Effect of maternal canthaxanthin and 25-hydroxycholecalciferol supplementation on the performance of ducklings under two different vitamin regimens

Use of 25-hydroxyvitamin D3 in diets for sows: A review

Dietary supplementation with 25-hydroxyvitamin D₃ (25OHD₃), as an alternative source of vitamin D, is becoming increasingly popular due to its commercialization and more efficient absorbability. The addition of 25OHD₃ rather than its precursor vitamin D₃ can circumvent the 25-hydroxylation reaction in the liver, indicating that supplementation of 25OHD₃ can rapidly improve the circulating vitamin D status of animals. Emerging experiments have reported that maternal 25OHD₃ supplementation could increase sow performances and birth outcomes and promote circulating vitamin D status of sows and their offspring. Increased milk fat content was observed in many experiments; however, others demonstrated that adding 25OHD₃ to lactating sow diets increased the contents of milk protein and lactose. Although an inconsistency between the results of different experiments exists, these studies suggested that maternal 25OHD₃ supplementation could alter milk composition via its effects on the mammary gland. Previous studies have demonstrated that adding 25OHD₃ to sow diets could improve the mRNA expressions of insulin-induced gene 1 (INSIG1) and sterol regulatory element-binding protein 1 (SREBP1) in the mammary gland cells from milk and increase the mRNA expressions of acetyl-CoA carboxylase α (ACCα) and fatty acid synthase (FAS) in the mammary gland tissue. Maternal 25OHD₃ supplementation promotes skeletal muscle development of piglets before and after parturition, and improves bone properties including bone density and bone breaking force in lactating sows and their piglets. Interestingly, 25OHD₃ supplementation in sow diets could improve neonatal bone development via regulation of milk fatty acid composition related to bone metabolism and mineralization. In this review, we also discuss the effects of adding 25OHD₃ to sow diets on the gut bacterial metabolites of suckling piglets, and propose that butyrate production may be associated with bone health. Therefore, to better understand the nutritional functions of maternal 25OHD₃ supplementation, this paper reviews advances in the studies of 25OHD₃ for sow nutrition and provides references for practical application.

Dietary supplementation of 25-hydroxycholecalciferol increases tibial mass by suppression bone resorption in meat ducks

Leg problems often result from the rapid weight gain and poor bone quality in modern ducks, leading to a high risk of fractures and continuous pain. We hypothesized that improving bone quality in combination with delaying weight gain via a low nutrient density (LND) diet probably reverses these skeletal abnormalities. Studies indicated that 25-hydroxycholecalciferol (25-OH-D₃), a vitamin D₃ metabolite, is effective in treating bone-related disorders. Therefore, Exp. 1 evaluated the effects of 25-OH-D₃ on tibial mass of meat ducks. Male meat ducklings were fed a standard nutrient density diet (containing a regular vitamin regimen) without or with 25-OH-D₃ at 0.069 mg/kg for 35 d. The results showed that 25-OH-D₃ supplementation improved the mineral content, microarchitecture and mechanical properties of tibias, and this companied by a decreased serum bone resorption marker and a concomitant decrement in osteoclast-specific marker genes expression. Subsequently, Exp. 2 was conducted to examine the impacts of 25-OH-D₃ incorporating an LND diet on tibial quality of ducks under 2 different vitamin regimens (regular and high). Ducklings were allocated to a 2 × 2 factorial arrangement with 2 kinds of vitamin premixes and without or with 25-OH-D₃ at 0.069 mg/kg in LND diets. The high premix had higher levels of all vitamins except biotin than the regular premix. The results demonstrated that high vitamin diets exhibited more significant effects than regular vitamin diets on inhibiting bone turnover and increasing minerals deposition. Tibial mineral content, microarchitecture, and strength of birds under the regular vitamin regimen were increased by 25-OH-D₃ supplementation; However, these positive effects were not observed in ducks under the high vitamin regimen. To conclude, 25-OH-D₃ supplementation improves tibial mass by suppressing osteoclast-mediated bone resorption in meat ducks, and this positive impact only was observed in regular but not high vitamin regimen when birds fed an LND diet.

