Trends in milk production, calving rates, and survival were monitored on a potential 5580 primiparous and multiparous Holstein-Friesian dairy cows across 14 Irish seasonal spring-calving dairy farms between the years 1990 and 2001. Over this period calving rate to first service (CALV1) reduced by 0·96% per year (55 to 44%; P< 0·001), calving rate to first and second service (CALV12) reduced by 0·84% per year ( 77 to 70%; P< 0·001) and herd average parity number reduced by 0·10 lactation per year (4·3 to 3·5; P<0·001). The proportion of North American Holstein Friesian (NAHF) genes in the cows increased by 5·5% per year (8 to 63%; P<0·001), while pedigree index for milk yield (PIMILK) of the cows increased by 25 kg per year ( P<0·001). The predicted difference of the sires of the cows for calving interval and survival increased by 0·5 days (P<0·001) and reduced by 0·12% ( P<0·001) per year, respectively. A negative association was found between increased phenotypic milk yield, NAHF and PIMILK and reduced calving rates as assessed by CALV1 and CALV12. Increased proportion of NAHF genes exhibited a negative effect on survival ( P<0·001) whereas increased levels of heterosis had a positive impact on survival ( P<0·001). The results of the present study indicate that in seasonal calving herds in Ireland a need for direct selection on traits related to fertility and survival is required to arrest and reverse the declining trends in calving rates and survival.

The objective of this study was to investigate the effects of strain of Holstein-Friesian cow, pasture-based feeding system (FS) and their interaction on milk production, dry matter (DM) intake and energy balance over 3 years consecutively. The three strains were: high milk production North American (HP), high fertility and survival (durability) North American (HD) and New Zealand (NZ). The FS were: a high grass allowance (HG FS), a high concentrate (HC FS) and a high stocking rate (HS FS). A separate farmlet existed for each FS and a total of 99, 117 and 117 animals were used in year 1, year 2 and year 3, respectively, divided equally between strains and FS. Individual animal intakes were estimated three times each year at pasture; in May (P1), in July (P2) and October (P3), corresponding on average to day 102, 177 and 240 of lactation, respectively. The HP cows achieved the highest milk yield, the NZ the lowest, while the HD was intermediate; the HP achieved the highest solid corrected milk yield with no difference between the NZ and HD strains. The grass DM intake of the HP strain was highest ( P<0·001) in all feeding systems. There was a significant strain×FS interaction for yield of milk, fat and protein, grass DM and total DM intake. The milk production response to the HC FS in P1 and P2 was significantly greater for both the HP and HD strains than for the NZ strain, while in P3 the response was highest for the HP, lowest for the NZ and intermediate for the HD. The reduction in pasture DM intake per kg of concentrate was greatest for the NZ strain, lowest for the HP and intermediate for the HD strain. The NZ strain also had the highest grass DM intake per kg live weight. The existence of strain×FS interactions for production and DM intake indicate that greater knowledge of both genotype and feeding environment is required to predict animal performance.

Two selection indexes, one intended for lamb producers and finishers and one for store lamb producers, were derived using genetic parameters for carcass and maternal characteristics from Conington et al. (2001) and economic values from Conington et al. (2004). This paper summarizes responses to selection for lamb traits only, after 5 years of selection (1998 to 2003) on two farms using these selection indexes. The index for lamb producers and finishers, evaluated on farm 1, with a flock size of 680 ewes, includes economic weightings for maternal traits as well as carcass weight, fat and conformation grades, whereas the index for store lamb producers, evaluated on farm 2, with a flock size of 580 ewes, only includes economic values for maternal traits and lamb growth to weaning. Three selection lines of Scottish Blackface sheep per farm were created with the first lambs born to each line in 1999. These lines were selection (S), control (C) and industry (I); they were of equal size on each farm. Five top- and five average-performing ram lambs were selected each year for the S and C lines respectively using a multi-trait best linear unbiased prediction (BLUP) implementation of the indexes. The I-line used four mature rams bought from industry, selected on appearance only, i.e. adherence to breed ‘type’. Results showed that 5 years after the implementation of the index, the S line had significantly higher index scores than the C or I lines on both farms. The means (s.d.) for the average index scores in 2003 are 114 (328), 119 (371) and 451 (328) (farm 1), and −8 (146), −11 (130), and 250 (129) (farm 2) for the C, I and S lines, respectively, giving predicted net differences (S-C) of £3·38 (farm 1) and £2·58 (farm 2) per ewe. Phenotypic responses showed significant S v. C differences in weaning weight on both farms. As predicted from previous analyses, no changes in carcass quality traits were seen at farm 1 although S-line carcass weights tended to be heavier than those from the C or I lines. The results show that genetic improvement using multi-trait selection indices has been successful and it is a viable, long-term strategy to improve levels of production for hill sheep in extensive environments.

