E. Fàbrega

Effects of halothane gene and pre-slaughter treatment on meat quality and welfare from two pig crosses.

Pigs from crosses of a Piétrain (Pi) and a Large White×Piétrain (LwPi) heterozygous (Nn) boar lines with Landrace×Large White homozygous negative (NN) sows, were used to study the effect of halothane gene and pre-slaughter treatment on animal welfare and meat quality. A total of 83 gilts (47 NN and 36 Nn) were assigned to a long treatment (3 h 15 min transport and 12 h lairage) and 73 (39 NN and 34 Nn) to a short treatment (30 min transport and 2 h lairage). Heart rate was recorded throughout loading and transport. Blood samples were collected before loading, after transport, and at exsanguination to measure cortisol, creatine phospho-kinase (CPK) and lactate dehydrogenase (LDH). Carcasses were classified and commercial cutting was carried out. Meat quality was assessed on the Longissimus thoracis muscle by measuring electrical conductivity (PQM), colour (Minolta CR 200 and Japanese scale) and ultimate pH. Loin drip losses were assessed at 24 h. Halothane carriers showed a higher increase in cortisol levels after transport and exsanguination in the long treatment (P<0.05) as well as in LDH and CPK after exsanguination in the short treatment (P<0.05). In this treatment, halothane-free pigs recovered during lairage when comparing LDH and CPK increases after exsanguination to their increases after transport. No effect of the halothane gene on heart rate was observed. Pi sired pigs were leaner and had higher yields of leg and loin compared with LwPi sired pigs (P<0.001), but no differences in meat quality were observed between crosses. Halothane carriers had a higher estimated lean content (P<0.01) and shoulder and leg yields (P<0.01), but poorer meat quality than non-carriers (i.e. higher incidence of PSE meat, P<0.001). Although pre-slaughter treatment and halothane genotype did not significantly affect pHu, significantly higher L*, a* and b* values found in the short treatment and Nn individuals indicated paler meat. These results suggest that for improving meat quality and welfare the halothane gene should be removed from breeding schemes.

Effect of leg conformation on survivability of Duroc, Landrace, and Large White sows.

Sow longevity influences farm economy and can be considered an important indicator of animal welfare. Body features such as leg conformation can play a key role in sow longevity, although little is known about its effect on culling decisions. Within this context, longevity data from 587 Duroc, 239 Landrace, and 217 Large White sows were analyzed with special emphasis on the effect of leg conformation. Sow longevity was analyzed twice for each breed, testing the effect of a subjective overall score for leg conformation, or the presence or absence of 6 specific leg conformation defects. Each preliminary model also included a teat conformation score with 3 levels, farm or origin, backfat thickness at 6 mo of age, and 2 continuous sources of variation, namely the age at the first farrowing and the number of piglets born alive at each farrowing. Overall leg conformation score influenced (P < 0.01) sow longevity in Duroc, Landrace, and Large White sows, with a greater hazard ratio (HR) for poorly conformed sows (1.56, 2.16, and 1.79, respectively) than for well-conformed sows (0.32, 0.66, and 0.68, respectively). Abnormal hoof growth reduced survivability in Duroc (HR = 2.78; P < 0.001) and Landrace sows (HR = 1.88; P < 0.01); the presence of splayed feet (P < 0.05) or bumps and injuries (P < 0.001) increased the risk of culling in Duroc sows (HR = 2.08 and 3.57, respectively), whereas the incidence of straight pastern increased the HR in Large White sows (HR = 2.49; P < 0.01). In all 3 breeds, longevity decreased for plantigrade sows, with a greater HR in Duroc (HR = 3.38; P < 0.001) than in Landrace (HR = 1.53; P < 0.10) and Large White sows (HR = 1.73; P < 0.05). Teat conformation did not influence sow longevity (P > 0.10). Estimates of heritability for longevity in Duroc sows ranged from 0.05 to 0.07 depending on the algorithm applied. Leg conformation had a substantial effect on sow longevity, where an accurate removal of poorly leg-conformed candidate gilts before first mating could improve sow survival and reduce culling costs. These moderate estimates of heritability indicated that survivability of Duroc sows could be genetically improved by direct selection for leg conformation.

