bluuebunny/crossref_metadata_2025 huggingface dataset:
A note on rationing of growing pigs according to age
Authors: Braude R. , Mitchell K. G. , Pittman R. J.
Published: September 2010

In a trial involving 231 pigs grown from 20 to 90 kg live weight, three methods of adjusting the feed allowance were compared, namely according to live weight and a scale with weekly adjustments, or according to age with fixed increments of feed, adjusted either weekly or every 3 weeks. Irrespective of the frequency of feed adjustment, rationing by age gave as satisfactory results in performance and carcass quality as rationing by live weight, and reduced labour requirements by eliminating the need for regular weighing of the pigs throughout the growing period.
A note on the retention of energy and nitrogen in rabbits
Authors: Blas J. C. De , Galvez J. F.
Published: September 2010

One hundred and twenty-four young rabbits of the Giant of Spain breed (mature weight, 4 to 4·5 kg) were slaughtered in groups at birth, 10, 20, 30, 40, 50 and 60 days of age.

Energy retention over the six 10-day periods was 10·7, 26·5, 39·0, 48·9, 72·6 and 57·3 kcal/day, energy content per unit of weight increase was 5·18, 5·52, 5·52, 5·47, 5·80 and 5·89 kcal/g, and deposition of protein (N×6×25) was 1×45, 3×09, 4×28, 5×56, 7×31 and 5×44 g/day. The regression of the energy content of the empty body (kcal) on empty-body weight (g) was:

Y = 1×734 X – 88·536

with a coefficient of regression of 0·97.
Development of a synthetic pig sire line by election with immigration 2. Immigration
Authors: Webb A. J.
Published: September 2010

A synthetic sire line has been developed over 11 generations by a process of selection accompanied by immigration. In each generation prospective immigrants of any breed were mated to native pigs already i n the Sire Line, and, ignoring breed, their progeny were given the same opportunity of being selected as the progeny from matings involving natives alone. This method of immigration is shown to be biased as a result of (a) heterosis in crosses of immigrants with natives, and (b) treating natives and immigrants as if they were members of the same population. When affected by both sources of bias, the breeding values of inferior immigrant progeny may be seriously overestimated with the result that inferior genes may enter the native population and hold back genetic progress. Methods of removing the bias and alternative systems of immigration are discussed.
Design and analysis of mixed grazing experiments
Authors: Connolly J. , Nolan T.
Published: September 2010

New methods of design and analysis for mixed grazing experiments are proposed and compared with previously reported designs. In general, with previous designs the effects of mixed grazing per se were confounded with other factors. The concepts of equality of grazing pressure and of livestock equivalents are examined and criticized when used as starting points for mixed grazing experiments. Two year's results of a mixed grazing experiment with cattle and sheep are analysed and provide evidence that mixed grazing is beneficial to both species in terms of production per animal. A simple economic analysis shows how the price ratio between the value per unit weight gain of the two species can be used to decide on the area of financial benefit from mixed- as opposed to single-species enterprises.
An intensive system of beef production from maize silage
Authors: Wilkinson J. M. , Penning Ines M.
Published: September 2010

Thirty-six British Friesian entire male calves were reared from 100 kg live weight (LW) to slaughter at 450 kg LW. They were offered maize silage ad libitum plus supplements of minerals and a protein concentrate or urea in three treatment diets: protein concentrate (P), urea (U) and (P/U) in which protein and urea each provided 50% of the supplementary N up to 200 kg LW followed by urea alone. Levels of N × 6·25 in the diet dry matter (DM) were 16% from 100 to 200 kg LW, 14% from 200 kg to 300 kg, and 12% thereafter. Barley was given to all the cattle over 12 mo of age at 1% of LW daily.

Live-weight gain in the 280-day period prior to the introduction of barley averaged 899, 684 and 580 (±31·0) g/day for P, P/U and U, respectively, and was greater for P than for the other two treatments (P<0·05). After the introduction of barley, gains were similar between treatments, averaging 1275, 1333 and 1270 (±43·2) g/day, resulting in mean ages at slaughter of 15, 16·5 and 17 mo for P, P/U and U, respectively.

Substitution of protein concentrate by urea was reflected in a reduced content of metabolizable energy (ME) in the diet and a reduced intake of DM and ME in period 1. Although the contents of ME in the diets were similar in period 2, when barley was given to the cattle, there was little evidence of compensatory growth in treatment P/U and U compared with treatment P. Live-weight gains predicted from ME intake showed good agreement with actual gains. However, reduced intakes and gains by treatments P/U and U compared with treatment P meant that the target weight and age at slaughter of 450 kg and 15 mo of age was met only by treatment P. For the complete system the cattle consumed an average of 2·3 t DM per head of which maize silage DM comprised 78%. Efficiency of feed use averaged 15·5 kg live-weight gain per 100 kg total DM eaten.
Milk production from diets of silage and dried forage. 2. Effect of ensiling ryegrass cut at two levels of digestibility and given ad libitum with supplements of dried grass pellets
Authors: Tayler J. C. , Aston K.
Published: September 2010

1. Young adult and adult British Friesian female cattle (heifers and cows) which were lactating were individually fed ad libitum on ryegrass silage of high (HS) or low (LS) digestibility with one of two levels of a supplement of pellets of dried grass (H or L) in a 2 × 2 factorial experiment with three heifer and seven cow replicates.

