Immunohistochemical study of matrix metalloproteinase‐3 (MMP‐3) at the articular cartilage in osteochondrotic pigs

In order to understand the mechanism of osteochondrosis in the pig, articular cartilage was taken from the distal femoral condyles of Duroc pigs exhibiting leg weakness and then examined immunohistochemically for the localization of matrix metalloproteinases‐3 (MMP‐3), one of the enzymes involved in the resolution of cartilage matrix. The articular cartilage had the typical characteristics of osteochondrotic lesions, such as abnormal calcification, clefts of cartilage, disappearance of proteoglycan, and necrotic chondrocytes. The immunoreaction of MMP‐3 was observed in chondrocytes at the boundary between normal cartilage and proteoglycan‐deficient area. Moreover, chondrocytes expressing MMP‐3 showed normal morphology, but the surrounding cartilage matrix did not stain with toluidine blue, which indicated a lack of glycosaminoglycans. These results suggest that MMP‐3 is highly involved in the appearance and expansion of osteochondrotic lesions.     

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

This study investigated the effects of maternal canthaxanthin (CX, 6 mg/kg) and 25‐hydroxycholecalciferol (25‐OH‐D₃, 0.069 mg/kg) supplementation on the performance of Cherry Valley ducklings under two different vitamin regimens. A total of 780 duck breeder females and 156 males were randomly allotted to two diets with or without the addition of the mixture of CX and 25‐OH‐D₃ (CX+25‐OH‐D₃) for 32 weeks. Ducklings (males and females separately) hatched from eggs laid at 24 weeks of the duck breeder trial were fed with a NRC vitamin regimen, and ducklings (males and females separately) hatched from eggs laid at 32 weeks of the duck breeder trial were fed with a HIGH vitamin regimen (had higher levels of all vitamins except biotin than NRC vitamin regimen), for 14 days. The results showed that, maternal CX+25‐OH‐D₃ supplementation increased the shank pigmentation for 7‐days post hatch in ducklings under a NRC vitamin regimen, and for 14‐days post hatch in ducklings under a HIGH vitamin regimen. Growth performance, antioxidant status and serum phosphorus of ducklings under a NRC vitamin regimen were increased by maternal CX+25‐OH‐D₃ supplementation; however, these positive effects were not observed in ducklings under a HIGH vitamin regimen. Males revealed increased growth performance in ducklings under both NRC and HIGH vitamin regimens. Sexual differences in shank pigmentation, antioxidant status, tibia strength and serum phosphorus were not consistent as they were dependent on maternal CX+25‐OH‐D₃ status or dietary vitamin regimens. Data suggest that maternal CX+25‐OH‐D₃ supplementation is important for starter ducklings under a NRC vitamin regimen, but not HIGH vitamin regimen.     

The effect of 25‐hydroxyvitamin D3 and phytase inclusion on pig performance,bone parameters and pork quality in finisher pigs

The objective of this study was to investigate the effects of supplementing both phytase and 25‐hydroxyvitamin D₃ (25‐OH ‐D?) on pig performance, nutrient digestibility, carcass characteristics, bone parameters and pork quality in finisher pigs. The experimental design was a 2 × 2 factorial comprising of four dietary treatments. One hundred and twenty pigs (60 male, 60 female) were blocked according to live weight and sex and allocated to the following dietary treatments: low P (4.81 g/kg) diet (basal) (T1); low P diet + phytase (T2); low P diet + 25‐OH ‐D? (T3) and low P diet + phytase + 25‐OH ‐D? (T4). Pigs supplemented with phytase had a lower average daily feed intake (ADFI ) (2.45 kg vs. 2.59 kg; p  < 0.05) and lower feed conversion ratio (FCR ) (2.74 kg/kg vs. 2.85 kg/kg; p  <  0.05) compared to pigs offered the nonphytase diets. Pigs offered phytase diets had a higher (p  <  0.05) coefficient of apparent total tract digestibility (CATTD ) of ash, phosphorous (P) and calcium (Ca) compared with pigs offered the nonphytase supplemented diets. Pigs offered the 25‐OH ‐D₃ diets had a higher CATTD of N and ash. Pigs offered the phytase diets had increased (p  <  0.05) bone DM , ash, Ca, P and density compared to the nonphytase diets. There was a significant interaction (p  <  0.05) between phytase and 25‐OH ‐D₃ on cook loss. Pigs offered 25‐OH ‐D₃ had increased cook loss over the basal diet; however, there was no effect on cook loss when phytase and 25‐OH ‐D₃ were offered in combination compared to the phytase only diet. Pigs offered 25‐OH ‐D₃ exhibited higher (p  <  0.05) Warner Bratzler shear force values and lower (p  <  0.05) pork lightness (L *) surface colorimeter values. In conclusion, there was no benefit to offering a combination of phytase and 25‐OH ‐D₃ on pig performance, bone parameters or pork quality.     

