Starving for nutrients: anorexia during infection with parasites in broilers is affected by diet composition

Growth performance and immune response of broilers during active Eimeria infection are modified by dietary inclusion of canola meal or corn-DDGS in reduced-protein corn-soybean meal diets

The objective of this experiment was to study the effects of partial replacement of soybean meal (SBM) with canola meal (CM) or corn-distillers' dried grains with solubles (cDDGS) in reduced-protein (RP) diets for Eimeria-infected broilers. A total of 1120 broiler chicks were distributed in a 4 × 2 (4 diets × with or without infection) factorial arrangement with 7 replicates per treatment and 20 birds per replicate. The 4 diets, fed between d 7 and 42, were (i) a standard diet with crude protein at 200 g/kg (SP); (ii) a RP (crude protein at 160 g/kg) corn-SBM diet (RP-SBM); (iii) a RP diet in which 80 g/kg CM replaced 60 g/kg SBM (RP-CM); and (iv) a RP diet in which 100 g/kg cDDGS replaced 50 g/kg SBM (RP-cDDGS). On d 15, birds were infected with mixed Eimeria (+E) oocysts. Birds and feed were weighed at intervals for growth performance, and samples for immunology responses were collected on d 21. The results showed as follows: 1) during the acute infection phase, diet × Eimeria infection was shown by the diets having no effect in the uninfected group. In contrast, the RP-SBM diet tended to produce higher (P < 0.10) weight gain among the infected birds. The d 42 body weight was greater (P = 0.001) for the uninfected birds. 2) There was a significant diet × Eimeria infection on bile anti-Eimeria immunoglobulin A (IgA) concentrations (P = 0.015), splenocyte proliferation, macrophage nitric oxide (NO) production (P < 0.001), and cecal tonsil interleukin (IL)-17 mRNA amounts (P < 0.001). Most of these responses were not influenced by the diets in the uninfected birds. However, among the infected birds, birds fed RP-SBM had higher (P < 0.05) bile IgA than those fed SP or RP-cDDGS. For the spleen, the interaction was that birds fed RP-SBM or RP-cDDGS diets had the highest or lowest NO production, respectively, and birds that received RP-SBM had greater (P < 0.05) splenic CD8+:CD4+ cell ratio than other diets. In conclusion, partial replacement of SBM with CM or cDDGS had only a marginal effect on d 42 body weight and FCR of the broiler chickens receiving the RP diets. In contrast, these had a negative impact on the immune responses of the broiler chickens.

Phase-specific outcmes of arginine or branched-chain amino acids supplementation in low crude protein diets on performance, nutrient digestibility, and expression of tissue protein synthesis and degradation in broiler chickens infected with mixed Eimeria spp

A 35-d study investigated the impact of dietary supplementation with Arginine (Arg) or branched-chain amino acids (BCAA) of broilers receiving low-protein diets whilst infected with mixed Eimeria species. All birds were given the same starter (d0-10) and finisher (d28-35) diets. The 4 grower diets used were a positive control (PC) with adequate protein (18.5%), a low protein diet (NC;16.5% CP), or the NC supplemented with Arg or BCAA. Supplemental AA was added at 50% above the recommended levels. The treatments were in a 4 × 2 factorial arrangement, with 4 diets, with or without Eimeria inoculation on d14. Birds and feed were weighed after inoculation in phases: prepatent (d14-17), acute (d18-21), recovery (d22-28), and compensatory (d29-35). Ileal digesta, jejunum, and breast tissue were collected on d21, 28, and 35. There was no diet × Eimeria inoculation on growth performance at any phase. Infected birds weighed less and consumed less feed (P < 0.05) in all phases. In the prepatent and acute phases, birds on the Arg diets had higher weight gain (P < 0.05) and lower FCR, similar to PC, when compared to NC and BCAA-fed ones. Infection reduced AA digestibility on d21 and 28 (Met and Cys). However, birds that received supplemental AA had higher digestibility (P < 0.05) of their respective supplemented AA on d 21 only. Infected birds had lower (P < 0.05) BO + AT and higher PEPT1 expression on d21. There was a diet × Eimeria interaction (P = 0.004) on gene expression at d28; 4EBP1 genes were significantly downwardly expressed (P < 0.05) in birds fed Arg diet, irrespective of infection. Infected birds exhibited an upward expression (P < 0.05) of Eef2 on d21 and d28 but experienced a downward expression on d35. Supplemental Arg and BCAA had variable effects on growth performance, apparent ileal AA digestibility, and genes of protein synthesis and degradation, but the effect of Arg on promoting weight gain, irrespective of the Eimeria challenge, was more consistent.

