Effects Of Cysteamine Compound On Performances Of Lactating Cow During Hot Summer

The objectives of the present study were to reveal the effects of cysteamine compound on performances and endocrine hormones of lactating cow during hot summer, and look for new solution to relieve heat stress of lactating dairy cow. Series I : Effects of cysteamine compound on performances of late lactating cow during hot summer: The aim of this study was to investigate the effects of cysteamine compound (Lactonin)on milk production of late lactating cows during hot summer when the temperature humility index (THI) was higher than 76 and cows were suffered from heat stress. In this experiment 96 black and white dairy cows at late-lactation(210 d postpartum) was assigned into 4 groups (G), based on milk yield (M) prior to the experiment (Gl<24, 2432 kg/d). Each group was further divided into subgroups of cysteamine treatment (CSC, n= 49) and Control (n=47). In CSC of G1 the rectal temperature decreased (P<0.05)however milk yield, fat-corrected milk, milk fat and feed conversion rate (FCR) increased (P<0.05). These were companied with trendy (0.05