Estimates of co(variance) components were obtained for weights at birth, weaning and 6, 9 and 12 months of age in Muzaffarnagari sheep maintained at the Central Institute for Research on Goats, Makhdoom, Mathura, India, over a period of 28 years (1976 to 2003). Records of 5530 lambs out of 169 rams and 1631 ewes were used for the study. Analyses were carried out by restricted maximum likelihood (REML), fitting six animal models, including various combinations of maternal effects. Heritability estimates for weight at birth, weaning and 6, 9 and 12 months of age were 0·09, 0·21, 0·06, 0·10 and 0·14, respectively. Maternal heritability of body weight declined from 0·07 at birth to 0·02 at weaning. The maternal permanent environmental component contributed 10 to 11% to the total variance for all traits except weight at 12 months. A significant large negative genetic correlation was observed between direct and maternal genetic effects on weaning weight, suggesting the presence of antagonistic environmental, as well as perhaps genetic, effects in daughter and dam. Results suggest that maternal additive effects were only important in early stages of growth, whereas a permanent environmental maternal effect existed at all ages up to 9 months, probably as a carry-over effect of maternal influences present at weaning. Modest rates of genetic progress appear possible for all weights, but the presence of an antagonism between direct and maternal effects on weaning weight would complicate attempts to improve both by selection.

Sheep farming in the UK is characterized by a crossbreeding system where ‘Longwool’ sire breeds are mated with hill dam breeds, with the crossbred (F1) ewe lambs retained for mating to terminal sires. The F1 wether and terminal-sire cross lambs are marketed for meat. At selection, F1 females are typically assessed visually for type traits relevant to dam lines, and these traits could be considered as goal traits. Their offspring and their male sibs derive their value from carcass traits. This study investigated the genetic relationships between type (subjective) and carcass (objective) traits in F1 lambs, and their potential impact on genetic improvement within this production system. Bluefaced Leicester rams were crossed with Scottish Blackface and Hardy Speckled Face ewes to produce F1 (‘Mule’) lambs. The wether lambs (no.=2197) were selected for slaughter at a target condition (a carcass fat score of 2/3L) and a number of live and carcass traits were measured. Carcass dissection data were collected on approximately one-third of these wether lambs. The ewe lambs (no.=2423) were measured for similar live traits but at a fixed age (195±5·5 days). In addition, they were subjectively assessed for a number of functional and type traits. Genetic parameters among these traits were then estimated. Heritabilities for the ewe traits were generally moderate (0·18 to 0·31) and genetic correlations between the traits were variable, with some moderate to high correlations (favourable in direction) of growth/carcass traits with overall type traits. Live weight at slaughter in wethers was highly correlated to live weight at constant age in ewes (r=0·72). In the wethers, live, cold carcass and lean weight had moderately high heritabilities (between 0·26 and 0·46), and were positively correlated with slaughter age (≥0·79). However, age at slaughter in wethers was highly negatively correlated with growth/carcass and overall type traits in ewes (between −0·45 and −0·97), perhaps reflecting differences in maturity in lambs measured at a target fatness versus age. The correlations of most other type traits in ewes with wether traits were non-significant. These results show that the subjectively assessed type traits (at least as measured in this study) will not deteriorate, and some will in fact be improved, in a selection programme aiming to improve carcass merit.