A comparison of halothane homozygous negative and positive pietrain sire lines in relation to carcass and meat quality, and welfare traits.

Barrows (n=164) and gilts (n=249) from crosses of a Pietrain homozygous halothane recessive (Pi nn) and two Pietrain homozygous dominant (Pi NN-a and Pi NN-b) sire lines with Landrace×Large White NN sows, were used to study the effect of terminal sire and pre-slaughter treatment on meat quality and animal welfare. The pigs from each of the two farms where they were finished were delivered to the abattoir in two batches differing in the pre-slaughter conditions. A total of 90 pigs (54 NN and 36 Nn) were assigned to a long pre-slaughter treatment (6 h transport and 14.5 h lairage) and 89 (57 NN and 33 Nn) to a short pre-slaughter treatment (4.5 h transport and 2.5 h lairage) in Farm 1, and 118 (65 NN and 53 Nn) to the long (7 h transport and 14 h lairage) and 114 (66 NN and 48 Nn) to the short pre-slaughter treatment (1.5 h transport and 2 h lairage) in Farm 2. In Farm 1, heart rate of 3 NN and 3 Nn gilts was recorded throughout loading and transport and blood samples from 5 NN and 5 Nn were collected before loading and after transport to measure cortisol, creatine phosphokinase (CPK) and lactate dehydrogenase (LDH). Carcasses were classified and commercial cutting was carried out. At 24 h, meat quality was assessed on the Longissimus thoracis muscle by measuring electrical conductivity (PQM), colour (Minolta CR 200 and Japanese scale), pHu and drip losses. Halothane carriers showed a higher mean heart rate and higher increase in CPK levels (P<0.05) after transport in the short pre-slaughter treatment than halothane free pigs. No effect was observed in cortisol or LDH values. Pi NN-a sired pigs had a higher live and carcass weight (P<0.001) and loin depth (P<0.05), but lower killing out percentage (P<0.01) and leg yield (P<0.01) compared with the progeny of the other two terminal sires. Gilts were leaner (P<0.001), had a higher killing out percentage (P<0.001) and higher yields of primal cuts (P<0.001) compared with barrows. Pi nn sired pigs had poorer meat quality (higher PQM values in both farms, P<0.01) than Pi NN-a sired pigs. Long pre-slaughter treatment resulted in darker meat (P<0.01) in both farms and in higher pHu (P<0.001) in Farm 1 than short pre-slaughter treatment. Conversely, pigs subjected to the short pre-slaughter treatment showed higher PQM values (P<0.01) in Farm 1 and higher PSE percentage (P<0.05) in both farms compared to the ones subjected to the long pre-slaughter treatment. These results suggest that Pietrain halothane free sire lines could produce similar results on carcass quality to halothane carriers, without compromising meat quality and welfare.

Differences in Open Field Behavior Between Heterozygous and Homozygous Negative Gilts for the RYR(1) Gene

A test widely used to assess fear and novelty responses in domestic species is the open field. The aim of this study was to investigate the effect of RYR(1) genotype on open field behavior in growing pigs. The study subjected 15 heterozygous (Nn) and 15 RYR(1)-free (NN) gilts of 19 weeks of age to 3 replicates of an open field test 2 days apart from each other. The study measured the number of grid lines crossed and defecation score in the test arena. There was a significant individual correlation among the 3 replicates of the test, both for number of grid lines crossed and defecation score (p < .05). RYR(1) genotype had a significant effect on number of grid lines crossed, with NN gilts showing more overall activity than Nn gilts (p < .05). The study observed no significant differences in defecation score between genotypes. This result suggests that the RYR(1) genotype may have an effect on the appraisal of novelty. Thus, it would be interesting to take this factor into account when using this methodology to assess fear responses in pigs and in interpreting the results with respect to welfare.

