bluuebunny/crossref_metadata_2025 huggingface dataset:
On-farm performance of Bunaji (White Fulani) cattle 1. Herd structures and cattle disposal
Authors: Rege J. E. O. , von Kaufmann R. R. , Mani R. I.
Published: September 2010

A study urns conducted to examine herd structures and cattle disposal patterns of Bunaji herds kept under traditional management at four locations in the subhumid zone of Nigeria. Sale for meat was the single most important disposal reason, accounting for proportionately 0·55 of all disposals. Mean age of cattle sold for meat was 8 years but the age range was wide: animals as old as 17·4 years were involved in such sales. Male animals were sold at a younger age (6·2 years) than females (9·3 years). Sale of calves was an important exit avenue for rural herds with less access to milk market. Calves were sold at a mean age of 1·1 years and male calves accounted for a larger proportion (0·62) of such sales. Animal sales were highest in the early dry season and lowest in the early wet season. The predominantly arable farming location, Ganawuri, had the highest frequency of animal sales and lowest frequency of exits for ‘social functions’ (exchanges, transfers and gifts). Animal transfers, gifts and exchanges were important disposal routes in the traditionally pastoral communities, especially in locations with good grazing (e.g. Abet). Exits involving exchanges, transfers and gifts were more frequent during the dry season and least frequent in the wet season. An average herd had 77 head of cattle composed proportionately of 0·54 adult females (>3 years), 0·13 adult males (>3 years), 0·08 young bulls (1 to 3 years), 0·13 heifers (1 to 3 years) and 0·11 calves (0 to 1 year). There was a tendency toward smaller herds in later years (97 in 1980 to 51 in 1989) and a decrease in the ratio of adult females to males (from 6:1 in 1980 to 3:1 in 1989). Substantial between-location differences existed in herd size ami herd structure, ranging from the ‘beef orientation’ of the arable Ganawuri with a high proportion of immatures and calves, to the pastoral situation in Abet and Kurmin Biri with high proportion of adult animals. The proportions of adults were lowest in the early dry season, reflecting seasonal pattern in disposal and calving. The pattern in disposal reasons over time indicated a decrease in the proportion of animals exiting herds through exchanges, transfers and gifts and signified a possible shift from tradition, probably a response to population pressures and emergence of cash economies.
On-farm performance of Bunaji (White Fulani) cattle 2. Growth, reproductive performance, milk offtake and mortality
Authors: Rege J. E. O. , von Kaufmann R. R. , Mwenya W. N. M. , Otchere E. O. , Mani R. I.
Published: September 2010

An on-farm study was conducted over a 12-year period (1979 through 1990) at four locations in the subhumid zone of Nigeria to estimate levels of performance of Bunaji cattle and to examine factors affecting productivity in these production systems. Average weight at birth, at 9 months and at 12 months were 19·6 kg, 76·2 kg and 93·1 kg, respectively. Average daily gain between birth and 9 months was 211 g/day. The corresponding figure between 9 months and 12 months was 176 g/day. Cumulative calf mortality at 9 months and at 12 months were proportionately 0·14 and 0·15, respectively. Mean age at first calving was 62·5 months while interval between consecutive calvings averaged 22·5 months. Mean daily milk offtake was 510 ml. Mean length of offtake period varied substantially between locations ranging from 339 days in Kurmin Biri to 425 days in Madauchi. Lactation milk offtake was estimated at between 200 and 260 I. Peri-urban Madauchi had the highest daily milk offtake, the longest milk extraction period but the poorest calf growth and survival rates. Locations with low milk offtake had superior calf performance both in terms of growth and survival. Calves born in late wet and early dry seasons had superior growth and survival rates. Most calvings occurred in the dry season mainly because of the effect of season on conception rates. There was a tendency towards improved productivity on a per-animal basis over the years. This ivas so for age at first calving, calving interval, calf survival and milk offtake. Improved reproductive performance provided opportunity for higher offtakes. However, growth between 9 months and 12 months and weight at 12 months declined during the study period.
Effects of rapeseed-meal and fish-meal supplementation of maize silage-based diets upon voluntary intake, live-weight gain and wool growth of store lambs
Authors: Kossaibati M. A. , Bryant M. J.
Published: September 2010

Thirty-six individually penned lambs (mean live weight 32·4 (s.d. 2·27) kg) were offered maize silagead libitumand one of three concentrate mixes, two of which contained extracted rapeseed meal (control and HR) and the other fish meal (FM). The concentrates were given according to live weight and in sufficient quantities to provide proportionately about 0·4 of the dry matter (DM) intake of the lambs. The dietary concentrations of nitrogen (N) g/kg DM were 22·4, 27·4 and 27·5 and of rumen undegradable N 6·6, 7·3 and 11·6 for the control, HR and FM diets respectively.

Both the HR and FM diets depressed maize silage intakes compared with the control during the first 21 days (P < 0·05) and lambs given the FM diet continued to have lower intakes than control lambs (P < 0·05) throughout the experiment. The live-weight gain of HR lambs was considerably depressed in comparison with the control and FM lambs during the first 21 days of the experiment (P < 0·05). Overall HR lambs gained weight more slowly than control and FM lambs up to 45 kg live weight but the difference was not statistically significant. Food conversion ratio was better for FM than HR (P < 0·01). There were no treatment differences in wool growth.

