bluuebunny/crossref_metadata_2025 huggingface dataset:
Pre- and postnatal study of the carcass growth of sheep 3. Growth of dissectable and chemical components of muscle, and changes in the muscle: bone ratio
Authors: Broad T. E. , Davies A. S.
Published: September 2010

The half carcasses of 39 pre- and postnatal Romney sheep were dissected into anatomical units of bone and, where possible, into 32 muscle units which comprised nine functional groups. The growth of wet weight of the total bone and of the muscle groups (and their chemical components, which included deoxyribonucleic acid, protein, and total lipid) was compared with the growth of the carcass using allometric analysis.

Although bone grew faster prenatally than postnatally relative to carcass weight, the growth of total muscle and of all the muscle groups and their chemical components occurred at a constant, linear rate throughout the growth period studied.

The muscle: bone ratio decreased during prenatal growth, reached a minimum at around parturition and then increased postnatally.

The abdominal, m. longissimus and thigh muscle groups grew faster than total side muscle, relative to carcass weight.

Protein, and especially triglyceride, grew at relative rates which exceeded that of muscle wet weight.

The amount and proportion of intramuscular triglyceride, and the weights of the muscle groups in sheep at three different stages of growth, were predicted from allometric equations. The content of triglyceride was greatest in the cutaneous and neck muscle groups. As a proportion of total muscle, the thigh, m. longissimus and abdominal groups increased as carcass weight increased from 1 kg to 15 kg.
An evaluation of three ultrasonic machines for predicting the body composition of live pigs of the same breed, sex and live weight
Authors: Alliston J. C. , Kempster A. J. , Owen M. G. , Ellis M.
Published: September 2010

Measurements of the m. longissimus and overlying fat at the last rib were taken on 39 live entire male pigs using three ultrasonic machines of differing complexity: Sonatest (simple A-mode machine), Scanogram (modified linear scanner) and Danscanner (‘real time’ scanner). Each machine had a different operator and interpreter. The pigs were from two lines of Large White, one selected for efficiency of lean-tissue gain (20 pigs) and the other a genetic control line (19 pigs). They were measured in the week prior to slaughter at approximately 90 kg live weight (91·4 (s.e. 4·4) kg).

The analysis was pooled within line and the precision of carcass lean prediction at constant live weight examined for the three machines. Standard deviation of lean in carcass at equal live weight was 16·2 g/kg.

A single fat thickness measurement taken by the Sonatest gave the most precise prediction (residual s.d. = 12·9 g/kg). Marginally poorer relationships were recorded for a similar measurement taken by the Scanogram (13·5 g/kg) and Danscanner (13·3 g/kg). Precision was not improved from the use of additional fat thickness measurements or, in the case of the scanning machines, from the addition of fat area over the m. longissimus or the area of the muscle itself. The results confirm that the Scanogram and Danscanner do not offer significant advantages over the simpler and cheaper Sonatest in the circumstances considered.
A note on the significance of boar salivary pheromones to the male-effect on puberty attainment in gilts
Authors: Booth W. D.
Published: September 2010

Eighteen Large White gilts were allocated to one of three treatments so that there were six gilts on each treatment. The treatments were (1) daily exposure to a nasal spray of boar saliva reinforced with 16-androstene steroid pheromones, (2) daily exposure to a nasal spray of saline and a mature boar for 20 min, and (3) daily exposure to a nasal spray of saline only.

The experiment began when the gilts were between 158 and 165 days of age, and was terminated when they reached 240 to 247 days of age, the gilts were slaughtered soon afterwards.

The results indicate that if salivary pheromones operate in the overall effect of the male on puberty attainment in gilts, the effect is of minor significance. Exposure to a mature boar confirmed the phenomenon of the 'male-effect' on puberty attainment in gilts.
Growth and carcass characteristics of crossbred lambs by ten sire breeds, compared at the same estimated carcass subcutaneous fat proportion
Authors: Kempster A. J. , Croston D. , Guy D. R. , Jones D. W.
Published: September 2010

An evaluation was carried out over a 5-year period in 10 commercial flocks of Scottish Blackface, Scottish Half-bred and Mule ewes to evaluate 10 sire breeds: Border Leicester, Dorset Down, Hampshire Down, He de France, North Country Cheviot, Oxford Down, Southdown, Suffolk, Texel and Wensleydale. An average of 43 sires was used per sire breed.

The analysis involved a total of 3360 lambs of which one-third had the left side dissected. Sire breeds were compared when their progeny were slaughtered at the same estimated carcass subcutaneous fat proportion (approx. 120 g/kg).

Carcass weights were related to the adult body size of the sire breeds with a range of 4 kg between Southdown and Wensleydale crosses. Crosses by the conventional meat sire breeds tended to have higher daily carcass-weight and lean-tissue gains than those by Border Leicester and Wensleydale sires. Texel and Suffolk crosses did not differ significantly in carcass weight, daily carcass-weight gain, daily lean gain or age at slaughter (P > 0·05).

Significant sire-breed × dam-breed interactions were recorded for daily carcass-weight gain and daily lean gain (P < 0·05). Dorset Down and Southdown crosses tended to grow relatively faster when from Mule dams; Texel crosses grew relatively faster when from Blackface dams.

