bluuebunny/crossref_metadata_2025_split huggingface dataset:
The assessment of a crop husbandry technique in terms of animal production
Authors: Blaxter K. L. , Wilson R. S. 
Published: September 2010

SUMMARY1. The energy value of three hays cut at three stages of maturity was. measured by calorimetric methods and, in addition, the amounts of the hays consumed voluntarily by sheep were measured. Voluntary intake was alsa measured when 200, 500, 800 and 1,200 g. of pelleted concentrates were given.2. The metabolisable energy values of the three hays measured at the-maintenance level were 2·45, 2·26 and 2·16 kcal./g. for cuts 1, 2 and 3-respectively (cut 1 being the earliest). The net energy values for fat production were 0·96, 0·85 and 0·68 kcal./g. respectively.3. The apparent digestibility of the hays fell with increasing intake, but supplementation with concentrates increased their apparent digestibility.4. The voluntary intake of the hays given as the sole food was 70, 62 and 57 g./kg. W0·73 for the three cuts, respectively. When concentrates were given in increasing amounts, the intake of cuts 2 and 3 increased to maxima of 65 g. and 64 g./kg. W0·73 respectively and thereafter declined. With cut 1, intake of hay declined even with the smallest intake of concentrates. Voluntary intake of the hays was maximal when the protein content of the whole ration was 8·5%.5. When no supplement was given the digested energy per sheep per day supplied by cut 1 was 64% greater than that supplied by cut 3. When 800 g. concentrates were given, however, the ration including the early cut of hay provided only 2% more energy than that including the late cut.6. It is shown that if hay were given as the sole food cut 3, which produced 57% more weight of crop per acre, would provide 38% more metabolisable energy/acre and 11% more net energy (starch equivalent)/acre than would cut 1. The late cut would also enable 92% more sheep to be kept feeding to maximal appetite on an acre of produce. However, the total live-weight gain per acre would be only 25% of that obtained with thefirstcut.7. Comparable calculations have been made for the experiments in which concentrates were given. It is shown that here too optimal times of cutting can only be assessed in terms of estimates of animal production.
Inbreeding arising through artificial insemination and natural service in Welsh black cattle
Authors: Watson J. H. 
Published: September 2010

SUMMARYCurrent rates of inbreeding due to A.I. and natural service are estimated in Pedigree Welsh Black cattle.Since 1948, 27 sires have been used in A.I., 16 of which have a common male ancestor. Four sire-son pairs and two pairs and one trio of half-brothers have been in recent use. Two-thirds of the bulls and heifers bred by A.I. and registered in 1960 were sired by 4 bulls. Since 1954 progeny of two A.I. sires who are father and son, were preferred for registration.Pedigree analysis of a sample of 128 bulls showed that those bred by A.I. were, on average, 2·80% inbred, compared with 2·32% for those from natural matings. In a sample of 166 heifers corresponding values were 0·82% and 1·17%.One herd, through natural service, contributed 12% of the genes of a sample of bulls and heifers. Four other herds were outstanding for the number of males they provided. The average inbreeding of their young, registered bulls was estimated to be 7·04%.The widespread use of the descendents of one bull, both in A.I. and natural service, led to 94 cases of inbreeding in the third and fourth ancestral generations of the pedigrees of animals in the sample.It is concluded that the short term consequences of using a small number of bulls in A.I. measured in terms of inbreeding, are no different from those in natural service and that inbreeding depression in traits of commercial importance would be undetectable.
Heritability of milk yield at different environmental levels
Authors: VanVleck L. D. , Bradford G. E. 
Published: September 2010

Milk production records from 5740 first lactation Holstein-Friesian daughter-dam pairs were studied to determine if heritability was related to herd production level. Heritability from daughter-dam regression was essentially constant at 10 environmental levels based on either the dam's or daughter's herdmate deviation from season average yield. The heritability estimate over all levels of yield was 0·43 (with standard error 0·03) which is higher than most estimates. Estimates of heritability from paternal half-sib correlations for four environmental levels and based on data from 2568 daughters of A.I. sires generally increased as the herd production level increased. The highest half-sib estimate was 0·42 and the lowest 0·17. Daughter-dam estimates from the same data were essentially constant over the four herd levels.Total variation increased as herd level increased, in agreement with previous reports.Heritability was found not to differ between seasons of calving.
Effects of various low protein diets on the distribution of ruminal nitrogen and on the nitrogen required for maintenance of African sheep
Authors: Elliott R. C. , Topps J. H. 
Published: September 2010

