A two-year (2015 and 2016) grazing study was established to compare ewe and lamb performance when grazed on a perennial ryegrass only sward compared to more diverse sward types. In that study four sward types were investigated: a perennial ryegrass (Lolium perenne) only sward receiving 163 kg nitrogen per hectare per year (N/ha/yr) (PRG); a perennial ryegrass and white clover (Trifolium repens) sward receiving 90 kg N/ha/yr (PRGWC); a six species sward (two grasses (perennial ryegrass and timothy (Phleum pratense)), two legumes (white and red clover (Trifolium pratense)) and two herbs (ribwort plantain (Plantago lanceolata) and chicory (Cichorium intybus)) receiving 90 kg N/ha/yr (6S); and a nine species sward containing cocksfoot (Dactylis glomerata), greater birdsfoot trefoil (Lotus pedunculatus) and yarrow (Achillea millefolium) in addition to the six species listed above, receiving 90 kg N/ha/yr (9S). Each sward type was managed as a separate farmlet and stocked with 30 twin-rearing ewes at a stocking rate of 12.5 ewes/ha under rotational grazing management from turnout post-lambing until housing. Lamb live weight was recorded fortnightly and lambs were drafted for slaughter at 45 kg. Ewe live weight and body condition score (BCS) were recorded on five occasions annually. Lamb faecal egg count (FEC) was recorded fortnightly and lambs were treated with anthelmintics when mean lamb FEC per sward type was above 400 eggs per gram. Ewes grazing the 6S and 9S swards had heavier (P < 0.01) live weights and BCS throughout the study than the ewes grazing the PRG sward. Lambs grazing the 6S sward were heavier than lambs grazing all other sward types of 14 weeks old (P < 0.05). Lambs grazing the PRG sward required more days to reach slaughter weight than lambs grazing all other sward types (P < 0.001). Lambs grazing the 6S and 9S swards required fewer anthelmintic treatments than lambs grazing the PRG or PRGWC swards. In conclusion, grazing multispecies swards improved ewe and lamb performance and reduced the requirement for chemical anthelmintics.

Herbage from the same timothy/meadow fescue/white clover sward was ensiled at four different dry matter contents. The resulting silages had dry matter contents of 19·0, 27·3, 32·3 and 43·2%, the dry matter content increasing with the length of the wilting period. An experiment was carried out to determine the voluntary intake of the silages. Each silage was given to 7 animals individually, the mean live weight of these being 334 kg.

Although the silages made from wilted herbage were lower in digestibility than that made from unwilted herbage, wilting increased dry matter intake and metabolizable energy (ME) intake. The mean daily intakes of digestible organic matter were 53·0, 58·1, 59·6 and 59·6 g/kg W0·73, for silages of increasing dry matter content. The corresponding ME intakes, expressed as a multiple of the ME requirement for maintenance, were 1·17, 1·29, 1·30 and 1·28. The percentage of acetic acid in the silage dry matter was significantly (r = −0·56) and linearly related to voluntary intake. The relationship between lactic acid concentration and voluntary intake was significantly curvilinear (r = 0·48).

Operant conditioning was used to measure the effect on the feeding motivation (hunger) of pigs of diluting nutrient restricted food allowances with straw. Twelve Large White × Landrace boars were maintained in individual pens where they received their daily food allowance. Prior to the experiment, the boars were conditioned in separate rooms to press a panel so as to receive small rewards of food. The effect of diluting meal with straw on panel pressing was investigated in two trials. In trial 1, the boars were allocated to the following treatments: high (H) (3·5 of maintenance (A/)), low (L) (1·5 M) and low/straw (LS) (1·5 M + 0·15 times the dry weight of meal as chopped straw). This dilution increased the food volume by proportionately 0·29. Operant response rates were measured in six 1-h tests in each of two periods at the start (days 3 to 10, period 1) and at the end (days 20 to 28, period 2) of the 28-day experiment. In trial 2, nine of the above boars were allocated to the following treatments: high (H) (3·0 A/), low (L) (1·5 M) and low/straw (LS) (1·5 M + 0·30 the dry weight of meal as ground straw). This dilution increased the food volume by proportionately 0·75. Operant response rates were measured as above between days 10 to 17, following a 9-day adjustment period to the new regimes.

