Five musk deer species (genus Moschus) are distributed in China, and the present estimated numbers in the wild are between 220 000 and 320 000. Population size of musk deer has dropped significantly due to historical over-hunting and loss or degradation of their habitat. Musk deer farming, therefore, has become one of the most appropriate ways to protect and utilize musk deer resources. In China, musk deer farming and extracting musk from the captive musk deer have been reasonably successful since the early 1950s. At present three species of musk deer, namely forest (Moschus Berezovskii), alpine (M. sifanicus) and Siberian (M. moschiferus) musk deer are farmed in China and, of these, the forest musk deer is the main captive population. The present patterns of musk deer farming in China, however, need to be improved and developed into more economic and scientific modes in order to improve the rate of survival and reproduction, and to increase the production of musk.

The objective of this study was to examine genetic changes in reproduction traits in sows (total number born (TNB), number born alive (NBA), average piglet birth weight (ABW) and number of piglets weaned (NW), body weight prior to mating (MW), gestation length (GL) and daily food intake during lactation (DFI)) in lines of Large White pigs divergently selected over 4 years for high and low post-weaning growth rate on a restricted ration. Heritabilities and repeatabilities of the reproduction traits were also determined. The analyses were carried out on 913 litter records using average information-restricted maximum likelihood method applied to single trait animal models. Estimates of heritability for most traits were small, except for ABW (0·33) and MW (0·35). Estimates of repeatability were slightly higher than those of heritability for TNB, NBA and NW, but they were almost identical for ABW, MW, GL and DFI. After 4 years of selection, the high growth line sows had significantly heavier body weight prior to mating and produced significantly more piglets born alive with heavier average birth weight than the low line sows. There were, however, no statistical differences between the selected lines in TNB or NW. The lower food intake of high relative to low line sows during lactation was not significant, indicating that daily food intake differences found between grower pigs in the high and low lines (2·71 v. 2·76 kg/day, s.e.d. 0·024) on ad libitum feeding were not fully expressed in lactating sows. It is concluded that selection for growth rate on the restricted ration resulted in beneficial effects on important measures of reproductive performance of thea sows.

Genetic parameters were estimated using uni- and bi-variate random regression models for weight, eye-muscle depth and fat depth measures between 60 and 360 days of age. Each trait was measured up to five times in 50-day intervals following weaning on approximately 4000 Australian Poll Dorset Sheep. The model accounted for rearing type, dam age, management group and age of recording. The model used for analysing weight included quadratic, orthogonal polynomials for direct genetic and environmental effects, a linear polynomial for maternal genetic effects and heterogeneous error variance across ages. The fat and muscle analysis used linear orthogonal polynomials for direct genetic and environmental effects and heterogeneous error variance. Throughout the 300-day trajectory heritability for weight traits ranged from 0·20 to 0·31, while heritability for fat depth ranged from 0·24 to 0·34 and heritability for eye-muscle depth ranged from 0·24 to 0·40. Genetic correlations between repeated measures of the same trait at different ages were positive and declined as the age interval increased, to minimum values of 0·60, 0·31 and 0·50 for weight, fat and muscle respectively between 60 and 360 days of age. Genetic correlations between weight and fat and weight and eye muscle were moderate to high (0·6 to 0·8) and positive but decreased slightly with age. The genetic correlations between fat and muscle were moderate to high (0·5 to 0·7) throughout the 300-day trajectory. In all cases, the estimates produced in this study were reasonably consistent with the limited number of studies that exist in the reported literature. This study demonstrated the relationships that exist between repeated measures of weight, fat and muscle measures over time, which is of interest to prime lamb producers looking to select for specific breeding objectives or market end points requiring precise weight, fat and muscle combinations at certain ages.

