Larger Groups for Grower-Finisher Pigs: Feeding and Social Behaviours and Impacts on Social Stress.

Posted in: Prairie Swine Centre by admin on January 1, 2006 | No Comments

Most studies on feeding and social behaviours of pigs have been conducted on groups of fewer than 40 pigs/group. However, these group sizes are much smaller than some that are now used in some commercial operations (100-1000 pigs/group) in North America and elsewhere. The social dynamics of feeding and other behavioural activities of pigs in large social groups are not well understood and the competition for and the utilization of important resources such as feeders by pigs in larger social groups is therefore unclear. The present study was conducted to gain a better understanding of feeding and other behavioural activities and the impacts of larger social groups on social stress in grower-finisher pigs.

To address this question, two blocks, which consisted two group-size treatments, 18 (Small Group) and 108 (Large Group) grower-finisher pigs per pen, were carried out. Each block, which lasted 10 weeks in duration, consisted of two pens of Large Group and four pens of Small Group size. A total of five hundred seventy six barrows and gilts (Pig Improvement Canada) were used in the experiment at the PSC Elstow facility. The animals were weaned at approximately 18-day of age, were then held in nurseries for eight weeks, before being used in the experiment. The ratio of barrows to gilts was kept constant (1:1) between the two group sizes and the average starting weight of pigs was 34.6 kg ± 4.1 kg (S.D). Pigs were housed on fully-slatted floors with floor space allowance per pig of 0.76m2.

Wet/dry feeders supplied feed and water to the animals, with a pig to feeder space ratio of 9 to 1. Feeders were spread equidistantly along the central line in large groups with four feeder holes per feeder location. This maintained an equal distribution of feeders within the large group, giving an equal opportunity for all the pigs to access the feeders without any difficulty.

The individual pig feeding behaviour and group feeding patterns were studied during weeks 1, 5, 7 and 10 of the grower-finisher cycle. In addition, other behavioural activities such as percentage of time spent on eating/drinking, resting (lying) and standing/walking and diurnal patterns of these activities of pigs in both large and small groups were studied during weeks 2, 5 and 10 following re-grouping.

To evaluate the group size effect on social stress, salivary cortisol levels were measured periodically throughout the grower-finisher cycle i.e. during weeks 1, 2, 5 and 10. In addition, morphological parameters of the adrenal glands were measured at the end of grower finisher cycle to understand any effects of chronic stress on pigs that were formed into larger groups.

The pigs in large groups had more bouts of feeding (35 vs. 25, P<0.05) and the feeding bouts were shorter in duration (232 vs. 301 sec, P<0.05) during day 3 following re-grouping. However, no differences in number of feeding bouts and bout lengths were found during weeks 5, 7 and 10. More importantly, we found that the percentage of pigs queuing at the feeders to be high in larger groups than in smaller groups during day 3 (0.90 vs. 0.59, %, P <0.05). This trend of higher percentage of queuing at feeders were also apparent during day 6 following re-grouping (0.79 vs. 0.60, %, for large and small groups, P=0.08) but not thereafter. There were similar 24 hr group feeding patterns in pigs of both SG and LG during weeks 1, 5, 7 and 10 (Figure 1). Furthermore, the average percentage of feeder spaces occupied (mean day 3 and 6 and week 5, 7 and 10) was also similar between the two group sizes (55.7 vs. 56.2, %, for large and small groups). The average times spent on eating/drinking (5.2 vs. 5.2 %, for small and large groups), standing/walking (5.1 vs. 5.4 %, for small and large groups) and resting (89.6 vs. 89.3 %, for small and large groups) did not differ between the two group sizes. Furthermore, the diurnal patterns of these activities were also not affected by the large groups. One main concern of large group sizes for pigs is the potential for increased social stressors. Interestingly however in our study, during the entire 10 wk experimental period, pigs in larger groups did not demonstrate any short-term (acute) or long-term (chronic) responses of social stress (Table 1). Therefore, it was apparent that the pigs had not gone through any adverse social stressors by living in larger groups.