Genetic parameters for carcass composition and meat quality traits were estimated in Scottish Blackface sheep, previously divergently selected for carcass lean content (LEAN and FAT lines). Computerized X-ray tomography (CT) was used to obtain non-destructive in vivo estimates of the carcass composition of 700 lambs, at ca. 24 weeks of age, with tissue areas and image densities obtained for fat, muscle and bone components of the carcass. Comprehensive measures of meat quality and carcass fatness were made on 350 male lambs, at ca. 8 months of age, which had previously been CT scanned. Meat quality traits included intramuscular fat content, initial and final pH of the meat, colour attributes, shear force, dry matter, moisture and nitrogen proportions, and taste panel assessments of the cooked meat. FAT line animals were significantly (P<0·05) fatter than the LEAN line animals in all measures of fatness (from CT and slaughter data), although the differences were modest and generally proportionately less than 0·1. Correspondingly, the LEAN line animals were superior to the FAT line animals in muscling measurements. Compared with the LEAN line, the FAT line had lower muscle density (as indicated by the relative darkness of the scan image), greater estimated subcutaneous fat (predicted from fat classification score) at slaughter, more intramuscular fat content, a more ‘yellow’ as opposed to ‘red’ muscle colour, and juicer meat (all P<0·05). All CT tissue areas were moderately to highly heritable, with h2 values ranging from 0·23 to 0·76. Likewise, meat quality traits were also moderately heritable. Muscle density was the CT trait most consistently related to meat quality traits, and genetic correlations of muscle density with live weight, fat class, subcutaneous fat score, dry matter proportion, juiciness, flavour and overall liking were all moderately to strongly negative, and significantly different from zero. In addition, intramuscular fat content was positively genetically correlated with juiciness and flavour, and negatively genetically correlated with shear force value. The results of this study demonstrate that altering carcass fatness will simultaneously change muscle density (indicative of changes in intramuscular fatness), and aspects of intramuscular fat content, muscle colour and juiciness. The heritabilities for the meat quality traits indicate ample opportunities for altering most meat quality traits. Moreover, it appears that colour, intramuscular fat content, juiciness, overall liking and flavour may be adequately predicted, both genetically and phenotypically, from measures of muscle density. Thus, genetic improvement of carcass composition and meat quality is feasible using in vivo measurements.

The objective of this study was to evaluate effects of natural zeolite (clinoptilolite) on nutrient digestibility, carcass attributes and performance of Holstein steers given a diet containing urea. Forty-five Holstein steers (309 (s.d. 11·2) kg) were given diets as follows: control diet based on maize and soya-bean meal (SBM); treatment 2 (T2), control diet (without SBM) containing 20 g/kg urea; treatment 3 (T3), control diet (without SBM) containing 20 g/kg urea and 30 g/kg zeolite. Just before feeding, ruminal ammonia levels were low in all treatments. At 2·5 h post feeding, steers given T2 and T3 diets had higher ( P<0·05) ruminal ammonia concentration than the control. At 5·5 h post feeding, steers on T3 diet had the highest ruminal ammonia concentration, which was higher ( P<0·05) than the value for steers given T2 diet. Plasma urea nitrogen level increased post feeding for all treatments. At 3 h post feeding, the level for steers given T2 diet was higher ( P<0·05) than those on control and T3 diets but at 6 h post feeding, the level was higher for steers on T3 diet. No differences ( P>0·05) were observed in dry-matter intake among treatments. Live-weight gain and gain: food ratio were highest ( P<0·05) for steers on the control diet, with no differences ( P>0·05) between steers given T2 and T3 diets. Including zeolite in a diet containing urea had no effect ( P>0·05) on total tract digestibility coefficients of dry matter, organic matter and crude protein but increased ( P<0·05) digestibility of neutral-detergent fibre and acid-detergent fibre. Hot carcass weight and kidney, pelvic and heart fat weight of steers were highest in control, intermediate in T3 and least in T2 ( P<0·05). No differences ( P>0·05) were found in longissimus muscle area and fat thickness over longissimus muscle among treatments. Including 30 g/kg of zeolite in a diet containing 20 g/kg of urea decreased ruminal ammonia nitrogen concentration, plasma urea nitrogen level and increased fibre digestibility but its effect on feedlot performance was negligible.