Effects of 25-hydroxycholecalciferol supplementation in maternal diets on reproductive performance and the expression of genes that regulate lactation in sows

One hundred Yorkshire × Landrace sows were randomly assigned to one of two dietary treatments (diet ND: 6,000 IU vitamin D₃ /d feed; diet 25-D: 200 μg/day 25OHD₃ feed). The experiment began on d 90 of gestation and continued until weaning on day 21 of lactation. In sows that received 25OHD₃ , the growth rate of the piglets before weaning was significantly accelerated (0.266 kg/day, p < .05). Sow serum was collected after weaning, and those in the 25OHD₃ group were found to have significantly higher serum calcium (CA) and phosphorus (PI) levels (p < .05). Interestingly, the oestrus cycle of sows fed 25OHD₃ was significantly shortened (p < .05), the oestrus time was concentrated on the fifth day after weaning, and the piglets were born with a higher degree of uniformity (p < .05). Colostrum was collected on the day of delivery, and the colostrum of sows fed 25OHD₃ contained higher milk fat content than the control group (p < .05). 25OHD₃ supplementation increased the mRNA and protein expression of INSIG1 and SREBP1, which regulate milk fat synthesis, in the mammary gland of lactating sows (p < .05). In conclusion, 25OHD₃ supplementation in maternal diets improved reproductive performance, milk fat content and the mRNA and protein levels of genes regulating milk fat synthesis in lactating sows.

Mineral requirements in ducks: an update

Mineral nutrition plays a critical role in growth and bone mineralization in meat ducks as well as reproductive performance in duck layers and duck breeders. In addition to improving production performance parameters, minerals are also essential to support several enzymatic systems to enhancing antioxidant ability and immune function. This review explores the biological function and metabolism of minerals in the body, as well as mineral feeding strategy of various species of ducks. Topics range from mineral requirement to the physiological role of macroelements such as calcium and phosphorus and microelements such as zinc and selenium, etc. As with the improvement of genetic evolution and upgrade of rearing system in duck production, mineral requirements and electrolyte balance are urgent to be re-evaluated using sensitive biomarkers for the modern duck breed characterized by the rapid growth rate and inadequate bone development and mineralization. For duck breeders, mineral nutrition is not only required for maximal egg production performance but also for maintaining normal embryonic development and offspring's performance. Therefore, the proper amounts of bioavailable minerals need to be supplemented to maintain the mineral nutritional state of duck species during all phases of life. In addition, more positive effects of high doses microelements supplementations have been revealed for modern meat ducks subjected to various stresses in commercial production. The nutritional factors of mineral sources, supplemental enzymes, and antinutritional factors from unconventional ingredients should be emphasized to improve the effectiveness of mineral nutrition in duck feed formulation. Organic mineral sources and phytase enzymes have been adopted to reduce the antagonistic action between mineral and antinutritional factors. Therefore, special and accurate database of mineral requirements should be established for special genotypes of ducks under different rearing conditions, including rearing factors, environmental stresses and diets supplemented with organic sources, phytase and VD₃.

Effect of dietary 25-hydroxycholecalciferol on the sternal mass of meat ducks under different vitamin regimens

Genetic selection and intensive nutrition for increased growth rate in meat-type ducks has resulted in an imbalance between pectorales increment and sternal mass, which is detrimental to productivity and welfare. Reducing body weight and increasing sternal mass probably reverses these adverse effects. Therefore, 2 experiments (Expt.) were conducted to investigate the effects of 25-hydroxycholecalciferol (25-OH-D3), a vitamin D3 metabolites, on sternal mass. In Expt. 1, 512 1-day-old male ducks were randomly assigned to 4 low-nutrient density diets and received following treatments in a 2 × 2 factorial arrangement: (i) NRC or China Agricultural industry standards (NY/T) vitamin premixes and (ii) 0.069 mg/kg 25-HyD in feed or not. At 49 D of age, regardless of 25-OH-D3, NY/T vitamin regimen inhibited bone turnover and consequently increased sternal trabecular bone volume and mineral deposition compared with NRC vitamin premix. Supplementing 25-OH-D3 to NRC but not NY/T vitamin regimen significantly improved sternal microarchitecture and mineral content, which companied by decreased serum bone resorption markers concentration, as well as downregulation of the gene expressions of osteoclast differentiation and activity. In Expt. 2, 256 1-day-old male ducks were fed a standard nutrient density diet contained NRC vitamin premix with 0 or 0.069 mg/kg of 25-OH-D3. Results also showed that 25-OH-D3 treatment significantly improved sternal mineral accumulation and microarchitecture, along with decreasing osteoblast and osteoclast numbers in bone surface, declining serum bone turnover markers levels, and increasing serum Ca concentration. Collectively, these findings indicated that the dietary administration of 25-OH-D3 increased sternal mass in NRC vitamin diet by suppressing bone resorption in 49-day-old meat duck.