Group size and floor-space allowance can affect weanling-pig performance

• Published in: Journal of animal science Vol. 78; no. 8; pp. 2062 - 2067
• Main Authors: Wolter, B. F, Ellis, M, Curtis, S. E, Parr, E. N, Webel, D. M
• Format: Journal Article
• Language: English
• Published: Savoy, IL Am Soc Animal Sci 01.08.2000; American Society of Animal Science; Oxford University Press
• Subjects: Animal productions; Animals; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Groups; Hogs; Housing, Animal; Physical growth; Random Allocation; Shelters; Swine - growth & development; Terrestrial animal productions; Vertebrates; Weaning; Performance evaluation; Farming animal; GROUP SIZE; Experimental study; Weight gain; Pig; Vertebrata; Meat animals; Mammalia; Animal housing; Artiodactyla; REARING TECHNIQUES; Ungulata; Population density
• ISSN: 0021-8812; 1525-3163; 0021-8812
• DOI: 10.2527/2000.7882062x

Crossbred weanling piglets (n = 1,920; mean initial BW, 5.3 +/- .7 kg) were used in two 9-wk trials employing a randomized block design in a 2 x 2 factorial arrangement of treatments to determine effects of group size (20 [Small = S] or 100 [Large = L] pigs/pen) and floor-space allowance (calculated requirement [CR] or calculated requirement less 50% of estimated "free space" [CR-50]) on growth performance. Free space was estimated for each group size. From wk 1 through 4 after weaning, S and L groups at CR were allowed a floor space of .17 m2/pig, and at CR-50, S and L groups were allowed .15 m2/pig and .13 m2/pig, respectively. From wk 5 through 9 after weaning, all CR treatment pigs were provided a floor space of .38 m2/pig, and for the CR-50 treatment, S and L pigs were allowed .32 m2/pig and .28 m2/pig, respectively. Piglets had free access to feed and water. Feeder-trough space per pig was the same for both group sizes. Feed-intake data were collected for only wk 1 through 4. Group size by floor-space allowance interactions (P < .05) were found for gain/feed ratio (G/F) for wk 1 and wk 2 through 4, but not for wk 1 through 4. Piglets in L groups were lighter (P < .001) at the end of wk 1, 4, and 9 by 2, 4, and 5%, respectively, and had lower ADG (6%; P < .001) throughout the trial than S piglets. During wk 1 through 4, feed intake was lower (7%, P < .001) in L piglets than in S piglets, but G/F was similar (P > .05). Piglets in CR groups had greater ADG (5%; P < .01) throughout the trial, with a greater G/F (P < .05) for wk 1 through 4, and were heavier (P < .01) than those in CR-50 groups at the end of wk 4 (3%) and 9 (4%). Pigs in L groups had a greater within-pen coefficient of variation in BW at the end of wk 9 than pigs in S groups. Large groups and reduced floor-space allowance reduced piglet growth performance in the nursery.