The relationship between packed cell volume and the course of disease in milk fever in dairy cows

Results from a field investigation involving 1086 cows with clinical milk fever, revealed a clear relationship between PCV at the time of first treatment and the subsequent course of the disease. Average PCV was progressively higher as the cows required one, two, or more than two treatments before recovery, and was highest in cows which subsequently failed to recover. PCV in healthy, periparturient cows was considerably lower than in cows with milk fever. PCV was negatively correlated with plasma Ca, and varied, moreover, with the time of first treatment in relation to calving, and also with the length of time the cow had been recumbent before being treated for the first time. PCV was also measured during the further course of the disease in cows which received more than one treatment (2nd to 6th treatments).     

The relationship between udder health and milk production in SMR cows

Analyses made of seven dairy units revealed that clinically manifest udder inflammations had occurred once or repeatedly to 23.9 per cent of all cows in their first lactation and to 34.0 percent during the fourth lactation. Cows with no clinical udder inflammation in the first and second lactations were superior by 205 kg of milk to animals in whom such inflammations developed during the second lactation. Correlation coefficients between udder health and milk yield were between -0.22 and 0.32 and were likely to suggest that in the long run improvement of the genetic potential for milk yield was accompanied by deterioration of udder health. Therefore, udder health should be included by stabilising selection in Friesian dairy cattle breeding in the GDR. A sufficient breeding potential will be left for milk yield parameters, as was shown by simulated selection experiments.     

Relation between biochemical parameters in the blood of cows and milk production

No differences in blood samples were found out when the biochemical parameters in arterial and venous blood of dairy cows were compared before and after milking. Negative correlation coefficient (r = -0.3460) approaching the significance level was determined by comparing the values for milk yield on the day of sampling (in ascending phase of lactation) and protein content in venous blood after milking, and significant negative correlation coefficient (r = -0.3813) for daily milk yield and gamma-globulin concentration in venous blood before milking. The relationship between butterfat content on the day of milking and the values of alkaline phosphatase can be characterized by significant up to highly significant negative correlation coefficients in all three blood samples (r = -0.3232 to -0.3908).     

Concentrations of apolipoprotein C-III in healthy cows during the peripartum period and cows with milk fever.

Apolipoprotein (apo) C-III is a low-molecular-mass protein mainly distributed in the high-density lipoprotein fraction in cattle serum. We have recently shown that the apoC-III concentration is decreased in cows with fatty liver, ketosis, left displacement of the abomasum, retained placenta and milk fever. The decrease was most distinct in milk fever, thereby suggesting that apoC-III is particularly relevant to the development of milk fever and also that apoC-III is a candidate diagnostic marker for this disease. The purpose of the present study was to examine whether the apoC-III concentration in healthy cows is altered during the peripartum period, to assess the usefulness of apoC-III as a marker for milk fever. ApoC-III concentrations in 17 cows were monitored during the peripartum period (-48 to +12 days from parturition). Of the 17 cows, 14 were apparently healthy during the period. The apoC-III concentrations in the 14 healthy cows were unaltered during the period from -48 to -21 days, but thereafter showed individual variations. Compared with values during the period from -48 to -21 days, the apoC-III concentration was increased (137%) in 5 cows during the period from +1 to +12 days, whereas it decreased (60.7%) in 9 cows. Three cows suffered from milk fever at -3 to +10 days. Decreased apoC-III concentrations in diseased cows (15 to 37% of controls) were more distinct than in the 9 healthy cows. The apoC-III concentration was correlated with lecithin:cholesterol acyltransferase activity in cows with milk fever, but not in healthy cows. Correlation analysis also indicated that apoC-III and apoB-100 concentrations were negatively correlated in 5 healthy cows with increased apoC-III concentrations, but positively in 9 healthy cows with decreased concentrations and cows with milk fever. Determination of the apoC-III concentration during the peripartum period is suggested to be helpful in diagnosing milk fever. The possible relevance of apoC-III and apoB-100 in the development of milk fever is also implied.     

