The effects of forced molt treatment on blood biochemicals in hens

A study was conducted to determine the effects of an environmentally induced force molt treatment on concentrations and daily variations of selected serum biochemicals during early molt. Laying hens were placed into two environmental control chambers. In one chamber, control (Con) laying hens were maintained on long photoperiods of 19 hr of light daily to maintain egg production. In the other chamber, early molt (EM) hens were exposed to short photoperiods of 6 hr of light daily to decrease egg production. After 2 weeks in the chambers, feed was withdrawn from EM hens for 2 days to initiate molt. Three days after feed was restored, hens from both groups were blood sampled every 2 hr for 2 days for selected serum biochemical analyses. Serum concentrations of calcium (Ca), inorganic phosphate (P), glutamic pyruvic transaminase (GPT), and albumin (Alb) were depressed in EM hens. Serum concentrations of alkaline phosphatase (Alk P), lactic acid dehydrogenase (LDH), glutamic oxaloacetic transaminase (GOT), glucose (Glu), cholesterol (Chol), and globulin (Glob) were elevated in EM hens. Daily temporal rhythms of Ca, Glu, total protein (TP), and Alb were found in both hen groups. These temporal changes were independent of force molt treatment. Serum GOT was positively correlated with nuclei free liver corticosteroids (LCS) and negatively associated with plasma corticosterone in Con hens. Serum GOT was positively correlated with nuclei free LCS in EM hens.