutz (high-yielding) herds. Current 305-day records increased by 15 to 18 kg milk/day-open up to 90 days-open, and 2 to 3 kg/day-open thereafter. In contrast, the effects of increasing days-open on annual yields were generally small and negative, being positive only for heifers up to 90 days-open. Thus 305-day records heavily under-rated annual yields of fertile cows. For current lactations, 70 to 100 days-open for heifers and 30 to 50 days-open for cows resulted in the highest annual production. Yields in following lactations were positively associated with days-open in the previous lactation. The effect was highest in high-yielding herds, suggesting that high-yielding cows respond positively to some rest between calvings.

Combining the effects of days-open on current and following lactation yields and on the calf crop: in high-yielding herds heifers had the highest productivity when mated not earlier than 70 days post partum, while in moderately-yielding herds days-open did not affect productivity. Cows in high-yielding herds achieved highest productivity at 41 to 90 days-open, while cows in moderately-yielding herds were most productive when mated as early as possible.

A comparison of the economic value of sire fertility and sire transmitting ability for milk production showed that fertility may often be over-rated.
The effects of rapid rearing and early calving on the subsequent performance of dairy heifers
Authors: Little W. , Kay R. M.
Published: September 2010

1. One-hundred-and-ten British Friesian, British Friesian × Ayrshire or successive backcrosses to British Friesian heifer calves were allocated to three groups. Groups A and B were rapidly reared and fed a barley-beef diet which resulted in mean body-weight gains exceeding 1 kg/day (13 to 39 weeks) and group C was normally reared on summer grazing and hay plus concentrates in winter at a mean body-weight gain never exceeding 0·74 kg/day. Animals in group A were first mated at an average age of 42·9 weeks (body weight, 302 kg). Groups B and C were mated later at average ages of 78·4 and 78·1 weeks (average body weights, 443 and 353 kg respectively). After the first calving all animals were fed and managed as a single group.

2. There were no significant differences between the proportion of heifers conceiving at first service in groups A (55·5%), B (66·7%) and C (72·4%).

3. There were no differences in the incidence of dystocia at first calving in heifers served by an Aberdeen Angus bull but 12 out of 19 heifers in group A served by a British Friesian bull had dystocia.

4. Average 305-day fat-corrected milk yields in the first four lactations in group A (18 animals) were 1959, 2918, 3545 and 3210 kg and in the first three lactations in group B were2450,3216and3310kgand in group C 3863,4694 and 4813 kg. Thus milk yield was significantly lower in all lactations for rapidly-reared animals irrespective of the age at breeding and was further significantly lowered in the first lactation of animals mated early.

5. There was a high incidence of laminitis and bloat in heifers reared on the barley-beef diet, but during lactation, there was a lower incidence of mastitis in the lower-yielding, rapidly-reared groups.
A comparison of two contrasting types of grain sorghum in the diet of the growing pig
Authors: Almond M. , Smith W. C. , Savage G. P. , Lawrence T. L. J.
Published: September 2010

A study was undertaken to compare the chemical composition of Texas No. 2 hybrid yellow sorghum with that of a traditional brown-seeded variety and also their digestibility and nitrogen retention in the growing pig. Dry matter, crude protein and gross energy contents and amino acid composition were similar in the two varieties but brown-seeded sorghum had a markedly higher tannin content. In diets containing 70% of either yellow or brown sorghum, N retention was marginally higher on the yellow sorghum diet and apparent digestibility of dry matter, nitrogen and gross energy was improved (0·07, 0·06 and 0·12 units respectively). The improvements in digestible energy and crude protein content of the yellow sorghum diet over the brown-seeded one were 10% and 6% respectively. In a subsequent trial 16 pigs were individually and scale-fed each of the diets over the live-weight range 28 to 81 kg. Growth rates and feed conversion ratios were better on the yellow sorghum diet (10%) but sorghum variety did not influence killing-out percentage, deposition of backfat or area of eye muscle in cross-section.
A retrospective evaluation of the weights in the cow genetic index
Authors: Brotherstone Susan , Hill W. G.
Published: September 2010

The fat plus protein yield of 70 011 records of pedigree British Friesian/Holstein cows was regressed on various components of their dam's Cow Genetic Index (CGI) in order to obtain the regression coefficients for comparison with the index weights currently used in the calculation of the CGI. For the first and later (2 to 5) lactation components of the CGI, the regression coefficients obtained by analysis were consistent with the tabulated index weights, but the coefficients for the sire component tended in some cases to be lower than the table values. The analysis was repeated using only dams that had widely used sires. The partial regression coefficients for the first and later lactation components were again consistent with the tabulated weights, and the coefficient for the sire component lay within one s.d. of the table values. In all cases, a cow's CGI is shown to take full account of her first and later lactation information and her sire's and dam's transmitting abilities.
The effect of sward height on beef cow performance and on the relationship between calf milk and herbage intakes
Authors: Wright I. A. , Russel A. J. F.
Published: September 2010