The results obtained provide little evidence that fish meal had any beneficial effects upon lamb growth compared with the control diet except a possible increase in the efficiency of metabolizable energy utilization.
Fish-meal supplement for severely undernourished ewes: effects on apparent digestibility and utilization of the diet
Authors: Kabré P. , Petit M.
Published: September 2010

Eight non-pregnant, non-lactating adult ewes weighing 56 kg were fed for 26 days on a meadow hay (organic matter 937 g, crude protein 107 g, metabolizable energy (ME) 8·3 MJ per kg dry matter) to satisfy half of their daily energy and protein maintenance requirements i.e. 200 kj ME and 1·3 g truly digestible protein per kg M0·75. They were then allotted to two groups of four each. Control ewes continued to receive the initial diet for another 74 days while the others were supplemented with 60 g/day fish meal to receive 200 kj ME and 2·7 g truly digestible protein per kg initial M0·75 per day.

In spite of its high nitrogen content, the digestibility of the hay was increased by the protein supplementation, e.g. from 0·56 to 0·60 for neutral-detergent fibre and from 0·54 to 0·59 for energy.

The supplemented ewes lost significantly less body weight than the controls (96 v. 134 g/day) essentially because of their higher ME intake (272 v. 252 kj/kg average M0·75 during the experimental period). The measurements of blood metabolites suggest that the daily amounts of mobilized body protein increased with duration of underfeeding. The additional amino acids provided by fish meal were principally used as a source of energy and for wool growth.
Cashmere production from feral and imported cashmere goat kids
Authors: Bishop S. C. , Russel A. J. F.
Published: September 2010

Cashmere production was evaluated on Scottish feral (F) goats, on goats imported from Iceland (I), Tasmania (T), New Zealand (N) and Siberia (S), and on two- and three-way crosses between feral and imported lines. Evaluations were based on the weight of cashmere in 10 cm2 mid-side patch samples taken at 5 months of age, with annual cashmere production being predicted from sample cashmere and body weights. Data were collected on 121 purebred and 706 crossbred kids of both sexes. Mean fibre diameter for the F, I, T, N and S lines was 13-75 (s.e. = 0.82), 14·04 (s.e. 0·41), 16·13 (s.e. 0·35), 16·63 (s.e. 0·49) and 17·97 (s.e. 0·50) μm, mean estimated annual cashmere production was 37·3 (s.e. 71·3), 914 (s.e. 31·7), 227·1 (s.e. 28·1), 275·1 (s.e. 42·5) and 579·8 (s.e. 44·7) g, and mean live weight was 15·71 (s.e. 2·16), 17·65 (s.e. 0·93), 16·39 (s.e. 0·83), 16·53 (s.e. 1·28) and 21·9 (s.e. 1·28) kg, respectively. Significant positive heterosis existed between some lines for body weight and cashmere production, with the I line goats consistently showing the largest effects. Combining fibre diameter and cashmere production by their relative economic importance into an index designed to indicate the total value of the fibre produced by each genotype, the cashmere production index, reduced the large production differences between the lines, although the S line was still superior to all other lines. When the cashmere production index was adjusted to account for the economic importance of fibre colour, however, the T and N lines, the only lines which produced white fibre, were comparable to the S line. The cashmere production index for the S line was very sensitive to changes in the relative economic weight for fibre diameter, and if the price differential for high quality (i.e. fine) fibre was increased by a factor of 1·36, or greater, then the T and N lines were superior to the S line. Three-way cross means were estimated from line means and heterosis effects. No cross was consistently superior to all other genotypes, but several of the crosses showed the advantages of potentially producing white fibre as well as having high cashmere production indexes, with their indexes being insensitive to changes in the relative economic weights. Future selection for cashmere production in this population should concentrate on individuals of outstanding genetic merit, regardless of their line or cross.
Effect of naturally occurring and synthetic androgens on growth, body composition and muscle glucocorticoid receptors in wether lambs
Authors: Gallbraith H. , Berry A. D.
Published: September 2010

Twenty-five Border Leicester ♂ × Blackface ♀ wether lambs aged about 4 months and weighing on average 28·5 kg were allocated to be treated with the naturally occurring steroid testosterone or trenbolone acetate or nandrolone phenylpropionate which are steroids synthetically produced. Treatment groups were as follows: untreated controls (C); 50 mg testosterone (T); 50 mg trenbolone acetate (TA); 50 mg testosterone + 50 mg trenbolone acetate (TTA) or 50 mg nandrolone phenylpropionate (N). Implants were given at 100 and again at 63 days before slaughter. The lambs were offered to appetite a good quality diet containing, per kg dry matter, an estimated 11·0 MJ metabolizable energy and 185 g crude protein. Comparisons were made for the main effects of T and TA and also interactions between T and TA. Effects due to N were assessed statistically against untreated controls. Treatment with T, on average, increased live-weight gain (LWG), empty body weight (EBW) and reduced backfat thickness and the weight (g/kg EBW) of perirenal and retroperitoneal fat. Main effects due to TA were increases in killing-out ratio and depth of the gigot joint and reductions in backfat thickness. Treatment with N increased the empty body weight and (g/kg) carcass ash. Non-significant (P > 0·05) trends were suggested for increases in carcass crude protein due to T and TA treatments. T and TA but not N treatments exhibited marked androgenic activity in increasing the weight (mg/kg EBW) of the accessary vesicular gland. TA and N, but not T, reduced the weight (g/kg EBW) of the thymus gland.

