bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of short-term undernutrition and adrenocortical stimulation on wool growth
Authors: Thwaites C. J.
Published: September 2010

Seven daily doses of 60 or 120 mg cortisol administered to mature sheep given a maintenance ration depressed wool fibre diameter by approximately 10%. Similar treatment with 120 mg cortisol for 14 days produced a more severe and prolonged effect, though fibre diameter was unaffected by a series of seven injections of 40 IU ACTH given every second day.

Fourteen days at 10% of maintenance and 14 days' cortisol treatment were applied to mature sheep fed either continually at 150% maintenance, or at 75% followed by 150% maintenance. Cortisol treatment was associated with a significant reduction in fibre diameter only in the animals fed at 150% maintenance. Restriction to 10% maintenance for 14 days had no such effect. Approximately 20% of fibres were shed following cortisol treatment in both nutritional groups, but a marked ‘break’ in the fleece occurred only in the 75% maintenance group.

A low plane of nutrition is confirmed as a major factor predisposing to ‘tenderness’ and ‘break’, and short-term adrenocortical stimulation is shown to be sufficient to produce the reduction in fibre diameter and increased fibre shedding associated with these faults. However, semi-starvation (represented by restriction to 10% of maintenance) appears to have played a relatively minor role in their development.
Estimates of combining abilities and maternal influence in crosses between Merino, Ossimi and Barki sheep
Authors: Galal E. Salah E. , Aboul-Naga A. , Eltawil E. A. , Khishin E. S.
Published: September 2010

A total of 523 lambing records were used to study general combining ability (g.c.a.), maternal ability and specific combining ability (s.c.a.) for three breeds of sheep, the native Ossimi and Barki and the Fleisch Merino. All possible combinations along with the pure breeds were represented. Traits studied were: birth, weaning (4-months) and yearling body weights; lamb survival at weaning; fleece weight and staple length.

Ossimi showed the highest g.c.a. estimates for all traits except birth weight and fleece weight where Merino was the best, and survival where Barki was the best. Barki showed the worst g.c.a. in all traits except survival and staple length for which Merino had the lowest estimates.

Barki exhibited the best maternal ability in weaning and yearling body weights and lamb survival, while Ossimi was best in the other traits. Merino was consistently worst in maternal ability. The two native breeds interacted more favourably with each other than with Merino in lamb production traits. Among the purebred lambs, the Ossimis performed the best in all traits except fleece weight where they were excelled by the Merinos. It was concluded that for marketing weights (i.e. weaning and yearling) and especially when viewed with respect to survival, the Ossimi × Barki cross offers the highest production; while for fleece weight the Merino × Ossimi is the best.
Intensive beef production 13. Replacement of concentrates with root crops
Authors: Kay M. , Macdearmid A. , Massie R.
Published: September 2010

1. Two growth trials and a digestibility trial were carried out with a total of 84 British Friesian steers to investigate the substitution of root crops for a part of the concentrates in an all-concentrate diet. In Trial 1 six experimental diets were offered ad libitum and contained, on a dry-matter basis, (1) 100% concentrates, (2) 34%, (3) 66%, (4) 87% sliced swedes and (5) 66%, (6) 87% whole potatoes. In Trial 2, five diets were offered ad libitum and contained (1) 100% concentrates or (2) 34%, (3) 50%, (4) 66%, (5) 100% swedes.

2. In both the growth trials when the steers weighed less than 350 kg live weight, daily dry-matter intake was lower for steers offered the highest proportion of swedes than for steers offered concentrates. Substitution of potatoes for concentrates resulted in a higher daily dry-matter intake and daily live-weight gain than did substitution of swedes.

3. In Trials 1 and 2 rate of live-weight gain and in Trial 2 carcass gain were similar for steers on treatments 1 and 2. In Trial 2 liveweight gain declined from 1-05 to 0-87 kg/day and carcass gain declined from 0-62 to 0-51 kg/day between steers on treatments 1 and 5. 4. The replacement of concentrates with swedes or potatoes did not affect the overall digestibility of dry matter.
A note on the association between transferrin types and production traits in Indian sheep
Authors: Arora C. L. , Acharya R. M.
Published: September 2010

An investigation of the association of transferrin types with body weights at birth, 3, 6,12 months and first 6-monthly wool yield in Indian sheep showed that variation among transferrin types was a significant source of variation only for yearling weight. Sheep of Tf MB type had the highest yearling weight followed closely by Tf EC. Highest birth weight was recorded in sheep with Tf EM whereas 3-month weight was highest in sheep of Tf EE type. Tf EM sheep had the highest 6-month weight and fleece weight.
The effects of environmental temperature and feeding pattern on the performance of artificially-reared lambs fed cold milk substitute
Authors: Gibb M. J. , Penning P. D.
Published: September 2010

An experiment was carried out using lambs reared from 1 day to 23 days of age on milk substitute given either ad libitum or at a restricted rate of 250 g dry matter per day, in rooms maintained at three temperatures, 7, 14 and 21°C.

Lambs fed milk substitute ad libitum showed similar growth rates (about 365 g per day) at all environmental air temperatures. Total dry-matter intake of milk substitute per lamb over 22 days was slightly higher in those kept in an environmental air temperature of 7°C. The efficiency of lambs in the 7°C environment was lower than those in the 14 and 21°C environments.

