Mixing aggression intensity is associated with age at first service and floor type during gestation, with implications for sow reproductive performance.

Aggression resulting from mixing to establish a dominance hierarchy is a major welfare concern for group-housed sows. The associated stress can negatively impact aspects of reproductive performance. Objectives of this study were to investigate associations between 1) age at first service (AFS) and mixing aggression intensity in first parity sows, 2) mixing aggression intensity and reproductive performance within and between parity one and parity two, and 3) mixing aggression intensity, floor type during gestation and reproductive performance. Gilts (n =160, hereafter referred to as sows) were mixed into stable groups of eight unfamiliar individuals approximately 4 days after artificial insemination, housed on fully slatted concrete (CON; n =80) floor uncovered or covered with rubber slat mats (RUB; n =80), and followed through two parities. Skin lesions (SLMIX; a proxy for the intensity of mixing aggression), were scored post mixing in each parity according to severity (0=no lesions to 5=severe lesions) on five body regions (ear, neck, hindquarter, rump, and belly) on the left and right sides, and at the tail/anogenital region. Total SLMIX score was calculated for each sow. Data on reproductive performance traits were acquired retrospectively from farm records for both parities. Two analyses were performed: 1) data from each parity were analysed separately and 2) SLMIX score in parity one was used to predict reproductive performance in parity two. Lower AFS was associated with a lower SLMIX score in parity one (P =0.031). There was no association between SLMIX score and reproductive performance in parity one, while sows with higher SLMIX score in parity two had a higher proportion of piglets dead during lactation (P =0.027) and a longer cycle length (P =0.003) in parity two. Sows with higher SLMIX scores in parity one had more non-productive days (P <0.001) in parity two. Concrete sows had a higher SLMIX score than RUB sows in parity one (P =0.015), but not in parity two. In addition, CON sows had a higher proportion of piglets born dead (P =0.013) compared with RUB sows in parity two. Mixing aggression has a negative influence on reproductive performance within parities, and it may also have a long-term negative carry-over effect on reproductive performance in subsequent parities. Serving gilts at younger ages could help to minimize the intensity of aggression at mixing, while housing on rubber flooring has beneficial implications for their reproductive performance.

Assessing whether dairy cow welfare is "better" in pasture-based than in confinement-based management systems.

Consumers perceive pasture-based systems of milk production as natural and therefore better for cow welfare than confinement systems. However both systems are heterogeneous and continually evolving, varying from total confinement to total pasture with many hybrid intermediaries. To compare the welfare of dairy cows in these various systems, we use the three spheres framework, comprising biological functioning, natural behaviour and affective states. Considering biological functioning, pasture-based cows are less at risk of subclinical and clinical mastitis, claw lesions, lameness, metritis, early embryonic mortality, culling and mortality, but at more risk of internal parasitism, malnutrition and delayed onset of oestrous activity postpartum than confined cows. Regarding natural behaviours, pasture-based cows exhibit less agonistic behaviour, better lying behaviour, more normal oestrous behaviours and better synchronicity of behaviours than confined cows. They also have the opportunity to graze, which is one of the main features of the behavioural repertoire of dairy cows, but, they may also experience long periods away from pasture in larger herds, and severe climatic stresses which will become increasingly important as the climate changes. Our current ability to assess the affective state of dairy cows is poor. For example, hunger is an important subjective state that cannot be measured directly. The growing focus on ensuring that animals have lives worth living, means that dairy cows should garner some positive emotions from their lives, and it seems clear that pasture access is essential for this. Clearly measurement of affective state is an important challenge for future dairy cow welfare research. At the extremes of management systems, there can be major differences in animal welfare but in hybrid systems, dairy cows experience elements of both confinement and pasture which may ameliorate the negative effects of each on cow welfare. Ultimately, the optimal system gives cows an element of choice between both environments. Moreover management of the system, whether it is confinement or pastured-based, may be as important as the system of management in ensuring good dairy cow welfare and addressing societal concerns.Abbreviations: BCS: Body condition score; TMR: Total mixed ration.

Nurse sow strategies in the domestic pig: I. Consequences for selected measures of sow welfare.

