Weaner Stage Research Articles

Prevalence of tail damage and ear lesions in docked and undocked pigs during trials to find alternatives to tail docking on Spanish commercial farms.

Tail docking is widely used to control tail biting in pigs, but it is a painful and stressful procedure. The impact of non-docking trials on tail damage (TD) and ear lesions (EL) from weaning to slaughter was assessed on four commercial farms. A total of 898 docked pigs (396 DP) or undocked pigs (502 UP) were assessed for tail damage and ear lesions at the beginning and end of the weaner stage, during fattening and at the abattoir during slaughter. The percentage of UP with shortened tails increased significantly from weaning to fattening, but the percentage of non-inflamed tails and tails without fresh lesions increased. In terms of severity of lesion, a lower percentage of pigs scored as 'no visible lesion' at the end of weaning compared to fattening, both for UP and DP (p<0.05). DP always had a lower percentage of TD, whereas UP had a lower percentage of EL at the end of weaning. It was not possible to statistically compare different preventive strategies trialed on farms as alternatives to docking. This study highlights that combining tail length and lesion score at slaughter could be a reliable on-farm welfare indicator.

Analysing biomarkers in oral fluid from pigs: influence of collection strategy and age of the pig

Background and objectivesOral fluid (OF) is an easy-to-collect, inexpensive, fast and non-invasive sample to characterize health and welfare status of the pig. However, further standardisation of the collection methods is needed in order to use it regularly in veterinary practice. Cotton ropes are routinely used to collect OF for pathogen detection but they may not be optimal for biomarker analysis due to sample contamination. This study compared two methods (cotton ropes and sponges) to collect porcine OF for biomarker analysis. A panel of 11 biomarkers of stress, inflammation, sepsis, immunity, redox status and general homeostasis was studied.Materials and methodsEighteen farrow-to-finish pig farms were included in the study. In each farm, three (for sponges) or four pens of pigs (for ropes) were sampled at four age categories: the week after weaning (5 weeks), before (11–12 weeks) and after (12–13 weeks) moving to finisher facility and the week before slaughter (22–25 weeks). In total, 288 OF samples were collected with cotton ropes and 216 with sponges and analysed for the biomarkers: cortisol, alpha-amylase, oxytocin (stress), haptoglobin (inflammation), procalcitonin (sepsis), adenosine deaminase, immunoglobulin G (immune system), ferric reducing antioxidant power (redox status), and creatine kinase, lactate dehydrogenase and total protein (general homeostasis). Samples were also scored visually for dirtiness using a score from 1 (clean) to 5 (very dirty).ResultsRope-collected OF had higher levels of dirtiness (3.7 ± 0.04) compared to sponge-collected OF (2.7 ± 0.15) and had higher values than sponges for cortisol, procalcitonin, oxytocin, haptoglobin, total protein, lactate dehydrogenase and ferric reducing antioxidant power. All biomarkers decreased in value with age. Immunoglobulin G did not perform well for any of the two collection methods.Discussion and conclusionThe results showed a clear effect of age on the biomarkers in OF collected with both, sponges or ropes. Sponges provided a cleaner sample than cotton ropes for biomarker analysis. Both methods are easy to apply under the commercial conditions in pig farms although sponges may take more time in early weaner stages. From a practical point of view, sampling with sponges achieved the best combination of reduced sampling time and low contamination.

Comparison of single- and double-spaced feeders with regard to damaging behavior in pigs.

This work compared the behavior and performance of 24 groups of 12 pigs kept in pens with either a DOUBLE [one feed space aligned with the front wall of the pen (WALL), and one immediately adjacent (IN)] or SINGLE (WALL only) spaced feeder, from weaning until slaughter. Pens were equipped with a rack of fresh grass and a rubber toy (weaning phase) or a wooden board (finishing phase). Every 2 weeks, interaction with the enrichment, aggressive, harmful, and play behaviors were recorded for 5 min, four times a day. In addition, the pigs were individually assessed every 2 weeks for ear, tail, and flank injuries using a 4-point scale. The duration of feeder occupancy, feed space occupancy, number of and duration of feeding bouts, and aggressive behavior at the feeder were recorded continuously from video recordings (two times while in the weaner stage and two times while in the finisher stage, one camera/pen; 1 h per occasion). Individual body weight was recorded at weaning, transfer, and slaughter, and feed delivery was recorded daily at the pen level; from these measurements, average daily gain, feed intake, and feed conversion ratio were calculated. Data were analyzed using SAS v9.4. There was no effect of treatment on damaging behaviors. Pigs in DOUBLE had worse tail lesion scores on 6 of the 9 recording days (P < 0.001), but values rarely exceeded 1. Total feeder occupancy tended to be longer in DOUBLE than in SINGLE (P = 0.06). DOUBLE selected the IN feed space more often than WALL regarding the number of feeding bouts (P < 0.001). During feeding, pigs in DOUBLE received fewer aggressive behaviors than SINGLE (P < 0.001) and experienced fewer displacements than SINGLE (P < 0.001). Although both experimental groups had a similar weight at slaughter (P > 0.05), the FCR was lower in DOUBLE than in SINGLE (P < 0.05). These data suggest that doubling space at the feeder to two spaces/12 pigs reduced aggression and displacement behaviors at the feeder, indicating less competition for food. However, increasing feeder space was not a management strategy that could ensure reduced tail biting on commercial pig farms.

