The in vitro efficacy of SunSmile® Fruit & Vegetable Rinse against pathogenic strains of Prototheca algae that cause mastitis in cows

The research concerns algae of the genus Prototheca. They are found in the natural environment and they can cause a disease in animals and humans called protothecosis. The aim of the study was to evaluate the in vitro activity of the fruit and vegetable rinse agent SunSmile^® Fruit & Vegetable Rinse (Sunrider International) against P. zopfii isolates. The materials consisted of ten P. zopfii strains isolated from the milk of cows with mastitis. The following antifungal chemotherapeutic agents were also used in the study for comparison: nystatin, ketoconazole, amphothericin B, miconazole, clotrimazole, econazole, fluconazole, and flucytosine. The tube dilution method were used to evaluate the effect of a fruit and vegetable rinse agent and the disc-diffusion method to evaluate the effect of antifungal chemotherapeutic agents on P. zopfii strains. All tested strains of P. zopfii were susceptible to the action of the SunSmile^® agent. The MMC was in the range of 0.0024–0.0190%. The SunSmile^® Fruit & Vegetable Rinse can be used in prevention of mastitis in cows and in human protothecosis due to its safe, natural composition and efficacy.     

乳牛血清中人HBV样颗粒性质的初步研究

对免疫电镜发现的乳牛血清中人HBV样颗粒,进一步作了形态学、血清学研究。此颗粒较人HBV颗粒略小。7份阳性血清中,HBsAg(7/7)、HBeAg(6/7)、HBcAg(6/6)、抗-HBs(1/7)阳性,但PHASR、抗-HBc,抗-HBe、32P-人HBVDNA杂交试验及人HBV DNA多聚酶活性均阴性。与马抗-HBs血清作琼脂糖双向扩散试验时出现1～3条沉淀线,其中一条与HBsAg产生的沉淀线融合。     

Determination of highly soluble L-Carnitine in biological samples by reverse phase high performance liquid chromatography with fluorescent derivatization

This study was performed in order to validate an effective high performance liquid chromatograpy (HPLC) method to determine L-carnitine in biological samples such as plasma, milk and muscle in cows. An L-carnitine derivative for fluorescence absorption was synthesized with 1-aminoanthracene (16 mg/mL in acetone) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDAC; 160 mg/mL in 0.01 M NaH2PO4 buffer) as a precolumn fluorescent derivative reagent. gamma-Butyrobetaine HCI was used as an internal standard. A reversed-phase column with fluorescence detection at the excitation and emission wavelengths of 248 and 418 nm were used. The mobile phase consisted of 30% acetonitrile with 0.1 M ammonium acetate in water (pH 3.5) adjusted with acetic acid and delivered at a flow rate of 1.5 mL/ min. The L-carnitine concentration in plasma, milk and muscle samples of cows after oral feeding with 24 g L-carnitine/day for 2 months was then determined. All biological samples were deproteinated by barium hydroxide and zinc sulfate heptahydrate before the derivative reaction. Blank cow plasma was dialyzed using cellulose membrane for standard calibration. The calibration curve showed good linearity (r2 > 0.999) over the concentration range of 50 to 5000 ng/mL. The precision and accuracy were also satisfactory with less than 15% intra- and interday coefficiency of variations. The peaks of L-carnitine and internal standard in HPLC chromatography were successfully separated in plasma, milk and muscle samples of cows. The current derivatization method of L-carnitine for fluorescence detection was simple and adequately sensitive and could be applied to determine L-carnitine in biological samples.     

Age-associated changes in bovine oocytes and granulosa cell complexes collected from early antral follicles

Purpose

To assess the age-associated changes in oocytes and granulosa cells derived from early antral follicles (EAFs).

Method

Gene expression analysis of granulosa cells of the EAFs using a genome analyzer (Illumina) and in vitro culture of oocyte-granulosa cell complexes (OGCs) of EAFs (400–700 μm in diameter) collected from ovaries of aged (>120 months) and young (<50 months) cows.