This study investigated the effects of 100 g/kg increments of crude protein (approx. 250 (P25) to 550 (P55) g/kg of crude protein) in paired iso-energetic diets on the growth performance of the juvenile Australian short-finned eel (1·83 (s.e. 0·01) g average wet weight). The highest growth response was obtained with treatment P45 followed by P35, P55 and P25. It appeared that food efficiency ratio (FER) increased with increasing crude protein content in low energy diets (treatments P25 and P35). However, 100 g/kg increase in dietary crude protein content (from 450 to 550 kg crude protein per kg diet) in high energy diets resulted in lower FER for treatment P55 than for the treatment P45. The protein efficiency ratio (PER, %) was higher in low protein:low energy diets (treatments P25 and P35) than that of high protein:high energy diets (treatments P45 and P55). The protein productive values (PPV, %) for treatments followed a similar trend to PER in this experiment. The lowest PPV was obtained by the treatment P55 and it was significantly different from that of the other three treatments. A proportional increase in dietary crude protein content in paired iso-energetic diets did not significantly change the whole body protein content. However, a small increase in whole body protein content with increasing dietary crude protein in each group was detected. In conclusion, the present study showed protein sparing effects of lipids and carbohydrates in the diets of the short-finned eel. Further studies specifically investigating the effects of dietary carbohydrate to lipid ratios at different protein levels would improve diet formulation and reduce nutrient impact in intensive recirculation systems.

Tree leaf meals (TLM) are increasingly used in the tropics to feed pigs. The nutritive value of the TLM of cocoyam (Xanthosoma saggitifolium), mulberry (Morus alba) and Trichanthera gigantea, their effect on the digestive tract and their fermentation rate in the large intestine, were determined in adult sows given diets containing 150 or 300 g TLM per kg. The TLM contained from 8·5 to 12·0 MJ digestible energy per kg dry matter (DM) and from 60 to 125 g digestible protein per kg DM. The digestibility was not affected ( P>0·05) by their rate of incorporation in the diet. The apparent ileal protein digestibility of the diets containing 300 g TLM per kg was also determined by the slaughtering method. It reached 80% for the basal diet and 54, 70 and 74% for the Trichanthera-, mulberry- and cocoyam-based diets, respectively. No diet effect ( P>0·05) was observed on the weight and length of the gastro-intestinal tract, with the exception of a heavier caecum in sows given the Trichanthera-based diet ( P<0·01). The pH of the gastric fluid of these sows was also higher ( P<0·001). The fermentation of the dietary fibre in the large intestine was evaluated by the gas technique using syringes. The cocoyam leaves presented the highest amount of total gas produced after fibre fermentation ( P<0·001). The ranking order of gas production was identical to that observed for the digestibility coefficients: Trichanthera <mulberry <cocoyam. In conclusion, TLM can represent up to 0·3 of a diet for sows. Their use in sow nutrition may be considered in tropical regions where protein sources are scarce.

In stall-feeding conditions, food diversity has been shown to increase an animal's motivation to eat and its level of food intake. This effect has also been suggested, but not demonstrated, for free-grazing animals. In free-grazing conditions, however, animals may have to search for the preferred plant species and this may reduce their intake rate. Moreover, the management of diverse swards faces a risk of overgrazing the preferred species and undergrazing the less preferred species, leading to resource degradation. We investigated the effect of food diversity on foraging behaviour and intake in grazing sheep, in interaction with the type of diversity (conterminal monocultures v. mixtures) and management (two monocultures offered simultaneously v. successively over time). Five treatments were compared with five groups of five dry INRA 401 ewes for five periods, using a Latin-square design: LOL=grazing a monoculture of Lolium perenne cv. Herbie (L); FES=grazing a monoculture of Festuca arundinacea cv. Florine (F); STRIPS=grazing conterminal monocultures of L and F, 0·5:0·5 by ground area, with animals having a free choice between both species; TIME=grazing L from 16:00 to 09:00 h and F from 09:00 to 16:00 h; MIX=grazing an intermeshed mixture of L and F. Sward height was maintained at 9 cm. Each period comprised a 5-day adaptation subperiod followed by a 5-day measurement subperiod. Dietary choices and intake were measured using n-alkanes, and grazing time was assessed using the Ethosys® recording system. Intake rate was calculated as the ratio of intake to grazing time. Intake in the monoculture treatments were higher than predictions made for housed animals given similar forages ad libitum, demonstrating that sward conditions were favourable for the expression of voluntary intake in all treatments. Intake was higher in LOL than in FES, this result being consistent with predictions for stall-feeding conditions. There was no difference in diet composition, foraging behaviour and intake between the bispecific treatments (STRIPS, TIME and MIX). Intake was higher in the bispecific treatments than in LOL (1666 v. 1492 g digestible organic matter per day, P<0·001). Grazing time was higher in STRIPS and MIX than in LOL (420 and 430 min respectively v. 366 min, P<0·01). Dry ewes increase their intake when offered a choice of herbage species at pasture, this being mediated via an increase in grazing time rather than an increase in intake rate. There was no interaction with type of diversity or type of management.

