Beneficial effects of probiotics on the pig production cycle: An overview of clinical impacts and performance.

In pig nutrition, antibiotics are used to promote growth and/or to treat diseases in order to improve animal performance. However, due to the potential risk of cross selective pressure for antibiotic resistance among bacterial pathogens, the development of new nutritional additives is needed. Among them, probiotics are of great interest since they could improve the immune response, maintain animal intestinal health, and improve nutritional efficiency. Studies with probiotics have also demonstrated their antimicrobial effects on several pathogenic strains, emphasizing that the form of administration can enhance the beneficial effects. In view of the promising advances in probiotic research, it is opportune to highlight their capacity to modulate health and improve performance at all stages of pig production. Therefore, in this review, we will discuss the benefits of probiotics on physiological, immunological, and clinical aspects during different stages of the pig's life cycle. Specifically, probiotics improve performance during pregnancy, parturition and lactation in sows, they can improve immunohematological parameters and defenses in the growing phase, they can influence the quality of meat in the finishing phase and can also help in the reduction of environmental pollutants.

Dietary supplementation with hydrolyzed yeast and its effect on the performance, intestinal microbiota, and immune response of weaned piglets.

The objective of this study was to evaluate the effects of autolyzed yeast on performance, cecal microbiota, and leukogram of weaned piglets. A total of 96 piglets of commercial line weaned at 21-day-old were used. The experimental design was a randomized block design with four treatments (diets containing 0.0%, 0.3%, 0.6%, and 0.9% autolyzed yeast), eight replicates, and three animals per pen in order to evaluate daily weight gain, daily feed intake, and feed conversion in periods of 0 to 15, 0 to 26, and 0 to 36 days. Quadratic effects of autolyzed yeast inclusion were observed on the feed conversion from 0 to 15 days, on daily weight gain from 0 to 15 days, 0 to 26 days and, 0 to 36 days, indicating an autolyzed yeast optimal inclusion level between 0.4% and 0.5%. No effect from autolyzed yeast addition was observed on piglet daily feed intake, cecal microbiota, and leukogram; however, i.m. application of E. coli lipopolysaccharide reduced the values ​​of total leukocytes and their fractions (neutrophils, eosinophils, lymphocytes, monocytes, and rods). Therefore, autolyzed yeast when provided at levels between 0.4% and 0.5% improved weaned piglets' performance.

Evaluation of growth performance and gastro-intestinal parameters on the response of weaned piglets to dietary organic acids

ABSTRACT Two experiments (E) were carried out to evaluate the effects of fumaric acid and an acidifier blend [composed by calcium formate, calcium lactate and medium-chain fatty acids (capric and caprylic)] in piglet diets containing colistin (40 ppm) or halquinol (120 ppm) on performance, diarrhea incidence (E1), organs relative weight, pH values, intestinal morphometry and microbiota (E2). In E1, 192 and E2, 24 piglets weaned at 21-day-old were randomly assigned to blocks with 2x2 factorial arrangement of treatments [absence or presence of fumaric acid x absence or presence of acidifier blend], six replicates of eight (E1) and one piglet per pen (E2). For E1, the treatments were control (CD): no acidifier product + 40 ppm of colistin, FA: fumaric acid in absence of acidifier blend, AB: acidifier blend in absence of fumaric acid and, AF+AB: presence of fumaric acid and acidifier blend. For E2, the pre-starter I diet were used and the same treatments as E1 evaluated. No treatment effects (P>0.05) were observed on performance, diarrhea incidence (E1), gut pH values and duodenum morphometry of piglets (E2). However, the addition of AB increased (P<0.05) large intestine relative weight and, FA addition decreased (P<0.05) pancreas relative weight, jejunum villi height and, total coliform and E. coli counts in cecum. The inclusion of FA and AB in diets containing colistin or halquinol did not improve performance, although FA exerted an inhibitory effect on cecum microbiota.

Dietary glutamine, glutamic acid and nucleotide supplementation accelerate carbon turnover (δ13C) on stomach of weaned piglets.

The use of stable isotope analysis as a tool for characterization of carbon turnover (δ13C) in piglet's tissues by tracing its feeding system has drawn attention. Thus, this study aimed at evaluating the influence of dietary glutamine, glutamic acid and nucleotides supplementation on carbon turnover in fundic-stomach region of weaned piglets at an average age of 21 days. The diets consisted of additive-free diet - control (C); 1% glutamine (G); 1% glutamic acid (GA) and 1% nucleotides (Nu). At weaning day (day 0: baseline), 3 piglets were slaughtered to quantify the δ13C of stomach. The remaining 120 piglets were blocked by weight and sex, randomly assigned to pens with 3 piglets slaughtered per treatment at days 1, 2, 4, 5, 7, 9, 13, 20, 27 and 49 after weaning in order to verify the fundic-stomach isotopic composition by treatments. Samples were analyzed in terms of 13C/12C ratio by mass spectrometry and converted to relative isotopic enrichment values (δ13C ‰) used to plot the first order exponential curves over time using OriginPro 8.0 software. The inclusion of glutamine, glutamate and nucleotides in piglet's diets has accelerated the carbon turnover in stomach during the post-weaning period, demonstrating also that glutamate has guaranteed fastest 13C incorporation rate on fundic-stomach region and pH-lowering. Besides that, stable isotopes technique (δ13C) has proved to be an important methodology to determine the time-scales at which piglets shift among diets with different isotopic values, characterizing the trophic effects of additives and the phenotypic flexibility of stomach.

Effects of ß-(1→3,1→6)-D-glucan and density of diets on the blood profiles of immunologically challenged weaned piglets.

An experiment was conducted to evaluate the effects of two levels of the ß-(1→3,1→6)-D-glucan (0 and 500 ppm) from yeast Saccharomyces cerevisiae and two levels of energy (3300 and 3450 kcal ME kg(-1)) on the hematological, immunological and, biochemical profiles of thirty-six 21-days-old weaned piglets, challenged with 150 µg kg(-1) of BW lipopolysaccharide (LPS) from Escherichia coli serotype 055:B5. The experimental design was a randomized complete block design in a 2×2 factorial arrangement with nine replicates per treatment and, one animal per experimental unit. The data were analyzed in accordance with the multivariate analysis procedure of SAS and, the treatment means of parametric and non-parametric data were compared by Bonferroni's test (P<0.05) and, by Dunn's test (P<0.05), respectively. The data of the blood profiles of alanine aminotransferase, alkaline phosphatase and, creatinine showed that LPS did not cause kidney or liver damage in the animals. The addition of beta-glucan in the diets did not prove the robustness of its effect and biological relevance when provided with low nutrient-density. However, its addition combined with the high-nutrient-density diets showed less marked hypoglobulinemia in piglets, which may have contributed to the decreasing of the synthesis of inflammatory mediators.