Annalisa Scollo

Tail docking and the rearing of heavy pigs: The role played by gender and the presence of straw in the control of tail biting. Blood parameters, behaviour and skin lesions

This study evaluated whether the specific heavy pig rearing context allowed the fattening of undocked pigs without an outbreak of tail biting. At the same time, gender and straw availability (small amounts) were considered to understand their possible interactions with tail presence in the display of tail biting. A 2 × 2 × 2 factorial design was adopted to test the effects of these factors on blood parameters, behaviour and tail/ear lesions. Few interactions among factors were detected. Undocked pigs showed lower cortisol (P<0.02), lying behaviour (P<0.001), and higher risk of tail/ear biting (weeks 3 and 9), but lower risk of tail lesions (week 14). Straw increased the motivation for exploring (P<0.001), reduced serum haptoglobin (P<0.001) and the risk for tail biting (weeks 3, 9, 18) and ear biting (weeks 3, 9). Results highlight the importance of straw as an environmental enrichment and seem to indicate that fattening undocked heavy pigs is possible.

Continuous straw provision reduces prevalence of oesophago-gastric ulcer in pigs slaughtered at 170 kg (heavy pigs)

Adopting a 2 × 2 × 2 factorial design, this study evaluated whether continuous straw provision by racks, tail docking and gender (barrows vs. females) have an effect on the prevalence of lung lesions and oesophago-gastric ulcer (OGU) visually scored at slaughter in 635 Italian heavy pigs (169 ± 4 kg). The lung lesions were very low (72% of pigs with score 0), and were not significantly different among the experimental groups. Overall, OGU was diagnosed in 47% of the pigs. The consumption of small amounts of straw (70 g/day/pig) represented a protective factor against the onset of OGU (OR: 0.27). Barrows were more likely than females to have OGU (OR: 1.52), while no significant differences between docked and undocked pigs were detected. Nevertheless, the presence of straw acted as a protective factor particularly in undocked pigs (OR: 0.16), suggesting that in this group the absence of rooting material may have a stronger effect on welfare.

The Assessment of Facial Expressions in Piglets Undergoing Tail Docking and Castration: Toward the Development of the Piglet Grimace Scale

Many piglets are exposed to potentially painful husbandry procedures within the first week of life, including tail docking and castration, without the provision of either anesthesia or analgesia. The assessment methods used to evaluate pain experienced by piglets are often affected by low specificity and practical limitations, prompting the investigation of alternative methodologies. The assessment of changes in facial expression following a painful event has been successfully applied to several species. The objective of this pilot study was to evaluate the utility of a Grimace Scale applied to neonatal pigs to evaluate pain evoked by tail docking and castration. Eight female piglets, Sus scrofa domesticus (Landrace/Large White X synthetic sire line) underwent tail docking and 15 male piglets (75% Large White and 25% Belgian Landrace) were exposed to the castration procedure. Clear images of the faces of the piglets were collected immediately pre- and post-procedure. The images were used by experienced observers to identify facial action units (FAUs) which changed in individuals over this period, and a scoring scale was depicted in a training manual. A set of randomly selected images were then combined in a scorebook, which was evaluated after training by 30 scorers, blind to the treatment. The scale for most FAU was used with a high level of consistency across all observers. Tail docking induced a significant change (P < 0.05) in free moving piglets only in the “orbital tightening” FAU, whereas no change in any unit was observed in castrated piglets, which were restrained at the time of assessment. In this initial stage of development, orbital tightening seems to have the potential to be applied to investigate painful conditions in neonatal pigs. Nonetheless, more studies are needed to assess its full effectiveness and to evaluate the influence of possible confounds (e.g., handling stress) on the observed changes in FAUs.

Can novel methods be useful for pain assessment of castrated piglets

Given that surgical castration is a painful practice performed on millions of pigs every year, a need to identify novel reliable pain assessment tools exists in order to test anaesthetic and analgesic protocols that may reduce related pain. Two treatments were considered: handling (H) and surgical castration (C). Physiological (cortisol, lactate, glycaemia, rectal and eye temperature) and behavioural variables (latency to move after treatment and alterations in posture and walking) were analysed. Cortisol showed the greatest level in C piglets within 20 min after the surgical procedure and a positive correlation with glucose concentration. Eye temperature was higher in C piglets, and the same difference was detected for rectal temperature 3 h after castration. Behavioural parameters revealed that C piglets had longer latency to move and a higher percentage of them showed alterations in posture and walking. Results of this study showed that, in castrated piglets behavioural and physiological alterations occur mainly in the first 3 h from treatment. Latency to move, alterations in posture and walking, and eye temperature appear to give additional and useful information in piglet pain assessment. However, differently from the behavioural parameters considered, eye temperature involves several manipulations of the animals and a long process to acquire the data.

