In vitro phagocytic activity of milk neutrophils during lactation cycle in Murrah buffaloes of different parity

Milk samples were collected from 34 lactating Murrah buffaloes on days 0, 5, 15, 30, 45, 60, 90, 120, 150, 180, 210, 240, 270 and day 300 after calving. Milk somatic cell counts (SCC) were highest in multiparous buffaloes . Milk SCC were significantly lower in buffaloes of third and fourth parity during early lactation and than increased significantly (p < 0.01) by the end of lactation. Milk neutrophils were significantly lower in all the buffaloes during early lactation, but increased significantly (p < 0.01) afterwards. Milk lymphocytes were significantly higher during early lactation, but decreased significantly (p < 0.01) by the end of lactation. Phagocytic activity (PA) was highest in day 1 colostrum and then decreased significantly (p < 0.01) by the fourth milking in buffaloes of second, third and fourth parity . Phagocytic index (PI) was also highest in colostrums of primiparous buffaloes. Irrespective of parity, maximum PA and PI was observed during mid lactation. In terms of in vitro phagocytic activity, early lactation is the most critical period followed by late and mid lactation.     

Comparison of variance components for test-day electrical conductivity of milk and test-day somatic cell score for first lactation cows in an experimental herd

In recent decades, electrical conductivity (EC) has been introduced as an indicator of mastitis, and genetic selection based on this trait may be possible. In this study, genetic parameters for test-day EC and test-day somatic cell score (SCS) were compared. Data were collected from a Danish experimental herd, including daily records of EC and SCS from 265 first lactation cows. Different genetic models were tested, and a random regression animal model with a 4th order Legendre polynomial for the permanent environmental effect for both traits, a 1st order Legendre polynomial for the additive genetic effect of EC and a 2nd order Legendre polynomial for the additive genetic effect of SCS, gave the best fit. The patterns of the curves were similar for both permanent environmental and additive genetic variance for the two traits. Heritability estimates ranged from 0.05 to 0.12, and from 0.01 to 0.09, for EC and SCS, respectively. The estimate of genetic correlation between the traits was high, and ranged from 0.86 to 0.98. Based on these results, EC could be a potential indicator trait in a breeding programme where selection for increased mastitis resistance is included.     

Reliability in somatic cell count measurement of clinical mastitis milk using DeLaval cell counter

Somatic cell counts (SCC) measurements are typically performed using quantitative methods, such as the Breed method (Breed) and the Fossomatic method (FSCC). The DeLaval cell counter (DCC) developed recently is a quantitative somatic cell counter with a low initial cost and superior portability. However, since the DCC was specifically developed for measuring SCC of ≤ 4 × 10⁶ cells/mL milk from bulk tanks or individual cows, its reliability for estimating SCC that exceed this concentration has not yet been clarified. This study therefore examined whether it is possible to accurately measure SCC by diluting milk samples with initial SCC of 4 × 10⁶ cells/mL, as seen in clinical mastitis milk. We collected milk samples from 99 quarters of 99 Holstein cows with clinical mastitis. These milk samples were diluted 10‐fold with saline and thoroughly mixed before performing SCC measurement with the DCC. The correlation coefficients of SCC measured by the FSCC, Breed and DCC methods indicated strong correlations between each pair of methods. The findings showed that DCC can be used to identify bovine clinical mastitis milk and is useful as a quantitative SCC measurement device on farm sites.     

影响水牛体细胞克隆胚胎移植的因素

从不同发情方式、不同胚胎类型、不同胚龄以及不同季节来探讨影响水牛体细胞克隆胚胎移植的效率。结果显示,自然发情与同期发情方法对水牛体细胞克隆胚胎的移植受胎率有显著影响。鲜胚和冻胚移植后受胎率没有显著差异,其受胎率分别是9.79%、14.5%。在移植中,不论是鲜胚还是冻胚,6日龄胚胎移植受胎率最高。而且不同日龄(5、6、7、8～10d)克隆胚胎移植受胎率差异不显著(鲜胚P=0.260 7,冻胚P=0。065 2)。克隆胚胎在秋季移植时受胎率最高,受胎率是16.06%,比其他季节高,且差异显著(P<00.05).其次是春季,但夏季和冬季克隆胚胎移植后受胎率差异不显著(P>0.05)。结果表明,水牛体细胞克隆胚胎在胚胎移植中是可行的,但效率比较低。     

