Plasma calcium, phosphorus, 25-dihydroxyvitamin D3, and 1-25-dihydroxyvitamin D3 of hens with fatty liver syndrome.

Plasma was obtained from normal laying hens, 30 weeks of age, and from laying hens, 60 weeks of age, with fatty liver syndrome (FLS). The 60-week-old hens were divided into two groups based on whether they were laying or nonlaying. Plasma phosphorus and calcium was significantly higher for hens with FLS. The younger hens had significantly lower 25-dihydroxyvitamin D3 (25-OH-D3) plasma levels than the older hens. The older hens that were laying had significantly lower 25-OH-D3 plasma levels than the nonlaying hens. Old nonlaying hens with FLS had lower 1, 25-OH-D3 than young hens or old laying hens with FLS; however, the levels were not different for the two groups of laying hens.