title: Comparison of growth performance and agonistic interaction in weaned piglets of different weight classes from farrowing systems with group or single housing.
abstract: The present study was designed to analyze the growth performance, behavioral patterns and intensity of injuries of weaned pigs (26 days) during a rearing period of 6 weeks. The farrowing system (group housing (GH) v. single housing (SH)) and the post-weaning regrouping weight class (light, medium, heavy) were considered as the main factors. A number of 120 GH-pigs and 120 SH-pigs were kept in three batches (20 pens, 12 pigs each). The GH- and SH-pigs were divided by weight into three groups: light (5 to ⩽7 kg), medium (>7 to ⩽9 kg) and heavy (>9 to ⩽12 kg), with two pigs of six different litters in each pen. The pigs were weighed individually at weaning (week 1) and during rearing (weeks 2, 3 and 7). The feed conversion ratio (FCR) was calculated between weeks 1 and 7. The duration and number of fights (NF) per pen and hour were determined by continuous sampling (40 h after weaning). Lesions of the integument were scored into four classes (none, minor, medium, severe) and recorded at weaning and 48 h afterwards. The farrowing system had no effect on the weights in week 1 (GH: 7.8 kg v. SH: 7.7 kg; week as linear, quadratic regression nested within housing systems) or in week 7 (GH: 29.4 kg v. SH: 28.6 kg). The body weights were influenced significantly by the weaning weight class (light: 11.7 kg (s.e.m.: 0.30), medium: 14.8 kg (s.e.m.: 0.22), heavy: 17.3 kg (s.e.m.: 0.26)). The FCR of the GH-pigs was 1.64 (s.e.m.: 0.03) and 1.58 (s.e.m.: 0.03) for SH-pigs. A reduced agonistic behavior of the GH-pigs was observed with 2.1 fights per pen and hour (s.e.m.: 0.07) v. the SH-pigs with 4.6 fights per pen and hour (s.e.m.: 0.05). The fight duration of the GH-pigs with 10.3 s per pen and hour (s.e.m.: 1.07) was significantly lower in comparison to the SH-pigs with 18.8 s per pen and hour (s.e.m.: 1.06). The SH-pigs had more new skin lesions at the shoulders than the GH-pigs 48 h after weaning (P < 0.05). In conclusion, early mixing of unacquainted litters during lactation had no influence on their growth performance during rearing but reduced agonistic behavior and lesion score difference during the first 2 days after weaning. No significant interaction between the farrowing system and weaning weight class was detected with regard to growth performance and NF.
authors.affiliation: Institute of Animal Breeding and Husbandry, Christian-Albrechts-University, Olshausenstraße 40, D-24098 Kiel, Germany. abohnenkamp@tierzucht.uni-kiel.de
authors.forename: A-L
authors.initials: AL
authors.lastname: Bohnenkamp
authors.forename: I
authors.initials: I
authors.lastname: Traulsen
authors.forename: C
authors.initials: C
authors.lastname: Meyer
authors.forename: K
authors.initials: K
authors.lastname: Müller
authors.forename: J
authors.initials: J
authors.lastname: Krieter
mesh_terms: D000378:Agonistic Behavior; D000822:Animal Husbandry / Q000379:methods*; D000818:Animals; D001835:Body Weight; D005260:Female; D006799:Housing, Animal / Q000592:standards; D008297:Male; D034421:Sus scrofa / Q000254:growth & development / Q000502:physiology*; D014886:Weaning