The maximum binding capacity of post-morte m skeletal muscle (m. gluteus) for (3H)-dexamethasone was reduced by TA but increased by T and N. These results suggest differences in the binding capacity of corticosteroid receptors which may be related to differences in the effects of T and TA on protein metabolism in skeletal muscle.
A note on the effect of number and genotype of kids on milk yield and composition of indigenous Greek goats (Capra prisca)
Authors: Zygoyiannis D.
Published: September 2010

Four groups of 10 indigenous goats, suckling indigenous or crossbred, single or twin kids, were used to study the effect of sucking stimulus on milk yield and composition during a 12-week suckling period and over the first 20 weeks of the subsequent milking period. During the suckling period, goats with twins produced more milk (F < 0·001) than those with singles. There was no effect of kid genotype in goats rearing twins but single crossbreds took 1·11 times more milk than indigenous. Goats with single kids had higher concentrations of fat (F < 0·001), protein (F < 0·05) and lactose (F < 0·05) in milk than did those with twins. Growth rate of kids was related to differences in milk intake, with singles higher than twins (F < 0·001) and crossbred singles higher than indigenous singles (F < 0·05). It is concluded that the indigenous breed can respond to the increased sucking demand of twins but not sufficiently to meet their needs. During the milking period the mean yield was reduced to about one-third and was not dependent on the corresponding yield in the suckling period. There were minor differences of milk composition associated with number or genotype of kids suckled.
MOET breeding schemes for wool sheep 1. Design alternatives
Authors: Wray N. R. , Goddard M. E.
Published: September 2010

Breeding schemes for ivool sheep based on natural service (N), MOET (multiple ovulation and embryo transfer) in adults (A) and MOET in juveniles (J) are compared using Monte Carlo simulation allowing overlapping generations and selection across age groups. In all schemes parents can be a maximum of 6 years old when their offspring are born, and can be a minimum of 2 years in N or A schemes or 1 year in f schemes. Embryo transfer success rates follow realistic distributions (only 70% of flushes resulting in live lambs) with a mean of 2·13 or 345 6-month-old lambs per donor per flush for current or ‘future’ situations. Under natural mating an average of 1·09 6-month-old lambs per ewe mated is assumed. The trait under selection has a heritability of 0·4 and is measurable on both sexes by 18 months of age, which is before selection in N and A schemes but after the initial opportunity for selection in f schemes where selection is based on a pedigree index. Two culling policies for males are considered in J schemes: all sires culled if not selected (J), or all sires available for selection after their record is collected even if they were not selected on their pedigree index in the previous year (f o ). Comparison of schemes is made on the basis of response depressed by the effect of inbreeding and cumulated and discounted over a medium time horizon. For a given population size (constant expected number of lambs per year and therefore numbers of dams dependent on fertility rates) different numbers of sires were utilized. The optimum number of sires was determined as the number which maximized the response criterion. N, A, J and J° schemes have different optimum numbers of sires (5, 8,30 and 20 respectively) which occur at different rates of inbreeding and which are approximately independent of population size. Advantages in the response criterion of A, J and J° over N schemes are 23%, 33% and 47% respectively for ‘future’ embryo transfer success rates and mass selection. Increasing the number of lambs born per donor ewe from 2·13 to 13·8 (by increasing embryos per flush and number of flushes) increases the response criterion by up to 25% in A and up to 11% in J schemes (assuming donor ewes are mated to a different sire for each flush) with 345 lambs born per year. Use of best linear unbiased prediction (BLUP) estimated breeding values increases response by 8%, 3% and 3% in N, A and J schemes respectively. The advantages off over A and N schemes, of increased lambs per donor and of BLUP over mass selection all increase as population size increases. Insemination of the poorer ewes with semen which gave only female offspring gave 5% increase in the N scheme and no benefit in A or f schemes.
MOET breeding schemes for wool sheep 2. Selection for adult fleece traits
Authors: Wray N. R. , Goddard M. E.
Published: September 2010