Groups of 12 spring-calving cows and their calves were allocated to each of three continuous grazing treatments: cows and calves grazed a 4- to 5-cm sward (LI), cows grazed a 4- to 5-cm sward and their calves grazed an 8- to 10-cm sward (Lh) and cows and calves grazed an 8- to 10-cm sward (Hh). In each case cows and calves grazed separately. Sward height had a large effect on both cow and calf performance and intake. The short swards reduced cow herbage intake proportionately by 0·2 compared with that of the taller sward. Cow live-weight gains were −0·60, −0·59 and 0·42 (s.e.d. 0·103) kg/day on treatments LI, Lh and Hh respectively while calf live-weight gains were 0·80, 0·95 and 1·14 (s.e.d. 0·040) kg/day. Calf milk intakes were 7·05, 5·78 and 9·34 (s.e.d. 0·508) kg/day respectively while daily herbage intakes were 17·2, 22·0 and 19·8 (s.e.d. 1·35) g organic matter per kg live weight for treatments LI, Lh and Hh. There was a negative association between calf herbage and milk organic matter intakes in the treatments where the calves had access to a more generous sward height (treatments Lh and Hh), the regression coefficient being −0·89 (s.e. 0·381), indicating the calves' ability to increase herbage intake in response to a reduction in milk intake. On the LI treatment there was no significant relationship between milk and herbage intakes. The ability of grazing suckled calves to compensate for a reduction in milk intake is thus dependent on sward conditions, and may also depend on herbage digestibility. The increase in herbage intake cannot however compensate fully for a restriction in milk supply.
Lysine supplementation of diets for pigs between 7 and 56 days of age
Authors: Leibholz Jane , Parks J. R.
Published: September 2010

Sixty entire male pigs between 7 and 28 days and 60 entire male pigs between 28 and 56 days of age were given ad libitum basal diets using peanut meal and wheat gluten with or without dried milk as the protein supplements. The diets contained between 7·0 and 10·7 g lysine per kg. These diets were supplemented with graded additions of synthetic L-lysine hydrochloride.

It was found that the lysine required for maximum performance and nitrogen retention was at least 12·7 g/kg dry matter (DM) between 7 and 28 days of age and not greater than 12 g/kg DM between 28 and 56 days of age. These values are 4·7 and 5·3 g/kg dietary crude protein for the two ages or 0·81 and 0·79 g/MJ digestible energy.

A method is discussed for the calculation of the most economical level of lysine supplementation. This is dependent on the cost of the basal diet and lysine, and the value of the weight gain.

The concentration of free lysine in the blood plasma did not give a clear indication of lysine requirement of the pigs.
Effect of ambient temperature on energy metabolism in growing pigs
Authors: Verhagen J. M. F. , Kloosterman A. A. M. , Slijkhuis A. , Verstegen M. W. A.
Published: September 2010

Group-housed young growing pigs, given food ad libitum, were exposed to two temperatures, one within thermal neutrality (25°C) and one around the lower critical temperature (15°C). Pigs at 15°C had daily gains reduced by 57 g for 6 days after initial exposure. Food intake was increased significantly after 6 days at 15°C but not at 25°C. Maintenance requirement was increased by 58 kJ/kg M0·75 and energy retained as protein was decreased by 49 kJ/kg M0·75 for the first 6 days after exposure to the treatment of 15°C and thereafter both became equivalent to those of pigs at 25°C afterwards. It is concluded that animals were acclimatized after 6 days exposure.
A note on the changes in leg weakness in pigs after being transferred from confinement housing to pasture lots
Authors: Sather A. P.
Published: September 2010

It is a popular belief, supported by several scientific studies (Vaughan, 1971; McPhee and Laws, 1976; Fredeen and Sather, 1978; Sather and Fredeen, 1982) that leg weakness will diminish in young stock of breeding age after they are transferred from confinement housing to pasture lots. However, Nakano, Aherne and Thompson (1981) working with boars from the Canadian Swine ‘Record of Performance’ (ROP) testing programme found that no improvement in gait resulted after the animals were transferred from confinement housing with solid concrete flooring to pasture lots. The number of animals in the study was limited. All of these reports dealt only with the recovery of pigs from leg weakness and did not include pigs with sound legs at the beginning of the pasture period (approx. 90 kg live weight).
A note on the performance of growing pigs given diets containing manioc
Authors: Taylor J. A. , Partridge I. G.
Published: September 2010

The potential problems concerning the use of manioc, from the processed roots of cassava (Manihot esculenta), have been reviewed by Oke (1978) and Walker (1983). Although current legislation has ensured that in recent years the levels of cyanogenic glucoside in imported cassava have been negligible (Walker, 1985), there is still conflicting evidence on the maximum level of manioc which can be included in pig diets without adverse effects on digestion and performance. In a previous study (Partridge, 1985), 300 g manioc per kg tended to increase the proportion of energy apparently absorbed from the large intestine compared with lower levels. This may have been partially responsible for some of the digestive upsets found with young pigs by O'Grady and Hanrahan (1979). Evidence of the effect of manioc on performance can be misleading due to palatability problems and therefore lower food intakes (Müller, Chou and Nah, 1975; Papodopoulos, Ziras and Kalaissakis, 1983).
Pregnancy effects on carcass and meat quality attributes of cows
Authors: Wythes J. R. , Shorthose W. R. , Fordyce G. , Underwood D. W.
Published: September 2010

The effects of pregnancy status (non-pregnant, early to mid (1 to 5 months) and late (> 6 months)) and month of pregnancy on live weight, carcass weight, dressing proportion, bruising and muscle properties were examined in 237 Shorthorn and Brahman crossbred cows (mean live weight 424 kg, 62% pregnant). The cows were transported 1155 km to an abattoir and given access to food and water until slaughter. Mustering to slaughter periods were 5, 6 or 7 days.

