LAUSR

This study evaluated the relationship between teat order and its impact on feed consumption in pigs through nursery. Pigs were observed 48 h after birth to be in either a cranial, middle, or caudal teat position. Growth performance data, and active and total plasma ghrelin concentrations (determined by radioimmunoassay) were analyzed from 2 pigs in each position from 6 litters (n = 36) at 7 d of age, 21 d of age (weaning), and 62 d of age (end of the nursery stage) to determine a relationship with teat order. At weaning, pigs were moved to an off-site nursery and housed 2 pigs/pen based on teat position and litter, resulting in 6 pens/teat position. Overall, no effect of teat order was found on average daily gain (ADG; P = 0.91), average daily feed intake (ADFI; P = 0.67), gain-to-feed ratio (G:F; P = 0.33), or body weight (P = 0.94) among pigs from each teat position. A linear relationship was found between teat order and ADG (P = 0.01) as well as G:F in nursery phase-1 (P = 0.01) with caudal pigs gaining more rapidly and being more efficient than cranial pigs. Yet, in nursery phase-2, cranial pigs had the greatest ADFI (linear, P = 0.05). No difference was seen in active (P = 0.18) or total (P = 0.63) ghrelin concentrations or the active to total ghrelin ratio (P = 0.68) in relation to teat order, although there were differences in active (P = 0.04) and total (P < 0.01) ghrelin concentrations among the sampling days with the least concentrations being on d 21 for active and total ghrelin. Further study should investigate what factors would contribute to these data contradicting previous inferences about the relationship of teat order and feed consumption in pigs