bluuebunny/crossref_metadata_2025 huggingface dataset:
The relationship in ewes between voluntary food intake during pregnancy and forage intake during lactation and after weaning
Authors: Foot Janet Z. , Russel A. J. F.
Published: September 2010

(1) Voluntary intake of forage was measured in 31 Scottish Blackface ewes for the last 14 weeks of pregnancy, throughout lactation, and 15 weeks subsequently. During pregnancy 15 ewes were given hay and 16 dried grass (apparent dry-matter digestibilities in vitro were 51 and 69·6% respectively). All ewes were given the same dried grass during lactation and after weaning (digestibilities 75 and 73% respectively). Body fat was estimated from tritiated water space.

(2) Pregnant ewes consumed twice as much digestible dry matter from dried grass (1028 g) as from hay (502 g). Intakes of ewes with twin and single foetuses were similar.

(3) During lactation the mean daily intakes of dried grass were 2278, 2610,2612 and 2722 g dry matter respectively, for ewes that had been given dried grass in pregnancy and had single and twin lambs, and for those that had been given hay and had singles and twins. Differences between dried grass and hay were consistently significant (P < 0·01).

(4) After weaning the intakes declined rapidly but their ranking remained similar.

(5) Lamb birth weights were affected by nutrition during pregnancy, lamb growth rates within twins or singles were not influenced by maternal nutrition during pregnancy or lactation. Differences in ewe intakes during lactation were reflected in ewe body-weight changes.

(6) For all ewes, up to 64% of the variation in intake during lactation could be related to factors prevailing before and at lambing (pregnancy diet, ewe weight and fat content) and during lactation (lamb gain and ewe weight change).
A comparison of Canadian Holstein and British Friesian steers for the production of beef from an 18-month grass/cereal system
Authors: Cook K. N. , Newton Jennifer M.
Published: September 2010

The trial compared 50 purebred Canadian Holstein and 46 British Friesian steers. The cattle were reared on a grass/cereal system designed to achieve an overall target live-weight gain of 0·82 kg per day from weaning to slaughter at 18 months of age. The cattle, born i n September 1973, grazed during the summer of 1974 and were slaughtered out of yards from January to July 1975. Equal numbers of each breed were allocated at random to three slaughter weights (477, 500 and 523 kg live weight). The Meat and Livestock Commission measured and classified all carcasses. In addition, a sample was cut according to commercial specifications. There were no significant differences in slaughter age or live-weight gain between the breeds. A significant difference (P < 0·05) in killing-out percentage was found in favour of the British Friesian as was a small (4%) but highly significant difference (P < 0·001) in carcass gain.

The Canadian Holstein carcasses were considerably longer (P < 0·001) with less eye-muscle area (P < 0·001). The British Friesian carcasses contained 0·7% more saleable meat (P < 0·001) and 1% less bone (P < 0·01). There were no significant differences in fat trim. There were large differences in live appearance and carcass classifications, the British Friesians being of superior beef conformation.
A simple model of lactation curves for milk yield, food requirement and body weight
Authors: Wood P. D. P.
Published: September 2010

Simple algebraic models of milk yield, live-weight change and food requirement are developed for use in a programmable desk calculator. The unit of time used is a week and of energy a megajoule. An algebraic equation for milk production is used to define potential energy output. An expression using live-weight gain describes the demand for energy for the recovery of weight lost and the requirements of pregnancy. The use of appropriate conversion factors enables the necessary dietary input to be calculated. The model also takes account of restricted feeding by allocating dietary energy to milk production and live-weight gain in proportion to their potential demand. Ten decisions relating to milk yield, live-weight loss and live-weight gain are required by the model.
Genetic responses in the early years of selection programmes using genetic differences between generations
Authors: Hopkins I. R. , James J. W.
Published: September 2010

Recurrence relationships are used to relate breeding values of age-sex classes from different time periods. Their application to single-stage (progeny) and multi-stage (parent) selection is demonstrated. These relationships enable definition of the effect of age structure, initial genetic differences between age groups, and the extent to which allowances are made for these or later genetic differences between age groups. The expressions derived show that, given initial genetic differences between age groups, subsequent progeny means will fluctuate even under completely random selection. Using these means as a basis for measuring responses to selection, it is shown that there can be selective effects where selection is at random within parental age classes. A careful definition of the alternative programme is therefore important in interpreting results of selection experiments and in investment appraisal of selection programmes.

These models were then used to describe economic returns from parent and progeny selection programmes and from programmes in which returns are realized in more than one age group. A further extension of the model accommodates the effects of finite population size on returns through its effects on genetic variance.

By separating the (constant) within- and (fluctuating) between-group components of the selection differential within the recurrence relationships a number of computational problems are overcome.
A comparison of different predictors of the lean content of pig carcasses 2. Predictors for use in population studies and experiments
Authors: Evans D. G. , Kempster A. J.
Published: September 2010

Linear measurements and sample joint dissections were examined as predictors of carcass lean percentage using data from 1060 carcasses comprising 108 subgroups (nine genotypes × two sexes × two feeding regimes × three slaughter weights). The potential predictors were examined in terms of precision, cost and the stability of their regression equations.

