Evaluation of the diagnostic value of plasma copper levels in cattle

Copper (Cu) is an essential trace element. Depletion of liver-Cu stores leads to clinical or sub-clinical Cu deficiency. Our objective was to evaluate plasma-Cu levels as a diagnostic test for the assessment of Cu status in cattle. We used liver-Cu levels as the gold standard. The chosen cutoff for plasma Cu was 9 mmol/l; two different cutoffs were chosen for liver-Cu: 20 and 10 microg/g dry matter (DM). When 20 microg/g DM of liver Cu was the cutoff, plasma Cu had sensitivity=69% (58, 79) and specificity=84% (74, 93). The same values if the cutoff in liver was 10 microg/g were 92 (82, 100) and 73% (64, 82), respectively. ROC curves showed that the best cutoff to be used for plasma Cu was 8.26 mmol/l; however, no significant improvement was found in sensitivity or specificity. We concluded that interpretation of plasma-Cu levels significantly varies with the liver-Cu cutoff.     

Practical uses of ultrasound in early pregnancy in cattle

Using a 'real-time' ultrasound scanner with a 3.5 MHz rectal transducer, a herd of 80 Friesian cows were scanned at weekly intervals during early pregnancy to assess the accuracy of pregnancy diagnosis, and the accuracy of twin detection. The growing fetuses were also measured to determine the relationship between crown-rump length and age. The accuracy of detection of pregnancy was inversely proportional to the age of the cow (r -0.967), the accuracy of detection of twinning was 100 per cent and there was strong correlation between fetal crown-rump length and age (r 0.98).     

Evaluation of the DG29 test for early detection of pregnancy in cattle

The objective of this study was to evaluate a commercial blood test (DG29) for pregnancy in cattle. Compared with ultrasound, the sensitivity of the assay for detecting pregnancy around day 30 post-insemination was 99.4% [95% confidence interval (CI): 96.1–100]. The specificity was 100% (95% CI: 84.7–100) in noninseminated cattle, and 66.7%; (95% CI: 49.7–80.4) in inseminated nonpregnant cattle. Positive and negative predictive values were 92.6% and 96.3%, respectively, in a sample of inseminated cattle in which 80% were pregnant.     

Biogenic amine levels in acute Babesia bovis infected cattle

Plasma and whole blood from splenectomized calves infected with B. bovis were assayed by fluorimetric techniques for histamine, 5-hydroxytryptamine (5-HT), noradrenaline and dopamine levels. In addition PCV, thrombocyte and parasite counts were also undertaken. Plasma histamine levels rose till day 4 post-infection (p.i.) and were still elevated on day 7 p.i. Wholw blood histamine levels were significantly higher on days 1, 4 and 6 p.i. Plasma 5-HT levels rose to peak levels on day 3 p.i. and were still significantly elevated on day 7 p.i. Whole blood 5-HT levels were significantly higher on days 1 and 2 p.i. but fell to subnormal levels terminally. Dopamine and noradrenaline levels for both whole blood and plasma were unaltered during the disease process. Thrombocyte levels initially rose, reaching maximum values on day 3 p.i. The level fell continuously below normal from day 4 to 7 p.i. The PCV fell continuously from day 1 p.i. The experimental animals suffered a severe and fatal syndrome, all dying 7 days p.i.     

科尔沁肉牛早期补饲饲养模式试验研究

[目的]通过试验探究科尔沁肉牛犊牛最佳的饲养模式,为后续科尔沁肉牛早期补饲的推广和普及提供理论支持。[方法]选取体型相近,初生体重在34～50 kg之间健康的科尔沁肉牛犊牛60头,分为对照组、补饲组1、补饲组2,每组20头,补饲组按试验方案进行早期补饲,对照组按传统饲养模式饲养,对比6月龄各项数据及试验牛母牛产后发情情况,进行分析总结。[结果]补饲组与对照组相比,犊牛生长发育效果差异显著,试验母牛产后恢复明显加快,产后90 d内发情母牛占比显著提高。[结论]科尔沁肉牛犊牛早期补饲更利于犊牛后期生长发育,促进母牛早发情提高繁殖能力,结合数据分析得出早期补饲至6月龄是更为适合科尔沁肉牛犊牛的饲养模式。