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Biomedical subjects

B Pehrson

Publications and source records attributed to B Pehrson.

At least 19 recordsLinked to original sources
PubMed1992

The effect of additional feeding on the fertility of high-yielding dairy cows.

One hundred and ninety three pairs of cows were selected from 38 herds, and the numbers of each pair were assigned at random to experimental and control groups. Each control cow was fed according to its yield with the feedstuffs normally used by the herd. Each experimental cow was fed in the same way and, in addition, received 500 g of a feed additive twice daily from the 40th day of lactation until first insemination or to the 75th day of lactation if no visible oestrus had been observed between days 40 and 75. One kg of the feed additive contained glucogenic substances (glycerol and Ca-propionate) equivalent to 1.90 moles of glucose, 13.6 MJ metabolizable energy, and 180 g digestible crude protein. There were no significant differences between the groups with respect to their mean daily milk yield, their plasma glucose concentrations at first insemination, or the interval between calving and first insemination. However, the experimental cows had a significantly shorter interval between calving and last insemination (mean difference 11.0 days). The pregnancy rate was significantly higher among cows with high than among cows with low plasma glucose concentrations. There was also a tendency towards a reduced pregnancy rate among cows with either high (greater than 7.0 mmol/litre) or low (less than 4.0 mmol/litre) milk urea concentrations.

Animal Feed↗
PubMed1991

The relationships between the fertility of dairy cows and clinical and biochemical measurements, with special reference to plasma glucose and milk acetone.

Blood and milk samples were taken at first insemination in 352 dairy cows from 18 herds for charting the relation between clinico-chemical parameters and fertility rate. Neither total protein, albumin, globulin, AST, bilirubin, bile acids, calcium, magnesium and phosphorus in blood nor urea in milk was significantly related to the rate of pregnancy. On the other hand, there was a significant difference for plasma glucose between cows that became pregnant and those that did not. Cows with low plasma glucose concentrations at first insemination also had low values four and seven weeks after calving, indicating that it is primarily cows with chronically low blood glucose which are likely to have reduced fertility. At first insemination there was no increase in the concentration of acetone in milk of cows with reduced fertility. However, they had had increased milk acetone concentrations three to five weeks after calving. It therefore seems possible to evaluate the risk of reduced fertility by measuring either blood glucose or milk acetone some weeks after calving. Owing to the difficulties associated with the sampling and laboratory techniques for glucose, analyses of milk acetone are more suitable under field conditions.

Acetone↗
PubMed1991

Effect of vitamin E supplementation on weight gain, immune competence, and disease incidence in barley-fed beef cattle.

The aim of the study was to investigate whether vitamin E supplements in larger amounts than recommended could reduce incidence of disease, improve immune competence, and increase rate of weight gain of conventionally barley-fed beef cattle. Mean daily intake of vitamin E by individual calves in the experimental group was 200 mg during the first 2 mo, 400 mg during the next 2 mo, and 600 mg during the rest of the period. Corresponding daily intakes of vitamin E for the control group were 50, 100, and 150 mg. Mean plasma vitamin E of the experimental group increased from .49 mg/L at the start of the trial to 2.03 mg/L at the end, but that of the control group was lower at the end (.36 mg/L) than at the beginning (.53 mg/L). No significant differences were observed between the groups concerning incidence of disease or magnitude of lymphocyte stimulation. The results indicated that there was a surprisingly poor biological availability of the dietary vitamin. Therefore, a comparison in reality was made between calves with inadequate and normal vitamin E status. The differences in daily BW gain and time to reach slaughter weight thus probably were effects of the low vitamin E status rather than positive effects of additional vitamin in the diet.

Animals↗
PubMed1990

Vitamin E status in newborn lambs with special reference to the effect of dl-alpha-tocopheryl acetate supplementation in late gestation.

Pregnant ewes were supplemented with dl-alpha-tocopheryl acetate, either as a single intramuscular dose (500 mg two weeks before lambing) or perorally (150 mg daily during 3-4 weeks before lambing). Ewes without such a supplementation were controls. The vitamin E supplemented ewes had nearly twice as high vitamin E (alpha-tocopherol) concentrations as the unsupplemented control ewes at lambing both in serum and in colostrum. The vitamin E concentration in colostrum was 5-11 higher than in milk 1 week after lambing. Both supplementations somewhat increased the vitamin E serum concentration of the newborn lambs, but the increase was negligible in comparison with the effect produced by the consumption of colostrum. All lambs had very low serum concentrations at birth. The lambs from the supplemented ewes had significantly higher serum values than the control lambs 24 h after birth. The ewes had somewhat higher selenium status at birth than their offsprings when evaluated by glutathione peroxidase (GSH-Px) in the erythrocytes. It seems reasonable that nutritional muscular degeneration may arise in newborn lambs with a normal selenium status if their vitamin E status is critical, either because of an inadequate consumption of colostrum or because of a vitamin E deficient diet during pregnancy with a low vitamin concentration of colostrum as a consequence.

Administration, Oral↗
PubMed1975

[Low milk fat syndrome in dairy cows. Field trial with potential fat content increasing substances (author's transl)].

In cases of low milk fat syndrome in dairy cows, in which no cause-factor could be found, a mixture of different potential fat content increasing substances was added to the feed, one group was fed 50 g NaHCO-3, 50 g MgO, 50 g urea and 100 g sodium bentonite mixed into 250 g of carrier per cow per day, while another group was fed the same mixture with sodium bentonite excluded. A third group was used as an untreated control. Fat content and milk yield were not positively influenced by these additives. The inclusion of sodium bentonite even seemed to result in a certain decrease of milk yield. In another similar trial, 150 g NaHCO-3 and 100 g MgO were fed, mixed into 250 g of carrier per cow per day. This improved the milk fat content when compared to an untreated control group. The increase was not significant. The milk yield, however, was significantly influenced by the addition. The yield increase in this trial was calculated to be approx. 2.0 kilos FCM per cow per day.

Animal Feed↗
PubMed1975

The effect of different calcium doses in milk fever therapy. A comparative internordic field study.

In an internordic field study of the effect of the Ca dose (6, 9 and 12 g) on the therapeutic result in parturient paresis, considerably better results were recorded in Finland than in the other countries at all dose levels. In Finland a full effect was obtained with 6 g, while in all others 9 g Ca yielded a significantly better result than 6 g. Raising of the dose to 12 g produced no improvement. There was a significant difference in therapeutic results between the two Finnish breeds. A larger number of fatal cases was recorded among paretic cows with plasma Ca greater then 8.0 mg/100 ml.

Animals↗