When dry-matter intake was held constant, at the restricted level, growth rate increased linearly between 237 and 265 g per day as the environmental air temperature was increased.

At each of these temperature levels the restricted-rate lambs were more efficient than the respective lambs fed ad libitum.
Protein utilization and performance of early-weaned lambs
Authors: Ørskov E. R. , Davies P. J. , Dickson I. A. , Humphries A. B. , Rutter W. , Treacher T. T.
Published: September 2010

1. Groups of 12 male and 12 female lambs, early weaned and individually fed, were used at six centres in Great Britain to determine the effect of dietary protein concentration on growth rate and feed utilization from weaning to 37 kg live weight. Three diets varying in the proportion of rolled barley to white-fish meal were used to give 13·5, 16·0 or 18·5% crude protein in the dry matter. The diets were pelleted and offered ad libitum.

2. The male lambs showed significantly poorer growth rates and feed conversions on the low-protein than on the other diets. Results for the females were more variable so that although the mean values showed similar trends these were not statistically significant.

3. Female lambs had about 19% lower growth rates than male lambs. The mean food conversion (kg dry matter/kg gain) with the diet containing 16% crude protein was 2·67 for the males and 3·30 for the female lambs. Food utilization differed significantly between centres, the centres using lambs of Finn Dorset breeding having lower growth rates and poorer food utilization than Suffolk crosses.
A note on rate of eating in sheep
Authors: Forbes J. M. , Wright J. A. , Bannister A.
Published: September 2010

Sheep ate significantly faster during the first 30 min after being offered fresh food when they were fed on ground, pelleted dried grass than when fed on long hay; chopped dried grass was eaten at an intermediate speed. Rate of eating of the unground diets was negatively related to mean retention time and positively related to total voluntary intake.

In a second experiment, rate of eating during the 30 min after feeding was significantly faster when hay was fed at two-thirds of the ad libitum rate than when it was fed ad libitum, irrespective of whether penning was individual or in groups of six.
Studies in sow reproduction 1. The effect of nutrition between weaning and remating on the reproductive performance of primiparous sows
Authors: Brooks P. H. , Cole D. J. A.
Published: September 2010

Following weaning of their first litter at 42 days post partum, 36 Landrace × (Landrace × Large White) sows were fasted for 24 hr then allocated to one of three feed levels, 1·8, 2·7 and 3·6 kg food/day, until the day after mating. During pregnancy all the sows received 1·8 kg food/day.

The incidence of infertility and anoestrus was greatest for sows fed 1·8 kg/day and least for sows fed 3·6 kg·day. Sows fed 1·8 kg/day took significantly (P < 0·01) longer (21·6 + 3·0 days) to return to oestrus than sows fed 3·6 kg/day (9·2 ± 2·2 days). The mean litter size for sows fed 1·8, 2·7 and 3·6 kg food/day was 9·4 ± 0·9, 10·1 ± 0·8 and 11·5 ± 0·6 piglets respectively, but these differences were not significant.
The effect of a methane-suppressing compound, trichloroethyl adipate, on rumen fermentation and the growth of sheep
Authors: Clapperton J. L.
Published: September 2010

1. Three experiments have been carried out to study the effect of adding trichloroethyl adipate, a compound known to prevent the production of methane bothin vitroandin vivo, to the diet of sheep on fermentation in the rumen and on the growth of lambs. In Experiment 1 the additive was incorporated at various levels for 6 weeks, in Experiment 2 it was given at one of four levels for 12 weeks and in Experiment 3 it was included in the food of growing lambs for 15 weeks.

2. Initially, in Experiments 1 and 2, the additive caused a large reduction in methane production and in the molar proportion of acetic acid in the rumen liquor with a corresponding increase in propionic acid. These effects were much reduced after the first 2 to 3 weeks of administration.

3. The total food intake of the animals receiving the additive in Experiment 3 was 4% less than that of the control animals. This difference was negligible at the start of the experiment but increased throughout the feeding period.

4. On average, the relative live-weight gain and the changes in the weights of carcass, viscera and empty body weight of the animals receiving the additive were also 4% less than those of the control animals.

5. The observed differences in weight gain resulted from the differences in food intake and the additive had no beneficial effect upon lamb growth. This lack of effect on growth was due to rapid adaptation by the rumen fermentation to the presence of the additive.
A note on the use of brewers' dried grains as a protein feedstuff for cattle
Authors: Öster A. , Thomke S. , Gyllang H.
Published: September 2010

Young, uncastrated male cattle (initial weight 80 kg, final weight 240 kg) were used to evaluate brewers' dried grains as a protein source (17 or 36% of the concentrate mixture), in comparison with soyabean oil meal (6% of the concentrate mixture). There were no significant effects on feed intake or average daily live-weight gain. The killing-out percentages for the three treatments were 49·2; 48·6 and 46·9 respectively (P < 0·001). There was a lower fat deposition (P < 0·01) in animals receiving the higher level of brewers' dried grains, and the degree of rumen parakeratosis was less (P < 0·001) with the diets containing grains.
Protein metabolism of rats treated with trienbolone acetate
Authors: Vernon B. G. , Buttery P. J.
Published: September 2010

(1) Both the anabolic agent trienbolone acetate (3-oxo-17-β-hydroxy- 4,9,11-estratriene acetate) and testosterone subcutaneously injected into entire female rats caused an increase in growth rate compared with placebo controls (P<0·01 andP<0·001 respectively). The trienbolone acetate rats grew slower than the testosterone-treated animals (P< 0·01). This may reflect differences in the mode of action of the steroids.