Relationships between milk characteristics and somatic cell score in milk from primiparous browsing goats

To determine milk yield and composition, total microbic count (TMC) and somatic cell count (SCC) of browsing goats throughout the first lactation, 100 goats of Sarda breed, equally distributed in four flocks (F1, F2, F3 and F4), were selected. They were exclusively fed pasture and hand‐milked once daily. Individual milk samples and daily milk yield were taken from each goat at monthly intervals, from March to July. Milk samples were analyzed for: total protein, fat, lactose, urea, freezing point (FP), pH, TMC and SCC. The data was subjected to analysis of variance and to correlation matrix. On the whole, in all the flocks, milk yield showed the highest production in April and May. Fat content increased (P < 0.01) throughout the lactation. Protein content showed the lowest value (P < 0.01) in June (4.15%). Urea and pH values were fluctuating. FP was lower (P < 0.01) at the start of lactation (?0.562 Hortvet degrees). TMC log10 values were low, considering the hand milking and inadequacy of facilities on the farms. SCC increased (P < 0.01) throughout the lactation and, on the whole, SCC and TMC were not correlated.     

Efficacy of two antibiotic treatments in curing clinical and subclinical mastitis in lactating dairy cows

Aim. To compare the bacteriological and clinical cure rates for clinical and subclinical mastitis in New Zealand dairy cows following treatment with either an intramammary penicillin-dihydrosptreptomycin preparation or a subcutaneous injection of penethamate hydriodide.

Methods. Milk samples were collected from clinical and subclinical cases of mastitis before and 14 and 21 days after initiation of treatment for bacteriological culture, somatic cell count determination and conductivity testing.

Results. No significant differences in the bacteriological cure rate of major Gram-positive pathogens, clinical cure rate, somatic cell count or conductivity were found between treatments. However, the bacteriological cure ralte of coagulase-negative staphylococcus infections and the overall bacteriological cure rate was lower for quarters treated with penethamate than with penicillin-dihydrosptreptomycin.

Conclusions. The bacteriological cure rate of mastitis caused by major Gram-positive pathogens, the clinical cure rate, somatic cell count and conductivity did not differ between the two antibiotic treatments.     

Effect of oral administration of colostrum on inflammation in the udders of dairy cows suffering from mastitis

The present study was undertaken to examine whether oral administration of colostrum to mastitic cows reduced inflammation in the udder. Fifty milliliters of a colostrum whey product was administered orally daily for 3 days to cows suffering from mastitis. Milk was collected on day 0 and 7 of colostrum administration. For Experiment 1, milk from 11 udder quarters with high somatic cell counts (SCC) in four cows was used. SCC in milk decreased significantly after colostrum administration, whereas colostrum administration increased sodium and IgA concentrations significantly compared with those before administration. In Experiment 2, cows with clinical mastitis were divided into two groups, with and without colostrum administration, whereas all cows with subclinical mastitis were administered colostrum. Antibiotics were infused into the mammary gland from the first day of colostrum administration for 2–4 days. There was no significant decrease in SCC after colostrum administration in any group. However, udder firmness in both clinical mastitis groups was reduced after administration regardless of colostrum administration. IgA concentration in both clinical mastitis groups was significantly increased after colostrum administration compared to that before administration, although there was no significant difference between them. These results suggest the possibility that oral administration of colostrum attenuates inflammation of the mammary gland. Further studies are required to examine the effect of colostrum more precisely using cows with subclinical and chronic mastitis and longer duration of colostrum administration.     