The effect of dietary vitamin D supplementation on sodium-dependent phosphate uptake and expression of NaPi-IIb in the small intestine of weanling pigs

Two experiments were conducted to investigate the effects of 1,25(OH)₂D₃ to stimulate Na⁺-dependent phosphate uptake in Caco-2 cells, and the effects of dietary vitamin D supplementation to vitamin D-deficient nursery pigs on Na⁺-dependent nutrient uptake and mRNA expression of NaPi-IIb cotransporter and calbindin D9k in the jejunum. In Exp. 1, 250,000 Caco-2 cells were seeded on Costar 12 mm Snapwell inserts with a 0.40 µm polycarbonate filter and a seeding density of 0.25 × 10⁶ and studied at 15 d postconfluence. Cells were treated with 10 nM of either 1,25(OH)₂D₃ or vehicle for 48 h and then mounted in modified Ussing chambers for transepithelial measurements. In Exp. 2, pigs (n = 32) were removed from sows at 3 d of age, placed on a vitamin D-deficient milk replacer diet and housed in a room devoid of sunlight and UV light in the range of 280 to 300 nm. On day 28, serum 25(OH)D₃ concentrations were measured to verify low vitamin D status. Pigs (BW 10.10 ± 0.38 kg) were then individually housed day 28 postweaning and allotted to 1 of 2 dietary treatments. Dietary treatments consisted of corn-soybean-based diets with vitamin D supplementations of 0 or 1,500 IU/kg diet for 12 d. Blood samples were taken from the brachiocephalic vein on the initial (day 0) and final day (day 10, 11, or 12) of the study for analysis of serum 25(OH)D₃, P, and Ca. Pigs were euthanized and jejunal segments were harvested and used in modified Ussing chambers and for RNA isolation and subsequent quantitative RT-PCR analysis. In Exp. 1, treating Caco-2 cells with 10 nM 1,25(OH)₂D₃ resulted in a 52% increase (P < 0.005) in Na⁺-dependent phosphate uptake compared with cells treated with a vehicle. In Exp. 2, Na⁺-dependent phosphate and glucose transport did not differ (P > 0.10) among treatment groups. Additionally, NaPi-IIb and calbindin D9k mRNA expression were not different (P > 0.10) between treatment groups. No differences (P > 0.10) were detected in final serum P or 25(OH)D₃ concentrations between treatments. However, serum Ca linearly increased (P < 0.05) as the concentration of supplemental vitamin D increased in the diet. Overall, while 1,25(OH)₂D₃ stimulated Na⁺-dependent phosphate uptake in Caco-2 cells, supplementing diets with 1,500 IU/kg vitamin D₃ from cholecalciferol did not increase jejunal Na⁺-dependent phosphate uptake or NaPi-IIb mRNA expression over that of pigs fed diets with no supplemental cholecalciferol.     

