bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimum selection intensity in breeding programmes
Authors: James J. W. 
Published: September 2010

SUMMARYThe present value of future genetic improvement in a closed population is taken to be proportional to the sum of discounted changes in the population mean. It is shown that, if T animals are available for selection and R is the discount rate per generation, the selection intensity which maximizes present value is a function of TR. If TR is greater than 15, under 10% of the population should be selected. It is then shown how T can be chosen to maximize profit if the value of genetic improvement and cost of testing are known. The theory is illustrated by a numerical example.
Selection of extremes
Authors: Abplanalp Hans 
Published: September 2010

SUMMARYA method of selection for two or more traits is investigated, where the selected individuals have to be the highest performing for any one trait, but not necessarily for several traits. The efficiency of selection of extremes is contrasted with the methods of culling levels and tandem selection. It is shown to be superior to culling level selection when the proportion of individuals retained for breeding exceeds 0·5. At higher selection intensities, the effectiveness of selection of extremes falls between that of culling levels and tandem selection.
Effect of winter environment on growth of young beef cattle 1. Effects of exposure during winter to rain or wind and rain combined on performance of 9-month-old Friesian steers fed on two planes of nutrition
Authors: McCarrick R. B. , Drennan M. J. 
Published: September 2010

SUMMARYThree experiments were conducted to compare the performance of 9-month-old Friesian steers wintered in three environments, (a) conventional cattle houses, (b) wind-sheltered roofless sawdust pads and (c) unsheltered roofless sawdust pads. Within each environment animals were fed on two planes of nutrition.In each experiment, winter live-weight gains of animals accommodated on the three winter environments were similar as were weight changes during the subsequent four weeks at grass in Experiments 2 and 3.No interaction on live-weight gain was found between plane of nutrition and winter environment. Health of outwintered animals was good throughout. The response to feeding barley with hay in these experiments (obtained by comparing low-plane with high-plane treatment groups) showed that on average 5·5 kg of barley dry matter were required to produce 1 kg of additional live-weight gain above that obtained from hay fed alone.
The effects of level of feeding during rearing and early pregnancy upon reproduction in young female sheep
Authors: Hamra A. M. , Bryant M. J. 
Published: September 2010

ABSTRACTTwo hundred and forty Suffolk × (Cadzow Improver × Scottish Blackface) female sheep were housed at 4 months of age and average live weight (± s.d.) of 30·6 ± 501 kg, and divided into four equal treatment groups: HH, HL, LH and LL. They were group-fed such that HH and HL sheep were 39·7 ± 5·27 kg, and LH and LL were 35·6 ± 4·64 kg, at puberty, which was recorded in all sheep. There were no differences in average date at puberty.After puberty the sheep were gradually transferred to different levels of feeding by the time of mating with fertile rams at the second oestrus such that HH and LH were group-fed 1·50, and HL and LL 0·75 of maintenance requirement. The sheep were slaughtered at return or 25 ± 3 days after mating.The proportion of sheep with live embryos was 0·48,0·40,0·50 and 0·41 for HH, HL, LH and LL groups respectively (NS). Ova wastage was 0·59, 0·68, 0·51 and 0·59 for the treatments, with statistically significant differences in losses between treatments in sheep with two corpora lutea (P<0·05). Ovulation rate also differed between treatments (HH > HL, P < 0·01; HH > LH and LL, P < 0·05). Differences occurred between treatments in the proportion of multiple cycles between first and second oestrus (P<0·05), and HL sheep had a greater proportion of sheep failing to return to service but without embryos (HH>HL, P<0·05). The pooled results showed that pregnant sheep were heavier at 4 months of age (P < 0·05), but not at mating, than non-pregnant sheep. Sheep with two corpora lutea were more likely to be pregnant than sheep with one corpus luteum (P < 0·05).
The effect of pattern of concentrate allocation on milk production from autumn-calving heifers
Authors: Gordon F. J. 
Published: September 2010