Relation between the biochemical composition of the blood of cows and variations in milk production

A significantly lower alkaline phosphatase activity was recorded in the arterial blood of cows with higher milk efficiency. They also had higher sugar contents in their blood: highly significantly in arterial blood and significantly in venous blood after milking. As to the other blood components, the differences are low and insignificant. A significant positive relationship between the daily milk yield and the content of ash in blood (mainly in venous blood before milking), highly significant positive relationship between protein content in arterial blood and daily milk yield, and significant to highly significant negative relationship between the activity of alkaline phosphatase in arterial and venous blood before milking and the level of gamma-globulins in arterial blood were recorded in the group of cows with higher milk output. In the group of cows with lower milk production, significant to highly significant negative relationships were obtained between protein content in blood and the daily milk yield (in arterial and venous blood before milking).     

The relationship between production and infertility in dairy cows

Extract

Each year increasing numbers of livestock are transported by land, rail, sea and air, vet documented observation of the behaviour of stock during transit has seldom been recorded. The trans-shipment of weaner calves between the North and South Islands of New Zealand provided an opportunity to gather information on conditions of travel and general adaptation to a journey of 1600 kilometres by road and air.     

Natural antibodies in bovine milk and blood plasma: variability among cows, repeatability within cows, and relation between milk and plasma titers

Innate immunity plays an important role in preventing (barrier function) or combating infection (effector function). An important humoral component of innate immunity is formed by natural antibodies (NAb). The objectives of this study were to determine presence, variation among cows and repeatability within cows over time of total NAb titers directed to the pathogen-associated molecular patterns lipopolysaccharide, lipoteichoic acid (LTA) and peptidoglycan, and titers of NAb directed to the glycoprotein keyhole limpet hemocyanin in milk and plasma of individual cows. Furthermore in milk the antibody isotypes IgG1, IgG2, IgM and IgA binding LTA were analyzed. Ten milk and blood samples were obtained from each of 20 clinically healthy dairy cows from first to seventh parity during a period of 3 weeks. Total NAb binding lipopolysaccharide, LTA, peptidoglycan, and keyhole limpet hemocyanin were detected in milk and plasma, with titers considerably higher in plasma than in milk. Total NAb titers showed significant variation among cows, and repeatability within cows over time (ranging from 0.60 to 0.93). Titers of NAb in milk and plasma were positively correlated (correlation ranging from 0.69 to 0.91). Natural antibodies in milk binding LTA were of all 4 isotypes tested, although IgG2 was on average only present at low titers. All 4 isotypes in milk binding LTA also showed variation among cows, and repeatability within cows over time (ranging from 0.84 to 0.92). We conclude that NAb can be measured in a consistent and repeatable manner in bovine milk and blood plasma.     

Relation between biochemical components in the blood of cows of various strains and the daily milk yield

During the evaluation of the biochemical components of the arterial and venous blood of cows before and after milking, an insignificantly higher content of ash was found in the blood of the cows of Black-Pied Lowland breed, as compared with the Slovak Pied breed. The difference in the activity of alkaline phosphatase was found to be significant: the higher alkaline phosphatase activity was recorded in the blood of the cows of Slovak Pied breed than in the cows of Black-Pied Lowland cattle of the same age and in the same stage of lactation. A positive relationship was found between the milk yield and albumin level in the blood of the dairy cows of Black-Pied Lowland cattle; in the same breed a negative relationship was found between venous blood before milking and the level of gamma-globulins.     

The effect of free amino acid levels in the blood and milk of cows on protein levels in milk

In the cows of the whole group under study, a significant negative relation (r = = -0.4797) was found between the histidine level in arterial blood and protein content in milk; further, there was a significant positive relation (r = 0.4624) between alanine level in milk and protein content in milk, and a significant negative relation (r = -0.5028) for the level of threonine. The group of cows with a higher milk output showed a significant negative relation between methionine level in milk and protein content in milk (r = -0.7482) and a highly significant negative relation between threonine level and protein content in milk (r = -0.8410). The negative relations of some amino acids to the content of protein in milk suggest that there is a poor supply of these amino acids for the production of protein in milk.     

