bluuebunny/crossref_metadata_2025 huggingface dataset:
Economic weights from profit equations: appraising their accuracy
Authors: Bright G.
Published: September 2010

Despite much discussion on the use of simple profit equations to estimate economic weights, no study appears to have tested the accuracy of this method. This paper carries out such a test from the viewpoint of the individual farmer by comparing economic weights calculated in the normal way with results gained from a more empirically acceptable, non-linear equation. Although the study concludes that simple profit equations are likely to be sufficiently accurate in most circumstances, further consideration needs to be given to a series of time periods and the industry and economy at large.
The effect of implantation of lowland ewes with melatonin on the time of mating and reproductive performance
Authors: Haresign W.
Published: September 2010

Two trials, involving a total of 1006 Mule ewes and 1862 Suffolk-× ewes, were conducted to investigate the ability of implantation with melatonin to induce early breeding in lowland sheep flocks. Dates of implantation ranged from mid May to late June for Suffolk-× flocks and mid May to early July for Mule flocks.

From the mating patterns obtained it is suggested that the optimum implantation date is mid May to mid June for Suffolk-× ewes and mid June to mid July for Mule-type ewes.

Melatonin treatment also significantly increased the mean litter size per ewe exposed to the ram (resulting from a 6-week mating period) when the data were pooled across flocks, but the magnitude of this effect varied across flocks. Part of this overall mean increase in Mule ewes (+0·84 and +0·50 extra lambs per ewe in trials 1 and 2 respectively) was due to an increase in the proportion of ewes mating and lambing and part of it (+0·13 and +0·17 extra lambs per ewe, respectively) was due to an increase in litter size per ewe pregnant. In the Suffolk-× ewes there was evidence that the overall mean benefit following implantation with two implants (+0·31 extra lambs per ewe) was greater than that following implantation with one implant (+0·14 extra lambs per ewe), with all of the increase at the lower dose level and +0·21 extra lambs per ewe at the higher dose being due to an increase in litter size per ewe pregnant.
In vivo prediction of goat body composition by computer tomography
Authors: Sørensen M. T.
Published: September 2010

Computer tomography (CT) was evaluated as a method to predict body composition of live goats. Forty-one lactating goats were scanned. CT values (X-ray attenuation data) representing soft body tissues were summarized into 140 frequencies. By principal component analysis the 140 multicollinear frequencies were reduced to six orthogonal principal components at the loss of only 0·032 of the original variation.

Following scanning at four positions the goats were slaughtered, dissected and the data analysed. Seven compositional traits (water, protein and fat from the carcass and non-carcass parts, and total energy of the body) were regressed on live weight and the six principal components from each of five CT data sets (data from the four scan positions and pooled data) in a stepwise linear regression procedure. Models from the pooled data set were further evaluated in a cross-validation procedure. Compared with evaluation based on calibration only, a more simple and precise model was chosen as the best by this procedure.

After addition of CT variables in prediction equations already comprising live weight, cross-validation deviations were reduced by 0 for carcass water, 0 for carcass protein, 0·48 for carcass fat, 0·14 for non-carcass water, 0·23 for non-carcass protein, 0·73 for non-carcass fat, and 0·73 for total energy. These results show that CT is a valuable in vivo method for predicting body fat and energy, but less valuable for body water and protein.
Patterns of daily food intake in growing pigs
Authors: de Haer L. C. M. , Merks J. W. M.
Published: September 2010

Food intake patterns of growing pigs given food ad libitum in individual and group housing were derived from food intake recordings with IVOG®-stations. The IVOG-station is a feeding station that records animal identification number, time, duration and amount of food intake during each visit of a pig to the food hopper. Data were collected in three testing batches of 90 Dutch Landrace pigs each, housed in 10 individual pens and in 10 group pens of eight pigs per batch.

Based on survival analysis theory, intervals between visits shorter than 5 min (which was used as meal criterion) were regarded as within-meal intervals and these visits were grouped into meals. In group housing, food intake per day and rate of food intake had no significantly non-normal distribution. In individual housing, rate of food intake, food intake per day and number of meals per day had no significantly non-normal distribution. In individual housing rate of food intake, food intake per day and number of meals per day had no significantly non-normal distribution. All traits were normally distributed after discarding extreme values, except food intake and eating time per visit and per meal. In group housing these traits were not significantly non-normally distributed after logarithmic transformation.

Pigs housed in groups ate faster, had a higher food intake per meal but less meals per day, less eating time per day and a lower daily food intake than pigs penned individually. During the day two peaks of feeding activity occurred, especially in group housing: one in the morning and one in the beginning of the afternoon.

A distinction was made between meals with a major contribution to daily food intake and meals of minor importance. In group housing, 69% of the daily number of meals accounted for proportionately 0·87 of daily food intake and 0·83 of daily food intake time. In individual housing 39% of the meals accounted for proportionately 0·90 of the daily food intake and 0·79 of the daily eating time.

