Associations among milk production traits and glycosylated haemoglobin in dairy cattle: importance of lactose synthesis potential

Abstract Glucose is the major precursor of lactose synthesis in the mammary gland. Lactose the major carbohydrate and osmolyte of milk, controls milk volume and its concentration. Glycosylated haemoglobin (HbG) is a retrospective measure of mean blood glucose level and it is largely unaffected by recent physiological conditions and environmental events. The purposes of this study were to determine the correlations between lactose traits and other milk production traits in dairy cattle and to investigate whether HbG level can be correlated with milk and lactose production traits. Here, HbG percentage, milk and lactose production traits including milk yield, lactose, protein, SNF, total solid and fat percentages and yields were measured in 485 second calved Iranian Holstein cattle. Statistically significant negative correlations were established between HbG and milk yield (r=−0.88), lactose yield (r=−0.83), SNF yield (r=−0.81), protein yield (r=−0.79) and total solid yield (r=−0.74). Positive correlations were established between lactose yield and milk (r=0.96), protein (r=0.81), SNF (r=0.92) and total solid (r=0.79) yields. The negative correlation between HbG and milk and total lactose production is probably related to the higher glucose demands in the lactating mammary gland of more productive cows. The positive correlation between lactose yield and milk, protein, SNF and total solid yield indicates that the level of lactose synthesis influences milk production traits in ways other than merely via its osmolytic action

Clinical evaluation of repeated propofol total intravenous anesthesia in dog

This current study designed to evaluate any possible changes in required doses and other cardiopulmonary findings after repeated propofol total intravenous anesthesia (TIVA) in dog. The study was conducted in 6 healthy sheepdogs, weight between 16.5 and 28 kg. Anaesthesia induced by 8 mg kg -1 of propofol and maintained by continuous propofol (0.3 mg/kg/min) infusion in saline solution. All dogs received three times of propofol anaesthesia with the same protocol in a cross over design. As the animals in first, second and third time of anaesthesia allocated into groups 1, 2 and 3, respectively. Heart Rate (HR), rectal temperature (Temp), blood oxygen saturation (SpO2) by pulse oximetry and non invasive arterial blood pressures were measured. Times to the first swallowing attempf ability to lift the head and standing were measured during recovery. The apnea was recorded in all animals but no significant difference was recorded between groups under study. Calculated doses of induction were sufficient for intubation of the animals. The average doses foe maintenance of anesthesia did not show any significant difference between groups under study. There were no significant differences found between groups in any comparable parameter. Despite of longer recovery time in group three, there were no significant differences between the Groups in different recovery times. Repeated propofol anesthesia did not improve resistance and respiratory changes in this species. However, some effects on blood pressure may happen without any effect on heart rate. © 2008 Asian Network for Scientific Information

Polymorphisms of the beta-1,4 galactosyltransferase-I gene in Holsteins

The scope of this study was to identify sequence polymorphisms in the β-1,4- galactosyltransferase-I gene (B4GALT1), the gene which encodes the catalytic part of lactose synthase enzyme. Exons of the gene were scanned for the presence of allelic variation among a sample of 400 Iranian Holsteins, using the single strand conformation polymorphism technique followed by sequencing. Nine polymorphic nucleotide sites and 16 different genotypes of B4GALT1 were identified. We concluded therefore that the β-1,4-galactosyltransferase-I gene was polymorphic in Holsteins. Considering the biological roles of the B4GALT1 gene, we suggest that further studies are critical to investigate the biological effects of the SNPs reported in this study