The objective was to determine the effect of age and dietary protein content on post-partum oestrous and ovarian cyclicity in autumn-lambing ewes. Twenty-four multiparous (age 4·5 (s.e. 0·61) years) and 24 primiparous (age 1·5 years) ewes which lambed on 28 October (s.e. 0·2) and were rearing 2·0 and. 1·7 (s.e. 0·13) lambs, respectively, were equally allocated to two dietary treatments in a 2 × 2 factorial design. Diets comprised a d libitum hay supplemented with concentrate (12·5 MJ metabolizable energy per kg dry matter (DM) and either 210 or 140 g crude protein per kg DM), offered at a daily allowance of 1·2 kg per ewe from lambing to weaning (18 December) and 0·4 kg per ewe thereafter. Throughout the study (3 November to 24 May) ewes were group-housed in straw-bedded pens under natural photoperiod at 57°N and their live weights and body condition scores were assessed at 2-week intervals. A raddled vasectomized ram was continually present with each group and ewes marked by the ram were recorded thrice weekly. Blood samples were obtained thrice weekly for measurement of peripheral progesterone concentrations and ovulation rate was determined by laparoscopy during January and March. There was no significant effect of dietary protein content on any of the variables measured. For multiparous and primiparous ewes, mean live weights and body condition scores at lambing were 79·5 (s.e. 1·41) v. 58·4 (s.e. 1·54) kg (P < 0·001) and 2·5 (s.e. 0·05) v. 2·2 (s.e. 0·05) (P < 0·001) and daily live-weight losses over the suckling period were 153 (s.e. 19·3) v. 85 (s.e. 21·1) glday (P < 0·05). Intervals from parturition to first overt oestrus were 39 (s.e. 3·2) v. 33 (s.e. 2·3) days and to the onset of ovarian cyclicity were 29 (s.e. 4·9) v. 25 (s.e. 1·5) days. Durations of ovarian cyclicity were 133 (s.e. 27·1) and 110 (s.e. 5·7) days (P < 0·01) during which 7·6 (s.e. 0·32) and 6·5 (s.e. 0·34) (P < 0·05) ovarian cycles were recorded respectively. Fifteen ewes had initial short cycles (≤10 days), six had prolonged cycles (≥21 days) and 11 had extended inter-luteal phase intervals (≥8 days). All ewes had recent ovulations at the January laparoscopy but only 19 multiparous and nine primiparous ewes had ovulations in March. Mean ovulation rates were: January 2·2 (s.e. 0·14) and 1·4 (s.e. 0·13) (P < 0·001), and March 1·6 (s.e. 0·23) and 1·2 (s.e. 0·15) for multiparous and primiparous ewes, respectively. It is concluded that, for ewes lambing at their normal time of mating, (i) the strong seasonal drive for reproduction results in the resumption of oestrous and ovarian cyclicity during the early post-partum period; (ii) initial luteal phases may be of short or extended duration; (Hi) there is no effect of age or dietary protein content, within the range studied, on the onset of ovarian cyclicity; and (iv) multiparous ewes experience a greater number of ovarian cycles and achieve higher ovulation rates than primiparous ewes.

In gene expression analysis, a key step to obtain informative data from reverse transcription quantitative PCR (RT qPCR) assay is normalization, that is usually achieved by ratio to correct the abundance of the gene of interest against that of an endogenous reference gene. The finding of such reference genes, ideally expressed in a stable way in multiple tissue samples and in different experimental conditions, is a non-trivial problem. In this work, a set of genes potentially useful as reference for gene expression studies in water buffalo has been identified and evaluated. In the first step, a publicly available Bos taurus expressed sequence tags database has been downloaded from the TIGR Gene Index and mined by some simple frequency algorithms to find out which tentative consensuses are present in a remarkable number of different cDNA libraries and, consequently, are more suitable to be included in a starter set of candidate reference genes. To validate the potential of such candidates for their use as normalizers in buffalo gene expression analysis, an RT qPCR analysis has been carried out, in which the expression stability of these genes has been evaluated on a panel of buffalo tissues and organs. Our results indicate that ribosomal proteins L4 and L5 and Gek protein encoding genes can be useful as normalizers to compare gene expression levels across tissues and organs in buffalo.