Effects of 25‐hydroxycholecalciferol with two D3 vitamin levels on production and immunity parameters in broiler chickens

This study was performed in Ross 308 chickens aged 1–21 days and aimed to evaluate whether the addition of 25‐hydroxycholecalciferol (25(OH)D₃) to broiler chicken diets affects their growth performance and immunity. A completely random 2 × 2 factorial arrangement was used with two levels of vitamin D₃ and the absence or presence of 25(OH)D₃, corresponding to four treatments based on sorghum + soya bean diets: (i) 200 IU of vitamin D₃/kg of feed (Diet 1) (NRC, 1994 ), (ii) Diet 1 + 69 μg of 25(OH)D₃/kg of feed (Diet 2), (iii) 5,000 IU of vitamin D₃/kg of feed (Diet 3) and (iv) Diet 3 + 69 μg of 25(OH)D₃/kg of feed (Diet 4). Each treatment was conducted with six replicates of 10 chickens each. Water and feed was supplied ad libitum. The results showed significantly increased growth and tibia ash (p < .05) in the birds fed 5,000, IU of vitamin D₃/kg + 25(OH)D₃. Additionally, the cellular immune response increased significantly (p < .05) in both treatments with added 25(OH)D_3. Based on the results obtained under the current test conditions, the addition of 25(OH)D₃ at a rate of 69 μg/kg to diets containing vitamin D₃ improved the cellular immune response and mineral deposition in the bones of broilers aged 1–21 days. Because these parameters are very important in modern poultry farming, these results indicate that supplementation with 25(OH)D₃ should improve broiler production.     

Tolerance evaluation of overdosed dietary levels of 25‐hydroxyvitamin D3 in growing piglets

Forty‐eight, cross‐bred (GL × LW × P) piglets were used in a 42‐day tolerance trial to assess the effects of feeding diets supplemented with vitamin D or increasing levels of 25‐hydroxyvitamin D₃ (25‐OH‐D₃). Six‐week‐old piglets (24 castrate males, 24 females) were used. Two replicate groups of 6 piglets were randomized by weight and allocated to four dietary treatments. The control group (T1) was supplemented with 50 μg vitamin D₃/kg feed. The experimental groups received 25‐OH‐D₃ at the recommended dose (T2: 50 μg/kg = 1x), at 250 μg/kg (T3: 5x) or at 500 μg/kg (T4: 10x) respectively. Feed intake and daily weight gain were measured weekly, and the animals were examined by a veterinarian daily. After 42 days, body mass, blood, urine, bone and tissue samples were analysed and a pathology examination conducted. Dietary treatments had no significant effect on final body mass or daily weight gain. The 25‐OH‐D₃ plasma concentration in T1 was 17 ± 3 ng/ml (mean ± SD) while the respective values of the experimental groups were significantly increased in T2, T3 and T4. Tissue concentrations of 25‐OH‐D₃ were higher in liver and muscle for T3 and T4 and in skin for T4 than in T1. However, neither gross pathology nor histology, nor blood and urine characteristics, nor bone parameters were affected by dietary treatments. Weight of organs as well as dry matter, ash and calcium content of kidneys remained unaffected by dietary 25‐OH‐D₃ intake. Furthermore, no changes were observed for general indicators of health. The results of this study demonstrated that feeding piglets with 25‐OH‐D₃ at 5 or 10 times the recommended level had no adverse effects on any of the biological parameters measured. It was concluded that 25‐OH‐D₃ can be regarded as a supplement with a very high safety margin when used at the recommended level.     

Effect of dietary contents of cholecalciferol, 1α,25‐dihydroxycholecalciferol and 24,25‐dihydroxycholecalciferol on blood concentrations of 25‐hydroxycholecalciferol, 1α,25‐dihydroxycholecalciferol,total calcium and eggshell quality

1. Withdrawal of cholecalciferol (D₃) supplement from a layers diet drastically reduced blood 25‐hydroxycholecalciferol (25‐OH‐D₃), 1α,25‐dihydroxycholecalciferol (calcitriol) and egg specific gravity (SG) within two weeks, followed by a decrease in blood total calcium (Ca).

2. Doubling the D₃ supplement in the control diet (27.5 μg or 1100 IU/kg) almost linearly increased the circulating concentration of 25‐OH‐D₃ without raising the concentration of calcitriol, Ca, or egg SG.

3. Replacing D₃ by the optimal concentration of calcitriol (5 μg/kg diet) improved egg SG after 21 weeks of treatment without increasing blood calcitriol or total Ca.

4. By itself, 24,25‐dihydroxycholecalciferol [24,25‐(OH)₂D₃] was unable to maintain normal blood levels of calcitriol, Ca or egg SG and, when added together with calcitriol in the diet, tended to elevate blood Ca but suppress the beneficial effect of calcitriol on shell quality, with little or no effect on blood calcitriol.     

