Evaluation of Sow Caliper for body condition measurement of gestating sows

Abstract

Objectives: To evaluate correlation between Sow Caliper measurement and backfat depth (BFD), and to determine the ideal caliper measurement that predicts optimal BFD prefarrowing to support performance of lactating sows. Materials and methods: Multiparous sows (n = 928, Parity 1-9) were group housed in pens from day 35 to 109 of gestation. Caliper measurements, BFD, visual body condition scores (BCS), and body weight were recorded upon sows’ entry and exit of gestation pens. Subsequent farrowing performance was recorded. Caliper measurements were classified into five categories: category 1 = 4.0 to 8.0 units, category 2 = 8.5 to 10.0 units, category 3 = 10.5 to 12.0 units, category 4 = 12.5 to 14.0 units, and category 5 = 14.5 to 18.0 units. Results: Caliper measurement was correlated positively with BFD (r = 0.71-0.75; P < .001) and BCS (r = 0.67-0.75; P < .001) on days 35 and 109 of gestation. Based on sow performance over one reproduction cycle and BFD recommendations, caliper category 4 on day 109 of gestation was deemed ideal for prefarrowing sows. The estimated lower and upper limits of BFD for prefarrowing sows in caliper category 4 were 15.6 and 18.0 mm, respectively. Caliper measurements explained about 55% of variation in BFD of gestating sows prefarrowing. Implications: The Sow Caliper can be used to evaluate body condition of gestating sows. To maintain body condition and reproductive performance, caliper measurements of 12.5 to 14.0 units are recommended for prefarrowing sows across parities, excluding gilts.