Hereford ♂ × British Friesian ♀ cows that had calved in September/October and were suckling mainly Charolais ♂ × calves were offered individually one of three planes of nutrition based on their estimated maintenance requirement during their first 150 days of lactation.

The mean daily intakes of metabolizable energy were 95·8, 71·5 and 52·1 MJ for the high, medium and low planes of nutrition respectively. Data were collected from 122 lactations. The mean 150-day cumulative milk yields of the cows were 1 355, 1 258 and 1 187 kg for the high, medium and low planes of nutrition respectively (P < 0·001). A i-kg increase in calf birth weight was associated with an increase in 150-day cumulative milk yield of 14·7 ± 2·17 kg (P < 0·001). Losses in live weight and condition score were significantly greater for cows given the low plane of nutrition during lactation (P < 0001).

Although there was a significant (P < 0·01) positive correlation between the growth rate of the calves and their dams' nutritional level during the winter there was evidence of compensatory growth at grass, since by the time of weaning in August, the plane of nutrition of the dam during the winter had no significant effect on the weight of the calves.

The experiment demonstrates that energy-deficient beef cows will attempt to maintain milk production at the expense of body reserves and that when supplementary solid food is made available to the suckled calves, their weaning weights are unaffected by the plane of nutrition of the dam during the winter.

The growth and carcass characteristics of semi-intensively reared Charolais × Ayrshire and Beef Shorthorn × Ayrshire cattle were studied. Charolais × Ayrshires grew faster while grazing, achieved slaughter condition at a higher live-weight and age and had leaner carcasses than Beef Shorthorn × Ayrshires. The practical significance of these results is discussed.

Foods produced from two cereal-legume cropping systems were evaluated in a 250-day growth trial using Friesian × Boran crossbred steers. Crops and crop combinations in cropping system 1 were oat-vetch (Avena sativa-Vicia dasycarpa; OV), wheat-trifolium (Triticum aestivum-Trifolium steudneri; WT), teff (Eragrostis tef) and chickpea (Pisum sp). Cropping system 2 differed from 1 in that maize-lablab (Zea mays-Lablab purpureus; ML) replaced ivheat-trifolium. Twenty-four steers (mean initial live weight 157 (s.d. = 4·5) kg were assigned randomly within weight group to four treatments. Treatments comprised ad libitum teff straw (TS) given alone (Tl), TS plus wheat middlings (WM) given at 0·01 M (body weight) (Tl), forages from system 1 fed in the order OV, WT and TS plus chickpea for 135, 48 and 67 days respectively (T3) or forages from system 2 fed in the order OV, ML and TS plus chickpea for 73, 147 and 30 days respectively (T4). The feeding period for each crop ofT3 and T4 was based on its contribution to the total dry matter (DM) yield of the cropping system. Apparent digestibility of DM measured by the acid-insoluble ash method was higher (P < 0·05) for T3 and T4 than for T2. DM intake was higher (V < 0·01) for steers on T2 resulting in 1 kg higher daily intake of digestible DM than for T3 and T4. Steers on T4 gained (average daily gain, ADG) more (P < 0·01) weight than steers on T3 (149 v. 85 g per head per day) but less (P · 0·01) than those on T2 (528 g per head per day). Steers on Tl lost 94 g per head per day. Food efficiency (kg yain per kg food) followed a similar trend as ADG. At the end of the trial, two steers from each treatment were slaughtered for carcass assessment and the remaining steers used in a realimentation study of 120 days and then slaughtered for carcass assessment. Steers which gained poorly during the 250-day trial (Tl, T3 and T4) exhibited compensatory gains of 497, 550 and 565 g per head per day respectively compared with 398 g per head per day for steers on T2. Carcasses from T2 yielded significantly more (P < 0·05) lean and fat than carcasses from T3 and T4. The results suggest that growing food crops in association with legumes has the potential of increasing cattle performance.