Management strategies are needed to optimise the number of piglets weaned from hyper-prolific sows. Nurse sow strategies involve transferring supernumerary new-born piglets onto a sow whose own piglets are either weaned or fostered onto another sow. Such 'nurse sows' have extended lactations spent in farrowing crates, which could have negative implications for their welfare. This study used 47 sows, 20 of which farrowed large litters and had their biggest piglets fostered onto nurse sows which were either 1 week (2STEP7, n=9) or 3 weeks into lactation (1STEP21, n=10). Sows from which piglets were removed (R) were either left with the remainder of the litter intact (I) (remain intact (RI) sows, n=10), or had their litters equalised (E) for birth weight using piglets of the same age from non-experimental sows (remain equalised (RE) sows, n=9). Piglets from 2STEP7 were fostered onto another nurse sow which was 3 weeks into lactation (2STEP21, n=9). Back-fat thickness was measured at entry to the farrowing house, at fostering (nurse sows only) and weaning. Sows were scored for ease of locomotion and skin and claw lesions at entry to the farrowing house and weaning. Salivary cortisol samples were collected and tear staining was scored at 0900 h weekly from entry until weaning. Saliva samples were also taken at fostering. Data were analysed using GLMs with appropriate random and repeated factors, or non-parametric tests were applied where appropriate. Back-fat thickness decreased between entry and weaning for all sows (F 1,42=26.59, P<0.001) and tended to differ between treatments (F 4,16=2.91; P=0.06). At weaning RI sows had lower limb lesion scores than 2STEP7 and RE sows (χ 2 4=10.8, P0.05) and all nurse sows had a higher salivary cortisol concentration at fostering, compared with the other days (F 10,426=3.47; P<0.05). Acute effects of fostering differed between nurse sow treatments (F 2,113=3.45, P0.05). In conclusion, no difference was detected between nurse sows and non-nurse sows in body condition or severity of lesions. Although some nurse sows experienced stress at fostering, no long-term effect of the nurse sow strategies was detected on stress levels compared with sows that raised their own litter.

Nurse sow strategies in the domestic pig: II. Consequences for piglet growth, suckling behaviour and sow nursing behaviour.

Nurse sow strategies are used to manage large litters on commercial pig farms. However, new-born piglets transferred to nurse sows in late lactation might be compromised in terms of growth and survival. We investigated the effects of two nurse sow strategies on piglet growth, suckling behaviour and sow nursing behaviour. At 1-day post-farrowing, the four heaviest piglets from large litters were transferred to a nurse sow either 21 (1STEP21, n=9 litters) or 7 (2STEP7, n=10 litters) days into lactation. The remainder of the litter remained with their mother and was either kept intact (remain intact (RI), n=10 litters) or had some piglets cross-fostered to equalise birth weights (remain equalised (RE), n=9 litters). The 7-day-old piglets from 2STEP7 were transferred onto a sow 21 days into lactation (2STEP21, n=10 litters). The growth of new-born piglets on 1STEP21 and 2STEP7 nurse sows was initially lower than in RI litters (F 3,33.8=4.61; P<0.01), but weaning weights did not significantly differ (F 4,32.7=0.78; P>0.5). After the 1st week of lactation, the weights and growth rates did not differ between treatments. Fighting behaviour during nursing bouts decreased over time. The frequency of fights was higher in 1STEP21 and 2STEP21 litters compared with RI litters (t 122=3.06 and t 123=3.00, respectively, P<0.05). The 2STEP21 litters had shorter nursing bouts than RI and 1STEP21 litters (t 107=-2.81 and t 81.7=2.8, respectively, P<0.05), which were more frequently terminated by 2STEP21 than RI sows (t 595=2.93; P<0.05). Transferring heaviest piglets from RI and RE litters to nurse sows reduced the percentage of teat changes during nursing bouts (RI: F 1,275=16.61; RE: F 1,308=43.59; P<0.001). In conclusion, nurse sow strategies do not appear to compromise piglet growth. However, new-born piglets transferred onto sows in late lactation experienced more competition at the udder, suggesting that the sows' stage of lactation is of importance to how achievable nurse sow strategies are. Thus, the two-step nurse sow strategy is likely the best option (in relation to growth and suckling behaviour), as it minimises the difference between piglet age and sow stage of lactation.

Identifying physiological measures of lifetime welfare status in pigs: exploring the usefulness of haptoglobin, C- reactive protein and hair cortisol sampled at the time of slaughter.

BACKGROUND: Physiological measures indicative of the welfare status of animals during rearing could form part of an abattoir-based animal health and welfare assessment tool. A total of 66 pigs were used in this study, the aim of which was to assess how serum concentrations of haptoglobin (Hp) and C-reactive protein (CRP) (assessed in 51 pigs), and hair concentrations of cortisol (assessed in 65 pigs), measured at or close to slaughter, reflected welfare-related indicators recorded from the animal during its lifetime. These indicators were recorded at intervals between 7 and 21 weeks of age and included assigning scores for levels of tail and skin lesions, recording the presence or absence of certain health issues, and conducting qualitative behavioural assessments (QBA). RESULTS: Pigs recorded as having tail lesions during their lifetime had higher hair cortisol levels than those with no tail lesions (tail lesions: 47.87 ± 3.34 pg/mg, no tail lesions: 42.20 ± 3.29 pg/mg, P = 0.023), and pigs recorded as having moderate or severe tail lesions had higher Hp levels than those with no or mild tail lesions (moderate/severe: 1.711 mg/ml ± 0.74, none/mild: 0.731 mg/ml ±0.10, P = 0.010). Pigs recorded as being lame during their lifetime tended to have higher hair cortisol levels than non-lame pigs (lame: 52.72 pg/mg ± 3.83, not lame: 43.07 pg/mg ± 2.69, P = 0.062). QBA scores were not associated with any of the physiological measures (P > 0.05). Receiver Operator Curve (ROC) analysis was also carried out to get a better understanding of the usefulness of the physiological measures in discriminating animals that had had welfare-related issues recorded during their lifetime from those that had not. Hair cortisol was determined as having 'moderate' accuracy in discriminating pigs that were tail bitten on-farm from unbitten pigs (AUC: 0.748) while Hp and CRP were determined to have no meaningful discriminatory ability (AUC < 0.600). CONCLUSION: This research should be repeated on a larger scale, but the results suggest that hair cortisol measured at slaughter could provide insight into the welfare status of pigs during their lifetime. Hp may be a useful indicator of tail lesions in pigs. However, further research utilising a greater proportion of severely bitten pigs is required before conclusions can be drawn.