Free-range system and supplementation of 25-hydroxicholecalciferol increases the performance and serum vitamin levels in mixed-parity sows

Improvements in sow productivity have raised questions regarding dietary vitamin D recommendations. The present study aimed to evaluate the effects of the housing system with access to sunlight exposure and supplementation of 25-hydroxicholecalciferol on performance and serum levels of 25(OH)D₃ in sows during gestation and lactation. Sows were distributed in an experimental design with two housing systems: gestation crates or gestation free-range system with external area for sunlight exposure; and two diets: 0 or 50 μg of 25-hydroxicholecalciferol kg⁻¹. The use of 25-hydroxicholecalciferol tended (P = 0.052) to improve total born and influenced (P = 0.046) on number of born alive. Litter weight at birth was also increased (P = 0.01) by 25-hydroxicholecalciferol supplementation; 25-hydroxicholecalciferol supplementation and housing system (free-range with sunlight exposure) tended to increase weaning weight (P = 0.07) and litter daily gain (P = 0.051) during lactation. Exposure to sunlight and 25-hydroxicholecalciferol supplementation increased 25(OH)D₃ serum levels when compared with control treatment during gestation (136.95 vs. 113.92 ng mL⁻¹; P = 0.035) and lactation (120.29 vs. 88.93 ng mL⁻¹; P = 0.026). In conclusion, the association of 25-hydroxicholecalciferol supplementation with exposure to sunlight during gestation improved significantly 25(OH)D₃ serum levels and consequently performance traits in gestation and lactation.     

Effects of 25(OH)D3 supplementation during late gestation on the serum biochemistry and reproductive performance of aged sows and newborn piglets

The purpose of this study was to investigate the effects of diet type (normal or low Ca and P diets) and 25(OH)D₃ supplementation (with or with not 2000 IU/kg 25(OH)D₃) during late gestation on the serum biochemistry and reproductive performance of aged sows and newborn piglets. A total of 40 sows, which are at their 7th parity, were divided into four groups: control group (standard diet), low Ca group, 25(OH)D₃ group and low Ca plus 25(OH)D₃ group respectively (10 in each group). The blood of sows on day 100 and 114 of gestation and newborn piglets was collected for serum biochemical analyses. Results showed that the reproductive performance of sows was not influenced by diet type or 25(OH)D₃ supplementation (p > 0.05). And the addition of 25(OH)D₃ to diet low Ca group caused that the content of serum TG in sows on day 100 of gestation was not different from that of the control group (p > 0.05). The addition of 25(OH)D₃ significantly decreases the content of serum TG in sows on day 114 of gestation (p < 0.05). The addition of 25(OH)D₃ significantly increased the content of serum UREA and CREA in newborn piglets (p < 0.05). Overall, feeding 2000 IU/kg 25(OH)D₃ to aged sows at late gestation had no effects on reproductive performance, but partly contributed to keeping serum TG balance in sows and may indicate increased pressure on kidneys in newborn piglets.     

The effect of parentage on the prevalence, severity and location of lesions of osteochondrosis in swine

The aims of this study were to determine the effects of parentage and gender on the prevalence, severity and location of lesions of osteochondrosis manifesta (OCM) and osteochondrosis dissecans (OCD) in offspring from different Norwegian Landrace boars and to examine the relationships between lesion characteristics and selected growth parameters. Fifteen sires were selected based on their high breeding value for osteochondrosis. Seven locations in the distal humerus and the distal femur from 1680 offspring of these animals were evaluated for severity of OCM and presence of OCD by gross examination of serially sectioned humeri and femora. Osteochondrosis manifesta was most prevalent in the trochlea of humerus, the sagittal ridge of humerus, the medial condyle of femur and the medial sulcus obliquus of femur. The severity of the lesions and the prevalence of OCD were highest in the trochlea and the sagittal ridge of humerus. Castrates had significantly higher OCM scores than sows. There were significant effects of both sire and dam on the OCM scores of the offspring in most locations; however, growth rate and weight at slaughter did not influence the OCM score.     