There was relatively little difference between sire breeds in visually assessed carcass conformation; all the means were within two points on a 15-point scale. Texel crosses had a higher carcass lean proportion than other crosses: their advantage over Suffolk crosses was 22 g/kg.
A note on increasing lamb production of fat-tailed Awassi and German Mutton Merino sheep grazing in a semi-arid area
Authors: Degen A. A. , Benjamin R. W. , Eyal E.
Published: September 2010

The native fat-tailed Awassi and the imported German Mutton Merino (GMM) sheep are well adapted to semi-arid conditions (Degen, 1977; Degen and Shkolnik, 1978). This enables these sheep to graze large areas of the Negev Desert in Israel that is marginal for farming. However, under extensive conditions both these sheep breeds yield low lamb crops producing fewer than 1·0 lamb per ewe per year.
Studies on the nutrition of ruminants 4. The use of ground straw of different particle sizes for cattle from twelve weeks of age
Authors: Pickard D. W. , Swan H. , Lamming G. E.
Published: September 2010

Twenty-four Friesian calves were fed from twelve weeks of age on six diets containing 15 or 30% ground barley straw, the straw being ground through screens of and in.

From twelve weeks to seven months of age (120–250 kg) the calves had mean growth rates of 1·15 kg/day with a feed conversion ratio of 4·15: 1. From seven to eleven months of age (250–380 kg) the corresponding figures were 1·16 kg/day and 5·53: 1, and in the final fattening period of 11–14 months (380–500 kg), 0·92 kg/day and 8·19: 1.

These differences between stages of fattening were highly significant. There were no differences in performance due to the particle size of the straw or to the proportion of straw in the diet.
The incidence, repeatability and effect on dam performance of twinning in British Friesian cattle
Authors: Bowman J. C. , Hendy C. R. C.
Published: September 2010

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

Data on lactation yield and duration, butterfat percentage and calving interval showed no significant effect of twinning. However, consistent trends were noted showing that dams which calve twins have longer subsequent lactations, higher whole lactation yields and lower fat percentages than contemporary dams with single calves. The possible causes for these trends are discussed and are considered to be the lower breeding efficiency and longer calving intervals of dams of twins.
Photoperiodism in the ewe: 2. The effects of various patterns of decreasing daylength on the onset of oestrus in clun forest ewes
Authors: Ducker M. J. , Thwaites C. J. , Bowman J. C.
Published: September 2010

In six light-proofed buildings experiments were conducted with Clun Forest ewes to determine whether the date of first oestrus was affected by the absolute size of reduction in the case of an abrupt decrease in daylength and by the rate of reduction in the case of a given total decrease in daylength.

The mean number of days from the onset of the light treatments to first oestrus (the reaction interval) for ewes receiving gradual decreases in daylength of 3·5, 7·2 or 10·9 min/day from 1 July were 66·4, 53·7 or 33·6 days, respectively. The reaction interval for ewes receiving abrupt decreases in daylength of 3·75, 7·75 or 11·75 hr on 1 July were 59·5, 44·8 or 33·6 days, respectively. A control group of ewes at pasture on natural daylength had a mean reaction interval of 66·2 days.

It is concluded that the various light treatments applied significantly affected the date of onset of oestrus in Clun Forest ewes.
The effects of clipping pregnant ewes at housing and of feeding different basal roughages
Authors: Rutter W. , Laird T. R. , Broadbent P. J.
Published: September 2010

1. Forty Greyface (Border Leicester ♂ × Blackface ♀) and 40 North Country Cheviot ewes, due to lamb to a Suffolk ram in April 1969, were housed during December 1968 in eight groups of 10 ewes, the breeds being penned separately.

2. One pen of each breed received a basal diet of either hay, grass silage or arable silage with a ‘high’ level of concentrate supplementation and one pen of each breed was given hay with a ‘low’ level of concentrate supplementation. Within each pen, five of the 10 ewes were clipped at housing and the other five were clipped in the following June.

3. Voluntary intakes of the basal diets declined with advancing stage of pregnancy, particularly for those receiving grass silage. Feed had no differential effects on the performance of the ewes in terms of wool yield, body-weight change, birth weight of lamb per ewe or perinatal lamb mortality.

4. The Greyfaces clipped at housing yielded less wool than those Greyfaces clipped in the following June. Time of clipping had no influence on the wool yield of the Cheviots. Wool grades were not affected by time of clipping. Ewes clipped in December performed significantly better than ewes not clipped until June with a higher proportion of ewes producing multiple births (P<0·1), a higher total birth weight of lamb per ewe (P<0·01) and a reduced perinatal mortality of the lambs (P<0·05). The total effect of this improved performance was that the clipped ewes produced 53 ·5 % more live lambs than those ewes not clipped until the following June.
An evaluation of the micronization process for preparing cereals for the growing pig. 1. Effects on digestibility and nitrogen retention
Authors: Lawrence T. L. J.
Published: September 2010

1. In two experiments, each using three groups of six littermate castrated male pigs per group, the effects on cereal composition, apparent digestibility and nitrogen retention of micronizing barley and maize were studied.

2. The process increased the dry matter (DM) content and in vitro starch availability and decreased the nitrogen content of both cereals. When maize was flaked (rolled) subsequent to the process the ether-extract content was markedly decreased.