Validation of carcass lesions as indicators for on-farm health and welfare of pigs.

Incorporating indicators for pig health and welfare at meat inspection could reduce the need for on-farm assessments. Skin and tail lesions are important welfare indicators in pigs with good potential to record during meat inspection and could possibly function as iceberg indicators of on farm welfare. The aim of this study was to validate the use of these carcass lesions at meat inspection for the assessment of pig health and welfare on farm. Thirty-one farrow-to-finish pig farms (∼12% of Irish herds) were assessed using an adapted version of the Welfare Quality protocol by inspecting 6 randomly selected pens of pigs in the first weaner (4 to 8 wk), second weaner (8 to 13 wk) and finisher stage (13 to 23 wk). The average prevalence of welfare outcomes for each stage was calculated. One batch of pigs was observed at slaughter and skin and tail lesions were scored according to severity for each carcass. The average prevalence of carcass lesion outcomes was calculated for each farm. Linear regression models were developed to predict the prevalence of each welfare outcome in each stage based on the prevalence of the different carcass lesions. The welfare outcomes of different welfare aspects that were best predicted by abattoir information (highest ) were poor body condition (first weaner stage), bursitis (second weaner stage), huddling (first weaner stage), severe tail lesions (finisher stage) and coughing (second weaner stage). Regression trees and receiver-operating curves (ROC) were used to evaluate the usefulness of carcass lesions as monitoring tools. Receiver-operating curves were created using the 75th percentile to classify farms as a problem farm for these welfare outcomes. Cut-off values of predictive carcass lesion prevalence were similar using both techniques. Models for predicting problem farms with poor body condition, bursitis and severe tail lesions were moderately accurate. Sensitivity and specificity ranged from 75 to 100% and 70 to 87%, respectively at the optimal cut-off value of the predictive carcass lesion prevalence. Results show potential for using carcass skin and tail lesions as iceberg indicators of pig health and welfare on farm. Future work is needed to evaluate the cost of including carcass lesion recording at meat inspection, the cost of failing to identify problem farms and the cost of incorrectly visiting or penalizing problem farms before carcass lesions can be used as welfare indicators in a commercial setting.

Pig carcass tail lesions: the influence of record keeping through an advisory service and the relationship with farm performance parameters.

Tail lesions are important pig welfare indicators that could be recorded during meat inspection as they are more visible on the carcass than on the live animal. Tail biting is associated with reduced performance in the bitten pig, but it is not clear whether problems with tail biting are reflected in general farm performance figures. Farm advisory services aim to improve farm productivity which could be associated with improvements in pig welfare. Record keeping forms an integral part of such advisory services. The aim of this study was to examine the influence of record keeping in the Teagasc eProfit Monitor (ePM herds) on the prevalence of tail lesion severity scores in Irish slaughter pigs. In addition, we investigated associations between the prevalence of tail lesion scores and production parameters at farm level in ePM herds. Pigs were observed after scalding/dehairing and tail lesion score (0 to 4), sex and farm identification were recorded. Tail lesion scores were collapsed into none/mild lesions (score ⩽1), moderate lesions (score 2) and severe lesions (score ⩾3). The effect of record keeping (ePM herd) on the different tail lesion outcomes was analysed at batch level using the events/trials structure in generalized linear mixed models (PROC GLIMMIX). Spearman's rank correlations were calculated between average tail lesion score of a batch and production parameters. A total of 13 133 pigs were assessed from 73 batches coming from 61 farms. In all, 23 farms were identified as ePM herds. The average prevalence of moderate tail lesions was 26.8% and of severe tail lesions was 3.4% in a batch. Batches coming from ePM herds had a lower prevalence of moderate tail lesions than non-ePM herds (P<0.001). Average tail lesion score was negatively associated with age (P<0.05) and weight (P<0.05) at sale/transfer of weaners, and tended to be positively associated with the number of finishing days (P=0.06). In addition, the prevalence of severe tail lesions was negatively associated with average daily gain in weaners (P<0.05) and tended to do so with average daily gain in finishers (P=0.08). This study provides the first indication that record keeping through an advisory service may help to lower the risk of tail biting, which is associated with improved farm performance.