Housing of Norwegian goat herds and associations with milk yield and milk quality

Abstract

Data from a questionnaire regarding housing factors were merged with data from the milk recording databases (herd mean annual milk yield per goat, somatic cell count (SCC) and bulk milk bacterial count), and the material included 235 herds. Associations with housing factors were tested at herd level and at individual goat level. Housing in insulated buildings with no access to outdoor areas during the winter season, expanded metal grating and no use of bedding predominated. None of the housing factors evaluated were significantly associated with milk yield. In herds using water nipples, SCC was lower compared to herds using water bowls. SCC was also lower in herds with milking facilities in separate milking stalls as compared with combined feeding milking stalls in common pens. No significant associations were found between housing factors and bacterial counts, but the counts were lower in herds with high average milk yields per goat.     

Improved milk production through PG–PL system by provision of in‐house shelter management in lactating Murrah buffaloes during winter season

Comprehensive information on the role of β‐casein and plasminogen–plasmin (PG–PL) system in milk secretion of Murrah buffaloes during winter season is lacking, although effects of cold stress can be ameliorated to an extent by altering microclimate at farm level. Hence, this study was aimed to determine the changes in productivity along with PG–PL system of milk, plasma hormones and metabolites of buffaloes during winter (December–January) season under two different management systems. Average minimum temperature and wind chill index during this season were 7.02 and 12.74 °C respectively. Buffaloes were divided in two groups of six animals each: control and treatment, where treatment group animals were placed in‐house with floor bedding of paddy straw and the control group animals in loose housing system without straw bedding. Physiological responses were recorded, and milk and blood samples were collected at weekly intervals for six‐week experimental period. Under in‐house management system, buffaloes experienced better comfort by alleviating environmental stress as their physiological responses such as respiration rate and pulse rate were significantly reduced (p < 0.01) as compared to the control, which subsequently resulted higher milk yield by 9.92% (p < 0.05). Analysis of milk samples revealed higher concentration of plasminogen (10.6 vs. 8.05 μg/ml; p < 0.01) and β‐casein (p < 0.05), and lower plasmin level (0.299 vs. 0.321 μg/ml; p < 0.05) in buffaloes under treatment group. It was also found that plasma cortisol, glucose and non‐esterified fatty acids levels were higher (p < 0.01) in control group as compared to the treatment animals by 13.6%, 8.14% and 12.6% respectively. However, milk composition, growth hormone, epinephrine and norepinephrine level in plasma were similar in both the groups. Hence, it may be concluded that provision of in‐house shelter management with floor bedding of paddy straw during winter was effective to minimize environmental stress and improved milk production through manipulation of PG–PL system in buffaloes.     

奶牛乳体细胞数与泌乳月份和乳成分的相关分析

为了解东北垦区规范化养殖牛场奶牛乳体细胞数的水平和分布情况,探析泌乳月份及乳成分与体细胞数之间的关系。利用统计分析软件SPSS 19.0中的GLM和Correlation过程,分析了2012—2013年黑龙江省某牛场的奶牛生产性能测定数据。结果表明,该牛场牛群平均乳体细胞数为14万/m L,有56.70%的奶牛个体乳体细胞数小于20万/m L,6月和10月乳体细胞数较高,10月乳房炎阳性率最高(27.25%)。体细胞数高于15万/m L时,就会造成经济损失,高于50万/m L的经济损失占牛群经济损失的71.45%。体细胞数与产奶量呈负相关,与乳蛋白率呈正相关。该试验结果可为更好地运用DHI体系评价奶牛的生产性能,规范牛群的饲养管理,有针对性地开展乳房炎防治工作提供参考。     

Genetic associations of in-line recorded milkability traits and udder conformation with udder health

Milkability and udder conformation traits of Swedish Holstein (SH) and Swedish Red (SR) cows from 93 herds with automatic milking systems or conventional milking parlors were used to study genetic relationships to lactation average somatic cell score (LSCS) and incidence of clinical mastitis (CM). Estimated genetic correlations between measures of milking speed (average flow rate, milking time and box time) and LSCS ranged between 0.29 and 0.57 and showed that high milking speed is associated with increasing LSCS. Regressions indicated a curvilinear relationship. Genetic correlations between milking speed and CM showed similar values as for LSCS in SH cows, but were inconsistent in SR cows. Shallow udder and strong fore udder attachment were consistently correlated with good udder health. The unfavorable relationships between milking speed and udder health traits should be considered together with a few udder conformation traits when selecting for better milkability.     