Probed fat thickness 6·5 cm from the dorsal mid-line at the last rib (P2) was the individual measurement giving the most precise prediction (residual s.d. pooled within subgroups = 2·21 percentage units; r = −0·72). The square root transformation (P2½) gave stable regression slopes over levels of all four factors, though there were important differences in intercepts between genotypes, sexes and slaughter weights.

The precision of prediction from the lean percentage of sample joints was generally improved by including P2½ with each in multiple regression. Used in this way with current Meat and Livestock Commission costings, the ham joint offered the best compromise between cost and precision (pooled residual s.d. = 1·25 percentage units; R = 0·92). Regression slopes on each joint were stable for all factors except for those on the rump back and rib back joints which varied by feeding regime. Intercepts varied by genotypes for all joints except the ham, while intercept differences for feeding regimes were small or non-significant.

The results confirm the value of the ‘sub-sampling with regression’ procedure for predicting carcass composition.
The flock-mating of progestagen-synchronized ewes 3. A note on the influence of flock size upon mating behaviour and lambing performance
Authors: Bryant M. J.
Published: September 2010

Crossbred ewes in which the oestrous cycles had been synchronized by the use of progestagen-impregnated vaginal sponges were mated with Suffolk rams either as a single group of 68 ewes (G) or as four subgroups of 17 ewes (S) in 2 years. Ram:ewe ratio was 1:17 in both treatments. G rams performed more mounts and services than S rams. Non-return rate and lambing rate was better for S than G ewes, especially in Year 1, when fewer G ewes were served. Mating activity was greater in Year 2 than Year 1; prolificacy was also markedly improved.
The performance of lambs reared by ewes given protected lipids during late pregnancy and early lactation
Authors: Steele W.
Published: September 2010

1. Two groups of ewes were given a dietary supplement containing 40 g of either ‘protected’ tallow (PT) with only 3% linoleic acid or ‘protected’ safflower oil (PP) with 57% linoleic acid for 28 days prepartum and 30 days post-partum.

2. Although the birth weights of the lambs were unaffected by dietary treatment, the lambs in the PT group gained weight approximately 20% faster than those in the PP group.

3. The gross compositions of the milks of both groups of ewes were similar but the milk fat obtained from the PP group contained about twice as much linoleic acid as was found in the PT group.

4. Dietary treatments did not affect the haematocrits, red blood cell (RBC) or white blood cell numbers of the lambs. However, the haematocrits were higher at birth than at 10 days later and the RBCs were found to be less fragile at birth than at 10 days later.

5. The ratio of trienoic/tetraenoic fatty acid in the plasma lipids of the lambs was positively correlated with live-weight gain. Male lambs grew faster than females and twins faster than triplets and the trienoic/tetraenoic ratio was higher in males than females and higher in twins than in triplets.

6. These results showed that although it was possible to increase the linoleic acid content of the milk of ewes and of the blood lipids of their lambs by feeding protected safflower oil, no increase in lamb growth was obtained.
Studies of rectal temperature, respiratory rates and heat tolerance in cattle in the humid tropics
Authors: Amakiri S. F. , Funsho O. N.
Published: September 2010

The rectal temperature and respiratory rates of German Brown, Friesian, German Brown/Friesian crosses, N'Dama and German Brown/N'Dama (BN) crosses were studied with a view to establishing baseline data for cattle in the humid tropical environment of Nigeria.

Mean morning (38·62°C) and late afternoon (39·19°C) rectal temperatures for the various breeds were found to differ significantly (P<0·01). However, general breed differences as well as differences between heifers, milking cows, bulls and calves were not significant. Respiratory rates (counts/min) were also significantly higher (P<0·01) in the afternoon than in the morning and appeared related to changes in atmospheric temperature and relative humidity. Breed differences in respiratory rates were also significant, being within the range 17 to 34 in N'Dama, 24 to 43 in BNs and 29 to 51 in the German Brown and Friesian.

Heat tolerance indices were very high (89 to 91) for all the breeds studied but showed that the Friesian and German Brown were less heat tolerant than the BNs, and the N'Dama and White Fulani. The results indicate the need to consider diurnal changes in rectal temperature and respiratory rates in the use of these parameters for clinical diagnostic purposes.
Protein, fat and carbohydrates in the diets of pigs between 7 and 28 days of age
Authors: Wilson R. H. , Leibholz Jane
Published: September 2010

In two experiments, pigs were weaned at 4 to 5 days of age and offered dry diets based on milk proteins and tallow. Live-weight gains between 7 and 28 days of age were 220 g/day with feed conversion ratios of 0·80 when the optimum diets were given.

Expt 1 was a 2 × 2 × 2 factorial with eight pigs per treatment. There were two sources of carbohydrate, lactose and wheat starch, two levels of fat, 40 and 250 g/kg and two levels of crude protein, 140 and 250 g/kg of the diet. There was no significant difference in the performance of pigs when they were fed lactose or wheat starch as the source of carbohydrate. However, the feed intake of the pigs and their weight gains and apparent digestibilities of dry matter and nitrogen were lower when the diets contained 250 g fat/kg than when the diets contained 40 g fat/kg.