In both trials, operant response rate was strongly affected by treatment. Overall in trial 1, animals on the H treatment made few responses (mean 60 responses per session), animals on the L treatment made significantly more responses (mean 825, P < 0·001) and animals on the LS teatment significantly more responses yet again (1263, P < 0·05). This last difference was associated with the difficulty of the LS animals consuming all of the diluted diet during period 1. In trial 2, response rates were again higher on the L than on the H treatments. There was, however, no difference between the L and LS treatments (means: 60 v. 1035 v. 1200). Proportionately only 0·04 of the diet was refused during the period of testing.

The present results show that short-term satiety arising from gut distension does not reduce the feeding motivation of animals on chronic nutrient restriction. This suggests that hunger will remain high i n pigs on restricted food allowances, even when they have access to high fibre foods. This hunger will be a potential source of stress, particularly in housing systems involving physical restraint such as tether stalls.

Tropical and sub-tropical climates are characterized by high temperature and humidity, during at least part of the year. Consequently, heat stress is common in Holstein cattle and productive and reproductive losses are frequent. Our objectives were as follows: (1) to quantify losses in production and quality of milk due to heat stress; (2) to estimate genetic correlations within and between milk yield (MY) and milk quality traits; and (3) to evaluate the trends of genetic components of tolerance to heat stress in multiple lactations of Brazilian Holstein cows. Thus, nine analyses using two-trait random regression animal models were carried out to estimate variance components and genetic parameters over temperature–humidity index (THI) values for MY and milk quality traits (three lactations: MY×fat percentage (F%), MY×protein percentage (P%) and MY×somatic cell score (SCS)) of Brazilian Holstein cattle. It was demonstrated that the effects of heat stress can be harmful for traits related to milk production and milk quality of Holstein cattle even though most herds were maintained in a modified environment, for example, with fans and sprinklers. For MY, the effect of heat stress was more detrimental in advanced lactations (−0.22 to −0.52 kg/day per increase of 1 THI unit). In general, the mean heritability estimates were higher for lower THI values and longer days in milk for all traits. In contrast, the heritability estimates for SCS increased with increasing THI values in the second and third lactation. For each trait studied, lower genetic correlations (different from unity) were observed between opposite extremes of THI (THI 47 v. THI 80) and in advanced lactations. The genetic correlations between MY and milk quality trait varied across the THI scale and lactations. The genotype×environment interaction due to heat stress was more important for MY and SCS, particularly in advanced lactations, and can affect the genetic relationship between MY and milk quality traits. Selection for higher MY, F% or P% may result in a poor response of the animals to heat stress, as a genetic antagonism was observed between the general production level and specific ability to respond to heat stress for these traits. Genetic trends confirm the adverse responses in the genetic components of heat stress over the years for milk production and quality. Consequently, the selection of Holstein cattle raised in modified environments in both tropical and sub-tropical regions should take into consideration the genetic variation in heat stress.

The effects of dietary energy level and added fat were studied by comparative slaughter on 60 primiparous rabbit does in different reproductive states. Nine does were slaughtered immediately after their first parturition (preliminary slaughter group) to estimate initial empty body composition. The 51 remaining does were divided into three groups and given diets differing in digestible energy (DE) content: M (11·28 MJ/kg dry matter (DM); H (12·16 MJ/kg DM); F (11·93 MJ/kg DM, obtained by the inclusion of 25 g/kg of animal fat). Thirty-six does (12 per group) were remated 3 to 4 days after parturition, after which 20 does were concurrently pregnant and lactating (LP) and gave birth a second time. At the second parturition these does were slaughtered with their new-born litters. The non-mated or non-pregnant lactating does (LN) were slaughtered at the same time. All litters from the first parturition were weaned at the 30th day of age.

The diets influenced the DE intake (3·11 v. 3·31 and 3·36 MJ/day, P < 0·05) and the milk production (171 v. 180 v. 191 glday, P < 0·05), respectively for the M, H and F diets. The high-energy diets (H and F) significantly modified the final empty body composition. The loss of body fat was proportionately 0·34, 0·36 and 0·39 of the initial body fat and the loss of energy was proportionately 0·17, 0·19 and 0·21 of the initial body energy in the M, H and F groups respectively (P > 0·05) (average of LP and LN does). The maternal diet significantly influenced the weight of the sucking litters (first parturition) at 20 days (2409 and 2454 v. 2629 g, P < 0·05).