泌乳初期奶牛乳成分与血液生化指标相关性研究

通过分析泌乳初期健康、酮病和低钙血症奶牛血液生化指标及乳成分,明确相关疾病的乳成分特征,同时对泌乳初期奶牛血液生化指标与乳成分相关性进行分析,以期为牛群健康评价提供方法支持。根据血液指标选取产后7~21d荷斯坦奶牛72头,分为亚临床低钙血症试验组、酮病试验组和健康对照组,每组各24头。采集试验奶牛的血液和乳汁用于血液生化指标与乳成分相关性分析。结果显示,酮病和低钙血症引起乳蛋白和非脂乳固体水平降低,而乳中柠檬酸的含量增加。奶牛乳中柠檬酸与血清NEFA、BHBA和GLU相关性方程分别为:y=3.192x-0.802,R~2=0.363;y=4.594x-0.793,R~2=0.320;y=1.228x+0.775,R~2=0.261;其中方程中x为乳中柠檬酸的含量。结果表明,乳中柠檬酸的含量与血液NEFA呈显著正相关,可用于能量负平衡的早期诊断标示物。血中BUN及ALB的水平可用于评价乳蛋白和尿素的水平。     

Characterization of the serum metabolic profile of dairy cows with milk fever using 1H-NMR spectroscopy

Background: Milk fever (MF) is a common calcium metabolism disorder in perinatal cows. Currently, information regarding the detailed metabolism in cows suffering from MF is scant.

Objective: The purpose was to study the metabolic profiling of serum samples from cows with MF in comparison to control cows, and thereby exploring other underlying pathological mechanisms of this disease.

Animals and methods: In the current study, we compared the serum metabolomic profile of dairy cows with MF (n = 8) to that of healthy dairy cows (n = 24) using a 500-MHz digital ¹H-nuclear magnetic resonance (¹H-NMR) spectrometer. Based on their clinical presentation and serum calcium concentration, cows were assigned either to the control group (no MF symptoms and serum calcium concentration >2.5 mmol/L) or to the MF group (MF symptoms and serum calcium concentration <1.4 mmol/L). For statistical analysis, a one-way analysis of variance was performed.

Results: We identified differences regarding nine metabolites between the two groups, among which glucose, alanine, glycerol, phosphocreatine, and gamma-aminobutyrate decreased, and β-hydroxybutyrate, acetone, pyruvate, and lysine increased in cows with MF. Most of these were carbohydrates and amino acids involved in various energy metabolism pathways.

Conclusion: The different metabolites in cows with MF reflected the pathological features of negative energy balance and fat mobilization, suggesting that MF is associated with altered energy metabolism.

Clinical importance: The ¹H-NMR spectroscopy can be used to understand the pathogenesis of MF and identify biomarkers of the disease.     

血清微量元素与奶牛乳房炎发病关系的试验

生物体内的微量元素、维生素在清除自由基的过程中发挥着重要的生理功能,微量元素铜(Cu)、锌(Zn)、硒(Se),锰(Mn)、铁(Fe)是某些抗氧化物酶的主要构成成分,发挥抗氧化作用;维生素A、维生素C、维生素E具有抗氧化作用,是生物体内良好的自由基清除剂[1].     

Management of dry cows for the prevention of milk fever and other mineral disorders.

Mineral disorders in dairy cattle typically occur soon after calving and are often specifically related to nutritional management during the late dry period. The incidence of hypocalcemia, hypophosphatemia, and hypomagnesemia can be minimized by proper diet formulation and good overall nutritional management in the dry period. The addition of anions to the diet during the late dry period may be of particular benefit for preventing hypocalcemia; however, supplementation with anions will reduce dry matter intake if feeding management is not excellent.     

The relationship between changes in serum glycine and alanine concentrations in non-essential amino acid and milk production in the transition period in dairy cows

The serum concentration of non-essential amino acid (NEAA) was measured in ten Holstein dairy cows grouped as low production (n=5) and high production (n=5) from one month pre-partum through four months post-partum and the relationship between production and amino acid concentrations was studied. The glycine (Gly)/NEAA ratio and the glycine/alanine ratio of the high production group were significantly higher than the low production group (p<0.01). The observed decrease of the alanine (Ala)/NEAA ratio was more remarkable in the high production group than in the low production group. Measurement of Gly/Ala ratio in serum may be useful for evaluating the nutritional status of peri-parturient dairy cow.     