The data sets consisted of field performance data from 54 848 purebred and 16 175 crossbred animals (Czech data set, CZ) and 16 610 purebred and 9 228 crossbred animals (Slovak data set, SK). Animals from the following breeds were included: Duroc, Hampshire, Piétrain, sire line of Large White (CZ) or Yorkshire (SK), Czech Meat pig (CZ) or Slovak Meat pig (SK), Belgian Landrace (SK). Two-trait animal models were calculated for average daily gain from birth to the end of the field test (ADG) and lean meat content (LM, only in CZ) or backfat thickness (BF, only in SK). The models included additive breed and breed heterotic effects. Piétrain was the breed with the highest LM and the lowest BF. The additive genetic breed effect was about 1·5% LM (CZ) in comparison with Large White or −0·4 mm BF (SK) in comparison to Yorkshire. The sire line of Large White (CZ) or the Yorkshire breed (SK) clearly exceeded all the remaining sire breeds in ADG (on average by 30 to 50 g/day). There was a clear tendency to negative heterosis in LM in all crossbred combinations (CZ). In BF, heterotic effects between −0·2 mm and +0·3 mm were estimated, mostly not being significant (SK). The estimates of the heterotic effects for ADG were positive throughout. Higher values up to 40 g/day (7%) were observed in the Czech data set. Though heterotic breed effects are of some importance especially for ADG, their inclusion in the equations for breeding value estimation will have only a minor impact on the predicted breeding values.

A model able to predict missing test day data for milk, fat and protein yields on the basis of few recorded tests was proposed, based on the partial least squares (PLS) regression technique, a multivariate method that is able to solve problems related to high collinearity among predictors. A data set of 1731 lactations of Sarda breed dairy Goats was split into two data sets, one for model estimation and the other for the evaluation of PLS prediction capability. Eight scenarios of simplified recording schemes for fat and protein yields were simulated. Correlations among predicted and observed test day yields were quite high (from 0·50 to 0·88 and from 0·53 to 0·96 for fat and protein yields, respectively, in the different scenarios). Results highlight great flexibility and accuracy of this multivariate technique.

Preference testing of two foods provides a means of assessing the relative value an animal places on the foods. Two experiments examined the relative choice of grass and maize silages by lactating dairy cows, and investigated whether protein supplementation, concentrate level or milk yield level of cow influenced this choice. In experiment 1, 16 cows including eight high (30 kg/day) and eight low (17 kg/day) yielding (milk level, ML) cows were offered a low (171 g/kg dry matter (DM)) or a high (300 g/kg DM) crude protein (CP) concentrate in eight 2×2 Latin squares. In experiment 2, four cows were offered a low (112 g/kg DM) or a high (334 g/kg DM) CP content of concentrate at a low (3·5 kg/day) or high (7 kg/day) concentrate level (CL) in a 4×4 Latin-square design.CP of concentrate did not influence the proportion of grass silage to maize silage eaten in either experiment. Also, neither ML of cows (experiment 1) nor CL (experiment 2) affected proportions of the two silages eaten. The mean proportions selected were 0·88:0·12 and 0·52:0·48 for grass and maize silages in experiments 1 and 2 respectively, which reflected differences between experiments in the digestibilities of the silages, and indicated that digestibility may be an important factor influencing the choice of silages.The CP, CL and ML treatments produced significant responses in silage and total DM intakes. Feeding behaviour studies showed the responses to CP were associated with differences in meal size, which is a function of duration of each meal and rate of intake. The number of meals taken per day was similar for all treatments and averaged 8·0 and 8·1 for experiments 1 and 2 respectively.It was concluded that whilst lactating cows modified their feeding behaviour in response to the diets available, there was no evidence they modified the proportions of the two silages selected in order to meet a target protein content in the total diet. It would appear therefore that other factors, of which digestibility may be important, have a higher priority in choice.