These studies were conducted to determine whether dietary homoarginine, derived from guanidination of synthetic lysine, affects the measurement of apparent and true ileal amino acid digestibility in the pig and to determine the optimal ratio of o-methylisourea (OMIU) to free synthetic lysine in the guanidination reaction that produces homoarginine. In two preliminary experiments, specific amounts of lysine were weighed and added to a solution of 0·6 mol/l OMIU to produce OMIU to free synthetic lysine ratios of 2:1, 1·5:1, 1·4:1, 1·3:1, 1·2:1, 1·1:1 and 1·0:1. The mixture was incubated at a pH of 10·5 and a temperature of 20±1°C for 6 days. The highest yield of homoarginine (proportionately 0·995) was produced with an OMIU to free synthetic lysine ratio of 1·5:1. The serum concentrations of homoarginine and lysine were measured in two test pigs at various times after consuming a single meal containing either homoarginine or lysine. Blood samples were taken before and 0·5, 1·5, 2·5, 4·5, 6·0, 7·5, and 11·5 h after feeding. Thirty minutes after feeding the homoarginine-containing diet, the homoarginine concentration in serum was 0·013 mmol/dl, and increased to a maximum of 0·031 mmol/dl 1·5 h after feeding. Thirty minutes after feeding the lysine-containing diet, the serum lysine concentration was 0·011 mmol/dl and also reached its maximum concentration of 0·025 mmol/dl 1·5 h after feeding. The timing of the changes in concentration of homoarginine and lysine related to feeding were similar, which suggests that homoarginine is absorbed and metabolized in a similar manner to lysine. Six Large White×Landrace barrows, weighing 68·5±3·5 kg and fitted with a simple T-cannula at the distal ileum as well as a jugular vein catheter, were used to determine the effects of homoarginine on endogenous amino acid flows and apparent and true ileal amino acid digestibility. The experimental design was a doubly replicated 3×3 Latin-square design with the three treatments consisting of a lysine-free, zein-based diet and jugular infusion of a lysine solution; a lysine-free, zein-based diet supplemented with homoarginine; and a lysine-free, zein-based diet supplemented with l-lysine. There were no significant differences in endogenous ileal lysine flow for pigs receiving the different treatments (396·6, 407·6, and 360·4 mg/kg DMI, respectively, P=0·71). In addition, with the exception of phenylalanine (P=0·04), there were no significant differences (P>0·10) in the apparent and true ileal digestibility of crude protein and amino acids among the three treatments. Therefore, it would appear that the presence of dietary homoarginine, derived from guanidination of synthetic lysine, does not affect endogenous amino acid losses or the digestibility of crude protein as well as most amino acids. These results are therefore supportive of the use of the homoarginine method as a means of measuring true ileal lysine digestibility.

The objective of this study was to determine the proportion of forage in the diet which would maximize duodenal flow of unsaturated fatty acids in beef steers supplemented with linseed oil. A second objective was to determine how diets differing in forage content, but equal in nitrogen (N), energy and lipid supply, would affect the duodenal flow of C18:1 and conjugated linoleic acid (CLA) isomers. Eight Hereford×Friesian steers (533±13·6 kg), prepared with rumen and duodenal cannulae were offered one of four forage:concentrate (F:C) ratios: F80C20; F60C40; F40C60 and F20C80 on a dry-matter (DM) basis. All diets were offered at 0·013 body weight and designed to be isonitrogenous and isoenergetic with total lipid made up to 0·06 DM intake with linseed oil. The experimental design was a replicated incomplete 4×4 Latin square with three periods. Increasing the concentrate component in the diet from 0·20 to 0·60 reduced rumen pH from 6·58 to 6·37 and caused a small but significant shift in volatile fatty acid molar proportions, decreasing the non-glucogenic ratio. Rumen ammonia-nitrogen concentration was also significantly reduced with increasing concentrate, from 156·8 to 101·0 mg N per l on F80C20 and F20C80, respectively. Microbial nitrogen (MN) and the efficiency of microbial protein synthesis was significantly elevated as forage level decreased from 51·6 to 72·4 g/day and 17·2 to 27·3 g MN per kg organic matter apparently digested in the rumen, respectively for F80C20 and F20C80. Intake and duodenal flow of C18:1n-9 and C18:2n-6 were significantly higher with increasing concentrate level in the diet whereas C18:3n-3 intake and flow was not different, averaging 143·6 and 6·37 g/day, respectively. There were no differences in the flows of total C18:1 trans or CLA (47·7 and 1·79 g/day, respectively) across the diets. However, although not significantly different in duodenal flow there were trends (P<0·1) for an increasing proportion of trans-10 and a decreasing proportion of trans-11 when increasing the concentrate in the diet. Biohydrogenation of C18:2n-6 decreased from 0·91 to 0·85 when increasing concentrate in the diet from 0·20 to 0·40 but further increases had no effect. F:C ratio had little effect on the flow of unsaturated fatty acids, C18:1 trans and CLA to the duodenum of beef steers, and this may relate to the ability of the rumen to buffer the large changes in concentrate intake.