The impact of piglet birth weight on subsequent growout performance and carcass quality

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SUMMARY
Increased litter size resulted in decreased average birth weight, but how no effect on body weight variability at birth or later in life. Carcass quality was unaffected by litter size.

INTRODUCTION
Average litter size born alive in Canada has increased from 10.4 to 11.2 piglets in the last 5 years and continuing improvement is expected. Increased litter size results in a reduced mean birth weight. Recent analysis (Patience, unpublished data) showed that increasing litter size by 1 pig, reduced average birth weight by 100 g and doubled the proportion of piglets with a birth weight below 800 g.

Muscles contain primary and secondary fibres. One consequence of reduced birth weight are changes in the proportions of these fibre types in the muscles. The effect of this on the adult muscle composition and subsequent eating quality of the meat is not known.

The objective of this experiment was to determine if there is a relationship among birth weight and post-weaning growth performance on carcass quality, muscle histology and subsequent eating quality. Secondly, we wanted to determine if increased litter size was associated with increased variability of piglet weight at birth and during later life. The muscle histology and eating quality results will be presented in a later report.

MATERIALS AND METHODS
All farrowings were attended during a 5 week period at PSC Elstow. At the time of farrowing, each live-borne piglet was identified individually, weighed and then re-weighed on the day of weaning, 5 weeks post-weaning, at nursery exit, at first pull, and at the time of marketing.. The number of mummies and stillborn piglets were also recorded, but not weighed and not included in the birth order. Management followed normal barn protocols.

RESULTS AND DISCUSSION
Litter size. Data was collected from 98 liters and 1114 piglets (Table 1). Litters were divided into “small” (3 to 10 piglets born alive), “medium” (11 to 13 born alive) and “large”, (14 to 19 born alive). Interestingly, 91% of the total born were born alive in the small and medium groups, while greater than 98 % of those born in the large litters were born alive. The proportion of pigs weaned of those born alive was about 85% for all groups.
Average birth weight was 1.59, 1.41 and 1.35 kg for the small, medium and large groups, respectively (Table 1). The standard deviation (SD) of birth weight was very similar between groups, 0.30 to 0.32 kg, and therefore the coefficient of variation (CV; SD/mean * 100) was slightly less for the large litters.
Weaning weights. Average weaning weight was 6.55 kg, and ranged from 1.55 kg to 10.7 kg. The average SD for weaning weight was 1.45 kg, which is similar to the SD for the “large” litter group. The SD for the “small” litter groups was slightly higher, 1.59, and therefore the CV for weaning weight was similar among groups. The 5 and 7 week weights show a similar trend. Average weights were similar between groups, and the SD was actually slightly lower for the “large” litter groups, resulting in a similar CV between groups.
Market Data. Dressing weight was approximately 94.30 kg, and was similar between litter size groups, as was the SD and therefore the CV (Table 2). The lean yield, loin area, and mm of fat varied more within a litter group than between.

CONCLUSIONS
As expected, increased litter size, results in decreased average birth weight, however, it was suprising to observe that larger litters does not result in increased body weight variaiblity.

ACKNOWLEDGEMENTS
Strategic funding provided by Sask Pork, Alberta Pork, Manitoba Pork Council and Saskatchewan Agriculture and Food Development Fund. Specific funding for this project from the Alberta Industry Livestock Development Fund,m Ltd and PIC are gratefully acknowledged.

