Control of intramammary infections in goats: impact on somatic cell counts.

Abstract

Udder-half infections were recorded throughout a lactation for 1,060 goats belonging to eight commercial herds. Bacteriological examination from aseptic milk samples and somatic cell counts (SCC) determined by Fossomatic cell counting were performed at the beginning, the middle, and the end of lactation. Coagulase-negative staphylococci (CNS) were the prevalent microorganisms isolated. Geometric means of SCC for uninfected halves or halves infected by CNS or major pathogens were 272 x 10(3) cells/mL, 932,000 x 10(3) cells/mL and 2,443,000 x 10(3) cells/mL, respectively. Two field trials were carried out for evaluation of effectiveness of systematic treatment at drying-off (1 syringe by half) by a combination of penicillin, nafcillin, and dihydrostreptomycin labeled for bovines. In the first trial, all goats (n = 217) of two herds were treated immediately after the last milking, and two herds (n = 196) were used as untreated controls. In the second trial, 215 goats were treated at drying-off. There were no untreated controls. Dry period cures were determined by bacteriological examination of udder-half milk samples collected aseptically at drying-off and 2 wk after parturition. Impact of treatment on SCC was determined from composite milk samples collected monthly after kidding. At parturition, in the first trial, 40 of 202 (19.8%) udder halves were spontaneously cured in the control group vs 169 of 217 (77.9%) in the treatment group. In the second trial, 141 out of 215 treated halves were cured. During the first 75 d in lactation, geometric mean SCC was significantly lower for treated goats than for control goats. After 75 d, SCC for treated and control goats were similar. These data suggest that other methods are required to prevent new intramammary infections throughout the lactation in order to keep a low SCC in goat milk. To determine whether this could be accomplished through teat dipping, half of the goats in five commercial herds were dipped (n = 294) after morning and evening milkings through the lactation (10 mo) with a teat dip product containing nisin. Undipped goats (n = 292) served as a control group. No difference was found for SCC in milk between the dipped and undipped groups. It was concluded that systematic treatment of goats at drying-off is an efficient method for the cure of subclinical mastitis and control of SCC at the beginning of the following lactation and that effectiveness of postmilking teat disinfection remains to be demonstrated.

Perfil microbiológico, celular e fatores de risco associados à mastite subclínica em cabras no semiárido da Paraíba

“…Nesse estudo, SCN foram as bactérias mais freqüen-tes, concordando com os resultados obtidos anteriormente em outros trabalhos que afirmam que os SCN são os principais agentes isolados na mastite subclínica em caprinos (Mota et al 2000, Muricy 2003. Essas bactérias apresentam importância epidemiológica, pois podem causar mastite subclínica durante toda a lactação ou mesmo no período seco (Poutrel et al 1997), tornando os animais infectados fontes de infecção em potencial no rebanho. Some-se a isso a importância econômica desses agentes, que causam prejuízos aos produtores principalmente devido à redução na produção de leite (Leitner et al 2004).…”

Caracterização da mastite subclínica em caprinos produzidos em sistema orgânico no Rio Grande do Sul

“…Entretanto, apenas 37 (15,6%) apresentaram contagem maior ou igual a 5 UFC/0,01mL de leite (Contreras et al 1996). Staphylococcus coagulase negativo (SCN) foi identificado em 31 (83,8%) amostras, concordando com os resultados de estudos similares conduzidos no Brasil (Mota et al 2000, Muricy 2003) e em outros países (Hunter 1984, Lerondelle & Poutrel 1984, East et al 1987, Ryan & Greenwood 1990, Maisi & Riipinem 1991, Idrissi et al 1994, Contreras et al 1997, Poutrel et al 1997, White & Hinckley 1999, Winter & Baumgartner 1999. O predomínio de SCN poderia ser justificado pela presença destas bactérias na microbiota da pele e conjuntiva dos animais, particularmente no úbere de fêmeas leiteiras (Moroni et al 2005).…”

The effects of dry-off therapy on milk somatic cell count in Saanen goats

“…The dry period is wellacknowledged as being the optimal time to cure existing IMIs (22) as well as being a period of high risk for the acquisition of new IMIs (23,24). Thus, several authors (10,25) concluded that systematic and/or intramammary antibiotic treatment of goats at drying off is an efficient method for the reduction of subclinical mastitis. Poutrel et al (10) recommend systematic treatment when SCC in bulk milk is high (>1.000 × 10 3 cells mL -1 ) and when CoNS are involved in IMI.…”

“…Thus, several authors (10,25) concluded that systematic and/or intramammary antibiotic treatment of goats at drying off is an efficient method for the reduction of subclinical mastitis. Poutrel et al (10) recommend systematic treatment when SCC in bulk milk is high (>1.000 × 10 3 cells mL -1 ) and when CoNS are involved in IMI.…”

“…To improve the health status of the herd, different strategies such as vaccination, milking hygiene, teat dipping, dry-off antibiotic therapy, and teat sealers may be useful (7)(8)(9). It has been stated that dry-off antibiotic therapy is used in dairy goats to control subclinical mastitis and reduce SCC (8,10). Dryoff treatment has the advantage of antibiotics being used when the animal is not being milked, so that there is no milk loss and no antibiotic contamination of the bulktank milk (11).…”