Higher repeatabilities of day to day recordings of food intake traits, were found when estimated within 2-week periods compared with months or with the total fattening period.
Genetic components of growth and ultrasonic fat depth traits in Meishan and Large White pigs and their reciprocal crosses
Authors: Haley C. S. , d'Agaro E. , Ellis M.
Published: September 2010

Genes from the Chinese Meishan pig have the potential to enhance reproductive performance of European pigs. In order to allow prediction of the impact of Meishan genes in a range of alternative improvement programmes all traits of economic importance must be evaluated and genetic crossbreeding effects estimated. Entire male and female pigs of four genotypes, purebred Meishan (MS) and Large White (LW) pigs and both reciprocal Fl crossbred genotypes (MS ♂ × LW ♀ and LW ♂ × MS ♀), were farrowed in Edinburgh and subsequently performance tested at either Edinburgh or Newcastle. In Edinburgh, animals were penned in groups of four and fed ad libitum between pen mean weights of approximately 30 and 80 kg. At the end of test fat depths at the shoulder, last rib and loin were measured ultrasonically. In Newcastle, animals were penned in groups of six and fed ad libitum between pen mean weights of approximately 30 and 70 kg. Genotypic means and genetic crossbreeding effects (additive and heterosis direct effects and additive maternal effects) were estimated using restricted maximum likelihood.

When compared with the LW, the direct additive effect of genes from the MS produced increased growth rate up to the time of weaning, no change in growth rate between weaning and start of test and greatly reduced growth rate during the performance test. The maternal additive effect of genes from the MS was to reduce growth rate up to the time of weaning, with little effect thereafter. There was substantial direct heterosis for growth rate in all periods measured, but heterosis was less in males than in females during the performance test. The combined effect was such that, within sex, the LW and the two crossbred genotypes were of similar ages when they reached 70 and 80 kg, but MS pigs were 38 to 60 days older. The direct additive effect of MS genes was to increase subcutaneous fat levels and there was little evidence for the effects of maternal genes or direct heterosis on these traits. There was a direct additive effect of MS genes reducing food intake and increasing food conversion ratio and there was direct heterosis for increased food intake. There were significant interactions between genotype and sex. Male and female LW pigs had a similar performance but male MS pigs had slower growth rates on the performance test with lower food intakes, food conversion ratios and subcutaneous fat levels than the females.
A note on the influence of negative gradients on the energy expenditure of donkeys walking, carrying and pulling loads
Authors: Dijkman J. T.
Published: September 2010

The extra energy used for walking on the level and on negative gradients above that used when standing still (Ew) (J/m per kg live weight) was measured in two entire male donkeys (Equus asinus). Ewwas not affected by speed within the measured range (V = 0·6 to 1·3 m/s) but gradient (0, −10%, −15%) had a significant effect Ew−10%= 0·97 (s.e. 0·02), Ew−10%= 0·55 (s.e. = 0·03) and Ew−15%= 0·67 (s.e. 0·03).

The extra energy cost of carrying loads (Ec), defined as J/m per kg carried was measured using the same animals. Loads were placed over the animals shoulders and speed was varied within the range 0·6 to 1·3 m/s (Eclevel= 1·1 (s.e. 0·04), Ec−10%= 2·7 (s.e. 0·17) and Ec−15%= 3·3 (s.e. 0·20) were significantly different.

The energy cost of pulling loads (Ep) (f/m per kg) was measured while the animals pulled loads up to proportionately 0·17 of their live weight. The animals wore a breast-plate harness and walking speed was varied within the range 0·6 to 1·3 m/s. Mean values were 26·5 (s.e. 0·72) on the level, 15-3 (s.e. 1·2) on the −10% gradient and 6·2 (s.e. 0·43) on the −15% gradient.

The two donkeys used in this experiment were more efficient in both carrying and pulling loads than oxen and buffaloes. Negative gradients have a significant effect on energy consumption and when estimating the energy expenditure of working animals this factor should be taken into account.
A note on the development of behaviour of intensively managed piglets in the humid tropics
Authors: Kabuga J. D. , Annor S. Y.
Published: September 2010

The behaviour development of intensively managed piglets, pre-weaning, in the hot humid tropics was studied with 18 litters of the Large White breed. The effect of age, sex and period of day (morning and afternoon) on the frequencies of some 14 behaviours from 1 day after birth until 34 days of age were examined using focal animal sampling on 36 piglets. Time spent lying and standing in contact declined. Time spent lying and standing alone, walking and the frequency of tail wagging, rubbing and scratching body parts, playing and fighting all significantly increased with age (P < 0·05). There was a significant (P < 0·05) linear trend, with age, in the eating of concentrates, which began at 2 weeks of age, and drinking water which occurred on the day after birth. Piglets were more active in the hot afternoons (12.00 to 16.00 h) than the cold mornings (08.00 to 12.00 h). There were no significant differences between males and females in any behavioural pattern (P < 0·05).
Voluntary food intake, live-weight change and lactation performance of crossbred dairy cows given ad libitum Pennisetum purpureum (napier grass var. Bana) supplemented with leucaena forage in the lowland semi-humid tropics
Authors: Muinga R. W. , Thorpe W. , Topps J. H.
Published: September 2010

Scarce and poor-quality food resources limit smallholder dairy production in the tropics. Food resources for zerograzing may be improved by intercropping Pennisetum purpureum (napier grass) with Leucaena leucocephala leguminous hedgerows. To evaluate dairy cow performance from this alley cropping system, 36 Ayrshire/Brown Swiss × Sahiwal cows in a 2×3 factorial design were individually fed from the 3rd week of lactation for 14 weeks on diets of napier fodder harvested at 1·0 m or 1·5 m and offered ad libitum, supplemented with 0, 4 or 8 kg fresh weight leucaena fodder. Average daily milk yield during the 2nd week of lactation was a covariate in the analyses of milk yield, and post-partum live weight a covariate in the analyses of dry matter (DM) intake and live-weight change.