3. Nitrogen retention was not affected by the process but apparent digestibility of the DM, nitrogen and gross energy was improved. These effects were most marked when the process was followed by flaking, the improvements in such cases in digestible energy content over the unprocessed grain being 4·3% (P>0·05) for barley and 6·6% (P<0·05) for maize.

4. Soaking the unprocessed and micronized and flaked cereals before feeding did not significantly affect the results.
Induction of lambing every eight months in two breeds of sheep by light control with or without hormonal treatment
Authors: Vesely J. A.
Published: September 2010

Suffolk and Rambouillet female sheep (ewes) were kept in pens where daylight was gradually reduced and were treated, or not treated, with hormones to obtain four lambing cycles in 2·5 years. Oestrus in May, June and July was induced more easily (P<0·01) in Rambouillet than the Suffolk ewes. The advantage of higher conception rates in the Rambouillet ewes during anoestrus was offset by the higher prolificacy rates in the Suffolk in the other three lambing cycles. On average, each breed produced 128 lambs per 100 ewes exposed per lambing cycle. This corresponds to 5·1 lambs per ewe in four lambings, which is equivalent to 2·04 lambs per ewe per year. Under the conditions of the experiment, the addition of Syncro-Mate pessaries (20 mg fluorogestone acetate) and pregnant mare serum gonadotrophin (PMSG, 5 ml/ewe, 50 IU/ml) to the treatment of reduced daylight did not affect the ovulation or conception rates.
Relationship between the cumulative difference and best linear unbiased predictor methods of evaluating bulls
Authors: Thompson R.
Published: September 2010

The relationship between two methods of sire evaluation (Bar-Anan and Sacks's cumulative difference method (CD) and Henderson's best linear unbiased predictor method (BLUP)) is shown. This relationship suggests a modification, with more theoretical justification, to the CD method.
Reproduction in the gilt. 2. The influence of gilt age at boar introduction on the attainment of puberty
Authors: Hughes P. E. , Cole D. J. A.
Published: September 2010

Ten Landrace × (Landrace × Large White) young female pigs (gilts) were allocated to each of three growth rate treatments so that they attained 73 kg live weight at 135, 160 or 190 days of age. At 73 kg live weight the gilts were introduced to a vasectomized boar for 30 min each day, and were subsequently mated at the second oestrous period. The interval from boar introduction to puberty was 15·2 and 19·0 days respectively for gilts having first boar contact at 190 and 160 days of age, these intervals being significantly shorter (P<0·05) than the 34·3 days for the 135-day group. However, the mean ages at puberty of the 135- and 160-day groups (169·4 and 178·2 days respectively) were not significantly different but these gilts were significantly younger at puberty than the 190-day group (205·3 days). There were no significant differences between treatments for gilt live weight at puberty or first litter size.
A note on the value of dried citrus pulp and grape marc as barley replacements in calf fattening diets
Authors: Hadjipanayiotou M. , Louca A.
Published: September 2010

Two trials with 44 and 30 British Friesian male calves were conducted over a period of 48 and 30 weeks respectively, to study the value of dried citrus pulp and grape marc as substitutes for part of the barley in calf-fattening diets. In each case the diets were fortified with additional crude protein to compensate for the lower digestible crude protein contents of these substitutes.

Including dried citrus pulp at 60% of the concentrate diet had no effect on calf performance or feed intake, and provided additional protein is supplied, citrus pulp appears to compare favourably with barley as an energy source.

Inclusion of grape marc at 15 and 30% of the diet tended to reduce live-weight gain at the higher level and to reduce killing-out percentage and increase feed intake at both levels, resulting in poor feed utilization. Its value as an energy source appears to be about half that of barley.
Multibreed designs. 2. Genetic variation within and between breeds
Authors: Taylor C. S.
Published: September 2010

Optimal designs are given for estimating some of the genetic parameters needed to describe a population of breeds when testing facilities are limited and the number of breeds to be tested is potentially large. The best design for estimating the relative proportion of genetic variation within and between breeds is to have a large number of breeds, a few sires per breed, and a few offspring per sire, the total number of animals per breed being of the order of 10 to 20.
Digestibility studies with cows given whole and rolled cereal grains
Authors: Nordin M. , Campling R. C.
Published: September 2010

The susceptibility of whole and rolled cereal and legume seeds to microbial attack within the rumen of cows was examined by incubating seeds in nylon bags in the rumen for 24,48 and 72 hr. With whole, intact seeds the husked cereal grains were less susceptible than naked grains and legume seeds. Inter-varietal differences were observed with maize, oats and barley. Breaking the cereal grains before incubation considerably increased the losses of dry matter. Digestibility trials with non-lactating cows confirmed that barley, sorghum, wheat and oats were poorly digested when given whole, and considerable variation was recorded between individual cows in their ability to digest whole grains. Rolling the grains before feeding made the greatest improvement in digestibility with sorghum, wheat and barley and the least with oats.
Objectives in pig breeding
Authors: Fowler V. R. , Bichard M. , Pease A.
Published: September 2010

1. Some criticisms of the classical approach to constructing a selection index are advanced. This approach (theeconomic model) is contrasted with an alternative one (thebiological model) which is derived from the concept of the biological efficiency of production of lean tissues. The selection objective which is proposed from the biological model is the improvement of lean tissue feed conversion. The most important single means of achieving this is increasing the lean tissue growth rate.

