The objective of this study was to investigate the effect of infrared (IR) temperature on thermoregulatory behaviour in suckling piglets in the first 3 weeks after farrowing. A total of 10 piglets from each of the 16 litters were exposed to recommended IR temperature conditions at 1, 2 and 3 weeks of age, with a mild offset (4°C) in IR temperature during the first experiment and a more challenging offset (8°C) during the second experiment. Digital photos were taken when all piglets had settled in the creep area, and the lying posture and huddling behaviour were analysed. A lying posture score and a huddling score was calculated by multiplying the number of piglets in each category with a given value for each category, based on different lying postures and different degrees of huddling behaviour. With a 4°C change in IR temperature, the piglets tended to alter their lying posture, while an 8°C change had a significant effect on lying posture (P < 0.01). A change in IR temperature of 4°C had no effect on the degree of huddling. The huddling score decreased significantly with 8°C change in IR temperature (P < 0.05). Postural changes, rather than changes in degree of huddling were the preferred thermoregulatory strategy for suckling piglets.

It is known that the level of dietary protein modulates the enzymatic activity of the digestive tract of fish; however, its effect at the molecular level on these enzymes and the hormones regulating appetite has not been well characterised. The objective of this study was to evaluate the effect of CP on the activity of proteases and the expression of genes related to the ingestion and protein digestion of juveniles of red tilapia (Oreochromis sp.), as well as the effects on performance, protein retention and body composition of tilapia. A total of 240 juveniles (29.32 ± 5.19 g) were used, distributed across 20 tanks of 100 l in a closed recirculation system. The fish were fed to apparent satiety for 42 days using four isoenergetic diets with different CP levels (24%, 30%, 36% and 42%). The results indicate that fish fed the 30% CP diet exhibited a higher growth performance compared to those on the 42% CP diet (P < 0.05). Feed intake in fish fed 24% and 30% CP diets was significantly higher than that in fish fed 36% and 42% CP diets (P < 0.05). A significant elevation of protein retention was observed in fish fed with 24% and 30% CP diets. Fish fed with 24% CP exhibited a significant increase in lipid deposition in the whole body. The diet with 42% CP was associated with the highest expression of pepsinogen and the lowest activity of acid protease (P < 0.05). The expression of hepatopancreatic trypsinogen increased as CP levels in the diet increased (P < 0.05) up to 36%, whereas trypsin activity showed a significant reduction with 42% CP (P < 0.05). The diet with 42% CP was associated with the lowest intestinal chymotrypsinogen expression and the lowest chymotrypsin activity (P < 0.05). α-amylase expression decreased with increasing (P < 0.05) CP levels up to 36%. No significant differences were observed in the expression of procarboxypeptidase, lipase or leptin among all the groups (P > 0.05). In addition, the diet with 42% CP resulted in a decrease (P < 0.05) in the expression of ghrelin and insulin and an increase (P < 0.05) in the expression of cholecystokinin and peptide yy. It is concluded that variation in dietary protein promoted changes in the metabolism of the red tilapia, which was reflected in proteolytic activity and expression of digestion and appetite-regulating genes.

