Reduced feed intake of lactating primiparous sows is associated with increased insulin resistance during the peripartum period and is not modified through supplementation with dietary tryptophan1

Abstract

The aim of this experiment was to investigate whether insulin resistance is related to the dietary concentration of Trp and the ADFI of primiparous sows having similar body conditions. Twenty-four primiparous sows were catheterized on d 97 of pregnancy. Blood samples were collected during 3 tests: after the ingestion of 1.5 kg of feed (meal test), after the intravenous infusion of 0.5 g of glucose/kg of BW (glucose tolerance test), and during an euglycemic hyperinsulinemic clamp with an infusion rate of 100 ng of insulin x kg of BW(-1) x min(-1). Both tests were performed at 4 stages at approximately d 103 and 110 of pregnancy and at d 3 and 10 of lactation. Sows were fed a diet containing 0.16 or 0.26% of total Trp (suboptimal vs. slight excessive Trp supply according to recommendations for lactating sows) from d 104 of pregnancy after the first clamp until weaning. The dietary treatment did not result in differences in ADFI, BW, and backfat changes, and growth of piglets during lactation. Plasma Trp concentration was greater for the sows allocated to the slight excessive Trp diet than for the sows allocated to the suboptimal Trp diet (P < 0.05). Plasma glucose, NEFA, and urea profiles during the meal tests were not affected by the dietary treatment. At d 3 of lactation, the insulin concentration at 105 (P = 0.03) and 120 min (P = 0.04) after meal intake was less for the sows allocated to the slight excessive Trp diet than for the sows allocated to the suboptimal Trp diet. On d 10 of lactation, the glucose half life (P = 0.03) and the time needed to reach 25% of the area under the insulin curve (P = 0.04) during the tolerance test were less for the sows allocated to the slight excessive Trp diet than for the sows allocated to the suboptimal Trp diet. The glucose infusion rate during euglycemic hyperinsulinemic clamps was similar in the 2 Trp groups of sows. Irrespective of the dietary treatment, the ADFI of the sows was negatively related to the glucose half life during the glucose tolerance test and positively related to the glucose infusion rate during the clamp (P < 0.05). This relationship observed with the tests performed during early lactation was already found with the tests performed during late pregnancy (P < 0.02). Present findings indicate that a dietary Trp supply of 0.26% does not increase feed intake in lactating primiparous sows. This result indicates that the interest in a Trp supplementation during the peripartum period can be questioned. Irrespective of the dietary treatment, the reasons why sows with similar rearing conditions develop different rates of insulin resistance during pregnancy remain to be elucidated.

Effects of Dietary Supplementation of β‐hydroxy‐β‐methylbutyrate on Sow Performance and mRNA Expression of Myogenic Markers in Skeletal Muscle of Neonatal Piglets

“…In this regard, some studies have demonstrated that the feed intake of sows during lactation is negatively related to the insulin‐resistance during the periparturient period (Mosnier et al. ), moreover, in the present study, the sows fed HMB diet had higher fasting plasma glucose content than sows fed the control diet at days 2 and 28 of lactation (Table ), which provided further evidence for the increased insulin resistance. Therefore, the reduced feed intake of sows during lactation in the HMB group might be associated with the increased insulin resistance, and the underlying mechanism of which remains to be elucidated further.…”

Long-Lasting Effect of Perinatal Exposure to L-tryptophan on Circadian Clock of Primary Cell Lines Established from Male Offspring Born from Mothers Fed on Dietary Protein Restriction

“…The daily food intake of rat pups measured between Day 39 and Day-42 showed that the food consumption of the LP group is lower than the CP group irrespectively of a supplementation by L-tryptophan (Figure S1) . These observations on nursing rats with offspring are similar to results obtained in lactating sows [16]. In addition, the relative food intake was higher for the LP group during the night cycle but the relative intakes of both groups were similar during the light cycle ( Figure 2 ).…”

“…From human studies, we also know that the circadian rhythm of tryptophan in breast milk affects the rhythms of 6-sulfatoxymelatonin and sleep in newborn [12], [13] and that infant formulas supplemented in L-tryptophan during the night can alter the expression of genes in cerebellum of nursing rat neonates [14]. It has been found that acute supplementation with tryptophan show transitory increase of melatonin plasma levels [15] as well as alteration in insulin secretion [16].…”

Effects of konjac flour inclusion in gestation diets on the nutrient digestibility, lactation feed intake and reproductive performance of sows

“…The transition from gestation to lactation is characterized by physiological and metabolic changes, such as a progressive decrease in insulin sensitivity during late gestation and lactation (Pere et al, 2000;Pere and Etienne, 2007). During lactation, insulin resistance is negatively correlated with the feed intake of sows (Van der Peet-Schwering et al, 2004;Mosnier et al, 2010). Several studies have shown that soluble dietary fiber can improve insulin sensitivity in mice or rats (Song et al, 2000;Isken et al, 2010).…”