Effects of dietary calcium and phosphorus levels and supplementation of 25-hydroxycholecalciferol on performance and bone properties of broiler starters

Dietary 25-Hydroxycholecalciferol Supplementation from Day 85 of Gestation to Farrowing Enhances Performance, Antioxidant Capacity, and Immunoglobulins of Sows and Newborn Piglets

In this study, the aim was to evaluate the effects of dietary 25-hydroxycholecalciferol supplementation from day 85 of gestation on performance, antioxidant capacity, and immunoglobulin level of sows and newborn piglets. On day 85 of gestation, forty Landrace × Yorkshire gestating sows (average body weight of 241 ± 6.8 kg; average parity of 3.47 ± 0.6) were allotted into two treatments (20 replicates per treatment) based on parity, body weight, and back fat thickness. From day 85 of gestation to farrowing, sows were fed a normal vitamin D3 diet as control (containing 50 μg/kg vitamin D3; CON), or a 25-hydroxycholecalciferol-supplemented diet (containing 50 μg/kg 25-hydroxycholecalciferol). Compared with CON, dietary 25-hydroxycholecalciferol supplementation increased (p < 0.05) protein and fat content in colostrum and the average birth body weight of newborn piglets. Sows fed 25-hydroxycholecalciferol showed increased (p < 0.05) apparent total tract digestibility of crude protein compared with CON. Diets supplemented with 25-hydroxycholecalciferol also increased (p < 0.05) the content of superoxide dismutase (SOD), and tended to increase (p = 0.06) the total antioxidant capacity content and reduce (p = 0.09) the malondialdehyde (MDA) level in colostrum. An increase (p < 0.05) in the content of SOD and a reduction (p < 0.05) in the content of MDA in the serum of newborn piglets was also observed in the 25-hydroxycholecalciferol treatment compared with CON. Dietary 25-hydroxycholecalciferol supplementation also enhanced (p < 0.05) the immunoglobulin G content and reduced (p < 0.05) the concentration of tumor nuclear factor-α in the serum of sows, as well as reducing (p < 0.05) the content of immunoglobulin G and immunoglobulin A in the serum of newborn piglets compared with CON. Supplementation of 25-hydroxycholecalciferol in sow diets increased (p < 0.05) the content of alkaline phosphatase in the serum and colostrum of sows, the concentration of insulin and crosslap in serum of sows, and the serum calcium content of newborn piglets compared with CON. In conclusion, dietary 25-hydroxycholecalciferol supplementation from day 85 of gestation could enhance performance, antioxidant capacity, and immunoglobulin in sows and newborn piglets.

Heavy metal contamination in eggs on poultry farms and ecological risk assessment around a gold mine area in northern Thailand

The aim of this study was to analyze and compare the Hg, Pb, Cd, and Mn levels in egg feed, soil, and water among laying hens, laying ducks, and free-grazing duck farms in contaminated and uncontaminated areas. This study revealed that the Hg concentration in the eggs of free-grazing ducks was significantly greater than that in the eggs of laying hens and ducks in both contaminated and uncontaminated areas. However, the Pb and Mn levels in the eggs of laying ducks and free-grazing ducks were significantly greater than those in the eggs of laying hens in the contaminated area. Unfortunately, the Hg, Pb, Cd, and Mn concentrations in the feed, soil, and water from these three farms in both areas were not significantly different (P > 0.05). Hg and Cd were confirmed to be enriched in the egg albumin fraction, while Pb and Mn were found mainly in the egg yolk. However, egg consumption from free-grazing duck farms was the riskiest to Hg, Pb, and Mn contamination in the contaminated area. Additionally, the ecological risk factor (ER) in the soil revealed that all the farms were at considerable to high environmental risk for Cd except for Hg and Pb. Although the potential ecological risk index (RI) indicated a moderate risk for all farms in both contaminated and uncontaminated areas, these results were not consistent with our hypothesis. Therefore, the information gained in this study could be useful for setting up mitigation strategies and making decisions about public health concerns related to health hazards, especially for ecological risk assessments of heavy metal contamination.