(2) In castrate males there were no significant differences in growth rate between the trienbolone acetate, testosterone or placebo control rats (P>0·05).

(3) Trienbolone acetate reduced the rate of myofibrillar protein degradation in female rats, within 3 days of treatment, at least as judged by Nt-methylhistidine excretion. The treated rats had superior nitrogen retentions (P<0·01) and feed conversions (P< 0·001).

(4) The data suggest that the rat is a suitable model on which to test the mode of action of trienbolone acetate.
Anorexigenic substances and voluntary food intake in the pig
Authors: Wyllie D. , Owen J. B.
Published: September 2010

The urine of pigs contains a substance with an anorexigenic effect when injected into pigs or rats. When injected into rats or pigs onad libitumfeeding a urine extract caused a reduction in food intake only when the extract had been obtained from the urine of satiated pigs, and not from hungry pigs. The pig urinary anorexigen there-fore appears to be similar in nature to the anorexigen extracted from rat urine. Like rat urinary anorexigen, its anorexigenic effect is largely dose dependent and it is soluble in distilled water. Rats injected with plasma from satiated pigs showed an anorexigenic reaction but injection of plasma from hungry pigs had no effect on food intake. The possible role of these anorexigenic substances in the control of voluntary food intake in the pig is discussed.
The effect of daylength on the growth of lambs. 1. Comparisons of sex, level of feeding, shearing and breed of sire
Authors: Forbes J. M. , El Shahat A. A. , Jones R. , Duncan J. G. S. , Boaz T. G.
Published: September 2010

Two experiments were carried out with crossbred lambs which had been weaned in July when 16 weeks old. From early September they were kept in a light-proof building with 12 h artificial light per day for 3 weeks and then half were exposed to 16 h and half to 8 h light per day for a further 16 weeks.

Experiment 1 included 72 lambs (48 castrated males and 24 females) and half in each daylength were fed on a concentrated ration ad libitum; the other half were restricted to 70 g/kg live weight0·75 per day. Half of each group were shorn. Lambs kept in 16 h light per day grew significantly faster than those in short daylength at both levels of feeding. Food conversion ratio was best in the 16 h restricted sheep. Unshorn lambs had heavier carcasses than shorn lambs. Long daylength stimulated general growth of the animal without markedly affecting carcass composition, irrespective of level of feeding, whereas ad libitum feeding resulted in much fatter carcasses than did restricted feeding. Gut fill was significantly greater in long-daylength sheep.

Experiment 2 included 24 individually penned castrated male lambs, 12 of which were sired by Suffolk rams and 12 by Oxford rams; all were fed at the restricted level. Long daylength significantly stimulated weight gain, especially in the Oxford-cross lambs, but the increase in carcass weight was not significant in this experiment due to the large effect on gut fill.

It was concluded that long daylength stimulated growth and gut fill by some central control mechanism and not merely by encouraging more eating.
Body composition changes in lactating ewes estimated by serial slaughter and deuterium dilution
Authors: Cowan R. T. , Robinson J. J. , Greenhalgh J. F. D. , McHattie I.
Published: September 2010

Changes in body composition during lactation were measured in 12 Border Leicester × Scottish Blackface ewes by serial slaughter at 12, 41 and 111 days of lactation. Ewes suckled twin lambs and were given daily 1·6 kg dry matter of a complete diet containing 151 g crude protein and 10·2 MJ metabolizable energy/kg dry matter.

Live weights of ewes averaged 60·2, 58·9 and 55·8 kg at 12, 41 and 111 days of lactation respectively. There were no significant changes in weights of stomach, small and large intestine and liver.

The weight of body fat averaged 9·19, 2·28 and 1·19 kg at 12, 41 and 111 days respectively (P < 0·001) and weight of ash increased from 1·72 kg at 12 days to 2·30 kg at 111 days (P < 0·001). Water to protein ratios at the three stages of lactation were 2·94, 3·36 and 3·18 (P < 0·10). The energy value of weight loss varied from 68 to 17 MJ/kg, depending on the relative changes in total body water and fat. Live-weight change was therefore a poor indicator of change in body energy during early lactation.

Body fat could be predicted from its combined relationships with live weight and total body water (residual s.d. ±0·70 kg), but when deuterium oxide space was used to estimate body water separate equations were necessary for early and later stages of lactation. This was apparently due to differences between stages of lactation in the time required for deuterium oxide to equilibrate with water in the reticulo-rumen.
Double-low rapeseed meal for pigs: ileal apparent digestibility of amino acids in diets containing various proportions of rapeseed meal, fish meal and soya-bean meal
Authors: Partridge I. G. , Low A. G. , Matte J. J.
Published: September 2010

