Apparent jejunal amino acid digestibility, gut morphology, and the expression of intestinal amino acid transporters in pigs fed protein or free amino acids.

Dietary amino acids (AA) supplied as protein or in free form are not only digested and absorbed at different rates but can also induce differences in the intestinal physiology of pigs. We compared the apparent jejunal AA digestibility, intestinal morphology, and gene expression of AA transporters of pigs fed diets providing different forms of AA. Thirty growing pigs (33.7 ± 4.1 kg) were fed one of three experimental diets that provided AA either as protein from feather meal (INT), as free AA and small peptides obtained by extensive acid hydrolysis of feathers (HYD), or as a mix of individual purified AA with the same AA profile as HYD (FAA). Pigs were fed the same quantity of feed, energy, and AA. After 14 d, pigs were slaughtered 3 h after feeding a meal with indigestible markers. Digesta and tissue were collected from different sections of the small intestine. Jejunal digesta was used to measure apparent jejunal digestibility of AA. Samples of the duodenum, jejunum, and ileum were used to measure intestinal morphology and the gene expression of intestinal AA transporters. The measured apparent jejunal digestibility of AA of INT was lower compared to HYD and FAA (P < 0.05). The apparent jejunal digestibility of Cys, Gly, His, Met, and Pro was lower for FAA compared to HYD (P < 0.05). This may be due to the small peptides in HYD, which are absorbed faster than individual AA. The villi area in the ileum of HYD fed pigs was the highest (P < 0.05) among the treatments, which may be associated with the reabsorption of endogenous proteins, which occurs mostly in the ileum. In the duodenum, HYD and FAA had lower expression of PepT1 (P < 0.01) probably due to the rapid transit time of digesta compared to INT fed pigs. Pigs fed HYD expressed more ASCT2 (P = 0.02) and CAT-1 (P = 0.04) in the jejunum compared to the pigs fed the other diets. The expression of these transporters along the intestine depended on the relative abundance of readily absorbable dietary AA. Results showed that dietary AA form can have an influence on the morphology and on the expression of different AA transporters along the different sections of the small intestine.

The amino acids (AA) in the diet of pigs are usually supplied as a mix of proteins and free AA. Proteins need to be digested first before their constituent AA become available to the animal. Free AA, together with small peptides, are readily available without the need for digestion. Moreover, the different forms by which AA are supplied may also have an effect on intestinal physiology. In this experiment, pigs were fed different diets with the same AA profile but were provided either as protein, as free AA and small peptides originating from hydrolyzed protein, or as a mix of individual free AA. Results showed that feeding pigs free AA and/or small peptides resulted in higher apparent jejunal digestibility of AA compared to feeding proteins. Furthermore, the apparent jejunal digestibility of the AA of a hydrolyzed protein was higher than that of free AA. Providing diets with readily absorbable AA resulted in a higher surface area for absorption and an increase in the gene expression of AA transporters as opposed to proteins.

Effect of live yeast supplementation in sow diet during gestation and lactation on sow and piglet fecal microbiota, health, and performance.

Feeding probiotics like live yeast Saccharomyces cerevisiae var. boulardii (SB) in pig diets has been suggested to preserve health and reduce antibiotic use during critical periods like weaning. This study was conducted to determine whether SB added to the diet of sows during the last 2 mo of gestation and the 4 wk of lactation may contribute to support the health and performance of piglets before and after weaning through changes in sow physiology, milk composition, and fecal microbiota. Crossbred sows (n = 45) from parity 1 to 9 were allocated to two dietary treatments: Control (n = 23) and SB (n = 22). Sows in the SB group were fed the same standard gestation and then lactation diet as the Control sows but with the addition of SB at 1 × 109 colony-forming units/kg of feed. Piglets were weaned under challenging conditions consisting of mixing of litters, no pen cleaning, and a 2-h period of nonoptimal temperature exposure. Blood and feces were collected from sows on days 28 and 113 of gestation and days 6 (feces only) and 28 of lactation, and from piglets on days 6 (feces) and 28 of lactation and day 5 after weaning. Colostrum was collected during parturition and milk on day 6 of lactation. Supplementation of sow diets with SB influenced the fecal microbiota of the sows and their piglets. Five days after weaning, the alpha-diversity was lower (P < 0.05) in piglets from SB sows than in piglets from Control sows. Analysis of microbiota with partial least square discriminant analysis discriminated feces from SB sows from that of Control sows at 110 d of gestation (29.4% error rate). Piglet feces could also be discriminated according to the diet of their mother, with a better discrimination early after birth (day 6 of lactation) than after weaning (day 5 postweaning, 3.4% vs. 12.7% error rate). Five days after weaning, piglets had greater white blood cell count, plasma haptoglobin concentration, and oxidative stress than before weaning (P < 0.001). Nevertheless, SB supplementation in sow diets had no effect (P > 0.05) on most of health criteria measured in blood and growth performance of piglets during lactation and the postweaning period. Moreover, dietary supplementation of SB to sows did not elicit any changes (P > 0.05) in their reproductive performance, metabolic and health status, nor in the concentration of immunoglobulins and nutrients in colostrum and milk. In the present experimental conditions, feeding SB to sows influenced sow and piglet microbiota with no consequences on their health and performance.

Feeding live yeast Saccharomyces cerevisiae var. boulardii (SB) in pig diets is recommended to promote a better health and reduce antibiotic use during critical periods like weaning. Our study was conducted to determine if SB added to the diet of sows during the last 2 mo of gestation and the 4 wk of lactation may contribute to support the health and performance of their piglets before and after weaning. We hypothesized that live SB supplementation to the sows may help improve the health and metabolic status of the sows and consequently the quality of milk and microbiota provided to the piglets. Supplementation of sow diet with SB during gestation and lactation induced modifications in the fecal microbiota of sows and their piglets. For piglets, the effects of SB fed to their mother were still observed 5 d after weaning. These modifications were, however, associated with changes neither in piglet ability to cope with the stress of weaning nor in milk nutritional and immune composition.