1. Four groups of diets made up with differing proportions of roughage and concentrates were each givenad lib. to 4 Blackhead Persian wether sheep. The four diets in each group contained approximately 4, 6, 8 and 10% crude protein. The distribution of nitrogen in the rumen at various times after feeding and the nitrogen balance of the sheep were measured.2. Total N and ammoniacal N content of the rumen liquor were both closely related to the N content of the diet. Diurnal changes in the concentrations of these components were most marked with the diets which had the highest concentration of protein, and consisted of rapid increases after feeding followed by declines later in the day. Each group of diets produced characteristic patterns of change and these changes appeared to be related to the proportion of concentrates in the diet.3. With sheep given poorly digested veldt grass, very low in protein, levels of ammonia in the rumen were unusually high. This effect was thought t o be due to the recycling of urea and its conversion to ammonia in the rumen.4. The amounts of digestible N required by the sheep for N equilibrium differed between groups of diets. High apparent requirements of digestible N were associated with relatively high ruminal ammonia levels, but the latter were not considered to be the cause of high requirements.5. On all groups of diets, sheep were in N equilibrium only when their intakes of total digestible nutrients (TDN) were adequate for maintenance. This indicates that the protein requirement for maintenance was a function of protein content and TDN content of the diet and the effect of these factors on voluntary intake of TDN.
Long- and short-term effects on intake of pelleting a roughage for sheep
Authors: Greenhalgh J. F. D. , Reid G. W. 
Published: September 2010

SUMMARY1. Four groups of eight castrated male lambs, weighing initially about 37 kg, were fed ad libitum for 18 weeks on: C, chopped dried grass throughout; P, pelleted grass throughout; C/P (or P/C), the two forms alternated every 3 weeks; or C + P, both forms on offer.2. Daily dry-matter intake (g/kg W0·75) was 58·2 for treatment C and 814 for treatment P; thus the long-term difference in intake was 40%. However, in the alternated sheep, dry-matter intake was 53·6 g/kg W0·75 for chopped grass and 86·5 g for pelleted; this short-term difference (61%) was significantly greater than the long-term difference. Dry-matter intake for treatment C+P was 84·9 g/kg W0·75; after the first week, chopped grass comprised only 10% of this. Dry-matter digestibility coefficients (%) were: C, 740; P, 61·4 and C+P, 62·0.3. The sheep were killed in week 19 and the dimensions of digestive organs and their contents were adjusted to an animal of 50 kg empty body weight. The weight of the reticulo-rumen was greater for C (1·30 kg) than for P (0·94) or C+ P (1·05), C/P and P/C being inter-mediate (1·15). The water-filled volume of the rumen was proportional to weight, except that C/P (alternated sheep finishing on pelleted grass) had low volumes. Reticulo-rumen fill was greater for C (7·28 kg) than for P (3·97) or C+ P (4·53), P/C (5·90) and C/P (4·34) being intermediate. There were no other significant differences in organs or contents.4. Gains in empty-body weight (g/day) were: C, 112; P, 181; C/P and P/C, 126; C + P, 195.
The economics of calving intervals
Authors: James A. D. , Esslemont R. J. 
Published: September 2010

ABSTRACTA computerized mathematical model was used to test the economic effect of changing calving intervals under typical high-yielding (63701 per 305 days for mature cows) herd conditions at 1976 prices. The effect of month of first calving was also tested in a herd where four lactations are assumed to follow at equal calving intervals.Under the prescribed conditions, cows should calve at 320-day to 360-day intervals (with two exceptions) to maximize the annual margins over concentrates, but the month of the initial calving affects the absolute level of margins over concentrates markedly (maximum £382·10 for 365-day interval for November calving, minimum £318·10 for April). This means that complete knowledge of the main input-output factors is required before recommendations can be made for an individual cow. The change in margin over concentrates for each day's delay in conception varies widely, with rates of loss as high as £1·80 per day's delay occurring.
The influence of restricted physical contact with pigs during rearing on the sexual behaviour of the male domestic pig
Authors: Hemsworth P. H. , Beilharz R. G. 
Published: September 2010