Results

Gene expression profiles in granulosa cells of EAFs of aged cows, which included changes in genes that encode chaperone proteins and antioxidants. In vivo development of EAFs, as determined by oocyte diameter of EAFs and AFs (3–6 mm in diameter), appeared to be impaired in aged cows and the OGCs of aged cows contained low GSH compared to younger counterparts. When the OGCs were cultured in a medium containing low estradiol (E_2, 0.1 μg/mL), the ratio of antrum formation was higher for OGCs from aged animals than that from young animals, while higher abnormal fertilization rate and lower total cell number of the blastocysts were observed in the OGCs of aged cows compared with those of young cows. On the contrary, when the OGCs were cultured in a medium containing 10 μg/mL E₂, the ratio of antrum formation and fertilization outcome was comparable between the two age groups, whereas the total cell number of the blastocysts was still low in the aged group.

Conclusion

Aging affects the gene expression profiles of the granulosa cells, and impairs in vitro developmental ability of OGCs collected from EAFs.     

奶牛附红细胞体病的流行病学调查

采用镇检法检测奶牛颈静脉血附红细胞体(附红体)感染情况,共检测4个奶牛场128头奶牛,发现4个奶牛场的奶牛均有不同程度的感染,平均感染率为58.59％(75/128);抽查7对母牛及其新生犊牛颈静脉血进行垂直传播调查,结果其中5对母、犊同时检出附红体。对抗凝血中奶牛附红体进行4℃冰箱保存试验,观察到66份保存30天后仍有活力;用奶牛附红体阳性抗凝血人工感染25份阴性抗凝血,4℃冰箱保存,2天后观察到阴性抗凝血全部变为阳性,15天后观察转为强阳性。     

Effect of Water Deprivation on Eating Patterns of Lactating Cows Fed Grass and Corn Pellets Ad Lib

The present study investigated the effect of 48 h of water deprivation on eating behavior of 12 lactating cows fed grass and corn pellets ad lib. Water deprivation reduced grass and corn pellet intake significantly, with corn pellet intake decreasing earlier than grass intake. The reduction of feed intake was entirely due to a reduction of meal size for both grass and corn-pellet meals. The size of the first meal of the water deprivation period was already reduced by about 30%. Grass-meal frequency increased, whereas corn-pellet meal frequency decreased during water deprivation. Water deprivation also decreased live weight and milk yield by about 12 and 30%, respectively. All parameters returned to baseline values with rehydration. With ad lib access to feed and water, 77% of drafts occurred in relation to meals, but the number of meals clearly exceeded the number of drafts. The results demonstrate that water deprivation rapidly leads to premature meal termination. This is in line with the assumption that an enhanced prandial increase in ruminal fluid osmolality contributes to dehydration-induced hypophagia. Yet, further studies are necessary to prove this assumption and to better understand the complex relationships between eating and drinking in ruminants.     

Effect of a Selenium-Deficient Diet on Blood Values of T3 and T4 in Cows

Pastures in the south of Chile have been shown to be selenium deficient, and as selenium is a component of deiodinase type 1, which is necessary for the synthesis of triiodothyronine (T3) at peripheral levels, the effect of selenium deficiency on the blood concentration of theses hormones in cows was studied. Twelve pregnant Friesian cows were randomly allocated into two homogeneous groups of six animals each - selenium supplemented and selenium deficient. The selenium deficient diet consisted of 11.5 kg of hay, 500 g of soya bran, 150 g of mineral mix (without selenium), 500 g of fat for animal feeding, and was given from day 15 of lactation until the end of the study. A commercial concentrate (Cosetan) and urea was also given according to lactation requirements (up to 5 kg and up to 120 g, respectively). The selenium content was 0.05 ppm of dry matter (equivalent to 18% of the daily requirements). The supplemented group was injected subcutaneously with 1 mg Se/kg, using the commercial product Deposel (1 ml/50kg). Blood samples were obtained by coccygeous vein venepuncture before supplementation (prepartum basal values) and thereafter every 15 days. GSH-Px activity in plasma was measured using a HITACHI 4020 spectrophotometer. Serum T3 and thyroxine (T4) concentrations were measured by electrochemiluminiscence. ANOVA, Tuckey test and Student’s t-test were used to establish the significance of the intra group differences, with p=<0.05 being considered significant. There were no significant differences in blood values of T4 in either the supplemented or non-supplemented groups during pregnancy and lactation. However the blood values of T4 decreased significantly (p=<0.05) during days 30–60 of lactation to values below the reference range. The T3 serum concentrations in the supplemented group of cows were significantly lower (p=<0.05) at 60, 90 and 150 days of lactation than cows that had been supplemented with selenium.     