Effects of methionine supplementation in a reduced protein diet on growth performance, oxidative status, intestinal health, oocyst shedding, and methionine and folate metabolism in broilers under Eimeria challenge

BACKGROUND

This study investigated effects of different methionine (Met) supplementation levels in a reduced protein diet on growth performance, intestinal health, and different physiological parameters in broilers under Eimeria challenge. A total of 600 fourteen-day-old Cobb500 male broilers were challenged with E. maxima, E. tenella, and E. acervulina, and randomly allocated in a 2 × 5 factorial arrangement. Birds received normal protein diets (20% crude protein, NCP) or reduced protein diets (17% crude protein, LCP), containing 2.8, 4.4, 6.0, 7.6, and 9.2 g/kg of Met.

RESULTS

On 6 and 9 days post inoculation (DPI), increasing Met level linearly improved the growth performance (P < 0.05). Total oocyst shedding linearly increased as Met level increased (P < 0.05). Duodenal villus height (VH):crypt depth (CD) in the LCP groups were higher on 6 DPI (P < 0.01) while lower on 9 DPI (P < 0.05) compared to the NCP groups. Jejunal CD and duodenal VH:CD changed quadratically as Met level increased (P < 0.05). On 6 DPI, liver glutathione (GSH) and glutathione disulfide (GSSG) linearly increased as Met level increased (P < 0.05). On 9 DPI, GSSG quadratically increased, whereas GSH:GSSG quadratically decreased as Met levels increased (P < 0.05). The expression of amino acid transporters linearly decreased as Met level increased (P < 0.05). The expression of zonula occludens 2 and claudin-1 linearly increased on 6 DPI whereas decreased on 9 DPI as Met level increased (P < 0.05). The expressions of cytokines were lower in the LCP groups than the NCP groups (P < 0.05). Interaction effects were found for the expression of IL-10 and TNFα on 6 DPI (P < 0.05), where it only changed quadratically in the NCP group as Met level increased. The expression of Met and folate metabolism genes were lower in the LCP groups than the NCP groups on 9 DPI (P < 0.05). The expression of these genes linearly or quadratically decreased as Met level increased (P < 0.05).

CONCLUSION

These results revealed the regulatory roles of Met in different physiological parameters including oxidative status, intestinal health, and nutrient metabolism in birds fed reduced protein diet and challenged with Eimeria.

Supplementing low protein diets with methionine or threonine during mixed Eimeria challenge

We investigated the effects of supplementing low protein diets with methionine (Met) or threonine (Thr) during a mixed Eimeria (consisting of E. acervulina, E. maxima and E. tenella) challenge in broilers. All birds were fed the same starter diet (d1-9) and finisher diet (d28-35) which met Cobb 500 nutrient specifications. Birds were allocated to 1 of 4 dietary treatments from d9 to 28: a standard protein diet (19% CP); a low protein diet (16% CP); or the low protein diet supplemented with Met or Thr at 50% above recommendations. On d14, half of the birds were challenged, and half of the birds were unchallenged. From d14 to 28, feed intake was recorded daily and BW every 3 or 4 d. Oocyst excretion was measured daily from d18 to 27. On d21 and 28, 3 birds per pen were euthanized to assess nutrient digestibility, cytokine expression and intestinal histology. During the acute stage of the challenge, challenged birds reduced ADFI and ADG (P < 0.05). In the pre-patent and recovery stages, birds given the 16% CP diets increased ADFI (P < 0.05), meanwhile there were no differences in ADG in these stages (P > 0.05). Nutrient digestibility was reduced in challenged birds in the acute stage (P < 0.05) but tended to be greater than in unchallenged birds during the recovery stage. There was no significant effect of diet on oocyst excretion or intestinal histology (P > 0.05). Interactions were observed between diet and challenge on IL-10 and IL-21 expression in the cecal tonsils during the acute stage of the challenge (P < 0.05), due to reduced IL-10 expression in challenged Thr birds and greater IL-21 expression in challenged Met birds. Supplementation with Thr or Met had limited effects on the outcomes of a mixed Eimeria challenge but provides benefits to the host by enhancing their immune response.