Economic analysis of crossbred (Landrace × Desi) pig reared under different floor space allowances

Present experiment was conducted to study the relative economics of crossbred (Landrace×Desi) pigs with thirty six crossbred barrows reared under 3 different floor space allowances (n=12 each) having group size of 4 pigs/pen. One group (TIS) was provided floor space as per Indian Standards (0.9, 1.35 and 1.8 m2/pig for weaner, grower and finisher stages, respectively) specifications, while other two groups with 33% (T2/3) and 50% (T1/2) reduced floor space allowances. Only covered floor area was provided for all the groups. Different parameters analyzed during the study involved growth, feed conversion efficiency, requirement of water and labour for floor washing, and some other economic variables. Pigs were reared up to 28 weeks of age. Relative economics of pig rearing for three floor space allocation groups was calculated using partial budget analysis. Major performance traits, i.e. average daily gain (ADG) and feed conversion efficiency (FCE) did not differ significantly among the groups. Although body weights of T2/3 and T1/2 groups were marginally higher than TIS group. In contrary to minor savings of labour, large quantity of water was saved in T1/2 and T2/3 groups (805.4 liters/pig and 400.1 liters/pig, respectively) than TIS group between weaner and finisher stages. Additionally, input costs of ₹` 145 and ` ₹ 96 per pig was saved by providing floor space as per T1/2 and T2/3 groups, respectively than TIS group. It can be concluded that economic gains were maximum in 50% floor space reduction group without adverse effect on performance traits of crossbred pigs.

Consequences of timing of organic enrichment provision on pig performance, health and stress resilience after weaning and regrouping

Most pigs in slatted systems are provided with enrichment meeting only minimum legal requirements. We aimed to explore the effects of a novel enrichment treatment consisting of daily provided fodder beet and jute bags for pigs in slatted systems, and investigate the timing of enrichment provision on performance, health and stress resilience. We used 280 weaners allocated into standard (S, meeting only legal requirements consisting of a plastic toy and softwood) or enriched (E) treatment (n = 14 groups/treatment). At regrouping during the grower to finisher transition, pigs were either kept in the same treatment (EE, SS) or switched from enriched to standard (ES) and vice versa (SE); each treatment was replicated on five groups. Pigs were weighted at the start and end of weaner, and finisher stage, and feed intake was recorded. Occurrence of scouring, respiratory problems, locomotor disorders, tail, ear, and body lesions were recorded twice a week. Ten males per treatment were sampled for saliva on days 1, 2 and 4, either postweaning or after the housing switch. Saliva samples were analysed for cortisol, alpha-amylase, haptoglobin (Hp), and adenosine deaminase. Additionally, these pigs were sampled for hair at the start and end of weaner, and end of finisher stage to analyse for hair cortisol and cortisone. We found that E weaners consumed less feed (P = 0.04), had better FCR (feed conversion ratio, P = 0.03) and less ear lesions for two weeks postweaning (P = 0.04), and tended to have lower occurrence of scouring (P = 0.07) and higher salivary cortisol concentrations (P = 0.09) than S weaners. Effects of enrichment treatment during weaner stage on performance were carried through to finisher stage, with EE and ES pigs having better FCR (P = 0.0009) and higher BW (P = 0.0001) compared to SS and SE pigs. E treatment during finisher stage decreased feed intake (P = 0.04) and tended to decrease Hp levels (P = 0.07). There was a significant interaction between enrichment treatments during weaner and finisher stages on finisher body lesions: EE finishers had less lesions than SS, ES, and SE finishers (P = 0.04). There were no other significant differences caused either by enrichment treatment during weaner/finisher stage or their interaction. We conclude that the novel enrichment applied at weaner stage had positive effects on ear lesions and performance, which were carried through to finisher stage. Body lesions were affected by its application during both stages, with finishers receiving the enrichment treatment throughout (EE) having reduced body lesions than the rest of the finishers.

Study of Animal Mixing and the Dynamics of Hepatitis E Virus Infection on a Farrow-to-Finish Pig Farm.