2. The percentages of digestible organic matters in the dry matter (DM) in vitro were respectively 64·4, 57·5 and 69·0 for forages HS, LS and and the dried grass. The HS crop, however, was significantly lower in DM content, and after ensiling with formic acid additive had a higher lactic and total acid content than the LS crop.

3. The dry-matter intake of the less acid silage LS was greater than that of HS (P<0·05) although the dry-matter digestibility of the LS diets was on average 6 units lower than the HS diets. The intakes of digestible dry matter (DDM) and digestible organic matter were greater (P<0·05) in mid lactation when HS was fed. DM and DDM intakes were significantly increased by the higher level of feeding of the dried grass supplement.

4. The yield, composition and energy content of milk did not differ between silages but the yield and protein content of the milk increased significantly at the higher level of supplement feeding. The milk yields were respectively 19·35, 17·54, 19·49 and 17·97 ± 0·505 kg/head per day for treatments HSH, HSL, LSH and LSL on these all-grass diets over lactation weeks 4 to 20. Live-weight loss was greater (P<0·01) on the LS diets. Blood composition was normal and did not differ markedly between treatments.
Fat distribution in steer carcasses of different breeds and crosses. 2. Distribution between joints
Authors: Kempster A. J. , Avis P. R. D. , Smith R. J.
Published: September 2010

Dissection data for 643 steer carcasses of 15 breed-type × feeding system groups were used to examine the distribution of intermuscular fat (IF) and subcutaneous fat (SF) depots between standardized commercial joints.

The increase in weight of IF and SF in each joint relative to the corresponding depot weight in the side was examined using the allometric equation. Pooled within-group growth coefficients for both IF and SF were lowest in the distal limb joints increasing inwards to the joints of the rib and loin regions. They were highest for the thin flank joint.

Group means for weight of IF and SF in each joint were adjusted to equal total IF and SF weight respectively using the pooled growth coefficients. Statistically significant but relatively unimportant differences were recorded between groups in the adjusted means for all joints tested. The largest differences occurred for the top piece and were 0·39 and 0·40 kg (in one side) for IF and SF respectively. The stability of regression equations between groups for predicting the percentages of IF and SF in the side from the respective percentage in each joint was also examined. Joints which gave the least precise predictions of IF (shin and leg) and SF (shin, leg and clod and sticking) had the most unstable prediction equations. The equations for the other joints differed little between groups.
Correlation between 17-OHCS levels influenced by heat stress and some basic carcass value indices in pigs
Authors: Jedlicka J. , Mojto J. , Sidor V.
Published: September 2010

Seventy-six pigs provided with indwelling venous catheters were exposed for 40 min to a temperature of 40°C and 100% relative humidity. Plasma 17-OHCS levels were determined during the period of stress and up to 24 hr thereafter. The results obtained were assessed in relation to backfat thickness, and eye-muscle area and appearance (Göfö value) in groups of 10 animals showing maximum and minimum values for these parameters. In all the animals the heat and humidity stress brought about an increase in the plasma levels of 17-OHCS. Significant differences were more often found in the induced 17-OHCS levels in those animals which appeared to be leaner on the basis of backfat thickness and eye-muscle area and produced poorer quality meat than in those with less lean of better quality. These results support the notion that there is increased activity of the adrenals of leaner types of pig which produce meat of poor quality.
Poultry litter for intensive beef production
Authors: Tagari H. , Levy D. , Holzer Z. , Ilan D.
Published: September 2010

The nutritional value of a pelleted fattening concentrate mixture, in which heat-sterilized poultry litter (PL) was included at rates of 0, 15, 25 and 35%, was studied. A digestion and nitrogen balance trial was carried out with rams, and a feeding trial was carried out with intact male cattle from the age of 8 mo to slaughter at 14 mo.

Digestibility of crude protein was related inversely to PL content of the diet. This decrease in digestibility was not accompanied by a decrease in the quality of the protein digested.

Gross and digestible energy contents of the diets were related inversely to their PL content. There were no significant differences in blood urea concentration. A concentrate mixture containing 1% urea but otherwise similar to the control, was included in the feeding trial.