The mean gross hot carcass weights for the 89 non-pregnant, 108 early to mid pregnant and 40 late pregnant cows were 207, 199 and 187 kg (P < 0·05). Their respective dressing proportions were 487, 469 and 443 g/kg (P < 0·05). Among the pregnant cows, carcass weight and dressing proportion decreased by 2·95 kg and 6 g/kg, respectively, for each month of pregnancy (P < 0·05).

Cows in late pregnancy had lower mean initial yield (IY) and peak force (PF) shear values for m.longissimus dorsi (LD) than non-pregnant cows. The late-pregnant cows also had the greatest mean pH 24 h post mortem (pH24) and ultimate pH (pHu) values (P < 0·05). They also had a greater proportion of carcasses with high pHu values than the early to mid-pregnant and non-pregnant cows (0·30 v. 0·157 v. 0·079; (P < 005). Among the pregnant cows, mean pH24 increased by proportionately 0·038 and the proportion of high pH24 carcasses by 0·055 for each month of pregnancy (P < 0·05). Pregnancy status had no significant effect on mean fat depth, bruise score, PF-IY value or cooking loss.
The effect of formic acid treatment and the duration of the wilting period on the digestion of silage by young steers
Authors: Charmley E. , Gill M. , Thomas C.
Published: September 2010

Four silages were prepared from perennial ryegrass: two unwilted, ensiled either without (UWN) or with formic acid additive (UWA) and two wilted for either 19 (WS) or 43 h (WL) prior to ensiling. The influence of conservation method on digestion in the rumen and the flow of organic mater (OM) and nitrogen (N) to the small intestine was studied using young steers fitted with rumen and duodenal T-piece cannulae. The silages were well preserved and of similar chemical composition despite a 1·5-fold increase in dry matter (DM) following wilting. The unwilted silages had a higher concentration of fermentation acids and a lower concentration of soluble N in the DM. Polyester bag studies showed that significantly more DM was potentially degradable but the degradation rate was slower in the rumen of steers fed UWA and WS silages (P < 0·05), however, rate of passage was not significantly different for the four treatments. Conservation method had little effect on post-feeding rumen ammonia concentration but feeding unwilted silages caused a greater depression in post-feeding rumen pH (P < 0·05). Wilting lowered N digestibility in the whole tract (P < 0·05), but had no effect on apparent digestion or degradability of N in the rumen as measured by the polyester bag method. Apparent OM digestibility in the whole tract was lower in steers given wilted rather than unwilted silages (P < 0·05), but disappearance of apparently digestible OM in the rumen was greatest for the 19 h wilted silage (WS, P < 0·05). It is concluded that, provided unwilted silage is well preserved, the use of formic acid has little effect on digestion of silage by steers and the effects of wilting are confined to a reduction in whole tract digestibility.
The effect of a change in blood acid-base status on body composition and mineral retention in growing lambs
Authors: Damir H. Abu , Scott D. , Thomson J. K. , Topps J. H. , Buchan W. , Pennie K.
Published: September 2010

Three groups of lambs of about 25 kg live weight were given a concentrate diet either on its own (eight lambs) or supplemented with 10 g/kg ammonium chloride (eight lambs) or 20 g/kg sodium bicarbonate (12 lambs). At about 45 kg live weight the lambs were killed and their body composition was determined. The composition of their gains was also determined using information obtained from a fourth group of lambs (eight lambs) which were killed at the start of the experiment. Lambs given the ammonium chloride diet showed a reduction in blood pH while those given the sodium bicarbonate diet showed an increase to levels seen in lambs given forage diets. There were also marked effects on calcium (Ca), phosphorus (P) and magnesium retention with retentions being reduced in those given the ammonium chloride diet and increased in those given the bicarbonate diet. The average rates of retention of Ca and P in lambs given the bicarbonate diet were 9·1 and 5·9 g/kg empty-body weight gain and are comparable with rates seen in lambs given forage diets. These results suggest that dietary induced changes in blood acid-base status is a major factor contributing to the lower rates of retentions of these minerals in lambs given cereal-based diets.
A note on the effect of dietary protein concentration, sex, type and live weight on whole-body amino acid composition of the growing pig
Authors: Kemm E. H. , Siebrits F. K. , Barnes Penelope M.
Published: September 2010