Two in vitro experiments were carried out to quantify the incorporation of nitrogen (N) by pig colonic bacteria during the fermentation of dietary fibre, including non-starch polysaccharides and resistant starch. In the first experiment, five purified carbohydrates were used: starch (S), cellulose (C), inulin (I), pectin (P) and xylan (X). In the second experiment, three pepsin–pancreatin hydrolysed ingredients were investigated: potato, sugar-beet pulp and wheat bran. The substrates were incubated in an inoculum, prepared from fresh faeces of sows and a buffer solution providing 15N-labelled NH4Cl. Gas production was monitored. Bacterial N incorporation (BNI) was estimated by measuring the incorporation of 15N in the solid residue at half-time to asymptotic gas production (T/2). The remaining substrate was analysed for sugar content. Short-chain fatty acids (SCFA) were determined in the liquid phase. In the first experiment, the fermentation kinetics differed between the substrates. P, S and I showed higher rates of degradation (P < 0.001), while X and C showed a longer lag time and T/2. The sugar disappearance reached 0.91, 0.90, 0.81, 0.56 and 0.46, respectively, for P, I, S, C and X. Among them, S and I fixed more N per gram substrate (P < 0.05) than C, X and P (22.9 and 23.2 mg fixed N per gram fermented substrate v. 11.3, 12.3 and 9.8, respectively). Production of SCFA was the highest for the substrates with low N fixation: 562 and 565 mg/g fermented substrate for X and C v. 290 to 451 for P, I and S (P < 0.01). In the second experiment, potato and sugar-beet pulp fermented more rapidly than wheat bran (P < 0.001). Substrate disappearance at T/2 varied from 0.17 to 0.50. BNI were 18.3, 17.0 and 10.2 fixed N per gram fermented substrate, for sugar-beet pulp, potato and wheat bran, respectively, but were not statistically different. SCFA productions were the highest with wheat bran (913 mg/g fermented substrate) followed by sugar-beet pulp (641) and potato (556) (P < 0.05). The differences in N uptake by intestinal bacteria are linked to the partitioning of the substrate energy content between bacterial growth and SCFA production. This partitioning varies according to the rate of fermentation and the chemical composition of the substrate, as shown by the regression equation linking BNI to T/2 and SCFA (r2 = 0.91, P < 0.01) and the correlation between BNI and insoluble dietary fibre (r = −0.77, P < 0.05) when pectin was discarded from the database.

The performance of 200 F1 Friesian ♂ × zebu ♀ and 90 zebu heifers on 14 dairy cooperative farms near Addis Ababa was compared over a 2-year period. The farms varied in management and feeding but in general the standards were low. Each farm had zebu and Friesian × zebu cows given the same management and feeding. Measurements were made of milk production traits of economic importance, including physiological and behavioural factors important for management purposes.

The Friesian ♂ × zebu ♀ crossbred heifers showed an advantage in having an earlier age at puberty and at first calving, higher milk production, longer lactations, better disposition at milking and better reproductive performance. The calves from these crossbred heifers were larger at birth but there were more problems at calving. The zebu heifers withstood better the two periods of drought that occurred during the study. No significant differences were found in disease incidence, parasitic resistance, mastitis incidence or mortality. The interval between oestrus was normal in the F1 heifers but longer in the zebus. The duration of gestation was much longer in the zebus (mean 291 days). The duration of oestrus was 4·5 h for the zebu and 10·0 h for the F1 heifers, the latter being-much longer than the mean of 7·4 h reported in the literature. The F1 heifers showed the first oestrus after calving much sooner than did the zebus.

Intramuscular connective tissue (IMCT) is mainly composed of several fibrils (known as total collagen (TCol)) linked between each other by different chemical cross-links (CLs), the whole being embedded in a matrix of proteoglycans (PGs). In the field of beef quality, there is limited information on the role of CLs and PGs. Accordingly, several authors suggest that, to investigate the role of IMCT, it is important to investigate them just like TCol and insoluble collagen (ICol). In muscle, there are two other components, the muscle fibres and intramuscular fat (IMF) content. There are limited data on the relationships between these three components of muscle and then on possibility to independently manipulate these characteristics in order to control the final quality of meat. The present study aimed to investigate whether consistent relationships exist between these different components of muscle. Therefore, the present study compared four muscles of two cattle types (dairy and beef) to determine associations between TCol, ICol, CLs and PGs. Data were analysed across and within muscle (M) and animal type (AT) based on residuals. There was a strong M and AT effect for all muscle characteristics and an interaction M × AT for type I muscle fibres and IMF. Correlations between TCol, ICol and their CLs were M- and AT-independent. Total proteoglycans were positively correlated with TCol and ICol in a muscle-dependent manner irrespective of AT, but no correlation was found with CLs. On the contrary, CLs were negatively correlated with the ratio TPGs : TCol in an M-dependent manner, irrespective of AT. TCol, ICol and CLs were positively and negatively correlated with type IIA and IIB+X muscle fibres only in longissimus thoracis (LT) muscle, regardless the AT. Insoluble collagen was the only parameter of IMCT to be correlated with type I muscle fibres but only in LT muscle, irrespective of AT. There was no correlation between PGs and muscle fibre types, but PGs were the only IMCT component to be related with IMF in an M-dependent manner, irrespective of AT. Finally, there was no correlation between muscle fibre types and IMF content within M and AT. This study revealed that there is a strong relationship between IMCT components irrespective of M, an M-dependent relationship between the IMCT components and muscle fibre types and few (only with PGs) or no relationship between IMF and IMCT and muscle fibres.