There were no significant differences in rate of live-weight or carcass gain between treatments. The differences in degree of fatness of the carcasses tended to be related inversely to PL% in the diet, but they were small and reached significance only with the extreme treatments. Feed intake on PL-containing diets was higher than on the control diet, but feed conversion efficiency was impaired when the proportion of PL exceeded 25%. No significant correlations were found between total volatile fatty acids in rumen liquor and daily live-weight gain.
The Belgian Piétrain as a sire of crossbred pigs slaughtered at 64 kg live weight. 2. Butcher and consumer reactions to meat from the crosses
Authors: Howard A. N. , Smith W. C. , Lesser D. , Carpenter E. M.
Published: September 2010

Carcasses of Piétrain-cross pigs slaughtered at 64 kg live weight and purchased by retail butchers were accompanied by questionnaires aimed at obtaining an appraisal of them relative to the butchers' normal purchase. Consumer reaction to loin chops from Pietrain crosses and contemporaries sired by the Large White was determined by panel—, household- and shop-testing respectively. Retail butchers showed a strong preference for Pietrain-cross carcasses on lean content but not shape and few considered that the muscle tissue had defects. In panel— and household tests participants showed a strong preference for Pietrain-cross chops on their appearance but broad equality for the two types of chops on organoleptic properties. In shop tests a preference was shown for Piétrain-cross chops over Large Whitecross chops and those normally stocked by the shop.
A note on the effect of autumn shearing on performance of fattening lambs
Authors: Salman A. D. , Owen E.
Published: September 2010

Forty-eight castrate male and female Suffolk cross Mule lambs were used in a 2 × 2 factorial experiment to investigate the effect of autumn shearing and sex on growth performance over 46 days before slaughter. Lambs were penned individually outdoors and given pelleted lucerne ad libitum.

Shearing increased average food intake by 0·072 (P<0·05), live-weight gain by 0·149 (P<0·01) and carcass weight by 0·058 (P<0·05). It is concluded that shearing is financially worthwhile in climatic conditions such as the present experiment.
Studies on blood acid-base status and muscle metabolism in working bullocks
Authors: Upadhyay R. C. , Madan M. L.
Published: September 2010

Haryana and crossbred (Holstein × local Haryana) bullocks were subjected to work under heavy loads in summer. During the work, bullocks exhibited distress symptoms. After work, rectal temperature, respiration rate, heart rate and minute volume increased significantly, the average pO2content increased, muscle lactic acid increased and creatine phosphate level declined. From the results it was evident that oxygen availability in blood improved during work. Despite the enhanced oxygenation of blood, there was accumulation of lactic acid in muscle. This indicated a certain degree of tissue hypoxia, which probably brought about fatigue earlier.
A model to maximize hay intake when formulating rations for pregnant ewes
Authors: St C. Neal Heather D. , France J. , Orr R. J. , Treacher T. T.
Published: September 2010

A model is described, which maximizes hay intake in the formulation of rations for pregnant ewes in the last 6 weeks of pregnancy. A regression of hay intake upon hay digestibility, concentrate level, ewe live weight, number of foetuses carried and week of pregnancy, derived from an experiment on individually-recorded ewes, is used as the intake constraint in a linear programme. This is solved in an interactive program which can be implemented on several makes of microcomputer. The intakes of hay predicted by the model are lower than those reported elsewhere, reflecting the more accurately recorded intakes of the original experiment compared with most other published data. The rations formulated by the model show that in weeks 16 to 18 of pregnancy hay could provide most of the ewes' requirements and especially when hays of high metabolizable energy concentration are used. The ease of changing the values of the inputs and the speed of the ration formation enable any number of rations to be formulated quickly for a range of hays and individual conditions.
Changes in body composition relative to weight and maturity of Australian Dorset Horn rams and wethers. 3. Fat partitioning
Authors: Butterfield R. M. , Thompson J. M. , Reddacliff K. J.
Published: September 2010

The effect of castration on fat partitioning in mature animals and on the maturing patterns for fat depots relative to total body fat was examined using slaughter and dissection data from 20 Dorset Horn rams and 20 Dorset Horn wethers. Animals were slaughtered at 6 kg intervals from 18 kg live weight to maturity. Five rams and eight wethers were classified as mature.

In the mature animals the partitioning of fat differed for the rams and wethers in that the rams had a lower proportion of subcutaneous fat, and higher proportion of intermuscular and mesenteric fat than the wethers. However, the proportions of total carcass dissectible fat (i.e. subcutaneous plus intermuscular fat) and of the total non-carcass depots (i.e. kidney plus channel fat, omental, scrotal and thoracic fat) did not significantly differ between rams and wethers.

The maturity coefficients of individual fat depots of rams and wethers were not significantly different and six of the nine depots were average maturing relative to total body fat. The intermuscular and thoracic fat depots were early maturing (maturity coeffient q= 1·19, 2·26 respectively), and the omental depot was late maturing (q= 0·52).

Comparison of the partitioning of fat in rams and wethers reflected the differences in the mature animals when made at either the mean weight or at the mean stage of maturity, as the maturing patterns of most depots were not greatly different from that of total fat.
Relationship between central performance test for growth in Hereford bulls and growth and carcass traits of progeny
Authors: Baker R. L. , Wickham B. W. , Morris C. A.
Published: September 2010