Seventy-two Landrace pigs were used to study the effects of dietary crude protein concentration (197, 168 and 137 g/kg air dry meal), sex, type and live weight on the whole- body (gut content included) amino acid composition of growing pigs. Boars and gilts from two types (lean and obese) slaughtered at 20, 30 or 90 kg live weight were used. Mean whole-body amino acid concentrations were: lysine 63·4; methionine 21·8; cystine 15·8; threonine 35·1; leucine 67·7; isoleucine 28·0; valine 40·5; phenylalanine 35·5; tyrosine 24·6 and histidine 26·8 g/kg protein. Dietary protein concentration had no effect on body amino acid composition. Boar values tended to be higher than those of gilts but there were no significant differences. Pigs of the obese type also tended to have higher values than lean pigs, with significant differences obtained for methionine, cystine, leucine, and isoleucine. Apart from cystine, live weight had no effect on whole-body amino acid composition, Cystine content however, decreased highly significantly from 17·1 g/kg protein at 30 kg live weight to 14·3 g at 90 kg live weight P (P < 0·001). When compared with the suggested ideal pattern for essential amino acids leucine and histidine values are higher and isoleucine slightly lower, with no conclusive indication on methionine and cystine.
Speed of ultrasound in Hereford bulls and its correlation with carcass composition
Authors: Fursey G. A. J. , Miles C. A. , Page S. J. , Fisher A. V.
Published: September 2010

Measurements were made of the speed of ultrasound transmission through sites in the hind limbs of 125 pedigree Hereford bulls. Twenty-five of these were measured twice at weekly intervals on three occasions prior to slaughter to assess the short-term repeatability of the measurement and the magnitude of long-term changes. Analyses of variance of the means of the measurements at two sites showed that the residual standard deviation (within animal and occasion), was 0·01 (μs/cm. There was a decrease of 0·01 (μs/cm in the group mean over the 2-week period and a significant time × animal interaction. This showed that lipid concentration at the measurement sites decreased as the bulls adjusted to their new surroundings following delivery to the Institute's farm. When a separate group of 64 bulls was measured at the farm at which they were being reared an increase in the group mean of 0·006 iμs/cm was recorded over a 30·day period, indicating an increase in lipid concentration. The residual standard deviation for that group was 0·007 μs/cm, similar to that recorded above.

The mean of the reciprocal speeds at the two sites, when used in a multiple regression with live mass, yielded a residual standard deviation in predicted proportion of lean in the side of 20·0 g/kg and in total fat proportion of 22·1 g/kg. These corresponded to population standard deviations, adjusted for live mass, of 29·7 and 34·1 g/kg respectively. It was concluded that the measurement of ultrasound speed in the hind limbs of Hereford bulls could be used to predict lean proportion in the carcass. The method does not require subjective interpretation and responds equally to subcutaneous and interand intra-muscular fat.
The effects of dietary supplements of fish meal on the voluntary food intake of store lambs
Authors: Tan P. V. , Bryant M. J.
Published: September 2010

Absstract

Thirty-six male and thirty-six female lambs (mean live weight 31·6 kg) were used to investigate the effect of fish-meal supplementation upon voluntary intake of NaOH-treated straw in a 3 × 3 factorial experiment with three levels of fish meal (0, 45 and 90 g/day) and three allowances of concentrate (57, 10·0 and 14·3 g/kg live weight) (experiment 1). The fish meal × concentrate allowance interaction was significant (P < 0·05) for straw dry matter (DM), total DM and metabolizable energy (ME) intake. Thus, as concentrate allowance increased, straw DM intake remained largely unchanged when fish meal was included in the diet whereas concentrate progressively substituted for straw DM intake when fish meal was not included in the diet. Increasing concentrate levels increased total DM intake linearly for all levels of fish meal but the rate of increase was positively associated with level of fish meal.

In experiment 2, 24 castrated male lambs (mean live weight 40·7 kg) were used to measure apparent digestibilities and nitrogen (N) balance on four of the diets used in experiment 1. The overall effects of concentrate and fish-meal levels upon voluntary intake were similar to those found in experiment 1 but the interaction term was not significant either for intake or for the digestibility coefficients. Increasing fish-meal level increased apparent digestibility of DM, organic matter (OM) and aciddetergent fibre (ADF) (P < 0·01) while increasing concentrate allowance increased apparent digestibility of DM (P < 0·001) and OM (P < 0·01) but decreased that of ADF (F < 0·01). Nitrogen (N) retention was improved by the inclusion of fish meal in the diet (P < 0·001) and by high allowance of concentrate (P < 0·001).

The voluntary intake response observed in experiment 1 could not be explained by the digestibility and N balance results obtained in experiment 2.
Protein composition and variation of caprine colostrum (Murciano-Granadina breed) by means of polyacrylamide-sds gel electrophoresis
Authors: Quiles A. J. , Gonzalo C. , Fuentes F. , Hevia M. , Sanchez J. M.
Published: September 2010

The variation in the content of total protein, total casein, whey protein, α-casein, β-casein, k-casein, α-lactalbumin, β-lactoglobulin and ‘other’ whey proteins of the mammary secretion was studied in 44 goats of the Murciano-Granadina breed (Spain) from the 1st to the 4th day after parturition.

The concentration of all the protein variables showed a marked decrease from the 1st to the 4th day after parturition (P< 0·001). In whey proteins this decrease was more marked from the 1st (67·1 g/1) to the 2nd day after parturition (21·6 g/1), whereas the total caseins sharply decreased from the 2nd (62·6 g/1) to the 3rd day after parturition (39·0 g/1).