The aim of this study was to compare the short-term post-weaning behaviour of piglets treated either neutrally or aversively during the suckling period. A total of 24 lactating sows and their litters were housed in different rooms according to treatment. A female experimenter (P1) was in charge of feeding and cleaning from days 10 to 27 after birth. For the aversive treatment (Aver), P1 was noisy, moved harshly and unpredictably and shouted frequently during routine cleaning of facilities and animal handling. For the neutral treatment (Neut), P1 used a soft tone of voice and was careful during the same routine. At weaning, the avoidance response of piglets to an approaching experimenter in a novel place was assessed in four piglets from each litter. Scores ranged from 1 (experimenter could touch piglet) to 4 (piglet escaped as soon as person moved). The test was repeated twice, with a 1-h interval, with P1, who wore blue trousers and white T-shirt, and a second handler unfamiliar to the piglets (P2, who wore blue coveralls). Thereafter, litters from the same treatment were mixed and housed in separate rooms, balanced for gender and live weight (n = 12 groups of 4 piglets/treatment). Behaviour time budgets were registered by scan sampling every 2-min, for 4 h per day, for 4 days. Piglets were weighed at birth, at weaning and on day 5. Effects of treatment and handler on responses to the avoidance test were analysed with non-parametric tests and effects of treatment with a mixed model for repeated measures. Avoidance score was higher for Aver than Neut piglets when tested with P1 (P = 0.04) but not with P2 (P = 0.8). When piglets’ responses to the different handlers were compared within each treatment, no significant differences were found. Frequencies of resting were lower (P < 0.001), whereas escape attempts (P < 0.03), agonistic interactions (P < 0.02) and frequency of presence at feeder (P < 0.001) were higher in the Aver than in the Neut groups. Feed and water intake and weight gain did not differ between treatments. We conclude that 4-week-old piglets can discriminate a handler according to the nature of treatment received during suckling. In addition, piglets treated aversively seem to have more difficulty adapting to weaning than those treated neutrally during the suckling period.

This study examined the effects of glutamine and nucleotides on growth, intestinal villous height and immune responses of weaned pigs. Eighty weaned pigs (Landrace ✕ Yorkshire ✕ Duroc) were randomly assigned to five treatments, including a control diet and a 2 (glutamine 1·0 and 1·5%) by 2 (nucleotides 500 and 1000 p.p.m.) factorial design. There were no differences among the five treatments in weight gain from weeks 0 to 4 and 0 to 8 of the experiment. However, the food intake of treatment 3 (glutamine 1·0% and nucleotides 1000 p. p. m. ) for weeks 4 to 8 was higher (P < 0·05) than that of the control group. Intestinal villous height, and serum immunoglobulin-G concentration 2 h post lipopolysaccharide injection, were higher (P < 0·05) for pigs administered treatment 3 than for controls. Furthermore, foot and mouth disease (FMD) neutralizing antibody titres were also higher (P < 0·05) than the control group for pigs given treatment 3 when measured 3 weeks following vaccination with FMD antigen. These observations suggest that a combination of 10% of glutamine and 1000 p. p. m. of nucleotides in the diet could improve food intake and intestinal villous height and promote the immune responses and FMD antibody titres of weaned pigs.

1. The experiment was designed to compare the protein and energy metabolism of pigs growing at 25°c or 34°C. The pigs were given two levels of feeding while growing between 25 and 75 kg live weight.

2. The high temperature was associated with increases in rectal temperature of 1·2 to 20°C. Both pigs on the higher level of feeding at 34°C became lame in their hind legs.

3. The high temperature was also associated with increases in heat production and in urinary nitrogen and energy losses for pigs fed at the higher level of feeding only; however fasting heat production was not affected significantly by temperature. The high temperature had no effect on the apparent digestibility of the diet.