Effects of dietary calcium content and vitamin D source on skeletal properties in growing turkeys

1. The aim of the study was to investigate the effects of feeding fast growing turkeys with differentiated dietary calcium (Ca) content, and the partial replacement of vitamin D₃ in the feed with 25-hydroxycholecalciferol (25(OH)D₃), on skeletal properties.

2. One-day-old Big-6 male turkeys (n?=?1008) were randomly divided into 4 groups, and two subgroups were created within each group. The groups were differentiated with 4 levels of Ca provision in the feed, namely 85% of the National Research Council (NRC) recommendation (Group Ca₁); 95% as above (Group Ca₂); 105% as above (Group Ca₃); and 115% as above (Group Ca₄). The first subgroup received the recommended dosage of cholecalciferol (vitamin D₃ subgroup) in the feed, while in the second subgroup (Hy-D subgroup), half of the dosage of cholecalciferol was replaced with 25(OH)D₃. At the ages of 4, 8, 12 and 20 weeks, 7 turkeys from each subgroup were randomly selected and killed to obtain the right tibia for densitometric, geometric and mechanical analyses.

3. This study showed advantageous effects of increased calcium supply in the diet on skeletal system properties, that were increased and produced the most desirable traits in turkeys receiving 95%, 105% and 115% of the NRC calcium recommendation. Benefits resulting from administration of 25(OH)D₃ in the diet were also obtained in the skeletal formation of turkeys, and the most advantageous effects were present in the group receiving 105% of recommended dietary Ca.

4. Effects on the metabolic response of the skeleton of turkeys to manipulation of dietary calcium content and vitamin D₃ source were the most evident in the groups between 4 and 12 weeks of life, and demonstrated a limited ability to induce a positive influence on bone properties at advanced stages of the production cycle by alteration of these dietary factors.     

A comparison of UVb compact lamps in enabling cutaneous vitamin D synthesis in growing bearded dragons

The effect of exposure to different UVb compact lamps on the vitamin D status of growing bearded dragons (Pogona vitticeps) was studied. Forty‐two newly hatched bearded dragons (<24 h old) were allocated to six treatment groups (n = 7 per group). Five groups were exposed to different UVb compact lamps for two hours per day, with a control group not exposed to UVb radiation. At 120 days of age, blood samples were obtained and concentrations of 25(OH)D₃, Ca, P and uric acid were determined. In addition, plasma 25(OH)D₃ concentration was determined in free‐living adult bearded dragons to provide a reference level. Only one treatment resulted in elevated levels of 25(OH)D₃ compared to the control group (41.0 ± 12.85 vs. 2.0 ± 0.0 nmol/L). All UVb‐exposed groups had low 25(OH)D₃ plasma levels compared to earlier studies on captive bearded dragons as well as in comparison with the free‐living adult bearded dragons (409 ± 56 nmol/L). Spectral analysis indicated that all treatment lamps emitted UVb wavelengths effective for some cutaneous vitamin D synthesis. None of these lamps, under this regime, appeared to have provided a sufficient UVb dose to enable synthesis of plasma 25(OH)D₃ levels similar to those of free‐living bearded dragons in their native habitat.     

Pathological changes in the lumbar spine of boars.

Lumbar vertebral columns from 73 boars were examined for pathological changes. While pathological changes were minimal at five months of age, several animals aged seven to 18 months of age had facet asymmetry and large osteophytes surrounding lumbar facets. In the adult group 36% had degeneration of intervertebral discs and 28% had ventrolateral vertebral osteophytes. Lesions characterized by irregular areas of cavitation in the annulus and adjacent vertebral epiphyses were also observed. Of animals submitted for necropsy with a history of clinical lameness. lesions included nonsuppurative polyarthritis, fracture of the sacrum and femoral head, osteochondrosis involving articular cartilage of the distal humerus and distal femur, vertebral osteomyelitis, meningeal abscess and ulnar osteomyelitis.     