Stepwise discriminant analysis revealed that, except for the k-casein, all the proteins resulting from the electrophoretic fractionation had a discriminant power between the dates of sampling (P< 0·001). The multivariant analysis did not show statistical differences in the electrophoretic fractions corresponding to the samples on the 3rd and 4th days after parturition. According to such fractionation, the transition from colostrum to milk should take place on the 2nd day after parturition.
A note on the comparison of methods for estimating the ileal digestibility of amino acids in pigs
Authors: Leterme P. , Pirard L. , Théwis A.
Published: September 2010

A comparison was made between the Heal digestibility of the amino acids in pigs obtained by the use of a basal diet, the apparent Heal digestibility obtained with a semi-synthetic diet where peas were the sole protein source and the true Heal digestibility obtained with synthetic and nitrogen-free diets.
The effect of level of protein supplementation on the performance and carcass composition of young bulls given grass silage ad libitum
Authors: Steen R. W. J.
Published: September 2010

Two experiments have been carried out to examine the effects of the level of protein supplementation given with grass silage-based diets on the performance and carcass composition of bulls, and to compare diets based on silage and dried forage. The five treatments used consisted of grass silage offered ad libitum and supplemented with 2·5 kg dry matter (DM) of barley-based concentrates containing (1) zero (2) 200 (3) 400 and (4) 600 g soya-bean meal per kg and (5) artificially dried grass and hay supplemented with 3·2 kg concentrate DM. The silages used in both experiments were well preserved, containing on average 200 g DM per kg; 140 g crude protein (CP) per kg DM; 63 g ammonia-nitrogen per kg total N and 731 g digestible organic matter per kg DM. The bulls were of late-maturing breed type and were initially 12 months old and 412 and 405 kg live weight in experiments 1 and 2 respectively. For treatments 1, 2, 4 and 5 in experiment 1 respectively (treatment 3 was not used) total DM intakes were 8·3, 8·3, 81 and 110 (s.e. 0·21) kg/day; CP intakes 1063, 1271, 1664 and 1539g/day; metabolizable energy intakes (MEI) 98, 99, 96 and 87 MJ/day; carcass weights 317, 316, 317 and 316 (s.e. 3·2) kg; carcass saleable meat concentrations 714, 712, 718 and 716 (s.e. 5·8) g/kg and carcass fat trims 73, 81, 73 and 68 (s.e. 3·9) g/kg. In experiment 2 for treatments 1 to 5 respectively total DM intakes were 8·3, 8·5, 8·3, 8·4 and 11·2 (s.e. 0·26) kg/day; CP intakes were 1090, 1329, 1504, 1720 and 1561 g/day; MEI 102, 106, 103, 103 and 94 MJ/day; carcass weights 318, 331, 330, 327 and 321 (s.e. 3·3) kg; carcass saleable meat concentrations 726, 721, 725, 721 and 732 (s.e. 60) g/kg and fat trims 71, 77, 78, 80 and 64 (s.e. 4·5) g/kg. It is concluded that protein supplementation of a silage-based diet did not affect performance or carcass fatness in experiment 1 or carcass fatness in experiment 2, but including 200 or 400 g soya-bean meal per kg concentrate increased performance in experiment 2. Animals given silage produced fatter carcasses than those given dried forage in experiment 2 but not in experiment 1.
The effect of diet and genetic constitution on growth curves and efficiency in rats
Authors: Lozano Susana Calderari de
Published: September 2010

Equations relating biomass to cumulative food ingested ad libitum were defined in rats from weaning to 200 days of age. Two inbred lines of the IIM strain: α, of medium adult weight, and b, of low adult weight, were fed on two different diets, × and Z. The following groups were formed: αX, αZ, bX and bZ. Body weight and food intake were recorded over a 1-day period every second day. For each of the four groups, body weight, W, could be described as a function of cumulative food intake (F) by the equation:

Each exponential term was assumed to measure the behaviour of a portion of the biomass. The first exponential term implied an intense growth and a high initial efficiency, which became effectively zero by about 100 days of age. The second exponential term implied a weak growth and a low but significant efficiency of food utilization. Type of diet influenced level of intake and was important at early ages (<100 days). At 46 days of age, animals of both lines were heavier and more efficient when fed on diet Z. The genetic influence determining final adult weight becomes evident after 46 days of age.
The effect of the physical form of the diet on the consumption of solid food by calves, and the distribution of food residues in their alimentary tracts
Authors: Hodgson J.
Published: September 2010

1. British Friesian male calves were offered, in two experiments, either chopped, or ground and pelleted dried grass diets to appetite. In one experiment the pelleted diet was also given in restricted quantities. The calves were slaughtered without being fasted, 6 to 9 weeks after weaning, and detailed measurements were made of the weights and volumes of the sections of the alimentary tract and its contents, and of other abdominal organs.

2. Grinding and pelleting the diet reduced mean retention time by approximately 50% and digestibility by 6 to 8 units, and increased dry-matter intake in the two experiments by 55 or 32% respectively, and growth rate by 53 and 69% respectively.

3. The ground and pelleted diets resulted in a smaller quantity of fluid digesta in the rumen, and a much greater quantity in the abomasum and small intestine.