Napier harvesting height and leucaena level had independent effects on performance. Napier height (1·0 m or 1·5 m) significantly (P < 0·01) affected daily napier DM intake (9·3 and 6·8 kg), total daily DM intake (10·5 and 7·9 kg), daily live-weight losses (165 and 490 g) and daily milk yield (8·6 and 6·9 kg respectively). Leucaena supplementation (0, 4 or 8 kg) significantly (P<0·01) increased total daily DM intake (7·8, 9·3 and 10·4 kg), reduced daily live-weight loss (560,235 and 175 g), and increased daily milk yield (7·3, 7·7 and 8·3 kg respectively). The results show that reasonable dairy performance can be achieved in the tropics by supplementing a napier fodder basal diet with leucaena forage, and highlight the importance of the stage of harvesting of the napier fodder. The results are discussed in relation to the nutrient requirements for milk production given by the Agricultural Research Council (1980 and 1984).
Fish-meal supplementation of grass silage given to young growing steers: effect on intake, apparent digestibility and live-weight gains
Authors: Sanderson R. , Thomas C. , McAllan A. B.
Published: September 2010

Seventy-two, 4-month-old, British Friesian steers were used to investigate the effects of feeding a supplement of fish meal on the voluntary intake and live-weight gain by young growing cattle given a well preserved ryegrass silage. The silage was offered either alone or mixed with 50,100 or 150 g fish meal per kg silage dry matter (DM) and the diets were offered either ad libitum or intakes were restricted to 16, 19 or 22 g dietary DM per kg live weight (LW). Intakes were recorded daily, LW weekly and in vivo apparent digestibility over one 7-day period during the 132-day trial.

For animals fed ad libitum, the absolute intake of dietary DM increased linearly with an increase in the level of fish-meal supplementation such that intake when the highest level of fish meal was given was significantly higher (P < 0·01) than when silage was given alone. However, DM intake per unit LW (approx. 24 g DM per kg LW) was not affected significantly (P > 0·05).

Inclusion of fish meal in the diet did not affect the apparent digestibility of dietary DM, organic matter, acid-detergent or neutral-detergent fibre (NDF) although there was a trend for slightly higher (P > 0·05) gross energy apparent digestibility when fish meal was given. Increasing the level of feeding reduced NDF digestibility. The coefficients measured at the 22 g and ad libitum levels of intake were lower (P < 0·01 and P < 0·05 respectively) than that measured at the 16 g DM per kg LW level.

Animals given silage alone to appetite achieved LW gains of 0·6 kg/day. LW gains increased linearly with increasing level of feeding (P < 0·001) and increasing level offish-meal supplementation (P < 0·001).
Evaluation of pig genotypes 2. Testing experimental procedure
Authors: Ferguson N. S. , Gous R. M.
Published: September 2010

An experiment was designed to quantify the specific genetic parameters which will describe the growth potential of a pig. The experiment was conducted in two stages. In the early stage, 11 unimproved crossbred pigs were serially slaughtered at 2, 13 and 23 days of age. In the later phase, 16 pigs were serially slaughtered at 80, 90 and 100 kg live weight. The chemical composition of each of the entire empty bodies was determined. Linear regression analyses were performed on body protein and lipid weights to determine the Gompertz growth parameter (B), mature body protein weight (Pm) and the lipid: protein ratio at maturity (LPRm) The B value for boars was 0-0107 (s.e. 0·00060) per day and for females 0·0120 (s.e. 0·00044) per day. Pm estimates were 38·7 kg and 28·4 kg whilst the LPRm ratios were 2·60 and 3·89 for boars and gilts respectively.
A note on the effect of level of nutrition after weaning on the resumption of reproductive activity by ewes of two Spanish breeds lambing in spring
Authors: Abecia J. A. , Forcada F. , Zarazaga L.
Published: September 2010

Two experiments were carried out from April to September 1990 at Zaragoza, Spain. Fifty-three Rasa Aragonesa (RA) ewes, weaned in April, were studied in experiment 1, whilst 33 Salz (Sz) ewes, weaned in June, were studied in experiment 2. From weaning onwards, the animals were allocated to two groups receiving two planes of nutrition: high (H) and low (L). Mean time between weaning and the first detected oestrus was 113 (s.e. 2·7) and 52 (s.e. 3·0) days for RA and Sz ewes, without any significant effect of the plane of nutrition. Ewes of the H group showed a constantly higher ovulation rate than those of the L group with a significant effect of the plane of nutrition in the second fortnight of August (P < 0·05) and of September (P < 0·001) in RA ewes (1·68 v. 1·29 and 1·89 v. 1·38 corpora lutea for H and L groups, respectively) and in September (P < 0·01) in Sz ewes (2·53 v. 2·00 corpora lutea for H and L groups).