ABSTRACTThree groups of five male pigs (boars) were reared from an early age under various social conditions. The sexual and social behaviour of the boars was studied from 31 to 56 weeks of age. Boars individually reared from 3 to 12 weeks of age in adjacent wire-mesh pens had similar copulatory performance to that of group-reared boars. However, an apparently important component of courting behaviour, ‘nosing activity’, was significantly reduced (P<0·05) amongst those boars individually reared from 3 weeks of age in adjacent wire-mesh pens. Social behaviour appeared to be unaffected by the rearing treatment.
Effect of flaked maize in diets for early-weaned pigs on performance to 6 weeks of age
Authors: McCracken K. J. , Eddie S. M. , Walker N. 
Published: September 2010

ABSTRACTFour experiments were conducted to study the performance of pigs weaned at 10 days on to diets containing different amounts of flaked maize.Digestibilities of dry matter and energy of flaked maize were found to be 0·87 for pigs between 11 and 16 days of age.Starter diets containing 0, 250 or 375 g flaked maize/kg, given from 10 to 35 days, resulted in growth rates of 254, 254 and 213 g/day respectively and the reduction with the high level of maize was significant (P< 0·001). Feed conversion ratio was unaffected by treatment and averaged 1·08.When the starter diets were replaced at about 24 or 27 days by a cereal-based diet containing 200 g dried skim milk/kg there were no significant differences in performance between 10 days and 10 kg live weight due to starter diet, and growth rates were similar t o those obtained when the starter diets were given to 35 days. However, there was a consistent trend of lower food intakes, poorer feed conversion ratio and, consequently, poorer growth during the immediate post-weaning period on the starter diet containing 375 g flaked maize/kg.
Effects of magnesium supplements on the digestion of forages and milk production of cows with hypomagnesaemia
Authors: Wilson G. F. 
Published: September 2010

ABSTRACT1. Ground forages were digested in vitro in rumen liquor supplemented with four concentrations of magnesium as MgSO4-7H2O (5, 20, 80, 320mg Mg/1) to determine the effects of magnesium on organic matter digestibility. A medium concentration of magnesium (generally 80 mg/1) resulted in optimum digestion although there was a large interaction between forage type and the response to magnesium.2. Supplements of MgSO4-7H2O (2g Mg/day) increased the apparent digestibility of two types of hay fed to sheep, the difference being significant for poor quality hay (P<0·05).3. The milk production of hypomagnesaemic cows given supplementary magnesium either orally, by rectal infusion, or by subcutaneous injection was compared. Plasma magnesium concentrations were increased to a similar and significant extent (P<0·01 ) but a significant increase in milk and fat production occurred only in the orally treated cows (P<0·05).It was concluded that a dietary magnesium deficiency results in reduced rumen fermentation and hence poor production, as well as hypomagnesaemia. It was suggested that the effects on performance of other mineral deficiencies may also be mediated in part through depressions in rumen digestion.
Effect of various light regimes on lamb production by Rambouillet and Suffolk ewes
Authors: Vesely J. A. , Bowden D. M. 
Published: September 2010

ABSTRACTSix production cycles, each of 212 days' duration, were completed with Rambouillet and Suffolk ewes. One group of each breed was maintained under natural light conditions (control) and three groups of each breed were under the influence of various light treatments applied regularly in a rhythmic fashion within each production cycle. Comparison of conception rates between production cycles, breeds, and treatments showed that only in production cycle 2 (mating in June) were the conceptions in control ewes of both breeds significantly lower than those in ewes on altered light treatments. The most meaningful result was the effect of light treatments on prolificacy. Treatment 3 (106 days with 16-h light per day and 106 days with 8-h light per day) gave significantly higher prolificacy than control and treatments 1 (106 days with 8-h light per day starting 65 days before mating) and 2 (42 days with 16-h light per day, then light reduction at 21 min/week for 160 days). Rambouillet and Suffolk control ewes produced annually 179 and 174 lambs per 100 ewes exposed to rams. Corresponding productions were 200 and 197 for treatment 1, 193 and 226 for treatment 2, and 223 and 242 for treatment 3.
Performance of pigs given diets containing different levels of triticale
Authors: Nishimuta J. F. , Sunki G. R. , Rao D. R. 
Published: September 2010

