Repeated measures of live weight in growing animals are used to describe the path by which they travel from birth to maturity. A family of growth functions-the Gompertz is one in particular-has been used successfully to describe this journey with relatively few parameters (most importantly mature size and a rate parameter). However, using these functions to differentiate the genetic merit of individual animals to grow is problematic since the estimates of these parameters are highly correlated and are obtained with varying precision among animals. An alternative is random regression (RR) methodology. It allows environmental effects specific to the time of recording to be accounted for and can accommodate genetic differences in the shape of each animal’s growth curve. At present, though, only linear models (polynomials) can pragmatically be fitted with RR. This may be limiting since a priori beliefs about the appropriate form of a growth function, such as the non-linear Gompertz equation, cannot be accommodated. This paper describes the application of RR techniques to describe growth on a population of Suffolk sheep and compares the genetic evaluation predicted from a RR model with that obtained from a more traditional method based on a Gompertz form.

The RR model chosen as providing the best fit (P < 0·01) included additive genetic and permanent environmental (between repeat records of an individual) effects fitted to a fifth order polynomial, and dam effects fitted to a third order polynomial. Measurement error was modelled as six classes. The heritability varied at different points along the growth trajectory (from 0·09 at 15 days to 0·33 at 150 days), suggesting that live weight early in a lamb’s life is a different trait to live weight later in life. There was genetic variation in the growth curves of individual animals, which was accounted for by fitting a RR model. Breeding values obtained by RR and a Gompertz approach were moderately to highly correlated (0·81 at 56 days, 0·91 at 150 days). If breeding value for live weight at 150 days of age were the selection criterion, similar individuals would be chosen with both methodologies. The ‘better’ properties and greater flexibility of the RR approach are discussed.

In experiment 1, female Wistar rats (no. = 24) with free access to food were treated daily for 8 days with subcutaneous injections of saline or 0·5 mg/kg of the α2-adrenoceptor agonist, guanfacine hydrochloride. In experiment 2, female Wistar rats (no. = 24), restricted to 12 g food per day were treated daily for 45 days with subcutaneous injections of 1 μl/g body weight saline containing 0, 0.001, 0.025 or 0·5 mg/kg guanfacine hydrochloride. In experiment 1, the control and treated groups consumed similar amounts of food but the guanfacine-treated animals gained less body weight (P 0.05) and less muscle mass (P 0.01). The treated animals had pronounced glucosuria (P < 0.05) during the whole treatment period. At slaughter, the treated group had higher blood glucose (P < 0.001) and serum corticosterone (P < 005) but insulin concentrations were not different. In experiment 2, only the 0.5 mg/kg dose of guanfacine had significant effects. Resting oxygen consumption on day 29 of treatment was proportionately 0.10 lower in this group compared with controls (P < 0.05). There was no effect of treatment on growth rate. After 46 days, the 0·5 mg/kg treatment group had proportionately 0·35 more body fat (P < 0.01), higher body fat content (P < 0.01), higher total body energy (P < 0.05) and higher total body energy content (P < 0.05). Experiment 1 linked reduced growth rate with increased corticosterone concentrations and experiment 2 suggested the mechanism may be a repartitioning of energy storage to lipid. However, it was not determined whether these consequences were a direct effect of guanfacine or a secondary effect due to corticosterone. In spite of reductions in energy expenditure, guanfacine retards growth in rats and mice, but not in cattle where growth is enhanced. Thus rodents may have a limited usefulness as models for studies of α2-adrenoceptor agonists in cattle.