Four central performance tests of growth in Hereford bulls from about 10 to 19 months of age on pasture were conducted in New Zealand. From the 100 bulls performance tested 63 were representatively sampled, including bulls with high and low performance test rankings, and progeny tested in dairy herds. Crossbred progeny were purchased from the dairy herds at 3 to 4 months of age, assembled in one location and reared together on pasture for 14 to 15 months prior to slaughter. Regressions of progeny growth and carcass traits on a number of different performance traits for growth of their sires were in almost all cases not statistically significant. The effective heritability, from offspring-sire regression, was 0·07 (s.e. 0·05) for final live weight and 009 (s.e. 0·06) for post weaning gain from about 200 to 550 days of age. It is concluded that central performance tests, as presently conducted in New Zealand, are of limited value for ranking breeding values of bulls for growth. Possible reasons for these results are discussed. It is suggested that pre-test environmental effects and age at the start of the central test are critical factors.
The performance of weaned lambs offered diets containing different proportions of fresh perennial ryegrass and white clover
Authors: Gibb M. J. , Treacher T. T.
Published: September 2010

Six weaned lambs were allocated to each of eight restricted feeding treatments with 1·00, 0·85, 0·71, 0·57, 0·43, 0·29, 0·15 or 0 of the diet as perennial ryegrass and the remainder as white clover, and to one ad libitum treatment with perennial ryegrass offered alone. A further six lambs were offered white clover ad libitum starting on day 15. Lambs on the restricted treatments received the same daily allowance of dry matter relative to live weight, adjusted at weekly intervals to allow the greatest possible intake without any rejection of herbage. Fresh cut herbage was offered daily and measurements were made over 69 days. Twelve additional lambs were slaughtered at the beginning of the experiment, and all lambs on restricted treatments were slaughtered at the end.

Increasing the proportion of clover in the diet increased the intake of nitrogen, empty-body-weight gain, carcass weight gain and nitrogen retention. When herbage was offered ad libitum, lambs ate significantly more clover than ryegrass and gained weight faster.

The weight of gut contents decreased as the proportion of clover in the diet increased. The digestibility of the organic matter, energy and nitrogen of the mixed diets simply reflected the digestibilities of the two herbages and their proportions in the mixture.
The effect of age on tooth loss and the performance of Masham ewes
Authors: Newton J. E. , Jackson Caroline
Published: September 2010

The rate of incisor, pre-molar and molar tooth loss was studied in two groups of Masham ewes, one from 8·75 to 12·25 years of age, and the other from 7·25 to 9·25 years of age. Incisors were lost at the rate of 0·93 per year in group 1 and pre-molars from the lower jaw at the rate of 1·04 per year. The rate of loss of molars from the lower jaw and pre-molars from the upper jaw was much slower, whilst there was virtually no loss of molars from the upper jaw.

Mean litter size declined gradually from age 7 in group 1, but there was no decline up to age 9 years in group 2. Lambing percentage declined gradually from age 6 years, with a marked drop after age 10 years caused by an increase in barrenness and lamb mortality. Selling percentage also began to decline from age 6 years but dropped sharply after age 9 years following an increase in the number of lambs having to be reared by hand. Ewe live weight, lamb birth weight and lamb growth to 4 weeks of age showed no decline up to 12 years of age.
Economic weights and index selection of milk production traits when multiple production quotas apply
Authors: Gibson J. P.
Published: September 2010

The generation of profit in dairy production can be approximated by a generalized profit equation, which is a function of the genotype of the animals used. In the absence of legislated quotas on production, the economic weights for traits contributing to profit, for use in a selection index, have been shown to be simple functions of the partial derivatives of profit with respect to output of the traits. These functions reflect the fact that output in most agricultural industries will already be maximized, either because of saturated markets or limitations on total inputs. When a single quota applies, different functions result, which reflect the downward rescaling of enterprise size as output per animal of a trait under quota is increased. Difficulties arise when multiple non-independent quotas apply, such as in the United Kingdom (UK) milk market where quotas are triggered by both milk volume and fat concentration. The functions describing the economic weights are then dependent on the form of the dependency between the quota criteria and on the genetic change resulting from the applied selection index. Economic weights for milk volume, fat, protein and lactose yield applicable to Holstein'Friesian cattle in the UK were found to be –1·6 p/1, 76·6 p/kg, 170·0 p/kg and 7·0 p/kg, scaled to 1986 prices. These weights would not change much if the quota were changed to fat yield only. Use of appropriate selection indexes should result in genetic increases of milk volume, fat, protein and lactose yield, with gradual increases in fat and protein concentrations and the fat to protein ratio. In most situations, selecting on the combined evaluation for fat plus protein yield would be a simple procedure with high efficiency (0·995 of maximum efficiency).
The association between non-fleece pigmentation and fleece pigmentation in Corriedale sheep
Authors: Fleet M. R. , Stafford J. E.
Published: September 2010