It is well established that plant oils reduce milk saturated fatty acid content and enhance concentrations of conjugated linoleic acid (CLA) and trans C18:1 in milk fat, but there is increasing evidence to suggest that milk fat CLA responses are often transient and decline over time. It is probable that time dependent adaptations in ruminal biohydrogenation and changes in milk fatty acid composition to lipid supplements are, at least in part, related to the composition of the basal diet. To test this hypothesis, 18 Holstein cows were used in a continuous randomized block design to examine changes in milk fatty acid composition over time in response to plant oils included in diets of variable composition. Cows were randomly allocated to one of three basal diets containing (g/kg dry matter (DM)) maize silage (267) and concentrates (733) (diet C); maize silage (332), grass hay (148) and concentrates (520) (diet M), or grass hay (642) and concentrates (358) (diet H). Basal rations were offered for 21 days, after which diets were supplemented with 50 g sunflower per kg DM (diets C-S and M-S) or 50 g linseed oil per kg DM (diet H-L). Oils were included in all rations incrementally over a five day period (days 0–4), and responses to 50 g/kg DM of the respective oils were evaluated for 17 days (days 4 to 20). Milk fatty acid composition was intensively monitored from days −2 to 20. In contrast to the H-L diet, both C-S and M-S treatments decreased (P<0·05) DM intake, milk fat content and yield, while the C-S diet also reduced (P<0·05) milk yield. Milk fat cis-9, trans-11 CLA and trans-11 C18:1 contents were enhanced on the C-S and M-S treatments but the increases were transient reaching the highest concentrations between days 4 and 6 (cis-9, trans-11 CLA: 1·94 and 2·18 g per 100 g total fatty acids; trans-11 C18:1: 4·88 and 6·23 g per 100 g total fatty acids, respectively) but declined thereafter. In marked contrast, concentrations of cis-9, trans-11 CLA and trans-11 C18:1 in milk from the H-L diet increased gradually over time, responses that were maintained until the end of the experiment (2·89 and 7·49 g per 100 g total fatty acids, respectively).Decreases in milk fat cis-9, trans-11 CLA and trans-11 C18:1 after day 6 on the M-S and C-S diets were associated with concomitant increases in milk fat trans-10 C18:1 content reaching 7·22 and 18·62 g per 100 g total fatty acids on day 18, respectively, whereas concentrations of trans-10 C18:1 in milk on the H-L diet remained low throughout the experiment (0·70 g per 100 g total fatty acids on day 18). Furthermore, milk fat trans-11, cis-13 CLA, trans-11, trans-13 CLA and trans-12, trans-14 CLA contents were all enhanced on the H-L diet, while the M-S and C-S diets increased trans-8, cis-10 CLA, trans-10, cis-12 CLA and trans-9, cis-11 CLA concentrations. Across all diets, decreases in milk fat content were associated with increases in milk trans-10 C18:1, trans-10, cis-12 and trans-9, cis-11 CLA concentrations (r2=0·93, 0·88 and 0·89, respectively). In conclusion, the relative abundance of trans C18:1 and CLA isomers in milk fat were dependent on the composition of the basal diet, type of plant oil and duration of lipid supplementation, highlighting the challenges in developing nutritional strategies for the production of milk highly enriched with CLA over an extended period of time.