The present study was conducted to determine the effect of growth rate of calves on the activity of the calpain system post mortem, post mortem desmin degradation, myofibrillar fragmentation index and meat tenderness of m. longissimus lumborum (LL) and m. supraspinatus (SS). Twenty-four Friesian heifer calves were allocated to two treatment groups: MM and HH. The MM calves were given food to achieve a moderate growth rate (678 g/day from 5 days of age to 90 kg body weight (BW) (period I) and 770 g/day from 90 kg BW to slaughter at 250 kg BW (period II)) and the HH calves were given food to achieve a high growth rate (period I: 895 g/day and period II: 1204 g/day). The myofibril fragmentation index (MFI), desmin degradation and the activity of µ-calpain, m-calpain and calpastatin were measured in LL and SS at slaughter, and 1 and 7 days post mortem. Shear force was measured in LL and SS after 1 and 7 days of ageing and a sensory panel evaluated the eating quality of the loin aged 7 days. MFI (P < 0·01) and tenderness (P < 0·01) were higher and shear force was lower (P < 0·001) in meat from HH calves compared with meat from MM calves. However, growth rate did not affect the activity of µ-calpain, m-calpain or calpastatin or the degradation pattern of desmin at any time post mortem. Besides growth rate and MFI at day 7 post mortem, which both correlated positively with meat tenderness (P < 0·001 and P < 0·01, respectively), fibre type traits and DNA or RNA concentrations were not generally related to final tenderness. Thus, it was concluded that increased growth rate of calves before slaughter increased the ease of fragmentation (MFI) of the meat and improved the tenderness but these findings could not be related to any changes in the activity of the calpain system.

Although ostriches are herbivores, their diets in commercial farming in Israel consist mainly of concentrates. The objective of this study was to evaluate an alternative for fattening ostriches aged 10 to 30 weeks, which combines pasture with concentrate feeding. Chicks were allotted to three treatments. Diet of group C40 consisted of concentrate only, provided at 40 g/kg body mass (mb). Groups CG20 and CG30 received concentrate at 20 and 30 g/ kg mb, respectively, and grazed 4 to 6 h/day on lush green alfalfa (Medicago sativa), sown barley (Hordeum vulgare), natural pasture or sulla (Hedysarum coronarium). During the last 10 weeks of experiment, groups CG20 and CG30 were merged into one group, managed as CG20 and grazed natural pasture, sulla, alfalfa, or vetch (Vicia sativa). Ostriches from group CG20 and CG30 consumed 390 (s.e.30) g and 260 (s.e. 20) g DM per day at pasture, i.e. 0·46 and 0·28 of their total daily intake, respectively. Pasture intake for CG20 was higher (P < 0·05) than for CG30. Intake of pasture (both grazing treatments combined) was twice as much as on natural pasture or alfalfa as on barley. These results were consistent with the ostriches’ preference for forbs rather than grasses in the natural pasture. The mean organic matter digestibility was 0·84 (s.e. 0·01), ostriches gained at 347 (s.e. 13) g/day, and the food conversion ratio was 3·05 (s.e. 0·16), with no effect of group. Also, grazing did not affect the dressing rate (0·47, s.e. 0·015) or the size and mass of the different parts of the gastro-intestinal tract, with the exception of the glandular and muscular stomachs, which were proportionately 0·4 (P < 0·05) heavier in grazing birds. Lower (P < 0·05) fat content (33·8 v. 26·5 g/kg) but not tenderness, of a selected muscle (fibularis longus) was found for grazing birds. This study suggests that, in young ostriches, grazing lush green pasture may reduce concentrate intake by proportionately 0·4, without altering growth performance or carcass yield and quality.

Neonatal piglets were given three daily injections of dexamethasone at 1 mg/kg body weight to examine if their stress response and carcass fat distribution at a 120-kg market weight could be altered. The daily acute injections tended to increase the amount of muscle and adrenal leptin mRNA expression (P < 0·1) for 1 and 3 days after the end of the treatment but had no effect on the amount of glucocorticoid receptor mRNA. The treated animals had a 19% lower adult stress response to transport than the controls as measured by salivary cortisol levels. There was no significant change in the treated animals’ carcass and meat quality traits at market weight. However, a trend towards more marbling fat and carcass backfat were seen in the dexamethasone treated pigs at market weight.