In order to determine the relative nutritional value of rapeseed meal (var. Tandem) in comparison with soya-bean meal and fish meal, seven barley-based diets were formulated to provide 13·1 MJ digestible energy and 8·8 g total lysine per kg. They contained soya-bean meal (S), rapeseed meal (R) or fish meal (F) alone, or equal proportions (on a total nitrogen basis) of soya and rapeseed, soya and fish meal, rapeseed and fish meal or soya, rapeseed and fish meal. The study involved 14 pigs growing from 40 to 90 kg, each fitted with a T cannula in the terminal ileum. Dietary treatments were applied during 7-day periods according to a 7 × 7 Latin-square design, replicated twice. The pigs were fed at 12-h intervals. Ileal digesta were collected during two 12-h periods from each pig after adaptation to each diet. Nutrient apparent digestibilities were measured using chromium III oxide as a marker; for diets S, R and F, respectively, values were: dry matter, 0·58, 0·51 and 0·66 (s.e. 0·014); N, 0·72, 0·67 and 0·73 (s.e. 0·011); lysine, 0·79, 0·72 and 0·83 (s.e. 0·010), with a similar relationship between diets for most other amino acids. In general, values for diets containing combinations of the protein supplements were intermediate between those for diets containing the respective single supplements. Following the main trial, seven pigs were given a semi-purified diet containing rapeseed meal as the only protein source; this gave amino acid digestibility values similar to or slightly higher than diet R. Diet R, which contained 375 g rapeseed meal per kg, presented no palatability problem. Rapeseed meal of the quality used in this trial could contribute a substantial proportion of the protein supplement for growing pigs. Its value should be enhanced by formulating diets according to the ileal digestibility of the limiting amino acids.
A note on the effects of health environment on heterosis for growth rate in pigs
Authors: Kennedy B. W. , Quinton M.
Published: September 2010

Heterosis for growth rate in pigs is usually expressed, and reviews of European and North American studies have been given by Sellier (1976) and Johnson (1981). Kennedy and Moxley (1980) observed heterosis of 0·044 to 0·067 for weight at 154 days and attributed some of the crossbred advantage to heterosis for resistance to atrophic rhinitis. Similarly, McGuirk, Bourke and Manwaring (1978) attributed some of the heterosis for growth rate in sheep to heterosis for resistance to pneumonia. Although little attention has been paid to interactions between heterosis and health environment, Barlow (1981) concluded from an extensive review of studies involving farm and laboratory animals that heterosis is environment dependent and is enhanced by increased stress. Sellier (1976) commented that it would be useful to examine the degree of heterosis with ‘specific pathogen free’ pigs raised in a healthy environment, and this study examined heterosis for days to 90 kg in Yorkshire × Landrace pigs under three different environments with respect to health conditions.
Influences of production circumstances on the economic revenue of cattle breeding programmes
Authors: Groen A. F.
Published: September 2010

The economic values of cattle production traits differ with different production circumstances. This sensitivity implies that (1) production circumstances influence the revenue of breeding programmes, and (2) losses in revenue of breeding programmes occur when circumstances used in defining breeding goals are incorrect with regard to actual production circumstances at the moments of expression of genetic superiorities. In this study, these effects are quantified for a set of genotype and index traits, including milk production traits, food intake capacity and live weight. Twenty-four situations of production circumstances were studied, including alternative output limitations, milk production levels, roughage qualities and product (milk, beef) and production-factor (food) prices.

Results indicate that type of output limitation is the most important factor in determining revenue. Also, incorrect prediction of type of limitation leads to highest losses in revenue found (proportionately 0·01 to 0·06 of revenue). Losses in revenue due to incorrect prediction of production circumstances seem too low to justify complete diversification of cattle breeding goals within a breeding organization, except for different types of output limitations.
The direct and maternal components of the response to divergent selection for yearling growth rate in angus cattle
Authors: Herd R. M.
Published: September 2010

A crossmothering experiment was conducted to measure the direct and the maternal components of the response to divergent selection for yearling growth rate in beef cattle. The animals were from three closed lines of Angus cattle. Two lines had been selected since 1974 for either high (high-line) or low (low-line) average daily gain from birth to yearling, and the third line was maintained as a randomly bred control-line. A total of 221 female calves born between 1984 and 1987 was used in the crossmothering experiment, and an additional 113 cows bearing calves in 1988 were used to obtain more records of milk production.

On average, high-line calves born in 1984-87 were 45 kg heavier at weaning (200 days of age) than low-line calves and 65 kg heavier at yearling age, corresponding to a proportional divergence in daily weight gain of 0·29 and 0·32 respectively. The direct component of the response to selection was 0·82 (s.e. 0-05) of the divergence in body weight at weaning and 0·89 (s.e. 0·05) at yearling age. The maternal component was 0·18 (s.e. 0·06) and 0·11 (s.e. 0·04) for weaning and yearling weight respectively. Over the years 1984-88, high-line dams produced 1·15 times the milk of low-line dams and only 1·03 times that of control-line dams. There were small differences in the composition of milk sampled in 1984 which resulted in the milk of high-line dams having a higher content of metabolizable energy (ME) than that of control-line dams. The ME in the milk consumed by the calves from the three selection lines was sufficient to fuel similar proportions of their pre-weaning growth and indicated that the expression of the maternal component of the selection response may be via small differences in the quantity and quality of the milk produced by the dams. Expression of the direct component appeared to be at least partially via differences in appetite of the calves. These results, together with results for sheep, mice and rats, show that the direct component of the response to selection for growth is much larger than the maternal component.
Hormonal induction of twinning in farmed red deer (Cervus elaphus): comparative mortality and growth of twins and singles to weaning
Authors: Fennessy P. F. , Moore G. H. , Littlejohn R. P.
Published: September 2010