The aims of this work were first to evaluate nutritional requirements of early weaned kits (23 days of age), more especially fibre (experiment 1) and protein (experiment 2) needs. In experiment 1, 276 early weaned rabbits were offered from 23 to 50 days of age one of the three experimental diets containing increasing acid-detergent fibre level (160, 190 or 220 g/kg). Fibre was substituted by starch and fat to obtain three isoenergetic diets. In experiment 2, 306 early weaned rabbits were offered from 23 to 50 days of age one of the three experimental diets containing increasing crude protein (CP) level (150, 180 or 210 g/kg). Protein was substituted by starch and fat to obtain three isoenergetic diets. These studies revealed no effect of the dietary fibre level and the dietary CP level on health status. But from 23 to 36 days of age rabbits given diets containing a fibre level over 190 g/kg or a CP level under 180 g/kg showed the lowest growth rate as compared with other respective treatments. Secondly, this research aimed to evaluate the interaction between age at weaning (23 days or 35 days of age) and food (RD and RY diets) on digestive health and performances of young rabbits (experiment 3). RD diet was formulated to contain (per kg) 170 g starch, 160 g fibre and 180 g CP (according to the nutritional requirements of does) and RY diet was formulated to reach 110 g starch, 160 g fibre and 210 g CP (according to the results of experiments 1 and 2). 39 litters of nine pups per litter were assigned at 18 days of age to one of four experimental groups in a 2×2 factorial design: RD23 (no.=84 rabbits), RY23 (no. =85 rabbits), RD35 (no. =86 rabbits) and RY35 (no. =74 rabbits). Food intake and live weight were not influenced by feeding strategy. Between 23 and 35 days of age, mortality was higher in RY than in RD group (20·4 v. 6·8% respectively; P<0·05). During this period growth rate was proportionately 0·584 higher in conventionally weaned than in early weaned rabbits ( P<0·001). After 35 days of age, food intake and growth rate were proportionately 0·104 and 0·097 higher respectively in conventionally than in early weaned rabbits ( P<0·05). Consequently, live weight was higher in conventionally weaned rabbits at both 35 and 53 days of age (proportionately +0·113 and +0·267 respectively; P<0·001). Mortality rate between 23 and 35 days was 21 points higher ( P<0·001) in early weaned than in conventionally weaned pups and 43 points higher ( P<0·001) from 35 to 53 days of age. These data suggest that the removal of milk feeding by early weaning leads to detrimental effects on health and growth of the young, which were not compensated by a diet meeting better their nutritional needs.

An experiment was conducted to evaluate the effects of dietary supplementation of a polysaccharide isolated from Astragalus membranaceus (APS) on performance and immune responses in weaned pigs. A total of 144 crossbred pigs weaned at 26 to 30 days of age with an average initial live weight (LW) of 7·64 (s.d. 0·290) kg were randomly allotted to six diets supplemented with APS at 0, 100, 250, 500, 750, and 1000 mg/kg. There were six replicates (three barrow pens and three gilt pens) per diet treatment with four pigs per pen. Pigs were given food ad libitum for 21 days and the LW and food intake were measured on days 14 and 21. Pigs were intramuscularly injected with 1 mg/kg LW ovalbumin (OVA) on day 14 to evaluate humoral immune response. Blood samples were collected on day 21 to measure leukocyte differential counts, percentage of blood CD4+ and CD8+ lymphocyte subsets, lymphocyte proliferation response to Concanavalin A, serum concentration of immunoglobulin G (Ig G), interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-10 (IL-10), interferon-γ (IFN-γ) and specific OVA antibody. The results showed that the average daily gain, the numbers of WBC and lymphocytes, the proportion of CD4+ lymphocyte subset, and the contents of IL-2 and IFN-γ increased ( P < 0·05) as pigs were fed increased supplemental level of APS during the 21 d period. However, the contents of specific OVA antibody, Ig G, IL-4, and IL-10 were not affected ( P > 0·05) by dietary levels of APS. The broken line analysis and quadratic regression analysis indicate that the optimal APS supplemental level would be between 381 mg/kg and 568 mg/kg for the maximal ADG and from 324 to 563 mg/kg for immune responses. Collectively, this study suggests that dietary APS can be used as a potential immuno-modulating agent by affecting cellular immunity of weaned pigs.

There is a growing body of evidence to suggest direct involvement of the cytokines interleukin-1 (IL-1), interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) in the initiation of skeletal muscle catabolism and depressions in growth performance as a result of diseases, while TNF-α and IL-6 are presumably under the control of IL-1. An experiment was conducted to investigate whether an interleukin-1 receptor antagonist (IL-1ra) could reduce growth depressions in a model of subclinical disease in growing pigs. In this study, 24 crossbred barrows and gilts were randomly assigned to three treatments: (1) healthy control (HC), saline infusion; (2) sick control (SC), infection with Mycoplasma hyopneumoniae and vaccination with porcine reproductive and respiratory syndrome modified live virus (PRRSV) vaccine and saline infusion; (3) SC plus infusion with IL-1ra (SC+IL-1ra). An additional six pigs were killed at the initiation of the trial to determine initial body composition for estimation of carcass nutrient retention rates. During the 28-day experimental period, the SC pigs had growth performance similar to that of the HC pigs and the highest levels of plasma cytokines (P<0·10). The SC+IL-1ra pigs had growth performance similar to the HC pigs, but the SC+Il-1ra pigs tended to have higher growth rates than the SC pigs (P<0·10), the highest carcass protein accretion rate (P<0·10) and similar levels of plasma cytokines compared with the HC pigs. Plasma levels of insulin-like growth factor-1 (IGF-1) on day 22 tended to be higher (P<0·10) in the HC pigs compared with the SC or SC+IL-1ra pigs and treatment×sex interaction was observed on day 29; the IGF-1 levels tended to be higher in SC+IL-1ra gilts and SC barrows (P<0·10). These results indicate that infusion with IL-1ra in a model of subclinical disease helps attenuate the catabolic effects of immune system stimulation.