In conclusion, a slightly higher plane of nutrition after weaning in these sheep breeds, lambing in spring, cannot advance either the reproductive resumption or increase the ovulation rate of the first cycle. The high plane of nutrition after weaning exerts a significant effect on the ovulation rate in the medium term, in the early breeding season.
A note on the estimation of the body fat, protein and energy content of lactating Holstein-Friesian cows by measurement of condition score and live weight
Authors: Gibb M. J. , Ivings W. E.
Published: September 2010

The relationships between body composition, live weight (LW) and subjective condition score (CS) were examined in an experiment in which 54, second to fourth parity, lactating autumn-calving Holstein-Friesian dairy cows were slaughtered at 0, 2, 5, 8, 11, 14, 19, 24 and 29 weeks post partum. Multiple regression analyses showed the weight of fat and the quantity of energy within the body were significantly correlated with both LW and CS. The weight of crude protein showed a linear correlation with LW. These results are discussed and compared with previously published investigations with non-lactating dairy cows.
Effects of fertiliser nitrogen and herbage dry-matter content on herbage intake and digestibility in bullocks
Authors: Holmes J. C. , Lang R. W.
Published: September 2010

1. Two experiments were conducted, the first during May, July and August, 1958, and the second during August 1960. The first experiment measured the intake and digestive efficiency of cattle fed on fresh cut herbage from low-and high-nitrogen manuring treatments with and without irrigation. The second experiment tested the effect of water added to fresh cut herbage on the intake of cattle.

2. Rainfall during the summer of the first experiment was high and irrigation had no effect on any of the criteria used.

3. Although the dry-matter content of the fresh herbage from the high nitrogen treatment was consistently lower than that from the low nitrogen treatment (16·6% compared with 19·7% on average when free of surface moisture) the dry-matter intake was the same at 1·97 lb. dry matter per 100 lb. live-weight, on both herbages.

4. The average digestibility of the high and low nitrogen treated herbage was 77·6% and 75·4%, the difference being significant. No scouring occurred. Digestibility was 78·9% in May, 76·1% in July and 74·5% in August (average of N levels).

5. Rain water carried on the leaf surface was shown to have no effect on dry-matter intake.

6. It is concluded that the dry-matter intake of cattle feeding on fresh herbage is unlikely to be restricted either by a high internal water content in the herbage or by rain water on the leaf surface.
Symptoms of muscular hypertrophy in heterozygous steers
Authors: Mason I. L.
Published: September 2010

1. Some characteristics are described of 10 steer progeny of a Friesian bull which is known to have carried the factor for muscular hypertrophy.

2. On average these steers had a higher birth weight, lighter hide and liver, smaller feet and cannon bones, a lower percentage of fat and higher percentage of lean in the 10th rib joint, than the progeny of three other Friesian bulls reared at the same time and under the same conditions.

3. No one character was an adequate criterion for separating affected from normal progeny. It appears possible that the bull concerned was homozygous for the double muscling gene, and that all his progeny showed one or more symptoms of the condition.
Effects of season of growth and digestibility of herbage on intake by grazing dairy cows
Authors: Corbett J. L. , Langlands J. P. , Reid G. W.
Published: September 2010

1. The intakes of herbage organic matter (OM) and digestible organic matter (DOM) by twenty dairy cows were measured during two periods of strip grazing on one pasture, in spring and late summer of the same year.

2. Results from the first 5-day measurement period in the spring suggested that intakes at this time were restricted primarily because the cows had difficulty in gathering the short herbage. Measurements on ten of the cows continued during a further 5 weeks while the digestibility of the OM of grazed herbage declined from about 80 to 68%. There was a fall of about 20% in DOM intake by the cows during this period; one-quarter of the fall could be ascribed to a reduction in OM intake and the remainder to the decline in digestibility as such.

3. Intakes were measured during two weeks in late summer and were compared with those measured during two weeks in the spring when the digestibility of the grazed herbage was similar. Intakes of DOM expressed as lb./lb. live-weight0·73 were the lower by about 10% in the late summer, or by from 10 to 20% in terms of DOM available for production when allowance had been made for maintenance requirements. This finding is discussed in relation to practical experience of the feeding value of autumn grass.
The nutrition of the early-weaned calf IV. Ruminal ammonia formation from soluble and insoluble protein sources
Authors: Preston T. R. , Whitelaw F. G. , MacLeod N. A.
Published: September 2010

1. Rumen-ammonia concentration, pH of rumen liquor and blood-urea concentration have been measured at intervals after feeding in six calves given diets containing ‘soluble’ groundnut meal, ‘soluble’ herring meal or ‘insoluble’ herring meal as the major protein source.

2. There were no significant differences between diets in any of the measurements examined. A difference approaching significance was, however, observed between ‘soluble’ herring meal and the other diets in the direction and extent of the change in rumen-ammonia concentration during the first hour after feeding.

3. On all diets, pH of rumen liquor fell to a value in the region of 5·5 immediately after feeding and increased gradually to around 6·5 during the following 8 hr. Rumen-ammonia concentrations were at all times very low.

4. There was no significant residual correlation between changes in blood-urea concentration and the corresponding changes in rumen-ammonia concentration.

5. Rumen-ammonia concentration increased markedly on the ‘soluble’ herring meal diet when the nitrogen intake of the animals was increased by 50%; under similar conditions, only slight increases in this measurement were observed on the other diets.

