Influência do peso ao nascimento e de lesões orais, umbilicais ou locomotoras no desempenho de leitões lactentes

Abstract

Background: Several factors infl uence the survival and performance of piglets during lactation. Birth weight appears as one of the most important factors affecting the survival of piglets, mainly during the fi rst week after birth. There is also a positive correlation between birth weight and weaning weight. In addition to the birth weight, the presence of oral, umbilical or limb lesions can compromise the performance of suckling piglets, affecting their weaning weight. Although limb lesions are common among suckling piglets, there is little information associating these lesions with piglet performance. The aim of this study was to evaluate the infl uence of birth weight as well as of oral, umbilical or limb lesions on mortality and performance of piglets at 7, 14 and 21 days of age. Materials, Methods & Results: The study was performed in a pig farm located in Rio Grande do Sul State, Brazil. A total of 2004 piglets were evaluated for the presence of oral (at the fi rst day of life), umbilical and limb lesions (at the end of fi rst and second weeks of life). Piglets were weighed at birth and at 7, 14 and 21 of age. Overall, birth and weaning weights were respectively 1546 ± 8.2 g and 5837 ± 32.0 g (means ± SEM). Mortality rate from birth to weaning was 4.7% and 79.0% of deaths occurred during the fi rst week of life. Piglets with birth weight until 1200g showed pre-weaning mortality higher (P < 0.05) than heavier piglets (13.0% - 47/362 vs 2.9% - 48/1642). The occurrence of oral lesions at the fi rst day of life did not affect the survival of piglets until weaning. Birth weight was positively correlated with weaning weight (r = 0.515; P < 0.001). The difference between lighter (> 600 g - 900 g) and heavier piglets (> 2100 g) was 1477 g at birth and 3229 g at weaning. Occurrence of oral or umbilical lesions did not compromise the piglet performance. The presence of limb lesions affected negatively the weaning weight (P < 0.05), mainly when lesions were present in the second week of life. Body weight at 21 d of age was higher (P < 0.05) in piglets without lesions (5957 ± 30.4 g) than in piglets with lesions at the second week (5417 ± 125.9 g) or in those with lesions at both fi rst and second weeks of life (5218 ± 104.2 g). Discussion: The mortality rate of 4.7% observed during lactation is lower than that observed in other reports. The occurrence of a low mortality rate in this study may refl ect the continuing presence of employees in facilities and intensive care provided to the piglets at farrowing and during the suckling period. In agreement with other studies, lighter piglets presented higher pre-weaning mortality than heavier piglets, and 70.5% of deaths occurred in piglets weighing between 600 g and 1500 g. Birth weight was also shown to be a determinant factor for weight gain until weaning, confi rming the results of previous studies. Piglets with a low body weight at birth have low body energy reserves and a reduced ability to maintain their body temperature. These aspects result in a lower colostrum and milk intake, a reduction of passive immunity and undernourishment, resulting in a lower survival and pre-weaning performance. It has been shown that most of limb lesions may cause only discomfort to piglets, but can also act as a gateway to infectious pathogens which result in relevant lesions. The reduction of body weight observed in piglets which had limb lesions during the second week of life may be associated with the fact that from this week onwards there is an increase in daily weight gain of piglets, then limiting their potential body weight gain if lesions are present during this phase.