2. The approaches were compared in three studies: (a) the effects of errors in economic and genetic parameters of the economic index; (b) phenotypic relationships between biological objectives and other measures of performance; (c) a theoretical model based on the utilization of metabolizable energy.

3. In a fixed situation the results were similar for both models, but the main advantage of the biological model is that it gives good indications of what happens, and what selection policies should be, in different situations. In addition, lean tissue feed conversion and lean tissue growth rate are closely related to concepts widely applied in biology, and their use as selection objectives should be helpful in enabling workers in many disciplines to make use of each other's knowledge.
The Belgian Piétrain as a sire of crossbred pigs slaughtered at 64 kg live weight. 1. Performance and carcass characteristics
Authors: Howard A. N. , Smith W. C.
Published: September 2010

A Piétrain boar was placed on each of six farms where the terminal sire was a Large White and the breeding females were either Large Whites or Large White × Landrace. Cooperators were requested to obtain 10 litters by each boar and record their performance to slaughter at 64 kg live weight. Farrowing rate to first service was relatively higher for sows mated with Large White boars but not significantly so. Pietrain-cross piglets were heavier at weaning (7·5%) but breed of boar did not influence other litter traits or age of progeny at slaughter. Pietrain crosses had higher carcass yields (2·4%), shorter carcasses (2·5%) and larger eye muscles in cross-section (10·6%) and in commercial evaluations relatively more were placed in the highest grade.
Effects of ewe's colostrum and various substitutes on the serum immunoglobulin concentration, gut closure process and growth rate of lambs
Authors: Al-Jawad A. B. , Lees J. L.
Published: September 2010

Ewe's colostrum, dried milk, ewe's blood, cow's blood and cow's serum, given to a total of 56 newborn lambs, had various effects on serum immunoglobulin concentrations, the gut closure process and early growth rate.

Cow's colostrum and serum proved to be good alternative sources of immunoglobulin for rearing lambs. Cow's and ewe's blood had adverse effects on immunoglobulin absorption, speeding up the closure process. This process was only slightly affected when lambs were fed immunoglobulin-free powdered milk.

Lambs survived with concentrations of serum immunoglobulin as low as 5 zinc sulphate turbidity units. Similar and satisfactory mean early growth rates were observed for lambs given ovine and bovine colostrum and bovine serum, whilst those given ovine and bovine whole blood had relatively low early weight gains. Those receiving powdered milk substitute followed by ewe colostrum at 8 hpost partumshowed intermediate rates of growth.
Derivation of economic weights from profit equations
Authors: Brascamp E. W. , Smith C. , Guy D. R.
Published: September 2010

The economic weights derived from profit equations depend on the base used for the evaluation. Thus different relative economic weights are obtained per unit of investment, per breeding female, per individual or per unit of product. This has led to uncertainty and confusion about appropriate economic weights in livestock improvement, and to apparent differences in interests between the investor, the farmer and the consumer. It is shown here that if the profit equation has a zero outcome, or the profit equation is transformed by setting its outcome to zero by considering profit as a cost of production (so called ‘normal profit’ in economics), then the relative economic weights are the same for all bases of evaluation. It is argued that this is the appropriate basis to determine economic weights.
The tolerance of grazing desert ewes and their lambs to prolonged intake of natural saline waters
Authors: Mittal J. P. , Ghosh P. K.
Published: September 2010

The effect of prolonged intake of saline well waters on the productive performance of 56 mature ewes and their lambs of the Magra and Marwari breed of the Rajasthan desert was studied for a period of 44 months. The sheep were maintained at pasture and given drinking water containing 0·3, 2·0 and 3·5 g/1 of total soluble salts. Body-weight changes during pregnancy and lactation, milk yields, greasy-fleece yields of the ewes, lamb birth weights and subsequent body-weight gains, up to weaning and post weaning, and greasy-fleece yield and pre-weaning and post-weaning survival rates of the lambs remained unaffected by the salinity levels in the waters tested.
The effects of reducing the remating interval after parturition on the reproductive performance of the commercial doe rabbit
Authors: Partridge G. G. , Allan S. J. , Findlay M. , Corrigall W.
Published: September 2010

Four groups of does (16 per group) were remated either 1, 7, 14 or 21 days after parturition over a 1-year production cycle. Doe mortality rate was independent of treatment and overall was 0·27. The remating interval after parturition had no effect on conception rate, which was high on all treatments (0·86 to 0·93). The high overall conception rate resulted in more litters being born as the parturition to remating interval decreased. Expressed on a common 365-day experimental period the number of litters per doe was 8·9, 8·5, 7·8 and 6·7 (average s.e. of difference 0·33) for treatments 1, 7, 14 and 21 respectively. Litter size was not significantly affected by treatment and consequently the number of pups born per doe per year increased as remating interval decreased: 75·0, 73·4, 67·4 and 591 respectively. Pup mortality rate at birth and subsequently was high (0·42) on all treatments and the number of pups weaned per doe per year for treatments 1, 7, 14 and 21 was 48·3, 43·5, 40·0 and 33·3 respectively. Pup birth weight, 21-day litter weight and weaning (25-day) weight were all unaffected by treatment, as was doe body-weight change.
A note on lactation curves of crossbred cows
Authors: Jenkins T. G. , Ferrell C. L.
Published: September 2010

