This study investigated the diagnostic and surgical management of urachal abscessation involving the urinary bladder in three cattle aged >18 months. While the abdominal floor or paralumbar fossa are typically considered for accessing the urachus and bladder in calves and heifers, the distance is too great to perform the procedure under direct vision in adult cows. Therefore, a novel preinguinal approach was used for access in cows with urachal abscesses after 18 months. Access was successfully achieved in all the three cows through a preinguinal incision to the urachal abscess at the apex of the bladder. However, in cases wherein the abscess and adhesions are severe, removal may be challenging or may necessitate a combined median or paramedian approach.

The objective in the present study was to assess the ventral tail base surface temperature (ST) for the early detection of Japanese Black calves with fever. This study collected data from a backgrounding operation in Miyazaki, Japan, that included 153 calves aged 3–4 months. A wearable wireless ST sensor was attached to the surface of the ventral tail base of each calf at its introduction to the farm. The ventral tail base ST was measured every 10 min for one month. The present study conducted an experiment to detect calves with fever using the estimated residual ST (rST), calculated as the estimated rST minus the mean estimated rST for the same time on the previous 3 days, which was obtained using machine learning algorithms. Fever was defined as an increase of ≥1.0 °C for the estimated rST of a calf for 4 consecutive hours. The machine learning algorithm that applied was a random forest, and 15 features were included. The variable importance scores that represented the most important predictors for the detection of calves with fever were the minimum and maximum values during the last 3 h and the difference between the current value and 24- and 48-h minimum. For this prediction model, accuracy, precision, and sensitivity were 98.8%, 72.1%, and 88.1%, respectively. The present study indicated that the early detection of calves with fever can be predicted by monitoring the ventral tail base ST using a wearable wireless sensor.

The present study assessed the economic loss due to treatment of bovine respiratory disease (BRD) in Japanese Black calves that were introduced to a backgrounding operation from the age of 3 to 4 months until the age of 10 months. The data collected from a backgrounding operation in Miyazaki, Japan included the records of 2,690 animals entering the farm from 2013 to 2018. The treatment duration was defined as the number of days from the beginning to end of treatment. The cost of treatment was defined as the total cost of treatment during the treatment duration. The average incidence of BRD was 54.6%, and the relative frequency of calves that had BRD once, twice, and three or more times until they left the farm was 64.4%, 26.8%, and 8.8%, respectively (total recorded diagnoses of BRD: 2,494). Among the 2,494 recorded diagnoses, the average and median duration of treatment of BRD was 5.9 days and 3.0 days, respectively. The average and median cost of treatment was 7,767 and 5,600 Japanese yen, respectively. A prolonged duration of treatment and high cost of treatment were associated with BRD relapse, steers, and early stage of production (P<0.05). At the studied farm, the total cost of treatment during the 6-year study period was 19,658,988 yen, and the annual cost was approximately 3 million yen. In summary, the present study showed that BRD had a large economic impact in this backgrounding operation.

市場導入肥育素牛から気管支肺胞洗浄液(BALF)を採取し,微生物学的に検査するとともに,供試牛の導入後治療状況を調査した.BALFからの細菌分離検査では,Pasteurella multocida 及びMycoplasma bovis が分離された.また,ウイルス遺伝子検査では牛Respiratory syncytial(RS)ウイルス遺伝子が検出された.供試牛の導入後治療状況を調査した結果,牛RSウイルス遺伝子が全頭に確認された牛群では導入後に牛呼吸器病症候群治療を受けるまでの期間が早かった.これらの知見は,導入後の牛の気管支肺胞領域に肺炎原因菌あるいは原因ウイルスが存在することを示しており,予防としてのワクチネーションの徹底や使用する抗菌剤の的確な選定を含め,治療方針の決定に重要であると考えられた.

Bovine respiratory disease (BRD), a common and costly disease of beef cattle, has various causes. In Japan, Japanese Black calves aged 3-4 months were introduced to a backgrounding operation that raises calves until age 10 months. We assessed whether any associations relating to the calf information on arrival at the backgrounding operation and BRD incidence in Japanese Black calves exist. The data collected from a backgrounding operation in Miyazaki (Japan) included the records of 1843 animals entering the farm during 2012-2016. The information collected on arrival at the backgrounding operation was calf sex, age, blood line, weight and chest circumference, and the arrival season. Mixed-effect multivariable logistic regression modeling was applied to these data. The dependent variable was whether or not a calf showed the clinical signs of BRD and was subsequently treated with an antimicrobial between farm entry at 3-4 months of age and farm exit at 10 months of age (1 or 0). The first diagnosis of BRD after arrival was counted in this study. Average BRD incidence was 52.5 %, the relative frequencies of which at 0-30, 31-60 and 0.05). Calves of <= 125 days old on farm arrival had higher BRD incidence than those >= 148 days old (P < 0.05). Thus, various factors on arrival at the backgrounding operation were found to be associated with BRD incidence in Japanese Black calves. It is important to carefully observe high-risk calves and monitor them for the clinical signs of BRD at the earliest opportunity on arrival at a backgrounding operation.