The stromovascular fraction of adipose tissue from sheep, like that of other species, contains preadipocytes which can be induced to differentiate in culture, providing a potentially useful system for studying adipocyte development. Differentiation of ruminant preadipocytes has only been partly characterized previously so we have investigated the factors regulating the development of lipogenesis and lipolysis in sheep cells. Insulin, rosiglitazone (a peroxisome proliferation activated receptor-γ agonist) and either dexamethasone or a lipid suplement are required during differentiation for maximum rates of lipogenesis, whereas all four components are required to achieve maximum rates of catecholamine-stimulated lipolysis. Tri-iodothyronine had no effect on the development of lipogenesis but resulted in a reduced rate of catecholamine-stimulated lipolysis. Lipogenesis and lipolysis also differed in that the rate of lipogenesis increased to a maximum at about 10 days of differentiation and then fell, whereas the rate of lipolysis reached a plateau at about 10 days. By contrast to catecholamine-stimulated lipolysis, there is little or no evidence for development of the adenosine-based antilipolytic system; this may be because response to adenosine develops very late during preadipocyte differentiation or additional, unidentified factors are required to induce this antilipolytic system. Lipogenesis in differentiated preadipocytes responded to both insulin and growth hormone. These studies show that the development of lipogenesis and lipolysis are under distinct control systems. Furthermore, while preadipocytes differentiated in vitro show many of the characteristics of adipocytes differentiated in vivo, there are still significant differences.

The objective of this study was to establish the pro-inflammatory cytokine and acute phase protein responses to low-dose lipopolysaccharide (LPS) challenge in pigs and to determine whether these immune parameters could also be measured in saliva. Possible gender differences in the acute phase reaction were also assessed. At 6 weeks of age, 24 male and 24 female pigs were injected intraperitoneally with a single dose of 0 or 5 μg/kg live weight (LW) of LPS from Escherichia coli (treatment). Matched saliva and blood samples were taken at 0, 2, 4, 8, 12 or 24 h after treatment administration. Samples were analysed for concentrations of the pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α) and interleukin-1beta (IL-1β), the acute phase proteins C-reactive protein (CRP), serum amyloid A (SAA), haptoglobin (Hp), and cortisol. Low-dose LPS administration increased plasma levels of TNF-α (P<0·001), CRP (P<0·05) and SAA (P<0·05) but did not affect plasma concentrations of IL-1β or Hp (P>0·1). Treatment by time interactions showed that plasma levels of TNF-α and CRP in LPS-treated pigs peaked at 2 h (P<0·001) and 12 h (P<0·01), respectively. Low-dose LPS injection tended to increase plasma concentrations of cortisol (P=0·056) and the response to LPS differed between genders (P<0·05), with females showing higher cortisol responsiveness to the challenge (P<0·01). Males showed higher levels of both cytokines regardless of the treatment (P<0·05), probably due to the inhibition of cytokine synthesis by cortisol. Concentrations of both pro-inflammatory cytokines were consistently detectable in saliva and were present in higher concentrations than in plasma (P<0·001). Hence, plasma TNF-α, CRP and SAA are useful indicators of sub-acute inflammation/infection in pigs as simulated by a low-dose LPS challenge and gender differences exist in the pro-inflammatory cytokine response after a low dose of LPS.

