No abstract

Postprandial changes in plasma concentrations of GH, insulin, IGF-I, leptin and metabolites were compared between young Holstein bull calves fed with milk alone (control group) and with milk+5 -uridylic acid (UMP) (UMP group). UMP (2 g/day) was given with milk at 0830 h and 1530 h for 11 days from the 4th to the 14th day after birth. The perirenal fat weight was significantly lower in the UMP group than in the control group, but there was no significant difference in the weights of the liver, spleen and heart between the groups. Basal GH concentrations in the UMP group were slightly higher, but the postprandial increase in plasma insulin level and the area under the curve for insulin in the UMP group were significantly lower than those in the control group.There was no significant difference in IGF-I levels between the groups. In addition, the postprandial glucose concentrations were lower in the UMP group as reflected by the insulin level, and nonesterified fatty acid concentrations were not different. In the muscle (M. longissimus thoracis) sampled at 14 days of age, the triacylglycerol (TAG) content was significantly greater but glycogen content was significantly lower in the UMP group than in the control group. From these results, we have concluded that feeding 5 -UMP at 2 g/day for 11 days significantly alters TAG accumulation in the body and plasma concentrations of GH and insulin in young bull calves.

Two experiments were conducted to determine the effect of dietary xylitol concentration on growth performance, plasma (alpha1 acid glycoprotein (AGP), nitrite, and Fe concentration in male broiler chicks during immunological stress. Ten-day-old chicks were fed a corn-soybean diet containing 15% glucose and 6% xylitol or 15% xylitol with identical metabolizable energy and crude protein content for 12 d in Experiment 1. In Experiment 2, 12-d-old chicks were fed either the 15% glucose or 6% xylitol diet for 7 d. During the final 6 d of each experiment, half of the birds fed each diet were injected intraperitoneally with Escherichia coli lipopolysaccharide (LPS; 0127:B8) on Days 1, 3, and 5 and with Sephadex-G50 superfine on Days 2 and 4 to stimulate the immune system. The xylitol diets partially prevented reductions in body weight gain, feed intake, and feed efficiency caused by LPS and Sephadex injections, but the glucose diet did not. The injections of LPS and Sephadex increased plasma AGP and nitrite concentrations. Plasma AGP concentration on Days 2 and 6 in chicks fed the xylitol diets did not differ from that of chicks fed the glucose diet in both experiments. Nitric oxide production estimated by plasma nitrite concentration following immunological stress did not differ due to dietary treatments in Experiment 2. The LPS and Sephadex resulted in decreased plasma Fe concentration on Day 6 in Experiment 1 in chicks fed glucose but not xylitol. These results indicate that a beneficial effect of dietary xylitol on growth is obtained with 6% xylitol given to chicks 1 d before stimulating the immune system.

No abstract