Benefits of collection of annual versus a single fleece record are investigated for breeding programmes of Australian Merino sheep. Breeding scheme alternatives are based on natural mating (N) or multiple ovulation and embryo transfer (MOET). The breeding objective is assumed to be an adult fleece trait which is expressed annually from a minimum of age 2 years, with a unity genetic correlation between annual records. Initial selection of parents can occur prior to the availability of their adult records, based on records collected at 6,12 or 18 months which have a maximum genetic correlation of 0·8 with the adult trait. Monte Carlo simulation is used to compare breeding programme alternatives, which allows overlapping generations and selection across age groups. MOET schemes select parents of minimum age 19 months in adult (A) schemes, 7 months in juvenile (J) schemes or 13 months when there are two breeding seasons per year. Natural mating results in an average of 1·09 lambs per ewe mated, whilst embryo transfer success rates follow realistic distributions (only 70% of donors giving live lambs) with an average of 3·45 lambs per donor flushed. Estimated breeding values, on which selection is based, are calculated by multiple trait selection index of an individual's own records or by multivariate best linear unbiased prediction (BLUP). In J schemes 7-month-old lambs may be selected on the basis of a pedigree index if no individual record has been collected at 6 months of age. Breeding scheme alternatives are compared on the basis of genetic response, rate of inbreeding and economic ‘income’ which is calculated as genetic response reduced for inbreeding depression, cumulated and discounted over a medium time horizon (14 years). The quantitative benefits of the collection of annual records are dependent on the choice of genetic and phenotypic parameters between traits, but these were chosen from the literature to be representative of annual fleece weight records in Merino sheep. Genetic response to selection and ‘income’ associated with the adult trait is increased by at least 15% in N, A and J schemes compared with when only a single record is collected at 18 months. The advantage of MOET over N schemes and the optimum number of sires to use is unchanged, but the average age of sires is increased. Both annual rate of inbreeding and average age of dams are unchanged. In N schemes, 80% of the benefits of collecting annual records on both sexes can be achieved by collecting records on males alone, whilst in MOET schemes measurement of dams contributes up to 50% of the benefit of the measurement of both sexes. Since MOET schemes have fewer dams to be recorded, the cost-effectiveness of collecting records on females is much higher than in natural mating schemes. Breeding programmes operating two mating seasons each year are found to be a viable alternative to J schemes: although genetic response is less, rate of inbreeding is also less, so that ‘income’ response is approximately equal.
The effect of climatic environment and relocating and mixing on health status and productivity of pigs
Authors: Hessing M. J. C. , Tielen M. J. M.
Published: September 2010

Two similar style experiments were carried out in a climate-controlled pig house to determine the effects of adverse climatic conditions and relocating and mixing on the health status and productivity of pigs. In both experiments, 120 pigs were used. The climate-controlled pig house consisted of two fully separated but identical rooms (experimental and control) with five pens each (12 pigs per pen). Pigs exposed to draught and low environmental temperature had lower daily gain (experiment 1: 45 g/day; experiment 2: 25 g/day) and higher food conversion (food: gain ratio) than pigs housed under optimal climatic conditions (control). Moreover, clinical disease signs (i.e. diarrhoea, coughing, sneezing and haemorrhagic ear lesions) were more pronounced in the experimental than in the control group. In experiment 1, pigs were relocated and mixed at 10 weeks of age either within or between the experimental and control room. Data showed clear negative effects on daily gain and clinical disease signs especially among pigs that were relocated to suboptimal climatic conditions. In experiment 2, pigs were either relocated and mixed between both rooms or they remained in their own pens. Data on daily gain and clinical disease signs revealed that the health of the pigs was strongly affected by mixing. Therefore, the present work emphasizes the importance of climatic environment and social factors in intensive pig production.
A note on changes to feeding behaviour of growing pigs by fitting stalls to single-space feeders
Authors: Morrow A. T. S. , Walker N.
Published: September 2010

A two-treatment experiment was made involving 340 crossbred pigs penned in groups of 20 and offered a cereal-based, non-pelleted diet ad libitum from one single-space hopper per pen supplying both food and water. Half the feeders were fitted with stalls which protected the feeding pig from its pen mates. The average number of visits per day to the feeder was reduced from 20·1 to 11·9 (s.e. 1·58, P<0·01) by fitting the stall and the average duration of each visit was increased from 2·06 min to 4·18 min (s.e. 0·298, P < 0·02). The total time of occupation and its circadian pattern were similar for both treatments There were reductions in the incidence of enforced withdrawals (12·7 v. 3·4 (s.e. 0·75), P < 0·001) and of pigs queuing (28·6 v. 84 (s.e. 2·35), P < 0·001) with the addition of a stall which also reduced the occurrence of tail biting. Although the stall improved pig welfare the anticipated reduction in food spillage was not evident.
Effect of time of supplementary feeding on intake, apparent digestibility and rumen fermentation of grass hay by sheep
Authors: Carro M. D. , Mantecón A. R. , Wright I. A. , Gordon I. J.
Published: September 2010

Effects of time of supplementation on forage intake, nutrient apparent digestibility and rumen fermentation were studied with 12 mature castrated male sheep (wethers) offered grass hay from 16.30 h to 09.30 h and supplemented with a cereal-based concentrate given at either 09.30 or 16.00 h. Voluntary intake of hay organic matter (OM) was decreased by feeding the concentrate (P< 0·01). Offering concentrate at 09.30 h after hay was available, increased intake of hay and total OM compared with offering it at 16.00 h before hay was available (P< 0·05). Daily pattern of hay intake was not changed when concentrate was offered at 09.30 h compared with feeding hay alone, but concentrate given at 16.00 h resulted in a lower hay intake between 16.30 and 18.00 h. Sheep offered concentrate at 09.30 h had higher rumen ammonia levels than those offered concentrate at 16.00 h, but there were no differences in the apparent digestibility of the nutrients, rumen pH and molar proportions of the main volatile fatty acids. There were also no differences between groups in the blood plasma concentrations of 3-hydroxybutyrate (30HB), nonesterified fatty acids (NEFA) and glucose. It is concluded that feeding supplement after rather than before a period of intake of forage or a bout of grazing may offer a means of minimizing reduction of forage intake as a consequence of feeding concentrate.
Genetically size-scaled growth and composition of Dorset and Suffolk rams
Authors: Oberbauer A. M. , Arnold A. M. , Thonney M. L.
Published: September 2010

