Effect of varying levels of dietary vitamin D3 on turkey hen egg production, fertility and hatchability, embryo mortality and incidence of embryo beak malformations

Effects of the in ovo injection of vitamin D3 and 25-hydroxyvitamin D3 in Ross 708 broilers subsequently fed commercial or calcium and phosphorus-restricted diets. I. Performance, carcass characteristics, and incidence of woody breast myopathy1,2,3

Effects of the in ovo-injection of vitamin D₃ (D₃) and 25-hydroxyvitamin D₃ (25OHD₃) on broiler performance, carcass characteristics, and woody breast myopathy (WBM) incidence were investigated. Live embryonated Ross 708 broiler hatching eggs (2,880) were randomly assigned to one of the following in ovo injection treatments: (1) diluent (50 μL); diluent (50 μL) containing either (2) 2.4 μg D₃; (3) 2.4 μg 25OHD₃; or (4) 2.4 μg D₃ + 2.4 μg 25OHD₃. Eggs were injected at 18 d of incubation (doi) using an Inovoject multiegg injector. At hatch, 18 male chicks were randomly placed in each of 6 replicate pens belonging to each in ovo injection and, dietary treatment combination. Birds were fed either a commercial diet or a diet restricted in calcium and phosphorous (ReCaP) content by 20% for the starter, grower and finisher dietary phases. Broiler performance was determined in each dietary phase and breast muscle yield was also determined at 14 and 40 d of age (doa). At 41 and 46 doa, birds were processed for determination of WBM, carcass weight, and the absolute and relative (% of carcass weight) weights of various carcass parts. Compared to birds fed the commercial diet, birds fed ReCaP diets experienced a reduction in performance from 14 to 40 doa, in breast meat yield at 41 and 46 doa, and in WBM at 41 and 46 doa. At 14 and 40 doa, breast meat yield in birds that received an in ovo injection of 25OHD₃ alone was higher compared to birds that received diluent alone or a combination of D₃ and 25OHD₃. Lower WBM incidence in ReCaP-fed birds was associated with a lower breast weight. An increase in breast meat yield in response to 25OHD₃ alone may be due to improved immunity and small intestine morphology. However, further study is needed to determine the aforementioned effects.

Improvement in the performance and inflammatory reaction of Ross 708 broilers in response to the in ovo injection of 25-hydroxyvitamin D3

The effects of the in ovo administration of vitamin D₃ (D₃) and its metabolite, 25-hydroxyvitamin D₃ (25OHD₃)_, on the performance, breast meat yield, and inflammatory responses of broilers fed commercial diets were investigated. Live embryonated Ross 708 broiler hatching eggs were randomly assigned to one of the following 5 in ovo injection treatments at 18 d of incubation: 1) noninjected; 2) diluent; diluent containing 3) 2.4-μg D₃, 4) 2.4-μg 25OHD₃, or 5) 2.4-μg D₃ + 2.4-μg 25OHD₃. A 50-μL solution volume of each prespecified treatment was injected into each egg using an Inovoject multiegg injector. At hatch, 18 male chicks were randomly assigned to each of 30 floor pens. The BW, BW gain, feed intake, and feed conversion ratio of the birds were determined in each dietary phase. At 14, 28, and 39 d of posthatch age (doa), plasma α-1-acid glycoprotein (AGP) levels in 1 bird in each of 6 replicate pens per treatment were determined at 14 and 39 doa. The pectoralis major and minor weights of those same birds were also determined. The remaining birds were processed at 43 doa, and the weights of their processing parts were determined. At 39 doa, the in ovo injection of 25OHD₃ alone decreased plasma AGP concentrations in comparison with the noninjected, diluent, and D₃-alone treatment groups. In addition, birds that received 25OHD₃ alone had a greater BW at 42 doa than birds in the noninjected, diluent, and D₃-alone treatment groups. At 39 and 43 doa, breast meat yield was increased in response to the in ovo injection of 25OHD₃ alone in comparison to all other treatments. These results indicate that the in ovo injection of 2.4 μg of 25OHD₃ resulted in an improvement in the performance and inflammatory responses of broilers. A reduction in the inflammatory response subsequent to the in ovo injection of 2.4 μg of 25OHD₃ may have led to an increase in broiler performance.

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.

Why did the dinosaurs become extinct? Could cholecalciferol (vitamin D3) deficiency be the answer?