In Expt 2 six diets were fed to 12 pigs each. The diets contained 150, 180, 210, 240, 270 or 300 g/kg of crude protein. Weight gains and nitrogen retention showed a positive correlation (r= 0·997) with the dietary nitrogen intake but there was no statistical increase in these parameters above the 270 g crude protein/kg level. The apparent digestibilities of dry matter and nitrogen showed a similar trend. A value of 141 mg nitrogen/day per kg M0·75was estimated as the metabolic endogenous loss of nitrogen.
The effect of silage type on the performance of lactating cows and the response to, high levels of protein in the supplement
Authors: Gordon F. J.
Published: September 2010

A change-over design experiment, comprising four periods each of 4 weeks' duration, was used to evaluate three silage types each fed with two levels of protein in the supplement in a 3×2 factorial arrangement. The three silages were high digestibility unwilted (A), high digestibility wilted (B) and low digestibility unwilted (C). The supplements had crude protein contents of 152 and 240 g/kg dry matter, and were offered at a standard rate of 10 kg undried weight daily. The mean silage intakes were 9·3, 9·5 and 8·6 ±0·19 kg dry matter/day for A, B and C respectively, but protein content of the supplement had no significant effect on the intake of silage. Milk yield was significantly affected by both silage type and protein content of the supplement, with the mean yields being 23·6, 23·9 and 22·0 ± 0·49 kg/day for A, B and C respectively, and 22·4 and 24·0 ±0·40 kg/day for the medium and high protein supplements respectively. Although there was no significant interaction between silage type and protein content of the supplement, the greatest response to increased protein was obtained with B. Neither silage type nor protein content ofthe supplement affected animal live weight or milk composition (other than fat content, which was significantly affected by silage type). Blood plasma urea levels were 281 and 405 ± 28·0 mg/1 for the medium and high protein supplements respectively.

Total ration digestibility and nitrogen balances were carried out on three animals per treatment. The digestibility of dry matter, organic matter and nitrogen was significantly affected by both silage type and level of protein in the supplement. The output of nitrogen in the urine was also significantly affected by both these factors.
A note on the influence of micronization and polyethylene glycol on the nutritional value of brown sorghum for growing pigs
Authors: Savage G. P. , Smith W. C. , Briggs P. A.
Published: September 2010

Micronization followed by grinding of brown-seeded sorghum increased starch availability in vitro but had no effect on proximate composition of the grain. In diets containing 70% of sorghum in ground or micronized and ground form, apparent digestibility of dry matter and nitrogen and nitrogen retention by growing pigs were improved (2·5, 5·0 and 12·2% respectively). Addition to the diet of 0*2 g polyethylene glycol per g crude protein in the sorghum fraction produced similar effects. In the ground cereal diet inclusion of polyethylene glycol increased apparent digestibility of gross energy (3·8%) and improved metabolizable energy content by 5·5%, but i n the micronized and ground cereal diet the additive had no effect.
The effect of body condition and time of mating on the reproductive performance of Masham ewes
Authors: Newton J. E. , Betts J. E. , Wilde Renée
Published: September 2010

Masham ewes were mated at three stages of the breeding season, early (15 September to 20 October), mid (20 October to 24 November) and late (15 December to 19 January), at two different body condition scores, 4 and 2, for 3 successive years. The mean scores achieved for body condition 4 were 3·6, 3·7 and 3·9 for early, mid and late respectively and for body condition 2 were 2·4, 2·3 and 2·2. In the late lambing flock more ewes were marked by vasectomized rams and less ewes were barren than in the early and mid flocks. The ewes in higher body condition at mating had significantly more triplets and fewer singles, and a higher lambing percentage (183 versus 165). This effect of body condition on litter size distribution was significant at each time of mating, with the ewes at the late mating producing significantly fewer triplets and more singles; this difference was caused by a reduction in the performance of the body condition 4 ewes in the late group.

Young ewes in the body condition 4 group produced significantly fewer triplets and more singles than the mature ewes in the same body condition group, but at the lower body condition age had no effect on litter size distribution.
Genetic factors influencing atrophic rhinitis in the pig
Authors: Kennedy B. W. , Moxley J. E.
Published: September 2010

Data from 1447 pigs from 438 litters were used to estimate heritability, breeding and mating system differences and heterosis of atrophic rhinitis. Yorkshire, Landrace and Lacombe breeds and their crosses were represented. Rhinitis was measured by necropsic examination of the degree of degeneration of the nasal turbinates. Two traits were considered: rhinitis incidence, based on whether or not pigs showed any nasal turbinate degeneration; and rhinitis score, which ranged from zero to four, based on the percentage of nasal turbinate degeneration exhibited. Heritabilities of rhinitis incidence and score were 0·12±0·09 and 0·03±0·02, respectively. Mating system differences were significant but differences between crosses within mating system were not. Estimates of heterosis of two-breed, backcross and three-breed cross pigs over purebreds were respectively, 1·1, 3·4 and 22·1% for rhinitis incidence and 10·1, 13·2 and 28·5% for rhinitis score.
A note on the lactation curves of some high-yielding British Friesian cows
Authors: Wood P. D. P.
Published: September 2010