ABSTRACTForty-four British Friesian, first-lactation heifers were used in a randomized block experiment over a 2-year period to examine the effects of two patterns of concentrate allocation during the post-calving, indoor feeding period. The animals, mean calving date 17 October (s.d. 15 days), were offered concentrates either on a high-low system consisting of 80kg/day for the first 90 days of lactation and thereafter 5-4kg/day, or on a uniform system in which 6-8 kg/day was offered from calving until going to pasture (mean of 182 days). In addition, all animals received access ad libitum to grass silage, with a mean dry-matter content and digestible organic matter in the dry matter value of 218 and 679g/kg respectively. During the 1st year all 22 animals were housed as a single group, but in the 2nd year the animals were housed in individual stalls and silage intakes recorded for all replicates. In each year all animals grazed as a single group at pasture without supplementary concentrates.Total concentrates consumed were 1163 and 1187 (s.e. 19·4)kg for the high-low and uniform treatments respectively. Although the animals on the high-low treatment reached a higher peak milk yield, there were no significant differences in milk yield over the winter period, 3257 and 3311 (s.e. 41·5) kg, or total lactation, 4862 and 4886 (s.e. 80·6)kg, for the high-low and uniform treatments respectively. The animals on the high-low treatment, however, were significantly lighter in body weight at the end of the winter but there was no difference between treatments at the end of lactation. Milk composition data are also presented.
A study of body weight from birth to 1 year of age in European-zebu crossbred cattle in Ethiopia
Authors: Kebede B. , Galal E. S. E. 
Published: September 2010

ABSTRACTBody weights at birth, 90 days, 180 days and 1 year of age were analysed in 620 calves, the offspring of sires of the Friesian, Jersey and Simmental breeds, and of dams of three indigenous zebu breeds, namely Barka, Boran and Horro, at four diverse locations in Ethiopia.Breed of sire, breed of dam and location all significantly affected weight. Progeny of Friesian and Simmental sires were similar in weight but both were heavier than the progeny of Jersey sires, their weight being, respectively, 25·0,24·9 and 21·2 kg at birth; 88·0, 84·6 and 74·9 kg at 90 days; 151·7, 150·6 and 135·4 kg at weaning at 180 days; and 220·6,224·8 and 193·3 kg at 365 days. Barka crosses were heaviest and Horro lightest. Mean weight for progeny from Barka, Boran and Horro dams was, respectively, 24·0, 24·6 and 22·5 kg at birth; 85·2, 83·8 and 78·5 kg at 90 days; 149·6, 148·0 and 140·1 kg at 180 days; and 233·7, 208·1 and 196/9 kg at 365 days. Dam breed × location interaction was significant except at birth, and sire breed × dam breed and sire breed × location interaction were significant at 90 days of age. In a comparison of Friesian and Simmental, the Friesian sires interacted relatively more favourably with the Barka dams, and the Simmental with the Boran. The Jersey was also relatively better with the Boran crosses, compared with either the Barka or the Horro crosses. By 1 year of age Jersey crosses were at a relative (but insignificant) advantage in body weight at the hottest location.
An evaluation of red clover silage for beef production
Authors: Steen R. W. J. , McIlmoyle W. A. 
Published: September 2010

ABSTRACTTwo experiments have been conducted to compare wilted, formic acid-treated red clover and unwilted, formic acid-treated grass silages for beef production, and to examine the effects of digestibility of red clover and level of concentrate supplementation on food intake and animal performance.In experiment 1, 12 groups of four British Friesian steers (initial live weight 229 kg) were given red clover silages of high and low dry-matter digestibility (0·70 and 0·60 respectively) and grass silage (0·71) ad libitum for a period of 11 weeks. Silage dry-matter intake and live-weight gain for the steers given red clover of high digestibility, red clover of low digestibility and grass silages were 7·75, 0·89; 6·91, 0·69; and 5·59, 0·59 kg/day respectively.In experiment 2, 12 groups of four British Friesian steers (initial live weight 332 kg) were given red clover silage with a dry-matter digestibility of 0·63 and grass silage with a value of 0·76 ad libitum, either unsupplemented or supplemented, with 2 kg/day of fortified barley per head for a period of 19 weeks. Silage dry-matter intake, live-weight gain and carcass gain were 8·52, 0·63, 0·32 and 6·98, 0·78, 0·43 kg/day for the unsupplemented and supplemented red clover silage treatments, and 6·82, 0·59, 0·31 and 5·75, 0·75, 0·44 kg/day for the unsupplemented and supplemented grass silage treatments respectively. The performance of the cattle offered red clover silage was similar to that of cattle offered grass silage of 0·12 higher digestibility, largely as the result of higher dry matter intakes achieved on red clover silage.
The effect of various factors on the efficacy of tylosin as a growth promoter in clinically healthy pigs
Authors: Jones P. W. , Tarrant M. E. 
Published: September 2010