Advancing maturity of forage maize is associated with increases in the proportion of dry matter (DM) and starch and decreases in the proportions of structural carbohydrates in the ensiled crop. Three maize silages (286 (low, L), 329 (medium, M) and 379 (high, H) g DM per kg fresh weight) plus a concentrate formulated to give isonitrogenous intakes were offered to Holstein-Friesian steers fitted with a cannula in the dorsal sac of the rumen and a ‘T’ piece cannula in the proximal duodenum in an experiment with a cross-over design that allowed four collection periods. Nutrient flow to the duodenum was estimated using chromium-EDTA. Steers consumed approximately 0·6 kg DM per day less of diet L compared with the other two diets (P=0·026), resulting in less DM being digested (P=0·005) but digestibility did not differ between diets. Similar results were obtained for organic matter. There were no differences between diets in the intake or digestibility of neutral-detergent fibre. Intake, duodenal flow and faecal output of starch were greater for steers offered diets M and H compared with those given diet L (P<0·05). In all diets rumen digestion contributed to over 90% of total digestion of starch, although rumen digestibility declined significantly with advancing maize maturity (P=0·002). Molar proportions of acetic acid were higher in diet H (P<0·05) whilst proportions of propionic acid and n-butyric acid were higher in diets M and L. There were no significant differences between diets in mean rumen pH or ammonia concentrations. Mean circulating concentrations of insulin were higher (P=0·009) in cattle given diets L and M compared with diet H. There were no differences between diets in the mean circulating concentration of growth hormone, or the frequency, amplitude and duration of growth hormone pulses, or the mean circulating concentrations of IGF-1. Changes in forage composition that accompany advancing maize maturity affect overall silage digestion and circulating concentrations of insulin.

Digestion and absorption of carotenoids were studied in sheep given, twice daily, fresh red clover. Digestive fluxes were measured in six sheep cannulated in the rumen, duodenum and ileum using the double marker technique. Another five sheep were fitted with catheters allowing nutrient net flux measurements across the portal-drained viscera. Carotenoids in the red clover consisted of lutein (136 μg/g dry matter (DM)), epilutein (40 μg/g DM), trans-β-carotene (16 μg/g DM) and 13-cis-β-carotene (13 μg/g DM). Intake was 174, 52, 21 and 17 mg/day, and faecal excretion was 181, 25, 50 and 41 mg/day, for lutein, epilutein, trans- and 13-cis-β-carotene respectively, indicating net production of β-carotene in the digestive tract. The difference between duodenum and intake was positive for all carotenoids (30, 4, 43 and 37 g for lutein, epilutein, trans-β-carotene and 13-cis-β-carotene, respectively) suggesting net production and/or release of carotenes and xanthophylls by rumen microbes. Apparent digestibility in the small and large intestines was 0·18 and −0·05 for lutein, 0·30 and 0·29 for epilutein, 0·39 and 0·26 for trans-β-carotene, 0·53 and 0·21 for 13-cis-β-carotene. Only lutein and epilutein were recovered in arterial plasma, at a concentration of 14·3 and 10·8 μg/l, respectively. Their portal net appearance was not different from 0, suggesting that absorption occurred mainly via the lymphatic system.

An experiment was conducted to investigate the influence of the main cereal (cooked maize or cooked rice) and the inclusion of cooked and expanded oat hulls (0, 20 or 40 g/kg) in the diet on total tract apparent nutrient digestibility (TTAD) and productive performance of piglets weaned at 21 days. Each of the six treatments was replicated eight times (five piglets penned together) and the trial lasted for 33 days. From 21 to 41 days of age piglets were given their respective experimental complex diets that contained 530 g/kg cooked cereal and from 41 to 54 days they received a common starter diet based on maize, barley and soya-bean meal. Growth promoters were not included in the diets. The TTAD was determined at 27 and 37 days of age and pig performance was measured at 31, 41 and 54 days of age. Nutrient digestibility increased with age ( P<0·001) and in general were higher for rice- than for maize-based diets ( P<0·001 for dry matter, organic matter and gross energy and P<0·05 for ether extract). From 21 to 41 days of age piglets given rice had higher food intake (FI, P<0·05) and average daily gain (ADG, P<0·01) than piglets given maize but food conversion ratio was not affected. The differences observed were maintained until the end of the trial. The inclusion of oat hulls in the diet did not affect TTAD of the nutrients but tended to reduce the incidence of diarrhoea from 21 to 41 days of age ( P<0·1). Oat hulls inclusion reduced FI and ADG in diets based on maize but had the opposite effect in diets based on rice, indicating that piglets might have a minimum requirement for dietary fibre. It is concluded that cooked rice is an ingredient of choice in pre-starter diets for weanling pigs. Also, the inclusion of moderate levels of fibre as oat hulls reduces the incidence of diarrhoea and might improve productive performance in low fibre diets.