Impact of swine sulphur intake from drinking water on odour and gaseous emissions and manure nutrients

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Effect of meat appearance on consumer preferences for pork chops in Greece and Cyprus

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The intensity of pig production as well as the quality of pork meat has recently attracted consumer concern, which is manifested through their attitude towards pork (Bryhni et al., 2002; Ngapo, Martin, & Dransfield, 2002; Ngapo et al., 2004a). Today, besides concerns about production methods, pork quality is a contentious issue as a consequence of the absence of a single common definition and the fact that quality has evolved further from just implying lean yield percentage and back fat thickness. For example, quality now refers to all or some of the following: (i) carcass characteristics and composition, such as carcass uniformity and consistency, lean yield and fat, (ii) meat characteristics such as colour, marbling, pH, PSE (pale, soft and exudative) score, DFD (dark, firm and dry) score, (iii) eating quality characteristics including tenderness, juiciness and flavour, (iv) processing and retailing characteristics, such as drip and cook losses as well as shelf life, and (v) nutritional characteristics such as protein, vitamin and mineral contents (Bredahl, Grunert, & Fertin, 1998; Grunert, Bredahl, & Brunsø, 2004). Appearance has a great influence on how meat, including pork, is valued by the consumer. However, appearance quality dimensions cannot be easily evaluated at the point of purchase because the views on quality are based on a form of conditioning where consumers associate available cues with the quality of the product. The notion is that quality cues can be intrinsic or extrinsic (Olson, 1978). Intrinsic quality cues are part of the physical product such as colour or fat content (Bredahl et al., 1998; Bryhni et al., 2002; Hurling & Shepherd, 2003; Ngapo, Martin, & Dransfield, 2004b). Extrinsic quality cues are everything else that is related to the product or its production process, such as price and packaging (Cardello, 1995; Meiselman, Johnson, Reeve, & Crouch, 2000; Verbeke & Viaene, 2000). The effect of meat appearance on consumer’s preferences for pork chops was assessed using images manipulated for appearance characteristics. Data was collected from 412 consumers in Greece and Cyprus. Consumers were asked for their preference for pork chops from a book of computer-modified images and then completed a questionnaire of socio-demographic information, including eating and purchasing behaviour. Consumers under the age of 35 years showed preferences for dark red, lean pork, while consumers aged 35 years and older preferred either dark or light red pork. Gender appeared to be an important selection factor as men showed an increased preference for dark red pork while women preferred the light red. Consumers who stated that they like pork for its taste (91%) preferred either dark or light red pork chops while those who like pork for reasons other than taste preferred dark red, lean pork. Urban consumers preferred light red, fatty pork chops while the rural consumers preferred the dark red pork chops.

Le système d’évacuation du lisier muni d’une raclette réduit les niveaux de sulfure d’hydrogène dans les porcheries