Simple SummaryIn Europe, swine are a livestock reservoir for Hepatitis E virus genotype 3 (HEV-3). Consumption of food containing HEV-3 may lead to human infection, and severe illness in some cases. Heat treatment and good hygiene practice during food preparation reduces human infection risk, but further control could be achieved by controlling HEV infection in pigs on farm. However, the key sources and timing of HEV infection in pig herds is not well understood. This study aimed to address these knowledge gaps. Pig faeces were collected from a farrow-to-finish farm on multiple occasions spanning five months and were tested for presence of HEV nucleic acid. Prevalence was always higher in growers (85.8% overall) compared to older fattener pigs (26.0%), but was detected at all visits indicating long-term persistence on the farm. Prevalence of HEV in the farm environment was also high (64.7% of 67 samples), and this may lead to continual herd re-infection. Studying infection in a single cohort of pigs over time revealed an absence of active infection in farrowing sows and young piglets. Infection first appeared in the cohort at weaner age, but only in groups that had either been weaned earlier or experienced a high degree of mixing with other pigs.In Europe, swine are a livestock reservoir for Hepatitis E virus genotype 3 (HEV-3). Consumption of food containing HEV-3 can cause zoonotic human infection, though risk is reduced by heat treatment. Implementing controls that limit infection in slaughter pigs may further reduce foodborne transmission risk but knowledge of infection dynamics on commercial farms is limited. This study addressed this knowledge gap and in particular investigated the influence of group mixing. Faeces were collected from grower (n = 212) and fattener (n = 262) pigs on a farrow-to-finish farm on four occasions. HEV RNA was detected on all occasions, and prevalence was higher in growers (85.8%) than fatteners (26.0%; p < 0.001). HEV-positive samples were also collected from the wider farm environment (n = 67; 64.7% prevalence), indicating potential sources for HEV re-circulation within the herd. Timing of infection in a cohort was also investigated. HEV was absent from all piglet faeces (n = 98) and first detected at weaner stage (25.7% prevalence), but only in groups weaned earlier or comprising pigs from many different litters. Farrowing sow faeces (n = 75) were HEV-negative but antibodies were detected in blood from two sows. Results suggest that multiple factors influence HEV infection dynamics on pig farms, and potential foci for further study into practical control solutions are highlighted.

Freedom to Grow: Improving Sow Welfare also Benefits Piglets.

Simple SummaryThis study identified positive effects on piglet welfare and growth rates when housed in free lactation pens compared with conventional farrowing crates. Free lactation pens allow piglets unrestricted interaction with the sow and increased space allowance; this improved behavioural development of piglets thus resulted in fewer instances of damaging behaviour toward littermates in this study. Piglets also benefit from better access to the udder for feeding in free lactation pens, with those piglets reared in such pens having better growth rates than those in conventional farrowing crates.Piglet mortality, especially due to crushing, is a concern in pig production. While current systems use farrowing crates to reduce mortality, they present major animal welfare problems for the sow. This study investigated the effects of free lactation farrowing accommodation on the welfare of piglets born and reared in such accommodation when compared with conventional farrowing crates. Piglets were born to sows in one of two farrowing accommodation treatments and followed from birth to slaughter. Treatments were conventional farrowing crates (control, n = 24 litters) and free lactation pens, which were larger and allowed the sow freedom of movement both pre and post farrowing, (free, n = 22 litters) (675 total piglets). Individual weights were recorded from birth to slaughter. Hoof score was recorded at weaning. Behaviour was recorded during lactation and during the weaner stage. Pre-weaning percentage mortality was equal in treatments (free = 15.95 ± 2.31, control = 14.42 ± 2.15, p = 0.61). Final weight was influenced by treatment (p < 0.05) with pigs from free lactation pens significantly heavier at 114.73 kg compared to 110.82 kg for control pigs. Free pigs took fewer days than control pigs to reach the target weight of 105 kg (147.6 vs. 149.23 days). Throughout lactation, fewer instances of damaging behaviour (ear and tail biting) were observed in free pigs (p = 0.07). Improved growth rates and a decrease in damaging behaviours provide evidence to suggest that pigs from free lactation pens experience improved welfare when compared with control pigs.

Financial Analysis of Herd Status and Vaccination Practices for Porcine Reproductive and Respiratory Syndrome Virus, Swine Influenza Virus, and Mycoplasma hyopneumoniae in Farrow-to-Finish Pig Farms Using a Bio-Economic Simulation Model.