4. It was calculated from data for pigs at both levels of feeding kept at 25°C, that efficiency of utilization of metabolizable energy (ME) above maintenance was 71%, and the maintenance requirement for ME was 100 kcal/kg0·75 day. Energy retention was reduced at 34°C in pigs fed on the higher level of feeding.

The objective of this study was to investigate the tissue-specific mRNA expression of different cytochrome P450 (CYP) isoforms, UDP glucuronsyl transferase 1A1 (UGT1A1) and glutathione-S-transferase (GSTA1) in the different tissues (liver, mammary gland, lungs, spleen, kidney cortex, heart, masseter muscle and tongue) of cattle, using quantitative real-time polymerase chain reaction (qPCR). CYP1A1-like mRNA was expressed in all of the tissues examined, including the liver, with the highest expression level in the kidney. CYP1A2-, 2E1- and 3A4-like mRNAs were only expressed hepatically. Interestingly, significant expression of CYP2B6-like mRNA was recorded in the lung tissue, while CYP2C9-like mRNA was expressed in the liver and kidney tissues of the cattle examined. UGT1A1- and GSTA1-like mRNAs were expressed in all of the examined tissues, except the mammary glands, and the highest expression levels were recorded in the kidney. The high expression of UGT1A1 in the lung tissue and GSTA1 in the liver tissue was unique to cattle; this has not been reported for rats or mice. The findings of this study strongly suggest that the liver, kidneys and lungs of cattle are the major organs contributing to xenobiotics metabolism.

The objective of this study was to assess the growth and development of carcass composition of entire male and female lambs of three British hill breeds (Scottish Blackface, Welsh Mountain, and Shetland), from weaning to approaching maturity, when kept under conditions designed to be nutritionally non-limiting. Lambs were weaned at 8 weeks of age and given a high-quality pelleted diet ad libitum until slaughter at one offive different degrees of maturity. The Gompertz growth function was used to characterize, for each genotype, the growth curve and to provide estimates of mature weight. As expected, there were significant effects of breed and sex on both food intake and growth rate. Growth rate was depressed, relative to the Gompertz fit, during the months of October to January, and intake was similarly depressed. The estimates of mature weight for the females of each breed were: Scottish Blackface, 69; Welsh Mountain, 61; Shetland, 46 kg. The mature weights of the males were found to be not significantly different from 1-3 times the mature weight offemales. Relationships between carcass composition and live weight were derived by allometric regression. This study provides the first full description of the growth and meat production potential of the three breeds.

From birth to slaughter, pigs are in constant interaction with microorganisms. Exposure of the skin, gastrointestinal and respiratory tracts, and other systems allows microorganisms to affect the developmental trajectory and function of porcine physiology as well as impact behavior. These routes of communication are bi-directional, allowing the swine host to likewise influence microbial survival, function and community composition. Microbial endocrinology is the study of the bi-directional dialogue between host and microbe. Indeed, the landmark discovery of host neuroendocrine systems as hubs of host–microbe communication revealed neurochemicals act as an inter-kingdom evolutionary-based language between microorganism and host. Several such neurochemicals are stress catecholamines, which have been shown to drastically increase host susceptibility to infection and augment virulence of important swine pathogens, including Clostridium perfringens. Catecholamines, the production of which increase in response to stress, reach the epithelium of multiple tissues, including the gastrointestinal tract and lung, where they initiate diverse responses by members of the microbiome as well as transient microorganisms, including pathogens and opportunistic pathogens. Multiple laboratories have confirmed the evolutionary role of microbial endocrinology in infectious disease pathogenesis extending from animals to even plants. More recent investigations have now shown that microbial endocrinology also plays a role in animal behavior through the microbiota–gut–brain axis. As stress and disease are ever-present, intersecting concerns during each stage of swine production, novel strategies utilizing a microbial endocrinology-based approach will likely prove invaluable to the swine industry.

