bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of selection for lean growth in Suffolk sires on the saleable meat yield of their crossbred progeny
Authors: Simm G. , Murphy S. V. 
Published: September 2010

AbstractThis experiment involved a commercial evaluation of carcasses of extensively reared crossbred lambs. These were sired by Suffolk rams from either a selection line or a control line of a Scottish Agricultural College (SAC) selection experiment, in which selection wasfor lean growth, or by Suffolk ‘reference sires’ from an industry co-operative breeding scheme (SSRS). The lambs were slaughtered at a target live weight of 42 kg between June and October 1992. In total, 421 lamb carcasses were included in the evaluation, 173 from six selection-line rams, 193 from six control-line rams and 55from three SSRS rams. Each of the carcasses was visually appraised for estimated subcutaneous fat proportion and for conformation of the shoulder, loin and leg, as well as being classified using conventional Meat and Livestock Commission (MLC) scales for fat and conformation. Animals were slaughtered at an average age of 139·5 (s.d. 25·6) days and achieved an average cold carcass weight of 20·04 (s.d. 0·96) kg. Carcasses had an average estimated subcutaneous fat proportion of 122·3 (s.d. 22·4) g/kg — equivalent to MLC fat class 3L to 3H. Overall conformation scores, on a 15-point scale, averaged 8·63 (s.d. 1·80) points. Carcasses were cut into joints according to a leading supermarket specification. The weights of pairs of shoulder, flank, loin and leg joints were obtained for each carcass, as well as weights of bone and fat removed during jointing. Saleable meat weights and proportions averaged 15·31 (s.d. 0·76) kg and 765·9 (s.d. 10·0) g/kg respectively. At a constant carcass weight, the SAC selection-line progeny were significantly younger (-11 days), had a significantly higher carcass value (+£1·50), a significantly lower estimated subcutaneous fat proportion (-13 g/kg), and a significantly higher weight of saleable meat (+0·1 kg) and higher proportion ofsaleable meat (+4 glkg) than control-line progeny, but had lower conformation scores. SSRS progeny had similar growth and fatness to selection-line lambs, but had poorer conformation, and significantly more bone in the carcass than either of the SAC lines. When comparisons were made at a constant estimated subcutaneous fat proportion, all differences in conformation between SAC lines disappeared. However, SSRS progeny remained poorer in conformation. The SSRS rams werefrom afoundation generation of the scheme, and were not expected to be markedly superior for carcass characteristics. Carcass weight was byfar the most important predictor of weight of saleable meat, or leg and loin joint weights. Conformation and estimated fat proportion made only marginal improvements, if any, to the precision of prediction, with fat proportion being the more important of the two predictors.
A comparison of alternative nucleus breeding systems and a sire referencing scheme for sheep improvement
Authors: Roden J. A. 
Published: September 2010

AbstractStochastic simulation was used to compare selection response and rate of inbreeding in four nucleus breeding systems and a sire referencing scheme for sheep: an open nucleus system (ONS), an open nucleus system with sequential selection of the nucleus (ONS-S), a sire referencing scheme (SRS) and a dispersed open nucleus system (DONS). Selection was based on best linear unbiased prediction of breeding values for a single trait measurable on all individuals prior to selection. Selection in a population of 1200 ewes equally divided into 10 flocks was simulated over a 15-year period. The mean rate of genetic gain was proportionately about 0-15 higher in ONS-S and DONS compared with ONS and SRS. The rate of inbreeding in SRS was considerably lower and in ONS-S, considerably higher, than in the other systems. The level of prolificacy in the population did not influence the relative ranking of the breeding systems but may have implications for their optimal structure.
Responses of sheep to annual cycles in nutrition 1. Rôle of endogenous growth hormone during undernutrition
Authors: Adams N. R. , Briegel J. R. , Rigby R. D. G. , Sanders M. R. , Hoskinson R. M. 
Published: September 2010