Effects of scalding and dehairing of pig carcasses at abattoirs on the visibility of welfare-related lesions.

There is increasing interest in developing abattoir-based measures to assist in determining the welfare status of pigs. The primary aim of this study was to determine the most appropriate place on the slaughter line to conduct assessments of welfare-related lesions, namely apparent aggression-related skin lesions (hereafter referred to as 'skin lesions'), loin bruising and apparent tail biting damage. The study also lent itself to an assessment of the prevalence of these lesions, and the extent to which they were linked with production variables. Finishing pigs processed at two abattoirs on the Island of Ireland (n=1950 in abattoir A, and n=1939 in abattoir B) were used. Data were collected over 6 days in each abattoir in July 2014. Lesion scoring took place at two points on the slaughter line: (1) at exsanguination (slaughter stage 1 (SS1)), and (2) following scalding and dehairing of carcasses (slaughter stage 2 (SS2)). At both points, each carcass was assigned a skin and tail lesion score ranging from 0 (lesion absent) to 3 or 4 (severe lesions), respectively. Loin bruising was recorded as present or absent. Differences in the percentage of pigs with observable lesions of each type were compared between SS1 and SS2 using McNemar/McNemar-Bowker tests. The associations between each lesion type, and both cold carcass weight and condemnations, were examined at batch level using Pearson's correlations. Batch was defined as the group of animals with a particular farm identification code on a given day. The overall percentage of pigs with a visible skin lesion (i.e. score>0) decreased between SS1 and SS2 (P<0.001). However, the percentage of pigs with a severe skin lesion increased numerically from SS1 to SS2. The percentage of pigs with a visible tail lesion and with loin bruising also increased between SS1 and SS2 (P<0.001). There was a positive correlation between the percentage of carcasses that were partially condemned, and the percentage of pigs with skin lesions, tail lesions and loin bruising (P<0.05). In addition, as the batch-level frequency of each lesion type increased, average cold carcass weight decreased (P<0.001). These findings suggest that severe skin lesions, tail lesions and loin bruising are more visible on pig carcasses after they have been scalded and dehaired, and that this is when abattoir-based lesion scoring should take place. The high prevalence of all three lesion types, and the links with economically important production parameters, suggests that more research into identifying key risk factors is warranted.

A cross-sectional study on the prevalence and risk factors for foot and limb lesions in piglets on commercial farms in Ireland.

A cross-sectional survey of 68 integrated Irish pig farms was conducted to determine the prevalence and risk factors for foot and limb lesions in 2948 piglets from 272 litters. One litter was selected per age category; 3-7 days, 8-14 days, 15-21 days and 22-28 days per farm. All piglets were examined for sole bruising, sole erosion, coronary band injuries, limb abrasions, alopecia, swollen limbs and swollen feet and scored from 0 to 3 based on relative size. Environmental parameters were recorded for each litter examined. A questionnaire was completed on management, health and performance factors for each farm. The overall prevalence of each lesion was calculated and multilevel mixed effect logistic regression models were used to elucidate risk factors. The prevalence (farm range) of lesions were: sole bruising=61.5% (7-100%), sole erosion=34.1% (0-100%), coronary band injuries=11.3% (0-46%), limb abrasions=55.7% (11-98%), alopecia=24.8% (0-83%), swollen limbs=2.4% (0-11%) and swollen feet=4.4% (0-14%). Age was negatively associated with sole bruising (OR 0.42; CI 0.37, 0.50) and coronary band injury (OR 0.69; CI 0.60, 0.81) and positively associated with limb abrasions (OR 1.54; CI 1.12, 2.14). There was a reduced risk of sole bruising in piglets in pens with plastic slats with oval voids in the piglet area of the pen with a plastic solid area for piglets and metal slats under the crate (OR 0.32; CI 0.15, 0.70) compared with plastic stats throughout and a plastic solid area for piglets. There was an increased risk of sole erosion (OR 1.81; CI 1.07, 3.09) and foot and limb swellings (OR 1.90; CI 1.01, 3.57) in pigs in pens with metal slats only and a solid plastic area for piglets compared with plastic stats throughout and a solid plastic area for piglets. There was an increased risk of coronary band injury in pens with metal slats throughout and a metal solid area for piglets (OR 4.25; CI 1.96, 3.57) compared with plastic stats throughout and a plastic solid area for piglets. We conclude no single floor type was ideal for piglet foot and limb health with all floors influencing different lesions in different ways, however, the positive association between sole erosions, coronary band injury and foot and limb swellings and metal slats suggest that this floor type was most detrimental and most likely to be associated with joint infections that lead to severe health and welfare concerns.

Effects of gestation housing system and floor type during lactation on locomotory ability; body, limb, and claw lesions; and lying-down behavior of lactating sows.