ABSTRACTSixty crossbred female and male castrate pigs were randomly allocated to five treatments in which 0, 20, 40, 60 and 80% of the ground maize in grower and finisher diets was replaced by triticale on an equal weight basis.Pigs receiving the basal maize growing diet (0% tritcale) gained less than pigs fed the triticale diets (P<0·05). Pigs given the diets in which 20% of the maize was replaced by triticale gained significantly more than those given the other diets (P<0·05). Increasing replacement in the grower diets beyond 20% resulted in a linear decrease in consumption and weight gains (P<0·05). Feed conversion was similar for all diets which contained triticale.The basal finisher diet, and the diet with 20% of the maize replaced, promoted better feed consumption and weight gain than the diets in which 40, 60 and 80% of the maize was replaced by triticale during the finishing phase and for the entire 109-day growing-finishing period. Carcass quality grade was higher for pigs fed the basal diet and the diet in which 20% of the maize was replaced by triticale (P<0·05 ) but there were no differences in the other parameters of carcass quality, nor in the composition, cooking quality and organoleptics,. of the longissimus muscle. Fatty acid profiles of the longissimus muscle indicated that palmitic and oleic acids were significantly higher (P<0·05 ) and linoleic and palmitoleic significantly lower (P<;0·05) in pigs given the basal and 20% replacement diets than in pigs given the other diets. The results show that triticale could replace maize partially (up to 20%) in diets for pigs.
A note on the relationship between live weight and the incidence of oestrus in Hereford heifers
Authors: Cohen R. D. H. , Garden D. L. , Langlands J. P. 
Published: September 2010

ABSTRACTThe incidence of oestrus in 603 Hereford heifers with a mean age of 545 days (range 515 to 575) was related to live weight (range 130 to 376 kg). Observations were ranked in order of ascending live weight and the percentage of heifers showing oestrus was calculated for consecutive 10 kg increments in live weight from 130 to 380 kg. The percentage showing oestrus was subjected to the probit transformation (Y, probit units) and was then related to live weight (X, kg):It was predicted that 50% of the heifers showed oestrus at 231 ± 1 kg, and that 5% and 95% showed oestrus at 187 and 280 kg respectively.
Some aspects of the energy and nitrogen metabolism of boars, gilts and barrows given diets containing different concentrations of protein
Authors: Holmes C. W. , Carr J. R. , Pearson G. 
Published: September 2010

ABSTRACTFour diets which varied in crude protein concentration from 140 to 240 g crude protein per kg dry matter were given to gilts in experiment 1, and two diets containing 140 and 200 g crude protein per kg dry matter were given t o boars and barrows in experiment 2. Two levels of feeding were offered in both experiments and energy and nitrogen balances were measured at 30 and 90 kg live weight in both experiments, and also at 50 kg in experiment 1. Nitrogen intake had a small negative influence on energy retention by pigs of all sexes, an effect which was independent of the large positive effect of metabolizable energy intake. The ratio of metabolizable energy concentration to digestible energy concentration decreased in association with increases in crude protein concentration of the diets. The results show that comparisons of feeds on the basis of their digestible energy concentrations would lead to overestimation of the energy values of those containing high protein concentrations. Live weight (or age) and metabolizable energy intake exerted positive influences on the amount of energy retained per kg live-weight gain, whereas nitrogen intake exerted a negative influence. Values for energy retained per kg live-weight gain predicted from multiple regression equations, together with calculated values for maintenance and net efficiency, were used to predict the energy retention and growth rate of pigs in various circumstances.Nitrogen retention increased in association with increases in nitrogen intake for pigs of all sexes at 30 kg live weight; there was also a corresponding increase for boars at 90kg live weight, but not for gilts or barrows at this weight. Boars retained more nitrogen than did barrows at 30 and 90 kg live weight only if given the diet with the higher concentration of protein.Metabolizable energy intake appeared to exert a small positive influence on the nitrogen retention by pigs of all sexes at 90kg live weight; however, it appeared to have no influence on nitrogen retention by pigs at 30kg live weight.
A note on the accuracy of an ultrasonic technique for selecting cattle of different breeds for slaughter at equal fatness
Authors: Kempster A. J. , Owen M. G. 
Published: September 2010