Fifty newborn Saanen kids were used to study the effects of inulin supplementation on faecal score, faecal pH, selected faecal bacterial population, BW, body temperature, haematological traits, selected health parameters and the incidence of diarrhoea. Kids were sorted by parity of their dams and multiple birth (twin or triplet) and assigned to one of the two groups (control: CG, and experimental: EG) at birth. Each group consisted of 25 kids. The groups were similar with regard to sex and birth weight. All kids were fed colostrum for the first 3 days after birth, and then the kids in EG were adapted to inulin supplementation by an increased dosage from day 4 to 7. Each kid in EG was supplemented with 0.2 g, 0.3 g, 0.4 g, 0.5 g and 0.6 g inulin on day 4, 5, 6, 7 and from day 8 to 28, respectively, whereas the kids in CG did not receive inulin. Faecal score and faecal bacterial population were not affected by inulin supplementation (P > 0.05). There were differences in faecal pH on day 14 (P = 0.01) and 28 (P<0.05), whereas no difference in faecal pH on day 21 (P > 0.05) was detected between groups. No differences (P > 0.05) in BW and haematological traits were found between groups. Body temperature did not differ on day 14 and 21 (P > 0.05), whereas there was a difference in body temperature on day 28 (P = 0.01) between groups. The numbers of kids with pneumonia and kids treated for pneumonia and diarrhoea were similar for CG and EG. Kid losses during the study were the same for CG and EG. The incidence of diarrhoea was not affected by inulin supplementation (P > 0.05). Inulin supplemented to kids did not adversely affect faecal score. The effect of inulin on faecal pH was not consistent. The results of our study suggested that daily dose (0.6 g) of inulin might not be enough to observe effects of it. Our data will be useful to determine the dose and timing of inulin supplementation in future studies investigating the effects of inulin on the parameters associated with performance and health status in kids and other young ruminants.

Guinea fowl production is increasing in developing countries and has a crucial role in the fight against poverty. However, the feed cost is very high, especially the soya bean meal cost, and farmers cannot afford to buy commercial feed. Consequently, animals do not receive feed adapted to their nutritional needs and they exhibit poor performance. The aim of this paper is to partially substitute soya bean meal by local by-products, discarded, in abundant supply and not used in human nutrition. French Galor guinea fowl (Numida meleagris) and local African guinea fowl (150 birds per breed) were reared for 16 weeks and fed the same starter diet for the initial 4 weeks. From 4 weeks of age, experimental birds from each breed were randomly assigned to three grower isoproteic and isolipidic dietary treatments, each containing five replications (floor pens); each replication included 10 birds of the same breed. The guinea fowl of each breed were fed either control grower diet using soya bean meal as the protein supplement GS, or trial grower diet GN (soya bean meal supplement partially substituted by 15% cashew nut (Anacardium occidentale) meal) or trial grower diet GH (soya bean meal supplement partially substituted by 15% hevea seed (Hevea brasiliensis) meal). The results indicated that hevea seed meal contained a high content of n-3 polyunsaturated fatty acids (PUFAs) (21.2% of total fatty acids (FAs)). The use of hevea seed meal in guinea fowl grower diet was found to exert no adverse effect on growth performance and carcass yield. However, the use of cashew nut meal led to negative effects on performance like daily weight gain and feed conversion ratio. Therefore, cashew nut meal cannot be considered as a suitable partial substitute for soya bean meal in diets. The use of hevea seed meal led to a very low abdominal fat proportion and low blood triglyceride and cholesterol content. Additionally, inclusion of dietary hevea seed meal resulted in guinea fowl meat enriched in PUFAs, especially n-3 FAs, thereby significantly improving the nutritional value.

The gene frequency of the halothane gene was estimated in nine British Landrace and Large White nucleus herds. Two hundred and sixty British Landrace and 186 Large White pigs purchased from these herd, to be used as foundation stock for a joint experiment on lean growth at the Physiology and Genetics Research Station, Edinburgh at Wye College, were test mated to homozygous halothane reactors (nn). One thousand six hundred and forty-six British Landrace and 1764 Large White offspring were given a 4-min halothane test at average ages of 76 and 50 days respectively. Maximum-likelihood estimates of the halothane gene frequency were 0·33 (s.e. 0·03) in British Landrace and 0·11 (s.e. 0·02) in Large White. Estimated proportions of reactors amongst heterozygotes (Nn) and halothane homozygotes (nn) were 0·00 and 0·70 in Large White, and 0·02 and 0·85 in British Landrace. There was significant heterogeneity between the herds for both breeds (P < 0·05). The proportion of halothane reactors in British Landrace herds has increased significantly (P < 0·05) from 0·13 in 1979 to 0·18 in 1982, and the proportion of Large White reactors has increased from zero to 0·01 in the same time period.

