Effects of 25-hydroxy-cholecalciferol on the development of osteochondrosis in swine

Bioconversion of vitamin D3 to bioactive calcifediol and calcitriol as high-value compounds

Biological catalysis is an important approach for the production of high-value-added compounds, especially for products with complex structures. Limited by the complex steps of chemical synthesis and low yields, the bioconversion of vitamin D₃ (VD₃) to calcifediol and calcitriol, which are natural steroid products with high added value and significantly higher biological activity compared to VD₃, is probably the most promising strategy for calcifediol and calcitriol production, and can be used as an alternative method for chemical synthesis. The conversion efficiency of VD₃ to calcifediol and calcitriol has continued to rise in the past few decades with the help of several different VD₃ hydroxylases, mostly cytochrome P450s (CYPs), and newly isolated strains. The production of calcifediol and calcitriol can be systematically increased in different ways. Specific CYPs and steroid C25 dehydrogenase (S25DH), as VD₃ hydroxylases, are capable of converting VD₃ to calcifediol and calcitriol. Some isolated actinomycetes have also been exploited for fermentative production of calcifediol and calcitriol, although the VD₃ hydroxylases of these strains have not been elucidated. With the rapid development of synthetic biology and enzyme engineering, quite a lot of advances in bioproduction of calcifediol and calcitriol has been achieved in recent years. Therefore, here we review the successful strategies of promoting VD₃ hydroxylation and provide some perspective on how to further improve the bioconversion of VD₃ to calcifediol and calcitriol.

Efficacy and safety of a novel source of dietary 25-hydroxycholecalciferol in growing pigs

A randomized complete block design experiment was conducted to determine the safety and efficacy of supplementation of increasing concentrations of a novel, bacterial fermentation-derived vitamin D source on growth performance and tissue deposition of 25-hydroxycholecalciferol (25OHD3) in growing swine. Dietary treatments were as follows: commercial control with vitamin D3 (CON) at NRC recommended concentrations and three diets composed of CON + increasing inclusions (25, 50, and 250 µg/kg equivalent) of 25OHD3 from a novel source (CON + 25; CON + 50; and CON + 250, respectively). Pigs (n = 144) were assigned to 24 pens which were allotted to one of the four dietary treatments and fed for 42 d. Blood samples were collected for 25OHD3 concentration determination and individual body weights (BW) were measured on experimental day 0, 39, and 63. On day 42, tissues from 48 pigs (12 pigs per dietary treatment) were analyzed for 25OHD3 concentration. No differences were observed in growth performance. Day 39 serum 25OHD3 concentrations were greatest in CON + 250-fed pigs and linearly decreased as dietary 25OHD3 inclusion decreased (P < 0.0001). On day 42, tissue 25OHD3 concentrations increased linearly as 25OHD3 increased in the diet (P < 0.0001). On day 63, 21 d after dietary 25OHD3 withdrawal, serum 25OHD3 concentrations of all 25OHD3-fed pigs decreased to that of or within 2.76 ± 0.89 ng/mL of CON-fed pigs which demonstrates that feeding 250 µg/kg 25OHD3 is well tolerated by growing pigs and will clear the body within 21 d.

Dietary supplementation of 25-hydroxycholecalciferol as an alternative to cholecalciferol in swine diets: A review

25-hydroxycholecalciferol (25-OHD₃ ) formed via hepatic hydroxylation from vitamin D, cholecalciferol, represents the precursor of the biologically active vitamin D hormone, 1,25-dihydroxyvitamin D. Due to a higher absorption rate and the omission of one hydroxylation, dietary supplementation of 25-OHD₃ instead of vitamin D₃ is considered to be more efficient as plasma concentrations of 25-OHD₃ are increased more pronounced. The present review summarises studies investigating potential beneficial effects on mineral homeostasis, bone metabolism, health status and performance in sows, piglets and fattening pigs. Results are inconsistent. While most studies could not demonstrate any or only a slight impact of partial or total replacement of vitamin D₃ by 25-OHD₃ , some experiments indicated that 25-OHD₃ might alter physiological processes when animals are challenged, for example, by a restricted mineral supply.