Insulin-like growth factor-1 (IGF-1) is a polypeptide that regulate growth, differentiation and muscle regeneration in several species. This study was designed to analyse the cDNA sequence of IGF-1 in giant panda, its gene expression and tissue distributions in relation to growth, development and reproduction of captive giant pandas. A cDNA encoding IGF-1 was cloned by reverse transcriptase-PCR from a male giant panda cub liver tissue. Sequence alignment analysis showed the cysteine residues and other amino acid residues of the mature IGF-1 peptide of giant panda are highly conserved in mammalian species. DNA encoding the mature IGF-1 peptide of the giant panda was ligated with pET-DsbA expression vector and expressed in E. coli BL21. Western blot confirmed the IGF-1 antigen activity of the recombinant protein. By in situ hybridization and immunohistochemistry analysis it is demonstrated that the IGF-1 mRNA distribution abundance were significantly higher in the liver, muscles and heart than those in the other tissues studied. However, the IGF-1 peptide distribution abundances in all the tissues studied did not show any significant differences. The localization of the IGF-1 peptide was in accordance with that of mRNA for each tissue. These results may suggest that IGF-1 play an autocrine or paracrine rôle in regulation of the giant panda growth and development.

This study investigates the accuracy of an automatic image analysis method that was developed for spiral computed tomography scans (SCTS), with the objective of calculating the volume of muscle in the hind leg (HLMVCT) and lumbar region (LRMVCT) in lambs. The first step in the image analysis method was the isolation (segmentation) of the muscle regions in each image of the SCTS, using a new program that was implemented in the Sheep Tomogram Analysis Routines software (STAR). Due to the differences of muscle shape in the regions investigated, the new segmentation program applies different segmentation paths in specific subregions. These were automatically identified by the program based on skeletal landmarks. After the segmentation was completed, the muscles areas were automatically measured by counting the pixels representing muscle in each image; the volumes were calculated by adding the muscle areas of each image multiplied by the depth of the image (inter-slice distance). The accuracy of these measures of muscle volume was evaluated, using regression analysis, by comparing HLMVCT and LRMVCT to the hind leg and lumbar region muscle weights measured after dissection (HLMWD, no. =240, and LRMWD, no. =50, respectively) of Texel (TEX) and Scottish Blackface (SBF) female and male lambs slaughtered in 2003-04. The effects of breed, sex and year on the association (SCTS v. dissection) were evaluated. There was a strong association between HLMVCT and HLMWD ( R2=97·4%), which only increased slightly ( R2=97·7%) when breed was included in the model. This indicates that HLMWD can be estimated directly from HLMVCT with a high degree of accuracy. For the lumbar region, the association was high ( R2=83·0% to 88·8% depending on the model) but lower than in the hind leg, probably because the automatic segmentation isolates only the areas of the longissimus lumborum and multifidi muscles. Breed had a significant effect on the prediction of LRMWD from LRMVCT, as well as sex in the case of the TEX lambs. The results indicated that the predictions of LRMWD from LRMVCT require different equations for very divergent breeds such as TEX and SBF.

Milk production and reproductive performance of pluriparous dairy cows was compared for cows whose lactations were induced by hormonal treatment or followed natural calving. The study was conducted on 179 high-yielding dairy cows in a large dairy operation in a hot arid environment of northern Mexico, where bovine somatotropin (bST) was routinely used in all cows. To induce lactation, 98 cows that had previously failed to become pregnant were treated with 500 mg bST on days 1, 8 and 21. From days 2 to 8, cows were treated with oestradiol cypionate (0·30 mg/kg live weight (LW) per day) and progesterone (0·28 mg/kg LW per day). From days 9 to 15, oestradiol cypionate alone was given. PGF2α was given on day 16. Nothing was administered on days 17 and 18, and 15 mg flumetasone was administered from days 19 to 21. Lactation was induced successfully in all 98 cows subjected to the hormone treatment. All cows received 500 mg bST every 14 days throughout lactation from 63±7 days after lactation had started. Cows with induced lactations produced less (P<0·01) milk per 305-day lactation (9599±1387 kg) than controls (12 302±1245 kg). Proportion of cows pregnant was similar in induced cows and non-treated cows (71 v. 75%). Induction of lactation was associated with increased numbers of services per pregnancy (5·8±4·0 v. 4·22±2·98; P<0·01) compared with controls; however, impaired reproduction might not necessarily have been related to the hormonal treatment to induce lactation, but due to the nature of the cows utilized for this treatment group. This protocol can be used on dairy farms where bST treatment and prolonged steroid administration of dairy cows is legally permitted.