This study aimed to analyze the pharmacokinetics of enrofloxacin (ERFX) and its metabolite ciprofloxacin (CPFX) in plasma, as well as their migration to, and retention in, the epithelial lining fluid (ELF) and alveolar cells within the bronchoalveolar fluid (BALF). Four healthy calves were subcutaneously administered a single dose of ERFX (5 mg/kg). ERFX and CPFX dynamics post-administration were analyzed via a non-compartment model, including the absorption phase. The Cmax of plasma ERFX was 1.6 ± 0.4 µg/ml at 2.3 ± 0.5 hr post-administration and gradually decreased to 0.14 ± 0.03 µg/ml at 24 hr following administration. The mean residence time between 0 and 24 hr (MRT0–24) in plasma was 6.9 ± 1.0 hr. ERFX concentrations in ELF and alveolar cells peaked at 3.0 ± 2.0 hr and 4.0 ± 2.3 hr following administration, respectively, and gradually decreased to 0.9 ± 0.8 µg/ml and 0.8 ± 0.5 µg/ml thereafter. The plasma half-life (t1/2) of ERFX was 6.5 ± 0.7 hr, while that in ELF and alveolar cells was 6.5 ± 3.6 and 7.4 ± 4.3 hr, respectively. The Cmax and the area under the concentration-time curve for 0–24 hr for ERFX were significantly higher in alveolar cells than in plasma (P<0.05). These results suggest that ERFX is distributed at high concentrations in ELF and is retained at high concentrations in alveolar cells after 24 hr in the BALF region; hence, ERFX may be an effective therapeutic agent against pneumonia.

本研究では，臨床的に重症慢性肺炎と診断された黒毛和種牛50頭から鼻咽頭スワブ（Swab）及び気管支肺胞洗浄液（BALF）を採取し，細菌分離とともに，その薬剤感受性を調査した．Swab及びBALFからはおもにMycoplasma bovis 及びPasteurella multocida が分離されたが，同一牛において両検体から同一細菌種が分離された割合は比較的低かった．また，BALFから分離されたM. bovis 及びP. multocida は，おもにフルオロキノロン系抗菌薬に感受性であったが，Swabから分離された同2菌種の同系抗菌薬に対する薬剤感受性は低かった．以上より，重症慢性肺炎罹患牛の鼻咽頭領域及び気管支肺胞領域からは，おもにM. bovis 及びP. multocida が分離されるが，同一供試牛から分離された同一菌種の細菌であっても，薬剤感受性が異なる可能性があることから，重症慢性肺炎罹患牛においてSwabによる肺炎原因菌の推定には慎重を要すると思われた．

The purpose of this study was to clarify the distribution of marbofloxacin (MBFX) within the bronchoalveolar region of calves. Four clinically healthy calves were intramuscularly injected with a single dose of MBFX (2 mg/kg). Samples of plasma and bronchoalveolar lavage fluid (BALF) were obtained for each calf at 0 (before administration), 1, 2, 6 and 24 hr after injection of MBFX. The injections and series of sample collections were conducted and repeated again after two weeks. The results show that the MBFX concentrations in the pulmonary epithelial lining fluid (ELF) were significantly higher than that in plasma and in alveolar cells at 2 hr after injection (P< 0.05). For concentrations of MBFX within the ELF, the mean area under the MBFX concentration curve calculated during the 0 to 24 hr timeframe (AUC(0-24)) was significantly higher than the mean determined from samples collected from the plasma (P< 0.05). These results suggest that intramuscularly injected MBFX was well distributed in the bronchoalveolar region.

市場導入肥育素牛の牛呼吸器病症候群の治療状況を調査した．また気管支肺胞洗浄液，気管洗浄液，鼻腔スワブを採取し細菌学的に解析した．調査期間中に408頭の肥育素牛が導入され，導入後2週間以内に治療された牛は64頭であった．治療頭数割合は冬季で多くなり，発症に至る日数は春季で短くなる傾向があった．気管支肺胞洗浄液からは，2013年の6頭による調査では非発熱供試牛（対照牛）では1頭のみからPasteurella multocida（Pm）が検出されたが，発熱供試牛（発熱牛）では全頭からMannheimia haemolytica（Mh），Pm あるいはHistophilus somni のいずれかが分離された．2014年の8頭による調査では，対照牛の1頭のみからPm を検出し，発熱牛からはMh，Pm を検出した．全供試牛からMycoplasma 属菌は検出されなかった．これらの知見は，導入後に発熱を呈する牛の気管支肺胞領域に肺炎原因菌が存在することを示しており，治療指針の決定に重要であると考えられた．