The presence of DNA fragments in tissues from rabbits given genetically modified (GM) soya-bean meal (solvent extracted) was investigated by using the polymerase chain reaction (PCR) approach. Moreover, the possible effects on cell metabolism were evaluated by determination of several specific enzymes in serum, heart, skeletal muscle, liver and kidney. The chloroplast sequence for tRNA Leu by using the Clor1/Clor2 primers designed on chloroplast trnL sequence was clearly detected. On the contrary, two couples of species specific primers for conventional (Le1-5/Le 1-3 which amplifies the soya bean lectin gene) and genetically modified (35S1/35S2 which amplifies the 35S CMV promoter that is present in the genomic structure of GM soya bean) soya bean were not found in all samples. No differences in enzyme levels were detected in serum, but a significant increase of lactic dehydrogenase, mainly concerning the LDH1 isoenzyme was found in particular in kidney and heart but not in the muscle, thus suggesting a potential alteration in the local production of the enzyme. Finally, no significant differences were detected concerning body weight, fresh organ weights and no sexual differences were detected.

Production and endoparasitism of first grazing season Holstein heifers and steers were investigated over two grazing seasons. Studies were conducted on low-lying peaty soil. In year 2000, 40 animals were included in a 2×2 factorial, replicated experiment with two sexes (steers v. heifers) and two stocking rates (SR): normal v. low (840 v. 420 kg live weight per ha at turn-out) in a set stocking grazing system. Mean grass heights over the entire season were 6·3±4·8 cm (mean±s.d.) at normal SR and 9·8±6·1 cm at low SR. Mean daily live-weight gain during grazing was significantly (P<0·001) lower at normal SR (256±147 g) compared with low (468±142 g) but sex did not significantly affect the daily gain. Serum pepsinogen levels, indicating uptake of gastric nematodes, were higher at normal SR and consistently higher in steers compared with heifers, although not significantly. In 2001 the experiment included 80 animals in a 2×2 factorial experiment with two sexes (steers v. heifers), two grazing systems (set stocking and two-paddock rotation) and four replicates. Pasture quality was low, 570 g digestible organic matter per kg organic matter and 139 g crude protein per kg dry matter on average, independent of grazing system. Mean daily live-weight gain was not significantly affected by grazing system. A tendency (P=0·07) to lower daily gain for the heifers than for steers was observed (427±161 g v. 474±138 g). Lower levels of pasture contamination with parasites were observed in the paddocks without grazing up to mid July but otherwise rotation did not prevent parasite infections. It is concluded that first grazing season steers and heifers have the same potential for growth when grazing marginal areas with low pasture quality. Set stocking or the two-paddock rotation scheme did not affect productivity or level of parasite infection at the end of season. Parasite infections became a problem at high SR. SR is an important factor for both daily live-weight gain per animal and total production per ha. However, due to the very heterogeneous structure of marginal areas there is a need for other indicators than kg live weight per ha at turn-out in order to define a clear relationship between stocking rate and production.