4. There were smaller differences between diets in the quantity of digesta in the combined caecum and colon, or in the total volume of the organs of the abdomen, than in the amount of digesta in the rumen. It is suggested that further critical studies are required upon the importance of the contents of the alimentary tract, or of the abdomen as a whole, in the control of voluntary food intake in ruminants.
A note on a urea-containing molassed sugar beet pulp product as a protein concentrate for intensively-fed Friesian steers
Authors: Fishwick G. , Fraser J. , Hemingway R. G. , Parkins J. J.
Published: September 2010

A molassed sugar beet product with 32% crude protein and containing added urea (8%), dicalcium phosphate, trace elements and vitamins was evaluated in two experiments as a protein source for intensively-fed 100 kg British Friesian steers. Comparison was made with an equal amount of crude protein supplied as a mixture of decorticated groundnut and cottonseed meals.

Both forms of supplementation equally and significantly increased live-weight gains and improved food conversion ratios compared with those recorded when the basal diet consisted of barley with no protein supplement.
A note on the effect of urea contained in a molassed sugar beet pulp cube on the voluntary intake and digestibility of oat straw by steers
Authors: Fishwick G. , Hemingway R. G. , Parkins J. J. , Ritchie N. S.
Published: September 2010

1. The effects of 0·9 to 1·0 kg molassed sugar beet pulp cubes, supplemented with minerals and vitamins and with either 0, 3·0 and 7·8% urea, on the voluntary intake of oat straw (either 2·0 or 3·0% crude protein) were measured in two experiments with 250 to 300 kg British Friesian steers.

2. Straw intake was increased by a maximum of about 20% when a total of about 165 g crude protein was supplied by the urea-containing sugar beet products.

3. In one digestibility trial conducted with 385 kg steers, the inclusion in sugar beet pulp of urea equivalent to 89 g and 169 g crude protein/day comparably and significantly increased the digestibility of dry matter and crude fibre.
A note on the effects of frequency and method of feeding milk substitute on the performance of Friesian and Ayrshire calves
Authors: Broadbent P. J.
Published: September 2010

1. Forty British Friesian and 33 Ayrshire male calves were reared on one of three treatments differing in frequency and method of feedingwhole milk and milk substitute.

2. The calves were introduced to their treatments on arrival. The Ayrshire calves were offered whole milk for 24 days as two feeds of up to 1·42 litres warm milk each (2W), or one feed of up to 2·84 litres warm milk (1W) daily, or cold milk ad libitum (AC). Thereafter they received milk substitute on one of the following regimes which were applied to the Friesian calves from arrival. The regimes were 454 g milk-substitute powder reconstituted at the rate of 158 g per litre warm water (approximately blood temperature) given in two feeds of 227 g per day (2W) or one feed of 454 g per day (1W), and milk-substitute powder reconstituted with cold water at the rate of 100 g per litre offered ad libitum (AC).

3. Calves on treatment AC had higher live-weight gains and consumed more whole milk, milk substitute and less concentrates than those on other treatments. These differences were significant. There were differences in drinking behaviour on treatment AC between Friesian and Ayrshire calves which may have been due to differences in age at the start of the experiment. Solid food intake was affected by both level and pattern of liquid milk consumption. The practical and financial implications of treatment AC are discussed.
Sire evaluation and estimation of genetic gain in Israeli dairy herds
Authors: Bar-Anan R. , Sacks J. M.
Published: September 2010

The Israeli procedure for measuring sire breeding values and genetic progress due to selection is described. The estimate of sire breeding value has two components, the current contemporary comparison (CC) and an adjustment for the average genetic deviation of the contemporaries from the original base population. The combined value is called the cumulative difference (CD). For practical purposes the CD was found to be free of the time trends observed for CC, and the residual variances of the two measures were approximately equal. The relative genetic level in any given time interval was measured by the average CD of all sires used during the period October 1964 o t January 1971 in Israel. The analysis indicates that essentially all of the progress in 122-day FCM yields was due to sire selection, whereas 60% of the progress in 305-day FCM yields was due to selection and 40% to improved management.
A note on the recovery of polyethylene particles from faeces an d rumen contents of steers
Authors: Fordyce J. , Kay M.
Published: September 2010

Two experiments were conducted with three types of polyethylene particles to establish their retention time in castrated male cattle (steers) offered diets which contained predominantly cereals ad libitum. The particles were (1) ‘Ruff Tabs’, a corrugated particle of dimension 1·27 × 0·63 × 0·95 cm3 and subsequently referred to as RT and (2) and (3) plain plastic rods of 1·27 cm length and 0·32 cm (BP) or 0·63 cm (RBP) diameter.

In the first experiment with steers weighing 170 or 260 kg, 1 kg of RT particles were excreted in the faeces at a similar rate by the steers of different weights whereas BP particles passed out in the faeces more slowly in the lighter steer.

In the second experiment 30 steers weighing 440 kg were slaughtered at 7, 14, 28 and 42 days after dosing with 1 kg of BP, RT or RBP. The recovery of RT was significantly lower (P < 0·05) than that of BP 7 days after dosing and this difference was also found at 14 and 28 days. RBP behaved like BP up to 14 days but thereafter the rate of passage of RBP was faster than tha t of BP and recovery from the rumen approached that of RT.
The effects on growth, food intake and rumen volume of including untreated or ammonia-treated barley straw in a complete diet for weaning calves
Authors: Williams P. E. V. , Innes G. M. , Brewer A. , Magadi J. P.
Published: September 2010