The objective was to study the effect of type of concentrate with varying starch and fibre content on growth and gastrointestinal development in preweaned dairy calves. Thirty-two newborn Danish Holstein male calves were allocated to four treatment groups in eight blocks of four calves. An experimental low-starch, high-molasses, high-fibre (EXP) concentrate or a traditional high-starch (TRA) concentrate were fed either at a high (HIGH; 2 × 3.2 kg/day) or a low (LOW; 2 × 1.6 kg/day) whole milk allowance in a 2 × 2 factorial design. TRA contained 350 and EXP 107 g starch/kg dry matter (DM), whereas the NDF content was 136 and 296 g/kg DM, respectively. Metabolizable energy (ME) was 11.2 and 12.2 MJ ME/kg DM in EXP and TRA, respectively. All calves had free access to artificially dried grass hay (9.8 MJ ME/kg DM). Four calves were culled during the experiment. The calves were euthanized either at 38 (12 calves) or 56 days (16 calves) of age. Evaluated across both slaughter ages, there was no difference between TRA and EXP in concentrate and hay intake, rumen weight and papillation. EXP resulted in increased villi number in duodenum and jejunum compared with TRA. Concentrate intake and reticulo-rumen weight was higher for LOW compared with HIGH milk allowance, whereas live weight gain was 20% lower. The results show that a low-starch, high-molasses, high-fibre concentrate with 8% lower ME content tended to reduce daily gain compared with a traditional calf starter concentrate, but resulted in similar ruminal development in preweaned calves both on a high and a low milk allowance fed along with grass hay. Furthermore, the results suggest that the experimental concentrate stimulated intestinal villi growth over that of the traditional concentrate.

This study aimed to assess the effect of the number of straw bales (SBs) provided on the behaviour and leg health of commercial broiler chickens. Houses containing ~23 000 broiler chickens were assigned to one of two treatments: (1) access to 30 SBs per house, ‘30SB’ or (2) access to 45 SB per house, ‘45SB’. This equated to bale densities of 1 bale/44 m2 and 1 bale/29 m2 of floor space within houses, respectively. Treatments were applied in one of two houses on a commercial farm, and were replicated over six production cycles. Both houses had windows and were also artificially lit. Behaviour was observed in weeks 3 to5 of the cycle. This involved observations of general behaviour and activity, gait scores (0: perfect to 5: unable to walk) and latency to lie (measured in seconds from when a bird had been encouraged to stand). Production performance and environmental parameters were also measured. SB density had no significant effect on activity levels (P>0.05) or walking ability (P>0.05). However, the average latency to lie was greater in 30SB birds compared with 45SB birds (P<0.05). The incidence of hock burn and podo dermatitis, average BW at slaughter and levels of mortality and culling were unaffected by SB density (P>0.05). The results from this study suggest that increasing SB levels from 1 bale/44 m2 to 1 bale/29 m2 floor space does not lead to significant improvements in the welfare of commercial broiler chickens in windowed houses.

Results are reported from four trials in which neonatal calves were given either whole milk or milk substitute containing the lactoperoxidase system.

Trial 1 was a pilot trial conducted in Sweden in which calves given whole milk with the lactoperoxidase system gained significantly more weight than controls (P < 0·05). Trials 2, 3 and 4 were carried out in successive years at the National Institute for Research in Dairying, using large numbers of newborn, female Friesian calves. In trial 2 a significant positive effect of the lactoperoxidase system with whole milk on live-weight gain was established by 3 weeks of age (P < 0·05) and sustained until weaning at 5 weeks. There was no significant effect of the lactoperoxidase system for the milk substitute treatment. In trial 3 the whole milk comparison from trial 2 was repeated. There was a significant positive effect of the lactoperoxidase system on the live-weight change after 2 weeks of age only (P < 0·05). In trial 4 two different methods of activating the lactoperoxidase system were compared for calves given whole milk. There was no effect of either method on the live-weight gain of the calves. However, as the levels of scouring were extremely low for all calves, a comparison of the two methods of activating the lactoperoxidase system was not justified. The combined results from trials 2, 3 and 4 confirmed that the lactoperoxidase system significantly increased the live-weight gain of calves given whole milk, despite the fact that the overall level of mortality and incidence of scouring was low in these trials.