Three trials were conducted to determine the optimum dietary lysine concentration for maximum growth rate (ADG) or minimum food conversion ratio (FCR) of boars and gilts from 60 to 90 kg (in pairs) and 80 to 100 kg (in pairs or groups). Ninety pairs of pigs and six treatments (dietary lysine concentrations) were used in experiment 1 (60 to 90 kg), 144 pairs and eight treatments in experiment 2 (80 to 100 kg) and groups of 13 pigs (no.=42 groups) and six treatments in experiment 3 (80 to 100 kg). Experiments were arranged as randomized-block designs, blocked on the basis of sex and start weight. Isoenergetic diets (13·8 MJ digestible energy per kg) were based on barley, wheat, soya-bean meal, with added vitamins, minerals and amino acids. Dietary lysine concentrations were: 7·9, 8·8, 9·7, 10·7, 11·7 and 12·5 g/kg in experiment 1; 7·0, 7·9, 8·8, 9·7, 10·7, 11·7, 12·5 and 13·5 g/kg in experiment 2; and 7·0, 7·9, 8·8, 9·7, 10·7 and 11·7 g/kg in experiment 3. In experiment 1 (60 to 90 kg pairs), ADG increased (quadratic, P<0·01) and FCR improved (quadratic, P<0·001) with increased lysine concentration. Although boars grew faster (P<0·001) and were more efficient (P<0·001) than gilts, maximum ADG was predicted at 10·8 g lysine per kg and minimum FCR at 10·9 g lysine per kg for all pigs. In experiment 2 (80 to 100 kg pairs), a treatment×sex interaction for ADG (P<0·01) and FCR (P<0·05) indicated that boars grew faster and had better FCR than gilts at dietary lysine concentrations above 10·7 and 9·7 g/kg respectively, with no difference between the sexes below these lysine levels. Maximum ADG was predicted at 11·8 and 9·9 g lysine per kg and minimum FCR was predicted at 11·9 and 10·0 g lysine per kg for boars and gilts, respectively. In experiment 3 (80 to 100 kg groups) ADG increased (quadratic, P<0·01) and FCR improved (quadratic, P<0·001) as dietary lysine concentration increased. Boars had higher ADG (P<0·001) and better FCR (P<0·001) than gilts. Maximum ADG and minimum FCR were predicted at 9·3 and 9·6 g lysine per kg for all pigs. In conclusion, boars grew faster and more efficiently than gilts, with interactions in experiment 2 indicating a greater difference in performance at higher dietary lysine concentrations.

The effective ruminal degradability (ED) of dry matter (DM), crude protein (CP) and amino acids, and the effective intestinal digestibility (IED) of DM and CP of a sample of whole cottonseed was measured using in situ and rumen outflow rate techniques in three wethers cannulated in the rumen and duodenum. The microbial contamination of rumen incubated residues was corrected by a continuous rumen infusion of 15NH3 as microbial marker and rumen solid associated bacteria as reference sample. Microbial contamination resulted in an overestimation of the undegradable fraction of DM (0·291 v. 0·275; P<0·05) and CP (0·071 v. 0·037; P<0·01) and a small underestimation of ED of DM (0·500 v. 0·512; P=0·09) and CP (0·755 v. 0·779; P=0·052). A proportion of 0·1 of the ruminal undegraded CP was of microbial origin and for essential amino acids this proportion varied from 0·042 to 0·150. Differences in ED between amino acids modified the amino acid profile, with an important reduction (0·2; P<0·01) in the proportion of lysine. Apparent intestinal digestibility of the insoluble fraction of this food, measured with the mobile nylon bag technique, showed large reductions (P<0·001) with the increase of the ruminal incubation time between 0 and 72 h: from 0·392 to 0·026 for DM and from 0·851 to 0·099 for CP. These evolutions fitted an exponential function with a previous lag. The IED was estimated either by integration of these equations and those describing the ruminal degradation and rumen outflow or by incubation through the intestines of a sample pooled to be representative of rumen flow of the undegraded food. The two methods gave similar values for both DM (0·222 v. 0·203) and CP (0·659 v. 0·658).

