Effects of additional dosage of vitamin D3, vitamin D2, and 25-hydroxyvitamin D3 on calcium and phosphorus utilization, egg quality and bone mineralization in laying hens

Abstract

Vitamin D is essential for the metabolism of calcium (Ca) and phosphorus (P) in birds. The objective of the study was to evaluate the effect of different isoforms of dietary vitamin D on Ca and P utilization, egg quality, and bone mineralization of laying hens. A total of 42 Lohmann white laying hens at 57 wk of age were randomly assigned to 7 dietary treatments for 6 wk. Dietary treatments were: 3,000 IU/kg Vit D 3 as control, and control with additional 3,000 IU/kg 25-hydroxyvitamin D 3 (T1), 9,000 IU/kg 25-hydroxyvitamin D 3 (T2), 3,000 IU/kg vitamin D3 (T3), 9,000 IU/kg vitamin D 3 (T4), 3,000 IU/kg of vitamin D 2 (T5), or 9,000 IU/kg of vitamin D 2 (T6). Egg production and egg quality were measured weekly. Fecal samples were collected at weeks 2 and 6 to measure Ca and P utilization. After 6 wk, the left tibia and femurs were collected to measure bone mineral density (BMD) and bone mineral content (BMC). A 1-way ANOVA with Tukey HSD means separation test was used for statistical analysis. There were no significant differences in egg production, egg quality, BMD, or BMC of tibia and femurs among the treatments ( P > 0.05). T6 significantly reduced feed intake ( P < 0.05). The apparent total tract digestibility (ATTD) of Ca was higher ( P < 0.012) in treatments supplemented with additional vitamin D, irrespective of forms. The ATTD of P was higher ( P < 0.0001) in T5 compared to the other treatments at both time points. The utilization of Ca and P by laying hens can be improved through the addition of different isoforms of vitamin D in diets. However, additional vitamin D supplementation to laying hens, regardless of forms, had no effect on either bone mineralization or measures of egg quality.

Role of long-term supplementation of 25-hydroxyvitamin D3 on egg production and egg quality of laying hen

“…The lack of the effects of 25OHD on egg production in older hens may be due to the conversion efficiency in the kidney, which was inadequate to convert 25OHD to 1,25OHD during the late laying stage ( Abe et al., 1982 ). In contrast to our findings, a number of other studies failed to find any beneficial effects on egg production in laying hens or broiler breeders ( Koreleski and Świątkiewicz, 2005 ; Torres et al., 2009 ; Käppeli et al., 2011 ; Mattila et al., 2011 ; Adhikari et al., 2020 ). However, in these studies, 25OHD was not included in the diets during the rearing period or was supplemented during certain laying periods, instead of the entire laying period.…”

“…It is 2- to 4-fold more active compared with vitamin D 3 in chicken diets ( Soares Jr. et al., 1995 ; Atencio et al., 2005 ). However, previous studies of 25OHD on laying hens have shown either no effects ( Roland and Harms, 1976 ; Keshavarz, 2003 ; Käppeli et al., 2011 ; Mattila et al., 2011 ; Nascimento et al., 2014 ; Adhikari et al., 2020 ) or beneficial effects ( Koreleski and Świątkiewicz, 2005 ; Torres et al., 2009 ; Silva, 2017 ) on eggshell quality and/or egg production. Inconsistent results among these studies may be due to differences in 25OHD treatment duration, treatment timing, and laying stage.…”

Nutritional significance of amino acids, vitamins and minerals as nutraceuticals in poultry production and health – a comprehensive review

“…Irrespective of form, the apparent total tract digestibility of calcium was higher in diets enriched with vitamin D. The apparent total tract digestibility of phosphorus was higher in 3,000 IU/kg feed of vitamin D 2 compared to the other treatments. The utilization of calcium and phosphorus by laying birds can be enhanced by the addition of different sources of vitamin D in rations (Adhikari et al 2020). Finally, the deficiency consequences of this vitamin are serious, including rickets, poor growth and immune response and also reduction of the production.…”

The adaptability of Hy-Line Brown laying hens to low-phosphorus diets supplemented with phytase

“…In addition, phytase, the most widely used dietary exogenous enzyme in animal production ( Adeola, 2011 ), breaks down phytate-phosphate from plant feed ingredients and dramatically reduces the animals' requirement for inorganic phosphorus ( Fernández et al., 2019 ). Interestingly, while the aforementioned technologies have repeatedly been documented in the literature, it still remains unclear in the field that how much inorganic phosphate rock will need be supplemented into poultry diets when those technologies are applied ( Li et al., 2015 , Adhikari et al., 2020 , Ren et al., 2020 ).…”