This study evaluated the influence of housing system during gestation and floor type during lactation on the welfare and lying-down behavior of lactating sows. Multiparous sows (n = 85) were housed either in individual gestation stalls (n = 42) or loose (n = 43) in a single dynamic group with 2 electronic sow feeders moved to farrowing crates on either slatted steel (n = 48) or cast iron (n = 37) flooring. Lameness (0 = normal to 5 = severely lame) was scored on transfer to the farrowing crate (-5 d). Limb and body lesions were recorded on -5 d, 24 h after entering the farrowing crate (-4 d), 10-d postpartum, and before weaning. Claw lesions were recorded on -5 d and before weaning, whereas all behavioral observations were made on -5, -4, and 10 d. Median (Me) scores were calculated for claw, body, and limb lesions and classified as either less than or equal to the Me or greater than the Me lesion scores. Sows were classified as nonlame (≤ 1) or lame (≥ 2). Loose-housed sows had an increased (P < 0.01) risk of lameness; a reduced (P < 0.05) risk for claw lesions, particularly white line damage, horizontal wall cracks, and dewclaw injuries; and a reduced (P < 0.05) risk for calluses and bursitis on the limbs compared to stall-housed sows. Sows housed on cast iron floors during lactation had a reduced (P < 0.01) risk for heel overgrowth and erosion and heel-sole cracks compared with sows on slatted steel floors. There was no (P > 0.05) association between flooring type during lactation and body lesion score. On -4 d, loose-housed sows had a shorter latency to lie down (P < 0.01), spent more time inactive (P < 0.05), and shifted weight between the limbs more often (P = 0.05) while standing compared with stall-housed sows. Lame sows had a shorter (P < 0.01) latency to lie down compared to nonlame sows on -5 and -4 d. In conclusion, there was an increased risk of lameness in sows housed loose compared to those housed in gestation stalls on transfer to the farrowing crate. Claw health deteriorated in the farrowing crate regardless of gestation housing or floor type but the deterioration in claw health was increased on slatted steel compared to on cast iron.

Longitudinal study of the effect of rubber slat mats on locomotory ability, body, limb and claw lesions, and dirtiness of group housed sows.

This study evaluated the influence of floor type on sow welfare with particular focus on lameness, claw lesions (CL), and injuries. The study used 164 gilts housed in groups of 8 from AI to 110 d of pregnancy in pens with concrete (n = 84) slatted floor left uncovered or covered by 10-mm rubber slat mats (n = 80) through 2 parities. Lameness (0 = normal to 5 = severe), limb (0 = normal to 6 = severe) and body (0 = normal to 5 = severe) lesions, and manure on the body (MOB; score 0 to 2) were recorded at AI, 24 to 72 h postmixing, between 50 and 70 d of pregnancy, and 2 wk before farrowing. Claw lesions (score 0 = normal to 3 = severe) were recorded at AI and between 50 and 70 d of pregnancy. The dirtiness and wetness of the floors was scored weekly (score 0 = clean to 4 = >75% of the pen soiled/wet). Data from the first and second parities were analyzed separately. Sows were categorized as nonlame (score ≤ 1) or lame (score ≥ 2). Median (M(e)) scores were calculated for CL and body and limb lesions and were classified as less than or equal to the median or greater than the median lesion scores. Sows on rubber slat mats had a reduced risk of lameness during both parities (P < 0.01) compared with sows on concrete. They also had an increased risk of scores greater than the median for toe overgrowth (M(e) = 2 and M(e) = 3 in the first and second parity, respectively) and heel sole crack (HSC; M(e) = 3) during both parities (P < 0.01) and for cracks in the wall (CW; M(e) = 4) and white line damage (WL; M(e) = 4; P < 0.01) in the first and second parity, respectively. There was a reduced risk of lameness in sows with scores greater than the median for HSC (P = 0.05) in the first parity and WL (M(e) = 3; P < 0.01) and CW (M(e) = 3; P < 0.05) in the second parity. Wounds (M(e) = 3) and severe lesions (M(e) = 0) on the limbs with scores greater than the median were associated with an increased risk of lameness (P < 0.01) in the first and second parity, respectively. Sows on rubber slat mats had a reduced risk of scores greater than the median for swellings (M(e) = 4) and wounds (P < 0.01) during both parities. Pens with rubber slat mats were dirtier than uncovered pens (P < 0.01); however, there was no association between MOB and flooring type. There was also no association between body lesion score and flooring type. In this study, CL were not associated with an increased risk of lameness. Therefore, even though rubber slat mats were associated with an increased risk of CL, they improved the welfare of group housed sows by reducing the risk of lameness and limb lesions.

The influence of a magnesium-rich marine extract on behaviour, salivary cortisol levels and skin lesions in growing pigs.