The relationships between the level of skatole in backfat, the rate of skatole metabolism in isolated liver microsomes, hepatic cytochrome P450IIE1 content and mRNA levels were investigated in Large White ✕ Landrace (LW) and the Meishan ✕ Landrace (M) breeds. A method based on thin layer chromatography was developed and used for measurement of microsomal skatole metabolism. Skatole metabolism by liver microsomes was inhibited by diallyl sulphide, a specific inhibitor of cytochrome P450IIE1 but not by inhibitors of other P450 isoforms. We have shown that the rate of skatole metabolism by liver microsomes was proportional to the microsomal P450IIE1 content. In LW pigs there was considerable variation in cytochrome P450IIE1 expression and P450IIE1 protein level and there was a significant negative correlation between backfat skatole level and hepatic microsomal cytochrome P450IIE1 content. Pigs exhibiting low P450IIE1 content in general also showed low levels of P450IIE1 mRNA. These results show that the levels of deposition of backfat skatole in LW pigs are inversely related to the rate at which skatole can be metabolized by liver microsomes, and this in turn depends on the level of expression of cytochrome P450IIE1 mRNA in the liver. In the M breed generally the P450IIE1 protein and mRNA levels were very low and backfat skatole level was high. However the skatole level varied over a 10-fold range and there was no significant correlation with P450IIE1 protein or mRNA content. The M breed was shown to express high levels of the multidrug resistance protein in liver, and it is suggested that export of skatole from liver via this transport protein may be an additional factor regulating backfat skatole in M pigs, but not in the LW breed.

Data were available for 160 sheep (50 Suffolk males, 50 Suffolk females, 40 Texel males and 20 Charollais males). One-fifth of animals within each breed and sex were slaughtered at each of 14, 18 or 22 weeks of age and two-fifths slaughtered at 26 weeks. After slaughter linear measurements were taken on the carcass. The left side of each carcass was then separated into eight joints and each joint dissected into lean, bone and fat. Five muscularity measures (three for the longissimus thoracis et lumborum (LTL) muscle, one for the hind leg and one for the whole carcass) and one of the shape of the LTL cross-section (depth: width) were calculated. With the exception of one measure for the LTL, muscularity increased with growth. Rates of increase in most measures were higher in Texels than in each of the other breeds, but were not different between the male and female Suffolks or between the Suffolk and Charollais lambs. Increases in most muscularity measures at a constant live weight were associated with increases in lean to bone ratio and carcass lean content. Associations with fat content were either non-significant or negative. Relationships with lean distribution were non-significant or weak. Correlations between the three measures of muscularity for the LTL were high. Correlations between the whole carcass measure and those within different regions were moderate to high in the Texels but lower in the Suffolk and Charollais breeds. The same was true for correlations between the LTL measures and hind leg muscularity. If muscularity throughout the carcass is to be described effectively, measures in more than one region may be required, particularly in the Suffolk and Charollais breeds.

The concentrations of growth hormone (GH), insulin (Ins), tri-iodothyronine (T3) and thyroxine (T4) in blood samples of growing yaks during different bimonthly seasons were determined by radioimmunoassay. The changes of body weight of growing yaks and composition of grass grazed were measured accordingly. The seasonal changes of hormones were significant (P < 0·01 or P < 0·05). Within season, the variances of hormones depended upon the different growing stages. The body-weight gains in the different groups varied in different seasons, increase being significant in May, July and September, decrease being significant from January to May. Correlation analysis indicated that T4 concentration had a significant positive correlation with the body weight of the growing yaks(r = 0·2509, P < 0·05) and other hormones did not have any significant correlation with body weight. The results showed that the annual cycle of weight loss and gain was attributed to the seasonal change of nutrition status. The seasonal change of the assayed hormones depended on the grass growth.