UV‐light and dietary vitamin D and their effects on ionized calcium and 25‐OH‐D plasma concentrations in captive gentoo penguins (Pygoscelis papua)

In this study, the effect of ultraviolet (UV) light and dietary vitamin D on calcium metabolism in permanently indoor‐housed gentoo penguins (Pygoscelis papua ) was investigated. The study consisted of three periods, each completed with blood samples to analyse plasma concentrations of 25‐OH‐D, 1,25‐(OH)₂‐D, ionized (iCa) and total calcium (tCa). During the first study period (D), animals were housed under routine conditions without UV‐light and fed a diet of different fish species, supplemented with 1,000 IU vitamin D per animal and day. The following study period (Baseline) of 28‐day duration consisted of the same diet without any vitamin D supplementation and without UV‐light. During the study period (UVB) artificial UV‐light was added for 3 weeks. The vitamin D content of fish was measured by high‐performance liquid chromatography. It varied between fish species and between facilities, ranging from no measurable content in capelin (Mallotus villosus ) to 7,340 IU vitamin D/kg original matter (OM) in herring (Clupea spp). The average dietary vitamin D content was 311 IU/kg OM at facility 1 and 6,325 IU/kg OM at facility 2, resulting in a vitamin D intake per animal and day without supplementation of 130 IU (25.5 IU/kg body weight BW) and 2,454 IU (438.2 IU/kg BW) respectively. The supplementation of vitamin D elevated significantly the plasma concentrations of 25‐OH‐D by an intraindividual difference of 15 (range ?2 to 59) nmol/L and tCa by 0.1 (0.0–0.3) mmol/L only at facility 2. The exposure to UV‐light raised the blood concentrations of tCa at facility 2 by 0.15 (0.1–0.2) mmol/L, and of iCa and tCa for females at facility 1 by 0.23 (0.13–0.41) mmol/L and 1.8 (1.1–2.5) mmol/L respectively. No significant influence of the study periods (D) and (UVB) was found for the concentrations of 1,25‐(OH)₂‐D at both facilities.     

Effects of maternal treatment with β‐hydroxy‐β‐metylbutyrate and 2‐oxoglutaric acid on femur development in offspring of minks of the standard dark brown type

The aim of the study was to evaluate the effect of the diet, mother type and sex of the offspring on the mechanical and geometric parameters of long bones as well as bone tissue density in minks. Primiparous and multiparous dams were supplemented with β‐hydroxy β‐methylbutyrate (a metabolite of leucine, at the daily dosage of 0.02 g/kg of body weight) and/or 2‐oxoglutaric acid (a precursor of glutamine, at the daily dosage of 0.4 g/kg of body weight) during gestation. The diet did not influence bone tissue density and the length of the humerus. An increase in the length of the femur was noted in male offspring delivered by multiparous dams. The diet resulted in an increase in the weight of the humerus in males from multiparous dams and a decrease in offspring from primiparous dams. Heavier femora were noted in male offspring delivered by both types of dams. The maximum elastic strength of the humerus was higher in the offspring delivered by multiparous than primiparous dams, irrespective of the offspring sex. The diet resulted in reduction in the ultimate strength of the femur in the male offspring delivered by primiparous dams. Only females born by multiparous dams, irrespective of the diet, showed a significant increase in the cross‐sectional area of the humerus, while a significant decline was noted in males delivered by multiparous dams and in all the offspring delivered by primiparous dams. An increase in the cross‐sectional area of the femur was noted in the offspring delivered by multiparous dams, while reduction was observed in the offspring delivered by primiparous dams. These results have shown for the first time that the presence of β‐hydroxy‐β‐methylbutyrate or 2‐oxoglutaric acid in the diet of pregnant primiparous or multiparous dams unambiguously affects the geometry and mechanical properties of offspring's long bones.     

