Classic and Non-Classic Effects of the Duration of Supplementation of 25-Hydroxicholecalciferol in Broiler Chicken Diets

Simple Summary

Genetic programs of modern commercial-type broiler chickens are based on growth performance parameters associated with muscular growth, feed efficiency, and meat and breast yield. Therefore, highly bioavailable vitamin D₃ to sustain optimal muscle and bone development is necessary. In the present study the effect of different durations of supplementing of 25-hydroxycholecalciferol (25(OH)D₃) in broiler chickens was evaluated. Growth performance response, carcass and cuts yield, bone resistance, plasma concentration of 25(OH)D₃, and expression of the mTOR gene were evaluated. The use of 25(OH)D₃ in the diets for broilers during different feeding periods did not influence growth performance but increased the plasma concentration of 25(OH)D₃, and increased breast yield as the duration of the supplementation was extended. The supplementation of 25(OH)D₃ increased breast yield and protein deposition in the breast muscle which may have been a result of the epigenetic changes caused by this vitamin D (Vit D) metabolite.

Abstract

The present study aimed to determine the effect of different times of supplementation of 25-hydroxycholecalciferol (25(OH)D₃) in broiler chickens on the performance, carcass and cuts yield, bone resistance, plasma concentration of 25(OH)D₃, and expression of the mTOR gene. The treatments were a control diet (CD) supplemented with 3000 IU vitamin D₃/kg of feed from 1 to 46 d, or the CD + 2760 IU (69 mcg) of 25(OH)D₃/kg of feed from 1 to 21 d, from 1 to 35 d, or from 1 to 46 d. The period of supplementation of 25(OH)D₃ did not affect the growth performance of broilers, but the breast meat yield was linearly increased in response to increasing days of supplementation (p < 0.05). Birds supplemented with 25(OH)D₃ at the time of the analysis showed an increase (p < 0.05) in the plasma concentration of 25(OH)D₃ when compared to non-supplemented birds. The mTOR gene expression (p < 0.05), and breast protein deposition (p < 0.05) presented a quadratic response related to the supplementation period of 25(OH)D₃. The fat content of the breast linearly decreased (p < 0.05) as the period of supplementation was extended. The results also showed a positive linear correlation between mTOR expression and 25(OH)D₃ plasma levels (r = 0.593; p < 0.05).

Effects and interaction of dietary calcium and nonphytate phosphorus for slow-growing yellow-feathered broilers between 56 and 84 d of age

This experiment investigated the effect and interaction of dietary calcium (Ca) and nonphytate phosphorus (NPP) on growth performance, tibial characteristics, carcass traits, and meat quality for slow-growing yellow-feathered broilers during 56 to 84 d of age. A 3 × 3 factorial arrangement was used, and 720 56-day-old broilers were randomly divided into 9 groups and fed with diets containing different levels of Ca (0.70, 0.80, 0.90%) and NPP (0.30, 0.35, 0.40%) for 28 d. The dietary Ca level affected the ADFI of yellow-feathered broilers (P < 0.05), and the ADFI of birds fed with 0.90% Ca was increased (P < 0.05) compared with that of birds fed with 0.70% Ca.  Birds received 0.35 or 0.40% NPP had higher final BW, ADG, and ADFI than those fed with 0.30% NPP (P < 0.05). The tibial diameter of birds fed with 0.80% Ca was increased compared with that of other groups (P < 0.05). The dietary NPP level did not affect tibial characteristics (P > 0.05). The dietary Ca level did not affect carcass traits (P > 0.05). When broilers were fed with 0.30% P, the semieviscerated percentage was increased compared with birds fed with 0.40% NPP (P < 0.05). The dietary Ca level had significant effects on the L∗ value and shear force of the breast muscle, and the dietary NPP level affected the L∗ value and drip loss of the breast muscle (P < 0.05). Furthermore, the effect of interaction between the level of Ca and NPP was observed on the L∗ and a∗ value (P < 0.05). In conclusion, dietary Ca had influence on performance, tibial characteristics, and meat quality of yellow-feathered broilers, and dietary NPP affected performance, tibial characteristics, and carcass traits. Furthermore, the effect of interaction between the dietary Ca and NPP level was observed on carcass traits and meat quality. Considering all aforementioned indicators, 0.80% Ca and 0.35% NPP were recommended for slow-growing yellow-feathered broilers aged 57 to 84 d of age.