The phenotypie associations between scores for various types of non-fleece pigmentation and concentration isolated pigmented wool fibres in the fleece (experiment 1 and 2) or the piebald phenotype (experiment 3) were studied in Corriedale hogget ewes. These sheep were selected on the basis of either degree of nose skin pigmentation (experiment 1), presence or absence of pigmented fibres at the horn sites (experiment 2) and presence or absence of the piebald phenotype (experiment 3). Among affected fleeces the concentration of isolated pigmented fibres (PFC) had high correlations (0·96 and 0·97) with the proportion of staples affected, which indicates that when PFC is high the isolated pigmented fibres are widely distributed throughout the fleece. Three types of non-fleece pigmentation had significant (P < 0·05) positive correlations with PFC in experiments 1 and 2. These were pigmented skin on the nose lips (0·23 and 0·18; P < 0·05), pigmented fibres at the horn sites (0·34 and 0·30; P < 0·01) and pigmented fibres on the legs (0·36 and 0·29; P < 001). The pigmentation of skin or fibres in non-fleece areas was predominantly black/grey and there were usually significant (P < 0·05) positive correlations between the various types of non-fleece pigmentation. In experiment 3, piebald sheep were found to have higher scores for black/grey fibres on the ears (P < 0·001), face (P < 0·01) and horn sites (P < 0·05) and for black/grey skin under the tail (P < 0·01) than non-piebald sheep.
Efficiency of utilization during pregnancy and lactation in the ewe of the protein reaching the abomasum and truly digested in the small intestine
Authors: Ngongoni N. T. , Robinson J. J. , Aitken R. P. , Fraser C.
Published: September 2010

In six experiments carried out on individually penned Finn Dorset ewes estimates were made of the quantities of non-ammonia nitrogen (NAN) reaching the abomasum and truly digested in the small intestine. For experiments 1 and 2 which each involved 33 ewes given a complete diet of milled hay and concentrates supplemented with varying amounts of a good-quality fish meal during late pregnancy, the overall regression estimate for the daily amount of truly digested NAN required for zero N retention (ewe plus conceptus) was 438 mg/kg M0·75 (441 and 434 for experiments 1 and 2 respectively). The coefficients for the efficiency of utilization of increments of truly digested NAN and maternal tissue N for net N accretion in the conceptus were 0·48 (s.e. 0·039) and 0·84 (s.e. 0·127) respectively.

In experiment 3, 24 lactating ewes had their diet supplemented with either soya-bean meal or fish meal. There was no effect of protein source on the amounts of NAN reaching the abomasum in ewes fitted with an abomasal cannula or on milk yield and these observations confirmed the unusually high degradability (measured by the polyester bag technique) of the fish-meal protein in the rumen. For experiments 4, 5 and 6 a total of 36 ewes were used to test the efficiency with which the NAN truly digested in the small intestine was used for the synthesis of milk protein. In the absence of data on the possible contribution of body tissue N to milk N the coefficient for the apparent efficiency of utilization of truly digested NAN when the ewes were given a basal diet containing approximately 10 g crude protein per MJ metabolizable energy was 0·63. For those ewes receiving the basal diet supplemented with either soya-bean meal, fish meal or blood meal the coefficients for the efficiency of utilization for the production of milk N of the increments in truly digested NAN supplied by the three protein sources were 0·61, 0·54 and 0·29 respectively. It is suggested that the low coefficient for blood meal may be due to its low content of methionine.
The effect of contrasting silages offered in mid and late pregnancy on the performance of breeding ewes
Authors: Chestnutt D. M. B.
Published: September 2010

Early-cut, precision-chopped (EP) and late-cut, flail-harvested (LF) silages were offered ad libitum to breeding ewes during mid and late pregnancy in two experiments. Silages offered in late pregnancy were factorially arranged with silages offered in mid pregnancy giving four silage treatments. Voluntary drymatter intake, ewe weight change, lamb birth weight and blood levels of 3-hydroxybutyrate (3-OHB) and non-esterifiable free fatty acids (NEFA) were measured. The intake of LF silage was proportionately 0·61 and 0·72 of that of EP silage in mid and late pregnancy respectively. While type of silage given in mid pregnancy did not affect the mean silage intake in weeks 15 to 20 of pregnancy, the rate of decline in intake was higher and the intake during week 20 of pregnancy was lower following the feeding of EP silage in mid pregnancy. Despite a considerably lower level of body reserves associated with LF silage given in mid pregnancy, there was little effect on levels of 3-OHB or NEFA in late pregnancy or on lamb birth weight.
Growth of cattle twins on dairy farms with high and low yielding herds
Authors: Wiener Gerald
Published: September 2010

Sixty-five pairs of two-egg cattle twins of three breeds, Ayrshire, Friesian, and Shorthorn, were split at random within a week of their birth between two groups of commercial dairy farms. One group was selected for a relatively high average milk yield of the adult dairy herd (group A) and the other for relatively low average yield (group B). The body growth of the twins up to nearly 4 years old is described in this paper. Very significant differences in growth developed in consequence of the split between the groups. Twins on the A farms became larger than their co-twins on the B farms. Average differences between the groups increased for the first year or 18 months and then began to fall away, but had not disappeared at the last age (198 weeks) studied. The various body parts behaved differently i n response to the treatments or environments associated with the two groups of farms. Thus, at the ages studied, the twins on the ‘high’ yield farms differed in conformation from their co-twins on the ‘low’ yield farms. In addition to the differences arising between the members of split twin pairs, there were also differences in body size between the pairs. Breed was not apparently important as a factor affecting the growth differences arising between the two treatments.
A comparison of testing schemes for pigs
Authors: Smith Charles
Published: September 2010

Using extensions to Robertson's (1957) method for finding the optimum test design, factors affecting the improvement from testing were studied. Other than the heritability, the ratio of the number tested (N) to the number required for breeding stock (T) has the largest effect on the improvement expected, the improvement being roughly proportional to the logarithm of this ratio. The type of family and the number in the test group which compose the optimum design, also depend largely on the ratio N/T. Accuracy in evaluation is required when only few animals are selected (N/T high), but small test groups from large families are necessary when large numbers of breeding stock are required (N/T low).