AbstractPlasma concentrations of growth hormone (GH) are elevated in sheep during undernutrition. The present study attempted to determine whether this increased secretion mediated nutritional effects on reproduction or wool growth, using sheep immunized against growth hormone-releasing hormone and given a low-quality, sub-maintenance diet. Immunization reduced plasma concentrations of GH at all times measured (P < 0·01), through reduced pulse frequency, reduced pulse amplitude, and reduced baseline concentrations. Plasma insulin-like growth factor-1 (1GF-1) was also reduced in the immunized sheep (P < 0·01). Despite this, rates of live-weight loss and wool growth were similar in immunized and control ewes. Plasma concentrations ofLH and FSH were also similar in immunized and control ewes, both during the late luteal phase and after ovariectomy and supplementation with oestradiol and progesterone. Numbers of ovarian follicles and corpora lutea were also unaffected by immunization. It is concluded that high endogenous concentrations of GH in sheep given food below maintenance are necessary to maintain plasma IGF-1, but do not affect the concentration of gonadotropins or ovarian follicular growth. Furthermore, rates of live-weight loss and the depression in wool growth in such animals were also independent of concentrations ofGH or IGF-1.
Effect of increasing level of spineless cactus (Opuntia ficus indica var. inermis) on intake and digestion by sheep given straw-based diets
Authors: Ben Salem H. , Nefzaoui A. , Abdouli H. , Ørskov E. R. 
Published: September 2010

AbstractThe effects of spineless cactus (Opuntia ficus indica var. inermis) supply on digestion of wheat straw was studied n rumen cannulated sheep. In addition to urea (10 g) and mineral and vitamin mixture (30 g), the animals — received wheat straw alone or supplemented with graded levels of spineless cactus (150, 300, 450 or 600 g dry natter (DM) per head per day). The diets were studied in five successive 25-day periods from February to June 992 in Tunisia. "Water consumption, food intake, digestibility, diurnal variations of ruminal fermentation (pH, mmonia nitrogen, volatile fatty acids, protozoal concentrations in rumen fluid) and cellulolytic activity in the umen were measured.Spineless cactus had high contents of ash (260 g/kg DM) and water (926 g/kg fresh weight) and low neutral-detergent fibre content (185 g NDF per kg DM). Crude protein (CP) content of spineless cactus was 2-5 times reater than that of wheat straw (58 v. 23 g/kg DM, respectively). Drinking water consumption was substantially educed (P < 0·001) as the level of spineless cactus increased. When spineless cactus supply exceeded 300 g DM peray, sheep consumed practically no drinking water. The voluntary intake of straw increased significantly with vineless cactus level. Total diet apparent digesibilities of DM, organic matter and CP tended to increase with mneless cactus supply. Such increase was significant only with the 450 and 600 g levels of cactus. NDF and acidetergent-fibre apparent digestibilities were not affected by spineless cactus supply. Addition of spineless cactus up i 300 g DM significantly increased ruminal ammonia nitrogen (P< 0·001) but there was no additional effect with irther supplementation. When sheep were supplemented with spineless cactus, total rumen volatile fatty acid icreased and acetate: propionate ratio decreased significantly. Moreover, spineless cactus supply increased total wtozoa number and reduced significantly rumen cellulolytic activity measured as DM and NDF disappearance of heat straw from incubated nylon bags.
Resonant frequencies of broiler chickens
Authors: Randall J. M. , Cove M. T. , White R. P. 
Published: September 2010

AbstractMotion is one of the many stressors experienced by broiler chickens during transport. If the resonant frequency of the viscera or whole body corresponds to that of the transporter, the welfare of the birds is likely to be compromised. A vibrating beam technique was used to measure the resonant frequencies of 22 birds which increased in weight from 0·75 to 4·5 kg over 32 days. For a 2-kg bird, the frequencies of 14·6 (s.e. 0·6) Hz when sitting and 3·7 (s.e. 0·8) Hz when standing lie close to the measured resonances of transporters making it likely that bird welfare is compromised due to vibration and motion during transport.
Effect of breed type, sex, method of rearing and winter nutrition on lifetime performance and carcass composition in a 20-month beef system: grazing performance
Authors: Lowman B. G. , Hinks C. E. , Hunter E. A. , Scott N. A. 
Published: September 2010