Feeding patterns, growth performance and carcass traits in group- housed growing-finishing pigs: the effect of terminal sire line, halothane genotype and age

The effects of terminal sire line, halothane genotype and age on feeding patterns and growth performance were studied in 208 castrated growing-finishing pigs distributed in two batches. In batch 1 (no. = 130), pigs came from crosses of NN Landrace × Large White sows with a Pietrain Nn (Pi-Nn) or a Large White ✕ Pietrain Nn terminal sire line (LwPi-Nn). In batch 2 (no. = 78), the same sows were used but crossed with three different terminal sire lines : a Pietrain nn (Pi-nn), and two Pietrain NN (Pi-NNa and Pi-NNb). Growth performance and feeding patterns of the progeny (Nn or NN for the halothane gene) were measured from 67 to 166 days of age. Pigs were housed in groups of 10 and 13 individuals in Batch 1 and 2, respectively, with a random mixed-breed and halothane genotype sample in each group (space allowance 1·3 m 2 per pig and 1·1 m 2 per pig, respectively). Feeding patterns were monitored with a computerized food intake recording system (IVOG ® -station) and every 3 weeks pigs were weighed and backfat and loin-muscle depth were ultrasonically recorded (PIGLOG ® ). Carcass quality was assessed with the Fat-o-Meater grading probe. In batch 1, halothane genotype did not have a significant effect on any of the feeding patterns recorded, but Nn individuals had a significantly higher body weight ( P < 0·05), loin-muscle depth ( P < 0·05) and lower backfat thickness ( P < 0·01) in the last measurement taken, 3/4 carcass loin depth ( P < 0·05) and lower carcass last rib backfat ( P < 0·05) than NN pigs. Terminal sire line had a significant effect on all feeding patterns recorded except for feeding rate, Pi-Nn sired pigs showing a significantly higher food intake per visit ( P < 0·05) and feeder occupation time per visit ( P < 0·05) and lower number of visits ( P < 0·001) compared with LwPi-Nn sired pigs which, in turn, showed significantly higher food intake per day ( P < 0·001) and feeder occupation time per day ( P < 0·01). Terminal sire also affected growth performance and body composition, Pi-Nn sired pigs having a significantly lower body weight ( P < 0·001) and backfat thickness ( P < 0·001) but higher killingout proportion and 3/4 loin depth ( P < 0·01) than LwPi-Nn sired pigs. In batch 2, Pi-NNb sired pigs showed a significantly lower food intake per day compared with the progeny of the other two terminal sires lines at some of the age measurements taken ( P < 0·05). The rest of the feeding patterns was not affected by terminal sire line. Body and carcass weights were also significantly lower ( P < 0·01) for Pi-NNb sired pigs, but their killing-out proportion was higher than Pi-NNa sired pigs. With regard to these variables, Pi-nn sired pigs held an intermediate position between the two NN terminal sire lines. In both batches, age was associated with a significant increase in food intake per visit and per day and feeding rate ( P < 0·001) and a decrease in feeder occupation time per visit and per day and frequency of visits to the feeder ( P < 0·001). Overall, the present results suggest differences between

Genetic background and phenotypic characterization over two farrowings of leg conformation defects in Landrace and Large White sows.