In France, beef bulls are finished by breeder-finishers who produce calves and then fatten them, or by specialized finishers who fatten bulls that they buy. According to previous results on both dairy cows and pigs, breeding on the farm promotes positive attitudes of farmers towards animals, which can lead to improved animal health and growth. The mixing of bulls on their arrival at a specialized unit could stress them and thus impair health and growth. We hypothesized that breeder-finishers have more positive attitudes towards bulls and their work with bulls than specialized finishers, and that positive attitudes lead to better production, whereas mixing may be counterproductive. We observed 1038 bulls (67 groups) finished by breeder-finishers or specialized finishers in mixed and unmixed groups. Using a questionnaire, we assessed farmers' beliefs about the sensitivities of bulls, their attitude towards contacts with bulls, their beliefs about successful factors in finishing, and job satisfaction. We recorded the number of clinical signs and weight gain of the bulls. Specialized finishers tended to have more negative contacts with bulls than breeder-finishers ( P=0·06). Poor health of bulls was associated with (i) a positive attitude towards gentle contacts with bulls ( P<0·01), (ii) job satisfaction ( P=0·01), and (iii) was negatively correlated to beliefs in bulls being difficult animals ( P=0·09). Fast growth of bulls was associated with job satisfaction ( P<0·01). Unmixed bulls grew faster than mixed bulls ( P=0·05). We conclude that in finishing bulls, it is production results that have an impact on attitudes, rather than the opposite: the need for close contacts with bulls resulting from health problems engenders more positive attitudes of farmers towards their animals, and good production results increase job satisfaction. Variations in production results between breeder-finishers and specialized finishers seem to lie more in the fact that the latter always use animals mixed at the beginning of the finishing period - with mixing impairing growth - than in the attitudes of farmers towards animals and their work.

Although the farrowing process has an impact on postnatal piglet survivability and growth performance, information on factors that influence the farrowing process under field conditions is rare. The objective of the study was to determine factors influencing the duration of farrowing and birth intervals in Large White×Landrace crossbred sows. Data were collected from the Pig Industry Board, Acturus, Zimbabwe. The durations of farrowing were log transformed to normalize them, while birth intervals remained skewed after the transformation. As a result, Friedman's test was used to analyse for factors affecting birth intervals. The mean duration of farrowing was 217 min. Number of piglets born alive (NBA), average birth weight and the presence or absence of stillbirths influenced ( P<0·05) the duration of farrowing. The total number of piglets born (NBT) and order of piglets significantly influenced birth intervals ( P<0·05). There was wide variation in birth intervals, with the within-litter coefficient of variation ranging from 50 to 140 percent. The relationship between birth interval and order of birth was: Y=0·1011x2−1·771x+37·917 ( P<0·05). Relative birth order, expressed as a proportion of the total number of piglets born, also showed a significant quadratic relationship with birth interval: Y=0·0021x2−0·121x+23·952 ( P<0·05). The study found that relative birth order, NBA and NBT play an important rôle in influencing birth intervals and duration of farrowing, while parity and piglet weight do not. Logarithmic transformation failed to normalise data on birth intervals, highlighting their highly skewed nature.

Sensor feeding is a liquid feeding system for fattening pigs that is operated with a restricted animal/feeding-place ratio (AFR). The aim of the present study was to quantify the effect of three different AFRs (4:1, 7:1 and 13:1, calculated with a feeding space of 33 cm per animal) on the performance and behaviour of fattening pigs (mean initial weight 26·3 (s.d. 3·3) kg, live weight at slaughter 102 (s.d. 5) kg). The pigs were housed in groups of 40 and each AFR was tested with seven groups (21 groups in total). The daily weight gain of the individual pigs was calculated from the beginning of the experiments until slaughter. Additionally, the lean meat percentage was recorded (AutoFOM). Feeding behaviour was observed by means of 24-h video recording at the ages of 14 and 17 weeks with scan sampling every 5 min. The daily weight gain decreased with increasing AFR ( P<0·01) and females had lower weight gains than barrows ( P<0·001). The lean meat proportion was influenced by the AFR ( P<0·01) and sex of the pigs ( P<0·001). Proportions were highest with the AFR 13:1 and in females. The average number of pigs feeding simultaneously was highest for the AFR of 4:1 ( P<0·01). Moreover, the ingestion rate per day (kg/min) increased with increasing AFR ( P<0·05). The average number of pigs waiting behind other pigs feeding at the trough was highest with the AFR 13:1 ( P<0·001).In conclusion, growth performance and pig behaviour were negatively affected by an AFR of 13:1, which cannot be recommended for use with this feeding system. With an AFR of 4:1 lean meat values were low.