Effects of source and level of in ovo-injected vitamin D3 on the hatchability and serum 25-hydroxycholecalciferol concentrations of Ross 708 broilers

Effects of the in ovo injection of vitamin D3 (D3) and 25-hydroxycholecalciferol (25OHD3) on broiler embryo serum 25OHD3 concentrations, hatchability, and hatchling somatic characteristics were determined. Eggs from a 35-wk-old commercial Ross 708 broiler breeder flock were set in a single-stage incubator with 11 treatments represented on each of 8 incubator tray levels (blocks). Each treatment group within a flat on each tray level contained 30 eggs. Control treatments were noninjected and diluent injected. Vitamin treatments were commercial diluent containing 0.6 μg D3, 0.6 μg 25OHD3, 0.6 μg D3 + 0.6 μg 25OHD3, 1.2 μg D3, 1.2 μg 25OHD3, 1.2 μg D3 + 1.2 μg 25OHD3, 2.4 μg D3, 2.4 μg 25OHD3, or 2.4 μg D3 + 2.4 μg 25OHD3. At 432 h of incubation (hoi), 50-μL solution volumes were injected. Blood samples were collected at 462 hoi for serum 25OHD3 analysis, and hatchability of injected live embryonated eggs (HI) was determined at 492 and 516 hoi. At 516 hoi, hatchling yolk-free BW and weights of the liver and yolk sac were determined. Percentage of yolk moisture and dry mater was calculated. At 492 and 516 hoi, HI did not differ between treatments. Embryos that received 1.2 μg or more of either vitamin D3 source alone or in combination had higher serum 25OHD3 concentrations than those that were injected with diluent alone or diluent containing 0.6 μg of D3. Hatchlings that received 1.2 or 2.4 μg of 25OHD3 had higher percentage of yolk dry matter or lower percentage of yolk moisture levels than noninjected controls and those that received D3 alone at any level. These results indicate that the in ovo injection of either vitamin D3 source at levels equal to or higher than 1.2 μg resulted in serum 25OHD3 concentrations that were higher than that of noninjected controls. In addition, the in ovo injection of 1.2 μg or higher of either vitamin D3 source did not negatively affect broiler HI or chick quality.

Vitamin D3 enhanced intestinal phosphate cotransporter genes in young and growing broilers

The influence of dietary vitamin D₃ (VD3) levels on growth, bone performance, and duodenal type IIb sodium-dependent phosphate cotransporter (NaPi-IIb) genes in broiler chicken were studied. One-day-old male Ross308 broilers (n = 432) were allocated into 6 treatment groups with each group consisting of 6 cage pens. Each treatment group received diet containing different amounts of VD3 (80, 200, 500, 1,250, 3,125, or 7,813 IU per kg of diet) from a day-old to 31 D of age. Dietary available phosphorus and calcium were kept the same across all treatments in each phase. At 14 D, influence of VD3 on BW gain was found in the birds that received VD3 of 3,125 IU/kg and 200 IU/kg (P < 0.05). Toe ash and tibia ash linearly increased (P < 0.05) at 14 D with increase in dietary VD3_. There was no significant influence of dietary VD3 on tibia breaking strength. In both phases, relative expression of duodenal NaPi-IIb linearly increased (P < 0.01) with increase in dietary VD3. At 14 D, highest expression of 3.2 folds was observed in birds treated with VD3 at 7,813 IU/kg of feed. At 31 D, birds that received VD3 levels of 3,125 and 7,813 IU/kg of feed showed 2.9 folds higher in NaPi-IIb expression compared with those fed lowest level of VD3 at 80 IU/kg of feed. When dietary calcium and phosphorus were maintained at the standard requirement, increase in dietary VD3 did not improve growth performance. For optimum growth and bone characteristics, dietary inclusion of VD3 at 500 IU/kg was adequate for both starter and grower broiler diets. Vitamin D₃ enhanced the expression of NaPi-IIb at higher doses and thus improving the tibia ash content in high VD3 treatment groups. This study reported for the first time an increased in the expression of duodenal NaPi-IIb in 31-day-old broilers in response to high dietary VD3 levels.