A clinical trial to evaluate the effectiveness of antibiotic treatment of lactating cows with high somatic cell counts in their milk

OBJECTIVE: To determine the effectiveness of treatment of lactating cows with high somatic cell counts in milk. DESIGN: Randomised clinical trial. METHODS: Single pooled quarter samples of milk were obtained from cows with somatic cell counts above 500,000 cells/mL on fifty farms. Milk samples were cultured for known mastitis bacterial pathogens. Cows were randomly allocated to treated and untreated groups. Treated cows received both intramammary cloxacillin and parenteral erythromycin. Single pooled quarter milk samples were obtained at 6 weeks after treatment and were cultured for the presence of pathogenic bacteria. The percentage of samples with no growth at the post-treatment culture was used as an estimate of the bacteriological cures for each pathogen type and for each treatment group. Somatic cell counts of cows were compared between treatment groups and within pathogen group. The number of cows that completed a full lactation were compared between each treatment group and within each pathogen group. RESULTS: Treatment had no effect upon bacteriological cures, irrespective of pathogen present or the presence of bacteria during the previous lactation. There was no effect of treatment upon somatic cell count except for cows infected with Streptococcus dysgalactiae in which treatment caused a significant lowering of cell counts. This effect was not present in the subsequent lactation. Treatment of chronically infected cows did not alter the probability of a cow completing a full lactation but did improve the probability of newly infected cows being retained for the next lactation. Twenty-eight of 214 treated cows developed clinical mastitis in more than one quarter after treatment, thus indicating a poor technique by farmers for the insertion of intramammary antibiotics. CONCLUSIONS: Treatment during lactation of cows with high somatic cell counts in milk is ineffective in reducing bacterial infections and in reducing somatic cell counts to acceptable numbers.     

Fungi isolated from bovine udders,and their possible sources

AIM: To identify fungi isolated from infections of the bovine mammary gland, and establish their possible sources.

METHODS: From a herd of 420 cows, milk samples were collected from all quarters at calving and cultured to detect causative organisms. Quarters identified as infected with fungi were further sampled during early lactation. Samples from feedstuffs, the feed pad and ends of teats were also collected and analysed for the presence of fungi.

RESULTS: Eleven of 420 cows were diagnosed with intramammary infections (IMI) caused by yeasts (nine cows, 10 quarters) and moulds (two cows, three quarters). Six of the yeast species had previously been reported as being responsible for mastitis. Elevated somatic cell counts (SCC) were observed in many quarters, but most infections were eliminated spontaneously. Two of the fungi isolated from milk samples were also isolated from feedstuffs and teat swabs, and seven other fungi isolated from milk samples were not isolated from feed, the feed pad or cows' teats.

CONCLUSIONS: Isolation of fungi from the udder is rarely reported in dairy cows in New Zealand. In this herd, contamination of the end of the teat originating from feedstuffs and possibly exacerbated by the use of a feed pad may have led to the establishment of IMI caused by fungi.

CLINICAL RELEVENCE: Fungi are infrequently if ever reported in mastitis trial data or surveys in New Zealand and are probably of little clinical significance.     

Evaluation of Tunisian milk quality in dairy herds: Inter‐relationship between chemical,physical and hygienic criteria

The objective of this paper was to evaluate the global milk quality in Tunisian dairy herds. Samples of milk were analyzed for chemical, physical and hygienic parameters. Milk total solids, fat content and density were consistently correlated and one of them can be used as a chemical indicator of milk quality. The somatic cell count value of 689 × 10³/mL was higher than the recommended threshold. All milk samples were positive for the major pathogen Staphylococcus aureus. These hygienic parameters were related more closely with chloride content, minerals and electrical conductivity, which allows them to be used as indicators of mammary gland infection. It was concluded that milk producers have at hand rapid and easy tools for assessing the overall quality of milk.     