6. Thesefindingsare discussed in relation to the efficiency of utilisation of dietary nitrogen.
The nutrition of the early-weaned calf V. The effect of protein quality, antibiotics and level of feeding on growth and feed conversion
Authors: Whitelaw F. G. , Preston T. R. , MacLeod N. A.
Published: September 2010

1. A 2×2×2 factorial experiment was carried out with 8 blocks of 8 early-weaned Friesian male calves on the 8 treatment combinations of the following factors: (A) groundnut meal versus white-fish meal as the major protein source; (B) presence versus absence of antibiotic and (C) restricted versus ad lib. feeding. The experiment was conducted over the live-weight range 55–90 kg.

2. The inclusion of fish meal rather than groundnut meal in the diet resulted in highly significant increases in both rate of gain and feed conversion efficiency (P < 0·001). This effect was most apparent at the higher level of feed intake.

3. The addition of antibiotic to the diet increased rate of gain (P < 0·001) and improved feed conversion ratio (P <0·01). Feed intake was increased slightly but non-significantly (P <0.1) on the ad lib. feeding level as a result of antibiotic supplementation.

4. Feed conversion ratio was lower and feed intake and rate of gain were higher on ad lib. than on restricted feed (P < 0·001 in each instance).

5. There was a significant (P < 0·05) level of feeding × antibiotic interaction, indicating that the difference between restricted and ad lib. feeding was greater in the presence than in the absence of antibiotic. No other significant interactions were observed.

6. The use of fish meal in preference to groundnut meal is shown to be justified on economic grounds.
The effect of different levels of management on the assessment of differences between varieties of chickens. II. Egg production, mortality and egg weight
Authors: Bowman J. C. , Powell J. C.
Published: September 2010

1. The data relating to 16 multi-location trials involving several varieties of egg-laying chickens per trial have been analysed to obtain estimates of variety × location (genotype-environment) interactions for rearing and laying mortality, hen-month and hen-housed egg production and 32-week egg weight. Significant interactions were found in about a third of the trials for all five traits though in only two cases did the interaction variance account for more than 20% of the total variance.

2. Genetic correlations for varieties between locations have been calculated as 0·49 for rearing mortality, 0·50 for laying mortality, 0·72 for hen-month production, 0·76 for hen-housed production and 0·91 for egg weight. These are in close agreement with previous published estimates.

3. The between-and within-variety components of variance have been calculated for each trait on each location separately. The regressions within trials and pooled values of the components on the mean level of all varieties on the location have been calculated. For hen-month production the pooled regres-son of the within-variety component on mean was negative, whilst for all other traits the pooled regressions were positive. The pooled regressions of the between-variety components on mean were all positive. It is suggested that this information indicates that comparison of varieties for single traits should be carried out on locations favourable for maximum expression of the trait. The difficulties which variety comparisons, for several traits having different optimum management regimes, would cause and the need for a more intensive investigation of the conditions conducive to genotype-environment interactions are stressed.
The influence of processing and of certain crude enzyme preparations on the utilisation of cereals by pigs
Authors: Burnett G. S. , Neil E. L.
Published: September 2010

1. Three group feeding trials and two individual feeding experiments, involving a total of 202 pigs from 8 to 10 weeks of age to bacon weight, were conducted to determine the effect of processing (steaming, followed by rolling and grinding) of maize and barley on pig performance. The effect of supplementation of raw and processed cereal diets with two crude enzyme preparations was also studied.

2. Processing of maize or barley had no significant effects on rate of growth or efficiency of food utilisation in pigs fed on diets containing a proportion of bran and pollard, or of pigs fed on diets in which maize or barley constituted the entire cereal portion.

3. Neither enzyme preparation affected pig performance.

4. The growth rate and efficiency of food utilisation of pigs given diets high in maize were significantly better than for those given diets high in barley.
Counting dead spermatozoa in frozen semen
Authors: Buttle H. R. L. , Hancock J. L. , Purser A. F.
Published: September 2010

Three methods were used to make differential counts of living and dead bull spermatozoa in samples of frozen semen in an egg-yolk citrate medium containing glycerol.

With two methods (‘phase’ and ‘nigrosin’ methods) dead spermatozoa were identified by their altered structure. With a third method (nigrosineosin) dead spermatozoa were identified by their staining affinity. With the phase method spermatozoa were immobilised by treatment with approximately M/40 sodium fluoride and were examined by phase-contrast microscopy in unfixed wet preparations. With the other two methods the spermatozoa were examined in smears stained either with nigrosin alone (nigrosin method) or with nigrosin and eosin (nigrosin-eosin method).

Analysis of variance of the results of a factorial experiment involving fluoride-treated and untreated samples from 6 bulls with the three methods showed that differences between semen samples contributed 66% of the variation. A defect of the phase method was that the variance between counts was greater than the theoretically expected value.