1. The reproductive performance of 128 first-lambing ewes born during 1966–71, and of 118 ewes kept on a twice-yearly lambing system during 1968–1972/73, in a commercial flock of Finnish Land-race sheep in Finland, was analysed.

2. The first-lambing ewes were exposed to the ram throughout the year, except in June and July. Out of 95 ewes born between January and May, 92 (97%) lambed at the age of 376·4 ± 29·9 days, and out of 20 born between July and September, 15 (75%) lambed when 323·8 ± 50·4 days old.

3. The average litter sizes at first lambing were 1·6, 1·9 and 2·6 for ewes with average ages of 324, 388 and 534 days, respectively; the 5-mo litter weights averaged 41·7, 45·7 and 70·5 kg per ewe for the three groups.

4. In the twice-yearly lambing system 55% of ewes lambed once within a calendar year and 45% lambed twice. The number of consecutive lambings and the number of lambs born per ewe per year were 1·52 ± 0·29 and 4·03 ± 1·18, respectively. The consecutive lambings of the 118 ewes, over a period of 1½ to 5½ yr, did not indicate any decline in reproductive performance.

5. The estimated lambing-to-conception interval in consecutive lambings was 116·6 ± 64·3 days; February had the lowest conception rate (0·7%) and November the highest (20·8%); April (16·5%) and September (15·5%) were similar.

6. Litter size was not affected by year, age of ewes, or lambing period. The mean lamb mortality up to 14 days of age, based on 1168 lambs born dead or alive, was 12·8% and the annual ewe wastage averaged 21·9%

7. For ewes which lambed twice within a calendar year, the lambing to conception interval was 71·7 ± 24·7 days. Such ewes produced 5·0±1·4 lambs per calendar year and the combined 5-mo weight of both litters was 168·2 ± 43·2 kg per ewe.

Pre-weaning mortality represents a major economic loss and welfare concern for the global pork industry. Caffeine administration prior to, or after, parturition positively affects metabolic parameters associated with survival in newborn animals. However, its effects on piglet viability and survival when administered within the first 24 h of life have not been evaluated. This study determined the effect of caffeine treatment during the 24 h postpartum period on piglet viability, growth and survival. Piglets received 30 or 0 mg of caffeine orally at birth or 8 to 12 h following birth and again at 24 h. Vitality, meconium staining and blood lactate were assessed at birth. Time to first reach the udder and suckle was recorded. Body weight and rectal temperature were measured at 10 min, 24 and 72 h after birth. A blood sample for analysis of serum immunoglobulin G was collected at 24 h, and BW and survival were monitored to 20 days of age. Caffeine had no effect on body temperature, blood glucose, serum immunoglobulin G concentration or weight (P > 0.05). However, when caffeine was administered at birth, it significantly increased 24 h mortality in piglets (P < 0.05). Piglet mortality between birth and weaning also tended to be higher for piglets receiving caffeine at birth (P = 0.063). These data demonstrate that caffeine administration to piglets at birth, but not 8 to 12 h after birth, impaired piglet survival. Further research into caffeine dosage and timing postpartum is required to establish its efficacy.

The pattern of food intake as a function of age, and live weight as a function of food consumed was examined from soon after weaning to maturity in groups of fine and strong wool Merino rams and Dorset Horn rams and wethers. Each group, which initially comprised 20 sheep and from which individuals were removed for slaughter at approximately 6-kg increments in live weight, was fed a pelleted ration ad libitum for 98 and 77 weeks for the Merino and Dorset Horn groups respectively.

The pattern of food intake was similar for all groups of sheep, in that food intake increased to a maximum at approximately 50 weeks of age and then declined with age with a regular oscillation superimposed on this curve. In all three groups of rams, but not in the Dorset Horn wethers, the oscillations in food intake were on an approximate annual cycle with a decrease in food intake in summer and an increase in winter.

Estimated mature live weights for the strong and fine wool Merino rams were 120·5 and 97·6 kg, and for the Dorset Horn rams and wethers 108·6 and 101·4 kg. Variation between breeds in the level of food intake, food efficiency and consequently the pattern of growth, was largely a function of mature size. The Dorset Horn rams were slightly more efficient at converting food to live weight than the wethers.