Factors responsible for breed- and depot-specific differences in the development of lipogenic enzymes, and hence lipogenic capacity of adipocytes, in sheep adipose tissue have been investigated using a serum-free cell culture system. Effects of insulin, tri-iodothyronine and exogenous lipid on the development in vitro of the lipogenic enzymes glycerol 3-phosphate dehydrogenase (G3PDH), fatty acid synthetase (FAS), NADP-malate dehydrogenase (ME), glucose 6-phosphate dehydrogenase (G6PDH), and isocitrate dehydrogenase (ICDH) in omental and subcutaneous pre-adipocytes from Lacha and Rasa Aragonesa lambs were investigated. Addition of insulin plus tri-iodothyronine caused pre-adipocyte differentiation, which was enhanced by addition of a lipid supplement. G3PDH activities achieved by differentiation of pre-adipocytes in vitro were similar to those found in vivo; furthermore after differentiation in vitro adipocytes from Rasa Aragonesa lambs had a greater G3PDH activity than adipocytes from Lacha lambs, as found in vivo. In contrast activities of FAS, G6PDH and ME achieved by differentiation in vitro were much greater than those found previously in vivo. While breed- and depot-specific changes in G6PDH observed after differentiation in vitro were similar to those observed in vivo, changes in FAS induced in vitro differed from those found during development in vivo. The study shows that pre-adipocytes from Rasa Aragonesa and Lacha lambs have intrinsic depot- and breed-specific differences in their ability to differentiate and express lipogenic enzymes. The combination of insulin, tri-iodothyronine and a lipid supplement appears to be sufficient to account for in vivo G3PDH activities but other factors are required to explain activities of FAS, G6PDH and ME found in vivo.

The aim of the present study was to evaluate water absorbing capacity and the drying and cooling rates of fur in farmbred male mink (Mustela vison) following 10 s of simulated diving. Comparisons were made between adult animals with summer and winter fur. The water loss from a swimming pool following diving in summer amounted to 146 (s.e. 14) g and 152 (s.e. 9) g in dry and wet mink, respectively (P > 0·05). During winter the corresponding values averaged 148 (s.e. 9) and 125 (s.e. 7) g, respectively (not significant: P > 0·05). No significant differences between summer and winter were found for dry mink. In wet-coated mink, on the other hand, water loss from the swimming pool was significantly greater (P 0·05) in summer than in winter. Drying of the fur was slow and significantly (P 0·05) affected by season so that half of the 100 g water absorbed by fur evaporated within 20 min during winter (at –2°C) whereas in summer (at +18°C) it took 60 min. A slower drying rate in summer could be benefical as it allows long-term body cooling in warm environment. Cooling constants of winter-coated dry mink (0·01955 (s.e. 0·00183) per min) were not significantly different (P > 0·05) from those of winter-coated wet mink (0·02091 (s.e. 0·00144) per min) indicating that energy costs of wet fur after diving are not critical for the survivial of the mink during winter.

Muscle chemical analysis and muscle identification both were attempted by using visible and near infrared reflectance spectroscopy (NIRS). Seventy-eight beef muscles (m. longissimus dorsi) from Hereford cattle were used. The samples were scanned in a NIRS monochromator instrument (NIRSystems 6500, Silver Spring, MD, USA) in reflectance mode (log 1/R). Both intact and minced muscle presentation to the instrument were explored. Predictive equations were made using ISI software (Infrasoft International, Port Matilda, PA, USA) and muscle identification was performed by Principal Component Analysis (PCA) and Soft Independent Modelling of Class Analogy (SIMCA). The coefficient of determination in calibration (R2CAL) and standard error in cross validation (SECV) for the intact sample presentation were 009 (SECV: 15·6), 0·89 (SECV: 46·9), 0·48 (SECV: 23·9) for moisture (M), fat and crude protein (CP) on g/kg fresh weight basis respectively. R2CAL and SECV for minced sample presentation were 0·41 (SECV: 161), 0·92 (SECV: 43·4), 0·71 (SECV: 20·5) for M, fat and CP on g/kg fresh weight basis respectively. Qualitative analysis of optical information through PCA and SIMCA analysis showed differences in muscles resulting from two different feeding systems.