ABSTRACTNineteen field trials were conducted in eight 1 uropean countries to examine the effects of tylosin, administered in the food at a level of 20mg/kg to healthy pigs under good management conditions. Average daily gain and food conversion ratio were improved by 33 g and 0·17 respectively over untreated control animals, with no change in average daily food consumption. These improvements in growth performance were similar in the grower and finisher phases, and the response to tylosin was not affected by sex, initial weight or year. Absolute responses in average daily gain and efficiency of food utilization were constant, whatever the level of performance in the controls.
Plasma concentrations of progesterone, oestradiol-17β and luteinizing hormone in relation to repeat breeding in buffalo (Bubalus bubalis)
Authors: Arora R. C. , Pandey R. S. 
Published: September 2010

ABSTRACTProgesterone, oestradiol-I7β and luleinizing hormone were measured by radioimmunoassay in plasma samples collected daily or on alternate days following insemination in six ‘repeat breeder’ buffaloes. The endocrine profiles in these animals demonstrated that a variety of temporary disturbances in behaviour of these circulating hormones resulted in reproductive failure.
The utilization by calves of formaldehyde-treated maize silages and the response to supplementary protein
Authors: Kaiser A. G. , Osbourn D. F. , England P. , Dhanoa M. S. 
Published: September 2010

ABSTRACTFour silages were prepared from whole crop maize, each receiving additives of 21 1 formic acid per t fresh crop, and 0, 14, 27 or 53 g formaldehyde per kg crude protein in the crop. These silages, together with 19·6 g urea per kg dry matter, were offered ad libitum for 83 days to 60 British Friesian steer calves, initially 99 kg live weight, either alone or with groundnut or fish meal to raise the dietary crude protein content by 27 g/kg dry matter.Formaldehyde treatment restricted silage fermentation, increased silage and dry-matter intake and live-weight gain, but reduced digestibility, so digestible organic matter and digestible energy intakes were unaffected. Much of the increase in live-weight gain appeared to be due to an increase in gut fill, as carcass weight was not significantly affected by formaldehyde treatment. There was no improvement in the utilization of dietary nitrogen, but there was some evidence that formaldehyde treatment may have increased the proportion of muscle in the carcass.Supplementation with protein improved intake, nitrogen retention, feed conversion ratio, live-weight gain and carcass weight. The improvement in intake and food conversion ratio occurred mainly on the control silage, there being little effect on the formaldehyde-treated silages. Fish meal supplementation increased the digestibility of organic matter, cellulose and energy, and was more effective in improving food conversion ratio than groundnut meal. There were no significant differences between diets in the proportion of dietary nitrogen retained.It was concluded that the scope for the use of formaldehyde, when ensiling maize for use in diets for young calves, appears to be limited.
The use of teat-size measurements or calf weaning weight as an aid to selection against teat defects in cattle
Authors: Frisch J. E. 
Published: September 2010

ABSTRACTMeasurements of the median diameter of all teats were recorded within 2 days of calving on 892 cows from eight breeding lines. Teats with a median diameter of ≥35 mm were classed as bottle teats. Their incidence varied from zero in a Hereford line to 0-55 in a Sahiwal crossbred line. In all lines, except the Hereford line, bottle teats were the most important single cause of mortality, up to 2 months of age, of calves that were born alive. However, mortalities became disproportionately high only when all four teats were classed as bottle teats.Of calves that survived to weaning, those born to cows with at least one bottle teat had heavier live weights at weaning than those born to cows without bottle teats. Consequently, more calves were selected for high growth rate as potential sires from cows with bottle teats than from cows without bottle teats. This, combined with the observation that bottle teats occurred only after at least two calvings, is likely to reduce progress towards elimination of the defect through culling. However, indirect culling of the defect through any effect on calf performance is completely ineffective and uneconomic, and it is recommended that cows be culled directly for the defect in the year in which it first appears.
Laboratory evaluation of ensiled poultry litter
Authors: Hadjipanayiotou M. 
Published: September 2010

