Dietary Kluyveromyces marxianus hydrolysate alters humoral immunity, jejunal morphology, cecal microbiota and metabolic pathways in broiler chickens raised under a high stocking density.

This study investigated the impact of dietary supplementation with hydrolyzed yeast (Kluyveromyces marxianus) on growth performance, humoral immunity, jejunal morphology, cecal microbiota and metabolic pathways in broilers raised at 45 kg/m2. A total of 1,176 mixed sex 1-day-old Ross 308 broilers were distributed into 42 pens and randomly assigned to either the control group, the control + 250 g hydrolyzed yeast (HY)/ton, 250HY group, or the control + 500 g HY/ton, 500HY group for 42 d. HY did not affect growth performance. However, HY reduced (P < 0.05) mortality at 25 to 35 d. Dietary HY lowered the heterophil/lymphocyte ratio and enhanced the villus height/crypt depth ratio and Newcastle disease titer (P < 0.05). Compared with HY250 and the control, HY500 upregulated (P < 0.05) IL-10. HY enhanced the α diversity, inferring the richness and evenness of the ceca microbiota. HY500 had greater ß diversity than the control (P < 0.05). Six bacterial phyla, namely, Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria, Verrucomicrobia, and Cyanobacteria, were found. The relative abundance of Firmicutes was greater in the HY500 treatment group than in the HY250 and control groups. HY decreased the abundance of Actinobacteria. HY supplementation altered (P < 0.05) the abundance of 8 higher-level taxa consisting of 2 classes (Bacilli and Clostridia), 1 order (Lactobacillales), 1 family (Streptococcaceae), and five genera (Streptococcus, Lachnospiraceae_uc, Akkermansiaceae, PACO01270_g, and LLKB_g). HY500 improved (P < 0.05) the abundance of Bacilli, Clostridia, Lactobacillales, Streptococcaceae, Streptococcus, PACO01270_g, and Lachnospiraceae_uc, while HY250 enhanced (P < 0.05) the abundance of Akkermansiaceae and LLKB_g. HY improved the abundance of Lactobacillus and Akkermansia spp. Minimal set of pathway analyses revealed that compared with the control, both HY250 and HY500 regulated 20 metabolic pathways. These findings suggest that dietary K. marxianus hydrolysate, especially HY500, improved humoral immunity and jejunal morphology and beneficially altered the composition and metabolic pathways of the cecal microbiota in broilers raised at 45 kg/m2.

Effect of trehalose supplementation on growth performance and intestinal morphology in broiler chickens.

Trehalose (Tre) is a natural disaccharide. A laboratory-scale investigation showed that Tre supplementation increased the growth rate in juvenile chicks, possibly via the improvement of innate intestinal immune responses. In this study, two trials were conducted to evaluate the growth-promoting effect of Tre supplementation in broiler chickens. In experiment-1, two thousand day-old male and female broiler chicks (Ross) were fed 0 (control), 0.25, 0.50, and 0.75% Tre-supplemented pellet-form diets from d 1-17, and subsequently, they were provided grower (d 18-30) and finisher (d 31-37) diets without Tre supplementation. Over the trial period, there was no significant difference in body weight (BW), feed intake and feed conversion ratio (FCR) between chickens in the control and Tre-fed groups. Tre treatment increased villus height (VH)/crypt depth (CD) ratio and villus surface in jejunum; decreased CD and increased VH/CD ratio in ileum on d 17, when these results were compared to the control group. In experiment-2, two hundred day-old female broiler chicks were fed an antibiotics-free and mash-form diet supplemented with 0.5% Tre from d 1-21, before being fed a non-supplemental diet until d 43. There was no difference in BW on d 21 between the control and Tre-0.5% groups; however, from d 22-43, Tre-0.5% group showed significantly higher BW gain and lower FCR compared to the control group. From these results, we suggest that Tre feeding can be beneficial for intestinal morphology and growth performance in broiler chickens. However, these outcomes did not occur in parallel owing to the different feeding conditions observed.

Krill Meal Enhances Antioxidant Levels and n-3 Fatty Acid Content of Egg Yolk from Laying Hens Fed a Low-Pigment Diet.

This study was conducted to determine effects of krill meal supplementation on production performance, egg quality, antioxidant substances, and fatty acid composition of egg yolk from hens fed a low-pigment diet. A total of 640 laying hens (Lohmann Brown), which were each 25 weeks old, were divided into 4 dietary treatment groups. Each treatment consisted of 8 replications with 20 laying hens per replication. The treatments were corn-soybean meal basal diet (CS), CS with 7.5% cassava meal (low-pigment; LP), and LP with 1.5 or 3% krill meal. All dietary treatments were formulated to be isocaloric (2,750 kcal/kg metabolizable energy) and isonitrogenous (17.5% crude protein). Birds were raised in an evaporative cooling system house for 8 weeks (25-33 weeks of age). Water was provided ad libitum and feed was provided according to breed requirement recommendations. The LP diets supplemented with krill meal had no effect on production performance and egg quality compared to those of the CS group (P>0.05). However, the LP diet caused a significant reduction in yolk color score, and astaxanthin, vitamin A, and vitamin E contents of egg yolk (P<0.05). However, the contents of these nutrients increased as the level of krill meal was increased in the diets (P<0.05). The highest yolk color score, and astaxanthin, vitamin A, and vitamin E contents were observed in laying hens fed 3% krill meal (P<0.05). The LP diet had no effect on n-3 fatty acid content; however, a significant reduction in the content of n-6 fatty acids, especially linoleic acid was observed (P<0.05). Further reduction occurred when higher level of krill was used in the diets (P<0.05). An increase in krill meal level significantly increased docosahexaenoic acid but not linolenic acid content of egg yolk. Krill meal, therefore, could be used to produce docosahexaenoic acid and antioxidant enriched eggs.

Effect of enzymatic hydrolysate of cottonseed protein supplementation on growth performance and intestinal health of nursery pigs in Thailand.

This study investigated the effects of enzymatic hydrolysate of cottonseed protein (EHCP) supplementation on the growth performance and intestinal health of nursery pigs in Thailand. A total of 180 newly weaned piglets were randomly allocated to 3 groups with 6 replicates in each group and 10 piglets per replicate. Nursery pigs were fed three diets containing 0, 1%, and 1.5% EHCP for 28-63 days of age. The results indicated that 1% EHCP supplementation increased average daily feed intake (ADFI) and average daily gain (ADG) and decreased feed conversion rate (FCR) in the numerical, suggesting that appropriate EHCP supplementation could numerically improve growth performance of nursery pigs in Thailand. Moreover, 1% EHCP supplementation significantly decreased intestinal crypt depth and diarrhea incidence and increased intestinal villus height to crypt depth ratio and fecal consistency, suggesting that optimum EHCP supplementation could improve intestinal morphology and decreased diarrhea incidence of nursery pigs in Thailand. Furthermore, 1% EHCP supplementation significantly improved intestinal glutathione (GSH) level and superoxide dismutase (SOD) activity and indicated that optimal EHCP supplementation could improve intestinal antioxidant capacity of nursery pigs in Thailand. Optimum EHCP supplementation numerically increased growth, significantly decreased diarrhea incidence, significantly improved intestinal morphology and antioxidant capacity of nursery pig in Thailand.

Correction to: Effect of enzymatic hydrolysate of cottonseed protein supplementation on growth performance and intestinal health of nursery pigs in Thailand.

In the originally published article, the sentence "It was prepared from carefully selected soybean meal and was processed by enzymatic hydrolysis into small peptide." in the section Materials and methods was incorrect.