The LP does showed lower DE intake, milk yield (from 10 to 30 days) and litter weaning weights than LN does. Between the first and the second parturition, the LP does had a loss of empty body weight and a negative protein balance (-0·06 of the initial content), while the LN does had an increase in live weight and empty body weight and a positive protein balance (+0·11 of the initial content). Both LP and LN does had a negative energy balance (−0·24 v. −0·25, respectively; P < 0·01).

The aim of the present study was to investigate the effect of feeding strategy on the performance of oral stereotypies, such as tongue-rolling and bar-biting, and other behaviours in lactating dairy cows. Thirty–seven cows of the Swedish Red and Wliite breed were randomly assigned into three treatments with different feeding strategies. Cows in treatment (AL) were given food ad libitum during the whole experimental period, which lasted from weeks 3 to 26 post partum. The second group (AL–R) was given food ad libitum during weeks 3 to 14 post partum, thereafter they were given food at a restricted level. The third group (R) was given food at a restricted level during the whole experiment period. All cows were offered a total mixed ration consisting of 650 g concentrate and 350 g forage per kg twice a day and their individual daily food intakes were registered. Behavioural recordings were made for 4 h on a fixed day every 2nd week, where each individual cow was observed every 2nd minute.

During the complete experimental period, 27 out of the 37 cows showed stereotypies; 13 cows in group R, 10 in group AL–R and four in the AL group. The proportions of cows showing stereotypies were not independent of feeding treatment within the respective periods (P < 0·01). The stereotypy levels, counted as the mean frequency of recordings per treatment period, increased significantly between period 1 (lactation weeks 3 to 14) and period 2 (weeks 17 to 26) in group AL–R (P < 0·01) and in group R(P < 0·01), but not in the AL group. In period 2 the R cows had significantly higher stereotypy levels than the cows in the AL–R group (P < 0·01). Group R decreased the time spent eating between the periods (P < 0·001), with the same tendency in group AL–R. The AL group had longer eating time in period 2 than the AL–R (P < 0–001) and the R (P < 0·001) cows. The AL cows had a higher frequency of rumination than the other treatments in period 2 (P < 0·01). Both the AL–R and the R cows increased their activity levels between the periods (P < 0·001 for both). There were also differences between treatments in period 2, where the AL cows were less active than the AL–R (P < 0·05) and the R cows (P < 0·01).

It is concluded that oral stereotypies in dairy cows are highly affected by feeding strategy, where restrictive feeding of a mixed food induces significant increases of stereotypies. The results of this investigation clearly indicate that restricted feeding of a diet with high levels of concentrate has a negative effect on the well being of lactating cows.

Structural changes lead to increasing sizes of dairy herds and a reduction in grazing use. Thus, cows spend more time in the barn and become more exposed to the barn environment. The cubicle surface can result in damages of the cows’ hock joint integument. Pasture is generally seen as a beneficial environment for cows. We hypothesized that a higher number of daily grazing hours reduce the probability of hock joint alterations in dairy cows from large herds. In total, 3148 lactating cows from 36 grazing and 20 zero-grazing dairy herds, with an average herd size of 173 cows, were assessed individually on one randomly selected body side for alterations in hock integument (score 0 for no alterations or hairless areas <2 cm, 1 for at least one hairless area of ⩾2 cm, 2 for lesion or swelling). The cows were further assessed for lameness and cleanliness. Information on breed, parity and days in milk per cow was extracted from a national database. Cubicle surface was evaluated for each herd. Daily grazing hours 30 days before herd visits were recorded by the stockmen and later categorized as follows: zero hours (zero-grazing), few hours (3 to 9) and many hours (>9 to 21). The effects of daily grazing hours and other potential cow and herd-level risk factors were evaluated for their impact on hock integument alterations using a logistic analysis with a multi-level model structure. The probability for hock integument alterations such as hair loss, lesions or swellings decreased with increasing amount of grazing hours (odds of 3 to 9 h 2.2 times and odds of >9 to 21 h 4.8 times lower than of zero-grazing). The probability for only lesions or swellings decreased with >9 to 21 grazing hours (odds 2.1 times) but not with 3 to 9 h (odds 1.0 times) compared with zero-grazing. Lameness, hard cubicle surface and Danish Holstein v. other breeds showed an increasing effect on the probability for integument alterations. Increase in days in milk only showed an increasing effect on the probability for lesions and swellings. We concluded that a long daily stay on pasture is most beneficial for the hock joint integument of a dairy cow.