Frequency of tail lesions and risk factors for tail biting in heavy pig production from weaning to 170 kg live weight.

Tail biting lesions have a negative effect on both the welfare of pigs and on the revenue of the pig farm. Due to the multifactorial nature of this abnormal behaviour and its sporadic onset, an epidemiological approach was adopted to identify the management and housing factors influencing the occurrence of tail biting and the frequency of bitten pigs in the weaning and fattening phases up to 170 kg live weight in heavy pig production. Data were collected from a sample of 67 commercial pig farms via an on-farm visit and a questionnaire to the farmer. Data collected included general farm information, hygiene and herd health, prevention, management, climate control, feeding and production traits. In the weaning phase, the occurrence of tail biting was increased by a factor of 16.64 for tipped vs. short-docked tails, by a factor of 68.09 when the observer detected poor air quality, and by a factor of 14.44 when the feeding time was variable. In fattening pigs, a high stocking density increased the risk of tail biting by a factor of 18.00. The frequency of lesions in weaners was greater in pigs with tipped tails (0.29 vs. 0.03%; P = 0.034), whereas in fatteners the frequency of lesions was greater when drinkers were not present in the lying area (0.71 vs. 0.05%; P = 0.009) and when air turnover was not detected in the barn (0.70 vs. 0.07%; P = 0.005). There was also a trend for increased tail biting when the stocking density was high (1.06 vs. 0.33%; P = 0.057). Many of the risk factors that emerged for heavy pigs in the present study could be easily managed to reduce the risk of tail biting and the frequency of tail lesions through the systematic evaluation and control of stocking density, climate, and feed and water management.

A cross-sectional study for predicting tail biting risk in pig farms using Classification and Regression Tree Analysis

Tail biting in pigs has been an identified behavioural, welfare and economic problem for decades, and requires appropriate but sometimes difficult on-farm interventions. The aim of the paper is to introduce the Classification and Regression Tree (CRT) methodologies to develop a tool for prevention of acute tail biting lesions in pigs on-farm. A sample of 60 commercial farms rearing heavy pigs were involved; an on-farm visit and an interview with the farmer collected data on general management, herd health, disease prevention, climate control, feeding and production traits. Results suggest a value for the CRT analysis in managing the risk factors behind tail biting on a farm-specific level, showing 86.7% sensitivity for the Classification Tree and a correlation of 0.7 between observed and predicted prevalence of tail biting obtained with the Regression Tree. CRT analysis showed five main variables (stocking density, ammonia levels, number of pigs per stockman, type of floor and timeliness in feed supply) as critical predictors of acute tail biting lesions, which demonstrate different importance in different farms subgroups. The model might have reliable and practical applications for the support and implementation of tail biting prevention interventions, especially in case of subgroups of pigs with higher risk, helping farmers and veterinarians to assess the risk in their own farm and to manage their predisposing variables in order to reduce acute tail biting lesions.

Prevalence and risk factors for gastric ulceration in pigs slaughtered at 170 kg

Oesophago-gastric ulcers (OGU) are a production and welfare problem in pigs. Stomach condition was scored for 22 551 pigs in 228 batches over a 7-month period at an abattoir in Italy processing heavy pigs for ham production. Mild or severe ulceration was observed in 20.7% of pigs, of which 13% had scar tissue. Variation between batches was high (0% to 36% prevalence of severe ulcers) and showed a significant effect of farm of origin (P<0.001). Overnight lairage increased the prevalence of mild ulcers (P<0.001), but not severe or scarred ulcers. Scarred ulcers increased in the hottest summer months. Prevalence of ulcers showed only few and weak correlations at batch level with pathologies of the pleura, lungs and liver, but a strong correlation with on-farm mortality of the batch. Analysis of farm risk factors for OGU was assessed by questionnaire with a response rate of 17% of farms. Risk factors retained in a multivariable model included a protective effect of anthelmintic treatment (risk ratio (RR)=5.1, P=0.03), increased risk in farms using Mycoplasma vaccination (RR=5.6, P=0.04) and a tendency for association with type of flooring (P=0.06). Univariable analyses also highlighted possible influences of other stress-inducing factors including lack of enrichment objects and mixing of pigs during fattening, suggesting that the role of on-farm stressors merits further investigation. It is concluded that abattoir screening of OGU in future programmes for the assessment of well-being on farm should encompass only severe lesions and scarring, and results be returned to farmers to facilitate improvement of production and welfare.