Lactiplantibacillus plantarum and Saccharomyces cerevisiae-Fermented Coconut Water Alleviates Dextran Sodium Sulfate-Induced Enteritis in Wenchang Chicken: A Gut Microbiota and Metabolomic Approach

In order to investigate the potential mechanisms of probiotic-fermented coconut water in treating enteritis, this study conducted a comprehensive analysis of the effects of probiotic intervention on the recovery from Dextran Sodium Sulfate-induced acute enteritis in Wenchang chicks. The analysis encompassed the assessment of growth performance, serum indicators, intestinal tissue structure, and metagenomic and metabolomic profiles of cecal contents in 60 Wenchang chicks subjected to intervention. This approach aimed to elucidate the impact of probiotic intervention on the recovery process from acute enteritis at both the genetic and metabolic levels in the avian model. The results revealed that intervention with Saccharomyces cerevisiae Y301 improved the growth rate of chicks. and intervention with Lactiplantibacillus plantarum MS2c regulated the glycerophospholipid metabolism pathway and reshaped the gut microbiota structure in modeling chicks with acute enteritis, reducing the abundance of potentially pathogenic bacteria from the Alistipes and increasing the abundance of potentially beneficial species from the Christensenellaceae. This intervention resulted in the production of specific gut metabolites, including Gentamicin C and polymyxin B2, recognized for their therapeutic effects on acute enteritis. The combined intervention of S. cerevisiae Y301 and L. plantarum MS2c not only enhanced growth performance but also mitigated intestinal wall damage and increased the abundance of gut metabolites such as gentamicin C and polymyxin B2, thereby mitigating symptoms of enteritis. Furthermore, this combined intervention reduced the levels of serum immune markers, including IL-10, IL-6, TNF-α, IFN-γ, and D-lactic acid, thus mitigating intestinal epithelial cell damage and promoting acute enteritis recovery. This study provides crucial insights into the mechanisms of action of probiotics and probiotic-fermented coconut water in acute enteritis recovery, offering new perspectives for sustainable farming practices for Wenchang chicken.

Impacts of varying methionine to cysteine supplementation ratios on growth performance, oxidative status, intestinal health, and gene expression of immune response and methionine metabolism in broilers under Eimeria spp. challenge

A study was conducted to investigate effects of different methionine (Met) to cysteine (Cys) supplementation ratios (MCR) on growth performance, oxidative status, intestinal health, immune responses, and methionine metabolism in broilers under Eimeria challenge. A total of 720 male Cobb500 broilers (14-day-old) were allocated in a 2 × 5 factorial arrangement (5 diets, with or without challenge) with 6 replicates per treatment. The total sulfur amino acid concentrations were consistent across treatments meeting the breeder's recommendation, only MCR varied. The diets were labeled as MET100; MET75; MET50; MET25; and MET0, representing MCR of 100:0; 75:25; 50:50; 25:75; and 0:100, respectively. Data were analyzed by 2-way ANOVA and orthogonal polynomial contrast. Growth performance declined linearly or quadratically as MCR decreased (P < 0.01). On 6-day postinoculation (DPI), interaction effects (P < 0.01) were found; BW and body weight gain were lower in MET0 compared to the other treatments in the nonchallenged groups, whereas not in the challenged groups. On 6 and 9 DPI, serum total antioxidant capacity linearly decreased as MCR decreased (P < 0.05). Hepatic activities of glutathione peroxidase on 6 DPI and superoxide dismutase on 9 DPI changed quadratically as MCR decreased (P < 0.05). The digestibility of Met linearly decreased whereas the digestibility of Cys linearly increased as MCR decreased. The ileal crypt depth linearly decreased as MCR decreased (P < 0.01) on 6 DPI. The expression of transforming growth factor beta on 6 and 9 DPI, tumor necrotic factor alpha and interleukin 10 on 9 DPI changed quadratically as MCR decreased (P < 0.05). Eimeria challenge increased expression of Met adenosyltransferase and cystathionine gamma-lyase, whereas decreasing the expression of other Met metabolism genes (P < 0.01) on 6 DPI. Expression of Met metabolism genes linearly increased as MCR decreased (P < 0.05). In conclusion, different Met to Cys supplementation ratios exerted linearly or quadratically effects on the growth performance, oxidative status, intestinal health, and metabolism of Met in broiler chickens under Eimeria infection.

