Efeitos do fornecimento oral de suplementos nutricionais na sobrevivência e crescimento de leitões de baixo peso ao nascer

Abstract

Background: High mortality is observed in piglets of low birth weight mainly due to their low body reserves and low colostrum consumption. Although nutritional supplements can be offered to these piglets in order to increase their survival and growth performance, the results concerning the beneficial effects of oral nutritional supplementation are still controversial. The aim of this study was to evaluate the effect of oral supply of nutritional supplements to low birth weight neonates, in the first hours of life, on their colostrum consumption, serum immunoglobulin G, rectal temperature, weight gain and mortality. Materials, Methods & Results: At birth, piglets with birth weight ranging from 794 to 1315 g were selected and randomly distributed among four treatments according to the nutritional supplement provided: Control (n = 305), Lianol (n = 306), Biostart (n = 306) and Lianol+Biostart (n = 305). At the first 24.3 ± 0.04 h after birth piglets remained with their biological mother and after that they were transferred to foster dams forming litters of 12 piglets, which were equally distributed among treatments (3 piglets of each treatment). At 24 h after birth, rectal temperature was measured (n = 143, n = 147, n = 152 and n = 144 piglets from Control, Lianol, Biostart, Lianol+Biostart groups, respectively), blood was collected to measure serum immunoglobulin G (21 animals per treatment) and all alive piglets were weighed to estimate the colostrum consumption. The mortality was recorded daily and necropsy was performed to determine the cause of death. The weight was measured at birth, at 24 h, 7 and 20 days after birth. The supplementation had no effect (P > 0.05) on rectal temperature at 24 h (38.8 ± 0.02ºC), colostrum consumption (274.3 ± 2.8 g) and serum IgG (24.2 ± 0.98 mg/mL). Overall, the body temperature and colostrum consumption were respectively lower in piglets of <1000 g (36.5 ± 0.07ºC; 222.9 ± 5.4 g) compared with those of 1000-1225 g (36.8 ± 0.06ºC; 275.4 ± 4.3 g) and >1225 g (37.1 ± 0.07ºC; 310.9 ± 5.6 g). The body weight (1179.2 ± 4.9 g, 2153.3 ± 12.3 g and 4858.5 ± 32.3 g) and the weight gain (79.2 ± 2.1 g, 149.8 ± 1.5 g and 206.7 ± 1.9 g) at 24 h, 7 and 20 days, respectively, were not different among treatments (P > 0.05). There was no difference (P > 0.05) among treatments in mortality on days 3 (4.7%), 7 (6.9%) and 20 (8.8%) after birth. In piglets weighing 1000-1225 g at birth, the mortality up to 20 days was lower (P ≤ 0.05) in Lianol (6.1%), Biostart (6.8%) and Lianol+Biostart (5.5%) groups than in Control (13.6%) group. There was lower (P < 0.05) pre-weaning mortality due to crushing and undernutrition in Lianol and Biostart groups than in the Control group (4.9% x 4.2% x 9.2%; respectively) Discussion: The mortality of piglets weighing 794-<1000 g was not reduced by nutritional supplementation probably because the additional energy provided to these piglets was unable to overcome the effects of their lower body temperature and their colostrum consumption below the minimum of 250 g, considered as the minimum amount to guaranty the survival. Piglets of 1000-1225 g had adequate colostrum consumption (about 15 g above the minimum) and, probably, the nutritional supplementation was enough to reinforce their minimal physiological and metabolic conditions, hence increasing their survival. The low mortality of heavier piglets (>1225 g) is probably associated to their higher body reserves and to their higher colostrum consumption (about 60 g above the minimum necessary). Furthermore, it is known that survival of heavy piglets is higher, regardless of their colostrum consumption. In conclusion, the benefit of the nutritional supplementation on survival until weaning is observed in piglets weighing 1000-1225 g, but not in those with weight below or above this range.