Milk production data were collected on 8- and 9-year-old Angus × Hereford or Hereford × Angus; Charolais × Angus or Hereford; Jersey × Angus or Hereford; and Simmental × Angus or Hereford cows at days 14, 28, 56, 84, 112, 140, 168 and 196 after parturition. During the study, cows were given diets differing in quantity of brome grass (Bromus inermis) haylage. Lactation curves were estimated by the empirical equation Y(n) = n/aekn. Differences were observed among the breed crosses in 25-week lactation yield and time of peak lactation.
A note on the use of spring pea (Pisum sativum hortense) in diets for weaned pigs
Authors: Gatel F. , Fekete J. , Grosjean F.
Published: September 2010

A comparison was made of three diets given to pigs after weaning at 28 days of age: control, control + 300 g spring peas per kg or control + 300 g spring peas + 1·2 g DL-methionine per kg. The latter diet led to similar food conversion ratio and better growth rate than the control diet. It seems therefore that provided diets are properly balanced for all limiting amino acids, spring pea (Pisum sativum subsp. hortense) can be used at least up to 300 g/kg in weaned pig diets.
Factors influencing the work done by draught oxen: a study in the eastern hills of Nepal
Authors: Anne Pearson R. , Lawrence P. R. , Ghimire C.
Published: September 2010

The work done, distance travelled and body temperature of five teams of oxen ploughing land for winter crops was measured continuously over a 5-h working day. On terraces in East Nepal the cattle worked at slow speeds (about 0·3 m/s). Daily work output was variable and depended on ground and soil conditions and on the man working the team. Estimated daily energy expenditure on working days in October and November was 1·25 to 1·46 × maintenance. Differences between teams were small. No noticeable change in performance occurred over the 5-h work, with the exception of one team which usually worked erratically over the last 2 h. Only one animal showed signs of heat stress during work, when its body temperature increased by 1·8 to 2°C, otherwise body temperature varied little (< 1°C) during work.
Factors influencing the welfare and carcass and meat quality of pigs 1. The effects of stocking density in transport and the use of electric goads
Authors: Guise H. J. , Penny R. H. C.
Published: September 2010

This experiment was designed to study the effects of stocking density in transit and the use of electric goads on pig welfare and subsequent meat quality. Sixty-four pens, totalling 1400 commercial crossbred hybrid pigs, were transported from a farm to a large commercial abattoir at either high (0·3 m2per pig) or low (>0·4 m2per pig) stocking densities. The lorry drivers loaded and unloaded the pens of pigs at either end of their journey with, or without, an electric goad. Similarly, lairage men moved groups of pigs from their lairage pens to the stunning and slaughter area with, or without, goads. Consequently, eight possible treatment combinations arose from this 2 × 2 × 2 factorial experiment. About 20 h after slaughter, the fibre optic probe (FOP) value of thelongissimus dorsimuscle was recorded and carcasses were scored for the extent of skin blemish. Pigs in high stocking density groups (HSD) had lower FOP values than those on low stocking density groups (LSD) (P< 0·05) and more severe skin blemish (P< 0·001). The effect of goading in transport or in the lairage, had no significant effect on the FOP values. However, the skin blemish data showed a significant interaction between the use of goads during transport and the stocking density treatment (P< 0·05). This interaction implied that the use of goads when loading pigs at a HSD was associated with a reduction in skin blemish. Conversely, the lowest skin blemish frequency was observed in the LSD treatment group handled without the aid of goads. Pigs in the HSD groups were visibly more skin damaged and exhibited evidence of rectal prolapse which was absent in pigs transported at LSD. Lower stocking densities are to be recommended as carcass, meat quality and pig welfare are probably improved. The use of goads is associated with a higher degree of carcass damage unless pigs are to be densely packed during transport.
Feeding and management of pregnant sows on pasture
Authors: Eyles Dudley E.
Published: September 2010

1. Wessex Saddleback sows were fed 4 lb. or 2 lb. of a balanced meal per head per day during the first 13 weeks after mating with a Large White boar. All sows received 6 lb. of meal for the last 3 weeks of pregnancy, and approximately 14 lb. (4 lb. plus 1 lb. for each piglet) during lactation. From mating to weaning half the sows on each feeding treatment had access to small soil pens, and the other half to range grazing of lucerne or grass/clover swards.

2. During the first 3 months of gestation sows on soil receiving 2 lb. of meal gained 20 lb. while those on grazing gained 40 lb., equal to the gain of sows fed 4 lb. of meal.

3. Approximately 10·5 piglets were born per sow under all treatments. Piglet mortality was highest with sows which had been fed 4 lb. of meal during pregnancy and were confined in small soil pens, because this treatment produced the greatest number of over-fat sows. Mean piglet weight at 3 weeks (≏ 12 lb.) and 8 weeks (≏ 39 lb.) and total creep-fed meal consumption per piglet (≏ 30 lb.) were similar for all treatments.

4. In a preliminary trial 3½ lb. of dried grass plus ½ lb. of meal per head per day was fed to gilts during the second and third months of pregnancy without adversely affecting farrowing results.

5. From these experiments and the published work it is suggested:—

(a) Pasture alone would probably have been sufficient during the second and third months of pregnancy of the sows used in these trials.

(b) Feeding standards for pregnant sows of 250-350 lb. live-weight may be too generous, and produce ‘fat not fit’ sows at farrowing.