AbstractIn a lifetime study of spring born cattle managed in a 20-month beef system, four feeding treatments were imposed during the 5-month winter period and two grass heights (low 6 to 8 cm, high 8 to 10 cm) during the subsequent grazing period. Three slaughter weights were imposed over the grazing period, early, mid and late, at an average of 67,110 and 154 days post turn-out. A multi-factorial design was used with three animal factors — maturity (early maturing Hereford crosses v. late maturing Charolais crosses), sex (heifer v. steer) and method of rearing (suckled calves v. bucket-reared calves). There were significant differences in growth rate for both sex and maturity (P < 0·001) and a highly significant negative effect of winter food level on summer growth rate (P < 0·001), the growth rate of food treatment 4 being proportionately 0·61 of that treatment 1.Sward height significantly influenced summer growth rate (P < 0·001) but showed no interaction with winter food level in any of the three grazing periods. Growth rates increased over the summer but differences between winter food treatments decreased with daily gains for food treatment 4 being proportionately 0·44, 0·81 and 0·84 of food treatment 1 as the grazing season progressed.Eliminating winter feeding treatment as a factor and including condition score at turn-out as a co-variate improved the variation explained and reduced differences in growth rate for the main effects with only the main effect of grass height remaining significant. This suggests that the condition of animals at turn-out in conjunction with the subsequent grazing sward height provides a simple practical guide to subsequent animal performance.
Farm animal cognition
Authors: Nicol C. J. 
Published: September 2010

AbstractAlthough there may be task-specific differences in performance between wild and domestic animals, there is no evidence for any generally reduced cognitive capacity in domestic animals. It is not possible to compare intelligence between species or breeds without recognizing the contribution of differences in attention and motivation, and domestic animals often perform better on learning tasks than wild animals because they are less fearful. Considerable flexibility and complexity in behaviour can arise from context-specific decisions that may not require learning. Examples include alarm calling and maternal behaviour in chickens. However, the majority of intelligent behaviour shown by farm animals is dominated by learned associations, sometimes in response to remarkably subtle cues. Seemingly straightforward learning abilities may result in surprising emergent properties. An understanding of these properties may enable us to investigate how farm animals interact socially, and whether they form concepts. Other abilities, such as imitation and the re-organization of spatial information, do not appear to depend on associative learning. The study offarm animal cognition tells us little about the issue of animal consciousness but, none the less, plays an important role in the animal welfare debate. The types of cognitive abilities animals have provide clues as to the types of situations in which (given the benefit of the doubt) they might suffer.
Growth, fertility, prolificacy and fleece weight of Romanov, Finnsheep and Booroola purebreds and their first cross and backcross with the DLS breed
Authors: Fahmy M. H. 
Published: September 2010

AbstractRecords ivere collected on Romanov (R), Finnsheep (F), and Booroola Merino (B); first cross; and backcrosses of these breeds with a new synthetic breed of Dorset, Leicester and Suffolk (DLS). The data covered the period from the birth of ewes to weaning of their progeny. The heaviest lambs at birth were the B backcross and R first and backcrosses (4·1 to 4·0 kg) and the lightest were pure R (3·0 kg). The fastest pre-weaning average daily gain was that ofR crosses. R purebreds were more fertile (109%, P < 0·01) than F (81%) and B (62%). They were also more prolific at birth and at weaning (2·44, 2·13) than F (2·04, 1·71, P < 0·01) and B (2·36, 2·09, P > 0·05) purebreds, respectively. Similarly, first-cross R ewes were more prolific than first-crosses of F and B (1·99 v. 2·86 and 1·70), also backcross R ewes were more prolific than backcrosses ofF and B (1·63 v. 1·45 and 1·42, P > 0·05), respectively. R first-cross ewes had heavier litters (6·31 and 26·1 kg) than B (5·17 and 20·3 kg, P>0·01) and F (5·52 and 24·4 kg) at birth and at day 50. The lambs born to DLS ewes were the heaviest at birth and at day 50 compared with those from prolific ewes. Fleece weight in B and its crosses was significantly higher than in R. Crosses showed generally positive heterotic effect in weights, prolificacy and wool production compared with pure breeds. In two data sets, additive direct effect ofR was higher than that ofF at birth (by 0·11 and 0·10 kg) and at day 50 (by 0·57 and 0 kg) but was similar at day 100 and day 365. The additive direct effect of both R and F was non-significantly different to that of B at birth in both data sets, but in only one data set was it higher (P < 0·001) at day 50 (by 2·29 and 1·72 kg), at day 100 (by 5·24 and 5·30 kg) and at day 365 (by 8·7 and 8·4 kg, respectively). Maternal direct effects ofR was higher (P < 0·05) than F in lamb weights at day 1 and 50, and higher than B in lamb weight at day 50. Individual heterosis between both R and F and DLS were -3·7 and -3·6% in weight at birth, 1·46 and 2·09% in weight at day 50 respectively. The corresponding maternal heterosis were, -2·9, -5·2, 1·46 and -0·02%.
Effects of methylthiouracil treatment on the growth and moult of cashmere fibre in goats
Authors: Rhind S. M. , McMillen S. R. 
Published: September 2010