The effects of in ovo injected vitamin D3 sources on the eggshell temperature and early posthatch performance of Ross 708 broilers,. Poult Sci 2019;99:1357-1362. [PMID: 32115025 PMCID: PMC7587651 DOI: 10.1016/j.psj.2019.10.055]

The effects of in ovo injected vitamin D₃ source on eggshell temperature (ET) and performance of broilers through 14 D of age (doa) were investigated. Eggs from a 35-wk-old commercial Ross 708 broiler breeder flock were set in a single-stage incubator with 4 treatments representing each of 12 incubator tray levels (blocks). At 432 h of incubation (hoi), noninjected and diluent-injected (50 μL) groups were control treatment groups. Vitamin treatments in the commercial diluent were as follows: 2.4 μg of vitamin D₃ (D₃) or 25-hydroxylcholecalciferol (25OHD₃). After injection, ET readings were recorded (435, 441, 453, 459, and 465 hoi) by infrared thermometry. Hatchability, hatchling BW, and percentage of male and female hatchlings were determined at 502 hoi. Equal numbers of male and female chicks were placed in each pen and grown out for 14 doa. On a per-pen basis, BW was recorded after hatching at day 7 and 14 doa, and BW gain, average daily BW gain, feed intake (FI), and feed conversion ratio (FCR) were calculated between 0 to 14 doa. The ET of eggs significantly fluctuated during the postinjection time period; however, the type of vitamin D₃ source injected did not affect ET. Nevertheless, the injection of 25OHD₃ resulted in a lower late embryo mortality than the diluent and D₃ injection treatments. In addition, birds that received 25OHD₃ had a lower FI and FCR than birds in all other treatments. In conclusion, the in ovo injection of 25OHD₃ has the potential to improve early posthatch broiler performance without affecting ET.

Developing a novel oral vitamin D3 intake bioassay to re-evaluate the vitamin D3 requirement for modern broiler chickens

The present study was conducted to develop a non-traditional vitamin D3 (D3) intake bioassay with the objective of increasing the precision of D3 delivery to the chickens. For this purpose, newly hatched chickens (5 birds per cage) were allocated in battery brooders and randomly distributed into 8 treatments and 6 replicates per treatment. A basal corn-soy diet devoid of D3 containing calculated calcium and non-phytate phosphorus concentrations of 0.90 and 0.45%, respectively, was fed throughout a 21-D period. The first 9 D of the study served to deplete the maternal stores of D3 followed by a 12-h fasting period. From day 10 to the end of the trial, the birds were gavaged with graded levels of D3 obtained from a highly purified pharmaceutical grade D3 standard (99.8%) purchased from Sigma-Aldrich and dissolved in corn oil. Daily gavage treatments were based on estimated intake of 0, 50, 100, 200, 400, 800, 1,600, and 3,200 IU D3/kg of feed consumed over the last 12 D of the study. Precise cholecalciferol intake per kg of diet was adjusted based on actual daily feed intake per pen of birds. Performance data were evaluated from day 10 to 21. Percent tibia bone ash (TBA), tibia breaking strength (TBS), total mineral content, and total bone mineral density were obtained at day 21. The D3 treatments improved (P < 0.05) weight gain and feed efficiency. There was no linear or quadratic effect for any of the productivity performance variables. Graded levels of D3 improved (P < 0.05) TBA and TBS. Both were linearly increased (P < 0.05) in response to graded levels of D3. A quadratic response was observed for TBS only. Under the conditions of the present experiment and the average of 3 regression models, the D3 requirement for starter broilers was estimated at 285 IU D3/kg of feed when bone mineralization responses (TBA and TBS) were used as criteria to estimate the requirement.

