Effects of oral administration of monensin on serum glucose, AST, and arginase of holstein cows during transition period

In the present study, under typical management conditions of dairy farms in Iran, the effect of oral administration of on serum glucose, AST and arginase[indices of liver injuries] of oral monensin was assessed. Thirteen multiparous Holstein cows were blocked into a control and an experiment group from 3 weeks prepartum to 45 days postpartum according the number of their calvings. The groups received similar diets. The experiment group received monensin added to grain mix at 340 mg/head/day during prepartum weeks, 160-480 mg/head/day during first two weeks postpartum, and 350 mg/head/day during days 15-45 postpartum. Blood samples were obtained at days -20 and -10 prepartum, and days 4, 15, 25, 35 and 45 postpartum to determine serum glucose, AST, and arginase. Serum glucose decreased significantly [p = 0.025] in the control group from day 10 prepartum to day 15 postpartum. In the experiment group it increased significantly [p = 0.049] from the beginning of the experiment to day 35 postpartum. On day 15 postpartum, serum glucose showed a tendency [p = 0.07] for significant difference between groups. The level of ASTwas higher in the experiment group from day 10 prepartum to day 25 postpartum with a significant difference [p = 0.011] on day 10 prepartum. There was no significant difference in serum arginase activity between control and experiment groups [p > 0.05]. Administration of monensin mixed with diet can result in better functions of the liver, increase [or prevention of decrease] in serum glucose during peripartum weeks. It appears that changes in the dose of the drug during the early postpartum days [due to changes in dry matter intake] cannot affect the positive effect of monensin. The positive effect of monensin can be started prepartum; thus, its administration from prepartum transition period continued to postpartum weeks is recommended

Effects of oral administration of monensin on milk yield, milk economic components and iodine value of milk fat in holstein-friesian cows in early lactation

Assessing the effects of monensin on economic factors of milk [percents of protein and fat], and quality of milk fat during early lactation. Thirteen multiparous Holstein cows were blocked into a control and a treatment group from 3 weeks prepartum to 45 days postpartum according the number of their calving. The groups received similar diets. The treatment group received monensin added to grain mix at 340 mg/head/day during prepartum weeks, 160-480 mg/head/day during first two weeks postpartum and 350 mg/head/day during days 15-35 postpartum. Milk samples were obtained on days 15, 25, 35 and 45 postpartum. Milk volume during a standard period of 305 days and during the first 3 months of lactation, percentages milk protein and milk fat and iodine value of milk fat were determined. Data were studied with the SPSS statistical software using analysis of variance for repeated measures and independent t test. No significant differences were observed between control and experiment groups in volumes of milk during the first 3 months of lactation and the standard production of the entire lactation period. The natural decrease in the percentage of milk protein and fat postpartum was observed in both groups. However, the pattern of decrease in milk protein was slower in the treatment group. There was no difference between the groups in milk protein at various stages of sampling. Milk fat increased in the treatment group from day 25 of lactation and on day 45, it was significantly higher in the treatment group than in the control cows. The iodine index of milk fat was nonsignificantly higher in the treatment group throughout of the experiment. The present study showed that administration of monensin during periparturient weeks has no adverse effect on milk volume, percentage of milk protein and fat and the quality of milk fat. It may lessen the decreasing pattern of milk protein and fat, or accelerate the time for their increasing. Increased level of unsaturated fatty acids in milk is a positive point in feeding monensin

Changes of milk fat, crude protein, NPN and protein: fat ratio in holstein cows fed a high concentrate diet from early to late lactation

Percentages and yields of fat, crude protein [CP], true protein [TP] and non-protein nitrogen [NPN] were assessed in milk of four groups of Holstein cows, at early, mid and late lactation [days in milk 20-70, 71-110. 111-150 and 151-210], on a diet rich in concentrates during a hot summer. Four milk samples were taken from individual cows at 10-day intervals. Milk fat percentages were close to breed average and increased toward the end of lactation with a tendency [P = 0.055] for significant difference between the early and late lactation. Percentages of CP [P = 0.14] and TP [P = 0.478], however, were low similarly among all groups and did not follow the normal pattern of the breed. Percentage of NPN was significantly higher in groups Ill and IV [P = 0.005]. Yields of fat [P = 0.035], CP [P = 0.002] and TP [P = 0.001], but not NPN [P = 0.589], decreased toward the end of lactation. There was a negative correlation [r = -0.354, P<0.001] between the percentages of NPN and TP. However, no correlation was observed between the percentages of NPN and CP. Despite a very strong correlation between yields of CP and TP [r = 0.983, P<0.001], the correlation between the yield of CP and that of NPN was much weaker [r = 0.473, P<0.001]. It is concluded that percents and yields of milk fat, close to breed average are attainable at any stage of lactation on high concentrate diets in hot weather. However, regarding milk protein, cows may not perform well. TP may be more affected than CP

Changes in and correlations between some serum constituents and milk components from early to late lactation in a dairy herd with subclinical production disorders

Changes in some serum constituents and milk components and correlations between them, were used for defining the reason [s] of suboptimal milk composition in a dairy herd with a history of low protein tests during summers. Four groups of 8 adult Holsteins, 20-70, 70-110, 110-150 and 150-210 days in milk [DIM], under heat stress, with similar feeding and management practices were sampled for blood and milk four times on a 10 day interval. Milk volume, percentages of milk fat and protein and levels of serum glucose, total protein, albumin and BUN were determined. Milk volume decreased as DIM increased [P<0.05]. Milk fat showed normal changes, but milk protein was similarly low in all groups [P>0.05], showing probable shortages in energy and/or protein intake. Serum parameters showed no significant differences among groups [P>0.05]. Weak positive correlations were found between serum total protein and milk components after 150 DIM [maximum correlation with milk fat, r = 0.61]. It is concluded that shortage in intake of energy and/or protein, which may result in lowered milk protein, may not be differentiated by measuring serum glucose, total protein, albumin and BUN and milk components. More detailed experiments on serum and milk are necessary for defining the problem properly

[Quantitative and qualitative study of calf starters in some dairy farms around shiraz and Marvdasht]

In this research, the energy, crude protein, crude fat, crude fiber, calcium, phosphorous and salt of ten calf starters from ten dairy farms near Shiraz and Marvdasht were determind. The results were as follows: energy, crude protein, crude fat. crude fiber, calcium., phosphorous and salt contents were within the optimum range for 5, 1, 8, 6, 5, 6 and 3 dairy farms respectively. This survey showed that neither of the starters were optimum in relation to their chemical composition and in some cases in main ingredients. Nutritional problems can be one of the factors which retard the calf growth, increase the age at first service, and predispose the animal to diseases