A 3 ✕ 2 factorial experiment with a total of 60 male castrated pigs, live-weight range 24 to 104 kg, was carried out to test three dietary levels of high fat rapeseed press cake in two crossbreeds differing in carcass lean. The six groups with 10 pigs each representing either crossbreeds of Landrace (LR) ✕ (LR ✕ Large White (LW)) (groups 1, 3 and 5) or Pietrain (Pi) ✕ (LR ✕ LW) (groups 2, 4 and 6) were each offered, ad libitum, diets without rapeseed press cake (groups 1 and 2), or with rapeseed press cake: 75 g/kg diet (groups 3 and 4) or 150 g/kg diet (groups 5 and 6). The press cake produced in a small oil press contained 341 g crude protein per kg dry matter (DM), 181 g ether extract per kg DM and 23·3 mmol glucosinolates per kg DM. Rapeseed press cake, particularly at 150 g (3·2 mmol glucosinolates) per kg diet, lowered food intake and weight gain, though only significantly in the Pi-sired hybrids. There were no effects of the diets on leanness, whereas the 550 g/kg of carcass lean of Pi-sired pigs was significantly higher than the 510 g/kg of LR-sired hybrids. Meat of the Pi-sired crossbreeds showed a lower pH (tendency), higher conductivity, lower impedance and higher drip loss. At 150 g/kg diet rapeseed press cake LR-sired crossbreeds showed the darkest meat and the Pi ✕ LR, LW hybrids the lowest sensory evaluation score. In LR-sired hybrids the rapeseed press cake diets increased the backfat polyunsaturated fatty acids (PUFA) to a lower degree (1·3% per 10 g rape oil increase in 1 kg diet) than in Pi-sired hybrids (2·6% per 10 g rapeseed increase in 1 kg diet). Using simple correlation coefficients, the sensory evaluation results were negatively correlated with carcass lean and tended to be so with meat fat PUFA content. Pigs should receive less than 2 mmol glucosinolates per kg diet corresponding to 50 to 100 g double zero rapeseed products per kg diet. Rape oil should be recommended according to the animals lean and fat status, respectively. Fatter pigs may receive a maximum of 40 g, leaner pigs a maximum of 20 g rape oil per kg diet.

Weaving behaviour involves the repetitive lateral swaying of the head, neck, forequarters and sometimes hindquarters of the horse and is generally believed to be indicative of poor welfare. The behaviour of six known weavers was recorded three times a day for 5 days in each of three different stable designs. These were a conventional loose-box, a conventional loose-box with a 1 m2 acrylic mirror and a conventional loose-box in which there was a grilled 1 m2 side window separating the resident horse from a non-weaving conspecific in an adjacent stable. Weaving and other stereotypic behaviours were significantly higher in the unmodified stable and during the late afternoon observation period. There was no significant difference in the amount of stereotypic behaviour recorded in the two modified stables. Significant differences in the behaviour patterns and location of horses during the study suggest that activity engaging with either a visual image of a horse or a hay net is associated with a reduction in weaving and other repetitive activities in the stabled horse.

An experiment was performed to measure the response of young pigs to dietary tryptophan (TRP) concentrations and environmental temperatures. Seventy-two entire male Large White ✕ Landrace pigs were assigned to one of six dietary treatments (2·90 (T1), 2·46 (T2), 2·01 (T3), 1·57 (T4), 1·12 (T5) g/kg and T5 + supplemented TRP (T6)) and one of three temperature treatments (20, 25 and 30°C) at a mean starting live weight of 14·38 (s.e. 0·201)kg. Animals were given ad libitum access to food until a final weight of 26·42 (s.e. 0·479) kg. There were no significant interactions between temperature and dietary TRP on any production variable. There was a significant (P < 0·05) quadratic improvement in the rate of live-weight growth (ADG) as the concentration of dietary TRP increased and as the temperature decreased. However, the response to increasing dietary TRP was independent of the environmental temperature. Maximum ADG was attained on T2 (0·498 (s.e. 0·023) kg/day) and at 20ºC (0·412 (s.e. 0·024) kg/day). Final live weight was a significant (P < 0·001) covariate for ADG and food intake (FI) responses. With TRP as a precursor for serotonin, a neurotransmitter that regulates appetite, it was anticipated that food intake would be affected with decreasing dietary TRP levels. However, there was no response in daily food intake to decreasing TRP concentration. This lack of response in appetite to dietary TRP may have been a result of an increasing TRP to large neutral amino acid ratio, which is known to correlate with an increase in serotonin synthesis. Total heat loss followed a similar response to FI. The gain per unit of food consumed was significantly (P < 0·001) reduced as the TRP content of the diet was decreased. The most efficient treatments were T1 (506 (s.e. 1·90) g gain per kg food) and T2 (495 (s.e. 23·2) g gain per kg food) while the worst was T5 (237 (s.e. 22·3) g gain per kg food). There were significant quadratic responses to dietary TRP in protein content of the empty body (P < 0·05) and the rate of protein retention (PR) (P < 001) but only PR was affected by temperature (P < 001). Both temperature (P < 0·05) and dietary TRP (P < 0·001) had a significant effect on the lipid content of the body but only temperature affected the rate of lipid retention, with a significantly (P < 0·001) lower rate at 30 oC. The efficiency of TRP utilization improved with increasing temperature. It was lowest at 20ºC (0·60 g TRP per kg protein) and highest at 30ºC (0·86 g/kg), while the mean efficiency for pigs between 14 and 26 kg live weight, at thermoneutrality (25°C), was close to 0·71 g/kg.

