Relationship of sow udder morphology with piglet suckling behavior and teat access.

The aim of this study was to investigate if there is a relationship between the latency to the first suckling and udder and teat morphology and to assess the extent to which piglet and sow characteristics influence teat pair position preference. Udder morphology trait measurements, piglet suckling behavior, and sow productive and behavioral traits were recorded from a population of 74 Large White X Landrace sows of different parities. The interteat distance within the same row was larger between the teats that were suckled at the first contact with the udder compared with the unsuckled teats (P = 0.04). There was a tendency for piglets to suckle first from teats placed closer to the abdominal midline. A high proportion of siblings (64%) suckled for the first time on a teat previously chosen by another piglet. Most neonates suckled first from a teat located in the posterior part of the udder (41%) or in the anterior part (33%), rather than the middle section. Latency from birth to suckling and the time from the first udder contact to locate a teat and suckle was shorter for piglets first suckling the anterior (28:03 and 9:48 minutes) and posterior teats (26:31; 8:38 minutes) than for those sucking the midsection teats (34:30 minutes, F7,256 = 1.99, P = 0.05; 10:30, F7,256 = 2.37, P = 0.05). To avoid possible confounds, other potential causes of delay in successful suckling were studied. The latency to suckle was not influenced by piglet vitality score at birth, weight, or provision of human assistance to place it at the udder. It was shorter when the piglets were born later in the litter (P < 0.001), from a litter with a low incidence of piglets born dead (P = 0.001) and from a sow with an induced farrowing (P = 0.007). Moreover, there was a tendency for piglets born from a multiparous sow (P = 0.06) and in a large litter size (P = 0.07) to have a longer latency to find a teat and suckle once they had made the first contact with the udder. Although suckling itself is clearly an instinctive behavior, acquisition of colostrum depends on many variables, relating not only to piglet characteristics but to sow behavioral and morphological characteristics as well. Future studies on sow characteristics are therefore recommended.