ABSTRACTPoultry litter collected from a commercial broiler house, bedded with wood shavings, was used. The material was screened and ground before it was ensiled either alone or with other agricultural by-products, namely chopped barley straw, a mixture of weeds and grapefruit peels. The digestible organic matter in the dry matter value in vitro (0·39) for litter was comparable with that for straw and weeds. Of the total nitrogen (36·3 g/kg dry matter), 0·19 was ammonia-nitrogen and 0·77 protein-nitrogen. Digestible energy and crude fibre in the litter were 7·19 MJ and 334 g/kg dry matter, respectively. Addition of poultry litter at ensiling resulted in significant increases in nitrogen and ash content of the original mixtures. Inclusion of sodium hydroxide in fermented and non-fermented mixtures elevated digestible organic matter in the dry matter values in vitro by 0·19 and 0·13, respectively; the crude fibre concentration was lowered. All initial mixtures were free of lactic acid and were positive for the pathogen Proteus when tested. Unlike crude fibre, fatty acid and free ammonia, which were increased after fermentation, digestible organic matter in the dry matter and pH values were decreased. Ensiling killed the pathogen Proteus in the majority of the silages tested. The silages had a pleasant aroma and colour, and were consumed by Chios sheep.
Maternal performance of oxford and suffolk breeds, of sheep, and their crosses
Authors: Fahmy M. H. 
Published: September 2010

ABSTRACTThe proportion of ewes lambing of those exposed to the ram, litter size and weight at lambing, and at weaning, pre-weaning lamb mortality and changes in ewe weight during suckling, were studied in 326 ewes (931 lambings) representing two pure breeds, Oxford and Suffolk, and four crossbreds, Oxford♂ × Suffolk♀, Suffolk♂ × Oxford♀, North Country Cheviot♂ × Oxford♀ and Cheviot♂ × Suffolk♀, mated to purebred and crossbred rams during 9 years. The proportional fertility in the Oxford and Suffolk ewes (0·82 and 0·85 respectively) was lower than that of Suffolk × Oxford (0·93), Oxford × Suffolk (0·94), Cheviot × Oxford (0·88) and Cheviot × Suffolk (0·88) ewes. Litter sizes of Suffolk ewes at birth and at weaning were 1·6 and 1·3 lambs, 0·3 (0·22) and 0·3 (0·27) lambs largeir than those of the Oxford ewes, respectively. The corresponding figures for litter weight were 1·29 kg (0·22) and 11·8 kg (0·36). Oxford ewes lost 0·10 of their weight during nursing compared with 0·14 for the Suffolk and the two reciprocal crosses. The estimates of heterosis in litter size and litter weight at birth were 0·085 and 0·082, and at weaning were 0·13 and 0·18 respectively.The results showed that Oxford crosses were better in performance than the pure Oxford, whereas the Suffolk crosses were similar in performance to the pure Suffolk, except in the proportion of ewes lambing of those exposed and pre-weaning mortality, in which the crosses were 0·07 and 0·20 superior to the pure Suffolk, respectively.Breed of sire had a significant effect on litter weight at birth and at weaning, whereas the interaction breed of sire × breed of dam was a significant source of variation on litter size and litter weight at birth and at weaning. Litter performance at birth was significantly lower in 2-year-old ewes and in ewes sired by 3-year-old or older rams than in other age groups
A note on the effects of the ratio of protein to digestible energy and digestible energy concentration in the diet on performance and nitrogen metabolism of piglets weaned at 21 days of age
Authors: Newport M. J. , Keal H. D. 
Published: September 2010

