Graded levels of Eimeria challenge altered the microstructural architecture and reduced the cortical bone growth of femur of Hy-Line W-36 pullets at early stage of growth (0-6 wk of age)

Different methionine to cysteine supplementation ratios altered bone quality of broilers with or without Eimeria challenge assessed by dual energy X-ray absorptiometry and microtomography

Despite the acknowledged significance of nutrition in bone development, effects of methionine (Met) and cysteine (Cys) on bone quality remain under-researched, particularly during Eimeria challenge. We investigated the effects of different supplemental Met to Cys ratios (MCR) on bone quality of broilers under Eimeria challenge. A total of 720 fourteen-day old Cobb500 broilers were allocated into a 5 × 2 factorial arrangement. Five diets with Met and Cys supplemented at MCR of 100:0, 75:25, 50:50, 25:75, and 0:100 were fed to the birds with or without Eimeria challenge. Body composition was measured by dual energy x-ray absorptiometry, and the femur bone characteristics were assessed by microtomography. Data were analyzed by two-way ANOVA and orthogonal polynomial contrast. The results reaffirmed the detrimental effects of Eimeria challenge on bone quality. On 9 d post inoculation (DPI), significant interaction effects were found for whole body bone mineral content (BMC), lean tissue weight, and body weight (P < 0.05); in the nonchallenged group (NCG), these parameters linearly decreased as MCR decreased (P < 0.05). In the challenged group (CG), body weight and lean tissue weight were unaffected by MCR, and BMC linearly increased as MCR decreased (P < 0.05). For the cortical bone of femoral metaphysis on 6 DPI, bone mineral density (BMD) linearly increased as MCR decreased (P < 0.05). Bone volume to tissue volume ratio (BV/TV) in the CG linearly increased as MCR decreased (P < 0.05). On 9 DPI, BMC and TV linearly increased as MCR decreased (P < 0.05) in the NCG. BMD and BV/TV changed quadratically as MCR decreased (P < 0.05). For the trabecular bone of femoral metaphysis on 9 DPI, BV/TV, and trabecular number linearly increased as MCR decreased (P < 0.05) in the NCG. For the femoral diaphysis, BV, TV, BMC on 6 DPI, and BMD on 9 DPI linearly increased as MCR decreased (P < 0.05). In conclusion, this study showed that both Eimeria challenge and varying supplemental MCR could influence bone quality of broilers.

Effects of phytase supplementation on broilers fed with calcium and phosphorus-reduced diets, challenged with Eimeria maxima and Eimeria acervulina: influence on growth performance, body composition, bone health, and intestinal integrity

An experiment was conducted to evaluate the effects of phytase in calcium (Ca) and available phosphorous (avP)-reduced diet on growth performance, body composition, bone health, and intestinal integrity of broilers challenged with Eimeria maxima and Eimeria acervulina. A total of 672 14-day-old male broilers were allocated to a 2 × 4 factorial arrangement with 6 replicates per treatment and 14 birds per replicate. Two factors were Eimeria challenge and 4 dietary treatments: 1) a positive control (PC; 0.84% Ca and 0.42% avP); 2) a negative control (NC; 0.74% Ca and 0.27% avP); 3) NC + 500 FTU/Kg of phytase (NC + 500PHY); and 4) NC + 1,500 FTU/Kg of phytase (NC + 1500PHY). On d 14, birds in the Eimeria-challenged groups received a solution containing 15,000 sporulated oocysts of E. maxima and 75,000 sporulated oocysts of E. acervulina via oral gavage. At 5 d postinoculation (DPI), the challenged birds showed a higher (P < 0.01) FITC-d level than the unchallenged birds. While the permeability of the NC group did not differ from the PC group, the phytase supplementation groups (NC + 500PHY and NC + 1500PHY) showed lower (P < 0.05) serum FITC-d levels compared to the NC group. Interaction effects (P < 0.05) of Eimeria challenge and dietary treatments on feed intake (FI), mucin-2 (MUC2) gene expression, bone ash concentration, and mineral apposition rate (MAR) were observed. On 0 to 6 and 0 to 9 DPI, Eimeria challenge decreased (P < 0.01) body weight (BW), body weight gain (BWG), FI, bone mineral density (BMD), bone mineral content (BMC), bone area, fat free bone weight (FFBW), bone ash weight, bone ash percentage and bone ash concentration; and it showed a higher FCR (P < 0.01) compared to the unchallenged group. The reduction Ca and avP in the diet (NC) did not exert adverse effects on all parameters in birds, and supplementing phytase at levels of 500 or 1,500 FTU/Kg improved body composition, bone mineralization, and intestinal permeability, with the higher dose of 1,500 FTU/Kg showing more pronounced enhancements. There was an observed increase in FI (P < 0.01) when phytase was supplemented at 1,500 FTU/Kg during 0 to 6 DPI. In conclusion, results from the current study suggest that dietary nutrients, such as Ca and avP, can be moderately reduced with the supplementation of phytase, particularly in birds infected with Eimeria spp., which has the potential to save feed cost without compromising growth performance, bone health, and intestinal integrity of broilers.

Coccidiosis in Egg-Laying Hens and Potential Nutritional Strategies to Modulate Performance, Gut Health, and Immune Response

Avian coccidiosis, despite advancements in management, nutrition, genetics, and immunology, still remains the most impactful disease, imposing substantial economic losses to the poultry industry. Coccidiosis may strike any avian species, and it may be mild to severe, depending on the pathogenicity of Eimeria spp. and the number of oocysts ingested by the bird. Unlike broilers, low emphasis has been given to laying hens. Coccidiosis in laying hens damages the gastrointestinal tract and causes physiological changes, including oxidative stress, immunosuppression, and inflammatory changes, leading to reduced feed intake and a drastic drop in egg production. Several countries around the world have large numbers of hens raised in cage-free/free-range facilities, and coccidiosis has already become one of the many problems that producers have to face in the future. However, limited research has been conducted on egg-laying hens, and our understanding of the physiological changes following coccidiosis in hens relies heavily on studies conducted on broilers. The aim of this review is to summarize the effect of coccidiosis in laying hens to an extent and correlate it with the physiological changes that occur in broilers following coccidiosis. Additionally, this review tries to explore the nutritional strategies successfully used in broilers to mitigate the negative effects of coccidiosis in improving the gut health and performance of broilers and if they can be used in laying hens.

Aflatoxin B1 Impairs Bone Mineralization in Broiler Chickens

Aflatoxin B1 (AFB1), a ubiquitous mycotoxin in corn-based animal feed, particularly in tropical regions, impairs liver function, induces oxidative stress and disrupts cellular pathways, potentially worsening bone health in modern broilers. A 19-day experiment was conducted to investigate the effects of feeding increasing levels of AFB1-contaminated feed (<2, 75-80, 150, 230-260 and 520-560 ppb) on bone mineralization markers in broilers (n = 360). While growth performance remained unaffected up to Day 19, significant reductions in tibial bone ash content were observed at levels exceeding 260 ppb. Micro-computed tomography results showed that AFB1 levels at 560 ppb significantly decreased trabecular bone mineral content and density, with a tendency for reduced connectivity density in femur metaphysis. Moreover, AFB1 above 230 ppb reduced the bone volume and tissue volume of the cortical bone of femur. Even at levels above 75 ppb, AFB1 exposure significantly downregulated the jejunal mRNA expressions of the vitamin D receptor and calcium and phosphorus transporters. It can be concluded that AFB1 at levels higher than 230 ppb negatively affects bone health by impairing bone mineralization via disruption of the vitamin D receptor and calcium and phosphorus homeostasis, potentially contributing to bone health issues in broilers.