AbstractThe effect of long-term treatment of goats with methylthiouracil on the timing, amount and quality of secondary fibre (cashmere) growth and timing of cashmere moult in goats was investigated. From early June, groups of 10 Icelandic × Scottish feral goats were dosed orally each day, for a 15-month period, with 5 mg methylthiouracil per kg live weight in 30 ml water (treated; T) or with water only (control; C). Treatment with methylthiouracil resulted in a significant reduction (P < 0·05) in the proportion of active secondary hair follicles present during March. This was associated with a delayed onset of moult of cashmere in T compared with C goats at both the head (11 March v. 23 February; s.e. 3·33 days; P< 0·05) and mid side (27 March v. 26 February; s.e. 3·58 days; P < 0·001). There was no effect on the time of onset (C, 19 July; T, 19 July; s.e. 5·84 days) or cessation of cashmere fibre growth (C, 9 December; T, 8 December; s.e. 1·69 days) or the mean growth rate (C, 0·473 mm/day; T, 0·451 mm/day; s.e. 0·025) and fibre diameter (C, 16·9 μm; T, 15·4 jim; s.e. 0·266). Wlien present in the fleece, the mean weight and proportion of cashmere was higher in C than in T goats (P < 0·05). It is concluded that methylthiouracil treatment altered secondary follicle activity and the time of onset of the moult of cashmere and that these changes may be a result of reduced triiodothyronine production from thyroxine and associated secondary changes in profiles of insulin and IGF-1.
Joint effect of 21 marker loci and effect of realized inbreeding on growth in pigs
Authors: Christensen K. , Fredholm M. , Winterø A. K. , Jørgensen J. N. , Andersen S. 
Published: September 2010

AbstractFour litters produced by father-daughter matings (back crosses) resulting in 35 animals with a theoretical inbreeding coefficient of 25% were typed with 21 independent informative markers. The differences between the two founder animals were estimated, based on the marker information, and it was found that the founder boar had higher genetic potential for proportion of lean meat and lower genetic potential for groivth than the founder sow. The proportion of the genome of each offspring which was identical by descent was investigated. On the basis of these markers the realized inbreeding was found to vary between 7 and 47%. The linear decrease in weight at days 1, 26 and 136, average daily gain and proportion of lean meat regressed on the realized inbreeding were estimated to 0·6 kg, 2·4 kg, 18 kg, 95 g/day and 15 g/kg, respectively. For weight at day 88 a corresponding linear increase of 11 kg was observed. The joint effect of founder differences and realized inbreeding were as expected negative and statistically significant for all growth traits.
Growth and carcass fatness responses of finishing pigs to dietary fat supplementation at a high ambient temperature
Authors: Katsumata M. , Kaji Y. , Saitoh M. 
Published: September 2010

AbstractAn experiment involving 18 individually fed barrows weighing about 81 kg was conducted to determine the effects of a high ambient temperature (30°C v. 22°C) and dietary fat supplementation (100 g/kg diet of encapsulated-tallow v. 0 g/kg) on growth performance and carcass fatness of finishing pigs. Digestible energy (DE) intake and growth rates were significantly lower at a high ambient temperature (P < 0·001). Dietary fat supplementation considerably increased DE intakes at a high ambient temperature (40·0 v. 33·8 MJ/day) while slightly increasing it at a thermoneutral temperature (53·1 v. 50·6 MJ/day). Dietary fat supplementation tended to increase growth rates and significantly improved the efficiency of food utilization (P<0·01). Pigs with dietary fat supplementation exhibited greater enhancement in backfat depths, carcass fatness and internal organ fat at a high ambient temperature than at a thermoneutral temperature. Linear correlation between DE intake and crude fat concentration of carcasses was statistically significant at a high ambient temperature (P < 0·01, r = 0·71). Although there appeared to be a positive correlation, it was not statistically significant at a thermoneutral temperature (P > 0·05). Crude fat concentration of the internal organs linearly correlated with DE intake (P < 0·01, r = 0·66). However, fat concentration of the internal organs did not correlate to DE intake at a thermoneutral temperature. The present study indicated that although dietary fat supplementation improved growth performance of pigs over 81 kg live weight initially in hot environments, there was the disadvantage of excessive fat deposition in their bodies.
Seasonal patterns of growth, voluntary food intake and plasma concentrations of prolactin, insulin-like growth factor-1, LH and gonadal steroids in male and female pre-pubertal red deer (Cervus elaphus) reared in either natural photoperiod or constant daylength
Authors: Adam C. L. , Kyle C. E. , Young P. 
Published: September 2010