(c) In practice the reduction of meal feeding and the greater dependence on grazing should be applied individually to each sow according to her condition and response.
Blood group studies on cattle of Red Polish breed
Authors: Neimann-Sørensen A. , Spryszak A.
Published: September 2010

Blood samples from 262 Polish Red Cattle, 9 Danish Red Cattle and 123 cattle produced by crossing were examined for the presence of 45 erythrocyte antigenic factors.

The frequencies of most of the factors are given and estimates are made of the appropriate gene frequencies within the Polish Red breed as a whole.

Segregation of 42 B alleles was observed of which 9 have not previously been reported. The H′ factor hitherto recorded as marking an independent system is assigned to the SU system on genetical grounds and renamed S2.

It is concluded from the blood group data that the Polish Red breed has signs of a genetic relationship with Holstein-Friesian, Brown Swiss and Guernsey breeds but the relationship with the Danish Red breed is closer. The existence of the new alleles distinguish the Polish Red breed of cattle from all others investigated.
Harness for the total collection of faeces from grazing ewe and wether sheep
Authors: Arnold G. W.
Published: September 2010

Harnesses for the total collection of faeces from both ewe and wether sheep are described and field experience with them is reported.
The size of dairy heifers
Authors: Hodges John , O'Connor L. K. , Clark W. M.
Published: September 2010

1. A field investigation to estimate the mean weight and chest girth of unserved Friesian, Ayrshire and Dairy Shorthorn heifers of between 3 and 24 months of age was carried out.

2. Data from 1,620 Friesians, 725 Ayrshires and 455 Dairy Shorthorns in the North of England were obtained, with a mobile weighbridge and a. spring-loaded steel tape in the winter 1958–59.

3. It was found that on average the Friesians were heavier and had a greater chest girth than the Ayrshires and Dairy Shorthorns, which did not differ significantly.

4. These heifers were apparently reared on planes of nutrition which, judged by conventional feeding standards, may be described as ‘low’.

5. After eliminating the linear effect of age by covariance analysis, highly significant differences between herds and between sires in weight and chest girth were found.

6. The investigation demonstrated the feasibility and value of collecting field data on body size.
The effect of variations in the energy and protein status of the diet upon productive efficiency in the pig
Authors: Costain R. A. , Morgan J. T.
Published: September 2010

A feeding trial is described in which 32 individually-fed Large White pigs were used to investigate the effects of variations in the protein and energy status of the diet on growth, efficiency of food utilisation and carcass characteristics. The salient features of the finding were:

1. Over the weight interval 50–100 lb., it appeared that 1·0% was a more appropriate level of dietary lysine than one of the order of 0·75%; the former figure corresponded to a level of 5·8% of dietary protein.

2. In the ‘finishing phase’ of growth from 100–200 lb. the pig clearly tolerates wider energy : protein ratios than is the case in earlier life, with advantageous results in terms of growth performance but deleterious effects on carcass suitability.

3. An increase in dietary energy status in the ‘finishing phase’ yields growth responses only if protein level is appropriately adjusted.

4. It is suggested that Large White pigs require a level of 0·5–0·6% of dietary lysine in the ‘finishing’ period.
Specialised sire and dam lines. I. Economic evaluation of crossbreds
Authors: Moav Rom
Published: September 2010

When commercial livestock are crossbreds, profit for the total operation including cost of production of the breeding stocks, is a function of the performance of both the crossbred offspring and their parents.

Since the performance level of the offspring is determined by its parents, it means that the parents contribute to profit determination in two ways. Reproduction cost is determined directly by the parents, that is through their own phenotypes, while productive efficiency (food conversion, growth rate, etc.) and quality are determined by the parents indirectly through the genetic determination of their offspring.

In most classes of livestock the number of males in the breeding herds, relative to that of the females, is very small. Consequently, variation in reproductive capacity of the male line contributes only little to the determination of reproductive costs, and this item can be ignored. As a result, the contributions of the parental lines to profit are unequal and of different kinds. Exploitation of this difference may produce ‘profit heterosis’ even when the component traits are genetically additive.

When profit is a non-linear function of one or more component traits another deviation of profit from the arithmetic mean of the parents is created. Unlike the previous one, this heterosis deviation is scale dependent.

Profit was presented graphically, as profit contours, on the two dimensional plane created by the variables productivity and reproductivity. This was found to be a helpful aid to an understanding of the underlying relationships.
Effects of reduction of litter size on subsequent growth and reproductive performance in mice
Authors: Machin David , Page Sheila
Published: September 2010

Litters that contained at least 13 mice were reduced at birth to 12, 8, or 4; and any natural litters of these sizes were also kept. The growth of these mice and their subsequent reproductive performance when mated at 6,10 and 14 weeks of age were recorded. All their offspring were weighed at weaning (4 weeks); some were weighed also at 12 days and 6 weeks of age.

The amount of milk supplied was not fully adjusted to the size of the litters. This had lasting effects so that, even at the oldest age for mating, the mice from the small litters were noticeably the heaviest. Litter size effects extended to significant differences in fertility (numbers born) and less obviously to the numbers weaned. The mice that were mated at 14 weeks were the most fertile. There was little to distinguish the mice from natural and reduced litters of the same size.