Factors associated with low vitamin D status of Australian alpacas

Objective To investigate factors associated with low vitamin D status of alpacas at pasture in southern Australia. Design A 2‐year survey of alpacas from two farms in South Australia and three in Victoria. Blood samples were collected from 20 to 30 alpacas on each farm on five occasions each year. Breed, gender, age and fleece colour of animals were recorded. Method Blood samples were assayed for plasma 2.5‐hydroxycholecalciferol (25‐OH D₃) and plasma inorganic phosphorus (Pi). Data sets from 802 animal samples were analysed by multiple regression to determine variables associated with low vitamin D status of alpacas. The relationship between plasma 25‐OH D₃ and plasma Pi was also investigated. Results Vitamin D status was significantly affected by month of sampling, with low values in late winter and high values in summer. Plasma vitamin D concentrations increased with age, were higher in alpacas with light fleeces than in those with dark fleeces and were also higher in the Suri than in the Huacaya breed. Plasma Pi concentrations were generally lower in alpacas with plasma 25‐OH D₃ values < 25 nmol/L. Conclusions Young alpacas with dark fleeces are most at risk from vitamin D insufficiency in late winter in southern Australia. The present study indicates that plasma Pi values are not a reliable indicator of vitamin D status of alpacas as assessed by plasma 25‐OH D₃ concentrations.     

The effects of dietary 1, 25-dihydroxycholecalciferol and hydroalcoholic extract of Withania somnifera root on bone mineralisation,strength and histological characteristics in broiler chickens

1. This study was carried out to investigate the effects of 1, 25-dihydroxycholecalciferol (1, 25 (OH)₂ D₃) and a hydroalcoholic extract of Withania somnifera (WS) root on performance, mineral retention, bone mineralisation, bone mechanical and bone histological characteristics of broiler chicks.

2. A 2 × 3 × 2 factorial experiment consisted of a positive control diet with adequate Ca and a negative control diet (Ca concentration reduced by 30%), three concentrations of WS (0, 75 and 150 mg/kg diet), and two concentrations of 1, 25 (OH)₂ D₃ (0 and 0.5 μg/kg diet).

3. A total of 600 male one-d-old Ross 308 broiler chicks were randomly distributed into 60 floor pens, with 10 birds each. Each treatment was replicated 5 times (50 birds). Diets were given ad libitum from one to 42 d of age. On d 21 and 42, one bird per replicate was killed and tibiae were removed.

4. Dietary treatments did not affect feed intake and feed conversion. The maximum body weight gain (2475 g) was noted in birds fed on a diet adequate in Ca and supplemented with 75 mg/kg WS.

5. The Ca and P retentions were significantly higher in birds that were given a diet with 30% less Ca. Supplementation of 150 mg/kg WS significantly improved Ca retention in birds receiving a negative control compared to those given a positive control diet (83.0% vs. 66.3%). Ca retention was significantly improved with the addition of 0.5 μg/kg 1, 25 (OH)₂ D₃ to the diet containing 75 mg/kg WS, regardless of dietary Ca concentration (79.5 vs. 73.3 and 77.9 vs. 68.9).

6. On d 21, birds that received WS had significantly higher tibia Ca compared to those of controls. No significant effects on tibia Ca were noted at 42 d. Birds given a negative control diet supplemented with 75 mg/kg WS and 0.5 μg/kg 1, 25 (OH)₂ D₃ displayed a similar tibia Ca compared to those given only 150 mg/kg WS. Dietary supplementation of 1, 25 (OH)₂ D₃ significantly increased tibia Ca and tibial mineralised zone width in birds at 42 d of age.

7. Tibia shear force and stiffness were significantly increased by supplementation of WS. Administration of 1, 25 (OH)₂ D₃ resulted in a significantly lower width of the proliferative zone at 21 d of age. Reduction of the Ca supply significantly reduced the mineralised zone and cortical thickness at this age.

8. The present study showed that WS supplementation improved Ca retention, bone calcification and mechanical properties with no adverse effects on performance. Also, synergistic effects of WS and 1, 25 (OH)₂ D₃ were observed on Ca retention and bone calcification.     

