T. Schmidt, M. Grodzycki, M. Paulick, F. Rau, E. von Borell * Martin-Luther University Halle-Wittenberg Department of Animal Husbandry & Ecology

Transcription

1 Impact of single-sex and mixed-sex group housing of boars physically castrated or vaccinated against GnRH (Improvac ) on feeding duration and shoulder lesions T. Schmidt, M. Grodzycki, M. Paulick, F. Rau, E. von Borell * Martin-Luther University Halle-Wittenberg Department of Animal Husbandry & Ecology

2 Introduction: Piglet Castration & Alternatives Physical castration without pain-treatment in most countries Boar - Taint Alternatives are sought to improve pig welfare (review: von Borell et al., 2009; PIGCAS, 2009) GnRF vaccination licensed in most major pig-producing countries (Improvac, Pfizer Animal Health)

3 Introduction: GnRF Vaccination (Improvac, Pfizer Animal Health) 1st 4 wks 2nd 4-6 wks slaughter Priming GnRF Antibody Production Temporal suppression of testes function from ~1 to at least 8 wks after 2nd vacc. Aggression, Mounting, Activity Cronin et al., 2003 Baumgartner et al., 2010 Rydhmer et al., 2010 Further research needed regarding welfare aspect (Prunier et al., 2006; Baumgartner et al., 2010)

4 Introduction: Aim of study Most aggressive interactions occur during feeding (Meese & Ewbank, 1973) Feeding behaviour: Influenced by higher aggression level? Dunshea et al., 2001; Cronin et al., 2003 Skin lesions: Impact of aggressive interactions on health? Mixed-sex housing can reduce aggression (Séguin et al., 2006; Boyle & Björklund, 2007, Borberg & Hoy, 2009)

5 4 Treatments Physically Castrated GnRF- Vaccinated Single - Sex N = 10 (per pen) Mixed - Sex N = 5 / 5 (per pen)

6 Physically Castrated GnRF- Vaccinated Pi x (LW x German LR) 4 Replicates = 160 animals 2 weeks Statistical analysis (JMP, SAS Institute Inc.): Repeated measure mixed models & Tukey-Kramer HSD Fixed effects: treatment, time & treatment x time Random effects: pen and replicate 2 weeks 2 weeks

7 Methods: Feeding behaviour 1 IVOG Single-Space Station per Pen (Insentec, The Netherlands) Plausibility analysis adapted from Eissen et al., 1998 Feeding duration per visit & day (min) Feed intake per day (g) & per visit, ADG Visits per day (#) Feeding speed (g/min)

8 Methods: Skin Lesion Scores Indirect measure of aggression Turner et al. (2006) Evaluations of 10 body regions for each pig weekly throughout the fattening time > Shoulders susceptible to fighting Scores 1-2 (scratches) Scores 3-4 (graze/abrasion) Scores 5-6 (severe wound) (adapted from Ekesbo, 1984)

9 Results: Feeding duration per visit Phys. Castr Vaccinates Phys. Castr + Females Vaccinates + Females 1,8 2nd n.s. (log, min ) 1,4 1 n.s. 0,6 0,2 LS means + SEM wk 14 wk 20 wk 25

10 (g) Results: Feed intake per day Phys. Castr Vaccinates Phys. Castr + Females Vaccinates + Females nd LS means + SEM wk 14 wk 20 wk 25

11 Results: ADG Phys. Castr Vaccinates Phys. Castr + Females Vaccinates + Females 1050 (g) LS means + SEM before 2nd vaccination after 2nd vaccination

12 LS means + SEM Results: Shoulder Lesions Phys. Castr Vaccinates Phys. Castr + Females Vaccinates + Females 2,4 2,2 n.s. 2nd Score 2 1,8 1,6 1,4 1,2 1 n.s. P1 (11-13wks) P2 (14-18wks) P3 (19-23wks) P4 (24-28wks)

13 Summary / Discussion: Single-sex Vaccinates: Shorter feeding duration, due to more aggression? Confirmed by higher shoulder lesion scores Consistent with more aggressive behaviour in other single-sex studies Cronin et al., 2003 Baumgartner et al., 2010 Rydhmer et al., 2010 Not consistent with Mixed-sex Vaccinates: Feeding duration (per visit) and lesion scores NOT different from Physical Castrates Less aggression at the feeder in mixed-sex groups Boyle & Björklund (2007) Lesion scores mainly superficial scratches, not severe wounds No disadvantages apparent after 2 nd vaccination with effective suppression of testes function

14 Thank you! Acknowledgements Pfizer Animal Health State Institute for Agriculture in Saxony Anhalt, Germany

15 Results: Feed intake per visit Phys. Castr Vaccinates Phys. Castr + Females Vaccinates + Females 6 5,5 FIV (log, g) 5 4,5 4 3,5 wk 14 wk 20 wk 25

16 Results: Feeding duration per day Phys. Castr Vaccinates Phys. Castr + Females Vaccinates + Females 65 (min) n.s LS means + SEM wk 14 wk 20 wk 25

17 scratch graze/abrasion severe wound n 5 1 n > 5 2 superficial 3cm 3 > 3cm 4 single deep cut, bleeding 5 multiple lesion, necrosis 6