Gilt development to improve offspring performance and survivability

Methods for developing incoming replacement gilts can indirectly and directly influence survivability of their offspring. Indirectly, having proper gilt development reduces culling rates and mortality, which increases longevity and creates a more mature sow herd. Older sows are more likely to have greater immunity than gilts and therefore can pass this along to their pigs in both quantity and quality of colostrum and milk, thus improving piglet survivability. Directly, proper gilt development will maximize mammary gland development which increases colostrum and milk production leading to large, healthy pig. As for the developing gilt at birth, increasing colostrum intake, reducing nursing pressure, providing adequate space allowance, and good growth rate can increase the likelihood that gilts successfully enter and remain in the herd. Light birth weight gilts (<1 kg) or gilts from litters with low birth weight should be removed early in the selection process. Gilts should be weaned at 24 d of age or older and then can be grown in a variety of ways as long as lifetime growth rate is over 600 g/d. Current genetic lines with exceptional growth rate run the risk of being bred too heavy, reducing longevity. On the other hand, restricting feed intake at specific times could be detrimental to mammary development. In these situations, reducing diet amino acid concentration and allowing ad libitum feed is a possible strategy. Gilts should be bred between 135 and 160 kg and at second estrus or later while in a positive metabolic state to increase lifetime productivity and longevity in the herd. Once bred, gilts should be fed to maintain or build body reserves without becoming over-conditioned at farrowing. Proper body condition at farrowing impacts the percentage of pigs born alive as well as colostrum and milk production, and consequently, offspring performance and survivability. Combined with the benefit in pig immunity conferred by an older sow parity structure, gilt development has lasting impacts on offspring performance and survivability.

Recent advances of vitamin D in immune, reproduction, performance for pig: a review

Vitamin D (VD) has been reported to play multiple and significant roles in improving pig health via modulating calcium and phosphorus homeostasis, skeletal muscle development and the immune system. Apart from food, photochemical action of 7-dehydrocholesterol in the skin is the main source of this molecule for pigs. The VD from dietary intake or photosynthesized via skin can be absorbed into the liver for hydroxylation, and further hydroxylated into the hormone form of VD (1,25-dihydroxyvitamin D3 or 1,25(OH)2D3) in the kidney. As a sterol hormone, 1,25(OH)2D3 is able to bind with the VD receptor (VDR), and this ligand-receptor complex (VDR/retinoic X receptor) translocates from the cytoplasm into the nucleus to regulate gene expression, thus modulating metabolism. In this review, we summarized the recent studies regarding the non-skeletal health benefits of VD for pigs, and focused on the recent advances in the cellular and molecular mechanisms of VD that affects the immune system and reproductive health. This review provides a reference for future research and application of VD in pigs.

Skeletal health, redox balance and gastrointestinal functionality in dairy cows: connecting bugs and bones

This research reflection examines the physiological links between redox balance, skeletal health and gastrointestinal functionality in dairy cows. With the increase in demand of animal products caused by the growth in human population, the dairy industry needs to develop and implement innovative strategies which are profitable, sustainable and cow friendly. Redox balance, skeletal heath and gastrointestinal functionality are three key physiological systems that are often seen as independent entities. In this research reflection we intend to stress that the antioxidant system, bone health and the microbiome are intimately intertwined. Antioxidants are crucial for the maintenance of redox homeostasis and optimal immune function. Optimal gastrointestinal functionality is important to maintain animal performance, health and welfare. In particular, the intestinal microbiome is increasingly seen as a driver of health and disease. Vitamin D metabolism is pivotal not only for optimal skeletal health, but in light of all the extra-skeletal effect of vitamin D, it is the foundation for optimal productive life. It makes sense to ask the question 'how are redox balance and the microbiome involved in the modulation of bone health and immune function?' In other words, are bugs and bones connected in dairy cows! The existing data available in the literature suggests that this might be the case. The characterization of the interactions between redox balance, skeletal health and the microbiome, will allow the development of a multisystem biological approach to refine nutritional interventions to improve dairy cattle health, welfare and productive longevity.

Alleged predisposing dietary factors fail to increase the incidence of osteochondrosis-like lesions in growing pigs at 14 and 24 wk of age

Early lesions of osteochondrosis (OC) are exhibited by regions of cartilage retention along the growth plate and articular cartilage. Progression of OC lesions may impair locomotion and necessitate euthanasia in adherence to animal welfare guides. Little is known about the role of nutrition in the initiation and early stages of OC. However, dietary components are commonly implicated as predisposing factors. In this study, diets were altered as an attempt to induce early stage OC lesions under controlled conditions. At 8 wk of age, 96 crossbred gilts (body weight [BW] = 17.4 ± 0.18 kg) were randomly assigned to one of four corn-soybean meal-based diets (four pens per diet, six pigs per pen) to assess diet effects on the number and volume of OC lesions in the distal femur. Diets included a non-pelleted control diet (Ctl); Ctl plus 20% glucose (Glc); the Ctl with increased concentrations of lysine, Ca, and P (+CaP); and the +CaP diet in a pelleted form (PEL). Femurs were collected from pigs euthanized at either 14-wk (Wk 14) or 24-wk (Wk 14) of age for assessments of OC lesions. Based on a mixed model analysis with pen as the experimental unit, dietary treatments did not affect final BW (129.3 ± 3.8 kg) or average daily gain (ADG) (1.00 ± 0.03 kg/d) over the trial. As expected, pigs fed PEL and Glc diets were more efficient (P < 0.05) in feed conversion compared with Ctl and +CaP. Using femurs as the experimental unit at Wk 14 (collected from two of the six pigs per pen), bone mineral content, determined by dual-energy x-ray absorptiometry scans, was greater (P < 0.05) in pigs fed +CaP and PEL than Ctl or Glc diets; however, only +CaP group differed (P < 0.05) at Wk 24 (collected from four pigs per pen). Computed tomography (CT) scans of femurs were reconstructed as three-dimensional images to allow detection of the number, volume, and surface area of lesions in distal growth plates. At Wk 14, pigs fed Ctl had fewer number of lesions (P < 0.05); however, no differences were detected among dietary treatments in lesion volume or lesion surface area. Pigs had fewer lesions at Wk 24 than Wk 14; however, differences were not detected among dietary treatments. At Wk 24, pigs fed Ctl diets had the greatest lesion volume among dietary treatments (P < 0.05). In conclusion, none of the pigs exhibited symptoms of lameness regardless of dietary treatment or OC lesion traits. Diet modifications due to pelleting or inclusion of rapidly digestible ingredients, such as glucose, did not increase prevalence or size of OC lesions. Image analysis of CT scans was a reliable method to quantify the number, size, and location of OC lesions.

