Sow Functional Teat Number Impacts Colostrum Intake and Piglet Throughput

Teat number is a commonly used metric to evaluate underline quality at replacement gilt selection. A minimum number of teats is typically suggested for entry into the breeding herd, yet this criterion may be forgiven when demand for gilts is high. The objective of the present study was to characterize the importance of sow functional teat number (TEAT) on piglet colostrum intake and litter throughput. Second parity Landrace x Large White sows (n=59) farrowed at the North Carolina Department of Agriculture Tidewater Research Station (Plymouth, NC) summer 2017. At birth, piglets (n=834) were individually identified and weighed prior to first suckle (BWT). Piglets were reweighed at 24 h of age and individual piglet colostrum intake estimated using an equation incorporating BWT, 24 h weight gain and duration of suckling. Sow colostrum production was calculated as the sum of individual piglet colostrum intakes in the litter. During farrowing, sow teats were counted and sampled for functionality, defined as the ability for milk to be stripped from the teat. Weaning traits included number weaned (NW), average 21 day piglet weight (WWT), total litter WWT and piglet survival. Piglet survival was calculated as NW ÷ total number born (TNB). Variables were analyzed in SAS using PROC GLM with TEAT and litter size included as quantitative variables. Sow was the experimental unit. Average TNB, number born alive, BWT, and piglet survival was 13.8±3.8 piglets, 13.1±3.1 piglets, 1.32±0.2 kg, and 80.0±0.1%, respectively. Average total teat number and functional teat number were 15.03±1.1 and 14.83±1.0 teats per sow, respectively. As TEAT increased, both piglet colostrum intake and total sow colostrum production improved (P<0.01). At weaning, TEAT did not impact (P>0.05) WWT. Yet a one nipple increase in TEAT improved (P<0.05) piglet survival by 3.25% and total litter WWT by 3.6 kg and tended (P=0.10) to increase NW by 0.34 piglets. Results suggest identifying females with increased TEAT number would enhance piglet colostrum intake and piglet throughput.