Testing schemes differ basically in their selection procedure and only secondarily in their designs. The advantage resulting from the tested animals being themselves selected is in proportion to what part they constitute of the total selected.

Another consideration is how the testing is integrated with the population breeding structure. Maximum improvement will be obtained if the testing facilities are restricted to a nucleus group of breeders, and full opportunity for selection is made in their stocks. The increased improvement this providesis accumulated in this nucleus group of herds and gradually passed down to the rest of the herds. Otherwise the improvement will be greatest when each breeder can use sires from families which have performed well in thetesting.
An investigation into self-feed silage practices
Authors: Hodges John , O'Connor L. K.
Published: September 2010

1. A survey of management practices associated with the self-feeding of silage was carried out on a group of 130 farms during the winter of 1958-9.

2. The majority of farmers housed their cows in covered yards and allowed them free access to silage stored in a roofed surface clamp.

3. An average of 56 square feet per cow of covered yard and, under free access, 9·7 inches of face width per cow were allowed.

4. The average estimated consumption of silage over the whole feeding period was 2·12 cubic feet per cow per day. Where the feeding face was lit at night, the estimated silage consumption was 0·27±0·10 cubic feet per cow per day more than on other farms. There was also a suggestion that on farms where hay and/or straw was fed, the consumption of silage was less than on the remainder.

5. Levels of milk production were similar and concentrate feeding were slightly lower than those found in National Milk Recorded and Private Milk Recorded herds.
Carcass length in the bacon pig; its association with vertebrae numbers and prediction from radiographs of the young pig
Authors: King J. W. B. , Roberts R. C.
Published: September 2010

Vertebrae counts made on 504 Large White and 550 (Wessex × Large White) pigs showed an association with carcass length but not with other carcass traits. For each additional vertebra there was an increase in length of approximately 15 mm.

Another group of 313 piglets from 36 litters were X-rayed at around 9 days of age in order to predict their ultimate carcass length. After correction for sex and variations in weight at slaughter it was found that the number of thoracic and lumbar vertebrae together accounted for 14% of the remaining variation in carcass length. Improved accuracy of prediction, accounting for 29% of the variation was obtained with a multiple regression equation using as independent variables: the skeletal length of the young pig as measured on its radiograph, its weight at birth and X-raying and the number of lumbar vertebrae. From measurements made on the carcass it i s suggested that X-raying of the bacon pig to measure the length of the first four lumbar vertebrae, would, in conjunction with an earlier determination of vertebrae number, enable a much improved prediction of carcass length to be made.

The incidence of various vertebral variations is noted and in particular the occurrence of one pig with only six cervical vertebrae.
The effect of hormones on growth rate and carcass quality of fattening lambs and hoggets
Authors: Burgess T. D. , Lamming G. E.
Published: September 2010

The effects on average daily gain of a 12 mg. implant of diethylstilboestrol has been tested in male suckling lambs and in male hoggets. In both types stilboestrol produced some mammary stimulation. One case of rectal prolapse was encountered in the hoggets. In suckling lambs, treatment did not significantly increase rate of gain nor significantly affect any of several carcass characteristics studied. In hoggets, treatment produced a highly significant increase in rate of gain (33%), a highly significant increase in pelt weight and a highly significant decrease in the percentage of fat in the last rib section. It produced a non-significant increase in muscle and bone in the last rib section. Carcass score and dressing percentage were not significantly affected by treatment.

The oral administration of L-thyroxine to suckling female lambs from 30–70 lb. live-weight did not significantly affect the rate of gain or the carcass characteristics studied.
The effect of diethylstilboestrol, hexoestrol and testosterone on the growth rate and carcass quality of fattening beef steers
Authors: Burgess T. D. , Lamming G. E.
Published: September 2010

The use of the hormones, diethylstilboestrol, hexoestrol and testosterone propionate, as growth stimulants in beef cattle has been studied.

The subcutaneous implantation of 60 mg. stilboestrol into steers fattening in yards produced a highly significant increase in rate of gain (65%) and little difference in the yield and quality of the carcass. The implantation of 24 nig. or 36 mg. of diethylstilboestrol or 30 mg. hexoestrol into Friesian bullocks fattening on pasture produced highly significant increases in rates of gain (29%, 48% and 33% respectively). No significant difference was found in the rates of gain produced by these three treatments.

The oral administration of 10 mg. diethylstilboestrol per head per day for 168 days or the oral administration of 20 mg. rising to 40 mg. testosterone propionate per head per day for 154 days to dizygotic twin steers on equal feed intake significantly increased rate of gain by 15% and 21% respectively Feed efficiency as measured by the pounds of feed required to produce a pound of gain was significantly improved by both treatments. Carcass yield and carcass quality were not significantly affected by either treatment. No significant differences were found between the two treatments.