Effects of open field testing and associated handling (including blood sampling) v. handling (with blood sampling) alone on adrenocortical reactivity were investigated in piglets around weaning. After weaning at day 28, piglets were mixed to form eight replicates with three litter each and kept on slatted floors. Treatments were open field/novel object testing and associated handling (OFT + H) v. handling alone (H) (no. = 40). Testing took place on the following days (weaning day 0): -4, 0, 1, 4 and 8 (no. = 16). The open field/novel object test lasted 10 min and blood was sampled by venipuncture before and after the test and/or handling procedures. In the first blood sample, plasma concentration of cortisol did not differ between OFT + H and H piglets. In the second blood sample, however, OFT + H piglets had a higher concentration of cortisol and a larger increase in cortisol than H piglets (P < 0·01). In the first blood sample the concentration of cortisol was affected by day (P < 0·05), with concentration on day -4 being lower than those on day 0, 1, and 4 and the concentration on day 8 was lower than the concentration on day 0 as well. However, no differences were found between days for the second blood sample nor the adrenocortical reactivity. In conclusion, the increase in pre-treatment cortisol in the first 4 days after weaning as well as the lack of changes in the adrenocortical reactivity after weaning suggest that the temporal development of HPA activity and reactivity in piglets after weaning are comparable with other, more standardized long-term stressors. Exposure to an open field/novel object test and associated handling results in higher adrenocortical reactivity than handling alone but the latter (including blood sampling) in itself accounts for proportionately 0·74 of the cortisol response.

The effect of two dietary electrolyte balance (dEB, Na+ + K+ – Cl-) levels (–135 and 145 mEq/kg diet) on heat production, energy and nitrogen retention in piglets was assessed. The experiment consisted of a 13-day adaptation period and a 7-day balance period in two open-circuit climate respiration chambers. Nine groups of three (4 weeks old) crossbred barrows were assigned to one of two diets (five and four groups for –135 and 145 mEq/kg dEB diets respectively). During the balance period, diets were provided at 2·3 times the energy requirement for maintenance in two equal meals daily. Total heat production for each group was determined every 9 minutes from the exchange of CO2 and O2. Faeces and urine mixture was quantitatively collected during the balance period to measure energy and nitrogen balance. Total heat production and metabolizable energy costs for maintenance tended (P 0·10) to be higher in the 145 mEq/kg dEB group (681 and 443 kJ/kg0·75 per day respectively) than in the –135 mEq/kg dEB group (660 and 412 kJ/kg0·75 per day respectively). Differences in total heat production between the two dEB groups mainly occurred in the daytime (light period), when significance level was P 0·01. The respiratory quotient and energy retention as fat were numerically (but not statistically significantly) lower in the 145 mEq/kg dEB group compared with –135 mEq/kg dEB. In conclusion, energy balances were similar for both treatments. However in the daytime (light period), piglets needed more energy for maintenance after ingesting a diet with a dEB level of 145 mEq/kg compared to a diet with a dEB level of –135 mEq/kg at a restricted feeding level.