All spermatozoa in nigrosin-eosin stained preparations were stained with eosin within a few days of the smears being made, so that living and dead spermatozoa could not be distinguished by their differing affinities for eosin. Repeat counts on nigrosin-stained preparations did not differ significantly from counts made several days previously. Sodium fluoride in the concentration used here (M/40) tended to reduce the percentage of dead spermatozoa.
The influence of the level of feeding of suckled pigs on subsequent performance during fattening
Authors: Vanschoubroek F. X. , De Wilde R. O. , Van Spaendonck R. L.
Published: September 2010

Four litters each containing six female pigs were used to compare the influence of the level of feeding of suckled pigs on subsequent weight gain and efficiency of feed conversion, and on carcass quality and ham composition.

The high level pigs always remained on their dam until weaning at 56 days of age and had free access to a starter ration from the beginning of the 4th week of age. From 7 days of age until weaning the low plane pigs were removed from their dam for 12 hours per day and had no access to starter ration during this time. After weaning the pigs were fed ad libitum on dry feed.

It was found that live-weight gain and feed conversion efficiency during fattening were increased by lowering the feed intake of pigs in the first weeks of life. There were no statistically significant differences between the different butcher's joints of the two groups. Although the differences were statistically non-significant, the ham of the low level pigs had a higher protein content (P = 0·06), a higher water content (P = 0·10), a lower fat content (P = 0·07) and a lower energy content (P = 0·12).
Selection in dual purpose cattle populations: defining the breeding objective
Authors: McClintock A. E. , Cunningham E. P.
Published: September 2010

The selection objective in choosing dual-purpose bulls for use in artificial insemination should be the economic benefit conferred on the population with each insemination. The value of a unit of genetic superiority in the bull for a beef or a dairy trait, as realized through one insemination, depends on two factors—the economic value per unit of superiority and the number of times that superiority is expressed. The economic values are easily established. A standard unit of expression for a trait is defined to be one progeny expression in the year in which the insemination is carried out. A method is developed for summarizing the total genetic consequences of an insemination in these standard units. It takes account of the timing of the insemination, the number of years over which the evaluation is carried out, a discount factor, the dilution of the bull's genotype in his descendants, the female replacement rate, the calf survival rate, and the probability that a surviving calf becomes a dairy cow. The method is independent of the full testing procedures, the intensity of selection, and the level of bull usage. It applies, equally, to selection of bulls for general use and for use in planned matings to produce young sires for testing.
The retention of cold acclimatization in sheep
Authors: Slee J.
Published: September 2010

Shorn Blackface sheep were acclimatized to cold by acute or chronic exposures. Acclimatization caused increased resistance to body cooling (IRC) during acute exposure and elevated heart rates at thermoneutrality (28°C). The length of time these effects were retained during subsequent periods at thermoneutrality was monitored.The effect of moderate heat stress (36°C) on previous cold acclimatization was also measured in Blackface and Merino sheep.

Conclusions were:

1. IRC resulted from previous exposure to chronic cold or acute cold. IRC induced by chronic cold began to decay after 2 weeks at thermoneutrality. IRC induced by one acute exposure was maximal 2 weeks after exposure and had disappeared by 8 weeks. IRC induced by two acute exposures combined with chronic cold showed little decrease even after 8 weeks at thermoneutrality.

2. Merino sheep showed 50% lower initial cold resistance and smaller IRC following acclimatization than equivalent Blackfaces.

3. Heat stress for 10 days after cold acclimatization had no effect on IRC in Blackfaces or Merinos.

4. Heart rates measured at 28°C were increased by 20 to 50% following acute and chronic cold exposure. After 3 days at thermoneutrality about 70% of the increase remained; but after 8 days almost all the increase had disappeared.

5. Two components of cold acclimatization were distinguished:

(i) Increased resistance to body cooling probably caused by an enhanced peak metabolic rate capability.

(ii) Increased resting metabolic rate evidenced by high heart rates. After the cessation of cold treatment the rates of decay of these two components were different.
Studies on the nutritive value of the diet selected by grazing sheep VII. A note on hand plucking as a technique for estimating dietary composition
Authors: Langlands J. P.
Published: September 2010

The digestibility and N contents of samples collected by oesophageally-fistulated sheep and by hand plucking were compared. Hand plucking overestimated nutritive value at high levels of digestibility and N content, and underestimated nutritive value when this was low. The differences between fistula and hand-plucked samples varied between pastures. Precision was increased when samples were combined between operators.
Urea as a protein source for ewes with twin lambs in late pregnancy and early lactation
Authors: Parkins J. J. , Fraser J. , Ritchie N. S. , Hemingway R. G.
Published: September 2010

In three experiments housed Greyface (Border Leicester × Scottish Blackface) ewes of mean live weight 68 kg received 0·91 kg hay plus 0·91 kg molassed sugar beet pulp daily during the second half of pregnancy and in the first 3 weeks of lactation. Comparisons were made with additions of crude protein given as urea or groundnut cake either during the whole period or only during early lactation. In one experiment, increasing the daily intake of digestible crude protein from 88 to about 140 g had no effect on the weight of the lamb at birth or at 3 weeks. In the other two experiments, in which the increases were from 58·70 g to 131·161 g or from 80 to about 125 g digestible crude protein per day there were highly significant increases in the weight of the lamb at birth (+0·43 and +0·31 kg) and 3 weeks (+1·44 and +1·46 kg). Introduction of either urea or groundnut cake to the diet on the day after lambing significantly increased the the 3-week weights of the lambs by amounts which were comparable to those found when urea had also been given during pregnancy. Supplementation with either urea or groundnut cake did not significantly increase ewe live weight.