Small differences in weights of the offspring at 12 days, 4 weeks and 6 weeks of age bore no consistent relation to these factors.
A Comparison of some suggested measures of persistency of milk yield in dairy cows
Authors: Madsen Ove
Published: September 2010

Five measures of persistency of milk yield were compared by means of apparent heritabilities and repeatabilities using 598 first lactation records from the Danish progeny testing stations and 354 records of all parities from Red Danish cows at a state experimental farm. Unbiased estimates of heritabilities could not be obtained because of common environmental effects. Results indicate that measures of persistency giving equal weight to single milk records are superior to measures giving different weight to single records.

Correlations between persistency, expressed as the absolute decrease of yield, and maximum daily yield were —0·46 to —0·52 (phenotypic) and —0·22 (genetic). Correlations between persistency and 305-day yield were —0·06 to —0·10 (phenotypic) and 0·02 (genetic).Correlations between persistency, expressed as the decrease of yield relative to level of yield in early lactation, and maximum daily yield were —0·06 to —0·13 (phenotypic) and 0·17 to 0·42 (genetic). Correlations between the measure of persistency and 305-day yield were 0·12 to 0·45 (phenotypic) and 0·45 to 0·69 (genetic).
The response of lactating sows and their litters to different dietary energy allowances. 2. Weight changes and carcass composition of sows
Authors: O'Grady J. F. , Elsley F. W. H. , MacPherson R. M. , McDonald I.
Published: September 2010

The live-weight changes of 48 sows were recorded over three reproductive cycles. All sows were given standard amounts of feed in gestation and one of four energy allowances during lactation. The daily intakes of digestible energy during lactation ranged from 12·2 to 182·2 Meal in the first, 122·9 to 192·6 Meal in the second and 132·2 to 202·2 Meal in the third lactation. Weight change in lactation responded to energy intake; sows on the lowest energy intake lost weight whilst those on the highest intake gained. At weaning of their third litters, sows on the highest energy allowance weighed 44 kg more than those on the lowest level and this was equivalent to a carcass difference of 372·3 kg at slaughter.

All the sows were slaughtered after the third litters had been weaned and the carcasses were dissected into lean, subcutaneous fat+skin, and bone. Sows from all treatments had less subcutaneous fat+skin and more muscle and bone than non-pregnant gilts killed at a mean weight of 129 kg, a weight equivalent to that of the experimental animals at their first mating.

The reduction in fat reserves was linearly correlated with dietary energy intake of the sows. Sows receiving the lowest energy intake in lactation possessed fat reserves which were estimated to be only 25% as great as in gilts comparable to those used to initiate the experiment. This reduction in body reserves has implications with regard to the long-term effects of feeding lactating sows low intakes of energy during 6-week lactations.
Theoretical aspects of a flexible model to stimulate protein and lipid growth in pigs
Authors: Whittemore C. T. , Fawcett R. H.
Published: September 2010

A model designed to simulate growth in pigs has been developed to include the following aspects of protein and energy use.

1. It is proposed that the ratio of protein accretion to protein synthesis is a function of protein mass. Synthesis rate influences the efficiency of protein use, the energy cost of protein accretion and the energy cost of maintenance. A calculated energy cost for protein synthesis of 7·3 MJ ME/kg is suggested; the calculated energy yield from deaminated protein is 11·5 MJ ME/kg.

2. Urinary losses of nitrogen are derived from estimates of protein quality by essential amino acid index, endogenous losses and the rate of protein accretion.

3. A minimum fat to protein ratio in the gain of growing pigs of 1: 1 is assumed.

4. An estimate of critical temperature which is dependent upon live weight and heat output is used to calculate energy expenditure for cold thermogenesis.
Genetic and environmental factors influencing litter size, sex ratio and gestation length in the pig
Authors: Kennedy B. W. , Moxley J. E.
Published: September 2010

Data from 675 litters were used to study the effects of type of service, number of services, parity, year, season, breed of sire, sire, type of dam (purebred or crossbred), breed of dam, dam, breed of sire × type of dam and breed of sire × breed of dam on litter size (live births), number of males, number of females, sex ratio (percentage of males) and length of gestation. Yorkshire, Landrace and Lacombe breeds and their crosses were represented. Artificial insemination significantly reduced litter size and the number of females and increased sex ratio. Parity had a significant effect on all traits except sex ratio. Lacombe-sired litters were approximately one-half pig smaller than Yorkshire- and Landrace-sired litters. Landrace-sired litters had gestations of one-third day shorter than Yorkshires. On average, crossbred dams farrowed 0·65 more pigs per litter than pure-bred dams. Litters from Yorkshire dams, however, were more than one pig larger than Landrace and Lacombes, and did not differ significantly from crossbred dams. Gestation length of Lacombe sows was 1·34 days shorter than Yorkshires. Repeatabilities of litter size, number of males, number of females, sex ratio and gestation length were 0·15, 0·08, 0·06, 0·05 and 0·32 respectively.
Chaffed or ground straw and lucerne in the diet of the early-weaned calf
Authors: Leibholz Jane , Russell C. L.
Published: September 2010

An experiment was conducted with 72 male British Friesian calves between 5 and 11 weeks of age. The major treatments were the inclusion of 0, 20 or 40% wheat straw or 20, 40 or 60% lucerne in a complete pelleted diet. The roughage was either ground or chaffed. A methane inhibitor was included in the diets given to 36 of the calves. The weight gains of the calves were greater with diets containing lucerne than with those containing wheat straw. Grinding increased the intake of wheat straw but depressed intake of lucerne. The apparent digestibility of dry matter and acid detergent fibre, which was greater for the diets containing lucerne than for the diets containing wheat straw, was reduced by grinding both roughages.