To determine how weaning date affected productivity in deer farming systems, calf growth rate, hind conception date, and hind condition were monitored on 10 New Zealand deer farms located in Otago and Southland, from February/March until August/September in 1999 (no. = 551 hind-calf pairs) and 2000 (no. = 414 pairs). On each farm, in both years, half of the hind-calf pairs were separated for early weaning (mean date 11 March; range 25 February to 17 March), while the other half remained together for late weaning (mean date 28 May; range 12 May to 10 June). Deer in both treatments on each farm were of similar age and genotype and stags were added to hind groups on the same day in March. Calves were weighed in February/March, May/June and August/September. Scanning of hinds to determine date of conception was carried out in June.

Climatically the 2 years were very different with a summer drought preceding observations in 1999, nevertheless similar effects of weaning date were observed in both years. Calves weaned early gained less weight than the late-weaned calves (142 v. 210 g/day in 1999, and 131 v. 166 g/day in 2000) between February/March and May/June (P < 0·001). However mean conception dates were earlier in the early-weaned hinds compared with the late-weaned hinds (by 12 days in 1999 and 7 days in 2000,P < 0·001). Hind condition scores in May/June were higher for the early-weaned hinds compared with the late-weaned hinds (by 0·5 score units in 1999 and 0·3 score units in 2000, P < 0·001). For all measures the effects of weaning date varied between farms (P < 0·001). It was concluded that farmers weaning early could expect a positive effect on hind conception date and winter hind condition and a negative effect on calf growth rate, but management could override negative effects of weaning early or late.

A trial was conducted to compare the growth performance and carcass characteristics of 720 growing pigs housed in one of three different finishing systems: outdoor paddocks, straw yards and fully slatted pens. Two genotypes were used: ‘indoor’ (progeny of Large White ✕ Landrace sows mated to Large White boars) or ‘outdoor’ (progeny of part-Duroc or part-Meishan sows, mated to Large White boars). Groups of 20 pigs were reared from an average of 30 to 80 kg live weight and given ad libitum access to a commercial specification diet. The outdoor genotypes had significantly lower average daily gain than the indoor genotype (682, 673 and 719 g respectively for part-Duroc, part-Meishan and indoor-type pigs, P 0·01). Part-Meishan genotypes had significantly higher backfat levels than the indoor genotype (P 0·05), with an intermediate value for part-Duroc pigs (22·6, 21·1 and 21·8 mm respectively). Values for food conversion ratio were significantly higher for combined outdoor genotype groups when compared with the indoor genotype (2·76 v. jt>2·62, P 0·05). Average daily gains of pigs in straw yards and outdoor paddocks were significantly higher than for those in fully slatted pens (736 and 675 v. 627 g, P 0·01 respectively). Food conversion ratio was similar for pigs in outdoor paddocks and fully slatted pens, but significantly lower for those in straw yards (2·77 and 2·75 v. 2·55, P 0·01 respectively). Backfat depth (P1 + P3 mm) was significantly greater for animals finished in straw yards compared to those in outdoor paddocks (22·2 v. 20·6 mm, P 0·05) and intermediate for those finished in fully slatted pens (21·5 mm). Interaction between finishing system and genotype did not occur to any major degree, hence it appears unnecessary to specify a particular genotype for a particular finishing system. It was concluded that pigs of the outdoor genotype had a lower growth performance compared with the indoor genotype. Finishing systems however may have been confounded by other factors so that no clear recommendations can be made as to the optimum finishing system.