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RÉSUMÉ – Un système d’évacuation du lisier muni d’une raclette a été évalué pour mesurer son efficacité à réduire les risques d’exposition au sulfure d’hydrogène (H2S) pour les travailleurs de porcherie et les porcs. L’évaluation a été faite en comparant les niveaux de gaz dans deux salles d’engraissement identiques dont une était munie d’un système à raclette (Raclette) et l’autre (Contrôle), considérée comme typique, était équipée d’un système conventionnel de gestion du lisier avec dalot et bouchon pour contrôler l’écoulement. Les concentrations de H2S dans la salle Raclette étaient significativement inférieures par 90% comparativement à celles de la salle Contrôle (p<0.05). Les émissions d’ammoniac n’étaient pas significativement affectées par le type de système d’évacuation du lisier mais avaient tendance à augmenter au cours des 4-5 semaines d’évaluation de chaque essai. Considérant la nature très variable liée à la production de H2S et à son émission à l’intérieur d’une salle, une attention particulière devrait toujours être portée à la vidange des dalots. INTRODUCTION – Une étude réalisée au PSCI a démontré que les travailleurs de porcherie risquent d’être exposés au H2S lors de la réalisation des tâches liées à l’évacuation du lisier emmagasiné dans les salles de production comme lorsque les bouchons des dalots sont tirés pour drainer le lisier. La réglementation en santé et sécurité au travail stipule qu’un travailleur ne peut être exposé à une TLV-TWA (concentration moyenne pondérée dans le temps pour une période de 8-h) de plus de 10 ppm ou à une TLV-STEL (concentration moyenne pondérée dans le temps pour période de 15min) plus de 15 ppm. Des 119 évènements de vidange de dalot par tire du bouchon réalisés dans différentes sections de différentes porcheries, 29% d’entres eux ont généré des pics de concentration supérieurs à 100 ppm et 48% ont générés des valeurs de TLV-STEL plus élevées que la limite recommandée de 15 ppm et ce au niveau des travailleurs. Comme un entreposage prolongé du lisier peut contribuer aux processus de dégradation anaérobique qui entraîner la production de H2S, un système de gestion du lisier qui permet une évacuation plus fréquente et complète du lisier des salles de production peut potentiellement réduire la production de H2S. Par conséquent, le but de cette étude était d’évaluer l’efficacité d’un système à raclette d’évacuation du lisier pour réduire les risques d’exposition au H2S pour les travailleurs de porcherie ainsi que pour les animaux. DISPOSITIF EXPÉRIENTAL – Deux salles d’engraissement identiques situées au PSCI ont été utilisées pour cette étude. Ces chambres contenaient chacune 70 porcs ; ces animaux avaient un poids moyen de départ de 21,5 kg et sont demeurés dans les salles durant 12 semaines pour chaque essai. Un système d’évacuation de lisier à raclette (Figure 1) a été installé dans une salle (Raclette). Une gestion normale de l’autre salle (Contrôle) a été faite, permettant au lisier de s’accumuler dans les dalots, suivi par la vidange de ceux-ci (écoulement suivant la tire du bouchon) qui était réalisée selon un horaire prédéterminé. La qualité de l’air et les concentrations de H2S dans les deux salles ont été mesurées durant quatre cycles de production (essais). Deux moniteurs de H2S (modèle Pac III, muni de senseur XS EC 1000 ppm H2S, Draeger, Lübeck, Germany) ont été installés dans chaque salle à environ 1 m au-dessus du plancher : un au-dessus du dalot à mi-largeur de l’enclos et l’autre directement au-dessus de la sortie d’écoulement où se situe le bouchon. Les concentrations d’ammoniac ont été mesurées aux entrées d’air ainsi qu’aux sorties de ventilation des deux salles à l’aide d’un analyseur d’ammoniac (modèle Chillgard RT, MSA Canada, Edmonton, AB). RÉSULTATS ET DISCUSSION – Si on considère les lectures moyennes obtenues des deux endroits échantillonnés, la salle Raclette présentait des sommets de concentrations de H2S significativement plus bas que ceux obtenus dans la salle Contrôle (p<0.05), correspondant en moyenne à une réduction d’environ 90% (Tableau 1). De manière comparable, le système à raclette a permis de réduire de manière significative les concentrations TVL-TWA par environ 96% en moyenne (p<0.05). Une évacuation plus fréquente du lisier en utilisant le système à raclette n’a pas eu d’effet sur la concentration en ammoniac mesurée aux sorties de ventilation des salles (p<0.10) (Figure 2). En moyenne, 35,6% plus d’ammoniac était émis de la salle Raclette comparativement à la salle Contrôle, indiquant ainsi que ce système d’évacuation du lisier tend à augmenter les émissions de la salle (p<0.10). Les émissions moyennes hebdomadaires d’ammoniac augmentaient aussi de manière significative (p<0.001) avec la progression de chaque essai ; ceci étant dû à une augmentation de la production de lisier et aux débits de ventilation requis pour évacuer la chaleur et l’humidité produites qui elles aussi augmentaient. CONCLUSION – Dans l’ensemble, les résultats ont démontré l’efficacité du système à raclette à réduire l’exposition des travailleurs de porcherie au H2S et ce avec un impact marginal sur la production d’ammoniac. Si l’on considère les coûts d’installation et de fonctionnement associés à cette étude, il en coûterait environ 2$ et 3$ par porc vendu pour la construction et le fonctionnement d’un système à raclette dans une nouvelle porcherie ou une porcherie existante, respectivement. Cependant, ce coût ne tient pas compte des bénéfices associés à une amélioration de la sécurité des travailleurs. REMERCIEMENTS – Financement stratégique provenant de Sask Pork, Alberta Pork, Manitoba pork Council et Saskatchewan Agriculture and Food Agricultural Development Fund. Support technique : Shala Christianson, Robert Fengler et Karen Stewart.

