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Relations between the concentration of glucose and urea in blood plasma and the qualitative ejaculate parameters were investigated in 24 breeding bulls (13 Holstein and 11 Czech Spotted) over a 12-month period. The average concentrations of plasma glucose and urea were 3.32 mmol ∙ 1⁻¹ and 3.57 mmol ∙ 1⁻¹ , respectively. No statistically significant differences in the concentrations of glucose and urea (i.e. 3.34 vs. 3.30 mmol ∙ 1⁻¹ and 3.53 vs. 3.61 mmol ∙ 1⁻¹, respectively) were observed between the Holstein bulls and Czech Spotted bulls. A statistically significant (P ≤ 0.05) positive correlation was found between the concentration of plasma urea and the ejaculate volume for the whole investigation period (rp = 0.19). Similarly, the correlation between the concentration of plasma urea and sperm motility was positive (rp = 0.11), whereas the increase in plasma urea concentration negatively influenced sperm concentration ( rp = -0.10). Correlations between plasma glucose concentrations and the respective parameters of ejaculate quality were similar in magnitude, i.e. ejaculate volume ( rp = 0.12), sperm motility ( rp = 0.12) and sperm concentration ( rp = -0.08). During the investigations the coefficients of correlation between plasma glucose and urea concentrations as well as qualitative parameters of the ejaculate were found to be negative in months when concentrations of glucose and urea in the blood plasma of the bulls markedly changed.
Blood samples were taken from 134 Holstein cows between day 20 to 100 postpartum to determine the concentration of urea, cholesterol, glucose and total lipids and to define their relation to the reproductive performance traits: interval (I), service period (SP) and insemination index (II). Investigations were carried out in monthly intervals from October 1996 to October 1997. Average values of plasma urea, total lipids, cholesterol and glucose for the entire period studied were 5.78 mmol.1⁻¹, 3.61 g.l⁻¹, 3.34 mmol. l⁻¹ and 3.61 mmol. l⁻¹, respectively. High concentration of blood urea was related negatively with the value of the insemination index (rp = -0.51). When the average concentrations of total lipids were low in plasma in the specified time (month) negative correlations were found between total lipids and the length of service period (rp = from -0.23 to -0.54) and value of the insemination index (rp = -0.42). The concentration of plasma total lipids increased in time from post partum. Traits of reproductive performance were affected by the internal environment. Especially negative influences were observed when the concentration of plasma urea as well as total lipids and cholesterol increased or decreased abnormally.
Groups of 19 to 24 dairy Holstein cows were observed monthly for the period of 12 months (12 test days). The aim of the study was to observe the relationship between blood plasma cholesterol concentration and milk production and milk components. The mean milk yield was 33.8 kg with milk protein content 2.96%, milk fat content 4.02% and cholesterol concentration in blood plasma 3.44 mmol/1. Cows in the experimental groups were in their early lactation (on average 58.6 days after calving). The coefficients of the correlation between blood plasma cholesterol and some milk production parameters calculated for each test day ranged as follows: - 0.361 to 0.437 for milk yield, -0.275 to 0.203 for milk fat content and -0.181 to 0.480 for milk protein content. Polynomials of the third degree or higher were calculated for the observed parameters so as R~ was higher than 0.5. The calculated coefficients of correlation between blood plasma cholesterol content and milk production parameters did not reveal a clear tendency in the relationships. However, the graphical polynomial expression of relationships showed a positive relationship between blood plasma cholesterol content and milk yield and a negative relationship between blood plasma cholesterol and milk protein content. No relationship was found between blood plasma cholesterol concentration and milk fat content due to high variability of fat content in milk.
The blood from 23 breeding boars was taken to analyse of minerals in the blood plasma 4 times in the course of 5months. The mean Ca, P, Mg and Cu concentrations were 2.24mmol l⁻¹, 1.95mmol l⁻¹, 0.71 mmol l⁻¹ and 34.49 μmol l⁻¹, respectively; the Ca : P ratio was 1.18. During the entire experimental period the average sperm concentration, ejaculate volume and sperm motility of all the boars was 0.43 · 106 mm-3, 303.20 cm3 and 89.00%, respectively. The average total number of sperm (TNS) and the total number of motile sperm (TNMS) in the ejaculate was 130.49 · 109 and 116.12 · 109, respectively. A statistically highly significant negative correlation (P < 0.01) were detected between the concentration of P in the blood plasma and the ejaculate volume (rp = -0.40), TNS (rp = -0.34) and TNMS (rp = -0.33). There was significant positive correlation between the Ca:P ratio and the ejaculate volume rp = 0.28 (P < 0.01), TNS rp = 0.22 (P < 0.05) and TNMS rp = 0.22 and rp = 0.21 P < 0.05). The mean concentrations of Ca, P, Mg and Cu in the boar seminal plasma were 0.38 mmol l⁻¹, 1.22 mmol l⁻¹, 3.03 mmol l⁻¹ and 9.51 μmol l⁻¹, respectively; the Ca:P ratio was 0.34. The mostly negative correlations were detected between the sperm parameters and concentrations of Mg in the semen plasma – from rp= -0.52 (P < 0.05) to rp= 0.12. There is possible, to state that concentration of monitored minerals in blood and seminal plasma influence qualitative sperm parameters. Optimizing of their concentration and proportional ratio could lead to positive influencing of sperm qualitative parameters.
Czech Pied dairy cows were observed one day each month for the period of 12 months (12 test days). All the cows were in the first phase of lactation, i.e. up to 100 days after calving. The mean number of lactation was 2.8, the cows were on average 54.8 days after calving and the mean concentration of cholesterol in blood plasma was 3.93 mmolˇdm-3 (149.4 mgˇ10-1dm-3). During the first 100 days of lactation milk yield amounted to 2 581 kg with 3.91% fat, 3.48% protein and 4.85% lactose. Despite high values of correlation obtained within single test day, relations for the entire year between blood plasma cholesterol concentration and milk production parameters did not reveal strong relationships (from –0.013 to +0.259). However, the graphic polynomial expression showed that cholesterol concentration tended to have negative relationship with milk fat or milk lactose content.
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