The effects of duration of fasting on the short-term feeding behaviour of 12 grazing and 12 silage-fed lactating Holstein-Friesian dairy cows were examined. Four groups of three cows were rotated around fasting treatments of 1, 3, 6 or 13 h following a balanced Latin-square design. Herbage intakes for each treatment group were assessed over al-h period.

As intended there were no significant differences in sward characteristics between the experimental plots grazed by cows from different treatment groups. However, total dry-matter (DM) intake, biting rate and DM intake per bite, measured over the 1-h grazing period, increased significantly when the duration offasting was extended from 1 to 6 or 13 h (P < 0·05). There were only minor differences in grazing behaviour following fasting durations ofl and 3, or 6 and 13 h.

In a parallel study, undertaken to assess the influence offasting duration on appetite independently of grazing, four groups of three cows were housed indoors and offered 30 kg of a high quality grass silage. Silage DM intakes, measured over a 1-h period, increased significantly with extended fasting periods (P < 0·01), though silage DM intake was considerably lower than that of grazing cows for each fasting treatment.

These results suggest that dairy cows grazing on good quality swards may be able to compensate for increased degree of hunger by increasing both biting rate and DM intake per bite to increase DM intake rate. Although the DM intakes of silage and grazed grass followed similar patterns of increasing intake with extended fasting duration, DM intake rates were considerably higher in grazing cows for each fasting treatment.

The first objective of this experiment was to investigate the effect of using different bacterial isolates on the estimation of microbial protein production in semi-continuous fermenters (RUSITEC) given four diets, and to test whether a ‘mixed’ bacterial pellet was representative of the whole bacterial population in the fermenters. A second objective was to compare two different microbial markers (nitrogen-fifteen (15N) and purine bases (PB)). Diets consisted of neutral-detergent fibre from grass hay (10 g/day) and sugar-beet pulp (2 g/day) and 280 mg/day of one of four N forms (isolated soya-bean protein, soya-bean peptides, amino acids blended to profile soya-bean protein and NH4Cl). Two 14-day incubation runs were carried out and in each run each of the four different diets were given to two vessels. On days 12 and 13, total digesta (effluent plus nylon bags residues) was collected for analyses of non-ammonia N, 15N enrichment and PB concentration, and for isolation of total mixed bacterial pellets (TB). On the last day of each incubation run, the system was stopped for isolation of liquid- (LAB) and solid-associated (SAB) bacteria. Microbial N flow was estimated from the 15N enrichment and PB concentration in both total digesta and in the three different bacterial pellets (TB, LAB, and SAB). For all diets, LAB presented a greater (P < 005) 15N enrichment and PB: N ratio than SAB, with TB having an intermediate value. For both markers, the use of LAB produced the lowest (P < 005) estimates of microbial N flow and the use of SAB produced the greatest (P < 005) estimates. The use of TB produced intermediate values with all diets, suggesting that TB consisted of SAB and LAB. For all bacterial pellets, PB produced greater (P 005) values of microbial N flow than 15N. However, there was a positive relationship (r = 0·883; P 0001; no. = 15) between the values of microbial N flow determined with the two markers when TB were used as reference.

1. Records used to compile the Contemporary Comparisons of 57 Friesian, 8 English Ayrshire and 11 Scottish Ayrshire A.I. bulls, each with at least 100 ‘effective daughters’ were analysed.

2. For each bull, the herd-years were divided into three equal groups on the basis of the average heifer yield of both daughters and contemporaries (high-, medium-, and low-producing herd-years) and three independent Contemporary Comparisons were calculated for each bull, one at each of the three yield levels.