Examination of the thyroid and adrenal glands of treated and untreated steers revealed no consistent changes in size due to treatment. The gonadotrophin and thyrotrophin content of the anterior pituitary glands of treated and untreated cattle were compared using the male chick bioassay. The results showed that a lower gonadotrophin content was not a factor associated with the extra growth due to treatment, but in two out of three experiments there was some evidence that sex-hormone treatment leads to a mild hyper-thyroidism which, in turn, resulted in a decrease in the thyrotrophin content of the anterior pituitary gland. It was concluded that hyperactivity of the thyroid gland was probably more important in accounting for the extra growth than hyperactivity of the adrenal cortex.
Studies on liquid skim milk for growing pigs. The effect of its abrupt removal from the diet and of supplementation with copper sulphate or amino acids
Authors: Barber R. S. , Braude R. , Hosking Zena D. , Mitchell K. G.
Published: September 2010

Results of four experiments involving a total of 124 pigs covering the growth period between about 40 and 210 lb. live-weight indicated that:

1. The growth rate and efficiency of food utilisation of pigs receiving liquid skim milk up to a maximum of 5¼ pints per head per day, was better than that of pigs receiving a balanced all-meal diet. This was equally so whether the liquid skim milk was fed throughout the growing period or was abruptly removed from the diet at either about 75 lb. or 120 lb. live-weight, provided the all-meal diet fed subsequently contained adequate protein.

2. The addition of 0·1% copper sulphate to the meal fed with liquid skim milk significantly improved the growth rate and efficiency of food conversion.

3. The addition of 0·2% dl-lysine and 0·1% dl-methionine to the meal fed with liquid skim milk had no effect on the performance of the pigs.

4. Withdrawal of a protein supplement from the rations of pigs after they reached about 120 lb. live-weight adversely affected their performance.
The effect of plane of nutrition during rearing on growth, production, reproduction and health of dairy cattle. III. Milk production during the first three lactations
Authors: Crichton J. A. , Aitken J. N. , Boyne A. W.
Published: September 2010

1. The fat-corrected milk yields and butterfat and solids-not-fat percentages of the milk of heifers reared on the four planes of nutrition described in part 1 of this series are compared, i.e. high high (HH), high low (HL), low low (LL), low high (LH).

2. The most significant feature of the F.C.M. yields was the poor performance of the HL group in each lactation. When variability due to differences in lactation length had been eliminated the yields of the HL group in the first and second lactations were found to be significantly lower than those of the other treatment groups.

3. In the first lactation the mean B.F. percentages of HH, LH, HL and IX animals were respectively 3·92, 3·85, 3·81 and 3·74. These differences were significant at the 5% level. When the weekly yields and percentages of the HH and LL groups were compared it was found that the difference was almost entirely confined to the first 6 weeks of lactation. In the second and third lactations the mean B.F. percentages of all groups were similar.

4. Only in the second lactation were the S.N.F. percentages significantly different between groups. No explanation can be offered.

5. A comparison of the live-weight changes of HH and LL animals following successive calvings showed that recovery by the LL animals was most rapid immediately following first parturition and also during the first and second dry periods.

6. The plane of nutrition during rearing had no apparent effect on the pattern of change in milk yield and composition between first and third lactations, except that HH animals showed a more uniform rate of fall in S.N.F.% between one lactation and the next compared with the other three groups. Heifer lactations were longer and the milk had higher contents of B.F. and S.N.F. than later lactations.

7. The estimated feed costs of the rearing from birth to first calving of the HH, LH, HL and LL animals were markedly different.

8. The results are discussed in relation to practice.
Relationship between meat colour and feed efficiency in pigs
Authors: Osińska Zofia , Kielanowski J.
Published: September 2010

Data from Danish Progeny Testing Stations were used to investigate the relationship between the colour of meat and feed efficiency in pigs. For groups slaughtered during the summer there was a highly significant correlation. As the amount of feed consumed per unit live-weight gain declined so the meat became paler. For groups slaughtered in winter and for data pooled over the whole year, there was no significant correlation. Possible explanations of these findings are discussed.
Supplementation of bacon pig rations by aureomycin and two levels of copper sulphate
Authors: Bellis D. B.
Published: September 2010

A trial has been carried out to determine the effects of supplementing bacon pig diets with 125 and 250 ppm. copper (as copper sulphate) and/or aureomycin (14·4 ppm.). A total of 288 pigs were fed ad lib. from 40·100lb., and restricted-fed thereafter to bacon weight (200 1b.). Growth rate was increased by 125 ppm. copper, 250 ppm. copper, and aureomycin during the ad lib. feeding period. The magnitude of the responses was about the same in each case.

During the fattening stage from 100 1b. to bacon weight, 125 ppm. copper or aureomycin increased food conversion efficiency; 250 ppm. copper however improved growth rate also. There was probably some additive effect of 125 ppm. copper and aureomycin when fed together, but it is unlikely that such an effect occurred with the higher level of copper and aureomycin.

