Effects of floor area allowance and group size on the productivity of growing/finishing pigs.

Abstract

Six group sizes and three levels of floor area allowance were studied in a 6 x 3 factorial arrangement. Group sizes were 3, 5, 6, 7, 10, and 15 pigs per pen. Floor area allowances were .030, .039, and .048 m2 x BW(.667). All pens were square and equipped with a single space feeder and nipple drinker near one corner. Pigs were fed a pelleted diet. Initial weights averaged 25.0 kg, and pigs remained on test for 12 wk. Pigs were weighed, feed intake was determined, and size of pens was increased at 2-wk intervals. Pen size was adjusted to provide the space required for the midpoint of each weigh period. Two replicates of the study were conducted. The ADG was reduced with increasing group size (899, 851, 868, 872, 857, and 821 g, SEM = 16.4, for 3, 5, 6, 7, 10, and 15 pigs, respectively; P < .05), but the CV for gain (mean = .185) did not differ among group sizes. The ADFI also decreased with increasing group size (2.49, 2.34, 2.32, 2.28, 2.28, and 2.21 kg, SEM = .036, for 3, 5, 6, 7, 10, and 15 pigs, respectively; P < .05). Feed efficiency (gain/intake) was highest for group sizes of 7 and 10 pigs (.381) and lowest for pens of three and five pigs (.363; P < .05). The ADG and ADFI (832 g and 2.25 kg, respectively) for the most crowded space allowance were reduced compared to more spacious allowances (ADG and ADFI of 875 and 877 g, and 2.35 and 2.36 kg, for .039 and .048 m2 x BW(.667), respectively; P < .05). Efficiency did not differ among space allowances. These results confirm previous studies reporting a negative effect of increasing group size on productivity, but our study suggests that gain and intake reach a plateau at less space allowance than previously reported.

Impacts of Nutrition and Environmental Stressors on Lipid Metabolism

“…In a study using this approach, housing densities of 0.578, 0.761 and 0.942 m 2 /pig corresponding to housing area coefficients of 0.030, 0.039 and 0.048, respectively; resulted in decreased ADG and ADFI in pigs housed at floor area allowances with coefficients between 0.030 and 0.039 [71]. These results were within in the range of other reported housing threshold values [71].…”

“…Housing densities between 0.76 and 0.93 m 2 /pig have been reported as the threshold for grow-finish swine, below which ADG and ADFI are reduced [71].…”

“…Decreasing space allocation reduces growth performance and the minimal spatial requirements for grow-finish pigs have been examined [36,71]. Housing densities between 0.76 and 0.93 m 2 /pig have been reported as the threshold for grow-finish swine, below which ADG and ADFI are reduced [71].…”

“…One allometric calculation for spatial allocation is f = k x BW .667 (f = floor allowance, m 2 ; k = coefficient of housing area; BW = body weight, kg) which accounts for the relationship between body weight and surface area [71]. In a study using this approach, housing densities of 0.578, 0.761 and 0.942 m 2 /pig corresponding to housing area coefficients of 0.030, 0.039 and 0.048, respectively; resulted in decreased ADG and ADFI in pigs housed at floor area allowances with coefficients between 0.030 and 0.039 [71]. These results were within in the range of other reported housing threshold values [71].…”

Why are most EU pigs tail docked? Economic and ethical analysis of four pig housing and management scenarios in the light of EU legislation and animal welfare outcomes

“…Finally, we have assumed that all scenarios have a similar level of productivity, but increased space allowance can improve both average daily gain (Gonyou and Stricklin, 1998) and feed conversion ratio (Turner et al, 2000). Meta-analysis suggests a linear relationship between space and weight gain, but only up to a threshold after which further increases in space have no further effect (Gonyou et al, 2006).…”