3. In the data from England and Wales, the mean Contemporary Comparison declined with increasing mean level of production. This decline was such as to imply that some 20% of the differences in production between herds were genetic in origin. A possible explanation lies in the gradual change from Dairy Shorthorn to Friesian and Ayrshire which has taken place in England and Wales, but not in Scotland, during the last 15 years.

4. The variance within progeny groups within herd-years increased from the low level to the high but the coefficient of variation decreased slightly. The variance between sires also increased with the mean level of production but almost exactly in parallel with that within sires so that the heritability and consequently the accuracy of the progeny test for milk yield was effectively the same at all production levels.

5. The correlation between the true breeding values of the bulls at the different levels was very close to one.

6. From these results it is concluded that there is no need to provide special strains within breeds to suit particular management levels or to concentrate progeny testing in the higher-producing herds and that daughter records from all herds, irrespective of level of production, can be used with equal confidence.

In 22 cows given complete diets of 500 g straw and 500 g concentrates per kg fresh weight the outflow rate of small fibrous particles was determined on two occasions to investigate the consistency of this measurement and its association with apparent digestibility. The correlation between the outflow rates on the two occasions were r = +0·90 and the correlation with apparent digestibility was r = −0·80.

In a second experiment, the outflow rates of long and small particles were determined together with rumen retention time. There was no difference between outflow rate of long and small particles but rumen retention times were greater with the long particles. The correlation between the two estimates of outflow rate was r = +0·84. The outflow rate of fish meal was found to be 0·070 while that of short fibrous particles was 0·031 per h. The average liquid outflow rate was 0·146 per h.

The three cows with the highest outflow rate and the three with the lowest outflow rate from experiment 2 were selected for experiment 3. While voluntary food intakes of the two groups were similar, the differences in outflow rates between the cows persisted both with ad libitum and restricted intakes of both a high and a low roughage diet. The differences were reflected in significant differences between the two groups in apparent digestibility of the diets. The practical implications for breeding and selection are discussed.

The effects of four diets differing in their for age: concentrate ratio (80:20, 60:40, 40: 60 and 20:80; g/100 g fresh matter) on rumen characteristics, digestibility and digesta flow kinetics were investigated. Alfalfa hay was used as forage and concentrate was composed of barley, soya-bean meal and maize. Diets were prepared by mixing all ingredients and offered to the animals as complete diets. Eight mature Merino sheep, each fitted with a rumen cannula, were offered 1·055 kg dry matter per day of the corresponding diet over two experimental periods. The daily evolution of ruminai pH, volatile fatty acids (VFA) and ammonia nitrogen (N) concentrations were measured. Digestibility was determined by total faecal collection and Cr and Co were used as markers to estimate digesta passage rates. Microbial nitrogen flow at the duodenum (MNDF) was estimated from the urinary excretion of purine derivatives (PD). The apparent digestibility of organic matter increased (P < 0·001) whereas that of all fibrous fractions decreased linearly (P < 0·05) as the proportion of concentrate in the diet increased. Rumen pH decreased linearly (P < 0·001) with increasing proportions of concentrate but total VFA concentrations were unaffected by changes in the diet (P > 0·05). Both liquid and solid digesta outflow rates from the rumen decreased quadratically (P < 0·01) as the proportion of concentrate in the diet increased. The urinary excretion of total N, urea-N and ammonia-N was unaffected (P > 0·05) by changes in the diet. In contrast, the daily urinary excretion of both allantoin and total PD increased quadratically (P < 0·05) with increasing proportions of concentrate. Consequently, the estimated MNDF increased linearly (P < 0·001) from 9·9 g/day on the high forage diet to 14·5 g/day on the high concentrate diet.

Physiological differences between cows in hormone and metabolite concentrations were sought that may account for genetic differences in milk production.

Two groups of New Zealand Friesian cows, differing in genetic merit for fat production (high breeding index (HBI) and low breeding index (LBI)) by approximately 23 breeding index units (20 kg fat on the United Kingdom improved contemporary comparison scale), were each divided into two further groups, one of which was given freshly cut pasture to appetite and in the other intake was restricted to 70% of appetite. Eighteen blood samples were collected over a 24-h period from each of 16 cows fitted with indwelling jugular catheters. Samples were analysed for growth hormone, insulin, free fatty acids and β-hydroxybutyrate. Mean concentration of insulin was significantly higher in the HBI underfed group than in any other group (P < 0·01). Glucose concentration was significantly lower in the LBI group (P < 0·05), whose intake was restricted. The concentration of (3-hydroxybutyrate was significantly higher in the cows whose intake was restricted (P < 0·01) and the concentration fell markedly after feeding. Growth hormone concentrations were higher in the cows on restricted intake (P < 0·05) and in HBI cows but the differences were not statistically significant.