In the year ending September 1977, 242 British Friesian cows were recorded as having produced more than 10 000 kg in a 305-day lactation. The model y(n) = anbe−cn was fitted to the monthly test day yields of each lactation (a, b, c are constants, e the base of natural logarithms and y(n) the average daily yield in week n). The model explained 87·7% of total variation in the loge y(ri), and the mean constants were 31·8, 0·3160 and 0·0373. Seasonality of production was confined mainly to a spring peak of about 10% above an approximately constant level of production during the rest of the year. These lactations generally peaked later, were more persistent and showed less response to seasonal variation than average.
The effect of type of silage and level of concentrate supplementation offered during early lactation on total lactation performance of January/February calving cows
Authors: Steen R. W. J. , Gordon F. J.
Published: September 2010

A 3 × 2 factorial design experiment using 84 British Friesian cows was conducted to assess the effect of offering three types of grass silage and two levels of concentrate supplementation during early lactation on the total lactation performance of cows which calve during January and February. The three types of silage were early-cut wilted (ECW), early-cut unwilted (ECU) and late-cut unwilted (LCU), and the two levels of concentrate supplementation were 538 kg (LC) and 738 kg (HC) during a mean post-calving period of 71 days. The animals had a mean calving date of 29 January and were blocked according to calving date, and allocated at random to the treatments within each block on day 7 of lactation. The treatments were applied from day 7 of lactation until the animals were turned out to pasture on 18 April. Mean milk yields for the indoor period were: HC treatments 1963 (ECW), 1979 (ECU) and 1830 (LCU); LC treatments 1938 (ECW), 1942 (ECU) and 1731 (LCU) ± 41·3 kg; and for the total lactation were: HC treatments 5375 (ECW), 5438 (ECU) and 5284 (LCU); LC treatments 5509 (ECW), 5529 (ECU) and 5316 (LCU) ± 184·1 kg. There was no significant interaction between silage type and level of concentrate supplementation.

Milk composition, animal live weight and body condition were not significantly affected by either silage type or level of concentrate supplementation.
Quantitative studies of sweating rate in some cattle breeds in a humid tropical environment
Authors: Amakiri S. F. , Onwuka S. K.
Published: September 2010

The sweating rate of N'Dama cattle was found to show a significant stepwise increase from 10.00 h to 14.00 h (P ><0·01).

Among breeds, the sweating rates (mg/10 cm2 per 5 min) in White Fulani and N'Dama cattle were similar (100·8 to 118·3), but were significantly higher than for N'Dama × German Brown (74·4), German Brown (62·6) and Friesian (56·7) cattle (P<0·10).

Sweating rate was significantly higher for the neck and midside (90·0 to 93·3) than for other sites (75·1 to 80·0) (P<0·05).
The effect of trenbolone on acetate growth, blood hormones and metabolites, and nitrogen balance of beef heifers
Authors: Galbraith H.
Published: September 2010

Four animals from a group of eight Hereford × Friesian heifers weighing approximately 365 kg were implanted with 300 mg trenbolone acetate at the beginning of a 60-day trial period. Treated heifers grew more quickly (P<0·05) and converted food to liveweight gain more efficiently (P < 0·01) than untreated cdntrols. They had lower overall concentrations for serum albumin and plasma urea (P<0·01), the differences being maintained throughout the diurnal periods studied. No significant differences were recorded in the mean values for serum total protein, plasma glucose or free fatty acids. Similarly, the absence of significant differences in the mean values for serum growth hormone, insulin and prolactin suggested that these hormones did not mediate the response to trenbolone acetate. Implanted heifers had a significantly greater retention of nitrogen (P<0·01) which was mainly due to a reduction in the excretory products associated with total urinary nitrogen.
Breed variations in the shape of the lactation curve of cattle and their implications for efficiency
Authors: Wood P. D. P.
Published: September 2010

Mean daily milk yield, fat percentage and protein percentage were recorded monthly, from August 1978 to July 1979. for 579 303 British Friesian, 6 608 Shorthorn, 27 374 Ayrshire, 19 529 Jersey, and 19 760 Guernsey cattle and classified by breed, parity and stage of lactation. Parameters of the function y(n) = anb ecn were estimated for each breed/parity group for yield, fat percentage and yield, protein percentage and yield, and energy (MJ) output as milk (b and c describe the shape of the curve, a is a scalar, n the week of lactation and e the base of natural logarithms). In the mature cows of each breed (parity 4 or more), the shape constants (b, c) for milk, fat and protein production in kg respectively were:

Generally, cows of all five breeds which calved in the winter produced about 4% more milk, fat and protein than average, and those that calved in the summer produced about 4% less. After allowing for that, and removing the effect of the calving pattern, a seasonal variation in production occurred to produce a peak in June 1979 nearly 12% above average for liquid milk, in July 1979 about 4% for fat and in June 1979 about 12% for protein production (not percentage). Trough month was January 1979 for all three characters: —8%; —4% and — 9% respectively.