Two experiments were conducted using British Friesian bull calves to determine the effects on growth, food intake and rumen volume of including 0, 150, 200 or 250 g ammonia-treated (35 g/kg dry matter (DM)) or untreated barley straw per kg pelleted concentrate based on cereal. All calves received once daily 440 g milk replacer powder reconstituted in 3 1 warm water, were weaned at 56 days of age and given one of the seven pelleted diets to appetite from 14 days of age. In experiment 1, the seven diets were allocated at random to 70 calves. Food intake was increased by the inclusion of straw but there was no effect on intake of the increased concentration of straw; daily DM intake from 14 to 77 days of age was 1·36 and 1·77 kg/day respectively for diets with or without straw. From 14 to 56 days of age intake of concentrate was increased by the addition of straw but was negatively correlated with the concentration of straw in the diet. After weaning inclusion of straw, whilst increasing total intake, tended to depress intake of cereal. Treatment with ammonia increased the nitrogen concentration in the straw but had no effect on the digestibility or amount of diet consumed. After adjustment was made for gut fill, the increases in weight between 4 and 84 days of age of calves given 150, 200 or 250 g straw per kg food were 6·6, 1·2 and 1·0 kg respectively greater than those that occurred when there was no straw in the diet. DM digestibility of all diets was above 0·67 but the mean digestibility of acid detergent fibre was low (0·19). The pH and ammonia concentration of rumen liquor were low and below the optimum for cellulose digestion. In experiment 2, rumen volume was measured in vivo in a group of 24 calves given the same diets as in experiment 1. Rumen volume was increased two fold at 42 days of age by the addition of straw to the diet (5·6v.2·6 1,P< 0·001), by 87 days of age the difference was increased to 7·11, (19·0v.11·9 1,P< 0·01). When all calves were given the same diet from 91 days of age, there was no effect of previous treatment on intake or rumen volume at 147 days of age.
Fat partitioning and tissue distribution in crossbred ewes following different growth paths
Authors: Butler-Hogg B. W. , Johnsson I. D.
Published: September 2010

Forty Hampshire Down × Mule (Blue-faced Leicester cf × Swaledale 2) ewe lambs, obtained within a week of birth, were reared on milk replacer and from 6 weeks of age on a complete pelleted diet. Food intake of individual lambs was controlled to produce periods of high (H: ca. 210 g/day) and low (L: ca. 110 g/day) rates of live-weight gain from 4 to 20 and 20 to 36 weeks of age. Groups of eight lambs were slaughtered and dissected at 20 weeks having followed either growth paths H or L, and at 36 weeks having followed growth paths LL, HL or LH.

Growth path had little effect on the lean or bone content of the carcass, but had a significant effect on carcass fat content and distribution. At the same carcass weight, the ratio of intermuscular to subcutaneous fat was higher in leaner carcasses. When compared at the same weight (ca. 35 kg) but different ages (H, 20 weeks; LL 36 weeks), the slower growing LL lambs contained 1·22 kg more fat than the H lambs, primarily in the intermuscular and subcutaneous depots but also in the internal omental depot. At the same age and weight (ca. 36 weeks and 48 kg), lambs which had followed the growth path LH contained 2·5 kg more fat than lambs which had followed the HL path. These differences in fatness are thought to have come about through changes in the effective protein:energy ratio of the diet, induced by the manipulation of food intake.

Carcasses of HL lambs would be of more value to the meat trade compared with LH, since they would require less fat trimming before retail sale.
Amino acid and energy interactions in growing pigs 2. Effects of food intake, sex and live weight on responses to lysine concentration in barley-based diets
Authors: Giles L. R. , Batterham E. S. , Belinda Dettmann E.
Published: September 2010

The responses of growing pigs to dietary lysine concentration, as influenced by food intake, sex (entire male and female) and live weight were investigated in an experiment involving 128 pigs. The basal barley-soya-bean diet (14·2 MJ digestible energy (DE) per kg) was offered either ad libitum or according t o a restricted feeding scale to both sexes from 20 to 85 kg live weight. The eight dietary lysine concentrations ranged from 8·0 to 12·2 g/kg during the 20 to 50 kg phase and from 6·4 to 9·8 g/kg during the 50 to 85 kg live-weight phase. Performance was assessed by response-surface analysis based on data from successive 10-kg live-weight intervals. Regression analysis was used to assess the response of carcass lean content after slaughter at 85 kg live weight.

Daily gain of females fed ad libitum was curvilinear up to maxima of 0·72 and 0·69 g lysine per MJ DE during the 20 to 50 and 50 to 85 kg growth phases respectively. Daily gain response was small but linear up to the maximum dietary lysine concentration for all other combinations of sex and food intake.