It was concluded that different patterns of blood metabolites and hormones are associated with cows that differ in genetic merit. Aspects of insulin and glucose metabolism, particularly at low planes of feeding, appear to offer most promise as indicators of high milk-solids production.

Crossbred pigs (n=720; average age=28±3 days and weight=9.5±0.3 kg) were used in a 20-day trial in order to determine the influence of phosphorus (P) source and various doses of pharmacological zinc (Zn) on growth performance, plasma minerals and mineral digestibility. Pigs (five intact males and five females per pen) were randomly allotted to treatments in a 3×3 factorial arrangement with three sources of dietary P (4.5 g/kg digestible P, 4.5 g/kg digestible P plus 2500 phytase units (FTU)/kg, or 5.5 g/kg digestible P) and three dietary levels of supplemental Zn (0, 1750 or 3500 mg/kg) from ZnO (82% Zn) with eight pens per treatment. Diets were formulated to exceed all nutrient requirements, including calcium (Ca), P and Zn from day 0 to 20. Zn supplementation increased (quadratic P<0.05) average daily feed intake. There was a significant Zn level×P source interaction on average daily gain and feed conversion ratio (FCR). Pigs fed 4.5 g/kg digestible P without or with 2500 FTU/kg phytase gained more per day (quadratic P<0.05) and had better FCR (quadratic P<0.05) when they were fed 1750 mg/kg supplemental Zn. However, pigs fed 5.5 g/kg digestible P gained more per day (linear P<0.05) and were more efficient (linear P<0.05) when they were fed 3500 mg/kg supplemental Zn. Plasma Zn and Zn digestibility increased (linear P<0.05) as pharmacological Zn supplementation increased from 0 to 3500 mg/kg, irrespective of P source. However, Ca, P, sodium (Na), potassium (K) and copper (Cu) digestibility were reduced (P<0.05) as pharmacological Zn supplementation increased, and this was mitigated or exacerbated by the supplementation of 5.5 g/kg digestible P or phytase. In conclusion, increasing the dietary inclusion of pharmacological Zn may impact growth performance in young pigs through the interaction with minerals such as Ca, P, Na and K. Pharmacological Zn may reduce Na or K digestibility and indirectly reduce water secretion into the lumen, resulting in an increase in faecal dry matter as pharmacological Zn supplementation in the diet increased.

Bruises in cattle develop after the application of force, and they provide evidence for sub-optimal animal welfare. The aim of this study was to describe the gross characteristics of bruises in cows arriving at the slaughterhouse directly from farms or through the livestock market. The number of bruises and their distribution on the carcass as well as their severity, shape, size and colour were assessed post mortem in a slaughterhouse in Chile. A total of 258 cow carcasses were evaluated, and a total of 846 bruises were found on 243 of the carcasses. Cows that had passed through a livestock market (M-carcasses) had in total 563 bruises (mean 3.8 bruises/carcass, s.d. 2.0), whereas cows transported directly from farms (F-carcasses) had in total 283 bruises (mean 2.5 bruises/carcass, s.d. 1.8). The backs of F-carcasses had twice as many bruises as M-carcasses (32.9% and 16.2%, respectively), whereas bruises in the rib area were more frequently observed in M-carcasses (13.1%) than in F-carcasses (8.1%). Superficial bruises (grade 1) were the most frequently observed (66.2% of all bruises). Regarding the size of the bruises, 64 (7.6%) were classified as large, 271 (32.0%) as medium and 511 (60.4%) as small. Irregularly shaped bruises were the most frequent (91.1%, n = 771), followed by linear (3.8%, n = 32), circular (3.1%, n = 26) and tramline-shaped bruises (1.9%, n = 16). The latter were noticed only in M-carcasses, which may indicate that these animals were beaten more frequently with sticks or other rod-shaped objects. Fresh, bright red-coloured bruises were found more frequently on all the animals (69.5% from farms and 70.5% from market) compared with bluish (29.7% and 29.3%, respectively) and yellow bruises (0.4% and 0.2%, respectively). The method of selling was significantly associated with the number of bruises on the carcass (P < 0.001) and the anatomical site (P < 0.05), but not with the severity, shape and colour of the bruises. Increased fat coverage reduced the severity of bruises (P < 0.001). This study shows that, in Chile, market animals have more bruises than those sourced directly from farms, and their distribution is different. More information about the causes of infliction may help reduce bruises and it may also improve their welfare. Further studies are required to elucidate whether the causes of the high bruising in the case of animals passing through markets are related only to extra handling (repeated loading, unloading, transportation, eventual mixing) or to the way of handling by personnel and inadequate design.