A Bayesian threshold animal model was applied to evaluate the prevalence over 2 farrowings and genetic background of overall leg conformation score and the presence or absence of 6 specific leg defects (abnormal hoof growth, splay footed, plantigradism, straight pasterns, sickle-hocked legs, and the presence of swelling or injuries) in purebred Landrace and Large White sows. Data sets contained phenotypic records from 2,477 and 1,550 Landrace and Large White females, respectively, at the end of the growing period. Leg conformation data from first and second farrowings were available for 223 and 191 Landrace sows and 213 and 193 Large White sows, respectively. Overall leg conformation deteriorated with age, with statistically relevant differences between females at the end of the growing period, first farrowing (FF), and second farrowing (SF). In a similar way, the prevalence of the 6 specific leg defects increased between the end of the growing period and FF (with the exception of straight pasterns in the Landrace population). Differences between FF and second farrowing were statistically relevant for hoof growth (highest posterior density regions at 95% did not overlap), plantigradism, sickle-hocked legs, and overall leg conformation score in Landrace and for sickle-hocked leg and overall leg conformation score in Large White. The statistical relevance of the genetic background was tested through the Bayes factor (BF) between the model with the additive genetic component and the model with 0 heritability (nonheritable). Heritability (h(2)) was discarded (BF < 1) for sickle-hocked leg in both breeds, whereas decisive evidence (BF > 100) of genetic background was obtained for overall leg conformation score in Landrace and Large White sows (h(2) = 0.27 and 0.38, respectively), hoof growth in both breeds (h(2) = 0.22 and 0.26, respectively), and plantigradism (h(2) = 0.34) and the presence of swelling or injuries in Landrace (h(2) = 0.27). Note that a BF > 100 implies that the model with infinitesimal genetic effects was more than 100 times more suitable than the model without genetic effects, a conclusive estimate within the Bayesian framework. The remaining traits (splay footed and straight pasterns) registered BF values ranging from 11.6 to 35.1 and h(2) values ranging from 0.09 to 0.19. These results indicated a moderate genetic determinism for leg conformation in Landrace and Large White sows.

Competing risk analyses of longevity in Duroc sows with a special emphasis on leg conformation.

A competing risk approach was used to evaluate the influence of several factors on culling risk for 587 Duroc sows. Three different analyses were performed according to whether sow failure was due to death during productive life (DE) or to one of two causes for voluntary culling: low productivity (LP) and low fertility (LF). Sow survival was analyzed by the Cox model. Year at first farrowing (batch effect) significantly affected sow survival in all three analyses (P < 0.05 for DE and P < 0.001 for LP and LF) whereas farm of origin accounted for relevant variation in the LP and LF analyses. LP culling increased with backfat thickness of more than 19 mm at the end of the growth period (P < 0.05), bad teat condition (P < 0.05) and reduced piglets born alive (P < 0.001). For the LF competing risk analysis, culling increased with age at first farrowing (P < 0.1). Special emphasis was placed on the influence of leg and teat conformation on sow survivability, although they did not affect sow failure due to DE (P > 0.1). The overall leg-conformation score significantly influenced sow longevity in LP (P < 0.001) and LF competing risk analyses (P < 0.001), showing a higher hazard ratio (HR) for poorly conformed sows (1.013 and 4.366, respectively) than for well-conformed sows (0.342 and 0.246, respectively). Survival decreased with the presence of abnormal hoof growth in LP and LF analyses (HR = 3.372 and 6.002, respectively; P < 0.001) and bumps or injuries to legs (HR = 4.172 and 5.839, respectively; P < 0.01). Plantigradism reduced sow survival in the LP analysis (P < 0.05), while sickle-hooked leg (P < 0.05) impaired sow survival in the fertility-specific analysis. Estimates of heritability for longevity related to LP culling ranged from 0.008 to 0.024 depending on the estimation procedure, whereas heritability values increased to between 0.017 and 0.083 in LF analysis. These analyses highlighted substantial discrepancies in the sources of variation and genetic background of sow longevity depending on the cause of failure. The estimated heritabilities suggested that direct genetic improvement for sow longevity seemed feasible, although only a small genetic progress was expected.

Effect of environmental enrichment and herbal compound supplementation on physiological stress indicators (chromogranin A, cortisol and tumour necrosis factor- α ) in growing pigs