Palaeontological deductions from the fossil remnants of extinct dinosaurs tell us much about their classification into species as well as about their physiological and behavioural characteristics. Geological evidence indicates that dinosaurs became extinct at the boundary between the Cretaceous and Paleogene eras, about 66 million years ago, at a time when there was worldwide environmental change resulting from the impact of a large celestial object with the Earth and/or from vast volcanic eruptions. However, apart from the presumption that climate change and interference with food supply contributed to their extinction, no biological mechanism has been suggested to explain why such a diverse range of terrestrial vertebrates ceased to exist. One of perhaps several contributing mechanisms comes by extrapolating from the physiology of the avian descendants of dinosaurs. This raises the possibility that cholecalciferol (vitamin D₃) deficiency of developing embryos in dinosaur eggs could have caused their death before hatching, thus extinguishing the entire family of dinosaurs through failure to reproduce.

Effects of maternal nutrition on hatchability

The effects of dietary factors on the development and viability of avian embryos have been extensively documented. A good nutritional status of the parent birds is crucial to the transfer to the egg of an adequate, balanced supply of nutrients required for normal development of the embryo. The consequences to the embryo may be lethal if the egg contains either inadequate, excessive, or imbalanced levels of nutrients. As nutritional deficiencies or excesses occur, it is common for the effects on the embryo to also become more severe and to occur at earlier stages of development. The type of nutritional stress signs visible in the embryo often depend upon the severity of the maternal nutritional stress. Diseases, parasitic infections, toxins, poisons, or drugs may also cause nutritional or pseudonutritional problems with hatchability.

Effects of supplementary vitamin D3 on egg production of two strains of Japanese quail and growth of their progeny

Two strains (University of Saskatchewan, white egg and wild type) of mature Japanese quail (Coturnix coturnix japonica), following a 4-week depletion period, were fed one of four diets varying in supplementary vitamin D3: a) no supplementary vitamin D3, b) National Research Council (NRC, 1977) recommended level of 1,200 IU vitamin D3/kg feed, c) 10 times, NRC levels, and d) 100 times NRC levels for 4 weeks. Egg production, egg weight, number of softshelled eggs, body weight, and feed consumption were not affected by vitamin D3 treatment. Hatchability of the white egg strain was not affected by vitamin D3 treatment. Hatchability in the wild type strain was reduced in those birds consuming diets unsupplemented with vitamin D3 although not significantly. Tibia ash was not affected by vitamin D3 treatment. Progeny from hens receiving no supplemental vitamin D3 were smaller throughout a 5-week growth period; however, feed consumption and percentage tibia ash content were similar to those of progeny from the other treatments. Progeny fed 480 IU vitamin D3/kg feed were larger, had higher tibia ash, and similar feed consumption compared with those fed a diet with no added vitamin D3.

Effects of vitamin D3, calcium, and phosphorus on growth and bone development of market turkeys

A study was undertaken to determine the effects of maternal and poult nutrition on poult growth and bone development through to market age. Nicholas Large White turkey hens (200) were fed diets with 300, 900, or 2700 IU vitamin D3/kg from day-old to 37 weeks of age. Male poults (649 from Hatch 1 and 555 from Hatch 2) were fed diets containing .6 or 1.2% Ca; .4 or .8% available P; and 300, 900, or 2700 IU vitamin D3/kg to 4 weeks (Hatch 1) or 2 weeks of age (Hatch 2) in a complete factorial design. All Hatch 2 poults were given a "therapeutic" diet from 2 to 4 weeks, followed by normal grower diets from 4 to 24 weeks of age. Increasing the level of vitamin D3 in the hen diet increased weight at hatching and at 2 and 4 weeks, decreased mortality from 0 to 2 weeks, and increased bone ash percent and breaking strength and decreased the severity of rickets score at 2 weeks. Increasing the levels of Ca, P, and vitamin D3 in the poult diet gave reduced mortality from 0 to 2 weeks, increased weight at 2 and 4 weeks, increased bone ash percent and breaking strength, and decreased severity of rickets score at 2 and 4 weeks. Carcass fleshing score at 24 weeks was improved with 1.2% Ca. Conformation score and percent grade A carcasses increased linearly with level of vitamin D3 in the starter diet and were also improved by increasing the vitamin D3 in the breeder diet.