This study aimed (1) to quantify the effects of positive status and vaccination practices for porcine reproductive and respiratory syndrome virus (PRRSv), swine influenza virus (SIV) and Mycoplasma hyopneumoniae (MHYO) on the profitability of farrow-to-finish pig farms and (2) to examine the financial impact of vaccination status in PRRSv and SIV positive farms. Data from 56 Irish farrow-to-finish pig farms were used for this study. Production effects associated with herd status for the three pathogens were incorporated into the Teagasc Pig Production Model (TPPM), a bio-economic stochastic simulation model for farrow-to-finish pig farms. In the analysis, farms negative (–) for either PRRSv, SIV or MHYO were assumed as baseline when presenting results for farms positive (+) for each pathogen. While all MHYO(+) farms used vaccination against the pathogen, not all PRRSv(+) or SIV(+) farms vaccinated against the disease. For all scenarios, a 728-sow farrow-to-finish farm with weekly farrowing batches was simulated. Financial risk analysis was conducted by Monte Carlo simulation within the TPPM using the Microsoft Excel add-in @Risk. Mortality rates, feedstuff costs and price per kg of meat produced were included as input stochastic variables and annual net profit was set as stochastic output variable. Positive farms sold fewer pigs and produced less kg of meat than negative farms and had increased feed usage during the weaner and finisher stages. Variable costs increased in positive farms due to increased feed costs, more dead animals for disposal and healthcare costs. Annual mean profit was lower by 24% in vaccinated PRRSv(+), 14.6% in unvaccinated PRRSv(+), 36.7% in vaccinating SIV(+), 12.8% in unvaccinated SIV(+), and 41% in MHYO(+) farms. Negative farms were first order stochastically dominant over positive farms, indicating that for a given level of profit, the financial risk is lower by avoiding respiratory pathogens. Similarly, unvaccinated farms were second order stochastically dominant over vaccinating farms suggesting that farms that do not vaccinate are less affected by the disease. Results from this study provide further evidence to encourage farmers to undertake improved disease control measures and/or to implement eradication programs.

Can increased dietary fibre level and a single enrichment device reduce the risk of tail biting in undocked growing-finishing pigs in fully slatted systems?

This study evaluated the effectiveness of combined dietary and enrichment strategies to manage tail biting in pigs with intact tails in a conventional fully-slatted floor housing system. A 2 × 2 × 2 factorial design was used. Pigs had either a high fibre (weaner 5.3% and finisher 11.6% of crude fibre) or standard fibre diet (weaner 3.7% and finisher 5.9% of crude fibre). In the weaner stage, pigs had either a spruce wooden post (supplied in a wall-mounted dispenser) or a rubber floor toy as a enrichment device, and in the finisher stage, they had either the same or alternate enrichment item. Six hundred and seventy-two pigs were assigned to 48 pens of 14 pigs and followed from weaning until slaughter. Individual tail lesion scores and pen level behaviours were directly recorded every 2 weeks. Twenty-six pens had tail biting outbreaks and 161 injured pigs needed removal for treatment. Pigs fed with the high fibre diet performed more tail biting (p < 0.05) and tended to have a worse tail damage scores than those fed the standard fibre diet (p = 0.08). Pigs which had the floor toy as weaners and wood as finishers tended to have fewer tail lesions in the finisher stage than their counterparts (p = 0.06). Pigs receiving the floor toy as enrichment interacted with the enrichment more frequently overall (p < 0.001) and performed fewer harmful behaviours in the weaner stage (p < 0.05). Overall, higher fibre in the diet in a relatively barren environment did not help reduce tail biting or tail lesions. Altering the fibre level in the pigs' diet and providing a single enrichment device to undocked pigs on fully slatted floors resulted in a high level of tail biting and a large proportion of pigs with partial tail amputation.

An ethogram of biter and bitten pigs during an ear biting event: first step in the development of a Precision Livestock Farming tool

Pigs reared in intensive farming systems are more likely to develop damaging behaviours such as tail and ear biting (EB) due to their difficulty in coping with the environment and their inability to perform natural behaviours. However, much less is known about the aetiology of EB behaviour compared to tail biting behaviour. Application of new intervention strategies may be the key to deal with this welfare issue. The discipline of Precision Livestock Farming (PLF) allows farmers to improve their management practices with the use of advanced technologies. Exploring the behaviour is the first step to identify reliable indicators for the development of such a tool. Therefore, the aim of this study was to develop an ethogram of biter and bitten pigs during an EB event and to find potential features for the development of a tool that can monitor EB events automatically and continuously. The observational study was carried out on a 300 sow farrow-to-finish commercial farm in Ireland (Co. Cork) during the first and second weaner stages. Three pens per stage holding c. 35 pigs each, six pens in total, were video recorded and 2.2 h of videos per pen were selected for video analysis. Two ethograms were developed, one for the biter and one for the bitten pig, to describe their behavioural repertoire. Behaviours were audio-visually labelled using ELAN and afterwards the resulting labels were processed using MATLAB® 2014. For the video data, duration and frequency of the observed behavioural interactions were quantified. Six behaviours were identified for the biter pig and a total of 710 interactions were observed: chewing (215 cases), quick bite (138 cases), pulling ear (97 cases), shaking head (11 cases), gentle manipulation (129 cases) and attempt to EB (93 cases). When the behaviour observed was not certain, it was classified as doubt (27 cases). Seven behaviours were identified for the bitten pig in response to the biters behaviour and were divided in: four non-vocal behaviours described as biting (40 cases), head knocking (209 cases), shaking/moving head (225 cases) or moving away (156 cases); and three vocal behaviours identified as scream (74 cases), grunt (166 cases), and squeal (125 cases). Vocal behaviours were classified using a verified set of features yielding a precision of 83.2%. A significant difference in duration was found between all the behaviours (P < 0.001), except between gentle manipulation and chewing where no difference in duration was found (P < 0.338). The results illustrate the heterogeneity of EB behaviours, which may be used to better understand this poorly studied damaging behaviour. They also indicate potential for the development of a PLF tool to automatically, continuously monitor such behaviour on farm by combining the behaviour of the biter pig and the bitten pigs responses.