The purpose of this work was to quantify the additive genetic correlations between prevalent radiographic findings in the limbs of Warmblood riding horses and performance parameters. Data on 3725 Hanoverian Warmblood horses selected for sale at auctions in the period 1991 to 1998 were used. The numbers of annual entries (TE) and placings (TP) in tournament competitions in the period 1991 to 2002 served as measures of performance in riding sports. Multivariate genetic analyses were performed in linear animal models using restricted maximum likelihood (REML). The four most prevalent radiographic findings, i.e. osseous fragments in fetlock (OFF) and hock joints (OFH), deforming arthropathy in hock joints (DAH) and pathologic changes in navicular bones (PCN) were analysed jointly with the performance parameters, i.e. TE and TP. Additive genetic correlations between the radiographic findings and the performance in sports were in many cases close to zero. There were some indications for significantly negative, but few indications for significantly positive additive genetic correlations between radiological conditions in the equine limbs and the performance of Warmblood riding horses in dressage, show-jumping and basic build-up competitions. Breeding measures that allow for orthopaedic health traits could therefore contribute to maximize the breeding progress in terms of sport performance.

The objective of this study was to determine the effect of stage of lactation on the concentration of polyamines (spermine, spermidine, and putrescine) in sow colostrum and milk. Ten, third parity sows (Landrace×Yorkshire) were sampled throughout a 28-day lactation. Litter size for all sows was standardized at 10 sucking piglets immediately after farrowing. Colostrum collection began at the birth of the first piglet (0 h), and colostrum was subsequently collected 6, 12, 18, and 24 h after farrowing. Sow milk was sampled on days 3, 7, 10, 14, 17, 21, 24 and 28 of lactation. Spermine concentration in sow colostrum was relatively constant for the first 12 h after farrowing and then rapidly increased to 10·26 μmol/l 24 h after farrowing (linear and quadratic effect; P<0·01). In contrast, the concentrations of spermidine and putrescine showed little change during the first 24 h with spermidine concentration in colostrum ranging from 3·76 to 4·54 μmol/l, and putrescine concentration ranging from 1·15 to 1·52 μmol/l. The highest concentration of spermine in sow milk was 18·82 μmol/l, observed on day 7, with levels gradually declining to 4·28 μmol/l by day 28 of lactation (linear and quadratic effect; P<0·01). In contrast, the concentration of spermidine increased during lactation ranging from a low of 4·32 μmol/l on day 7 to a high of 9·01 μmol/l on day 28 of lactation (linear effect P<0·01; quadratic effect P=0·03). Putrescine concentration ranged from 1·53 μmol/l on day 3 to 1·84 μmol/l on day 28 (linear effect P=0·07; quadratic effect P>0·05). The results of this study show sow colostrum and milk provide polyamines for sucking piglets before weaning, which could potentially modulate intestinal maturation.

The objectives were to demonstrate the potential of heat production measurements to characterize the gross and net efficiencies of dairy cows under commercial conditions and to compare the efficiencies of purebred Holstein and Montbeliarde × Holstein F1 dairy cows. The heat productions of seven Holstein (H) and seven Montbeliarde × Holstein (MH) cows were measured over two 10-day periods separated by a 75-day interval, during the summer of 2004, in a commercial high-yielding dairy herd in Israel. Energy expenditure was measured by monitoring heart rates and oxygen consumption per heart beat. Milk yield and composition were recorded for these cows and their investment of energy in the milk was calculated from the milk yield and composition. Live weight and body condition score were also recorded in parallel with these measurements. Metabolizable energy (ME) intake was estimated as the sum of heat production, energy in milk and body energy balance. The MH cows were heavier by 90 kg, had higher body condition scores by 0·9 units and secreted proportionately 0·19 and 0·38 less energy in their milk than H cows in the first and second periods, respectively. The gross energy efficiencies, expressed as the percentage of milk production plus body retention in ME intake were 48·3 and 43·4% in the first period and 45·6 and 32·8% in the second period, for H and MH cows, respectively. The milk production of MH cows in this study was lower than the potential of this cross, however, MH cows that expressed this potential would still be expected to require proportionately 0·10 greater intake of ME than H cows, per unit of energy in milk.