The response of carcass lean for males given food at a restricted level was linear up to the maximum dietary lysine concentration. For males given food ad libitum, carcass lean response was curvilinear with maximum lean content attained with 0·73 and 0·59 g lysine per MJ DE during the 20 to 50 and 50 to 85 kg live-weight phases respectively. Carcass lean content of females was not affected by lysine concentration within the range used.
A note on the use of a categorical variable to explain seasonality deviation from the lactation curve
Authors: Goodall E. A.
Published: September 2010

The addition of a categorical variable to the lactation model of Wood (1967) has been shown to be useful in the explanation of seasonality of milk production using data from an experimental herd. The technique is further investigated using monthly milk-yield data from 43 commercial herds in Northern Ireland in the years 1978 to 1982. Coefficients, d, of the categorical variable were estimated for each month of calving. The maximum value of d was 0·256 for the month of October and the minimum value was 0·022 for the month of March.
The effects of a combined androgenic-oestrogenic anabolic agent in steers and bulls 1. Growth and carcass composition
Authors: Fisher A. V. , Wood J. D. , Whelehan O. P.
Published: September 2010

Twenty-one pairs of male cattle twins, 10 of which were monozygotic, were used in a study of the effects of a combined implant of trenbolone acetate (140 mg) and oestradiol-17B (20 mg) on growth and carcass composition. There were three comparisons within pairs: (1) between bulls and steers (no implants); (2) between bulls and implanted steers; and (3) between bulls and implanted bulls.

Implants were given twice, at 44 to 73 days and at 300 days of age. Animals were slaughtered at 400 days following recorded consumption of a complete pelleted diet given ad libitum. Carcasses were separated into tissues and lean and fat were chemically analysed. The effects of castration and/or implantation on growth and carcass composition were assessed by comparison with the untreated (control) bull values within each group and expressed as a ratio (treatedxontrol). These ratios were then compared between groups.

Bulls were significantly heavier than steers at slaughter (29·6 kg, P < 0·05), but were not heavier than implanted steers. Implantation of steers tended to increase appetite; it proportionately increased lean and protein production by about 0·1, and partly reversed the effects of castration on the length of limb bones and the weights of reproductive organs and hide. The proportions of carcass tissues were very similar in the untreated and implanted steers. In bulls, implantation increased the weight of fatty tissue in the subcutaneous and intermuscular depots, but it had small effects on other carcass characteristics.
The influence of degree of adaptation to tether-housing by sows in relation to behaviour and energy metabolism
Authors: Cronin G. M. , van Tartwijk J. M. F. M. , van der Hel W. , Verstegen M. W. A.
Published: September 2010

In response to tethering, many sows develop seemingly non-functional repetitive behaviour (stereotypies), which may be performed for several hours in a day.

The quality and quantity of activity performed by sows with different degrees of adaptation to tethering was studied in relation to energy expenditure. Three groups of five sows were recognized: (1) High, sows which showed a high incidence of stereotyped activity after prolonged tethering; (2) T/Low, sows with limited experience of tethers; and (3) G/Low, the same sows as in group 2 after regrouping.

High sows were about three times more active than T/Low sows: the proportions of time involved in 24 h were 0·35 and 0·13 respectively. Most of the former sows' activity was in the form of sterotypies. The activity level of the G/Low sows was between that of the two tether treatments (proportionately 0·17 of 24 h). Both tethered treatments spent proportionately about 0·05 of 24 h in using drinkers compared with proportionately less than 0·02 of the time for the G/Low sows.

High sows produced proportionately 0·36 more heat than T/Low sows during the 12-h light period in each day. During this period, proportionately 0·40 and 0·20 of heat production from High and T/Low sows was associated with activity. The diurnal activity of the G/Low sows was associated with proportionately 0·24 of heat production.

Stereotypies and excessive drinker use accounted for proportionately 0·86, 0·52 and 0·24 of the activity of High, T/Low and G/Low sows. The proportions of metabolizable energy intake required for these activities were 0·23, 0·07 and 0·04 respectively for the three treatments. The study concludes that tethering is stressful when sows develop, and then indulge in frequent coping behavioural patterns which increase metabolic rate.
A note on the supplementation of low-protein, maize-soya-bean meal diets with lysine, tryptophan, threonine and methionine for growing pigs
Authors: Russell L. E. , Easter R. A. , Gomez-Rojas V. , Cromwell G. L. , Stahly T. S.
Published: September 2010

An experiment conducted at two experimental stations was designed to identify the limiting amino acids in maize-soya-bean meal diets with 120 g crude protein per kg given ad libitum to pigs from 20 to 40 kg body weight. The effects of additions of tryptophan and of tryptophan plus threonine in both the presence and absence of added methionine were studied. The responses to supplemental amino acids were not significantly different at the two stations (P > 0·10). The addition of tryptophan tended to improve growth rate. However, significant improvements in rate and efficiency of gain were not realized until both tryptophan and threonine were added (P < 0·05). Interactive effects between supplemental amino acids on pig performance were not detected. Thus, the maize-soya-bean meal diet with 120 g crude protein per kg and given ad libitum to 20-kg pigs appeared to be limiting in lysine, tryptophan, threonine and possibly methionine.
Heterogeneity of variance amongst herds for milk production
Authors: Brotherstone Susan , Hill W. G.
Published: September 2010

Estimates were obtained of the variability among herds of dairy cattle of the standard deviation (s.d.) and coefficient of variation (CV) of milk, fat and protein yield. For fat yield, for example, the mean s.d. within herds for heifers was about 30 kg, the s.d. among herds was 5·2 kg and the mean and s.d. of CV were 0·15 and 0·026, respectively. Correlations of both s.d. and CV were high between both heifers and cows in the same herd and year and between heifers or cows in the same herd in successive years, showing that variability was consistent over time and over age groups.

Ways of correcting for the heterogeneity of variance for use in cow index calculations are suggested; because CVs are heterogeneous, simple log transformation is not sufficient.