A reassessment of the vitamin D requirements of modern broiler genotypes

We hypothesized that performance and bone mineralization of 2 broiler lines will benefit from increasing vitamin D (vitD) supplementation above current commercial levels and by partial substitution of D3 by 25-OH-D3. Male Ross 308 and 708 chicks (n = 576), were offered diets with low (LD; 1,000), medium (MD; 4,000) or high levels of D3 (HD; 7,000 IU/kg), and medium levels of vitD where the majority of D3 was substituted by 25-OH-D3 (25MD; 1,000 D3+3,000 25-OH-D3 IU/kg). Performance was measured at the end of starter (day 10), grower (day 24), and finisher periods (day 38). Three birds per pen were dissected at the end of each period to assess tibia and femur ash percentage (%), ash weight, bone breaking strength (BBS), and serum levels of 25-OH-D3. Remaining birds were gait scored (GS) at day 37 of age. Genotype and diet did not interact for any trait, whilst performance was not affected by diet. Ross 708 had lower body weight (P < 0.005), higher feed conversion ratio over the grower period (P < 0.05), similar levels of 25-OH-D3, but higher GS (P < 0.05) than Ross 308. Serum 25-OH-D3 levels were affected by diet at the end of the starter and grower periods (P < 0.05), being lowest for LD and highest for 25MD. Diet affected GS (P < 0.01), being higher in LD than 25MD. Femur ash % was higher at the end of the starter and grower periods for 25MD than LD and for both HD and 25MD than LD (P < 0.05). Femur and tibia ash weight were higher for 25MD in comparison to LD birds (P < 0.05) at the end of the grower period. Femur and tibia BBS were higher (P < 0.05) for 25MD in comparison to LD at the end of the grower and finisher periods, respectively. Overall, effects of vitD supply were more pronounced for femur than for tibia mineralization. Results do not suggest supplementation of vitD above current maximum levels and support partial substitution by 25-OH-D3.

Evaluation of Relative Bioavailability of 25-Hydroxycholecalciferol to Cholecalciferol for Broiler Chickens

This study was conducted to evaluate the relative bioavailability (RBV) of 25-hydroxycholecalciferol (25-OH-D₃) to cholecalciferol (vitamin D₃) in 1- to 21-d-old broiler chickens fed with calcium (Ca)- and phosphorus (P)-deficient diets. On the day of hatch, 450 female Ross 308 broiler chickens were assigned to nine treatments, with five replicates of ten birds each. The basal diet contained 0.50% Ca and 0.25% non-phytate phosphorus (NPP) and was not supplemented with vitamin D. Vitamin D₃ was fed at 0, 2.5, 5.0, 10.0, and 20.0 μg/kg, and 25-OH-D₃ was fed at 1.25, 2.5, 5.0, and 10.0 μg/kg. The RBV of 25-OH-D₃ was determined using vitamin D₃ as the standard source by the slope ratio method. Vitamin D₃ and 25-OH-D₃ intake was used as the independent variable for regression analysis. The linear relationships between the level of vitamin D₃ or 25-OH-D₃ and body weight gain (BWG) and the weight, length, ash weight, and the percentage of ash, Ca, and P in femur, tibia, and metatarsus of broiler chickens were observed. Using BWG as the criterion, the RBV value of 25-OH-D₃ to vitamin D₃ was 1.85. Using the mineralization of the femur, tibia, and metatarsus as criteria, the RBV of 25-OH-D₃ to vitamin D₃ ranged from 1.82 to 2.45, 1.86 to 2.52, and 1.65 to 2.05, respectively. These data indicate that 25-OH-D₃ is approximately 2.03 times as active as vitamin D₃ in promoting growth performance and bone mineralization in broiler chicken diets.

Balanço de minerais e desempenho em frangos de corte aos 21 dias de idade alimentados com rações contendo Solanum malacoxylon

ResumoEstudou-se o desempenho produtivo e as quantidades de cálcio (Ca), fósforo (P), magnésio (Mg), potássio (K) e sódio (Na) nas excretas e carcaças de frangos de corte aos 21 dias de idade alimentados com adição de Solanum malacoxylon (SM) nas rações. Adotou-se delineamento inteiramente casualizado, com três tratamentos: 0,0, 2,5 e 5,0g de SM/kg de ração, sendo cinco repetições e quatro aves por unidade experimental. O uso de 5,0 g de SM/kg de ração reduziu o ganho de peso e piorou a conversão alimentar, embora o consumo não tenha sido influenciado. A inclusão da planta não afetou (p>0,05) os teores de cálcio, magnésio, potássio e sódio nas excretas e, consequentemente, na absorção desses minerais. A composição mineral das carcaças foi alterada, sendo as concentrações de Na, Mg e K, influenciadas. Recomenda-se a adição de até 2,5g de SM/kg de ração para frangos de corte até 21 dias de idade.