Removing prophylactic antibiotics from pig feed: how does it affect their performance and health?

BackgroundAntibiotics (AB) are an important tool to tackle infectious disease in pig farms; however some research indicates that their frequent mis/over-use may contribute to the development of antibiotic resistance and the WHO has declared that this issue should be addressed. Little is known about the long term consequences of withdrawing prophylactic AB from pig feed; hence we aimed to assess its effects on performance and health of pigs from weaning to slaughter.Six batches of 140 pigs each were monitored on a commercial farm through the weaner and finisher stages to slaughter. In-feed antibiotics were not added to the feed for half of the pigs (NOI) and were added in the other half (ABI) within each batch for the whole weaner stage. Individual pigs in both treatments were treated with parenteral administrations if and when detected as ill or lame. Productive performance, parenteral treatments and mortality were recorded on farm and the presence of respiratory disease was recorded at slaughter. Pen was considered the experimental unit.ResultsABI pigs showed higher growth (P = 0.018) and feed intake (P = 0.048) than NOI pigs in the first weaner stage but feed efficiency was not affected (NOI = 1.48 vs. ABI = 1.52). Despite an initial reduction in performance, NOI pigs had similar performance in finisher stage (ADG: NOI = 865.4 vs. ABI = 882.2) and minimal effects on health compared to ABI pigs. No difference between treatments was found at the abattoir for the percentage of pigs affected by pneumonia, pleurisy, pleuropneumonia and abscesses (P > 0.05). Mortality rate was not affected by treatment during the weaner stage (P = 0.806) although it tended to be slightly higher in NOI than ABI pigs during the finisher stage (P = 0.099). Parenteral treatments were more frequent in NOI pigs during the weaner stage (P < 0.001) while no difference was recorded during the finisher stage (P = 0.406).ConclusionsThese data suggest that the removal of prophylactic in-feed antibiotics is possible with only minor reductions in productive performance and health which can be addressed by improved husbandry and use of parenteral antibiotics.

An investigation into the effectiveness of compressed straw blocks in reducing abnormal behaviour in growing pigs

The provision of manipulable material to pigs is a legal requirement to ensure their good welfare. Loose straw is edible, chewable, investigable and manipulable, and has been proven to be effective in reducing abnormal behaviour. However, it is incompatible with slatted systems and therefore not a viable option for many intensive units. Thus, there is a need to identify enrichment materials that are as effective as loose straw and compatible with slatted floors. This study investigated the viability of using compressed straw blocks on a commercial farm in terms of cost and effectiveness in reducing biting relative to plastic hanging toys. A total of 880 slaughter pigs were used, among which half (n = 440, 8 groups) were provided with commercial pig toys (TOY) and the other half (n = 440, 8 groups) were provided compressed straw blocks (STRAW BLOCK). Animals were separated according to sex to investigate whether there was a higher propensity to tail and ear bite depending on sex. Pigs were monitored from weaning to slaughter, with tails being examined post scalding and any condemnations recorded at the abattoir. Throughout their life, the tails and ears of all pigs were examined individually, and behavioural observations of each pig group were conducted fortnightly. Salivary cortisol was also obtained from a subsample of pigs from each group every fortnight to monitor stress levels. The highest straw usage was recorded in the second weaner stage (39 to 67 days after weaning). Enrichment type or sex had no effect on tail lesion scores or cold carcass weight recorded at the abattoir. There was also no effect of enrichment type or sex on body, tail, or ear lesion scores during either the weaner (0 to 39 days after weaning) or finisher stage (67 to145 days after weaning). Female pigs showed more biting behaviour than males, and female pigs that were provided STRAW BLOCK performed better than those provided TOY. In both the weaner and finisher accommodation, more instances of interaction were recorded with TOY pens as enrichment than with STRAW BLOCK, but the interaction duration was not recorded. There was no effect of sex on either stage. More instances of aggression were observed with the TOY than with STRAW BLOCK in the weaner stage (P < 0.05). Enrichment type or sex had no effect on cortisol levels. Thus, relative to plastic hanging toys, compressed straw blocks provided in this manner did not benefit pig welfare.