Stress response induces physiological, behavioural, immunological and biochemical changes that directly affect health and well-being. Provision of environmental enrichment and herbal compounds may reduce stress in current commercial pig husbandry systems. The aim of this study was to evaluate the effect of providing different environmental enrichment materials (EE) and a herbal compound (HC) on physiological indicators of acute and chronic stress in growing pigs (salivary cortisol and chromogranin A (CgA), hair cortisol and tumour necrosis factor-α (TNF-α)). Salivary cortisol and CgA have been reported as biomarkers basically of acute stress, whereas hair cortisol and TNF-α have been more related to chronic stress. For this purpose, eight groups of seven pigs each (14 pigs/treatment, 56 pigs in total) were used: (a) two EE groups, (b) two groups supplemented with HC, (c) two groups provided both with EE and HC and (d) two control groups. Samples of hair, saliva and blood were taken to measure cortisol (in hair and saliva), CgA (in saliva) and TNF-α (in blood) at three different times: before starting the experiment (T0), and after 1 (T1) or 2 months (T2) of providing the materials and herbal compound. No differences were found at T0 in salivary or hair cortisol, CgA or TNF-α, whilst at T2, the control group showed significant increased concentrations of CgA and hair cortisol, when compared with the rest of the treatments (P<0.001). These differences were significant at T1 only for CgA (P<0.001). Furthermore, an overall correlation was reported between hair cortisol and salivary CgA (r=0.48, P<0.001). These results support that providing enrichment material or an herbal compound may reduce stress in growing pigs. Furthermore, the results support that hair cortisol and CgA may be proper non-invasive tools to detect stress, specially associated with factors of chronic exposure.

Analysis of cortisol in hair samples as an indicator of stress in pigs

ABSTRACT Detection of cortisol is one of the most widely used methods to assess stress in animals because it provides information about hypothalamic‐pituitary‐adrenal axis activity. The most common biological samples are plasma, saliva, urine, feces, milk, and hair. Hair cortisol analysis could be a good noninvasive procedure to detect chronic stress because cortisol is incorporated and stored inside growing hair. The aim of this study was to determine whether cortisol could be detected in pig hair and could serve as a proper chronic stress indicator. Hair samples from 2 regions (craniodorsal [D] and dorsolumbar [L]) of 20 crossbred entire male pigs were taken at 8 and 22 weeks of age. The pigs were subjected to a weekly remixing procedure. The mean cortisol level for the hair samples was 19.30 ± 0.63 pg/mg (range, 6.4‐43.88). Hair for second sampled day had higher cortisol values (P = 0.002) than hair from first sampled day. Furthermore, L region had higher values than D region at every age measurement (P < 0.001). Significant positive correlations were found between first sampled day and second sampled day in both region D (r = 0.442; P = 0.019) and region L (r = 0.523; P < 0.001). There were also correlations between both regions for first day (r = 0.595; P < 0.001) and second day (r = 0.523; P < 0.001). Thus, cortisol could be detected in pig hair. However, some methodological improvements and constraints were detected, and further studies are required before recommending its use as a chronic stress indicator.

Effect of Environmental Enrichment and Herbal Compounds-Supplemented Diet on Pig Carcass, Meat Quality Traits, and Consumers’ Acceptability and Preference

Simple Summary Interest in animal welfare has increased and been considered a relevant attribute for the concept of the ethical quality of pig products. The present study suggests that consumers would appreciate particular improvements on animal welfare such as providing environmental enrichment or herbal compounds. The provision of those welfare improvement strategies did not have a significant effect on technological carcass and meat quality parameters. However, the strategies used in this study that can increase animal welfare in production systems were valued by consumers. Abstract Animal welfare can be considered an ethical attribute of product quality, but consumers should appreciate its added value. The aim of this study was to evaluate consumer’s acceptability, preference, and the meat and carcass quality of pigs reared with two stress-reducing strategies: supplementation of an herbal compound (HC) containing Valeriana officinalis and Passiflora incarnata, and environmental enrichment (EE) by the provision of hemp ropes, sawdust, and rubber balls. A total of 56 pigs were divided in four treatments in two pens of seven pigs per treatment (2 × 2 factorial design). Meat and carcass quality were evaluated. Consumer’s acceptability and preference were analysed with a sensory test and a conjoint analysis in 110 consumers. Before slaughter, control pigs (no EE and no HC) presented lower live weight compared with other treatments (p = 0.0009). Although acceptance was the same for all of the treatments, consumers preferred systems aiming to increase pig welfare. The most important factor was production system, with a preference for those improving welfare, followed by feeding system, with a preference for those with natural herbs supplementation. Although price was the least important factor, a segment of consumers showed a clear preference for lower prices. These results suggest that welfare improvements could be appreciated by particular consumer segments.