Multiple births were induced in 20 hinds subjected to a progesterone plus gonadotropin treatment to advance the breeding season by about 4 to 5 weeks. In total, over 2 years, 92 hinds were treated and run with melatonin-treated stags. Of the 59 hinds that calved to the induced oestrus, 39 produced single calves, 19 produced twins and one produced triplets. Birth weight, gestation length, perinatal mortality and growth rate to weaning at ca. 20 weeks of age were compared for singles and twins. There was a significant effect of birth type on birth weight with twins being proportionately 0·30 lighter than singles (6·27 and 8-94 kg; P < 0·001), with a significant interaction between the birth weight of a calf and the sex of its co-twin (P < 0·05); males born as co-twins to females were proportionately 0·18 heavier than their co-twin females (P < 0·06), while in contrast twin male sets were substantially lighter than twin female sets. Gestation lengths were similar for both singles and twins, with significant negative relationships between gestation length and birth weight for both singles and twins, with a 2-day decrease in gestation length for a 1-kg increase in mean birth weight. There was a strong quadratic relationship between perinatal survival and birth weight; the expected mortality rates at 5, 8 and 11 kg birth weight derived from the relationship were 0·39, 0·11 and 0·39 respectively, indicating reduced probability of survival at both low and high birth weights. The regression relationships between weaning weight or growth rate to weaning and birth weight indicate that at the same birth weight, twin-reared calves were about 5 kg lighter than singles at 20 weeks, while an extra 1 kg weight at birth was associated with an extra 2 kg weight at 20 weeks.
Resumption of post-partum oestrous behaviour and associated plasma progesterone profiles in Menz ewes
Authors: Mukasa-Mugerwa E. , Ezaz Zere
Published: September 2010

Fifty Ethiopian Menz ewes maintained on pasture grazing with uncontrolled mating showed ovarian cyclicity at all times of the year. Conception rates to first, second and third service were 78, 18 and 4%, respectively. Mean post-partum anoestrous interval was 76·1 (s.e. 4·6) days. Two-thirds of ewes conceived before lamb weaning at 90 days and had 8 month lambing intervals. Twice weekly progesterone determinations showed that 67% of ewes exhibited a silent ovulation 66·4 (s.e. 10·5) days post partum, 12% of oestrous cycles were longer than 20 days and 8% of heats were false or anovulatory. It was concluded that Menz ewes have the natural potential for three lambings in 2 years, under adequate nutrition. Their better management and genetic improvement should further reduce current lambing intervals and increase annual reproductive rates.
Influence of season on testicle size and libido in male goats from the Mediterranean area
Authors: Roca J. , Martinez E. , Vazquez J. M. , Ruiz S. , Coy P.
Published: September 2010

In the Mediterranean environment and subtropical microclimate of the south-east Iberian Peninsula (37° 59' N), testicle size and sexual behaviour of male goats were studied and the influence of season (day length, air temperature and relative humidity) on these factors examined.

Nine, 13-month-old Murciano-Granadina male goats weighing 47 to 53 kg were used. The experiment began during the month of January and extended for a complete year. Every 2 weeks, anterior-posterior maximum testis diameter was measured. They were tested twice a week for levels of sexual behaviour using ovariectomized goats and libido was evaluated as reaction time to mating.

The annual mean testis diameter was 5·06 (s.e. 0·02) cm, varying significantly with season of the year. The lowest values were measured during winter 4·89 (s.e. 0·03) cm. These increased (P <0·01) in spring (5·16 (s.e. 0·01) cm) and summer (5·19 (s.e. 0·02) cm), but decreased again (P <0·01) in the autumn (5·04 (s.e. 0·02) cm). The annual mean reaction time was 197 (s.e. 12) s, but was longest (P <0·01) in spring (318 (s.e. 30) s), and shortest during summer (144 (s.e. 16) s) and autumn (132 (s.e. 17) s). The testicle diameter measurement was correlated with day length (r = 0·41; P <0·01) and air temperature (r = 0·45; P<0·01), while the reaction time showed no relationship with climatic measurements.

It was concluded that day length is not the only factor responsible for seasonal variation in testis size of Murciano-Granadina male goats and that, in their natural habitat, libido is unlikely to be a limiting factor in the breeding programme.
A comparison of phase feeding and choice feeding as methods of meeting the amino acid requirements of growing pigs
Authors: Bradford M. M. V. , Gous R. M.
Published: September 2010