荷斯坦奶牛体型线性评定及其性状与产奶量的相关性分析

采用9分制线性评定法对湖北宜昌地区饲养的荷斯坦奶牛进行体型线性评定，9分制奶牛体型外貌评定系统分为5大块，即结构／容量、尻部、肢蹄、泌乳系统和乳用特征，共24个性状，对每一性状给予1．9分的评分，最终根据此评分，选育高产、健康、优秀、长寿的优质牛群以获得最好的经济效益。     

Pharmacokinetics and penetration of danofloxacin from the blood into the milk of cows

The single-dose disposition kinetics of danofloxacin were determined in clinically normal lactating cows after intravenous (i.v.) and intramuscular (i.m.) administration of the drug at 1.25 mg/kg. The drug concentrations in blood serum and milk were determined by microbiological assay methods and the data were subjected to kinetic analysis. The mean i.v. and i.m. elimination half-lives ( t _½el) in serum were 54.9 and 135.7 min, respectively. The steady-state volume of distribution ( V _ss) was 2.04 L/kg. The drug was quickly absorbed after i.m. injection but a 'flip flop' effect was clearly evident and bioavailability was > 100%. Penetration of danofloxacin from blood into milk was rapid and extensive with drug concentrations in milk exceeding those in serum beginning 90–120 min after i.v. and i.m. administration and onwards. Milk danofloxacin concentrations equal to or higher than the minimal inhibitory concentrations (MIC) for pathogenic Gram-negative bacteria and Mycoplasma species were maintained over ≈ 24 h.
  Concentrations greater than the MIC for Staphylococcus aureus were maintained in the milk for 12 h.     

The relationship between leptin gene polymorphisms and reproductive traits in Jersey cows

The aim of the study was to analyse the relationship between three leptin gene polymorphisms, and indices of reproductive performance--age at first calving, days open, calving interval, number of inseminations per conception, and gestation length in Jersey cattle. A total of 219 cows were tested for the R4C, A59V and C(-963)T mutations using the PCR-RFLP technique. The following allele frequencies were found: R4C--0.80 (C) and 0.20 (T), A59V--0.67 (C) and 0.33 (T), C(-963)T--0.83 (C) and 0.17 (T). The statistically significant correlation (P < or = 0.05) was found only for the A59V mutation. Cows with the TT genotype were characterized by shorter calving interval and time of days open than animals with CT and CC genotype. Also, the number of inseminations per conception was lower in A59V--TT homozygotes compared with two other genotypes. The association analysis did not reveal any significant correlations for both R4C and C(-963)T polymorphisms.     

The effect of salinomycin on certain blood parameters and milk quality of lactating sows

Twenty-five gilts and sows, after pregnancy confirmation using the ultrasonic method, were randomly divided and allocated to the following five experimental groups: SAL0 = negative controls, SAL20 = 20 mg salinomycin per kg of feed, SAL40 = 40 mg salinomycin per kg of feed, SAL60 = 60 mg salinomycin per kg of feed and SAL80 = 80 mg salinomycin per kg of feed. All animals remained under treatment for two consecutive breeding cycles. The sows were fed a home-mixed balanced feed during gestations and lactations. At the third, tenth and eighteenth day of each lactation, blood and milk samples were collected. Blood samples were analysed for cholesterol and total lipids and milk samples were analysed for the determination of the fat, lactose, protein, ash and totals solids concentrations. In all treated groups, cholesterol concentrations were significantly higher (P < 0.05) compared with the controls. Total lipid concentrations were significantly higher (P < 0.05) in SAL40 and SAL60 groups in comparison with SAL0 and SAL20 groups, during both cycles. Milk fat concentrations were higher (P < 0.05) in treated groups than in the control group; the highest concentrations were observed at SAL40 and SAL60 groups. In all treated groups, concentrations of milk lactose were significantly higher (P < 0.05) than those observed in the negative control group. Milk protein concentrations were significantly higher (P < 0.05) in SAL40 and SAL60 groups compared with the SAL0 group, but there was no significant difference in SAL20 and SAL80 groups in comparison with the SAL0 group. No significant differences were observed concerning milk ash concentrations between all groups. In all treated groups, concentrations of total solids were significantly higher (P < 0.05) in comparison with the control group; the highest concentrations were observed in the SAL40 and SAL60 groups. It is concluded that the use of salinomycin in sow diet, increases concentrations of blood triglycerides and cholesterol and improves the quality of milk, thus reflecting on higher weight gain and survival rate of suckling piglets.