A detailed investigation was conducted to identify the main factors influencing the current poor reproductive performance in dairy herds in Northern Ireland. Nineteen herds were selected and a comprehensive database was established, comprising detailed information collected over a 2-year period. Milk progesterone monitoring (no.=1423 cows), based on twice weekly sampling, was included in this on-farm investigation. The mean interval from calving to commencement of luteal activity was 30·1 days and 13·4% (184/1378) of these cows had not commenced luteal activity by day 50 post partum. In addition, there was a high incidence of abnormal progesterone profiles: delayed ovulation type I; 15·6% (242/1388), delayed ovulation type II; 11·7% (125/965), persistent corpus luteum type I; 19·4% (212/1121) and persistent corpus luteum type II; 11·9% (70/619). Delayed commencement of luteal activity and abnormal profiles were associated with reduced fertility performance manifested as increased interval to first AI service and ultimately prolonged calving interval. Delayed commencement of luteal activity and abnormal progesterone profiles, with the exception of ‘delayed ovulation type II’ profiles, were not associated with lower conception rates. Assistance at calving was associated with delayed commencement of luteal activity. Delayed commencement of luteal activity and delayed ovulation types I and II profiles were associated with indicators of nutritional stress and poorer production performance in early lactation. Retained foetal membranes were strongly associated with prolonged luteal phases (persistent corpus luteum types I and II profiles). While hormonal therapy may prove useful in treating cows with abnormal milk progesterone profiles, the prevention and treatment of associated diseases and the implementation of good management practices are likely to be more rewarding.

The objective of this study was to develop accurate mathematical-statistical functions to estimate body composition of live pigs between 20 and 140 kg weight from total body water (TBWA) determined by the deuterium dilution technique. Chemical body compositions during the growth period are essential input parameters for biological pig growth models, which are used to estimated the nutrient requirements, improve the entire production system, determine optimal slaughter weight, optimize selection for food intake, etc. In the present study, 48 pigs (17 female and 31 castrated males) were used in an experimental station to obtain protein, lipid, ash and water content at 20, 30, 60, 90, 120 and 140 kg live weight. At each target weight, body water of the animals was determined by the deuterium dilution technique. Eight pigs of each live-weight group were slaughtered and chemically analysed. Water content of the empty body decreased from 74 to 53%, whereas lipid content rose from 7 to 30%. Between 20 and 30 kg body weight, protein content increased from 16 to 17% and thereafter decreased to 16%. Ash content was constant at 3%. To estimate body composition of the remaining animals from TBWA (%) determined by deuterium dilution technique, two sets of exponential prediction functions were used to describe the relationship between chemically analysed body components and TBWA (%). The first set of prediction functions fitted one intercept for the entire growth period and the second set of prediction functions fitted a different intercept for each weight class. Correlation coefficients between estimated and chemically determined empty body water, lipid, protein and ash for the first set of functions were 0·93, 0·86, 0·83 and 0·65, respectively. The second set of prediction functions showed higher accuracy (2 to 10%), but had the disadvantage of non-continuous estimates over the entire growth period. In contrast, by using the first set of prediction functions, a continuous accurate estimation of body composition of live pigs was obtained over a large range of growth (20 to 140 kg) based on deuterium dilution space.

Days open data from 113 569 lactation records in 774 Spanish Holstein herds were analysed using standard linear models under two different editing procedures, and with two alternative methodologies that account for censoring: a censored linear model (CLM) and a Weibull survival analysis (SA) model. The first editing procedure excluded from the linear model all censored records for days open (LMnc), and the second defined days open as days from calving to the last known insemination or culling date, treating censored records as complete (LM). Sire variance estimates for days open were 61, 70 and 139 for LMnc, LM and CLM, respectively, and 0·026 for SA on a logarithmic scale. Heritability estimates were 0·05, 0·06 and 0·08 with LMnc, LM and CLM, respectively. Rankings of sires varied between methodologies: sire evaluations from LMnc and LM had rank correlations with evaluations from SA equal to −0·65 and −0·82, respectively, and of 0·71 and 0·87 with evaluations from CLM. The rank correlation between evaluations from SA and CLM was −0·98, suggesting stronger agreement of sire rankings between models that take censoring into account.The SA model had a better predictive ability of daughter fertility at early stages of lactation than the other methods, as measured by chi-squared statistics for predicted pregnancy status at 75, 103, 140, or 200 days post partum in a split data set. The CLM also predicted daughter fertility more accurately than any of the two standard linear models.