牛TLR4基因的遗传多态性与乳房炎的关联分析

TLR4通过识别病原体而激活免疫细胞，在先天免疫和适应性免疫防御中起着重要作用。以中国荷斯坦奶牛、三河牛和中国西门塔尔牛共397头为研究对象，利用创造酶切位点PCR法扩增243bp的目的片段，通过限制性内切酶HinfⅠ酶切来检测TLR4第3外显子的多态性，结果发现扩增产物的27bp处C到T的突变使得多态位点产生，编码的氨基酸由苏氨酸变为异亮氨酸。A、B2个等位基因在3个群体中均有分布，A等位基因占优势（大于78％），经χ^2适合性检验，三河牛在该位点未达到Hardy-Weinberg平衡状态（P〈0．05）。运用SAS8．2软件采用最小二乘法拟合线性模型，将该基因座不同基因型与奶牛乳房炎进行了关联分析，结果表明：AA基因型为乳房炎抗性基因型（P〈0．05），A等位基因为乳房炎抗性的有利基因。     

Association of BoLA‐DRB3 alleles with mastitis resistance and susceptibility in Japanese Holstein cows

In this study, 714 cows from 26 dairy herds were reclassified as healthy or mastitic cows on the basis of long‐term somatic cell count (SCC) in milk. Cows with more than three consecutive lactation records of SCC from the first or second to fifth lactation, were selected, and their BoLA‐DRB3 (DRB3) alleles were identified using polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) method. Cows with an SCC of < 200 000 cells/mL in all monthly records were classified as healthy (n = 91). Cows with an SCC of > 300 000 cells/mL in two consecutive tests or four non‐consecutive tests or cows with an SCC of > 500 000 cells/mL in any one test during lactation, regardless of parity, were classified as mastitic (n = 201). Mastitic cows (n = 153) from another 40 herds were considered to be infected if bacteriological testing revealed mastitis pathogens in milk. Their DRB3 alleles were identified using PCR‐sequence‐based typing (PCR‐SBT). The differences in DRB3 allelic frequencies between healthy cows and cows with various degrees of mastitis were re‐investigated. Moreover, the associations of various amino acid motifs in DRB3 alleles with resistance or susceptibility to mastitis pathogens were re‐examined. DRB3.2*8(DRB3*1201) and DRB3.2*16(DRB3*1501) alleles were found to be associated with susceptibility, while DRB3.2*22(DRB3*1101), DRB3.2*23(DRB3*2703), and DRB3.2*24(DRB3*0101) alleles were found to be associated with resistance.     

奶牛隐性乳房炎乳汁部分成份的检测与评估

对两群临床健康的３３６ 头泌乳奶牛的混合乳进行了隐性乳房炎、乳汁体细胞数、乳脂率和蛋白质检测。３３６ 份混合乳样经青海乳房炎试验（ＱＭＴ） 检测,检出乳房炎阴性牛（ 包括可疑反应）１７５ 头（５２０９ ％ ） ,乳房炎阳性牛１６１ 头（４７９１ ％ ） 。乳房炎阴性牛的乳汁体细胞数为２３１７ ±１２９９ 万／ｍｌ,乳脂率为３６０ ％ ±０７６ ％ ,乳蛋白质为２９３ ％ ±０３４ ％ ,乳房炎阳性牛乳汁体细胞数为１８２ 万／ｍｌ±１５２２７ 万／ｍｌ,乳脂率为３４０ ％ ±０７０ ％ ,乳蛋白质为３０５ ％ ±０３５ ％ 。乳房炎阴性牛乳汁体细胞数,乳蛋白极显著低于乳房炎阳性牛（Ｐ＜ ００１） ,而乳脂率显著高于乳房炎阳性牛（Ｐ＜ ００５） 。