The Australian prime lamb industry is seeking to improve lean meat yield (LMY) as a means to increasing efficiency and profitability across the whole value chain. The LMY of prime lambs is affected by genetics and on-farm nutrition from birth to slaughter and is the total muscle weight relative to the total carcass weight. Under the production conditions of south eastern Australia, many ewe flocks experience a moderate reduction in nutrition in mid to late pregnancy due to a decrease in pasture availability and quality. Correcting nutritional deficits throughout gestation requires the feeding of supplements. This enables the pregnant ewe to meet condition score (CS) targets at lambing. However, limited resources on farm often mean it is difficult to effectively manage nutritional supplementation of the pregnant ewe flock. The impact of reduced ewe nutrition in mid to late pregnancy on the body composition of finishing lambs and subsequent carcass composition remains unknown. This study investigated the effect of moderately reducing ewe nutrition in mid to late gestation on the body composition of finishing lambs and carcass composition at slaughter on a commercial scale. Multiple born lambs to CS2.5 target ewes were lighter at birth and weaning, had lower feedlot entry and exit weights with lower pre-slaughter and carcass weights compared with CS3.0 and CS3.5 target ewes. These lambs also had significantly lower eye muscle and fat depth when measured by ultrasound prior to slaughter and carcass subcutaneous fat depth measured 110 mm from the spine along the 12th rib (GR 12th) and at the C-site (C-fat). Although carcasses were ~5% lighter, results showed that male progeny born to ewes with reduced nutrition from day 50 gestation to a target CS2.5 at lambing had a higher percentage of lean tissue mass as measured by dual energy X-ray absorptiometry and a lower percentage of fat during finishing and at slaughter, with the multiple born progeny from CS3.0 and CS3.5 target ewes being similar. These data suggest lambs produced from multiple bearing ewes that have had a moderate reduction in nutrition during pregnancy are less mature. This effect was also independent of lamb finishing system. The 5% reduction in carcass weight observed in this study would have commercially relevant consequences for prime lamb producers, despite a small gain in LMY.

The influence of the cloned-cattle meat diets upon reproduction in mammals was rarely studied. This study was performed to analyze the effects of the diets containing cloned-cattle (Korean native beef, Hanwoo) meat on the reproductive physiology in rats. The male and female rats were fed with the diets containing 5% or 10% of normal- (N-5 or N-10) or cloned- (C-5 or C-10) cattle meat during test periods. The rats fed with commercial pellets were used as control. Lower food consumption in normal- and cloned-cattle meat diet groups is detected in both male and female rats compared with that of control (P < 0.05, 0.01 and 0.001). No signs of cloned-cattle meat diets on male reproductive parameters are found in all groups, except for lower sperm deformity in C-5 group (P < 0.05) and higher testosterone concentration in C-10 group (P < 0.05), respectively. There are no significant test substance-related differences of Caesarean section and delivery in dams and external examination and physiological development test in neonate compared with control and normal meat groups. Based on these results, it can be postulated that there are no obvious negative effects on the reproductive physiology in rats fed with cloned-cattle meat diets compared to their comparators.

The experiments were conducted to investigate the effect of sire breed and production system on serum GH, insulin, prolactin, glucose and blood urea nitrogen concentrations in growing beef cattle. A total of 187 steers, representing a wide range of maturity types, was reared to slaughter on either the 16-month or 24-month production systems in experiment 1, and blood samples for hormone and metabolite determinations were collected at 3-monthly intervals. Experiment 2 compared only the extremes of maturity type, with four early- and four late-maturing animals on each production system. Blood samples from these animals were collected hourly for 10 h on 2 or more consecutive days at six different time periods during the growth of the animals.

Although significant between-breed differences in hormone concentrations were observed in experiment 1, there were no significant correlations between growth rate and circulating hormone concentrations. These results were largely borne out by the more detailed blood sampling used in experiment 2.

Differences did occur in live-weight gain, GH and insulin concentrations between production systems, although these were largely determined by the induced changes resulting from the imposition of a store period on the animals produced through the 24-month production system.

These results indicate that between-breed differences in growth rate cannot be accounted for by differences in circulating GH, insulin and prolactin concentrations. Rather, it appears that the hormones are primarily used to enable the animal to adjust its metabolism to changes in nutrient supply.