To measure the effect of stage of maturity of whole-crop (WCW) on its composition, digestibility and feeding value winter wheat was harvested at different maturities in two successive years. In year 1 WCW was harvested at 301(low dry matter (DM)) and 511(high DM) g DM per kg and ensiled and at 584 g DM per kg and treated with 40 kg urea per t DM before being stored (urea-treated WCW). Part of the high DM WCW was treated with an additive containing Lactobacillus buchneri at harvest. In year 2 WCW was harvested at 321 (low DM) and 496 (high DM) g DM per kg and ensiled before both crops were offered to the cows with or without a fibrolytic enzyme sprayed on the forage just before feeding. In both years the WCW was offered ad libitum in a 2: 1 WCW: grass silage DM ratio with 10 kg fresh weight concentrates per day to 40 early-lactation Holstein-Friesian cows in a 13-or 15-week production study with a continuous design and to four fistulated lactating cows in a 4 ✕ 4 Latin-square experiment for measurement of diet digestibility. In both years neutral-detergent fibre (NDF) content decreased and starch content increased with advancing maturity. In the production trials, DM intake increased (P 0·01) with advancing maturity but milk yield was not significantly affected. Milk protein yield was increased by urea-treated WCW. The additives had no effect on food intake or milk production. In year 1, digestibility of all fractions except starch was lower for high DM WCW than low DM WCW but for urea-treated WCW only the digestibility of starch and energy was lower than digestibility of the low DM WCW fractions. The inoculant had no significant effect. In year 2 crop maturity had no significant effect on digestibility but the enzyme reduced the digestibility of neutraland acid-detergent fibre (NDF and ADF, P 0·05). In year 1, each of the forage mixtures was offered to sheep at 12 g DM per kg live weight per day. There were significant treatment effects on the digestibility of DM (P 0·05) and organic matter (OM) (P 0·01) and on DOMD (digestible OM in the DM) (P 0·01) with the highest values being obtained for urea-treated WCW and the lowest for the inoculant-treated high DM WCW. Digestibility coefficients for NDF and ADF were highest for the urea-treated WCW while starch digestibility was essentially complete for all the WCW treatments. The metabolizable energy value (MJ/kg corrected DM) of the WCW decreased with advancing maturity when measured with both the lactating cows (10·4, 9·3 and 9·0) and the sheep (11·4, 10·8 and 10·3) in contrast to the predictions based on the chemical composition (9·6, 10·4 and 12·4). It is concluded that food intake increases with advancing crop maturity but milk production responses are small. Effects on digestibility were inconsistent but the energy value measured in the cows fell with advancing maturity in both years. The increase in crop yield per ha with advancing maturity is likely to be the most important factor influencing the decision to harvest later. The silage additives tested were not beneficial.

Five hundred and eighty-four Pannon White kits of 73 newborn litters were submitted to one of five treatments. Control litters (SS) were nursed once a day for 35 days post partum (traditional method of nursing). DD litters were raised by two does and the kits were nursed both in the morning and in the evening until day 35 post partum. DS litters were nursed twice a day for 23 days, and then once a day until weaning at 35 days. Part of the DS litters were nursed at 08:00 and 20:00 h (i.e. every 12 h, DS12), the rest were nursed at 08:00 and at 16:00 h (DS8). Kits of the fifth treatment (D0) were nursed twice a day until day 23, and then immediately weaned.

Rabbit kits that were nursed twice a day (DD, DS12, DS8, D0) consumed on average 1·89 more milk compared with SS individuals until day 23 (overall treatment effect P < 0·001). The 21-day body weight of these young was 1·7 times greater than that of the SS kits (overall P < 0·001). D0 rabbits were weaned early and their growth curve showed a slight break at this point. However, they compensated for this lag by the end of the fattening period. SS rabbits and DD ones were respectively the first and the last to start consuming solid food. The food consumption of DS rabbits was similar to that of DD until day 23 and from then until day 35 it was not significantly different from that of SS. After having been weaned on day 23, D0 kits consumed only very small quantities of pellets for 2 days. Afterwards their food intake increased abruptly. Rabbits that were nursed twice a day (DD, DS12, DS8 and D0) consumed more food as compared with the SS individuals throughout the total period of fattening (157 v. 137 g/day; P < 0·05). The weight at 10 weeks of age was 2·49 v. 2·88 kg (overall P < 0·001), respectively for SS and doublenursed (DD, DS, D0) rabbits. Nursing twice a day did not affect dressing proportion but the proportion of the carcass in the front part of the body decreased slightly (318 v. 323 g/kg; P < 0·05) while that in intermediate part increased (321 v. 307 g/kg; P < 0·05). Nevertheless, rabbits that were nursed twice a day had more (P < 0·05) perirenal + scapular fat and produced heavier livers. Total fat content of the empty body, however, was not significantly higher, with the one exception of the DD rabbits which had higher levels than any other group. The results of our experiment show clearly that the growth potential of rabbit kits is strongly limited by the milk availability during the first weeks post partum.