Disease,production and culling in Holstein-Friesian cows II. Age,season and sire effects

Effects of age, season and sire on the occurrence of common diseases of Holstein-Friesian cows were evaluated in a two and a half year study. The data were from 2875 lactation records from 2008 cows in 32 commercial dairy herds within a 50 mile radius of Guelph, Ontario.Age patterns for all disease conditions were determined using χ² or quadratic regression analyses. Linear increases with age were observed for milk fever, mastitis requiring local therapy only, cystic ovaries and foot and leg problems. Quadratic relationships with age were observed for ketosis (clinical and subclinical), mastitis requiring systemic therapy, subclinical mastitis, dystocia, respiratory diseases and traumatic reticulo-peritonitis. No consistent age patterns were found for retained placentas, reproductive tract infections, abomasal displacements, teat injuries, digestive disorders and abortions.Seasonal patterns were evaluated using a formal statistical test for the seasonality of events. Significant peaks were found in the risk of ketosis and cystic ovaries during the winter, and in the risk of teat injuries in the late winter or early spring. Seasonal patterns, more complex than a simple unimodal pattern, were observed for mastitis requiring local therapy only, traumatic reticulo-peritonitis and abortions.Heritabilities were determined for 9 disease conditions. All heritabilities were low or 0 with the exception of clinical ketosis (h² = 0.31).     

Monoclonal antibodies potentially detecting bovine MHC products

Three monoclonal antibodies reacting with lymphocytes from some but not all cattle have been studied to find whether they detect internationally agreed BoLA workshop specificities defined by bovine alloantisera.Two of the monoclonals reacted with BoLA w6 but gave too many cross reactions to be used as typing reagents. The third showed no BoLA specificity.     

黄牛正常胆囊及牛黄胆囊组织学观察

对111份正常黄牛及12份天然牛黄牛的胆囊,进行了组织学光镜观察。结果发现,在正常情况下黄牛胆囊即有轻度水肿、炎细胞浸润的胆囊炎病变;牛黄胆囊均有囊壁增厚、炎细胞的显浸润、粘液浆液腺显著增生的慢性胆囊炎。同时胆汁很少,极度粘稠。此外本文对胆囊病变与成黄的关系作了分析。     

Field drainage, soil water management and flood hazard

Abstract. The efficient management of clay soils depends on the rapid disposal of water following rainfall. Winter storm outfall hydrographs of under drained catchments ranging in size from 0.44 ha to 7.2 km² are given, illustrating the drainage response of a Windsor Series soil. The response time of different sized catchments is discussed in relation to potential flood hazard arising from drainage improvements of agricultural land. Comparison is made with other soils to reveal broadly similar patterns of drainflow, with peak flow occurring typically between 1 and 4 hours after the mid-point of a storm. Despite large fluxes of water through the soil profile, the water content of the soil within the catchment of an individual tile lateral is shown to vary only by small amounts both during and after a single rainstorm and over a drainage season.     

Evaluation of tulathromycin for the treatment of pneumonia following experimental infection of swine with Mycoplasma hyopneumoniae

Tulathromycin was evaluated in the treatment of pneumonia in weaned pigs inoculated intranasally with Mycoplasma hyopneumoniae. Five days postchallenge, the pigs were randomized to treatment with a single IM administration of saline, a single IM administration of tulathromycin (2.5 mg/kg; day 0), or three IM administrations of enrofloxacin (5.0 mg/kg; days 0, 1, 2). Pigs were necropsied on day 12 or 13. Unchallenged controls remained healthy with no lung pathology. Compared with saline, coughing, mean lung lesion score, and proportional lung weight were significantly reduced and weight gain was significantly greater for tulathromycin-treated pigs (P < .05). Compared with enrofloxacin, there were no significant differences in proportional lung weight or weight gains, but coughing and lung lesion scores were greater for tulathromycin-treated pigs (P < .05). Tulathromycin was effective in the treatment of pneumonia following experimental infection with M. hyopneumoniae.     

Evaluation of the stability of Ostertagia ostertagi ELISA microtitre plates over time using cow milk samples

The objective of this study was to assess the stability of ELISA plates prepared with one of three blocking agents and used with one of two conjugates at various time intervals after preparation of the plates. Two of the blocking agents used were commercially available: one termed stabilgaurd (stab) and one manufactured by SVANOVA Biotek AB Inc. (svan). The third blocking agent used was bovine serum albumin (bsa). A polyclonal rabbit anti-bovine IgG (poly) and an anti-bovine IgG monoclonal (mono) conjugate were used. Eighteen composite individual cow milk samples collected late in lactation (200-400 days in milk) were used in this study. An indirect microtitre plate ELISA that used the Ostertagia ostertagi antigen was used to quantify antibodies against the parasite, present in the milk samples. Each of six blocking agent/conjugate combinations (called systems) were used to test 18 milk sub-samples at 1, 4 and 24 weeks after blocking the plates. Plates blocked with stab and svan were kept at room temperature and an additional set were incubated at 37 degrees C so as to mimic long term storage (about 1 year) and tested only once at 4 weeks. Those blocked with bsa were frozen at -20 degrees C. Concordance correlation coefficients (CCC) and reproducibility were used to assess the agreement between test results conducted on the same milk sample at the various test-times using a particular system. Generally, there was good agreement between tests conducted at different times for all systems. However, the svan-mono and bsa-poly systems had the best agreement with overall CCC values of 96% and 93%, respectively. The svan-poly system had the lowest CCC of 75%. The CCC and reproducibility ranked the systems in a similar way. The high CCC between tests done using plates kept at room temperature and ones incubated at 37 degrees C, suggested that plates would be stable up to a year after blocking. The storage of plates blocked with svan and stab agents under room temperature, makes them more convenient to use and transport relative to bsa-blocked plates that have to be frozen.     

Effects of treatment with omeprazole or ranitidine on gastric squamous ulceration in racing Thoroughbreds

OBJECTIVE: To compare the effects of oral administration of omeprazole and ranitidine on gastric squamous ulceration in Thoroughbreds in race training. DESIGN: Modified crossover study. ANIMALS: 60 Thoroughbreds in race training with gastric squamous mucosal ulceration. PROCEDURE: Horses were randomly allocated into 3 groups. Group 1 received no treatment for 28 days followed by administration of omeprazole (4 mg/kg [1.8 mg/lb], PO, once daily) for 28 days; group 2 received omeprazole (4 mg/kg, PO, once daily) for 28 days followed by no treatment for 28 days; and group 3 received ranitidine (6.6 mg/kg [3.0 mg/lb], PO, q 8 h) for 28 days followed by administration of omeprazole (4 mg/kg, PO, once daily) for 28 days. Ulceration was assessed endoscopically at days 0, 28, 42, and 56. Lesions were scored from 0 (no ulceration) to 3 (severe ulceration). RESULTS: After the initial 28 days of treatment, the decrease in ulcer severity was significantly greater after omeprazole treatment than after ranitidine treatment. Ulcer severity decreased significantly in group 3 horses after 14 days of treatment with omeprazole. Discontinuation of omeprazole resulted in worsening of ulcer scores; however, ulcer scores at completion of the study were less than at day 0. Horses that received omeprazole after 28 days of ranitidine treatment had a further reduction in ulcer severity. CONCLUSIONS AND CLINICAL RELEVANCE: Omeprazole was more effective than ranitidine in healing gastric squamous ulcers in Thoroughbreds in race training. Improvement was detected by 14 days and persisted in most of the group 2 horses for at least 28 days after omeprazole treatment was discontinued.