Release of β-endorphin, adrenocorticotropic hormone and cortisol in response to machine milking of dairy cows
نویسندگان
چکیده
AIM The present study was undertaken with the objective to obtain insight into the dynamics of the release of β-endorphin, adrenocorticotrophic hormone (ACTH) and cortisol in response to machine milking in dairy cows. MATERIALS AND METHODS A total of 10 healthy multiparous lactating Italian Friesian dairy cows were used in the study. Animals were at the 4(th)-5(th) month of pregnancy and were submitted to machine milking 2 times daily. Blood samples were collected in the morning: In baseline conditions, immediately before milking and after milking; and in the early afternoon: In baseline conditions, before milking and after milking, for 2 consecutive days. Endocrine variables were measured in duplicate, using a commercial radioimmunoassay for circulating β-endorphin and ACTH concentrations and a competitive enzyme-linked immunoassay for cortisol concentration. RESULTS Data obtained showed a similar biphasic cortisol secretion of lactating dairy cows, with a significant increase of cortisol concentration after morning machine milking, at both the 1(st) and the 2(nd) day (p<0.05), and a decrease after afternoon machine milking at the 2(nd) day (p<0.01). One-way RM ANOVA showed significant effects of the machine milking on the cortisol changes, at both morning (f=22.96; p<0.001) and afternoon (f=15.10; p<0.01) milking, respectively. Two-way RM ANOVA showed a significant interaction between cortisol changes at the 1(st) and the 2(nd) day (f=7.94; p<0.0002), and between the sampling times (f=6.09; p<0.001). Conversely, no significant effects of the machine milking were observed on β-endorphin and ACTH changes, but only a moderate positive correlation (r=0.94; p<0.06) after milking stimuli. CONCLUSIONS A wide range of cortisol concentrations reported in this study showed the complex dynamic patterns of the homeostatic mechanisms involved during machine milking in dairy cows, suggesting that β-endorphin and ACTH were not the main factors that caused the adrenocortical response to milking stimuli.
منابع مشابه
Cortisol and ACTH release in dairy cows in response to machine milking after pretreatment with morphine and naloxone.
The aim ot the study was to examine the effect of morphine and naloxone pretreatment on cortisol and ACTH concentrations in response to machine milking in dairy cows. In the first part of the experiment, the effects of i.v. morphine doses (0, 21, 70 and 210 mg, one dose each day) 10 min before morning milking were studied in six Brown Swiss dairy cows. In the second part, four cows were treated...
متن کاملNormal and disturbed milk ejection in dairy cows.
More than 80% of the milk stored in the udder, i.e. the alveolar fraction, only available after milk ejection is induced by the release of oxytocin and myoepithelial contraction. Milk ejection is induced by tactile teat stimulation, either manually or by the milking machine. The time from the start of a tactile stimulation until the occurrence of milk ejection spans from 40 s up to more than 2 ...
متن کاملHormone release and behavior during suckling and milking in Gir, Gir x Holstein, and Holstein cows.
There are several different milking management systems in Latin America, because Gir cattle are reputed to be easily stressed and not well adapted to machine-milking. This paper, therefore, provides an overview of hormone release and behavior during suckling and milking in Gir cows and their cross-bred offspring. Several experiments were performed to study oxytocin release during exclusive suck...
متن کاملInhibition of oxytocin release during repeated milking in unfamiliar surroundings: the importance of opioids and adrenal cortex sensitivity.
The aim of this study was to test if the opioid antagonist naloxone has a beneficial effect on normalization of oxytocin (OT) release during repeated milking of cows in unfamiliar surroundings. One control milking without naloxone treatment in all cows was performed in the familiar parlour. For four successive evening milkings, cows were transported to, and milked in, the operating theatre of t...
متن کاملPhysiological and Behavioral Responses of Dairy Cows which Milked with Portable parlor
In normal use, milking parlor can cause the release of oxytocin through neuroendocrine reflex, but the use of milking parlor sometimes cause stress and lead to a decrease in milk production. In Indonesia at this time, traditional milking by hand is still widely used by dairy farmers. The purpose of this study is to investigate the use of milking parlor to the physiological and behavioral respon...
متن کامل