Concentrations of urea in the blood of the ewes were highly significantly increased by either urea or groundnut supplementation. There were indications that a concentration below 10 mg/100 ml in the blood of the ewes in late pregnancy or early lactation was associated with a reduction in lamb growth rates.
Digestibility by ponies of oat straw treated with anhydrous ammonia
Authors: Slagsvold P. , Hintz H. F. , Schryver H. F.
Published: September 2010

The digestibility of oat straw treated with anhydrous ammonia was studied in four Shetland-type ponies in a 4×4 Latin square experiment. The experimental diets which contained soya bean oil meal, corn, sugarcane molasses, and 65% straw were: (1) straw treated with anhydrous ammonia, (2) untreated straw, (3) untreated straw plus urea, (4) untreated straw plus soya bean oil meal. Digestibility of the dry matter was 15% greater (P<0·01) and digestibility of cellulose 28% greater (P<0·01) in diets containing ammonia-treated straw than in those containing untreated straw. Ammonia treatment increased the nitrogen content of the straw by 50%, and nitrogen intake was 18% greater when the ponies were fed diet 1 than when fed diet 2. The nitrogen of the treated straw was utilized as efficiently as the nitrogen of the diet containing untreated straw supplemented with soya bean oil meal. However, the amount of nitrogen provided by the diet of ammonia-treated straw was not sufficient for nitrogen balance in the ponies. Ammonia treatment of oat straw did not affect the utilization of Ca, P, or Mg.
The utilization by lambs of the energy and protein in dried pelleted grass treated with formaldehyde
Authors: Thomson D. J. , Cammell S. B.
Published: September 2010

A primary growth crop of perennial ryegrass (cv. S24), containing 17% crude protein and 9·9 MJ metabolizable energy/kg dry matter, was artificially dried, ground through a 3·0 mm screen and pelleted either without further treatment (C), or after the application of formaldehyde (T) at a rate of 1 g/100 g crude protein. The C and T diets were each fed to 20 lambs for 77 days. Diets C and T were given ad libitum and at three lower planes of nutrition. Similar amounts of dry matter, nitrogen and digestible energy were consumed at each of the four planes of nutrition by lambs fed diets C and T. Carcass energy, fat and protein retention, and total body energy retention were measured by the comparative slaughter technique and did not differ between the diets (P> 0·05). Metabolizable energy intake was calculated from digestible energy intake using the factor 0·81. The efficiency of utilization of the metabolizable energy for growth and fattening (kf) and the net energy value were calculated by linear regression analysis from the total body energy retention, the calculated metabolizable energy intake and dry-matter intake data scaled to M0·75. They did not differ between the diets (P > 0·05), and were 0·370 (C) and 0·431 (T) for kf, and 2·09 (C) and 1·97 MJ/kg dry matter (T) for net energy.
The optimum level of protein in the supplement for dairy cows with access to grass silage
Authors: Gordon F. J. , McMurray C. H.
Published: September 2010

Grass silage with a dry-matter content of 19·4% and containing 16·7% crude protein was offered ad libitum to 42 first lactation British Friesian cows during the first 75 days post-calving. In addition the animals received supplementary concentrates containing either 10·3, 13·6, 17·3, 21·1, 25·2 or 30·3% crude protein on a fresh weight basis, with extracted soya bean meal being used as the main protein source. All concentrates were offered at an equal level of 8·0 kg per day. The relationship between milk yield and protein content of the supplement was curvilinear and was described by the following equation:

Y= 8·95+ 1·0×–0·0205×

where Y = milk yield per day in kg, and × = percentage protein in the supplement. This equation indicated that maximum milk yield was obtained with a concentrate containing 24·4 % protein on a fresh weight basis. The protein content of the milk was also curvilinearly affected by the level of protein in the supplement, and it was calculated that maximum milk protein (nitrogen × 6·38) would be obtained with a supplement containing 23·9% protein. Plasma blood urea levels increased linearly with increasing protein intake. The effects on live-weight change and blood components were also recorded.
Growth of store lambs on cereal-based diets with protein or urea
Authors: Ørskov E. R. , Grubb D. A.
Published: September 2010

Two experiments were conducted on the fattening of 8- to 10-month-old lambs weighing about 40 to 55 kg live weight, using diets based on whole barley sprayed with a solution of urea and minerals or supplemented with a pelleted fish-protein concentrate.

In one experiment the lambs had been adapted to indoor conditions but had been subjected to low levels of nutrition. In the other experiment the lambs were not previously adapted to indoor conditions. The lambs in the first experiment suffered no growth check while the lambs taken inside did not gain in weight for 2 to 3 weeks. In both experiments the lambs showed a short term or compensatory growth response to protein after which there were no differences between lambs receiving fish-protein supplements or urea-fortified grain.