Most nutritional pig growth models are based on the deposition of whole body protein (P) and lipid (L) mass. Chemical analysis of the whole animal is the best method to determine body composition. However, this method is expensive, time consuming and the carcass is lost. Alternatively, P and L may be estimated using simple indicators that should be precise and easily accessible. Although empty body weight (EBW) is a good indicator for P (through the strong relation between water and P), L is more difficult to estimate. This study was carried out to evaluate the relationship between simple carcass measurements and L. Measurements included backfat thickness in vivo and at slaughter in the hot and cold carcass and the weight of carcass, organs and primal cuts. To maximize variations in adiposity a total of 30 females and barrows from two genotypes (Piétrain×(Landrace×Large White) and Large White) were slaughtered at body weights typically used in Europe (i.e. 90 to 150 kg) and ground for chemical analysis. Backfat mass (in combination with EBW) was the best indicator for L (L (kg)=0·0590×EBW (kg)+2·99×backfat mass (kg), R2=0·96). Different backfat thickness measurements were highly correlated and appeared reasonable indicators for total backfat mass. Backfat thickness measured in the hot carcass between 3rd and 4th last lumbar vertebra at 8 cm from the mid line was the second best indicator for L (L=(0·0855+0·0073×backfat thickness)×EBW, R2=0·94). On average, 18% of total body lipids were located in the backfat. Although these equations can be used to obtain a reasonable estimate of whole body lipid mass, a significant genotype effect remained. Differences between genotypes in the partitioning of lipids between different tissues suggest that the quantification of an external lipid depot alone is insufficient to precisely estimate whole-body lipid mass across genotypes.

The aim of the present study was to evaluate the influence of breed and other factors (age, sex and season) on copper (Cu) accumulation by calves reared in a region in north-west Spain where pig slurry is widely used for slurry fertilization, and where cattle typically have hepatic Cu concentrations above the generally accepted safe-adequate levels. In December 2000 and August 2001, paired liver and blood samples were obtained at slaughter from 532 male and female Galician Blond, Holstein-Friesian and Galician Blond×Holstein-Friesian calves, aged between 6 and 10 months, from 434 different farms. Samples were acid-digested and Cu concentrations determined by ICP-OES. Holstein-Friesian calves showed significantly higher mean Cu concentrations both in the liver (80·6 mg/kg fresh weight) and blood (0·891 mg/l) than Galician Blond calves (50·4 mg/kg and 0·748 mg/l respectively) and crosses between the two breeds (61·3 mg/kg and 0·829 mg/l respectively). Holstein-Friesian was the breed with the highest percentage (42%) of calves with hepatic Cu concentrations above safe-adequate levels (25 to 100 mg/kg fresh weight) and Galician Blond the breed with the highest proportion (29%) of hypocupraemia during the winter sampling. Considering all breeds, hepatic Cu levels were higher in males (63·8 mg/kg) than in females (53·5 mg/kg) and significantly increased with age in summer. A significant three-way breed×sex×age interaction was observed for liver Cu but this may be attributable to the small number of animals in some groups, having a confounding effect on the analysis. A significant sex×age×season interaction was also observed which could indicate greater male dominance in summer, so that they consume more forage (and thus more Cu) than females. Calves slaughtered in winter showed significantly lower mean blood Cu concentration (0·703 mg/l) than calves slaughtered in summer (0·940 mg/l).

