bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractScarce 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

AbstractSeventy-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

AbstractAn 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.
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

SUMMARY1. 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

SUMMARY1. 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

SUMMARY1. 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

SUMMARY1. 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

SUMMARY1. 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

SUMMARYThree 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

SUMMARYFour 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

SUMMARYThe 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

SUMMARYShorn 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

SUMMARYThe 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.