The results are discussed in relation to response to protein and urea and the method of incorporating urea and minerals as solubles in whole grain is discussed.
Late pregnancy ewe feeding and lamb performance in early life. 2. Factors associated with perinatal lamb mortality
Authors: Khalaf A. M. , Doxey D. L. , Baxter J. T. , Black W. J. M. , FitzSimons J. , Ferguson J. A.
Published: September 2010

Some factors affecting perinatal lamb mortality were studied with 63 Finn × Dorset Horn ewes and 85 Scottish Half bred and Greyface ewes, having an average litter size of 2·26. Total perinatal lamb mortality averaged 29 % of which 44% were stillborn, 1 % attributed to dystocia, 35 % died between birth and 48 h of age, 14 % from 48 h to 10 days, and 5 % after 10 days.

For the Finn × Dorset ewes, the 41 viable twin lambs weighed at birth 3·47 kg and 12 twin lambs which did not survive weighed 2·51 kg. Triplet weights were: viable 2·98 kg (34 lambs) and nonsurviving 2·00 kg (14). Quadruplet weights were: viable 2·79 kg (12) and non-surviving 1·90 kg (16). Quintuplet and sextuplet weights were: viable 2·45 kg (2) and non-surviving 1·35 kg (14).

In the aggregated Halfbred and Greyface breeds, viable twin lambs weighed 4·5 kg at birth (91) and non-surviving 3·64 kg (11). Viable triplets weighed 3·77 kg (23) and non-surviving 2·68 kg (16).

Serum gamma-globulin and total serum protein values were lower in the lambs which failed to survive, and this was particularly marked with triplets. Fractionating the gamma-globulins (IgG) indicated that IgGi was particularly low in non-viable lambs.

Litter size, lamb birth weight, and colostrum intake by the lamb had important effects on perinatal lamb mortality.
A note on consumer acceptability of liver from pigs fed a sugar solution immediately prior to slaughter
Authors: Fernandes T. H. , Smith W. C.
Published: September 2010

In a consumer test involving 108 households, liver from pigs fed a sucrose solution in lairage overnight prior to slaughter was preferred on its appearance to that from pigs which had received water only during the resting period. Highly significant preferences were shown for fried and casseroled sugar-fed liver in relation to tenderness and juiciness but not flavour. When all eating characteristics were taken into consideration participants were equally divided in their preferences for ‘sugar-fed’ and normal liver.
A note on the effect of temperature on the performance of early-weaned pigs
Authors: McCracken K. J. , Caldwell B. J. , Walker N.
Published: September 2010

Two temperature regimes were compared in relation to the growth and feed conversion ratio of groups of cage-reared pigs between 10 and 38 days of age. The treatments were: 27°C at 10 days reducing by 1°C every 4 days to 20°C at 38 days; and 27°C at 10 days reducing by 1°C daily to 20°C at 17 days and then remaining constant. Twelve replicates using 244 pigs were completed, the group size varying between 9 and 12 pigs. The mean growth rates on the two temperature regimes were respectively 234 and 243 g/day, and in both cases feed conversion ratio (kg DM/kg gain) averaged 1·03. It is concluded that temperatures lower than those currently recommended for pigs weaned at 14 to 16 days into controlled-environment houses would support satisfactory performance with direct savings in heating costs under winter conditions.
A note on the use of sodium hydroxide treated straw pellets in diets for growing rabbits
Authors: de Blas J. C. , Merino Yolanda , Fraga Maria J. , Gálvez J. F.
Published: September 2010

The effects of the inclusion of increasing quantities of cereal straw treated with sodium hydroxide in the diet of rabbits weie studied on 68 animals, both males and females, of the Spanish Giant and New Zealand × Spanish Giant breeds, weaned at different weights. The nitrogen and fibre digestibilities, the overall growth rate (from weaning to 2·25 kg) and the partial growth rate (from weaning to 2 weeks after weaning) increased linearly, while the feed conversion rate decreased when the content of treated straw in the feed was raised. The overall growth rate for males was significantly higher (P < 0·001) and feed conversion rate lower (P < 0·01) than for females. The crossbred animals had a significantly higher overall (P < 0·001) and partial (P < 0·05) growth rate. As weaning weight increased, overall (P < 0·001) and partial (P < 0·05) growth rate also increased, whereas the dressing percentage of the carcass decreased significantly (P < 0·01).
The response of spring-calving cows to a high level of protein in the supplement given with grass silage during early lactation
Authors: Gordon F. J.
Published: September 2010

A randomized block experiment, using 30 British Friesian cows, was used to assess the effects of offering supplements containing 172 and 234 g crude protein per kg dry matter in addition to grass silage which had a very high digestible organic matter in the dry matter of 769 g/kg. The animals, which had a mean calving date of 1 February, were blocked according to calving date and lactation number and allocated at random within each block to the two treatments. The treatments were applied from day 8 of lactation until the animals went to pasture on 13 April and both supplements were offered at the same rate of 7·6 kg per day. The total yields of milk produced during the experimental period were 1626 and 1650 ±38·4 kg and the mean daily yields during the final week were 24·8 and 25·6 ± 0·58kg for the medium and high protein supplements respectively. The mean live weights for the two groups were 524 and 544 ± 5·5 kg, and body condition score 2·9 and 3·3 ± 0·34 for the medium and high protein supplements respectively at the end of the treatment period. No significant treatment effects on milk composition were recorded at any stage during the experiment. Analysis of blood samples taken during the final week of the experiment showed plasma urea levels, at 220 and 290± 18 mg/1 for the medium and high protein supplements respectively, to be significantly different.