A consideration of the theory of metabolizable energy suggested that the peak of energy output which occurred about week 4 of lactation in all breeds and parities, expressed as a fraction of the live weight of the animal, had a critical bearing on the need to mobilize body reserves.
Fat changes in breeding sows
Authors: Whittemore C. T. , Franklin M. F. , Pearce B. S.
Published: September 2010

One hundred and eight crossbred sows from nine different commercial sources were monitored over two parities for changes in live weight and fatness. All sows were given a common nutritional regime. Thirty sows were slaughtered and physically dissected. After weaning the second litter, mean carcass measurements ( ± s.d.) were: live weight, 139±9·5kg; lean mass, 26·6 ± 2·8kg; subcutaneous fat mass, 4·l ± l·7kg; ultrasonic P2 backfat depth (USP2), 11·3±2·8mm; total dissected fat (kg) = 0·63 ± 0·073 USP2 —1·1 ±0·85(r = 0·85). Between mating (parity 1) and weaning (parity 2) sows gained 22kg live weight and lost 6·8mm backfat. There were significant differences between sources with respect to fatness, despite standardized feeding. It is suggested that for breeding pigs such as these, starting their reproductive life with limited fat reserves (16·4 ± 3·0mm USP2 at 92 ± 6kg live weight), a conventional fat-exploiting feeding regime is unlikely to be appropriate.
A note on the efficacy of continuous v. limited boar exposure on puberty attainment in the gilt
Authors: Kirkwood R. N. , Hughes P. E.
Published: September 2010

Thirty Large White × (Landrace × Large White) gilts were allocated to one of three treatments such that one gilt from each of 10 litters was on each treatment. The treatments were: (i) continuous boar exposure (CB); (ii) 30-min daily boar exposure (DB); and (iii) control, which had no boar exposure (NB). The experiment started at a gilt age of 165 days, and continued until either puberty was detected or a cut-off age of 250 days was reached.

The results indicate no significant difference in age at puberty between the CB and DB groups (194·6 v. 198·7 days), although both were significantly younger at puberty than the NB group (232·1 days, P<0·01). A possible ‘boar age’ effect is discussed.
A note on the fatty acid composition of backfat from boars in comparison with gilts and barrows
Authors: Smithard R. R. , Smith W. C. , Ellis M.
Published: September 2010

Backfat from each of 25 littermate boars, barrows and gilts, which were crosses of the Large White and British Landrace breeds slaughtered at approximately 90 kg live weight, was analysed for fatty acid composition. Fat from boars had a significantly higher proportion of total unsaturated fatty acids (61·6%) compared with barrows (60·2%), This sex difference was due to a lower palmitic acid (16:0) content and higher linoleic (18:2) and linolenic (18:3) fatty acid levels in backfat of boars. Gilts were intermediate to boars and barrows in the degree of unsaturation of backfat.
The incorporation of alkali-treated straw in fattening rations for male cattle
Authors: Holzer Z. , Levy D. , Folman Y.
Published: September 2010

The fattening process of male cattle was divided into three weight stages: 150 to 250kg, 250 to 400kg, 400 to 490kg. Seventy animals were fed either a control (C) diet containing 10·3 MJ/kg metabolizable energy and some hay, or an experimental (E) diet containing 8 4 MJ/kg, in which NaOH-treated wheat straw (450g/kg) and long straw (50 g/kg) were incorporated.

The diets were given during the three weight stages to five treatment groups as follows: 1. C-C-C. 2. E-E-E. 3. C-E-E, 4. C-E-C, and 5. E-E-C. The average daily gain and metabolizable energy conversion ratios were: 1344, 980, 1127, 1145, 1094g/day and 71·4, 90·6, 77·3, 73·7, 79·8 MJ/kg live weight, respectively. The saving of concentrates plus hay in groups 2 to 5 compared with group 1 was 1·33, 1·65, 0·84 and 0·91 kg/kg live weight respectively, and the concentrates plus hay by straw replacement ratio was 3·80, 2·12, 2·00 and 3·06, respectively. Dressing percentage and percentage of fat in the large depots of the animals in groups 1 to 5 were 57·2, 58·7, 58·3, 57·8, 57·9 and 3·88, 2·28, 2·52, 3·42, 2·81, respectively. The results suggest that it is not economical to feed the E-diet to animals before they reach a weight of 250 kg, and that termination of the feeding process by a highly concentrated diet is not advantageous.
The chemical composition of the intensively fed lamb
Authors: Theriez M. , Tissier M. , Robelin J.
Published: September 2010

Intact male lambs from Limousin and Charmoise breeds, or crossbreds from F1 (Romanov × Limousin) ewes sired by Berrichon rams, were early weaned, intensively fed, and slaughtered between 20 and 40 kg of empty body weight. The whole carcass was chemically analyzed, and the results expressed on a shorn, empty body-weight basis.

Some between breed differences in the weight of fat and gross energy content were found: fat contents ranged from 179 to 212g/kg at 30 kg of empty body weight. The corresponding range for energy was 10·8 to 11·8MJ/kg of empty body weight. Differences between protein and ash contents were limited, from 154 to 165g/kg empty body weight, and from 31 to 33g/kg empty body weight respectively.

At the same empty body weight Charmois lambs (a small sized breed) contained more fat, less water and less protein than the crossbreds. Values obtained on the Limousin lambs were intermediate.