AbstractRed deer calves were reared from birth to 16 months in either constant intermediate 12L: 12D daylength (ID) or in natural photoperiod (NP) (four males and four females per group) to investigate effects on the somatotropic and reproductive axes, and to compare responses between the seres. Measurements, starting from 3 months (September), were made each week of live weight (LW), voluntary food intake (VFI), plasma prolactin, plasma insulin-like growth factor-1 (IGF-1), and plasma progesterone (females), and every 2 months of pulsatile LH secretion, plasma testosterone (males), responses to exogenous GnRH, and antler development (males).Both sexes in ID compared with NP had significantly higher LW gain (males, P < 0·001; females, P < 0·01) and VFI (P < 0·001) between winter solstice (WS) and spring equinox (SE), and VFI between SE and summer solstice (SS) (males, P < 0·05; females P < 0·01). Both sexes had significantly lower plasma prolactin concentrations in ID than in NP (males, P < 0·05; females, P < 0·01) between SE and SS. However, plasma IGF-1 was only significantly altered in males, being significantly higher in ID than NP between WS and SE (P<0·01). ID and NP females showed no significant differences in pulsatile LH secretion nor in the timing of pubertal ovulation. However, ID compared with NP males at 10 months (just after SE) had higher LH and testosterone pulse frequencies (P < 0·01), and at 12 months (just before SS) had higher mean testosterone concentrations (P < 0·01) and testosterone response to GnRH challenge (P<0·001). ID antlers hardened earlier at 11 months than NP antlers at 14 months (P < 0·001).Thus ID compared with NP in both sexes prevented the winter reduction in growth and appetite and the summer elevation in prolactin secretion, and in males, but not in females, stimulated higher IGF-1 secretion in winter, an earlier increase in LH pulse frequency, and an earlier increase in gonadal steroid production. This study has therefore revealed some intriguing similarities and contrasts in the responses to photoperiod shown by young male and female deer.
Genetic parameters for faecal egg count following mixed, natural, predominantly Ostertagia circumcincta infection and relationships with live weight in young lambs
Authors: Bishop S. C. , Bairden K. , McKellar Q. A. , Park M. , Stear M. J. 
Published: September 2010

AbstractFaecal egg counts and live weights were measured on approximately 200 predominantly twin-born Scottish Blackface lambs each year for 3 years, from 1 to 6 months of age. Measurements were made at 4-week intervals following anthelmintic treatment. Heritability estimates (with s.e.s) of log transformed faecal egg count at each age were 0·01, 0·00, 0·12 (0·10), 0·14 (0·12), 0·15 (0·07) and 0·22 (0·13), for ages 1 to 6 months respectively. Therefore, genetic variation exists for acquired but apparently not for innate resistance to infection. Maternal common environmental effects (with s.e.s) were 0·36 (0·11), 0·20 (0·05), 0·27 (0·09), 0·06 (0·08), 0·15 (0·09) and 0·16 (0·08), for ages 1 to 6 months respectively. Genetic correlations between faecal egg counts in lambs older than 3 months were not significantly less than 1·0, indicating that faecal egg counts at different ages are expressions of the same trait. Phenotypic correlations between faecal egg counts were generally positive but small. Measurement error contributed one-third of the observed variation for individual egg counts. The heritability of mean faecal egg count from 3 to 6 months was 0·33 (s.e. 0·15), indicating that selection decisions can be made more accurately using multiple egg counts per animal. Phenotypic correlations between faecal egg counts and live weight were generally negative but close to zero. However, genetic correlations between faecal egg counts and live weight in lambs older than 3 months were close to -1·0, indicating that resistance to gastrointestinal parasites may be an important genetic determinant of growth rate in this environment.