High Levels of Circulating Type II Collagen Degradation Marker (CTx-II) Are Associated with Specific VDR Polymorphisms in Patients with Adult Vertebral Osteochondrosis

Both vitamin D and collagen have roles in osteocartilaginous homeostasis. We evaluated the association between the circulating 25-hydroxyvitamin D (25(OH)D) type I and II collagen degradation products (CTx-I, and CTx-II), and four vitamin D receptor gene (VDR) polymorphisms, in Italian males affected by low back pain (LBP) due to herniation/discopathy and/or vertebral osteochondrosis. FokI, BsmI, ApaI, and TaqI VDR-polymorphisms were detected through PCR-restriction fragment length polymorphism (RFLP), and circulating 25(OH)D, CTx-I and CTx-II were measured by immunoassays in 79 patients (of which 26 had osteochondrosis) and 79 age-, sex- and body mass index (BMI)-matched healthy controls. Among all 158 subjects, carriers of FF and Ff genotypes showed lower 25(OH)D than ff, which suggested a higher depletion of vitamin D in F allele carriers. Higher CTx-I concentrations were observed in TT versus Tt among controls, and Tt versus tt among LBP cases, which suggested a higher bone-cartilaginous catabolism in subjects bearing the T allele. Higher CTx-II concentrations were observed in patients with osteochondrosis bearing FF, bb, TT, or Aa genotypes in comparison with hernia/discopathy patients and healthy controls. Vertebral osteochondrosis shows peculiar genotypic and biochemical features related to vitamin D and the osteocartilaginous metabolism. Vitamin D has roles in the pathophysiology of osteochondrosis.

Nutritional strategies in ruminants: A lifetime approach

This review examines the role of nutritional strategies to improve lifetime performance in ruminants. Strategies to increase ruminants' productive longevity by means of nutritional interventions provide the opportunity not only to increase their lifetime performances and their welfare, but also to decrease their environmental impact. This paper will also address how such nutritional interventions can increase herd efficiency and farm profitability. The key competencies reviewed in this article are redox balance, skeletal development and health, nutrient utilization and sustainability, which includes rearing ruminants without antibiotics and methane mitigation. While the relationships between these areas are extremely complex, a multidisciplinary approach is needed to develop nutritional strategies that would allow ruminants to become more resilient to the environmental and physiological challenges that they will have to endure during their productive career. As the demand of ruminant products from the rapidly growing human world population is ever-increasing, the aim of this review is to present animal and veterinary scientists as well as nutritionists a multidisciplinary approach towards a sustainable ruminant production, while improving their nutrient utilization, health and welfare, and mitigation of their carbon footprint at the same time.

Nutritional management of group-housed gestating sows – key challenges in the transition from stall-housing systems

Transition from gestation stalls to group-housing systems is a source of trepidation for many pork producers, given the capital cost of conversion and the challenges associated with managing sows in groups. Despite this, market imperatives in Australia have led to rapid transition in many enterprises. The cost of conversion of a 4100-sow unit from stalls to groups using low-cost retrofitting of existing breeder space (AU$150.00/sow) at relatively high densities (1.8 m2/sow) in small static groups (15–20 sows) based on floor or trough feeding with or without head bales and shoulder partitions equates to an additional cost of $3.00/piglet weaned if the level of productivity is maintained. If the number of piglets born per litter is increased by 1.04 piglets per litter, overall earnings of the herd are equal to levels achieved before the transition. This capital cost appears manageable if appropriate nutritional regimens are implemented to address individual nutritional needs of sows housed in groups and to manage aggression. Management of sow body condition during the reproductive cycle focussed on standardised gilt introduction to the breeding herd and optimisation of sow and gilt feed intake in lactation is pivotal, as it reduces the need for remedial feeding of individual sows post-weaning and during gestation. Nutritional management can also be used to reduce aggression between sows by removing impediments to feed access and by induction of satiety. Commercial implementation of these strategies confirms their relevance and demonstrates that sows can be cost-effectively managed in group-housing systems.