Two experiments are reported in which a comparison was made of phase feeding and choice feeding as methods of meeting the changing amino acid requirements of growing pigs. In the first experiment, three feeding strategies were used: a system in which a single food (165 g protein per kg food) was offered throughout the growth period; a phase-feeding system, using five different treatments; and three choice-feeding treatments, in which the two diets offered differed only in their protein concentrations. The second experiment consisted of six treatments, three of which constituted a single feeding system, being a high, a medium, (the control) and a low protein food (240, 165 and 100 g protein per kg); there were two phase-feeding treatments, of three and five phases; and one treatment in which a choice was offered of the high and the low protein foods. In both experiments, group data were collected on Landrace × Large White pigs, sexes separate, during the growing period (30 to 90 kg). All pigs were weighed weekly, as was the amount of food consumed in each pen of 10 animals. Phase feeding improved food conversion efficiency (+4·4 g/kg) and caused a decline in both food intake (−45·3 g) and P2 backfat thickness (−0·4 mm) with each increment in the number of phases used. Results of the choice feeding treatments were not statistically significantly different from either the control or the phase feeding treatments. The intake of dietary protein was higher in the choice treatments than in the control (420 v. 370 g in experiment 1 and 345 v. 334 g in experiment 2). Where the two foods on offer differed only in protein content, pigs reduced the proportion of high protein food in the combination chosen by 0037 and 0·059 per week in the two experiments respectively, these linear trends being statistically highly significant. They were less successful in differentiating between the high protein food and maize, the proportion of high protein food chosen decreasing at a statistically significant rate of 0018 per week, but where the maize had not been supplemented with vitamins and minerals there was no significant trend in the way in which the pigs selected their diet, demonstrating the importance of the correct design of the two foods on offer in a choice-feeding programme.
The effect of semen collection frequency and food intake on semen production in breeding boars
Authors: Kemp B. , Barker G. C. M. , Hartog L. A. den , Verstegen M. W. A.
Published: September 2010

An experiment was conducted to study the effect of feeding level and semen collection frequency on semen quantity and quality of 62 Yorkshire boars at two artificial insemination centres during 10 successive periods of 2 weeks. The experiment had a 2 × 2 factorial design with two feeding levels (2·75 and 3·5 kg/day) and two semen collection frequencies (three and five times in 2 weeks).

In the first 2-week period boars on the high frequency semen collection scheme produced 94 × 109 sperm cells more than boars on the low scheme. In periods 2 to 10 the mean difference was only 18 × 109 sperm cells. Boars on the high feeding level produced 32 × 109 sperm cells more per 2-week period than the boars on the low feeding level (P < 0·05). Boars at the high collection frequency and the high feeding level tended to produce a higher number of sperm cells during periods 2 to 10 than the boars on the high semen collection frequency and the low feeding level (P > 0·05). No effects of food intake or semen collection frequency on semen quality were found.
Angora rabbit wool production: non-genetic factors affecting quantity and quality of wool
Authors: de Rochambeau H. , Thébault R. G. , Grun J.
Published: September 2010

A study was made of the wool production of 490 females and 137 males of a strain of French Angora rabbit. The female adults weighed 4107 g and produced 249 g of wool every 14 weeks. Production was low for the first harvest (35 g) which consisted mainly of short wool. It then increased rapidly (203 g for the third harvest). After the third harvest, three-quarters of long wool was also bristly. The length of bristles (102 mm) decreased by 4 mm, and that of downs (62 mm) increased by 3 mm when the harvest number went from two to four. The coefficient of correlation between wool production and live weight was lower than 0·30. Adult females born in autumn produced 16 g more than those born in summer. Wool production was at a maximum during autumn and winter harvests and at a minimum in summer.

Winter fleeces had longer bristles and down than summer ones. Males produced well wool than females. When a female dropped a litter, her wool production decreases by proportionately 0·1 to 0·2. Bristly fleeces were clearly different from woolly fleeces on account of higher weight, homogeneity and compression. Objective criteria to evaluate tautness will have to found.
A note on the influence of climatic variables and age on the response of beef calves to different housing types
Authors: Kubisch H.-M. , Makarechian M. , Arthur P. F.
Published: September 2010

The response of 376 weaned bull calves to two different housing types was studied in a 2-year feedlot trial. Overall, animals with shelter had a higher rate of gain than animals with no shelter. The difference in the rate of gain between the housing types was, however, restricted to the coldest periods. No significant interaction between housing type and age of calf was observed. Regression analyses showed that whilst average daily temperature appeared to have a negligible effect on growth, temperature fluctuations between weighing days appeared to affect growth of calves in both housing types. Overall, climatic variables contributed more to the variance in gain of calves with shelter than of calves with no shelter.
Genetic and phenotypic parameters for yield, food intake, and efficiency of dairy cows fed ad libitum 2. Estimates for part lactation measures and their relationship with ‘total’ lactation measures
Authors: Persaud P. , Simm G.
Published: September 2010

Records on fat plus protein yield, food intake and food efficiency up to 26 and 38 weeks of lactation, were obtained from dairy cows fed ad libitum in the Edinburgh School of Agriculture's Langhill herd. After discarding the first 2 weeks data, the records were divided into successive 6-week periods. Restricted maximum likelihood analyses were carried out on each period for each trait, fitting an animal model, with repeat lactations as an additional random effect. Univariate analyses were done after approximate canonical transformation of the data. Heritability estimates for 6-week fat plus protein yield, food intake and efficiency, from the 38-week lactation data, ranged from 0·08 (s.e. 0·10) to 0·17 (s.e. 0·12), 0·15 (s.e. 0·09) to 0·49 (s.e. 0·15) and 0·08 (s.e. 0·14) to 0·25 (s.e. 0·11), respectively. Generally, lower heritabilities were obtained for earlier part measures of fat plus protein yield and efficiency and for later part measures of food intake. Genetic correlations between part measures and ‘total’ lactation fat plus protein yield, food intake, and efficiency ranged from 0·82 to 100, 0·85 to 0·98, and 0·60 to 1·00, respectively. Corresponding phenotypic correlations ranged from 0·76 to 0·94, 0·68 to 0·87, and 0·73 to 0·89, respectively. The correlations were lowest for the first 6-week period then gradually increased up to a maximum in the third or fourth periods and declined thereafter. The results indicate that selection on a part measure of food intake or efficiency, taken between 15 to 20 weeks of lactation, will be equally effective in improving intake and efficiency compared with selection on total lactation measures. Other 6-week measures taken between weeks 9 to 14 and 21 to 26 will also give good prediction of total lactation intake and efficiency.
The effect of dietary nutrient density on growth in the pig
Authors: Lawrence T. L. J.
Published: September 2010