Thirty-four Dorset and 34 Suffolk rams were slaughtered in pairs within breed at birth, weaning, at monthly intervals to 420 days and then at bimonthly intervals until 600 days to compare factors used to estimate mature size and to determine how genetic size-scaling affects the comparison of body composition between breeds. At equal empty body weights there were no detectable differences between the breeds in amounts of water, protein or ash but Dorsets contained more lipid. Dorset and Suffolk asymptotic values of water (40 and 61 kg), water-plus-protein-plus-ash (51 and 77 kg), metacarpal bone length (127 and 147 mm) and metacarpal bone weight (59 and 101 g) were used to estimate mature size. Regardless of the estimator of mature size, there were no significant differences between breeds in degree of maturity at a given metabolic age. At the same degree of maturity within the estimators of mature size, there were no differences between breeds in the degree of maturity of water, protein or ash, with the exception of small differences in protein for two of the mature size indicators. Because lipid appeared to accumulate without limit in these sheep, the mature body was assumed to contain 300 g lipid per kg. Using this proportion to estimate amount of mature lipid, there was a higher degree of maturity of lipid for Suffolk than for Dorset rams at equal degrees of maturity of water, water-plus-protein-plus-ash or metacarpal bone weight. Thus, Dorsets with greater lipid content at equivalent empty body weights were leaner than Suffolks when adjusted for mature size.
Milk production from grass silage diets: the relative importance of the amounts of energy and crude protein in the concentrates
Authors: Sutton J. D. , Aston K. , Beever D. E. , Fisher W. J.
Published: September 2010

To identify the separate and combined effects of energy and crude protein (CP) from concentrates on responses to concentrate feeding, 42 multiparous Friesian cows were given fixed amounts of concentrates with primary growth grass silage (194 g CP per kg dry matter (DM)) ad libitum for weeks 4 to 22 of lactation. A basal treatment of 3 kg DM per day of a standard concentrate (197 g CP per kg DM) was compared with 6 kg DM per day of the same concentrate (doubling energy and CP intake), 6 kg DM per day of a low-protein concentrate (106 g CP per kg DM) (doubling energy intake alone), or 3 kg/day of a high-protein concentrate (383 g CP per kg DM) (doubling CP intake alone). Results are presented in terms of main effects as interactions were not significant except for energy apparent digestibility. Silage intake was reduced by energy but increased by CP; in consequence extra energy from concentrates increased digestible energy (DE) intake but reduced CP intake and concentration whereas extra CP from concentrates increased not only DE intake but also CP intake and concentration. The ratio of the responses to CP compared with the responses to energy were 1·7 for milk yield, 0·9 for fat yield, 3·2 for protein yield and 1·4 for lactose yield. Energy reduced milk protein concentration and tended to increase milk fat concentration whereas CP had the opposite effect. The efficiency of converting food nitrogen to milk nitrogen was unaffected by extra CP but was increased, from 0·195 to 0·229, by extra energy. The poor response in milk protein yield and the reduction in its concentration with extra energy reflected the lower CP intake due to the reduced silage consumption. The experiment emphasizes the importance of concentrate CP supply in stimulating silage intake and yields of all milk constituents for diets containing fairly small amounts of concentrates.
A note on relationship of plasma thyroxine and triiodothyronine rate to body weight in growing male camels
Authors: Alfuraiji M. M. , Basmaeil S. M. , Gamil M. H.
Published: September 2010

This study was conducted to determine the relationship between plasma concentrations of thyroxine (T4), triiodothyronine (T3) and body weight in young Majaheem male camels. Eighteen camels aged 6 to 7 months were divided equally into three groups (Gl, G2 and G3). All groups were given concentrate pellets (187 g crude protein per kg) at the rate of 15 g/kg body weight daily. In addition, each group was given one of the following roughages: lucerne hay to Gl, rhodes grass hay to G2 and ammonia-treated wheat straw to G3. Roughages, salt and water were measured and given ad libitum. Every 2 weeks all camels were weighed and blood samples were collected. Data were statistically analysed using a general linear model procedure. There was a positive correlation between T4 concentration and body weight. T4 was higher in camels given either hay or straw compared with those given rhodes grass hay, while there were no differences among the three groups in T3 and in body weight.
A partial adjustment model to describe the lactation curve of a dairy cow
Authors: Dhanoa M. S. , Du Y. L. P. Le
Published: September 2010

A new model is proposed to describe the lactation curve of a dairy cow. It uses the fact that milk yield at a given stage of lactation is largely determined by the yield in the preceding stage. The model is written as: yt = λ(m0 – m1t) + (1 – λ)yt–1. t ≥ 1, 0 ≤ λ ≤ 1, where y1, and yt–1 are the current and preceding milk yields in kg/week, and the constant × estimates the fraction (1–λ) by which milk yield adjusts to the level at the next stage. The fraction (1–λ) by which the milk yield persists at the preceding level is used to define a measure of persistency, P = (1–λ)m0/m1 weeks, where m1 is the rate of decline in kg/week and m0 is a constant.
An economic assessment of pale, soft exudative musculature in the fresh and cured pig carcass
Authors: Smith W. C. , Lesser D.
Published: September 2010