The aim of this study was to investigate the accuracy to predict detailed fatty acid (FA) composition of bovine milk by mid-infrared spectrometry, for a cattle population that partly differed in terms of country, breed and methodology used to measure actual FA composition compared with the calibration data set. Calibration equations for predicting FA composition using mid-infrared spectrometry were developed in the European project RobustMilk and based on 1236 milk samples from multiple cattle breeds from Ireland, Scotland and the Walloon Region of Belgium. The validation data set contained 190 milk samples from cows in the Netherlands across four breeds: Dutch Friesian, Meuse-Rhine-Yssel, Groningen White Headed (GWH) and Jersey (JER). The FA measurements were performed using gas–liquid partition chromatography (GC) as the gold standard. Some FAs and groups of FAs were not considered because of differences in definition, as the capillary column of the GC was not the same as used to develop the calibration equations. Differences in performance of the calibration equations between breeds were mainly found by evaluating the standard error of validation and the average prediction error. In general, for the GWH breed the smallest differences were found between predicted and reference GC values and least variation in prediction errors, whereas for JER the largest differences were found between predicted and reference GC values and most variation in prediction errors. For the individual FAs 4:0, 6:0, 8:0, 10:0, 12:0, 14:0 and 16:0 and the groups’ saturated FAs, short-chain FAs and medium-chain FAs, predictions assessed for all breeds together were highly accurate (validation R2 > 0.80) with limited bias. For the individual FAs cis-14:1, cis-16:1 and 18:0, the calibration equations were moderately accurate (R2 in the range of 0.60 to 0.80) and for the individual FA 17:0 predictions were less accurate (R2 < 0.60) with considerable bias. FA concentrations in the validation data set of our study were generally higher than those in the calibration data. This difference in the range of FA concentrations, mainly due to breed differences in our study, can cause lower accuracy. In conclusion, the RobustMilk calibration equations can be used to predict most FAs in milk from the four breeds in the Netherlands with only a minor loss of accuracy.

Sensory quality of pork is a complex phenotype determined by interactions between genetic and environmental factors. This study aimed at describing the respective influences of breed and production system on the development of pork quality. Plasma stress indicators and Longissimus muscle (LM) composition, physicochemical and sensory quality traits were determined in two contrasted breeds – the conventional Large White (LW, n=40) and the French local Basque (B, n=60). Pigs were reared in either a conventional (C; n=20 per breed), alternative (A; sawdust bedding and outdoor area, n=20 per breed) or extensive system (E; free-range, n=20 B). All the pigs from A and C systems were slaughtered at the same slaughterhouse, whereas B pigs from the E system were slaughtered at a local commercial abattoir. Major breed differences were found for almost all traits under study. LM from B pigs exhibited higher lipid, lower water and collagen concentrations, as well as lower collagen thermal solubility (P<0.001). Although plasma stress indicators at slaughter did not differ between breeds, except lower (P<0.05) lactate levels in B pigs, they exhibited higher LM pH1 and pHu values, and lower meat lightness, hue angle, water (drip, thawing and cooking) losses, glycolytic potential and shear force. Sensory analyses highlighted higher redness, marbling, tenderness, juiciness and flavour scores (P<0.01) of meat from B compared with LW pigs. Within both LW and B breeds, compared with C, the A system did not (P>0.05) influence plasma stress indicators, LM chemical composition and physicochemical or sensory traits of pork. In contrast, within the B pigs, the E system affected the meat quality more. Lower plasma cortisol levels (P<0.05), but higher plasma lactate, creatine kinase and lactate dehydrogenase activities, and more skin lesions (P<0.05), indicating higher muscular activity during pre-slaughter handling, were found in pigs produced in the E compared with the C system. E pigs exhibited higher meat pH1 and pHu values and shear force (P<0.01) and exhibited lower lightness, hue angle and drip and thawing losses (P<0.01) compared with the C pigs, whereas LM lipid, protein or collagen concentrations were not affected. Regarding sensory traits, the E system produced redder meat, but did not impact the eating quality of pork. Altogether, this study demonstrates that differences in meat quality between B and LW breeds can be modulated by extensive pig production system.