Responses of broilers challenged by Eimeria maxima fed with different levels of dietary balanced protein

This study aimed to evaluate the effects of different dietary balanced protein (BP) levels on the gut health, amino acid apparent ileal digestibility (AID), footpad dermatitis lesions, and litter quality in broiler chicks infected with Eimeria maxima. A total of 2400 male 14-day-old Cobb500 broilers were randomly allotted into 10 treatments with six replications containing 40 birds each in a factorial design of 5 × 2. The treatments consisted of five levels of BP (6.66%, 13.32%, 19.98%, 26.64%, and 33.3%), and broilers unchallenged (NCH) or challenged (CH). Broilers in the CH group received 1 mL of Eimeria maxima inoculum (7 × 103 sporulated oocysts/mL). Oocyst count in excreta, visual intestinal modifications score, morphology, and morphometrics of the ileum were used to determine gut health status. Additionally, amino acids and CP AID, litter quality, and footpad dermatitis were evaluated. An ANOVA and Kruskal-Wallis tests followed by post-hoc tests were performed. The oocyst count in the CH group increased with an increase in dieatary BP (P = 0.08). The incidence of intestinal modifications was higher in the CH group (P < 0.05) and increased with increasing dietary BP (P < 0.05). Morphometrics were impaired by the challenge (P < 0.05), and by the two highest BP levels (P < 0.05). Amino acids AID (methionine, methionine + cystine, arginine, and serine) were reduced by E. maxima challenge. An increase in dietary BP resulted in poor litter quality and high prevalence of of footpad dermatitis (P < 0.05). The E. maxima challenge and increased BP decreased gut health, litter quality, and cause a high incidence of footpad dermatitis.

Applications of Enteroendocrine Cells (EECs) Hormone: Applicability on Feed Intake and Nutrient Absorption in Chickens

This review focuses on the role of hormones derived from enteroendocrine cells (EECs) on appetite and nutrient absorption in chickens. In response to nutrient intake, EECs release hormones that act on many organs and body systems, including the brain, gallbladder, and pancreas. Gut hormones released from EECs play a critical role in the regulation of feed intake and the absorption of nutrients such as glucose, protein, and fat following feed ingestion. We could hypothesize that EECs are essential for the regulation of appetite and nutrient absorption because the malfunction of EECs causes severe diarrhea and digestion problems. The importance of EEC hormones has been recognized, and many studies have been carried out to elucidate their mechanisms for many years in other species. However, there is a lack of research on the regulation of appetite and nutrient absorption by EEC hormones in chickens. This review suggests the potential significance of EEC hormones on growth and health in chickens under stress conditions induced by diseases and high temperature, etc., by providing in-depth knowledge of EEC hormones and mechanisms on how these hormones regulate appetite and nutrient absorption in other species.