Partial least-squares (PLS) models based on visible (Vis) and near infrared reflectance (NIR) spectroscopy data were explored to predict intramuscular fat (IMF), moisture and Warner Bratzler shear force (WBSF) in pork muscles (m. longissimus thoracis) using two sample presentations, namely intact and homogenized. Samples were scanned using a NIR monochromator instrument (NIRSystems 6500, 400 to 2500 nm). Due to the limited number of samples available, calibration models were developed and evaluated using full cross validation. The PLS calibration models developed using homogenized samples and raw spectra yielded a coefficient of determination in calibration (R2) and standard error of cross validation (SECV) for IMF (R2=0·87; SECV=1·8 g/kg), for moisture (R2=0·90; SECV=1·1 g/kg) and for WBSF (R2=0·38; SECV=9·0 N/cm). Intact muscle presentation gave poorer PLS calibration models for IMF and moisture (R2<0·70), however moderate good correlation was found for WBSF (R2=0·64; SECV=8·5 N/cm). Although few samples were used, the results showed the potential of Vis-NIR to predict moisture and IMF using homogenized pork muscles and WBSF in intact samples.

A bull beef finishing experiment was conducted with the objective of comparing physical performance of constrasting genotypes of suckler-bred bull beef animals finished intensively on a cereal-based diet at approximately 12 to 13 months of age. Nine bulls per genotype were drawn from weaned, bull calves born to one of two dam types (Belgian Blue×Holstein/Friesian (BB) or Simmental×Holstein/Friesian (SIM)) and which had been sired by one of two contrasting sire types (Aberdeen Angus (AA) or Charolais (CH)). Bull calves were weaned at approximately 8 months of age and the finishing experiment ran from approximately 9 months of age until slaughter at 12 to 13 months of age. Cereal-based concentrate diets were offered to all bulls on an ad libitum basis throughout the experimental finishing period. Dry matter intake (DMI), live-weight gain (LWG), food conversion ratio (FCR), and carcass slaughter characteristics were quantified.

Average daily LWG was 2·07, 2·11, 2·34 and 2·65 kg/day, average FCR was 5·14, 5·06, 4·70 and 4·12 kg DMI per kg LWG and average age at slaughter was 387, 381, 374 and 366 days for the AA/BB, AA/SIM, CH/BB and CH/SIM bulls respectively. These figures showed that CH sired bulls grew faster ( P<0·001), finished at an earlier age ( P<0·01) and had better food conversion ratios ( P<0·01) than AA sired bulls. CH sired bulls also produced heavier carcasses (P<0·001) with better conformation ( P<0·001) than AA sired bulls. Average cold carcass weights (CCW) at slaughter were 309, 318, 348 and 365 kg and average conformation scores (15-point scale) at slaughter were 9·28, 10·28, 12·39 and 12·75 for the AA/BB, AA/SIM, CH/BB and CH/SIM bulls respectively. Finished bulls from SIM dams had higher LWGs (P<0·01) and produced heavier carcasses (P<0·05) than bulls from BB dams. No statistically significant differences in fat score (15-point scale) were seen between any of the breed combinations with fat scores of 7·50, 7·25, 6·75 and 6·75 for the AA/BB, AA/SIM, CH/BB and CH/SIM bulls respectively. No significant differences in average daily food intake were observed between breed combinations in the experiment with average daily DMI being 10·6, 10·6, 11·0 and 10·9 kg/day for AA/BB, AA/SIM, CH/BB and CH/SIM bulls respectively.

Overall, there was little evidence to suggest that the rate of bull LWG declined to bring about any meaningful reduction in productivity as average bull live weight increased from approximately 9 months of age until slaughter at 12 to 13 months of age. When finished on a nutrient-rich, cereal-based concentrate diet, excellent animal performance and commercially acceptable carcasses can be produced from the UK suckler herd using genetically superior sires of either traditional UK or continental beef cattle breeds. Results from this study indicate that CH sired bulls out-performed AA sired bulls, especially when produced from SIM cows.

Thirty-six young fattening bulls from three breeds (Belgian Blue, Limousin and Aberdeen Angus) were fattened over 5 months with fattening diets based either on sugar-beet pulp or on cereals. Fattening performance as well as carcass and meat characteristics were measured. There were few relevant effects of the diets on the parameters. The breeds also showed similar fattening features. However, the BB had higher killing-out proportion and their carcasses presented better scores in terms of conformation and fattening. The meat quality of the breeds differed, especially in terms of luminosity, redness and cooking losses. There were also significant influences of breed on the chemical composition of meat; fat content was lowest in Belgian Blue and highest in Aberdeen Angus. Such specificities could help to allocate breeds in appropriate niches in Belgium.