Effect of colostral fat level on fat deposition and plasma metabolites in the newborn pig.

The effects of colostral fat level on fat deposition and plasma concentrations of glucose, insulin, and free fatty acids (FFA) were determined in 28 newborn pigs during the first postnatal day. Soon after birth, pigs were allotted to four treatments groups. Group 1 was killed at birth. The remaining pigs were fed intragastrically sow colostrum that contained high (10.2%; HFC), normal (4.8%; NFC) or low (1.0%; LFC) levels of total fat at the rate of 15 to 18 g/kg birth weight at 65- to 70-min intervals. A total of 21 feedings was provided and pigs were killed 1 h after the last feeding. Body fat deposition increased linearly (P less than .01) with the amount of ingested fat by .32 (+/- .04) g per 1-g increase in fat intake. Fatty acid composition of the pigs changed toward that of the colostrum with increased fat in colostrum. More liver glycogen was lost (P less than .01) in pigs given LFC. Plasma concentrations of glucose and insulin were similar in pigs fed HFC and NFC. After the 11th feeding (14 h postnatal), LFC resulted in lower plasma glucose concentrations (P less than .05) than HFC or NFC. Plasma insulin concentrations also were lower in pigs fed LFC. Plasma FFA concentrations remained unchanged in pigs fed LFC but increased with both fat content in colostrum (P less than .05) and time (P less than .05) in the other two groups. Colostral fat plays a major role in the supply of energy and in glucose homeostasis in the neonatal pig.

Diet modifies elastase I and II activities and mRNA levels during postnatal development and weaning in piglets.

Little information is available on the expression of pancreatic elastase I and II, despite their role in protein milk digestion. We studied the developmental changes and the effects of diet composition on both elastase I and II expression in suckled and weaned piglets. We measured their activities and levels of their corresponding mRNA. Forty-two piglets were assigned to seven groups according to age and diet. Piglets were slaughtered at birth (Group 1), or suckled up to 13 d (Group 2) or 21 d (Group 3), fed a milk substitute from 14 to 21 d (Group 4) or to 56 d (Group 7), suckled up to 21 d and then fed a dry starter up to 56 d (Group 5), or fed a milk substitute from 14 to 21 d and then a dry starter up to 56 d (Group 6). At 21 d pancreatic function was not modified by the source and the form of milk consumed. The specific activity of elastase II was maximum at birth and declined sharply thereafter, whereas that of elastase I markedly increased after weaning. The presence of milk protein in the diet did not prevent the sharp decrease in elastase II activity observed with age. During the 13 d period of suckling sow's milk, the mRNA patterns indicated that the regulation was at the mRNA and post-transcriptional levels, whereas after weaning and depending on the source of dietary protein, it was essentially translational and/or post-translational. Taken together, our results provide evidence of the early expression of elastase I and II genes that could enhance protein digestion. It seems that elastase II might be a predominant pancreatic protease during the milk-feeding period, whereas elastase I might be related to weaning.

Method of measurement of pancreatic elastase II activity and postnatal development of proteases in human duodenal juice and bovine and porcine pancreatic tissue.

A specific method for pancreatic elastase II activity analysis was developed. True elastase II activity could be discriminated from that of elastase I and chymotrypsin. The postnatal development of four pancreatic proteases in the duodenal juice of children and in the pancreatic homogenates of calves and piglets was measured. The study was carried out on patients without (14 children) and with (5 children) pancreatic insufficiency. Calves and piglets were either milk-fed or weaned until slaughter at different ages. Profiles of enzyme development were globally similar in milk-fed piglets and calves, while in children without pancreatic insufficiency, no significant change was observed between 4 and 168 months. In children with pancreatic insufficiency, enzyme activity was low. In animals, elastase II and chymotrypsin activities were maximal at birth, decreased with age, and probably were associated with the digestion of milk protein. In contrast, elastase I and trypsin activities increased markedly after weaning in connection with the intake of solid food.