Growing pigs can display undesirable behaviours, reflecting or causing poor welfare. Addition of magnesium (Mg) to the diet could reduce these, as Mg supplementation has been associated with improved coping ability in response to stress. This study examined the effect of supplementation with a Mg-rich marine extract-based product (Supplement) on the behaviour, skin and tail lesion scores and salivary cortisol concentrations of growing pigs. At weaning (28 days), 448 piglets were assigned to either Control or Supplement (0.05%) diets in single-sex groups of 14. Four weeks later (c. 17 kg), pigs were blocked according to weight and back test scores. Seven piglets from each pen were mixed with seven from another pen of the same sex and dietary treatment to yield the following groups: control male, Supplement male, control female and Supplement female (n = 4 of each). This marked the start of the 9-week experimental period. Instances of the following behaviours were recorded in each pen for 8 × 2 min periods 1 day/week: aggression (fight, head-knock and bite); harmful (tail-in-mouth, ear-chewing and belly-nosing); and sexual/mounting behaviour. Four focal pigs were selected from each pen, and their behaviour was continuously recorded for 2 × 5 min periods on the same day. Saliva was collected once per week at 1000 h by allowing pigs to chew on a cotton bud for c. 1 min. Salivary cortisol was analysed in duplicate by an enzyme immunoassay. Skin and tail lesions were scored according to severity 1 day/week. There were fewer aggressive incidents in Supplement pens (P < 0.01), and mounting behaviour (performed only by males) was almost three times lower in Supplement than in control pens (P < 0.01). However, there was no effect of Supplement on the incidence of each of the harmful behaviours. Behaviour of the focal pigs showed no treatment effect on the duration or incidence of aggressive behaviour. However, Supplement pigs spent less time performing harmful behaviours compared with control pigs (P < 0.001). Supplement had no effect on the occurrence or severity of tail-biting outbreaks or on tail lesion scores. However, Supplement females had lower skin lesion scores, in particular in the ears and shoulders (P < 0.01). Finally, Supplement pigs had lower salivary cortisol concentrations (P < 0.01). Mounting is a major welfare concern in uncastrated pigs, and therefore this represents an important welfare benefit of Supplement. Reduced salivary cortisol, in conjunction with reduced skin lesion scores in supplemented females, suggests that addition of a Mg-rich marine extract improved pig welfare in this system.

Effect of split marketing on the welfare, performance, and carcass traits of finishing pigs.

The aim of this study was to compare a split marketing (SM) strategy, in which the heaviest pigs in a group are removed and slaughtered earlier than the others, with an all-out (AO) marketing strategy, in which all pigs are removed from the pen simultaneously and slaughtered on the same day, in terms of welfare, performance, and carcass traits of noncastrated (i.e., intact) male and female pigs. The experimental treatments were arranged in a 2 × 2 factorial array with 1) marketing strategy (SM vs. AO) and 2) sex (males vs. females), which yielded 4 treatment groups of 14 pigs (73.1 ± 4.8 kg): male SM, male AO, female SM, and female AO (7 replicates/group). Pigs in AO groups were all slaughtered after 6 wk on trial, whereas in SM groups the 3 heaviest pigs were removed and slaughtered 2 wk before the remainder of the group, which were slaughtered at the same time as the AO pigs. Pigs were fed a liquid diet from a long trough 3 times daily. Behavioral observations were conducted before and after SM, the day of SM, and 1 and 2 wk later. Behavior was recorded both during and between feed events, and skin lesions were scored on all, except the 3 pigs removed from SM groups before and 2 wk after SM. Growth performance, feed efficiency, and carcass traits were recorded. The number of aggressive interactions during feed events decreased after the 3 pigs were removed from SM groups. This reduction in aggressive interactions was observed on the day of SM in male groups (before SM: 24.3 vs. the day of SM: 14.7, SED = 3.31, P < 0.05 for interaction) and in subsequent observations in female groups (before SM: 21.4 vs. days after SM: 13.4, SED = 3.31, P < 0.05 for interaction). However, SM had no effect on behaviors recorded between feed events or on the number and severity of skin lesions (P > 0.10). There were no differences between the 11 remaining pigs in SM groups and the 14 pigs in AO groups in terms of growth performance, feed efficiency, and carcass traits of female or intact male pigs (P > 0.10). However, reduced within-pen CV in carcass weight was detected in pigs from SM groups compared with pigs from AO groups (8.6 vs. 10.9, SEM = 0.72, P < 0.05). Therefore, in restrictively fed pigs, a SM strategy improved the welfare of both female and intact male pigs by reducing aggressive interactions during feeding but had no effect on performance or carcass traits.

Strategies to overcome obstacles to successful immunotherapy of melanoma.