Effect of n‐3 PUFA‐rich fish oil supplementation during late gestation on kidding,uterine involution and resumption of follicular activity in goat

We have shown that dietary supplementation of n‐3 polyunsaturated fatty acid (n‐3 PUFA)‐rich fish oil (FO) around the breeding time improved the utero‐ovarian functions in the goat. Here, we investigated the effect of FO supplementation during the periparturient period on serum n‐3 PUFA, prostaglandin F_2α metabolite (PGFM), placental expulsion, uterine involution, resumption of oestrus and neonatal vigour. Rohilkhandi goat in advanced gestation (n = 16) was divided into two equal groups. One group was supplemented with FO containing 26% n‐3 long‐chain PUFA at the rate of 156 mg per kg body weight, while the control group was fed isocaloric palm oil (PO) from ?3 to +3 week of kidding. Dietary FO increased serum concentration of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) by 7.3‐ and 6.6‐fold, respectively, after 6 weeks of supplementation. Goats in FO group expelled the foetal membranes 99.1 min earlier (p < .01) than those of PO group. Further, dietary FO significantly decreased the serum PGFM on day 7 post‐partum. However, no difference was found on uterine involution, which was complete by day 20 post‐partum in either group. Resumption of follicular activity by day 5 post‐partum was 87.5% in the FO as compared to 25% in the PO group (p < .05). Similarly, occurrence of behavioural oestrus by day 90 post‐partum was 57.1% in goats of the FO group while none of does was in the PO group (p < .01) expressed oestrus. It was concluded that feeding FO‐rich diet during ?3 to +3 weeks of kidding decreased the PGFM till day 7 post‐partum, hastened the expulsion of foetal membranes and reduced the time from kidding to first post‐partum oestrus in Rohilkhandi does.     

Physiological limit of the daily endogenous cholecalciferol synthesis from UV light in cattle

The link between UV light (sunlight) and endogenous cholecalciferol (vitamin D₃) synthesis in the skin of humans has been known for more than a 100 years, since doctors for the first time successfully used UV light to cure rickets in children. Years later, it was shown that UV light also had a significant effect on the cholecalciferol status in the body of cattle. The cholecalciferol status in the body is measured as the plasma concentration of 25‐hydroxycholecalciferol, which in cattle and humans is the major circulating metabolite of cholecalciferol. Very little is, however, known about the quantitative efficiency of UV light as a source of cholecalciferol in cattle nutrition and physiology. Hence, the aim of this study was to determine the efficiency of using UV light for increasing the plasma 25‐hydroxycholecalciferol concentration in cholecalciferol‐deprived cattle. Twelve cows deprived of cholecalciferol for 6 months were divided into three treatment groups and exposed to UV light for 30, 90 or 120 min/day during 28 days. UV‐light wavelengths ranged from 280 to 415 nm and 30‐min exposure to the UV light was equivalent to 60‐min average summer‐sunlight exposure at 56 °N. Blood samples were collected every 3–4 days and analysed for 25‐hydroxycholecalciferol and cholecalciferol. Results showed that increasing the exposure time from 90–120 min/day did not change the slope of the daily increase in plasma 25‐hydroxycholecalciferol. Hence, it appears that cholecalciferol‐deprived dairy cattle are able to increase their plasma 25‐hydroxycholecalciferol concentration by a maximum of 1 ng/ml/day from UV‐light exposure.     

Effects of 25‐hydroxycholecalciferol supplementation in maternal diets on milk quality and serum bone status markers of sows and bone quality of piglets

Twenty primiparous sows were allocated to two treatments to evaluate the effects of maternal 25‐hydroxycholecalciferol (25OHD₃) supplementation during gestation and lactation on milk quality and serum bone status markers of sows and bone quality of piglets. Immediately after mating, sows were randomly allotted to one of two diets supplemented with 50 µg/kg 25OHD₃ or basal diets without 25OHD₃. Blood and milk samples were obtained. At birth and weaning, 10 piglets from each treatment were killed for bone quality analysis. 25OHD₃‐fed sows provided one more piglet at farrowing and 1.17 more piglets at weaning than sows fed basal diets. The contents of solids not‐fat, protein, fat or lactose were increased in milk from days 7 and 14 of lactation in 25OHD₃‐supplemented sows and 25OHD₃ concentrations in milk were increased by dietary 25OHD₃ supplementation. Dietary 25OHD₃ supplementation increased serum alkaline phosphatase activity but had no effect on serum tartrate‐resistant acid phosphatase activity of sows. Maternal 25OHD₃ supplementation improved bone strength, density and ash content of newborn piglets rather than those of weaning piglets. In conclusion, 25OHD₃ supplementation in maternal diets improved reproductive performance, milk quality and bone status of sows as well as bone quality of newborn piglets.