Effects of intramammary infusion of Bifidobacterium breve on mastitis pathogens and somatic cell response in quarters from dairy cows with chronic subclinical mastitis

The present study assessed the effects of intramammary infusion of Bifidobacterium breve (B. breve) on mastitis‐causing pathogens and on the somatic cell counts (SCC) in lactating cows with chronic subclinical mastitis. The bacteriological cure rates of 42 quarters from 42 cows infected with Staphylococcus aureus, Corynebacterium bovis, coagulase‐negative staphylococci, and environmental streptococci were 18.2% (2/11), 14.3% (1/7), 58.8% (10/17), and 28.6% (2/7), respectively, on day 14 after B. breve infusion. In a second trial, B. breve was infused into 18 quarters from 18 cows with chronic subclinical mastitis from which pathogens had not been isolated; the rates of quarters showing SCC > 50 × 10⁴ cells/ml prior to B. breve infusion that decreased to < 30 × 10⁴ cells/ml after infusion were significantly (p < .01) increased to 61.1% (11/18) on day 14 compared to that prior to infusion (0/18). The intramammary infusion of B. breve appears to be a non‐antibiotic approach for elimination of minor pathogens and decreasing SCC in quarters with chronic subclinical mastitis in dairy cows.     

Urbanization and its implications for avian aggression: a case study of urban black kites (Milvus migrans) along Sagami Bay in Japan

Urbanization has caused countless changes in the lives, behaviors, and community structures of wild animals. Habitat loss in urban areas has led to the proliferation of certain species over others; in the case of birds, frugivores and certain predators can be found in abundance in cities. These birds, however, occasionally show novel behaviors that can cause stress within human-wildlife interactions. The black kite, Milvus migrans, for example, has displayed a tendency to attack humans for their food in certain urban areas in Japan. In order to determine how habitat availability and land-use types affected these aggressive tendencies, field observations were combined with GIS analysis of five locations along Sagami Bay in Japan. The following locations were assessed according to the amount of each land-use type present and the aggressive tendencies of each location’s black kite population: Enoshima, Fujisawa; Kamakura Beach, Kamakura; Zushi Beach, Zushi; Oiso Beach, Oiso; and Iwa Beach, Manazuru. The aggression of each population, designated by the log of the aggression index, was found to be significantly affected by the amount of forest area per black kite, the amount of non-rice-paddy agricultural area per black kite, and the season. Thus, aggression was higher amongst populations with less forested or agricultural area within their foraging zones, and aggression increased during spring, which is the breeding season.     

A simplified PCR assay for fast and easy mycoplasma mastitis screening in dairy cattle

A simplified polymerase chain reaction (PCR) assay was developed for fast and easy screening of mycoplasma mastitis in dairy cattle. Species of major mycoplasma strains [Mycoplasma (M.) bovis, M. arginini, M. bovigenitalium, M. californicum, M. bovirhinis, M. alkalescens and M. canadense] in cultured milk samples were detected by this simplified PCR-based method as well as a standard PCR technique. The minimum concentration limit for detecting mycoplasma by the simplified PCR was estimated to be about 2.5 × 10³ cfu/mL and was similar to that of the standard PCR. We compared the specificity and sensitivity of the simplified PCR to those of a culture method. Out of 1,685 milk samples cultured in mycoplasma broth, the simplified PCR detected Mycoplasma DNA in 152 that were also positive according to the culture assay. The sensitivity and specificity of the simplified PCR were 98.7% and 99.7%, respectively, for detecting mycoplasma in those cultures. The results obtained by the simplified PCR were consistent with ones from standard PCR. This newly developed simplified PCR, which does not require DNA purification, can analyze about 300 cultured samples within 3 h. The results from our study suggest that the simplified PCR can be used for mycoplasma mastitis screening in large-scale dairy farms.     

Effect of cashew nut shell liquid on metabolic hydrogen flow on bovine rumen fermentation

Effect of cashew nut shell liquid (CNSL), a methane inhibitor, on bovine rumen fermentation was investigated through analysis of the metabolic hydrogen flow estimated from concentrations of short‐chain fatty acids (SCFA) and methane. Three cows were fed a concentrate and hay diet without or with a CNSL‐containing pellet. Two trials were conducted using CNSL pellets blended with only silica (trial 1) or with several other ingredients (trial 2). Methane production was measured in a respiration chamber system, and energy balance and nutrient digestibility were monitored. The estimated flow of metabolic hydrogen demonstrated that a part of metabolic hydrogen was used for hydrogen gas production, and a large amount of it flowed into production of methane and SCFA in both trial 1 and 2, when CNSL was administered to the bovine rumen. The results obtained by regression analyses showed that the effect of CNSL supply on methane reduction was coupled with a significant (P < 0.01) decrease of acetate and a significant (P < 0.01) increase of propionate and hydrogen gas. These findings reveal that CNSL is able to reduce methane and acetate production, and to increase hydrogen gas and propionate production in vivo.     

Polymerase chain reaction-based identity assay for pathogenic turkey Eimeria

Diagnosis of turkey Eimeria infection by conventional parasitologic methods is challenging and, until now, no molecular tools existed that clearly distinguished the four widely recognized pathogenic species: Eimeria adenoeides, E. meleagrimitis, E. gallopavonis, and E. dispersa. In this study, the internal transcribed spacer region one (ITS-1) was amplified and sequenced from 23 conventionally characterized reference samples. Phylogenic analysis segregated samples into five distinct cluster groups. The ITS-1 region(s) within each cluster were of a particular length and shared from 96% to 100% identity, while amplified ITS-1 region(s) between clusters differed in length and shared only 10.6% to 49.7% sequence identity. In addition, we developed PCR primer sets as diagnostic tools capable of specifically identifying members of each of the five clusters.     

Relationship between the temperature and the overwintering of water lettuce (Pistia stratiotes) at Kowataike,a branch of Yodogawa River,Japan

The successful overwintering of water lettuce (Araceae, Pistia stratiotes L.) is reported in Kowataike, a pond in Kyoto Prefecture, Japan, in the temperate climate zone. Overwintering was observed in the northern zone of Kowataike, where warm water discharge flows from an upstream electrical appliance factory. From December 2007 to January 2008, several overwintering water lettuce plants were observed in the northern zone where the water temperature was abnormally high (average: 21.9°C; low: 19.5°C). Water in the central zone of Kowataike was isolated from the warm water discharge. The temperatures here were much lower (average: 8.2°C; low: 4.2°C) and no water lettuce plant survived here. The overwintering in the northern zone fluctuated annually. This fluctuation appeared to be correlated with the period of warm water discharge, which varied from year to year and resulted in higher water temperatures most, but not all, of the winter. The results suggest that artificial environmental factors, such as anthropogenic warm water discharge, could enable water lettuce to overwinter. In the northern zone of Kowataike under the influence of the warm water discharge, only small water lettuce plants overwintered. This may be attributed to the presence of older plants with larger leaves that seemed to protect the small rosettes from frost. Second, the air warmed by the warm discharge accumulated in the space under the piles of dead large leaves, which created conditions similar to those of a greenhouse. These two mechanisms apparently allow the small water lettuce plants to be surrounded by moderate atmospheric conditions.