Identification of subclinical mastitis caused by Mycoplasma spp. from screenings of bulk tanks / Identificação de mastite subclínica causada por Mycoplasma spp. de triagem de tanques de expansão

Mastitis caused by Mycoplasma spp., regardless of species, are considered highly contagious pathogens and, usually was not responsive to antimicrobial therapy. Five dairy herds, comprising 489 animals and 1,956 mammary glands, were used in this study. Milk samples were obtained from bulk tanks and subjected to polymerase chain reaction (PCR) for the identification of Mollicutes, Mycoplasma spp., and Mycoplasma bovis. Moreover, individual samples from cases of clinical and subclinical mastitis in quarters of the dairy herds' animals that yielded a positive PCR upon bulk tank analysis were subjected to molecular analysis. Only one bulk tank was positive for class Mollicutes by PCR. All positive samples classified as mastitis teats had their DNA extracted and tested by PCR for both class Mollicutes and M. bovis. Of these, two (2.08%) were positive for Mycoplasma genus, although none was positive for M. bovis. This result suggests that the PCR of bulk tanks is a viable tool in monitoring and preventing mastitis infections caused by Mycoplasma spp.(AU)

Mastites bovinas causadas por Mycoplasma spp., independentemente da espécie causadora, são consideradas de alta contagiosidade e geralmente não responsivas à terapia antimicrobiana. Cinco propriedades leiteiras foram utilizadas neste estudo, totalizando 489 animais e 1956 quartos mamários. As amostras de leite foram obtidas de tanques de expansão e submetidas à reação em cadeia da polimerase (PCR) para pesquisa de Mollicutes, Mycoplasma spp. e Mycoplasma bovis. Apenas um tanque de uma propriedade foi positivo na PCR para a classe Mollicutes. Amostras individuais de casos de mastite subclínica provenientes de propriedade com tanque positivo também foram submetidas à análise molecular; dessas, duas delas (2,08%) foram positivas para a classe Mollicutes e para o gênero Mycoplasma, entretanto nenhuma foi positiva para a espécie Mycoplasma bovis. Isso sugere que a PCR de tanques de expansão de propriedades leiteiras demonstra ser uma ferramenta viável no monitoramento e na prevenção de infecções por Mycoplasma spp.(AU)

Carcass traits and meat quality of Nellore cattle fed different non-fiber carbohydrates sources associated with crude glycerin.

Crude glycerin, a potential energy source for ruminant animals, has been evaluated, mainly, in diets with high starch content. However, a limit number of studies have evaluated the inclusion of crude glycerin in low starch diets. This study aimed to evaluate the effects of the association of crude glycerin with corn grain or citrus pulp on carcass traits and meat quality of Nellore bulls (n=30, 402±31 kg initial weight). The treatment consisted of: CON=control, without crude glycerin; CG10=10% of crude glycerin and corn grain; CG15=15% of crude glycerin and corn grain; CP10=10% of crude glycerin and citrus pulp; CP15=15% of crude glycerin and citrus pulp. The performance parameters and carcass traits were not affected by treatments (P>0.05). The inclusion of crude glycerin decreased yellow color intensity and increased fatty acids pentadecanoic and heptadecenoic in meat (P<0.05), without affecting neither the concentration of polyunsaturated fatty acids nor the relationship of saturated and unsaturated fatty acids. The association of crude glycerin with corn or citrus pulp has no adverse effects on carcass characteristics and meat quality.