La séparation du fumier/lisier en utilisant un système de tapis roulant : l’impact sur les émissions d’odeurs et de gaz

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Un nouveau système d’hébergement pour les porcs en croissance-finition qui incorpore un système de tapis roulant (TR) pour séparer les fèces de l’urine au niveau de l’enclos a été développé. Des tests comparatifs ont démontré que la performance et le bien-être des animaux n’ont pas été affectés de façon négative par l’usage du système d’enclos TR. Le système était efficace pour isoler la majorité du phosphore dans une phase solide de masse peu élevée. Les tendances générales chez les taux d’émissions de gaz ont démontré que le concept de design d’enclos TR peut aider à diminuer le taux d’émission de dioxyde de carbone. Aucun impact important n’a été observé pour l’ammoniac et les émissions d’odeurs. Introduction – Des inquiétudes environnementales venant de la manipulation de grandes quantités de lisier provenant de la production animale ont mené à l’exploration de nouvelles stratégies innovatrices qui ont pour but de gérer le fumier/lisier de façon économique et respectueuse de l’environnement. Ce projet de recherche a permis d’explorer un nouveau concept de système d’enclos dans lequel la section en caillebotis de l’enclos a été remplacée par un tapis roulant (TR) incliné pour séparer les fèces et l’urine au niveau de l’enclos. Ce projet a été implanté en deux phases : La Phase 1, qui a été effectuée aux installations de l’IRDA au Québec, impliquait le développement du concept de design d’enclos avec le système TR et une évaluation de l’efficacité de la séparation des composantes liquides et solides. Le but principal des essais de la Phase 2, qui ont été effectués au Prairie Swine Centre, était de comparer les émissions odorantes et gazeuses d’une salle équipé avec le système TR (Figure 1) avec celles d’une autre salle avec un système de gestion de fumier conventionnel (caillebotis et dalot sous le caillebotis). Résultats et discussion – Les résultats de quatre essais menés à l’IRDA ont démontré que le système TR a été très efficace pour isoler la majorité du phosphore dans une phase solide de faible masse; de 76 à 81% du phosphore excrété par les porcs dans la salle TR a été isolé à l’intérieur de la phase d’excréments solide. Les résultats ont aussi démontré que de 39 à 48% de l’azote total était dans l’urine alors que les fèces contenaient presque la même concentration d’azote (de 40 à 45% d’azote total). Le contenu d’azote ammoniac total (TAN) dans l’urine variait de 75 à 79%, ce qui correspond au niveau attendu car le TAN provient principalement de la dégradation de l’urée produite dans l’urine. D’une perspective de gestion de phosphore, le nouveau concept de design d’enclos a démontré le pouvoir potentiel d’isoler approximativement 80% du phosphore en phase solide représentant 20% de la masse totale de fumier/lisier. Des observations faites ont démontré que les porcs hébergés dans le système équipé avec le système TR étaient plus fréquemment couchés dans la section de repos que les porcs hébergés dans l’enclos conventionnel (groupe contrôle). Ils avaient aussi tendance à utiliser moins fréquemment la section TR (zone ciblée pour recevoir les déjections) pour se coucher que les porcs dans l’enclos contrôles, ce qui suggère que le système TR pourrait possiblement promouvoir la propreté dans l’enclos. La fréquence des épisodes de