There was no evidence of diet or growth rate effect on chemical composition when compared with published data obtained from more conventionally fed lambs.
The influence of the presence of the female on the sexual behaviour and plasma testosterone levels of the mature male pig
Authors: Hemsworth P. H. , Winfield C. G. , Chamley W. A.
Published: September 2010

Twenty-seven mature boars were housed in individual pens for 9 weeks under one of the following social conditions: isolated from female pigs; near sexually non-receptive female pigs; and near sexually receptive female pigs. The sexual behaviour of the boars during the 9-week treatment period was observed weekly in standard 15- min tests. The sum of the individual courting behaviour activities and the total time spent ejaculating were significantly greater for the boars housed near either sexually receptive or sexually non-receptive females than for those boars isolated from female pigs (P<0·01 and P<0·05, respectively). Although the boars housed near sexually receptive and sexually non-receptive females achieved 43 and 38% more copulations, respectively, than those isolated from females, the difference was significant only for the latter comparison (P<005). There was no consistent difference in testosterone concentration over a 12-h period between boars housed near sexually-receptive females and those isolated from females.
Effect of supplementary feeding and herbage mass on the intake and performance of grazing ewes in early lactation
Authors: Milne J. A. , Maxwell T. J. , Souter W.
Published: September 2010

1. Two experiments were conducted to examine the effects of a cereal-based supplement and herbage mass on the intake and performance by Border Leicester × Scottish Blackface ewes nursing twin lambs in early lactation.

2. In one experiment 16 ewes, individually penned, were given one of four amounts of supplement (0, 320, 640 and 960 g organic matter per ewe per day) and offered ad libitum freshly-cut perennial ryegrass herbage (organic-matter digestibility 82%). Intake of herbage and total organic matter digestibility declined linearly with increasing intake of supplement (0·84 g organic matter of herbage per g organic matter of supplement and 0·50 percentage units per 100 g organic matter of supplement respectively).

3. In the second experiment three amounts of supplement (0, 480 and 960 g organic matter per ewe per day) were offered individually to groups of seven ewes grazing a perennial ryegrass sward of high digestibility, maintained at herbage masses of either 500 or 750 kg organic matter per ha. A further group of seven unsupplemented ewes were grazed on the same sward maintained at 1500 kg organic matter per ha. Intakes of herbage and digestible organic matter by ewes, and lamb live-weight gain, were all significantly greater and ewe live-weight loss significantly less at herbage masses of 750 and 1500 tha n at 500 kg organic matter per ha (P <0·05). The mean decline in herbage intake was 0·93g organic matter per g organic matter supplement consumed. Amount of supplement had no significant effect on lamb live-weight gain at either weight of herbage nor on ewe live-weight loss at the 750 kg organic matter per ha herbage mass. At 500 kg organic matter per ha herbage mass, intake of digestible organic matter was significantly greater and ewe live-weight loss was significantly less for 960 than for 0 and 480 g organic matter per day amounts of supplement (P <0·05).
A note on the use of whole, moist barley treated with ammonia as a feed supplement for sheep
Authors: Laksesvela B.
Published: September 2010

Whole, moist barley treated with ammonia (A), whole, untreated barley (WU) and ground barley (G) were fed with hay and a little high protein, mixed concentrate. Digestibilities of dry matter, organic matter and crude fibre, assessed with young adult female sheep, were highest in diet A and lowest in diet G. The digestibilities of dry matter and crude fibre were also higher in diet WU than in diet G. Digestibility coefficients for dry matter and organic matter in barley, calculated by difference, appeared higher in A and in WU than in G. Young female sheep fed on the above diets from the age of 7 to 11 months ate more hay and gained more weight on A than on G; again diet WU was intermediate. Differences also occurred between the three groups as regards volatile fatty acids in the rumen fluid. Sheep on A or WU had a higher pH in the rumen fluid than those on G. Finally, sheep on A gave birth to more offspring than those on WU or G. All these differences were significant.
The effect of the method of presentation of a concentrated solution containing urea, minerals, trace elements and vitamins on the voluntary intake of oat straw by beef cattle
Authors: Bass Jean M. , Fishwick G. , Parkins J. J.
Published: September 2010

Sixteen Hereford-cross cattle (mean live weight 263 kg) in groups of four were individually given 1·5 kg cubed barley per day with ad libitum access to oat straw. In a 4 × 4 Latin square design (21-day feeding periods) they were additionally given either no supplement (diet A) or 100g/day of a fully soluble liquid supplement containing urea (equivalent to 1090 g crude protein per kg), calcium, phosphorus, sodium, trace elements and vitamins, presented either in the cubed barley (diet B), in the drinking water (diet C) or in a molasses lick (3 parts molasses:2 parts liquid supplement:1 part water) (diet D). Each method of supplementation significantly increased the mean voluntary straw dry-matter intake from approximately 2·9 to approximately 3·25 kg. Mean blood urea concentrations were significantly increased from approximately 1·0 to approximately 1·9 mmol/1 by all three treatments. The coefficients of variation for the individual blood-urea values of the cattle when given each of the three treatments were very comparable, indicating that there was a reasonable individual uniformity of intake of liquid supplement irrespective of method of presentation.
Results of pig progeny testing in Great Britain
Authors: Smith Charles
Published: September 2010

From 1958 to 1962 over 800 boars and 3,000 sows were progeny tested at the national pig progeny testing stations in Great Britain. Their test results for four traits (daily gain, feed efficiency, average backfat and carcass length) have been used to study the amount and effectiveness of selection and to review the use of the test facilities and their effect on pig improvement.