A study was undertaken to determine the magnitude of any financial loss incurred in the utilization of pale, soft exudative (PSE) pigmeat. Twenty pairs of first-grade bacon-weight carcasses were selected on the slaughter line. Members of each pair were of the same sex and weight but one had an m. longissimus dorsi pH at 45 min post mortem (pH1) of 5·4 to 5·8 (PSE) and the other a pH, of 6·2 to 6·5 (normal). One side of each carcass was processed for Wiltshire bacon and the other was cut into retail joints, which were packaged, placed in a refrigerated cabinet and measured for drip loss 72 h later. PSE, compared with normal carcasses, had a lower bacon yield (16g/kg) and drip loss from fresh PSE meat was more than double (17·0 v. 7·0g/kg trimmed carcass weight). In shop testing, the sales of bacon from the two types of carcass were similar; with the fresh meat fewer PSE cuts were sold (0·23) but mainly during the final test day. It would appear that an economic assessment of PSE meat in Wiltshire curing need consider a reduced bacon yield only (= £1·13 per carcass at the present difference of 0·8 kg). The reduced financial return on a PSE carcass of similar weight for fresh meat was calculated to be zero to £8·74, depending upon the type of retailing operation and effort devoted to ensuring an early sale of PSE cuts.
Effect of pregnancy and lactation on growth of linear measurements in Ayrshire cattle
Authors: Russell W. S.
Published: September 2010

The effects of pregnancy and lactation on growth were investigated in Ayrshire cattle, from data on 12 linear body measurements at 3-monthly intervals up to 4 years of age. In all, 9 888 sets of 12 measurements were obtained. There were 675 first and 518 second calvings.

When expressed as a percentage of the size of animals of the same age but in a non-pregnant, non-lactating state, the total set-back to normal growth due to pregancy and lactation ranged from 2% in withers height to 18% in forerib width in heifers, and from 1% to 3% for the same characters in cows.

All 12 measurements were affected significantly by first pregnancy (including parturition), the average retardation being 3%. For several measurements, a check to growth during pregnancy was largely obscured by progressive distention of the body, especially in measurements of width, until parturition had occurred. Thus a retardation of 9% in forerib width became apparent only after calving.

First lactation affected significantly most measurements, especially the later-maturing six, which were set-back in their normal growth over the lactation period by 3% to 9%. Thus, there was effectively zero- growth in width at forerib and only one-sixth of normal growth in foregirth, whilst growth rate in width at pins and hooks was approximately halved by lactation.

Calving at an earlier than average age affected growth adversely and thereby involved some increased risk of calving difficulties.
Production characteristics of high-yielding dairy cows
Authors: Neilson D. R. , Whittemore C. T. , Lewis M. , Alliston J. C. , Roberts D. J. , Hodgson-Jones L. S. , Mills J. , Parkinson H. , Prescott J. H. D.
Published: September 2010

Understanding the relationships between food intake, milk output and body condition in high-yielding dairy cows is crucial in determining suitable management strategies. During two winter feeding periods 38 and 37 cows were individually fed, to appetite, complete diets which on average contained 11·7 MJ metabolizable energy per kg dry matter and comprised grass silage, concentrate meal and brewers' grains (draff). The groups' mean 305-day yield was 7 240 kg (s.d. 1 281) with 42 g (s.d. 4·3) fat per kg. Regression analysis was carried out to describe dry-matter intake both for 26 weeks post calving and for four successive 6-week periods from calving. The final equations, which had a residual s.d. of 0·07 to 0·10 of the observed intake, included milk yield, cow size and a measure of body-condition change. The cows were divided into three groups (high, medium and low) on two criteria: (1) mean milk yield (MJ/day) during the first 26 weeks of lactation and (2) post-calving backfat index determined ultrasonically. Differences were found between milk-yield groups from gross efficiency (milk yield (MJ)/energy intake (MJ metabolizable energy)) (P < 0·001), mean metabolizable energy intake (MJ/day) (P < 0·01), dry-matter intake as a proportion of live weight (P < 0·05), and post calving live weight (kg) (P < 0·05). Differences were found between backfat-index groups for maximum backfat loss and loss to day 42 (P < 0·001); also for mean live weight during the 26 weeks and post calving live weight (P < 0·001), dry-matter intake as a proportion of live weight (P < 0·05) and lactation number (P < 0·05). Interactions were found between the milk yield groups and backfat groups for milk yield (P < 0·01) and gross efficiency (P < 0·05) with the fattest group containing the highest and lowest yields and efficiencies.
Variation in milk cell counts during lactation of British Friesian cattle
Authors: Wood P. D. P. , Booth J. M.
Published: September 2010

A survey was carried out of 1 640 British Friesian heifers calving predominantly in the autumn of 1979. The monthly samples of 1 055 animals showing no reported evidence of udder infection were used to evaluate the parameters of a lactation curve in milk cell count. The model was

C = 190 n−0.4880exp(0·178n)

where C is the monthly cell count in millions per 1 during the nth month of lactation. The cell count varied from 230 × 106 in week 1 and 190 × 106 in week 11 to 400 × 106 in week 44 of lactation.