The objective of this study was to evaluate the effects of two sublethal doses (4 and 20 mg/kg live weight (LW); every other day) of gossypol on semen and hormonal characteristics of male rabbits. The experiment lasted 16 weeks and included two periods: a treatment period (first 8 weeks) where the animals were given the test materials, and a recovery period (second 8 weeks) where drugs were withdrawn. Results showed that LW and respiration rate (RR) decreased ( P<0·05) among animals that received gossypol, while rectal temperature increased ( P<0·05). Animals in gossypol treatment groups had decreased ( P<0·05) blood plasma levels of tri-iodothyronine (T3) and testosterone. This was accompanied by reductions ( P<0·05) in sperm concentration, total sperm output, percentage incidence of forward motility, total functional sperm fraction and semen initial fructose concentration. Gossypol however increased ( P<0·05) reaction time (i.e. decreased libido), percentages of dead sperm and abnormal sperm (AbSp) and altered acrosomes. Estimated weights of testes and semen ejaculate volume increased ( P<0·05) possibly due to increased water retention. Values of LW, RR, AbSp, and blood plasma T3 and testosterone returned to control levels after withdrawal of gossypol, while the effect of this drug on other parameters continued during the recovery period.

An experiment was conducted to examine the effects of mixed grazing of sheep plus cattle under continuous stocking of permanent pasture at different sward heights. The experiment had a 2×3 factorial design, with two sward surface heights (4–5 and 8–10 cm) and three combinations of animal species viz., sheep only, cattle only and sheep plus cattle. There were two replicate plots of each treatment combination and the experiment was conducted over 2 years consecutively. The sheep were Beulah Speckled Face ewes and their single Suffolk-cross lambs while the cattle were yearling Charolais-cross steers. Six ‘core’ steers and six ‘core’ ewes and their lambs grazed plots, as appropriately, while additional, non-experimental steers and ewes and their lambs were used to maintain sward heights. Each year the steers and the ewes grazed the pastures from May to October, while lambs were weaned and removed each year from the experiment in July. There was no significant effect of mixed grazing on live-weight gain of steers, but ewes had significantly higher live-weight gains on the sheep plus cattle treatment than on the sheep-only treatment (82 v. 61 g/day; P<0·001). The live-weight gain of the lambs was higher on the mixed grazing treatment than on the sheep only treatment on the 8–10 cm sward height treatment (243 v. 212 g/day; P<0·05) but there was no significant difference on the 4–5 cm sward height treatment (260 v. 250 g/day; P>0·05). The total output of live-weight gain per ha from steers, ewes and lambs was not significantly affected by animal species combination. It is concluded that while output per ha is not enhanced by mixed grazing by sheep and cattle when sward height is controlled, the live-weight gain of ewes is increased and the live-weight gain of lambs can be increased on taller swards.

The aim of this study was to investigate the effects of closing the piglets inside the piglet creep area during the first two or four sow feedings on piglet mortality from birth until weaning and piglet use of the creep area within the first 3 days after farrowing. A total of 96 sows in individual loose-housing farrowing pens were randomly allotted to one out of three groups: C0 – control (piglets not closed inside the creep area during feeding), C2 – piglets closed inside the creep area during the first two sow feedings after farrowing, C4 – piglets closed inside the creep area during the first four sow feedings after farrowing. Production results were registered on all sows, and the behaviour of 33 of the sows and litters were recorded, using instantaneous sampling every 10 min for 6 h during day 1, 2 and 3 after farrowing (farrowing=day 0). There were no effects of closing the piglets inside the creep area during sow feeding on piglet mortality, piglet activity or location. However, to make this conclusion reliable, this should be tested for several herds and with different types of creep areas. The piglets were lying increasingly more in the creep area from day 1 to day 3 (P<0·001), and at the same time mean proportion of the litter observed lying in close proximity of the mother decreased (P<0·001). How much the piglets used the creep area differed strongly between sows (P<0·05).