The time constraints of the classic twice-daily milking routine are less easily endured by individual dairy farmers, because of their impact on quality of life. Our aim was to evaluate milk production responses by dairy cows milked twice daily at contrasting intervals. In experiments 1 (20 cows) and 2 (28 cows), four milking regimes were compared during a 3-week period beginning after the peak of lactation. Three groups of five cows were milked twice daily (TDM) with milking intervals of 11 : 13, 7 : 17 and 3 : 21 h in experiment 1, and three groups of seven cows at 11 : 13, 5 : 19 and 2.5 : 21.5 h in experiment 2. One group (five and seven cows respectively) was milked once daily (ODM) in each experiment. In experiment 3 (three groups, 12 cows per group), one group was milked at 10 : 14 h and one at 5 : 19 h, and the third group once daily. Milking treatments began during the second week of lactation and continued for an average of 23 weeks. In experiments 1 and 2, daily milk yields were reduced by 4.1%, 11.5% and 28%, for the 5 : 19, 3 : 21 and ODM milking treatments compared with the 11 : 13 h interval. In experiment 3, the decrease in daily milk yields for 5 : 19 h and ODM was 10% and 40% compared with the 10 : 14 h time interval. In the average daily milk, fat and protein contents and somatic cell counts were not different between the TDM groups, and the ODM group had (or tended to have) a higher fat and protein content. For a given milking, milk fat content decreased from about 60 to 32 g/kg as the preceding milking interval increased from 2.5 to 3 h up to 12 h. It then levelled out and even increased, mainly after 18 to 20 h. Somatic cell count showed a similar trend, and protein content did not change steadily. Dry matter intake, body weight and body condition score were not affected by contrasting milking intervals. After resumption of TDM with conventional intervals, productions of milk, fat and protein no longer differed between the TDM groups. Milk yield of previously ODM cows remained lower by 2 kg/day (P = 0.15) in experiments 1 and 2, and by 7 kg/day (P < 0.05) in experiment 3. These results suggest that TDM at contrasting intervals up to 5 : 19 h is feasible as it decreases milk yield only moderately, especially if implemented from peak of lactation.

Amniotic fluid (AF) is important for the establishment of maternal behaviour in inexperienced ewes, but its role in experienced mothers remains to be studied. Here, the maintenance of post-partum maternal responsiveness and the establishment of exclusive bonding was investigated in multiparous ewes when AF was removed from the neonate or/and physical contact with the young was precluded for the first 4 h post partum. Maintenance of maternal responsiveness and establishment of exclusive bonding were measured by the proportion of mothers accepting their own lamb and alien lambs that had been either washed or not washed, and by comparing an acceptance score for each type of lamb. The acceptance score was computed by summing standardised variables of acceptance (low bleats, acceptance at udder, nursing and licking time) and subtracting standardised variables of rejection (high-pitched bleats, rejection at the udder and aggressive behaviour). Washing the neonate reduced its acceptance score, but the proportion of mothers rejecting their own lamb was reduced only when washing the neonate and prevention of physical contact for 4 h were combined (7/15 v. 0/10 in controls, P = 0.02). In addition, washing the neonate increased the acceptance score of the washed alien lamb, but not of the unwashed alien. However, washing and privation of physical contact did not increase significantly the proportion of mothers accepting an alien lamb at 4 h post partum. We conclude that AF is important in experienced ewes for the establishment of maternal responsiveness, as already found in primiparous mothers. In addition, our results indicate that AF also carries some chemosensory information facilitating exclusive bonding.

The transition from gestation to lactation is marked by significant physiological changes for the individual cow such that disease incidence is highest in early lactation. Around the time of calving, cows rely on mobilisation of body energy reserves to fill the energy deficit created by an increase in nutrient demands at a time of restricted feed intake. It is well established that monitoring of body energy reserves in lactation is an important component of herd health management. However, despite their influence on future health and productivity, monitoring of body energy reserves in the dry period is often sparse. Further, there is increasing concern that current dry off management is inappropriate for modern cattle and may influence future disease risk. This study aimed to identify candidate indicators of early lactation production disease from body energy data collected in the dry period and production data recorded at the time of dry off. Retrospective analysis was performed on 482 cow-lactations collected from a long-term Holstein-Friesian genetic and management systems project, the Langhill herd in Scotland. Cow-lactations were assigned to one of four health groups based on health status in the first 30 days of lactation. These four groups were as follows: healthy, reproductive tract disorders (retained placenta and metritis), subclinical mastitis and metabolic disorders (ketosis, hypocalcaemia, hypomagnesaemia and left displaced abomasum). ANOVA, employing a GLM was used to determine effects for the candidate indicator traits. Cows which were diagnosed with a reproductive tract disorder in the first 30 days of lactation experienced a significantly greater loss in body energy content, body condition score and weight in the preceding dry period than healthy cows. The rate of change in body energy content during the first 15 days of the dry period was −18.26 MJ/day for cows which developed reproductive tract disorder compared with +0.63 MJ/day for healthy cows. Cows diagnosed with subclinical mastitis in the first 30 days of lactation had significantly greater milk yield at dry off in the previous lactation than cows that developed a reproductive tract disorder or metabolic disease in addition to a significantly higher yield to body energy content ratio at dry off than healthy cows. Physiological and production traits recorded in the lactation and dry period preceding a disease event differed between cows which developed different diseases post-calving. Differences in these traits allow the development of new disease indicators for use in models for the prediction of disease risk in the transition period.