Behavioural response of crossbred (Landrace × Desi) pigs under different floor space allowances

Present investigation was carried out to study the behaviour of pigs at 33 and 50% reduced floor space allowances in relation to Indian standards (IS: 3916-1966) for housing of pigs. Crossbred (Landrace × Desi) barrows (36) were reared with 3 different floor space allowances (n = 4 (group size) × 3 (replications) = 12 each) i.e. group TIS (control) had floor space allowance as per Indian standards, while T2/3 and T1/2 treatment groups had 33 and 50% reduced floor space allocation per pig. Accordingly, during weaner (6–14 weeks), grower (15–22 weeks) and finisher (23–28 weeks) stages, 3 different floor spaces were provided. During each growth stage (weaner/grower/ finisher), activities of each unit (consisting of 4 animals) were recorded thrice in sessions of 2 consecutive hours (an hour before (preprandial) and after (prandial and postprandial) offering of second meal in afternoon). Total time spent in agonistic activities did not differ among the groups. However, parallel pressing agonistic activity was more in T1/2 group during grower and finisher stages at prandial and postprandial time while in TIS group during weaner stage at preprandial time. Time spent resting was higher in TIS group at prandial and postprandial time during weaner stage while it was higher in T2/3 group during grower stage. Exploratory activities and social interactions were maximum in T2/3 group during weaner and finisher stages and differed significantly from T1/2 group. From behavioural response, it can be concluded that suitable floor space allowance should lie in between 33 to 50% reduction in relation to IS specifications.

Cross-Fostering Implications for Pig Mortality, Welfare and Performance.

This study aimed to (1) identify cross-fostering (CF) practices employed on a commercial farm; (2) characterize CF pigs according to litter of origin traits, and (3) investigate the implications of CF practices on pig mortality, performance and welfare. This was an observational study whereby pigs were managed according to normal farming practice. Pigs (n = 1,016) born within 1 week were classified as non-CF (NCF); CF during the first (CFW1) and second or third (CFW2+) weeks of lactation. Pigs were individually weighed and inspected for the presence of tail (TL), ear (EL) and body lesions (BL) at weaning (7.03 ± 1.61 kg) and at the end of the first (12.9 ± 3.03 kg) and second (31.9 ± 5.50 kg) weaner and grower (66.3 ± 9.12 kg) stages. Mortality was recorded through to slaughter (c. 115 kg). At slaughter, TL were scored and carcass characteristics, presence of pleurisy, enzootic pneumonia, pericarditis and heart condemnations were recorded. 40.8% of CF pigs were CFW1; ANOVA tests revealed these were born to sows with a higher number of piglets born alive than NCF pigs (14.6 ± 2.61 and 12.8 ± 2.68, respectively). The remaining 59.2% of CF pigs were CFW2+; these were, on average, 0.14 kg lighter at birth than NCF pigs. Therefore, a nested case control design was retrospectively applied whereby pigs with complete records to slaughter, were matched for these variables to investigate associations between CF weeks, welfare and performance traits. Growth performance did not differ between CF week (P > 0.05); however, CFW2+ carcasses were 4.9 kg lighter (P < 0.05) compared with NCF and CFW1 pigs. EL were more likely in CFW1 compared to NCF and CFW2+ (P < 0.05) pigs. To investigate the effect of CF week on the risk of mortality, all 1,016 pigs were used. CF pigs were at higher risk of death (P < 0.05) with similar odds in CFW1 and CFW2+ pigs compared with NCF pigs, although other underlying factors could contribute to this result. Performance and health traits were similar between CF weeks. Early cross-fostering appeared to influence the presence of ear lesions but the mechanism is likely indirect and difficult to explain.

Prevalence of welfare outcomes in the weaner and finisher stages of the production cycle on 31 Irish pig farms