On applying the model to the whole sample, milk sampled within a month before or after antibiotic treatment for clinical mastitis contained more than 200 × 106 cells per 1 above the level suggested by the lactation curve. Lactation mean cell counts of treated cows were 400 × 106 cells per 1 higher than those of untreated cows. It was not possible to identify periods in which cows required treatment, or those with high cell counts, by reference to the lactose concentration in the milk samples. Among the untreated cows, the cell count at the third monthly test-day was lower than at any other time, and was more highly correlated with the lactation mean cell count.
Increased rates of genetic change in dairy cattle by embryo transfer and splitting
Authors: Nicholas F. W. , Smith C.
Published: September 2010

Possibilities for increased rates of genetic change in dairy cattle through embryo transfer and embryo splitting are examined, using the multiple ovulation and embryo transfer systems previously proposed. These involve embryo transfer from 1-year-old females (juvenile scheme, generation interval 1·8 years) and from females after 1 lactation (adult scheme, generation interval 3·7 years), with use of males at similar ages. Though selection is less accurate than in conventional progeny testing, the annual rate of genetic improvement can be increased, and even doubled. If the number of transfers is restricted andm the inbreeding rate is limiting, the adult scheme for both sexes is preferred. A scheme with 1 024 transfers per year and 512 females milk-recorded per year will sustain a rate of genetic improvement some 30% above that possible by a conventional national progeny-testing programme. Because of the relatively small number of animals involved, it is argued that greater control over recording, breeding and selection should be possible, leading to a larger proportion of the possible genetic gains being realized in practice. Other advantages, and disadvantages of these systems, and their integration in dairy cattle improvement are discussed.
Comparative performance and body composition of control and selection line large white pigs 1. On a generous fixed feeding scale for a fixed time
Authors: Henderson Ruth , Whittemore C. T. , Ellis M. , Smith W. C. , Laird R. , Phillips P.
Published: September 2010

Growth performance and body composition differences between Large White control (C) and 10th generation index-selected (S) pigs were evaluated on a fixed food, fixed time trial. This avoided the complicated interpretation associated with interacting variations in food intake, days on test and body composition. Thirty-nine C and 40 S boars were slaughtered, their carcasses dissected and whole empty bodies minced and chemically analysed after an 84-day trial starting at 26·6 ± 0·27 kg live weight. S boars were older at the start of test (95·2 v. 89·0 days, P < 0·001), were heavier at the end of test (96·2 v. 93·8 kg, P < 001) and converted food more efficiently (0·392 v. 0·378 kg gain per kg food, P < 0·01) than C boars. Bodies of S boars contained more water (48·3 v. 45·9 kg, P < 0·001), less lipid (17·4 v. 18·8 kg, P < 0·001) less gross energy (1 004 v. 1 045 MJ, P < 0·05), but similar amounts of protein (13·8 v. 13·4 kg, NS) compared with C boars. S carcasses contained more lean (34·1 v. 31·8 kg, P < 0·001), less subcutaneous fat (12·5 v. 13·7 kg, P < 0·001), and had lower P2 backfat depths (15·8 v. 18·3 mm, P < 0·001) than C carcasses. Although carcass leanness had been increased, 10 generations of index selection had also reduced the overall energetic efficiency of the selection line, apparently by increasing non-productive heat loss.
A comparison of the nursing and suckling behaviour of group- and individually-housed sows and their litters
Authors: Bryant M. J. , Rowlinson P. , Van der Steen H. A. M.
Published: September 2010

Nursing frequency, suckling duration and teat order were recorded in 12 ‘hybrid’ sows and their litters from parturition to weaning at day 42 post partum. Sows and their litters were moved from the farrowing quarters at day 20; half were housed as a group (G) and fed ad libitum with a boar present and the other half were housed individually (S) with no boar present and ration-fed to scale.

Some differences occurred in behaviour from day 20. A significantly greater number of false nursing periods, significant synchronization of nursing periods, and a tendency for more long and short nursing intervals occurred in G than S sows and litters. The duration of the preliminary nosing phase and the total nursing period were significantly longer in S than G litters. Teat order scores, indicating consistency of piglet suckling position on the sow, tended to be greater in S than G litters, and there was a fall in the score for G litters in the weeks following grouping. This was associated with a check in live-weight gain.

All G sows showed oestrus during lactation, on average 15 days after grouping. There was no incidence of lactational oestrus in the S sows which showed oestrus 5 days after weaning.
Effects of diets consisting of maize and milk on growth and carcass characteristics of mice
Authors: Bateman Nigel
Published: September 2010

Diets of cooked maize meal and dried skim milk were fed to newly weaned mice for 2 weeks, and to lactating females for 3 weeks. The diets ranged from 16% to 100% maize, with complementary amounts of from 84% to 0% milk and a 5% supplement of yeast.

Live-weight gains from 3 to 5 weeks of age were greatest when an intermediate diet containing 76% maize was fed. Average gains on 16%, 76% and 100% maize were 8·0 g, 17·7 g and 5·5 g respectively. The full sib phenotypic correlation was 0·45 but gains were independent of weaning weight. No carry-over effect was detected from maize-milk diets that had been fed to the dams; the dams' own gains at the same age had little influence on their offspring.

Weight of food consumed per mouse varied little between diets despite marked differences in gain. Food and energy intakes relative to gain showed no trend between 16% and 88% maize but doubled between 88% and 100% maize. Protein was used most economically for gains on 88% maize.

There were health problems. When high milk diets were first used many mice suffered from diarrhoea. A few mice on 95% maize, whose dams had been given the same diet during lactation, died without prior symptoms. Mice on 100% maize were thirsty, but not glycosuric.