Inclusion of the methane inhibitor in the diets increased the feed intakes and weight gains of the calves given the all-concentrate diet and the diets containing wheat straw, but not those given the diets containing lucerne.
A note on the effects of dexamethasone-induced parturition on ewe behaviour and lamb survival in prolific Booroola Merino ewes
Authors: Owens J. L. , Bindon B. M. , Edey T. N. , Piper L. R.
Published: September 2010

Normal and dexamethasone-induced parturition were compared in Merino and prolific Booroola Merinos carrying crossbred foetuses. Behavioural observations were recorded for 42 single-, 27 twin- and 10 triplet-bearing ewes. After treatment on day 144 of gestation, ewes injected with dexamethasone lambed 41 h earlier than ewes injected with phosphate buffer. On the phosphate-buffer treatment, Booroola Merino ewes lambed 22 h earlier than Merino ewes. Twin- and triplet-bearing ewes which were induced to lamb had a significantly longer duration of labour than ewes bearing singles which were induced to lamb, and ewes, regardless of litter size, which lambed naturally. Induction of parturition had no significant effect on the lambs' behaviour subsequently. Lamb survival was not influenced by dexamethasone treatment but was significantly influenced by lamb birth weight, which declined as litter size increased.
Faecal output and estimated voluntary dry-matter intake of grazing beef cows, relative to their live weight and to the digestibility of the pasture
Authors: Bruckental I. , Lehrer A. R. , Weitz M. , Bernard J. , Kennit Hanna , Neumark H.
Published: September 2010

Two experiments were carried out with 12 non-pregnant, non-lactating beef cows (Simmental x Hereford cross), six in each experiment. In experiment 1, the cows were grazing stubble pasture and each cow was hand fed 750 g/day soya-bean meal. In experiment 2, the cows were grazing green pasture at the pre-blossom stage. Paraffin-coated magnesium ferrite (MF) was used as an external marker. A capsule containing 5 g marker was administered to each cow twice daily at about 08.00 and 14.00 h. At the same time the cows were also weighed and faecal grab samples (GS) were taken. Each experimental period lasted 18 days: a 10-day period for attaining steady state of the marker, followed by an 8-day period during which faecal GS were taken.

Average live weight (LW, kg) and daily faecal output (DFO, kg dry matter (DM) per day) were, respectively 364·2 and 3·39 for cows in experiment 1, and 484·4 and 4·62 in experiment 2. DFO (g): LW (kg) ratios were 9·31: 1 and 9·53: 1 in experiments 1 and 2, respectively.

In-vitro digestibilities were used for calculating the voluntary intake (kg DM per day), which was found to be 6·8 and 13·6 for cows grazing stubble and pre-blossom pastures, respectively. The relationships between LW of grazing cattle and their DFO and voluntary food intake are discussed.
Effects of rapid inbreeding and of crossing of inbred lines on the body weight growth of sheep
Authors: Wiener G. , Lee G. J. , Woolliams J. A.
Published: September 2010

Sheep of three hill breeds, Scottish Blackface, Cheviot and Welsh Mountain and the reciprocal crosses among these breeds were inbred (mostly by parent × offspring mating) for four generations to five levels with inbreeding coefficients ofO, 0·25 (I1), 0·38 (I2), 0·50 (I3) and 0·59 (I4). Inbred females were also mated to unrelated inbred males of the same breed type to produce line crosses (LC). Each type of dam (except LC and I4) was mated to produce lambs of up to three different inbreeding levels thus allowing the effects of the individual's own inbreeding to be separately assessed from the effects of maternal inbreeding. This study examined body weight at a sequence of ages from birth to 4 years of age with 2369 animals (ages up to 78 weeks old) or 1062 animals (2 to 4 years old) contributing to the analyses.

Inbreeding of the individual had a highly significant retarding effect on body weight and growth rate up to the I2 level for weights of lambs up to 24 weeks old, with a slight recovery in performance thereafter. For the later ages examined, the maximum depression was reached at the I3 stage. The partial recovery in performance at the higher levels of inbreeding for lambs less than 24 weeks of age was also noted within lines and did not therefore appear to arise only from a loss of lines as inbreeding proceeded. The effect of dam's inbreeding was to depress growth up to the I3 level and at most ages up to I4. Line-cross lambs were generally heavier (but not significantly so) than non-inbred (F2 and the pure equivalent, O2) and progeny of line-cross dams were similar in weight to those from other non-inbred (F1, or F2 and O1, or O2 dams) or slightly better. The more highly inbred the individuals the more, in general, they fell behind the weights of the corresponding non-inbreds as they grew older. Inbreeding may thus have permanently stunted the sheep.

There were no significant differences between purebred and crossbred sheep in the rate of inbreeding depression. Only at the ages of 3 and 6 weeks was there a significant difference between the three pure breeds in the changes in weight attributable to inbreeding. Up to the age of weaning (15 weeks) the changes with inbreeding of individuals could not be explained statistically in terms of dominance effects alone and non-allelic interactions may therefore also be involved. At all ages the effect of inbreeding of the dam was consistent with dominance effects alone.