Reduced bone formation and increased bone resorption drive bone loss in Eimeria infected broilers

Coccidiosis is an economically significant disease in the global poultry industry, but little is known about the mechanisms of bone defects caused by coccidiosis; thus, the study focused on effects of coccidiosis on the bone homeostasis of young broiler chickens. A total of 480 male Cobb500 broilers were randomly allocated into four treatment groups, including an uninfected control consuming diet ad libitum, two infected groups were orally gavaged with two different concentrations of sporulated Eimeria oocysts, and an uninfected pair-fed group fed the same amount of feed as the high Eimeria-infected group consumed. Growth performance and feed intake were recorded, and samples were collected on 6 days post infection. Results indicated that coccidiosis increased systemic oxidative status and elevated immune response in bone marrow, suppressing bone growth rate (P < 0.05) and increasing bone resorption (P < 0.05) which led to lower bone mineral density (P < 0.05) and mineral content (P < 0.05) under Eimeria infection. With the same amount of feed intake, the uninfected pair-fed group showed a distinguished bone formation rate and bone resorption level compared with the Eimeria infected groups. In conclusion, inflammatory immune response and oxidative stress in broilers after Eimeria infection were closely associated with altered bone homeostasis, highlighting the role of inflammation and oxidative stress in broiler bone homeostasis during coccidiosis.

Dietary 25-hydroxycholecalciferol supplementation improves performance, immunity, antioxidant status, intestinal morphology, and bone quality in weaned piglets

BACKGROUND

25-Hydroxycholecalciferol (25OHD₃ ) is a new feed additive, which is a potential alternative to vitamin D₃ in swine nutrition. The objective of this study was to determine the effects of different doses of 25OHD₃ supplementation on performance, immunity, antioxidant capacity, intestinal morphology and bone quality in piglets.

RESULTS

As dietary 25OHD₃ supplementation increased, the average daily gain (ADG) improved (P < 0.05) quadratically during days 1-14, and tended to increase (P = 0.06) quadratically during the overall period of the experiment. Increasing 25OHD₃ supplementation increased (linear effect, P < 0.05) the serum 25OHD₃ level and serum glutathione peroxidase (GSH-Px) activity. On day 14, serum immunoglobulin A (IgA) was increased (linear and quadratic effects, P < 0.05) as dietary 25OHD₃ supplementation increased. On day 28, serum IgA level was higher (P < 0.05) linearly and the complement 3 (C3) level was reduced (P < 0.05) linearly as dietary supplementation of 25OHD₃ increased. The mucosal GSH-Px activity of the small intestine was higher (quadratic effect, P < 0.05) with increasing 25OHD₃ supplementation. Jejunal villus height (P = 0.06) and villus height to crypt depth ratio (P = 0.07) tended to increase quadratically, and the villus height to crypt-depth ratio of the ileum increased (P < 0.05) linearly and quadratically with increasing 25OHD₃ supplementation. Dietary supplementation with an increasing level of 25OHD₃ increased breaking strength of tibias and femurs (quadratic effect, P < 0.05).

CONCLUSION

Increasing dietary 25OHD₃ supplementation partly improved performance, immunity, antioxidant status, intestinal morphology, and bone properties of weaned piglets. © 2020 Society of Chemical Industry.

Body weight of young broilers fed with declining calcium and phosphorus contents during the starter period is irresponsive to changes in the skeleton

To evaluate the effect of reduced calcium (Ca) and available P (aP) levels in starter diets on growth performance and tibia, sternum and serum characteristics, and to assay the association between Ca and P (aP) intakes and these variables, 600 one-day-old broiler chicks (Ross 308) were used in a 21-days trial. Broilers were randomly allotted to five treatments with five replicate pens. Chicks were fed on one of the five starter diets that were formulated with a 10% reduction in the Ca and aP contents, starting from the control diet and hence, named as C (0.96% Ca, 0.45% aP), L1 (0.85% Ca and 0.42% aP), L2 (0.77% Ca and 0.38% aP), L3 (0.68% Ca and 0.34% aP) and L4 (0.61% Ca and 0.31% aP). Declining dietary Ca and aP levels did not affect body weight and levels of Ca, P and alkaline phosphatase in serum, but reduced linearly feed intake, the feed conversion ratio and the bone weight and ash content. The Ca and aP intakes and Ca:aP ratio displayed a positive correlation with both tibia and sternum weights, and the mass of the bones were equally sensitive to dietary Ca and aP levels. In conclusion, the body weight of young broilers was irresponsive to changes in the skeleton when exposed to early dietary Ca and aP restrictions (up to 0.61% Ca and 0.31% aP) and the mechanostat had limits due to the association between Ca and aP intakes, and bone properties.