Benchmarking of pluck lesions at slaughter as a health monitoring tool for pigs slaughtered at 170 kg (heavy pigs)

Abattoir post-mortem inspections offer a useful tool for the development and monitoring of animal health plans and a source of data for epidemiological investigation. The aim of the present work was to develop an abattoir benchmarking system which provides feedback on the prevalence and severity of lesions of the pluck (lung, pleura and liver) in batches of pigs to inform individual producers and their veterinarians of the occurrence of pathological conditions affecting their herds. The weekly collection of data throughout a year (from September 2014 to September 2015) supported the further aim of providing benchmark values for the prevalence of lesions and their seasonality in Italian heavy pig production. Finally, correlations and redundancies among different lesions were evaluated. In total, 727 batches of heavy pigs (around 165kg live weight and 9 months of age) derived from 272 intensive commercial farms located in Northern Italy were monitored. Within each batch, an average number of 100 plucks was individually scored, assigning a value for lesions of lungs (0-24), pleura (0-4) and liver (1-3). Presence of lung scars, abscesses, consolidations, lobular/chessboard pattern lesions and pleural sequestra was also recorded. Statistical analysis showed a strong farm effect (36-68% of variation depending of the lesion) and a seasonal effect on all lesions. Winter showed the lowest percentage of severe lung and pleural lesions (P<0.001 and P=0.005), whereas lung scars from older lesions (P=0.003), as well as severe hepatic lesions (P<0.001), were reduced in autumn. In order to allow effective benchmarking of each farm in a determined health class, scores for each quartile of the population are reported. Whilst such a benchmarking scheme provides useful data for herd health management, challenges of repeatability of scoring and cost of implementation need to be overcome.

Pain alleviation during castration of piglets: a comparative study of different farm options.

Pain alleviation associated with castration of piglets is an important welfare issue. The present study compares the effect of different approaches and products suitable for farmer use, with the aim to alleviate pain due to castration in piglets. A randomized within-litter design, with 28 replicate litters, compared 7 treatments: handling () restraint of the piglet and manipulation of the scrotum, castration without pain relief (), 2 treatments (, ) with different concentrations of tetracaine (2 and 6%) applied topically 10 min before and immediately post-surgery, and 3 treatments with i.m. injection of different nonsteroidal anti-inflammatory drugs () 10 min prior to surgery (-meloxicam, -ketoprofen, -tolfenamic acid). Efficacy of pain relief was assessed during a 300 min period after castration by serum cortisol, behavior (walking, lying, suckling, in the nest, isolated and pain related: tremors, rubbing the rear, hunching, wagging of the tail), facial expression and scrotal skin pressure sensitivity. C pigs had greater serum cortisol concentration than all other groups at 60 min post-surgery ( < 0.001), while H pigs had lower concentrations than pigs given topical anesthesia ( < 0.001) though not injected analgesia. No treatment differences were significant at 180 min, but at 300 min cortisol concentration was greater in T2 and T6 piglets than those given NSAIDs ( = 0.03). These treatment differences were mirrored by the pressure sensitivity of the scrotum; in comparison with C piglets, those given NSAIDs showed a reduced sensitivity ( 0.003) but those given local anesthesia did not ( = 0.15). C pigs showed increased frequency of pain-related behavior in the first 30 min in comparison with all other treatments, more time isolated than H or NSAID treatments, and more time standing inactive than H or K treatments. No behavioral differences were apparent after 60 min. No differences in facial expressions were observed among treatments. In conclusion, on-farm methods for pain relief can provide some, though not complete, pain alleviation in the hours after castration. The use of topical anesthesia gave only minor benefit in comparison to NSAID agents injected prior to castration. Since the main differences in indicators of pain between positive and negative controls were observed within the first h after castration, it is important to select drugs that act quickly after administration to facilitate practical processing schedules on farm.

Effects of three different designed farrowing crates on neonatal piglets crushing: preliminary study

Abstract In swine production, the economic gain in the farrowing room corresponds to the number of weaned piglets/sow per year. Pre-weaning mortality is at least 11–13% of total losses within one herd, considering a previous 7–8% of the stillbirths. Piglet crushing by the sow contributes significantly to the overall piglet mortality. It is caused by multiple factors related to the sow, the piglet and due to modern swine husbandry along the last 50 years. This study aimed to compare three different designs of farrowing crates during the first three days of life in relation to piglet-crushing mortality in intensive herd. One hundred fifty-eight sows with spontaneous deliveries were housed in the following farrowing crates groups: group A (n = 51) farrowing within conventional crates, group B (n = 47) farrowing within the slide cage and group C (n = 60) in the up and down designed, for a total of 2487 live born piglets. In the first three days of life, group C reported the lower crushing mortality rate (0.54%), while groups B and A reported 2.37% and 5.46%, respectively. The comparison between the group C value compared with group A values (p<.001; Chi-square = 36.90) and B (p = .003; Chi-square = 8.81) were statistically significant. In conclusion, the approach to create more space for both mother and litter within an acceptable size of farrowing crates (slide cage and up & down designed) allowed a significant reduction in mortality crushing rate of the piglets during the first three days of life.