Females nursing litters on high milk or high maize diets drew on reserves in the carcass, liver, pancreas, spleen and fat. In addition, high milk diets caused hypertrophy of kidneys and caecum, and diarrhoea.
Moist barley for growing pigs: some effects of storage method and processing
Authors: Livingstone R. M. , Denerley H. , Stewart C. S. , Elsley F. W. H.
Published: September 2010

Forty-eight pigs were used to compare the feeding value of barley which had been stored dry, and then hammer-milled, with that of barley stored moist, either anaerobically or treated with 1·3% propionic acid, and then rolled. The pigs were fed from 30 kg live weight for a period of 11 weeks and during this period all consumed the same allowance of dry matter. The growth rate and feed conversion ratio of the pigs given the rolled moist barley were significantly poorer than those of others given dry milled or acid treated rolled barley. There were no treatment differences in carcass attributes.

Microbiological counts made throughout the experiment showed that there was no significant fungal or bacterial development on the acid treated barley. Similar numbers of bacteria were present on the dry barley as on the moist, but the fungal count for the moist grain was always at least 500 times higher than that of the corresponding dry sample. The dominant organisms were identified.

In a further experiment the apparent digestibility of dry matter and nitrogen of diets containing dry, moist or propionic acid treated barley, processed either by milling or rolling, were determined. The highest values were obtained for dry barley. Acid treated moist barley had lower values than moist barley. The method of processing did not affect the apparent digestibility of the dry matter, but that of the N was significantly lower for the rolled barleys.
Rearing of dairy cattle 2. Weaning calves according to their concentrate intake
Authors: Leaver J. D. , Yarrow N. H.
Published: September 2010

British Friesian dairy female calves were offered once daily either 320 or 480 g of milk substitute reconstituted in warm water. Weaning took place when calves were consistently eating 400, 650 or 900 g/day of concentrates. The number of days taken to reach weaning was greater with calves offered 480 g than with calves offered 320 g of milk substitute per day. Calves with a high initial live weight achieved the required concentrate intake and were therefore weaned sooner than smaller calves. A fall in energy intake occurred immediately after weaning and this was greatest in calves previously offered 480 g/day of milk substitute. The treatments had no significant effect on the total intake of concentrates and hay over the 8 weeks of the experiment. Increasing the amount of milk substitute from 320 to 480 g/day increased total feed costs, and feed costs per kg live-weight gain. Increasing the required level of concentrate intake at weaning also increased total feed costs and feed costs/kg live-weight gain, but to a lesser extent. The results suggest that it is preferable to feed dairy replacement calves only 320 g of milk substitute in a once-daily feeding system. Weaning can be successfully under-taken when the calves are consistently eating 400 g/day of concentrates.
The influence of a bio-active feed supplement (hormonexa) on the performance of beef cattle
Authors: Laird R. , Walker-Love J. , Dickson I. A.
Published: September 2010

1. Hormonexa, a bio-active feed supplement, was included at the rate of 3·1 kg per 1000 kg of the concentrate ration for finishing Hereford · Ayrshire steers.

2. Live-weight gain and food conversion were unaffected by the addition of Hormonexa.

3. The killing-out percentage of the supplemented animals was significantly lower and their carcass quality was slightly, but not significantly, lower than that of the control animals.
Growth and lifetime production of scottish blackface hill ewes in relation to the level of feeding during rearing
Authors: Gunn R. G.
Published: September 2010

A study was made of the effects of different levels of nutrition between 3 and 6 months and between 6 and 12 months of age on subsequent growth to mature size, longevity and lifetime production of Scottish Blackface female sheep on a hill farm. Treatment differences between 3 and 6 months were small and resulted in only a 3 kg live-weight advantage for the animals receiving a high level of feeding. Treatment differences between 6 and 12 months were considerable and resulted in a mean 14 kg advantage for animals receiving a high level of feeding. Those animals remained significantly heavier until 42 months of age and significantly larger, as depicted by skeletal measurements, until 54 months of age.

A high level of feeding between 3 and 6 months of age had no significant long-term effect on wool growth ewe survival or lifetime lamb production, whereas a high level of feeding between 6 and 12 months of age had a significant positive effect on the mean number of lambs born per ewe over five lamb crops. This effect was not maintained to weaning, due to an apparently greater lamb mortality. Treatment effects on ewe survival and on flock lifetime production, although considerable, were not statistically different.

It is concluded that any advantages of improved feeding during rearing were largely lost through the inadequacy of the adult nutritional environment and only when the latter was not limiting would higher standards of rearing be justified.
A note on the effect of tail-tying on the reproductive performance of Welsh Mountain ewes
Authors: Newton J. E. , Betts J. E.
Published: September 2010

In a Welsh Mountain flock of 104 ewes, 51 had their tails tied aside for the duration of one oestrus. Tail-tying significantly increased the conception rate at this oestrus. It also significantly increased the mean litter size of ewes superovulated with 1000IU PMSG from 1·70 to 2·33. It is suggested that the most likely reason for this increase in the number of multiple births was an increased number of ejaculations per oestrus. Perinatal mortality was high in lambs from multiple births. The effect of PMSG and tail-tying was to increase the lambing percentage from 77 to 120.