consommation de nourriture et d’eau n’a pas été affectée par le système TR, ce qui est en accord avec les données de consommation et de conversion alimentaire. Les tendances générales des concentrations de gaz (e.g., ammoniac (NH3) et dioxyde de carbone (CO2)) mesurées dans les essais effectués au Prairie Swine Centre et à l’IRDA ont indiqué que le design d’enclos TR a contribué à la réduction des niveaux de ces gaz. Les valeurs de concentration d’odeur des échantillons pris des salles conventionnelles et TR étaient très variables, alors la comparaison statistique des valeurs d’odeur des deux chambres n’a pas montré de différence signifiante (p>0,05). En ce qui concerne les émissions de gaz, le concept de design d’enclos TR peut aider à réduire le taux d’émissions de gaz spécifiques (e.g., CO2) en comparaison avec la salle conventionnelle (Tableau 1). Aucun impact significatif du système n’a été observé pour les émissions d’autres gaz (e.g., NH3) et d’odeur. Conclusions 1 – Le concept de design d’enclos TR s’est avéré efficace pour séparer les composantes liquides et solides du fumier/lisier de façon continue, ce qui permet une gestion et manipulation plus efficace des éléments fertilisants (en particulier le phosphore et l’azote) dans les composantes séparées. 2. La performance et le bien-être des animaux n’ont pas été affectés négativement par l’usage du design d’enclos TR. 3. Les tendances générales des concentrations de gaz (ammoniac et dioxyde de carbone) observés indiquent que le design d’enclos TR a contribué à la réduction des niveaux de ces gaz. 4. Les valeurs de concentration d’odeur pour les échantillons pris des salles TR et conventionnelle étaient très variables, par conséquent la comparaison statistique des valeurs d’odeur des deux chambres n’a montré aucune différence signifiante. 5. Les tendances générales des taux d’émissions de gaz ont démontré que le concept de design d’enclos TR peut aider à réduire le taux d’émission du dioxyde de carbone comparativement au système de salle conventionnelle. Cependant, le système TR n’a pas eu d’impact significatif sur les émissions d’ammoniac et d’odeur. Des recherches approfondies pour mieux évaluer cette technologie peuvent être faites avec un contrôle accrus des niveaux de contaminants dans l’air alimentant les salles et des techniques améliorées pour mesurer l’odeur. Les expériences avec le concept de design d’enclos TR ont aussi révélé des secteurs potentiels pour pousser le travail et optimiser le système et réaliser des bénéfices importants de l’usage d’un tel système en plus de ceux déjà mentionnés. En séparant le lisier en deux parties, le système TR peut aider à réduire le danger associé à l’exposition au H2S dans les élevages porcins. Un système TR optimisé peut être potentiellement incorporé dans la construction d’une porcherie à fosse profonde permettant l’entreposage à long terme des composantes séparées, limitant ainsi les dangers typiques associés aux niveaux de H2S potentiellement élevés associés avec les porcheries à fosse profonde conventionnelles. Remerciements – Sask Pork, Alberta Pork, Manitoba Pork Council et Saskatchewan Agriculture and Food pour leurs subventions stratégiques. Ce projet a été subventionné par l’Association du Ciment du Canada et l’Institut de Recherche et de Développement en Agroenvironnement. Nous tenons à remercier Garth MacDonald, Scott Cortus, Robert Fengler, et Erin Cortus pour leur assistance technique.