The effects of arginine and branched-chain amino acid supplementation to reduced-protein diet on intestinal health, cecal short-chain fatty acid profiles, and immune response in broiler chickens challenged with Eimeria spp

We investigated the effects of supplementing arginine (Arg) and branched-chain amino acids (BCAA) in broilers fed reduced-protein diets and challenged with Eimeria spp. All birds were fed the same starter diet meeting Cobb 500 nutrient specifications from d 1 to 9. Four grower diets: positive control (PC) with 20.0% crude protein (CP); reduced-protein negative control (NC) with 17.5% CP; or NC supplemented with Arg or BCAA at 50% above recommendations (ARG or BCAA) were fed to the birds from d 9 to 28. Birds were allocated in a 2 × 4 factorial arrangement (4 diets, each with or without challenge), with 8 replicates per treatment. On d 14, the challenge groups were orally gavaged with mixed Eimeria spp. Intestinal permeability was higher (P < 0.05) in NC than PC, whereas the permeability of ARG and BCAA groups did not differ significantly from PC. On d 28, a significant interaction (P < 0.01) was observed in CD8⁺: CD4⁺ ratios in cecal tonsils (CT), Eimeria challenge increased the ratios in all groups except for the ARG group. On d 21, a significant interaction was found for CD4⁺CD25⁺ percentages in CT (P < 0.01) that Eimeria challenge increased the percentages only in PC and NC groups. On d 21 and 28, significant interactions (P < 0.01) were found for macrophage nitric oxide (NO) production. In nonchallenged birds, NO was higher in the ARG group than other groups, but in challenged birds, NO was higher in both ARG and BCAA groups. On d 21, a significant interaction was found for bile anticoccidial IgA concentrations (P < 0.05) that Eimeria challenge increased IgA only in NC and ARG groups. The results suggest that a reduced-protein diet exacerbates the impact of the Eimeria challenge on intestinal integrity, but this could be mitigated by Arg and BCAA supplementations. Arginine and BCAA supplementations in reduced-protein diets could be beneficial for broilers against Eimeria infection by enhancing the immune responses. The beneficial effects of Arg supplementation tended to be more pronounced compared to BCAA supplementation.

Dietary Fiber Level Improve Growth Performance, Nutrient Digestibility, Immune and Intestinal Morphology of Broilers from Day 22 to 42

There are few systematic studies on the dietary fiber requirements of broilers in the late feeding stage, and there are not enough data to support this hypothesis. This experiment was conducted to examine the effects of dietary fiber level on growth performance, nutrient digestibility, immune function and intestinal morphology of broilers from day 22 to 42. A total of 480 one-day-old Arbor Acres broilers with half male and half female were randomly allocated into four groups, with eight replicates in each group and fifteen chickens in each replicate. The experimental period was 42 days. All broilers were fed a basal diet from 1 to 21 days. During the 22–42 day period, the four experimental groups were fed diets with soybean hulls as the fiber source, and crude fiber (CF) levels were 2%, 5%, 8% and 11%, respectively. The results showed that during the 29–42 day period, the average daily feed intake (ADFI) of broilers was higher in the 5% CF and 8% CF groups (p < 0.05), and during the 29–35 day period, the average daily gain (ADG) of broilers was higher and the ratio of feed and gain (F/G) of broilers was lower in the 5% CF and 8% CF groups (p < 0.05). The digestibility of crude protein (CP), ether extract (EE), CF, acid detergent fiber (ADF) and neutral detergent fiber (NDF) was higher in broilers of the 8% CF group (p < 0.05). The immunoglobulin A (IgA), immunoglobulin G (IgG) and immunoglobulin M (IgM) content of the plasma of broilers was higher in the 8% CF group (p < 0.05). The villus height (VH) of the duodenum, jejunum and ileum of broilers was higher, and the crypt depth (CD) was lower in the 8% CF group than that in the 2% CF group (p < 0.05). The ratio of VH and CD (V/C) of the duodenum and jejunum of broilers in the 8% CF group was higher than that in the 2% CF group (p < 0.05). The quadratic regression analysis showed that the optimum dietary CF level was 7–9%. In conclusion, under the conditions of this experiment, a diet of 7–9% CF may promote growth performance by improving the nutrient digestibility, immunity and intestinal morphology of broilers from day 22 to 42.