The immunogenicity of malignant melanomas has been recognized by the observed recruitment of tumor-specific cytotoxic T-cells (CTL), leading to the identification of several melanoma associated antigen (MAA). However, numerous strategies to treat melanoma with immunotherapy have resulted in only partial success. In this editorial, we discuss recent data related to the ability of tumors to elude immune responses. We therefore discuss different strategies to induce a clinically effective immune response. These approaches include 1) immunostimulation: including peptide/protein based vaccines, dendritic cell vaccines, and adoptive cell transfer; and 2) overcoming immunosuppression, including targeting of checkpoint molecules such as CTLA-4, circumventing the activity of Tregs, and assuring antigen expression by tumor cells (thwarting antigen silencing). Finally, we discuss recent advances in gene therapy, including adoptive therapy with engineered T cell receptors (TCRs). These issues lead to the conclusion that successful immunotherapy in malignant melanoma requires a combination of strategies aimed at both inducing immunostimulation and blocking immunosuppression.

Effects of milking frequency on phagocytosis and oxidative burst activity of phagocytes from primiparous and multiparous dairy cows during early lactation.

The objective of this study was to investigate the effect of milking frequency on the phagocytosis and respiratory burst activity of polymorphonuclear neutrophils (PMN) and monocytes of primiparous and multiparous cows under 2 nutritional management regimens during early lactation. At calving, 12 primiparous and 12 multiparous cows were randomly assigned to 1 of 4 treatments, in which animals were milked once (OAD) or twice a day at a high or low nutritional level. Blood samples were taken 1 to 7 d before calving (prepartum) and 1 to 7, 14 to 21, and 42 to 49 d postpartum. Phagocytic and oxidative burst activity of PMN and monocytes were determined in whole blood and analyzed separately by flow cytometry. Once-a-day milking reduced significantly the percentage of phagocytic PMN and tended to decrease the number of bacteria ingested by these cells. The percentage of oxidative burst positive cells and overall respiratory burst activity of monocytes also tended to be reduced by OAD milking. The reduction of oxidative burst activity of monocytes was more pronounced 1 to 7 d postpartum compared with the prepartum sample and other postpartum samples. Oxidative burst activity of PMN and monocytes of multiparous cows was impaired compared with primiparous cows. The percentage of oxidative burst positive monocytes from multiparous cows was reduced prepartum and also 1 to 7 d postpartum. Once-a-day milking reduced the mean respiratory burst activity of PMN from primiparous cows to levels similar to that of multiparous cows. Therefore, an OAD milking regimen reduces phagocytic activity of PMN and monocytes and would be detrimental for the immune system in high-yielding dairy cows during early lactation.

Welfare and performance of yearling dairy heifers out-wintered on a wood-chip pad or housed indoors on two levels of nutrition.

Wood-chip pads represent a low-cost alternative to housing for cattle during the winter. Considering the negative welfare implications associated with housing indoors on concrete, they may also offer welfare benefits to replacement dairy heifers. However, these animals may not be able to withstand winter weather conditions on a grass silage diet. The aim of this experiment was to evaluate behaviour, limb injuries, dirtiness scores, performance and climatic energy demand (CED) of yearling dairy heifers on two levels of nutrition kept outdoors on a wood-chip pad or indoors in cubicles during the winter. Ninety-six 10-month-old heifers were blocked and assigned in groups of eight, to one of the following four treatments in a 2 × 2 factorial design: (a) indoors, silage only; (b) indoors, silage plus concentrate; (c) outdoors, silage only; and (d) outdoors, silage plus concentrate. There were three replicate groups per treatment. All animals were inspected for skin lesions and were weighed and body condition scored (BCS) at the beginning and end of the trial. Instantaneous scan sampling and continuous all-occurrence behaviour sampling were used to collect behaviour data during two 24-h periods. Animals were also dirtiness scored and group feed intakes were recorded during the trial. Significantly more comfort, social and play behaviours were recorded outdoors (P < 0.05) while trips, slips and falls were only recorded indoors (P < 0.001). Groups outdoors had significantly lower limb lesion scores at the end of the experiment (P < 0.05) and fewer groups outdoors were affected by all categories of limb lesions. However, they were consistently dirtier than animals indoors (P < 0.001). Low-nutrition animals had lower feed intakes, smaller BCS changes and lower average daily weight gains than high-nutrition animals (P < 0.01). Heifers outdoors had significantly lower average daily weight gains and BCS changes (P < 0.05) explained by lower feed intakes (P < 0.01). However, outdoor heifers on both the high- and low-nutrition diets and indoor animals on the low-nutrition diet had lower UFL (feed unit for maintenance and lactation (Irish Republic)) intakes (-0.36, -0.35 and -0.22, respectively) than that required to meet the daily live-weight gains they achieved. Heifers indoors on the high-nutrition diet gained 0.98 kg per day but consumed 0.17 UFL more than what would be recommended to achieve a daily weight gain of 1.0 kg. The CED for outdoor heifers was higher than that of indoor heifers (6.18 v. 5.47 MJ/day per m2 body surface area; P < 0.001, s.e.d. 0.044). However, CED did not exceed heat production in any treatment. Although animal performance was reduced outdoors, the wood-chip pad was associated with welfare benefits compared with cubicle housing.