Two experiments were conducted to test different milking procedures for dual-purpose goats that would be suitable for smallholder farmers. In experiment 1, 105 East African and Galla does that kidded to singles were randomly assigned to three treatments: (a) milking in absence of kid and kid sucking residual; (b) milking in presence of kid and kid sucking residual; and (c) milking once a week and kid sucking all milk 6 days of the week. In experiment 2, 45 Galla does that kidded to singles were randomly assigned to three treatments: (a) weigh-suckle-weigh; (b) milking half udder while kid sucking other half and (c) kid sucking all milk in the evening and milking mornings. Measurements of milk yield, milk sucked and weights of kids were taken for 12 weeks of lactation.

Results were analysed using least-squares techniques for unequal subclass numbers. Milking in the presence of kids increased does' milk yield. This increase was attributed to the stimulation of milk let-down by the presence of kids. Although this method potentially provided most milk for dairy use, less residual milk was left to sustain growth of kids. Estimates of total milk yield by milking once a week underestimated milk yield potential of the East African and Galla breeds. Results indicated an appropriate method for estimating milk potential should combine both milked and sucked milk measurements. Restricting milk available to the kids reduced their growth rates and thus indirectly affected their maturing rates. No milking procedure proved to be superior all-around for the smallholder for milking goats. To resolve this dilemma, use of an optimizing technique including socio-economic weighting of milk for family use relative to milk for kids was proposed.

A total of 48 Duroc × (Large White × Landrace) gilts of 46.8 kg BW (86 ± 3 days of age) were used to investigate the effect of diet during the growing and finishing periods on growth performance and carcass, meat and fat quality. The control diet consisted of a commercial feedstuff and the granulated barley diet had that cereal as the single major ingredient. There were three treatments: (i) control diet provided from 45.6 to 127.8 kg BW (C group), (ii) control diet from 47.0 to 91.8 kg BW and granulated barley from 91.8 to 129.7 kg BW (C + GB group) and (iii) granulated barley from 47.9 to 93.1 kg BW and control diet from 93.1 to 135.1 kg BW (GB + C group). Each treatment was replicated eight times, with two pigs per replicate. The C group grew faster (P < 0.001) and had a better feed conversion ratio (P < 0.001) than the GB + C group, with C + GB being intermediate. Carcasses from C + GB gilts had higher backfat depth than those from C gilts, with GB + C being intermediate (P < 0.05). Also, the main joints (ham + shoulder + loin) had a higher (P < 0.01) yield in carcass in the GB + C group than in the C group, with C + GB being intermediate. The intramuscular fat (IMF) content was higher (P < 0.001) in loin from C + GB and GB + C gilts than in C gilts. The IMF of loin from C + GB gilts had higher (P < 0.05) C18:1n-9 and total monounsaturated fatty acid (FA) proportions than that from C gilts, whereas the C18:2n-6 and total polyunsaturated FA percentages were lower (P < 0.05) in C + GB gilts than in the remaining gilts. The total saturated FA percentage was lower (P < 0.05) in loin from GB + C than in that from C gilts. Hams from C + GB and GB + C gilts had higher (P < 0.05) C18:1n-9 and total monounsaturated FA proportions and lower C18:2n-6 and total polyunsaturated FA contents than those from C gilts. We can conclude that granulated barley provided during the growing or the finishing period improved some carcass and meat characteristics of heavy gilts desirable for dry-cured ham production.

The effects of forage type, breed type and sex on lamb growth and carcass composition, and their changes throughout growth, were measured. The three breed types were Scottish Blackface (no. = 31), Suffolk (no. = 28) and their reciprocal cross (no. = 30). The lambs were given ad libitum a pelleted ryegrass alone, pelleted lucerne alone or a choice of both. Each lamb was scanned using X-ray computed tomography to measure the weights of fat, lean and bone in the carcass at three proportions of mature body weight (0·30, 0·45 and 0·65). Live weights and food intake data were recorded weekly. Average daily gains in live weight and carcass tissues, food intake and efficiency were calculated for each lamb between degrees of maturity. Relationships between weight and food intake were investigated using a Spillman function.

Breed type had no effect on fat or lean proportion in the carcass but Scottish Blackface lambs had 1·04 times the carcass bone proportions of the Suffolk or crossbred lambs. Diet had no effect on carcass tissue proportions. The effect of sex on carcass composition changed with stage of maturity. Breed type and sex effects on intakes and gains in live weight and tissue weights were related to mature size differences. Scaling by (mature size)0·73 did not fully remove these differences. There were no effects of breed type, sex or diet on efficiency. Lambs on ryegrass had lower intakes (0·878 as great) and slower growth (0·851 as fast) than those on lucerne or the choice treatment. The mean proportion of ryegrass in the choice diet was 0·366 (s.e. 0·0273); it increased slightly with time. There was no breed type by diet interaction for any of the variables examined. The Spillman function described growth well and showed that there were no effects of breed type, diet or sex on efficiency.

