Abstract
ABSTRACT. Zafalon L.F., Martins K.B., Dias W.A.F., Veríssimo C.J., Esteves S.N. & Veschi J.L.A. [Effects of infectious subclinical mastitis on the performance of lambs in Santa Ines breed]. Efeitos da mastite subclínica infecciosa sobre o desempenho de cordeiros na raça Santa Inês. Revista Brasileira de Medicina Veterinária 35(4):299-305, 2013. Empresa Brasileira de Pesquisa Agropecuária, Embrapa Pecuária Sudeste, Rodovia Washington Luís, km 234, Caixa Postal 339, São Carlos, 13560-970, SP Brasil. E-mail: luiz.zafalon@embrapa.br The mastitis is an inflammation of mammary gland, clinical or subclinical, with interference in the composition and quantity of milk secreted by ewe. The objectives were to assess the influence of subclinical mastitis in Santa Inês ewes, the main microorganisms involved in infectious etiology of the disease and the consequences for the somatic cell count and weight gain of lambs. Two hundred and forty ewes and 316 lambs were studied during the period of lactation and at weaning, with weightings of lambs at birth, at second lactation week and at weaning. After first identifying the animals with subclinical mastitis by California Mastitis Test, milk samples from healthy and subclinical mastitis females were obtained and subjected to laboratory testing for microbiological confirmation of the etiology of infectious disease and for somatic cell count of milk. Coagulase negative staphylococci were the most frequent microorganisms and higher somatic cell counts have been described in some of the groups of ewes with subclinical mastitis until the second week of lactation. The subclinical mastitis did not influence significantly the weight gain of lambs from Santa Inês sheep in the production systems evaluation.