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The role of ketone bodies on chemotactic capacities of leukocytes was characterized in two experiments. Experiment I was performed to investigate the association between serum beta-hydroxybutyrate concentrations (BHB) and in vitro chemotaxis of leukocytes. Cows were divided into low-BHB, medium-BHB, and high-BHB ones and classified according to their BHB. Leukocytes from high-BHB cows had a significantly lower chemotactic differential than leukocytes from low-BHB cows (p < 0.01). The effect of adding ketone bodies into in vitro chemotaxis cultures on leukocytes chemotaxis was studied in Experiment II. Either individual or a combination of commercial ketone bodies - sodium salts of BHB (BHBA), lithium salt of acetoacetate (ACAC), and acetone (Acetone) - were diluted in culture media and divided into eight concentrations corresponding to concentrations of bovine subclinical and clinical ketosis. For leukocytes from medium- and high-BHB cow, the chemotactic indexes of leukocytes were reduced by ACAC and Acetone. Chemotactic differentials of cultures with ACAC and acetone supplementation from both sources of leukocytes were significantly lower than that of the control culture (p < 0.05). For leukocytes from high-BHB cows, chemotactic indexes were suppressed in a ketone-body environment. In conclusion, leukocytes from naturally-occurring ketotic cows have lower chemotactic differentials than those from non-ketotic cows, and a chemotactic capacity indicated by a chemotactic differential is impaired when leukocytes migrate in an environment with ketone bodies in vitro.  相似文献   
2.
Tropical Animal Health and Production - The aims of this study were to determine the effects of seasonality on yields and quality of bovine abattoir-derived oocytes and their in vitro maturation...  相似文献   
3.
The objective of this study was to determine the relationship between body-condition score and postpartum reproductive efficiency in dairy cattle. Data on body-condition score, reproduction, diseases, and production from 1404 lactations of 639 cows, calving between January 1984 and November 1996 on a commercial farm, were used. The Cox proportional-hazards model with time-dependent covariates was used to qualify the relationship between body-condition score on a scale of 1 to 5 and risks of first insemination and pregnancy. Cows with body condition at calving <3 had lower first-insemination risks. Loss of body-condition score between calving and 45 days after calving was associated with increased days open and days-to-first insemination. Cows with body-condition scores <2 after Day 45 and before first insemination were less likely to be inseminated and become pregnant compared with cows that had higher body condition. Milk yield, mastitis, lameness, milk fever and genital infection were associated with a reduction in reproductive efficiency. The results indicated that loss of body-condition and actual body-condition scores before conception or first insemination or both can be used as a prognosis for days open and days-to-first insemination in dairy herds.  相似文献   
4.
Hyperketonemia and the impairment of udder defense: a review   总被引:1,自引:0,他引:1  
The objective of this study was to review the possible relationships between hyperketonemia and the function of phagocytes with respect to the bovine udder defense mechanism. We hypothesize that an increased incidence of clinical mastitis in high-producing cows is caused by the impairment of the udder defense mechanism during hyperketonemia. First, we review the acute phase of udder defense mechanisms after intramammary infection. The physiological changes of cows in negative energy balance are subsequently discussed. Finally, possible relationships between udder defense and physiological changes during negative energy balance, especially hyperketonemia, are reviewed. The three stages of an acute phase of udder defense are: (1) immediately eliminating invading pathogens by phagocytes, (2) releasing inflammatory substances, especially chemoattractants, and (3) migration of polymorphonuclear leukocytes into the infected udder. Leukocytes from hyperketonemia subjects show a lower capacity of the phagocytic defense mechanism. In addition, the phagocytic and bactericidal capacities of neutrophils are reduced when these cells are acting in the presence of high concentrations of ketone bodies. Lower amounts of cytokine production after bacterial infection are observed in ketotic subjects. The chemotactic capacity of blood leukocytes is impaired in leukocytes obtained from ketotic cows. Lower numbers of blood leukocytes are observed in ketotic cows. In conclusion, the impairment of the udder defense mechanism in negative energy balance cows seems related to hyperketonemia.  相似文献   
5.
Water, Air, & Soil Pollution - A vermifilter (with earthworms, VF), with a conventional biofilter (no earthworms, BF) as a control, was established to examine the survival state and...  相似文献   
6.
Goats are important domestic animals in the south of Thailand due to the minimal cost of rearing and maintaining them, and their production of both meat and milk. Toxoplasmosis is one of the most threatening parasitic zoonoses and the causative agent Toxoplasma gondii uses a wide range of warm-blooded intermediate hosts including the goat. The objective of this study was to assess the seroprevalence of antibodies to T. gondii in goats of Satun Province in Thailand. A total of 631 goat sera were examined for antibodies against toxoplasmosis with commercial latex agglutination test kits (Toxocheck-MT 'Eiken'). Of these, 176 (27.9%) were found to be positive to T. gondii; antibody titers ranged from 1:64 to 1:4096 (1:64 cut-off). Female goats were 1.73 times more likely than male to be seropositive (odds ratio [OR]=1.73; 95% confidential interval [CI]=1.11, 2.73). Dairy goats were more likely to be seropositive than meat goats (OR=1.36; 95% CI=0.84, 2.20). Goats were infected with T. gondii with acquisition of age because older goats were more likely to be seropositive than young goats under 1-year-old (for 1-2 years, OR=19.6; 95% CI=0.92, 4.15, for >2 years, OR=2.70; 95% CI=1.26, 5.80). The high seroprevalence of T. gondii antibodies found in the present study suggested widespread exposure of goats in Satun Province to T. gondii.  相似文献   
7.
A cross-sectional study was carried out from May to September 2011 on 35 smallholder dairy farms in Chiang Mai, Thailand, to identify the quarter, cow, and farm factors that relate to intramammary infections (IMI) from major specified pathogens, compared to infections from minor pathogens. Data on general farm management, milking management, and dry cow management were recorded for each herd. Quarter milk samples were collected from either clinical or subclinical mastitis quarters. Dependent variables were binary data defining the specified major pathogens, including Streptococcus agalactiae (7.1 %), Streptococcus uberis (9.4 %), Streptococcus dysgalactiae (4.0 %), and other streptococci (16.7 %), as a case, and all minor pathogens as a control, in each dependent variable. The occurrence of S. agalactiae IMI was lower in first-parity cows and cows with short milking time. Cows with body condition score (BCS) <2.5 had higher occurrence of S. agalactiae IMI. The occurrence of S. uberis IMI was higher in quarters with California mastitis test (CMT) score 2, score 3, and having clinical mastitis and in farms with increasing age of vacuum system. Quarters with CMT score 3, having clinical mastitis, cow with manual milking after detaching milking cluster, and farms with high bulk milk somatic cell counts (BMSCC >500,000 cells/ml) had higher occurrence of S. dysgalactiae IMI. For other streptococci, quarters having clinical mastitis, BCS <2.5, and pulling down of milking cluster while milking increased occurrence of other streptococci IMI relative to minor pathogen IMI. These results highlight the importance of individual cow factors, milking characteristics, and BMSCC in determining the risk of IMI from major pathogens.  相似文献   
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