The liver copper content of pigs fed 125 ppm. copper was 3 times higher than that of the controls; 250 ppm. copper increased liver copper storage about 18·fold.

The similarity in response of copper and aureomycin feeding to pigs is discussed. It is concluded that, under the conditions of the trial, their mode of action is similar. Under similar conditions in general farm practice there is unlikely to be any economic advantage in supplementing pig diets containing 250 ppm copper with aureomycin; however, the bacterial environment may sometimes be such that additional benefit will be obtained by joint supplementation.
The effect of implanting testosterone alone or with oestradiol on the growth rate and carcass quality of fattening female hoggets
Authors: Shorthose W. R. , Lamming G. E.
Published: September 2010

Two trials were completed using a total of 135 female hoggets from 5 to 7 months of age. The effect of implanting 15 or 30 mg. testosterone propionate or 2·5 mg. oestradiol benzoate plus 25 mg. testosterone propionate was assessed on average daily gain, slaughter characteristics and carcass yield. In the second trial some additional data were obtained on carcass quality.

No significant effect of testosterone with or without oestradiol could be demonstrated on average daily gain, carcass yield, carcass score or the proportion of retail cuts in the carcass. There was some indication that the treatment could yield carcasses with less subcutaneous fat without diminution of eye muscle size.
The nutrition of the early-weaned calf. I. The effect on nitrogen retention of diets containing different levels of groundnut meal
Authors: Whitelaw F. G. , Preston T. R. , Ndumbe R. D.
Published: September 2010

1. Nitrogen balance studies were made on eight early weaned calves given diets varying in crude protein content from 11·6% to 22·6% in dry matter.

2. Nitrogen retention increased significantly as the level of crude protein increased to 19·20%; there was no further increase in nitrogen retention when the level of protein was increased to 22·6%.

3. Dry matter digestibility and apparent digestibility of dietary nitrogen rose progressively as the level of crude protein increased.

4. The nitrogen retention of calves fed diets adequate in protein was calculated to be 2·88 g. per 100 g. gain in body weight.
The effect of different oestrogens and oestradiol plus progesterone on the growth and carcass characteristics of fattening male hoggets
Authors: Shorthose W. R. , Lamming G. E.
Published: September 2010

A comparison has been made in five flocks with a total of 473 sheep of the effect of 15 mg. diethylstilboestrol (DES.) as a paste, 15 mg. hexoestrol as an implant, and 5·0 mg. oestradiol benzoate plus 50 mg. progesterone (O.+P.) as two implants, on the growth rate and slaughter characteristics and carcass grading of fattening male hoggets.

In those flocks where the plane of nutrition was adequate, all hormone treatments resulted in a significant increase in live-weight gain. During the first 24–40 days, DES. paste resulted in significantly greater daily live-weight gain compared to hexoestrol or O.+P. in two out of five flocks, but over the whole period there were no significant differences between these treatments. In one flock which was on a lower plane of nutrition there were no significant effects of hormone treatment.

The hormone treatments resulted in extra carcass weight, extra pelt weight but no change in killing-out percentage or in carcass grade. There were no significant differences between treatments in the slaughter characteristics studied.
A report on the treatment of beef cattle with tranquilisers and antibiotics
Authors: Dodsworth T. L. , Ball C.
Published: September 2010

The results are given from trials which were designed to demonstrate the effects of feeding antibiotics and a tranquiliser to beef cattle. In Trial 1 the feeding of 80 mg. aureomycin daily produced no significant effect. In Trial 2 the feeding of neither 2·5 mg. hydroxyzine nor 80 mg. terramycin nor the two combined produced any significant effect except to depress the level of intake of dry-matter over the whole trial period. This reduction in drymatter intake did not lead to an increase in efficiency of conversion (lb. dry-matter intake per lb. live-weight gain). In trial 2 the tranquiliser tetrahydrozoline was unsuccessfully used at the beginning of the trial in an attempt to reduce the loss in live-weight suffered when the animals were tied up.
A study of the milk yield of three strains of Scottish Blackface ewes in two environments
Authors: Munro Joan
Published: September 2010

Milk yields of three strains of Scottish Blackface ewes (Lewis, Lanark and Newton Stewart) were recorded over periods of eight weeks on reseeded pasture and on hill pasture. There were no differences in milk yields between strains in the respective environments, but there were significant differences between environments in all three strains.

Relationships between udder width and milk yield were investigated in the Lewis and Newton Stewart strains.

Analyses of milk samples (taken by hand) showed there were no significant differences in the contents of fat or solids-not-fat. There was evidence that the percentage of fat and solids-not-fat in all groups tended to decrease initially and then to increase gradually as lactation advanced.

Live-weights of the ewes were compared and it was shown that the Lewis ewes were characteristically lighter than either of the other strains.

On the reseed all lambs were approximately equal in live-weight and condition. On the hill the Lewis lambs were inferior in weight and condition, and it is suggested this reflected the Lewis strain ewes' grazing preferences for higher ground.