ABSTRACTIn the first phase of the Meat and Livestock Commission's beef breed evaluation programme, cattle were slaughtered at a fixed subcutaneous fat percentage in carcass. Slaughter point was determined from fat areas measured over the m. longissimus at the 10th and 13th ribs by the Scanogram ultrasonic machine.The accuracy of the slaughter procedure was examined using data for 1367 cattle from the first 3 years of the programme. Subcutaneous fat percentage predicted from the ultrasonic measurements was compared with the percentage estimated by visual assessment of carcass fat cover. The s.d. of the difference between the two was 1·65.Data for a subset of 313 cattle were used to examine the relationships between the ultrasonically measured fat areas and actual subcutaneous fat percentage obtained by dissection. The residual s.d. for the prediction of subcutaneous fat within breed and production system was 1-18.The level of accuracy achieved was considered to be satisfactory within the context of the beef breed evaluation programme.
The effect of climatic housing and level of nutrition on the performance of calves
Authors: Williams P. E. V. , Day D. , Raven A. M. , McLean J. A. 
Published: September 2010

ABSTRACTFive hundred and seven British Friesian × Ayrshire bull calves were reared on a once-daily milk replacer feeding system from approximately 6 to 72 days of age in four naturally ventilated, unheated calf houses differing in design and degree of insulation. Environment within the calf houses was monitored each hour. Differences in design and degree of insulation produced small but significant differences in internal house temperature, humidity and air movement which had no measurable effect on calf daily live-weight gains.Calves receiving 0·6 kg/day compared with 0·3 or 0·4 kg/day of milk replacer plus concentrates ad libitum ate less concentrates but had higher daily live-weight gains (0·56 compared with 0·49 kg/day respectively) (P < 0·001). Rations supplying similar amounts of metabolizable energy from varying proportions of milk:concentrate resulted in comparable live-weight gains. Results suggest that calf viability was affected by level of nutrition and that low levels of milk replacer feeding resulted in higher mortality. Naturally ventilated, unheated calf houses were demonstrated to be suitable for rearing calves in south-west Scotland.
The influence of nutrition on reproduction in the ewe 1. Effects on ovulation rate, follicle development and luteinizing hormone release
Authors: Haresign W. 
Published: September 2010

ABSTRACTTwo groups of 15 ewes in store body condition were either given a maintenance level of feeding or a twice-maintenance level (flushed) during the course of one oestrous cycle. Five ewes from each feeding level were slaughtered at 0, 18 or 48 h after the onset of the oestrus at the end of the treatment period and measurements were made of the luteinizing hormone content of their pituitary, the luteinizing hormone concentration in their blood plasma, their ovulation rates, and ovarian follicle numbers and sizes.‘Flushed’ ewes had a significantly higher ovulation rate (260, s.e. 0·24 v. 1·80, s.e. 0·20; P <0·05), although there was no significant difference in either pituitary luteinizing hormone content or plasma luteinizing hormone concentrations at oestrus.Analysis of the patterns of ovarian follicle distribution suggest that flushing ewes for one oestrous cycle might increase ovulation rate by preventing the late atresia of large follicles in the last 30 h before ovulation.
A note on haemoglobin type and reproductive performance of ewes grazing oestrogenic pastures
Authors: Walker S. K. , Obst J. M. , Smith D. H. , Hall G. P. , Flavel P. F. , Ponzoni R. W. 
Published: September 2010

ABSTRACTField data were analysed in an attempt to identify factors contributing to differences between haemoglobin types n i the proportion of ewes lambing per ewe exposed to the ram in flocks grazing oestrogenic pastures. The number of ewes mated and the proportion of ewes failing to conceive to first service per ewe exposed to the ram were analysed. Neither was found to significantly differ between matings of different haemoglobin type. It is concluded that differences in reproductive performance between haemoglobin types could possibly result from differences in embryo survival.