Bovine β‐lactoglobulin in hypoallergenic and ordinary infant formulas measured by an indirect competitive ELISA using monoclonal and polyclonal antibodies

Whey protein concentrates of cows’ milk are used widely in dairy products including infant formulas. A major component is the potent allergen bovine β‐lactoglobulin (BLG). Two easy and sensitive substrate‐amplified indirect competitive ELISAs for BLG, one using a rabbit polyclonal antibody (PAb) K97 raised against heat‐treated BLG, and another using a monoclonal antibody (MAb) 61B4 specific to the epitope Thr¹²⁵‐Lys¹³⁵ are described. Furthermore, a new whey protein test kit specific for BLG was tested. A new video‐based digital image processing system was used to read, evaluate and calculate data from the microtitre plates. The detection limit was 0.08 ng ml^‐1 for the PAb assay, which was sufficient for the use of this assay as a test method for ‘milk‐free’ products. The detection limit was 3.2 ng ml^‐1 for the MAb assay and 144 ng ml^‐1’ for the commercially available kit. Thirteen commercially available infant formulas on the Danish market, including four hypoallergenic products and cows’ milk, were tested. The BLG content varied from 0.2 to 727 μg ml^‐1, quantified with the PAb assay. The hypoallergenic infant formula with the lowest amount of BLG was Nutramigen containing about 0.1% residual BLG compared with the ordinary infant formula Nidina 1. The knowledge of residual BLG content in hypoallergenic infant formulas is important for a more qualified nutritional recommendation to parents with children genetically susceptible to allergies and for quality assurance of infant formulas claimed to be hypoallergenic.     

某奶牛场高危人群及牛群布鲁杆菌病检测结果分析

目的了解某奶牛场高危人群和奶牛群中布鲁杆菌病的感染状况。方法采用琥红平板凝集试验和试管凝集试验检测有奶牛接触史人群和感染者密切接触人员以及奶牛的血清样本,以全乳环状试验检测新鲜乳样。结果该奶牛场高危人群布鲁杆菌抗体阳性的检出率为6.7％（3／45）,抗体阳性者均为挤奶工人;奶牛群布鲁杆菌抗体阳性的检出率为2.2％（4／180）;新鲜乳样中均未检出布鲁杆菌。结论该奶牛场中高危人群和奶牛群已存在布鲁杆菌感染,应采取有效措施,控制疫情蔓延。     

Crystallization and the number of neutrophils increase in the cervical mucus as parturition approaches in dairy cows

The aim of the present study was to determine changes in the crystallization and cytology of cervical mucus in late gestation in dairy cows. Eleven 7-month pregnant Holstein cows with a sound reproductive history were used in this study. Samples of cervical mucus were collected on 53±3, 38±3, 23±3, 12±2, 8±1, 5±1 and 2±1 days before parturition for cytology and examination of crystals. Coccygeal blood samples were also collected after each cervical mucus sampling for determination of plasma estrogen and progesterone concentrations. A sample of nasal secretions was also collected after each blood sampling for examination of crystals. The thin cervical smears were Giemsa stained for cytological examination and the thick smears of cervical and nasal mucus were also evaluated for crystallization. The results of the present study showed an increased (p<0.05) percentage of neutrophils and typical crystals in the cervical mucus as parturition approached. This coincided with the gradual rise of the plasma estrogen concentrations and the gradual decline of the plasma progesterone concentrations in the last 2 weeks before the onset of parturition. Further, a significant positive correlation was observed in the changes of the crystallization pattern between nasal and cervical mucus samples (p<0.05; r=+0.86). In conclusion, crystallization and increased neutrophils in the cervical mucus in late gestation could be related to impending parturition in dairy cows.