2006 Michigan Swine Business Analysis Summary

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This report summarizes the financial and production records of 14 Michigan swine farms. To be included, the farms must have produced at least 50 percent of gross cash farm income from one or a combination of fat hogs, feeder pigs and cull breeding hogs sales. The records came from Michigan State University’s TelFarm project and the Farm Credit Service system in Michigan. The values were pooled into averages for reporting purposes.
Farm records were included if a farm financial summary was completed on 2006 data including beginning and ending balance sheets, plus income and expenses. The data were checked to verify that cash discrepancy was less than 10% of gross cash inflow and that debt discrepancy was less than $1,000. While considerable variation in the data exists, average values are reported in the summary tables listed in this article.

A note on the preference of naïve horses for different water bowls.

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The objective of this study was to determine the preference of naïve horses for different types of water bowls. Four different bowls were tested: two float valve and two push valve models were tested. Water consumption was measured in two groups of horses (n=8 and n=11) and three individual horses. The push valve water bowls were hardly used. There appeared to be a slight preference for one model of the float valve over the other when the horses came to drink as a group. This difference was significant when individual horses were studied. The preferred float valve bowl had a larger, more open bowl, which could hold a greater volume of water that remained in the bowl due to the float valve. Therefore, there was not a tendency for frequent refilling of the bowl, which could startle the horses, and could have led to less preference for the other types of water bowls.

Welfare Index and Reproductive Performance in the Sow

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Actions promoting production animal welfare are often seen as investments without reward. By definition, high welfare is characterized by low levels of stress (Broom and Johnson 1993). As stress is shown to have adverse effects on reproduction (Dobson and Smith 2000), a low level of welfare may be suspected to have similar output. Many effects of management on pig reproduction are basically understood. These factors influence the wellbeing of animals, and when combined they can be used to assess welfare. There are probably no studies published on effects of animal welfare on productivity, if welfare is considered a state comprised of several contributing factors as housing, stockmanship etc. Poor health or productivity in animals can be used as an indicator of poor welfare. Good health and especially productivity can, however, not be taken as conclusive evidence of good welfare (Scientific Veterinary Committee
1997). Detrimental effects on reproductive performance are to be expected only when welfare is considerably compromised, because coping systems of animals have evolved to minimize effects of stress on reproduction (Dobson and Smith 2000). The Scientific Veterinary Committee states that ‘If there are differences between systems, even a small effect on reproduction may indicate considerable welfare problems’ (Scientific Veterinary Committee 1997). The Animal Needs Index TGI 35L (Tiergerechtheitsindex) is a scoring method developed to certify the level of pig, cattle and lying hen welfare on farms (Bartussek 1999). Points are assigned to easily identifiable attributes of the housing system. Management, health and behaviour parameters are noticed superficially. Based on knowledge of the needs of the animals more points are given for favourable circumstances. All points are summed for a final score that judges the prerequisites for animal welfare. The assessment of welfare by TGI 35L is classified as indirect, because most aspects are environment-based (Johnsen et al. 2001). Objectives of the study were to investigate the relationship between different parameters describing on-farm sow welfare and reproductive performance. Welfare was assessed using a modified TGI 35L–Animal Needs Index. The modified index had a maximal total score of 100. It was comprised of six categories: ‘locomotion’ (maximal score 21 for dry sows and 11 for lactating sows), ‘social interaction’ (12/8), ‘floor quality’ (16/9), ‘stable climate’ (16/21), ‘feeding’ (16/23) and ‘health and stockmanship’ (19/29). Index scorings were performed separately in farrowing, breeding and gestation units on 28 representative Finnish sow farms. One-year production parameters were collected. Multiple linear regression was used for statistical analysis. Total ANI-points varied between 36.5–68.0 for lactating and 39.5–86.0 for dry sows. Litter size increased with increasing scores for ‘feeding’ in the dry sow unit. Controlling for breed, high scores for ‘health and stockmanship’ and ‘floor quality’ shortened the reproductive cycle, probably because of good leg health. The number of weaned piglets per sow per year (PSY) increased with increasing scores for dry sow ‘health and stockmanship’, ‘floor quality’ and an interaction of ‘feeding’ in the farrowing and mating units. PSY increased with decreasing scores for farrowing pen ‘climate’. It was concluded that high-quality floors and stockmanship appear to correlate positively with reproductive performance in the sow; however, the effects of a welfare-promoting feeding strategy on reproduction are contradictory.