ABSTRACTPiglets were weaned at 21 days of age, and given diets containing 13·5 or 17·0g crude protein per MJ digestible energy and either 14·7 or 16·8 MJ digestible energy per kg in a 2 × 2 factorial experiment until 56 days of age. There was no effect on performance or food intake when the diets were offered ad libitum, but energy intake was increased with the higher concentration of dietary energy. The higher levels of both protein and energy improved performance in a metabolism experiment with food intake restricted to 0·80 ofad libitumintake, and the higher protein level increased nitrogen retention (g/day per kg live weight) and plasma urea nitrogen. These results suggest that the level of food intake can affect the response to changes in dietary energy and protein concentrations, and indicate that conclusions from metabolism experiments using restricted feeding may be inappropriate under other conditions.
A comparison of boars, gilts and castrates for bacon manufacture 3. Consumer reaction, to bacon from boars and castrates and an economic evaluation of a non-castration policy for bacon manufacture
Authors: Smith W. C. , Ellis M. , Clark J. B. K. , Innes N. 
Published: September 2010

ABSTRACTConsumer reaction to bacon from boars and castrates, whose production and processing characteristics were known, was determined in 122 households consisting of 238 respondents. On a seven-point scale the mean scores for six organoleptic characteristics were similar for each sort of bacon relative to that usually purchased. A proportion of 0·045 of cooks scored boar bacon at the point of strongest rejection (unappetizing aroma) during cooking but less than 001 considered that the flavour was very much stronger than their usual bacon. Few respondents marked boar bacon inferior to their usual bacon for eating characteristics. On a comparative basis the frequency distribution of scores for flavour, juiciness and pleasantness of aroma on the plate was slightly in favour of castrate bacon but was of little importance. Using the production and processing data obtained and accepting no adverse consumer reaction to boar bacon, a financial advantage to the producer of entire male pigs for bacon manufacture over castrates was demonstrated (£2·95). However, if the retailer should not reward the curer for the extra leanness of the boar then the curer might be at a financial disadvantage.
The effects of food intake in gestation on sows lactating for 14 days
Authors: Walker N. 
Published: September 2010

ABSTRACTNinety-two gilts in replicates of four littermates were mated at puberty at a mean live weight and age of 95 kg and 191 days respectively. The littermates were allocated at random to one of four food allowances (kg/day) during four successive gestations: (A) 1·5, (B) 2·0 in parity 1 followed by 1·5 in subsequent parities, (C) 20 and (D) 2·5. A diet calculated to contain 12·7 MJ digestible energy per kg was fed throughout gestation, the 2-week lactation and from weaning to conception.The numbers of sows which conceived at parity 5 when the experiment terminated were 10, 12, 13 and 16 for treatments A to D respectively. Sow live weight at conception differed significantly (P< 0·01) from parity 2 onwards: the maximum live weights of sows on treatments A and B did not exceed 130 to 135 kg, but the live weights of sows on treatment D continued to increase to reach 195 kg at the end of the experiment. The in vivo skin plus subcutaneous fat thickness at the P2 location differed significantly (P< 0·001) between treatments from parity 2 onwards, decreasing by 3 mm in treatment A and increasing by 6 mm in treatment D from the start of the experiment to conception at parity 4. The interval from weaning to conception was significantly (P< 0·05) lower in treatment B in parity 2. This was the only significant effect and was contrary to the tendency for the interval to increase as the food allowance in gestation was decreased. The numbers of pigs born alive, stillborn or weaned (including fostered pigs) were not significantly affected by treatment. Birth weight and post-natal growth rates were significantly (P< 0·05) increased after parity 1 as gestation food allowance increased, with the exception of the post-natal growth rate in parity 3. Overall birth weight was increased by 018 kg per pig and weaning weight by 0·93 kg per pig on treatment D compared with treatment A.
Factors affecting patterns of development and their assessment
Authors: Seebeck R. M. 
Published: September 2010

ABSTRACTThe effect of rate of growth on the development of animals is examined in terms of it being related to variation from a pattern of development described by the allometric hypothesis. For this purpose, aliometry is expressed in terms of an extension to the shape/size concept originally proposed by Mosimann.It is shown that such an effect of rate of growth would bias estimates of the development pattern, depending on the experimental design. However, within the framework of the method, a procedure for both removing the bias and actually estimating the effect of rate of growth on development is available.A previously described test for one type of deviation from aliometry is shown to be incorrect by simulation.An alternative test for the adequacy of the allometry hypothesis is developed, based on factor analysis of residual matrices from multivariate analysis of variance (the latter being used so that effects of treatment and concomitant variables can be taken into account).