BackgroundKnowledge on the most prevalent welfare problems for pigs in different production stages is required to improve herd management plans. Thirty-one farrow-to-finish pig farms were visited between July and November 2015 to assess the welfare of pigs using the multicriteria approach of the Welfare Quality® protocol. On each farm, 6 pens were selected using proportionate stratified sampling in the first weaner (S1, 4 to 8 wks), second weaner (S2, 8 to 13 wks) and finisher stage (S3, 13 to 23 wks), excluding hospital pens. Each pen was observed for 10 min and the number of pigs affected by different welfare outcomes was recorded. The percentage of pigs affected was calculated and ranked to identify the most prevalent outcomes within each production stage. Differences between production stages were analysed using generalised linear mixed models for binomial data with pen within stage and farm as a random effect.ResultsTail and ear lesions showed the highest prevalence; however, large variation was observed between farms. In S1 the most prevalent welfare outcomes (presented as median prevalence) were poor body condition (4.4%), lethargic pigs (1.5%), scouring (20.3% of pens) and huddling (3.7%). In S2 and S3 outcomes related to injurious behaviour (tail lesions: 5.9% [S2] and 10.5% [S3], ear lesions: 9.1% [S2] and 3.3% [S3], and flank lesions: 0.4% [S2] and 1.3% [S3]), lameness (0.8% [S2] and 1.1% [S3]), bursitis (3.9% [S2] and 7.5% [S3]) and hernias (1.6% [S2] and 1.8% [S3]) were more prevalent.ConclusionsA large variation was observed for the recorded welfare outcomes corresponding to the different challenges pigs experience during the different stages of production on commercial pig farms. The prevalence of pigs affected by lesions caused by injurious behavior is a cause for concern and requires a collaborative approach to identify appropriate intervention strategies. This information could be used to further investigate appropriate benchmark values for different welfare outcomes that would assist the pig industry to develop appropriate health and welfare management plans to minimise welfare problems. At herd level such plans should include information on aspects of intervention, treatment, and the management of hospital pens as well as euthanasia.

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.

Carcass traits of crossbred (Landrace × Desi) barrows reared with different floor space allowances under intensive system

Present study assessed the effect of floor space allowances on carcass traits of crossbred (Landrace × Desi) barrows in Indian conditions. Crossbred barrows (36) were reared with 3 different floor space allowances (12 each) having group size of 4 pigs/pen. One group (TIS) was provided floor space as per Indian Standards (0.9, 1.35 and 1.8 m2/pig for weaner, grower and finisher stages, respectively) specifications, while other two groups with 33% (T2/3) and 50% (T1/2) reduced floor space allowances. Pigs were reared up to 29 weeks of age. Final weight of pigs did not differ significantly among the groups. Six animals from each group were slaughtered. None of the major economic carcass traits, viz. carcass weight, dressing %, back fat thickness (BFT), loin eye area (LEA), estimated lean meat percentage etc. was adversely affected. Major cut-up parts, share of edible as well as inedible offal and composition of pork (moisture, CP and EE) also did not differ among groups. It indicates scope of 50 % reduction in floor space allowance for pig production in India without affecting final body weight and major carcass characteristics.

The effects of previous dietary Lys concentration on subsequent growth performance of two different pig genotypes

The aims of this study were to determine whether Lys restriction immediately after weaning could be compensated for when pigs were switched to a high-Lys diet, and to determine whether this may be influenced by genotype. The experiment was a 2×2 factorial arrangement of diets and genotypes with 8 replicate pens per treatment and 8 or 9 mixed sex pigs per pen. Pigs received either a high- (Control; 17.5g/kg of Lys) or a low-Lys (WR; 8.0g/kg of Lys) diet during the first 3 week post-weaning followed by a high-Lys diet (15.5 and 12.0g/kg of Lys during the grower and finisher phases, respectively) to facilitate compensation until slaughter (approximately 101.2 ± 4.9kg). Two hundred and sixty four pigs [132 Hampshire sire×(Large White×Landrace) dam and 132 Large White sire×(Large White× Landrace) dam] were used and are referred to as Hampshire pigs and Large White pigs. Blood samples were collected from 2 selected pigs per pen at 6, 9, and, 15 week of age for blood urea nitrogen (BUN), non-esterified fatty acids (NEFA), and leptin analysis. Throughout the weaner phase, Control pigs gained more (105±1g/d) than WR pigs (P<0.001). However, once pigs were switched to a high-Lys diet, WR pigs gained more (44±9kg/d) than Control pigs and utilised their feed more efficiently (P<0.001), and thus compensatory growth was observed. Pigs of both genotypes performed similarly throughout the weaner stage when fed the low-Lys diet, however, when fed the high-Lys diet, Hampshire pigs had a greater rate of gain compared to Large White pigs (308 vs. 296±8g/d). Throughout the experiment, Hampshire pigs ate more feed (P<0.001), gained more (P<0.001), and had a greater Lys intake (P<0.001) compared to Large White pigs. Lean meat percentage at slaughter was greater for the Large White pigs compared to Hampshire pigs (P<0.05). At 6 week of age NEFA concentrations were greater for Control pigs compared to WR pigs (P<0.05). Hampshire pigs on the WR treatment had lower BUN levels during the weaner period compared to Hampshire pigs on the Control treatment (P<0.10). In conclusion compensatory growth was observed in both genotypes. The fact that Hampshire pigs grew faster when fed a non-limiting diet but grew at a similar rate compared to Large White pigs when fed a limiting Lys diet indicates that limiting dietary Lys level rather than genotype determined growth performance.

