Effect of Protein Restriction in Sows during Gestation and Lactation on Visceral Organ Mass and Serum Hormones Concentration in the Offspring

In the pig, under-nutrition in utero causes low birth weight, a decrease in muscle fiber number, and a reduction in postnatal growth rate. Low protein intake during gestation and lactation has been demonstrated to increase the loss of body protein and to reduce the visceral organ mass of the newborn piglets. The effect of under-nutrition of pregnant swine on subsequent serum hormones characteristics of their offspring was investigated. The trial involved 16 pregnant MeiShan sows. The swine were allocated randomly to one of two groups: a treatment group (n=8) and a control group (n=8). During gestation and lactation, the diet of the treatment group was decreased to 50% of their daily protein requirement. The control group was fed 100% of their daily requirement to support the swine growth throughout gestation and lactation. All of swine were artificial insemination mated. Diets provided similar amounts of metabolizable energy. In this experiment, organ weights of piglets were reported as fresh weight (grams), scaled to empty body weight (EBW; grams per kilogram ). Serum hormones of offspring were sampled at 0 d, 15 d and 35 d of lactation. Piglets were slaughtered at 0 d and 35 d of lactation for organ weight determination. The objectives of the current experiment were 1) to determine whether protein restriction alters levels of somatotropic hormones, insulin, insulin-like growth factor-1, thyroid hormones, and 2) to evaluate the relationship between these eventual alterations and visceral organ mass in piglets. During lactation, dietary protein restriction decreased liver, spleen and kidney mass (p<0.01). But dietary protein restriction did not affect heart mass (p>0.05). Reduced protein intake decrease mean and basal plasma GH in piglets at 0 d, 15 d and 35 d (p<0.01). Mean insulin and insulin-like growth factor-1 concentrations were similar in both groups during lactation (p>0.05). Mean and basal plasma T3 were higher (p<0.01), whereas plasma T4 were lower in control group than in treatment group piglets on day 0. Mean T3 concentration on day 15 and mean T4 on day 35 were very significantly higher than control group. In conclusion, these results provide evidence that protein restriction throughout gestation and lactation alters circulating concentrations of hormones and has a negative impact on visceral organ mass. [World Rural Observations 2009;1(2); 77-86]. ISSN: 1944-6543 (print); ISSN: 1944-6551 (online).