The amount of selection on test results was studied by measuring the difference in performance of animals with sons subsequently tested and all contemporary tested animals. The selection differentials found were from 0·05 to 0·30 standard deviation units for the four traits studied which represents a rather mild degree of selection. Thus selection could have had only a small effect in improving the testing population. In fact sons of tested animals showed little advantage over their contemporaries in test performance. Parent-offspring regressions were calculated and these, in agreement with theoretical estimates, indicated that selection would be effective and would lead to genetic changes in any of the four traits studied. Genetic correlations among the four traits were also calculated and indicated genetic compatability in improving the four traits concurrently.

Two proposals intended to increase the impact of testing on pig improvement are put forward. These are (1) to restrict the testing facilities to a small nucleus set of breeders who could concentrate on testing and selection and (2) to replace the progeny testing by performance testing which would allow a more intense selection and a greater rate of improvement for the same testing facilities.
The effects of different amounts of liquid skim-milk on pork pigs with particular reference to carcass quality
Authors: Barber R. S. , Braude R. , Hosking Zena D. , Mitchell K. G.
Published: September 2010

1. Seventy-two individually fed pigs on six treatments were used to determine the effects on performance and in particular on carcass quality of (a) giving quantities of liquid skim-milk (preserved with formalin) in excess of those normally recommended; (b) replacing meal by skim-milk in the ration on a calculated dry-matter basis (1 gal. skim-milk equivalent to 1 · 1 lb. meal) as compared with a calculated energy basis (1 gal. skim-milk equivalent to 1 · 3 lb. meal) and (c) giving skim-milk for only a part of the growing period instead of throughout. The experimental period continued from 9–10 weeks of age until slaughter at an average live-weight of 135 lb.

2. Extensive carcass measurements were taken and in addition assessment of the carcasses was made by a representative of the County Quality Pork Association and by an expert pork butcher.

3. Carcasses from pigs given an all-meal diet were comparable in all respects with those from pigs given skim-milk throughout up to a maximum of either 5¼ or 10½ pints per pig per day.

4. Carcasses from pigs given the highest level of skim-milk (maximum of 15¾ pints per pig per day) were superior in many respects to those on any of the other treatments, but the possibility that this was due to their slower rate of growth rather than to the high level of milk per se, is discussed.

5. Pigs given skim-milk as replacement of part of their meal allowance on a calculated dry matter basis grew significantly faster than those in which the replacement was made on a calculated energy basis or than those given an all-meal diet. The importance is stressed of ensuring that in assessing the value of skim-milk for pigs the caloric value of the rations being compared is similar. The need for experiments based on actual determinations of the caloric value of the rations used is also emphasised.

6. While the performance of pigs given skim-milk up to 75 lb. live-weight only was similar to that of pigs given skim-milk throughout, evidence was obtained that the quality of their carcasses was slightly inferior.

7. There was some suggestion that as the level of skim-milk in the diet increased an eye muscle of a rather paler colour was produced.
A note on the heritability of muscle colour in pigs
Authors: Pease A. H. R. , Smith C.
Published: September 2010

Muscle colour has been recorded on pigs tested at the national pig progeny testing stations in Great Britain since 1958. From September 1960 a muscle colour score on a scale of 1 to 7 points has been given by comparing the muscle colour with a series of seven coloured discs of increasing colour intensity. These discs were prepared specifically (by Tintometer Ltd. Of Great Britain) to score muscle colour in pigs. The higher the colour score the more desirable the colour was adjudged to be by the testing station personnel. However, scores of 6 and 7 were very infrequent and no assessment of their desirability was made. Carcasses were cut at the last rib on the day after slaughter at about 200 lb. live-weight and muscle colour was scored on the cut surface of the longissimus dorsi muscle (eye muscle).
Intensive beef production 6. A note on the nutritive value of high moisture barley stored anaerobically
Authors: Preston T. R. , Bowers H. B. , MacLeod N. A. , Phillip Euphemia B.
Published: September 2010

The use of barley for intensive beef production, as described by Preston, Aitken, Whitelaw, Macdearmid, MacLeod and Philip (1963) is now a well established practice, but one of the hazards of this feeding system is bloat. There is evidence that the risk of this condition is accentuated if the barley husk is broken down too finely as happens if the grain is ground (Preston, Macdearmid and MacLeod, 1963; Preston, 1964). It was therefore recommended that barley should be processed in a roller mill and that the moisture content should be at least 16% (Preston, 1963), for if the grain is drier than this it is difficult to prevent excessive shattering and destruction of the husk. Suitable containers, which can be sealed in order to ensure anaerobic conditions and so overcome the problem of storing damp grain (greater than 16% moisture) have additional advantages at harvest since they can be filled quickly and easily. The purpose of this experiment was to evaluate the nutritive value of barley stored under these conditions.
A note on the effect of giving milk substitute only once a day to early-weaned calves
Authors: Burt A. W. A.
Published: September 2010

Early weaning is now a well recognized and widely practised system of calf rearing which saves considerable labour compared with the former practice of giving liquid milk or milk substitutes in buckets twice daily to the age of 12 weeks.