This paper demonstrates how interactions between host genotype for resistance to an infectious disease and the epidemiology of that disease can have large influences on animal productivity and hence on breeding goals for domestic livestock. This is illustrated for the case of gastro-intestinal parasitism in lambs. A model of the parasite infection was developed to include between-animal variation (genetic, permanent and temporary environmental) for live-weight gain, food intake, larval establishment rate in the host, worm fecundity and worm mortality rate. Achieved live-weight gain was defined as the sum of potential live-weight gain under conditions of no parasite infection, a trait correlated with food intake and growth-rate reduction due to the infection. The reduction in growth-rate was calculated from cumulative larval challenge and cumulative worm mass in the lamb. Genetic parameters were then estimated for the output traits of observed live weight at 6 months of age, growth rate reduction and faecal egg count. Model parameters were chosen so that the output means and heritabilities for faecal egg count and live-weight gain mimicked field data for Scottish Blackface lambs and growth-rate reductions were proportionately 0·25 , on average. The model predicted a weak phenotypic correlation (mean = -0·10) between observed live weight and faecal egg count, the indicator of resistance but a stronger favourable (negative) genetic correlation between these traits (mean = -0·27). The severity, or epidemiology, of the disease greatly influenced the results - the genetic correlation between observed live weight and faecal egg count strengthened from -0·02 to -0·46 as the disease severity changed from mild to severe. Selection for reduced faecal egg count resulted in large correlated increases in live-weight gain, more than twice that predicted by quantitative genetic theory, due to the reductions in growth rate losses as the disease challenge to the animals decreased. Conversely, selection for increased live-weight gain resulted in reductions in faecal egg count close to expectations. This asymmetry of selection response emphasizes the epidemiological benefits obtainable from selection for resistance to infectious chronic diseases - such selection will result in improvements in both animal health and productivity not seen when selection is for improved productivity, alone. Breeding goals should be designed to take account of such effects.

Current Welfare Code recommendations suggest one nipple drinker per 10 pigs, while farmers have often used a ratio of one per 20 animals. This statement is based on information from pig farmers and advisors in the United Kingdom. Neither approach is based on empirical investigation. The use of larger group sizes in commercial herds raises further questions, since the relationship between group size and the appropriate number of drinking points cannot be assumed to be linear. The aim was to assess the two conflicting drinker allocations for their effect on welfare, as measured by drinking behaviour, social behaviour and performance, and any effect of group size on these. A total of 640 Large White × Landrace growing pigs were assigned to four treatments in a 2 × 2 factorial arrangement (60 pigs, three drinkers; 20 pigs, one drinker; 60 pigs, six drinkers and 20 pigs, two drinkers). Drinker provision had no significant effect on water use (5.10, 3.88, 4.99 and 3.45 s.e. 0.231 I per pig per day respectively) but in a larger group more water was used in less drinking time (P < 0.001). The diurnal pattern of water use was similar for each treatment. More aggression occurred at the drinker in large groups with a poorer drinker allocation (11.0 v. 3.8% of drinking bouts terminated by aggression for 60 pigs with three drinkers and mean all other treatments respectively, P < 0·05). Overt aggression (2.22, 2.27, 1.76 and 2.07 (s.e. 0.284) aggressive acts per pig per h, respectively) and lesion score counts of a sample of pigs from each pen suggested no difference between treatments. Providing one drinker per 20 animals, even in a large group, did not affect drinking behaviour, social behaviour or production. These findings should not be extrapolated to situations of different ambient temperature, water flow rate or feeding strategy.