Are compensatory live weight gains observed in pigs following lysine restriction during the weaner phase?

Despite a large amount of work on compensatory growth in pigs it continues to be poorly understood with many conflicting reports. The aim of this work was to conduct four similar trials using the same genotype of pig, facilities, feed and growth restriction period to determine whether it was possible to obtain consistent results using a constant trial set-up. A total of 576 pigs (Hampshire sire×(Large White×Landrace) dam) were used. Pigs were weaned onto trial at 26.8±0.11 (mean±SE) days of age at a mean weight of 8.1±0.07kg and remained on trial until slaughter, approximately 150.9±0.66 days of age at a mean weight of 98.4±0.65kg. In each of the four trials the restriction period was for 3 weeks immediately following weaning. Pigs received either a high (Control; 17.5g/kg) or a low (weaner restrict (WR); 8.0g/kg) lysine diet during these 3 weeks, all pigs then received a high lysine diet up until slaughter, 15.5 and 12.0g/kg of lysine for the grower and finisher diets respectively. Pigs from trial 1 ate (P<0.001) and gained (P<0.001) more throughout the weaner stage than all other trials. Growth performance was successfully reduced during the weaner phase. WR pigs grew more slowly (P<0.001) and less efficiently (P<0.001) than Control pigs. WR pigs from trial 1 demonstrated compensatory gains throughout the grower stage, growing 6% faster than Control pigs from trial 1 due to an improvement in feed efficiency (P<0.001). WR pigs from trial 2 demonstrated compensatory gains during the finisher stage, increasing their rate of gain by 7.0% compared to Control pigs from trial 2 again due to an improvement in feed efficiency (P<0.1). However previous lysine restriction did not result in compensatory growth in trials 3 and 4. WR pigs from trials 3 (P<0.05) and 4 (P<0.1) had a lower feed intake compared to Control pigs during the grower stage and an overall lower lysine intake throughout the trial (P<0.05; P<0.05). Although pigs from trials 1 and 2 demonstrated compensatory growth following a reduction in performance when dietary lysine levels as low as 8.0g/kg lysine were fed for a period of 3 weeks immediately post-weaning, pigs from experiments 3 and 4 did not, thus compensatory growth was not consistently observed.

Effect of dietary phosphorus and calcium level and phytase addition on performance, bone parameters, apparent nutrient digestibility, mineral and nitrogen utilization of weaner pigs and the subsequent effect on finisher pig bone parameters

Two experiments (Exp. 1 and Exp. 2), were conducted to investigate the effect of phosphorus (P) and phytase (PHY) addition on growth performance, coefficients of total tract apparent digestibility, and P, calcium (Ca) and nitrogen (N) utilization of weaner pigs from 11 to 30 kg body weight (BW) and the subsequent effect of early P and PHY nutrition in the finished pig (30–100 kg BW), when offered an adequate P and Ca diet. In Exp. 1, six diets were fed to ninety-six weaner pigs ( n = 8) to investigate the interaction of P and PHY on growth performance, bone parameters and faecal score. The six diets included three dietary levels of P (4.5, 5.5 and 6.4 g total (t)P/kg) and two concentrations of PHY (0 and 500 PHY units/kg) in a 3 × 2 factorial arrangement. Owing to the design of the experiment, as dietary P level increased, there was also an increase in dietary Ca level in order to maintain a dietary Ca to P ratio of 1.6:1. Bone samples were collected from 48 pigs (eight pigs per treatment) at the end of the weaner performance study (30 kg BW). The remaining 48 pigs were then offered a grower and finisher diet containing adequate P and Ca until they reached 100 kg BW. In Exp. 2, the coefficients of total tract apparent digestibility and P, Ca and N utilization experiment, twenty-four male pigs ( n = 4) were offered identical diets to that offered to weaner pigs in the performance study (Exp. 1). Weaner pigs were placed individually in metabolism crates for total but separate urine and faeces collection. The weaner pigs fed the PHY supplemented diets (PHY diets) had an improved feed conversion ratio (P<0.05) compared with those fed diets without PHY (non-PHY diets). Pigs offered the high P diet had a higher concentration of bone ash (P<0.05) than those offered the medium and low P diets at 30 kg BW. Pigs offered PHY diets (P<0.001) and the medium and high P diets (P<0.05) during the weaner stage had a higher bone ash concentration than pigs offered non-PHY diets and low P diets when slaughtered at 100 kg BW. In Exp. 2, pigs offered PHY diets had a higher (P<0.001) P digestibility and P retention than pigs offered non-PHY diets. In conclusion there is no advantage to feeding market pigs during the weaner stage tP levels greater than 5.5 g/kg. However, feeding levels of 6.4 g tP/kg during the weaner stage would be an advantage for swine producers aiming to maximise bone mineral concentrations at 100 kg BW.