The animal health and welfare status in European organic dairy production does not in all aspects meet the organic principles and consumers’ expectations and needs to be improved. To achieve this, tailored herd health planning, targeted to the specific situation of individual farms could be of use. The aim of this study was to apply herd health planning in a structured participatory approach, with impact matrix analysis, not previously used in this context, in European organic dairy farms and to assess changes in animal health and welfare. Herd health planning farm visits were conducted on 122 organic dairy farms in France, Germany and Sweden. The farmer, the herd veterinarian and/or an advisor took part in the farm discussions. The researcher served as facilitator. Baseline data on the animal health status of the individual farm, collected from national milk recording schemes, were presented as an input for the discussion. Thereafter a systematic impact matrix analysis was performed. This was to capture the complexity of individual farms with the aim to identify the farm-specific factors that could have a strong impact on animal health. The participants (i.e. farmer, veterinarian and advisor) jointly identified areas in need of improvement, taking the health status and the interconnected farm system components into account, and appropriate actions were jointly identified. The researcher took minutes during the discussions, and these were shared with the participants. No intervention was made by the researcher, and further actions were left with the participants. The number of actions per farm ranged from 0 to 22. The change in mortality, metabolic diseases, reproductive performance and udder health was assessed at two time points, and potential determinators of the change were evaluated with linear regression models. A significant association was seen between change in udder health, as measured by the somatic cell count, and country. At the first follow-up, a significant association was also found between change in the proportion of prolonged calving interval and the farmers’ desire to improve reproductive health as well as with an increase in herd size, but this was not seen at the second follow-up. The degree of implementation of the actions was good (median 67%, lower quartile 40%, upper quartile 83%). To conclude, the degree of implementation was quite high, improvement of animal health could not be linked to the herd health planning approach. However, the approach was highly appreciated by the participants and deserves further study.

Female domesticated yaks were artificially inseminated with semen taken from wild yaks and the offspring used to form a nucleus breeding herd of crossbred animals. The meat production of the first generation (F2 × F2) frombreeding within the nucleus herd was assessed by slaughter and carcass dissection of males. One group (no. = 14) was slaughtered at 6 months of age and the second (no. = 12) at 18 months. Crossbred yaks were significantly heavier (P < 0·01) at 6 months (74·7 (s.e. 10·41) kg v. 59·8 (s.e. 10·23) kg) and at 18 months (150·5 (s.e. 56·1) kg v. 117·7 (s.e. 17·4) kg) than domesticated ones. The killing-out proportion (0·47) was similar at both ages and for both groups of animals. Carcass weight, meat weight and the yield of prime cuts were higher for crossbred animals than for domestic yak at both ages.

Genomic selection has become increasingly important in the breeding of animals and plants. The response variable is an important factor, influencing the accuracy of genomic selection. The de-regressed proof (DRP) based on traditional estimated breeding value (EBV) is commonly used as response variable. In the current study, simulated data from 16th QTL-MAS Workshop and real data from Chinese Holstein cattle were used to compare accuracy and bias of genomic prediction with two methods of calculating DRP. Our results with simulated data showed that the correlation between genomic EBV and true breeding value achieved using the Jairath method (DRP_J) was superior to that achieved using the Garrick method (DRP_G) for simulated trait 1 but the reverse was true for simulated trait 3, and these two methods performed comparably for simulated trait 2. For all three simulated traits, DRP_J yielded larger bias of genomic prediction. However, DRP_J outperformed DRP_G in both accuracy and unbiasedness for four milk production traits in Chinese Holstein. In the estimation of genomic breeding value using genomic BLUP model, two methods for weighting diagonal elements of incidence matrix associated with residual error were also compared. With increasing the proportion of genetic variance unexplained by markers, the accuracy of genomic prediction was decreased and the bias was increased. Weighting by the reliability of DRP produced accuracy comparable to the evaluation where the proportion of genetic variance unexplained by markers was considered, but with smaller bias in general.