Age-related changes in pro-inflammatory cytokines, acute phase proteins and cortisol concentrations in neonatal piglets.

Age-related changes have been described in the resting levels of cortisol and acute phase proteins in the neonatal pig. This study evaluated the plasma concentrations of the pro-inflammatory cytokines tumour necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), the acute phase proteins C-reactive protein (CRP), serum amyloid A (SAA) and haptoglobin (Hp), as well as cortisol during the first week of postnatal life in piglets. The influence of invasive managerial practices such as teeth clipping, ear notching and tail docking on possible age-related changes in the production of these inflammatory mediators was also assessed. A total of 96 piglets were selected from 24 litters at birth, and were randomly assigned to one of four sampling times over the first week of life and one of two treatments. Blood samples were taken at 1, 3, 5 or 7 days of age. Piglets were ear notched, teeth clipped and tail docked (NCD), or were left untreated (CON). Significant effects of age were found in plasma concentrations of TNF-alpha, SAA, Hp and cortisol (p < 0.001). Concentrations of TNF-alpha and Hp increased with age, and peak concentrations were found on day 5. SAA and cortisol levels were highest on day 1, decreasing gradually with age. NCD piglets tended to have higher levels of plasma Hp than CON animals (p = 0.066). However, no differences between NCD and CON piglets were found in any other parameter measured. Furthermore, age effects were not affected by these husbandry practices. These results indicate that age-related changes exist in several inflammatory mediators, and suggest that these managerial practices do not result in systemic inflammation in early postnatal life of piglets.

A novel autocrine pathway of tumor escape from immune recognition: melanoma cell lines produce a soluble protein that diminishes expression of the gene encoding the melanocyte lineage melan-A/MART-1 antigen through down-modulation of its promoter.

We have observed that malignant melanoma cells produce a soluble protein factor(s), which down-regulates melanocyte lineage Melan-A/MART-1 Ag expression by melanoma cells with concomitant loss of recognition by Melan-A/MART-1-specific T cells. This down-modulation of Melan-A/MART-1 expression, which we refer to as "Ag silencing," is mediated via its minimal promoter, whereas the promoter for the restricting Ag-presenting HLA-A2 molecule is not affected. Significantly, this Ag silencing is reversible, as removal of factor-containing supernatants from Melan-A/MART-1-expressing cells results in up-regulation of the promoter for the gene encoding this Ag, and renewed expression of the protein. We have evaluated over 20 known factors, none of which accounts for the Ag-silencing activity of the melanoma cell culture supernatants. The existence of this autocrine pathway provides an additional novel explanation for melanoma tumor progression in vivo in the presence of CTL specific for this melanocyte lineage Ag. These observations may have important implications for Melan-A/MART-1-specific CTL-mediated immunotherapy of melanoma tumors.

Outer membrane protein A, peptidoglycan-associated lipoprotein, and murein lipoprotein are released by Escherichia coli bacteria into serum.

Complexes containing lipopolysaccharide (LPS) and three outer membrane proteins (OMPs) are released by gram-negative bacteria incubated in human serum and into the circulation in an experimental model of sepsis. The same OMPs are bound by immunoglobulin G (IgG) in the cross-protective antiserum raised to Escherichia coli J5 (anti-J5 IgG). This study was performed to identify the three OMPs. The 35-kDa OMP was identified as outer membrane protein A (OmpA) by immunoblotting studies using OmpA-deficient bacteria and recombinant OmpA protein. The 18-kDa OMP was identified as peptidoglycan-associated lipoprotein (PAL) based on peptide sequences from the purified protein and immunoblotting studies using PAL-deficient bacteria. The 5- to 9-kDa OMP was identified as murein lipoprotein (MLP) based on immunoblotting studies using MLP-deficient bacteria. The studies identify the OMPs released into human serum and into the circulation in an experimental model of sepsis as OmpA, PAL, and MLP.

Release of gram-negative outer-membrane proteins into human serum and septic rat blood and their interactions with immunoglobulin in antiserum to Escherichia coli J5.

Prior studies indicate that 3 bacterial outer-membrane proteins (OMPs) are released into serum associated with lipopolysaccharide (LPS) and are bound by IgG in antiserum to Escherichia coli J5 (anti-J5 IgG). The present studies analyzed the interaction of the OMPs with anti-J5 IgG and evaluated their release in an infected burn model of gram-negative sepsis. Affinity purification studies were performed on filtrates of bacteria incubated in human serum and plasma from rats with sepsis by use of O chain-specific anti-LPS IgG and anti-J5 IgG. All 3 OMPs were captured from septic rat blood by anti-LPS IgG. Release of OMPs into serum was highest for immature bacterial cultures and was increased by antibiotics in vitro and in vivo. Anti-J5 IgG selectively captured an 18-kDa OMP released into serum and into plasma from septic rats. The results raise the possibility that anti-J5 IgG may, in part, protect via anti-OMP antibodies.