Forty-eight Large White ♂× (Landrace × Large White) ♀ male castrate pigs were individually fed, on a live-weight-based scale between approximately 23 kg and 88 kg live weight, similar daily in-takes of digestible energy, crude protein and total lysine from four diets (12 pigs per diet) of widely differing compositions and nutrient densities. The digestible energy contents (MJ/kg) (1), crude protein (%) (2) and total lysine (%) (3) contents of the diets were: diet A (1) 11·40, (2) 14·40, (3) 0·82; diet B (1) 12·90, (2) 16·50, (3) 0·94; diet C (1) 14·96, (2) 19·20, (3) 1·09 and diet D (1) 18·28, (2) 23·30, (3) 1·32. To give the required daily nutrient intakes, relative to diet A (100) the intakes of diets B, C and D were 87·5, 75·0 and 62·5 respectively. Growth rates, carcass weights (from dissimilar but non-significantly different slaughter weights), killing-out percentages and the digestible energy required to produce a unit of carcass improved progressively from diet A to diet D. In these variables the significant differences tended to lie between diets A and B on the one hand compared with diets C and D on the other. The weights of lean tissue dissected from the carcass were similar for all pigs. The weights of dissected fatty tissue and backfat thicknesses increased from diet B to C to D but only the differences between diets B and D were statistically significant.
The use of heat transfer coefficients in estimating sensible heat loss from the pig
Authors: Mount L. E.
Published: September 2010

Heat transfer coefficients are used to calculate convective and radiant heat losses from pigs of 4, 20 and 60 kg body weight at 20 and 30 °C environmental temperatures for different wind speeds. Comparisons with heat losses estimated from whole-animal calorimetry suggest that calculations with heat transfer coefficients can lead to useful approximate estimates of heat loss from the pig.
The effect of pregnancy, energy intake and mating weight on protein deposition and energy retention of female pigs
Authors: Hovell F. D. Deb , MacPherson R. M. , Crofts R. M. J. , Smart R. I.
Published: September 2010

1. In a comparative slaughter experiment, 12 female pigs (six at 80 kg and six at 100 kg) were allocated at first oestrus to each of five treatments: Treatment 1 initial slaughter, or Treatments 2, 3 and 4 mated and given 19·5, 25·8 or 32·1 MJ ME/day for the last 100 days of pregnancy, or Treatment 5 not mated (virgin) and given 25·8 MJ ME/day over a similar period. Pigs on Treatments 2, 3, 4 and 5 were given the same amount of protein and were killed about 123 days after first oestrus. Piglets were removed at birth.

2. Total protein deposition (carcass+viscera+piglets) was increased from a total (±SE) of 5·50 to 8·47 (±0·43) kg as ME intake was increased from 19·5 to 32·1 MJ ME/day. About 75% of the increase in protein deposition was in the carcass component. The average response to ME was 2·2 ± 0·58 g total protein deposition per MJ increment in ME.

3. The once-mated pigs deposited similar amounts of total protein to the virgin pigs but significantly less (P<0·05) carcass protein, when this was corrected to the same amount of carcass fat deposition.

4. Increasing energy intake from 19·5 to 32·1 MJ ME/day increased total fat deposition from 2·8 to 16·0 kg. The average response to ME was 13·5 ± 1·53 g fat deposited per MJ increment in ME.

5. There were no significant differences between the once-mated and virgin pigs in their calculated maintenance requirement, nor in the efficiency with which ME surplus to requirement for maintenance was utilized for energy retention. The average maintenance requirement for all pigs was 530 (95% limits 303·882) kJ/kg0·85. day. The average efficiency of utilization of ME for energy retention was 58·5 ± 6·2%.

6. There was no evidence of any pregnancy anabolism other than that involving the conceptus, the needs of the dam specific to pregnancy and preparation for lactation.
Lamb growth performance of Iranian fat-tailed Karakul, Mehraban and Naeini breeds of sheep and their crosses with Corriedale and Targhee rams
Authors: Makarechian M. , Farid A. , Sefidbakht N.
Published: September 2010

Birth weights, weaning weights (75 days of age) and pre-weaning average daily gains of 291 lambs and post-weaning average daily gains, feed conversions and market weights of 136 ram lambs were studied. The lambs were of three fat-tailed Iranian breeds of sheep, Karakul, Mehraban and Naeini, and their crosses with Corriedale and Targhee rams.

The crossbreds were significantly superior to the purebreds in all the traits studied, by approximately 7% in the pre-weaning traits and up to 18·4% in the post-weaning daily gain. Among the purebreds, Mehraban lambs were superior to the other two breeds in the preweaning traits and final weight.

The progeny of the Targhee and Corriedale rams were similar in performance except for feed conversion, in which the lambs sired by Targhee rams were more efficient. Breed of dam had a significant effect on the pre-weaning traits and feed conversion. Mehraban ewes produced lambs with the highest pre-weaning average daily gain and weaning weight among the crossbreds, but they were the least efficient lambs after weaning.