Porcine Circovirus Associated Disease (PCVA)… a “Double Bogey”

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Symptoms of PCVAD include: gross lesions; microscopic lesions; hallmark lymphoid lesions; immunohistochemistry; main confirmatory test; serology; ELISA, IFA; PCR; quantitative, nested, multiplex; virus isolation; sequencing; and antigen capture ELISA.
An assessment was done on boars using ELISA or IFA to determine PCV2 status because naïve incoming boars may represent a risk. Producers must consider exposing naïve boars to PCV2, either by Vaccination or PCV2 positive (by PCR or Antigen Capture ELISA) feces from resident boars 5 weeks prior to bringing them into the main stud. In order to assess the breeding herd use ELISA or IFA to determine PCV2 status. Naïve incoming gilts may represent a risk. Consider exposing naïve gilts to PCV2 by vaccination or planned exposure (fecal feedback, mummified fetus feedback, cull sow exposure). In order to assess the nursery or finisher pigs confirm that PCVAD is a problem by histopath and IHC; use ELISA or IFA to determine when maternal antibodies wane and to determine when seroconversion occurs; do PCR on pooled serum (or saliva) to further define time of infection; do some PCV2 sequencing so you have a historical record of the system. If morbidity and mortality are unusually high, use sequencing to determine if the PCV2 in the system has changed. PCV2 isolates that are genetically highly homologous may differ in virulence. These differences may explain differences in clinical manifestation of PCV2 associated diseases. An experiment was done to determine the effects of host genetics on susceptibility to PCV2-associated disease and lesions. It was concluded that 3/19 (15.8%) Landrace pigs developed PMWS whereas none of the Duroc or Large White pigs developed PMWS. There was significantly more severe lymphoid depletion in tonsils and lymph nodes of Landrace pigs. The Landrace pigs used in this study appear to be predisposed to PCV2-associated lymphoid depletion and PMWS. Reproduction of severe disease and lesions typical of PMWS in CDCD pigs co-infected with PCV2 and PRRSV resulted in a 90% mortality in coinfected group, no mortality in singular PRRSV group and less severe disease and lesions in PCV2 only group (40% mortality). PCV2 and PPV coinfected conventional SEW pigs had increased incidence and severity of clinical signs characteristic of PMWS. There was also a significantly higher incidence and more severe lymphoid depletion observed in coinfected pigs. The PCV2 coinfection Model characterized severe disease by coughing, dyspnea, lethargy and decreased growth. Dual infected pigs had significantly more severe lung lesions and a significantly higher number of genomic copies of PCV2 in sera at 14 and 21 DPI. They also had more severe lymphoid depletion and higher amounts of PCV2 antigen in lungs and lymphoid tissues. A field trial looked for evidence for immune stimulation induced progression of PCV2 infection to PMWS. They found PMWS in 42.9% of the vaccinated pigs versus 10.7% in the group treated with normal saline. This work provides evidence that the efficacy of PRRSV vaccines can be decreased when administered to PCV2- infected pigs. Based on field evidence, we suspect that PCV2 infection may similarly decrease the efficacy of other vaccines administered between 6-14 weeks of age. The use and the appropriate timing of M. hyo vaccination is an effective tool in reducing the production losses associated with PCV2 and M. hyo-induced respiratory disease complex. Another experiment confirmed that the use of CTC (Aureomycin®) in the feed for 2-4 weeks at an approximate dose of 22 mg/kg body weight is a highly effective tool in reducing the production losses associated with PCV2- and M. hyoinduced respiratory disease complex. In order to control PCV2-Asscociated Diseases confirm PMWS/PCV2 by histopath, IHC; identify and control concurrent viral infections; minimize effects of M. hyo. with commercial vaccines and/or antimicrobials; aggressively treat other bacterial coinfections; determine if there is an association of increased PCV2-induced disease with the use of certain vaccines or timing of vaccination; use anti- inflammatory drugs; pulsing the group with spray dried plasma protein; pull sick pigs; focus on decreasing stress and improving pig comfort; use effective disinfectants (Virkon-S) between groups; consider a change in pig genetics; and use PCV2 vaccines. These are all ideas that will help control the outbreak of PCV2 in swine barns.