One of the practical difficulties of bucket feeding calves twice daily is that the feeding times need to be close to the beginning and end of the stockman's working day to maintain reasonable intervals between intakes of liquid. Each feed must be followed by further time spent washing utensils. The labour demand for this can often conflict with that for milking and feeding other stock. It seemed possible that the whole of the liquid milk substitute intake of calves destined for early weaning might be provided in one feed daily with considerable saving of labour and increase in convenience.
A note on the differences between geographical areas in the gestation length and birth weight of British Friesian calves
Authors: O'Connor L. K. , Wood P. D. P. , Smith G. F.
Published: September 2010

The Milk Marketing Board's 23 artificial insemination (AI) centres which provide service in much of England and Wales are grouped into five geographical areas (Figure 1). Analyses of trials on commercial farms to study the effects of crossing Charolais bulls with dairy cows (Edwards et al. 1966), revealed significant differences between these areas in both gestation length and birth weight of crossbred calves. However, the Charolais bulls used in the trials were divided into five teams, each of three bulls, and each team was used only in a single area. Consequently, bull teams and areas were confounded. The purpose of the experiment reported here was to estimate the differences between areas in gestation length and birth weight independent of sire.
Prediction of eye-muscle area from introscope measurements on carcasses of pigs of bacon weight
Authors: Marshall Janet E. , Watson J. H. , Slattery A.
Published: September 2010

Carcasses of 156 pigs (78 gilts, 78 barrows) slaughtered at 200 lb live weight, were probed by introscope at six positions in line with the last rib. Backfat was measured directly and muscle depth was obtained as the difference between total probed depth from skin to rib and backfat depth. The various measurements were used to predict eye-muscle area measured on the exposed cross-section of the longissimus dorsi cut at the level of the last rib.

Depth of muscle at 7·5 cm and depth of fat at 10 cm were the best predictive measurements for both barrows and gilts, although muscle at 4·5 cm in gilts and at 10 cm in barrows were of equivalent value to muscle at 7·5 cm. The correlation between observed and predicted values of eye-muscle area was 0·8. The accuracy of these predictions compared favourably with those of carcass lean percentage from maximum depth of backfat at shoulder, minimum depth of fat at loin and fat depth at ‘C’.
Selection for carcass length in Large White pigs
Authors: Duckworth J. E. , Holmes W.
Published: September 2010

A sib selection programme for length of carcass was carried out for five
generations within a closed herd of Large White pigs. A generation interval
of one year was obtained.

Litter production was good throughout the project and the numbers of pigs born and reared in the final generation were 11·2 and 10·3 respectively.

Overall response to selection was predicted with reasonable success. The increase in length was associated with an increase in number of vertebrae.

Heritability for length of carcass computed from the pooled components of variance was 0·53 ± 0·12. Realized heritability was 0·5 ± 0·1. No control strain was maintained.

Correlated traits moved in the expected directions and responses were beneficial for traits such as backfat measurements and chest depth, but unfavourable for belly thickness and ham conformation. Carcass acceptability was not good initially and this deteriorated during the project. The difficulties involved in maintaining selection pressure and herd size are discussed. Abnormalities and lameness were recorded and did not increase systematically over the experiment.

It is suggested that the specific relationships between ‘conformation’, carcass value and viability require further investigation with particular reference to length of leg and length of carcass.
The voluntary intake of acetate by dairy cows given ammonium salts of short-chain fatty acids in their drinking water
Authors: Jackson P. , Hodgson J. , Rook J. A. F.
Published: September 2010

A solution of ammonium salts of a mixture of short-chain fatty acids (mainly acetic acid) was added to the sole source of drinking water of 10 lactating Jersey cows. There was considerable variation in the concentration of salts tolerated without depression in water intake. Some animals refused solution offered at a concentration of 0·5% (w/w) whereas one animal accepted solution at a concentration of 8% (w/w) and had a mean daily intake of salts equivalent to 836 g acetic acid.

2. Adjustment of the pH of the drinking solution to 6·5–7·5 increased the tolerance to the salts solution of animals which showed a low tolerance to the unadjusted solution. A mean daily intake equivalent to 480 g acetic acid was achieved without a significant depression of water intake. Replacement of 50 % of the ammonium ions by calcium increased the intake of salts by some cows but two out of eight refused the solution at a concentration of 0·5% (w/w).

3. The addition of saccharine, vanilla or aniseed to a solution of the ammonium salts gave little or no improvement in acetate intake but sodium cyclamate, ethyl acetate or molasses reduced the variability between animals in their tolerance to the solution and increased the mean intake of salts. With an addition of molasses, which gave the most marked response, there was a mean daily intake of salts equivalent to 495±26 g acetic acid.
Dry-matter intake and live-weight gain of cattle and sheep offered different grass varieties with and without clover
Authors: Miles D. G. , Walters R. J. K. , Evans E. M.
Published: September 2010

A series of animal feeding trials was designed to determine differences between grasses in dry-matter intake and animal live-weight gain, with a view to indicating better selection criteria for improving the feeding value of herbage.

Wide differences were demonstrated in feed intake and live-weight gain between single-variety grass feeds at similar levels of digestibility.

S.37 cocksfoot gave consistently good and S.51 timothy, consistently poor responses.

Supplementation of grass feeds with red clover frequently resulted in marked improvement in feed intake and animal performance.