Knowledge of the capabilities and limitations of the reproductive capacity of bulls is vital in maximizing reproductive efficiencies. Bull semen collection guidelines established by researchers and industry personnel to maximize the sperm harvest from bulls have been evolving for more than 60 years. Today, a mature artificial insemination industry employs those strategies to meet demands. These efficient management schemes exploit the reproductive potential of each sire while minimizing the associated risk of injury to bulls and reduce associated production costs. Personnel employed by a semen producing facility must be authorized to make effective and rational decisions based on principles of bull sexual behavior and reproductive physiology. Furthermore, collection facilities must be well planned to allow for the safe presentation of novel sexual situations while affording maximum safety for employees and proper footing for bulls. Normal bulls produce and ejaculate tremendous numbers of sperm. Most bulls have a sufficient libido for routine sexual activity, but become satiated to predictable stimulus situations. Frequent changes to the novelty should allow weekly harvest of four to six ejaculates per week for most bulls. Utilizing the physiological characteristics associated with each ejaculate to establish the collection frequency of each bull, and empowering an integrated collection and laboratory staff to monitor and make adjustments to the ejaculation frequency are necessary in maximizing the sperm harvest. Young bulls can ejaculate 10 to 20 billion sperm per week, and mature bulls should ejaculate 40 to 60 billion sperm per week. Semen collection management procedures should be reviewed when bulls do not meet production goals.

The objective of this study was to evaluate the addition of IGF-I to pig insemination doses stored at 15°C, in conjunction with the addition of different amounts of vitamin E (α-tocopherol). Semen samples (n = 12) from four boars were treated by the addition of different concentrations of vitamin E, ranging up to 400 μg/ml. Immediately after processing and after the doses had been stored at 15°C for 24 or 72 h, samples were warmed at 37°C and 30 ng/ml of IGF-I was added. The assessments were made after 10 and 120 min of IGF-I addition. There was a minor effect of the vitamin E added before cooling and IGF-I added after storage on sperm quality. The addition of 400 μg/ml of vitamin E to diluted semen reduced (P < 0.01) the malondialdehyde (MDA) production in boar semen stored at 15°C for 72 h, regardless of the addition of IGF-I as additive during a 120 min incubation period at 37°C. In these conditions, IGF-I also reduced (P < 0.05) the MDA production in semen samples without addition of vitamin E. IGF-I in the presence of vitamin E reduced (P = 0.03) the glucose intake in freshly diluted boar semen samples before cooling. It was concluded that the addition of 400 μg/ml of vitamin E reduces the MDA production in boar semen stored at 15°C for 72 h, regardless of the presence of IGF-I additive. The addition of IGF-I in doses stored for 72 h with vitamin E ensures higher sperm motility after 120 min of incubation at 37°C.

Data from 38000 Large White litters farrowed in 146 British herds were analysed to investigate the relative importance of various sources of variation affecting litter productivity. The effects of the season and the year of farrowing were very small relative to the effect of the herd of farrowing which was particularly large on the litter and average pig weights at three weeks. There was a small increase in the size of gilt litters as the age of the gilt at first farrowing increased. Litter size increased progressively with parity up to around the fourth litter and then declined gradually at higher pari-ties. There was a suggestion that the sire of a litter may hve a very small effect on litter size at birth but not at three weeks or eight weeks.