Age of dam significantly influenced the pre-weaning but not the post-weaning traits. Lambs born to 4-yr-old ewes were the heaviest and those born to 2-yr-old ewes were the lightest at birth. The lambs reared by 2-yr-old ewes had significantly lower rates of growth and were the lightest at weaning. Sex had a highly significant effect on the pre-weaning traits in favour of the male lambs.
A note on the growth and carcass quality of Makui and Moghani lambs on different diets
Authors: Nik-Khah A. , Assadi-Moghaddam R.
Published: September 2010

The effects of three diets on the performance and carcass quality of lambs of the Makui and Moghani breeds of sheep were studied. Thirty-two Makui and 33 Moghani lambs, 6 to 7 mo of age, were kept on feedlots and given three diets for 77 days. The diets each contained a barley, alfalfa meal and corn silage base plus different levels of urea, molasses and dried beet pulp.

The average daily live-weight gains (ADG) of lambs fed on diets I (no urea), II (0·8% urea) and III (1·4% urea) were 218, 208 and 204 g respectively, while feed conversion ratios (FCR) were 6·3, 6·6 and 6·8 respectively. The overall ADG for Makui and Moghani lambs were 213·6 and 206·6 g respectively and the FCR were 6·4 and 6·9 respectively. None of these differences was statistically significant. The mean dressing percentages of lambs fed on diets I, II and III were 52·5, 52·7 and 53·9 respectively, and those of Makui (53·1) and Moghani lambs (53·3) were similar. There were only minor differences between the carcass characteristics of the two breeds and these were not influenced by the different diets.
Effects of selection for body size on the weight and cellular structure of seven mouse muscles
Authors: Byrne Ignatius , Hooper J. C. , Mccarthy J. C.
Published: September 2010

The effects of selection for increased and decreased body weight in mice at 5 and at 10 weeks of age on the weight and mean fibre diameter and number of seven different muscles were studied by dissecting and histologically examining animals from large, small and unselected control lines. The purpose was to learn how selection for body size affects muscle weight and its components. Selection for increased body weight significantly increased the weight of m. biceps brachii, m. tibialis anterior, m. pectoralis major, m. brachio-radialis, m. soleus, m. rectus femoris and m. psoas major. These increases in muscle weight reflected increases in both fibre diameter and number although there were a few exceptions. Selection for low body weight produced decreases in the weight of all muscles. These reflected significant reductions in mean fibre diameter and, in most cases, fibre number. Significant estimates of heterosis in mean fibre diameter were obtained in m. biceps brachii and m. tibialis anterior from crosses between the Large and Small lines selected at 5 weeks and also between the lines selected at 10 weeks of age, respectively.
The effect of level and method of feeding milk substitute and housing environment on the performance of calves
Authors: Mitchell C. D. , Broadbent P. J.
Published: September 2010

1. Thirty-six Ayrshire and 48 Friesian male calves were used in two separate experiments to examine the effect of level and method of feeding milk substitute in two different housing environments. The calves were weaned when the daily intake of air-dry, milk substitute plus concentrates per head reached 1·59 kg, provided at least 0·45 kg of this intake was from concentrates.

2. The feeding systems affected the total consumption of milk substitute (P< 0·001) and created differences in live weight at weaning. The housing environments affected the age at weaning (P< 0·001) and the intake of milk substitute (P< 0·001).

3. The extra capital cost involved in a ‘controlled environment’ type of calf house does not appear to be justifiable in terms of calf health or performance when compared with the performance of calves in a ‘climatic’ house in the north-east of Scotland.
A comparison of the Charolais, British Friesian and Hereford breeds as sires of crossbred singlesuckled calves for beef production
Authors: Haycock R. E. , Stewart D. A.
Published: September 2010

In three successive years cows from an Aberdeen Angus cross Shorthorn herd were mated to pedigree Charolais, British Friesian and Hereford bulls. A comparison of the progeny of the three breeds of sire under controlled conditions was therefore possible using a random selection of dams for mating, and identical rearing of the calves. Results for live-weight gain of the suckled progeny were analysed and showed superiority of the Charolais breed over the other two when used in this form of beef cattle production.

For birth weights and daily live-weight gains, particularly during the grazing period, the Charolais cross progeny showed superiority over the other two. There was a consistent although not always statistically significant tendency for these differences between the breed crosses to occur in the male calves only, the females showing little difference between breeds. The data also showed highly significant relationships between gestation period and birth weight, both within and between breed crosses.
The interaction between dietary lipids and fibre in the sheep 1. A comparison of the methods used for crude fibre and acid-detergent fibre estimations
Authors: Devendra C. , Lewis D.
Published: September 2010

A comparison has been made between the methods for crude fibre (CF) and acid-detergent fibre (MADF) determination. In diets containing 10 to 70 % hay with or without 8 % tallow (T) or maize oil (MO), a highly significant (P < 0·001) correlation of r = 0·95 was observed between CF and MADF estimates. This high correlation confirmed a similar relationship found in silages, concentrate feeds and also hays. Similarly for rumen digesta, a correlation of r = 0·93 was found (P < 0·001). The equation for predicting CF from MADF calculated from diets and digesta data together was CF = 0·503+0·848 (+0030) MADF and the residual variation found was sufficiently small to provide useful estimates.