Observations sur l'emploi de différents produits de nettoyage et de désinfection des machines à traire

Abstract - Five dairy sanitizers have been used for the cleaning of milking machines in the practical conditions of the cowshed, during a period of 6 months: one quaternary ammonium compound, one organic chlorine compound, one phenolic compound and two hypochlorite compounds (containing 100 and 200 p.p.m. available chlorine. The cleaning solutions were circulated through the clusters using an " auto-washer ". For comparison, one milking unit was cleaned by immersion in a 2 p. 100 caustic soda solution and another by rinsing with hot water (80° C). New teat liners made of G.R.S. + Perbunan rubber were used for the experiment.
The cleaning efficiency of the various solutions was assessed by the pulsator-vacuum technique and by estimating the total bacterial count in the rinses, using previously defined bacteriological standards. The corrosive action of the cleaning solutions on the rubber was observed by microscopical examination of the inner surface of the teat liners and by elasticity measurements. A scale of notation was used for judging the deterioration of the rubber surface.
The best bacteriological results were obtained when the liners were cleaned with hot water only. The inner surface of the liners was satisfactory, but the modulus of elasticity was notably decreased after 6 months of use.
The caustic soda immersion technique gave satisfactory results during the whole period of the experiment, but the liners became cracked, with a low modulus of elasticity.
Good bacteriological results were obtained with the quaternary ammonium compound, however, a mineral deposit was observed on the surface of the equipment and the liners were cracked.
The phenolic compound solution gave satisfactory results during the whole period of the experiment. The inner surface of the liners was undamaged, but the modulus of elasticity was low.
The bacteriological results were also satisfactory with the organic chlorine compound. The inner surface of the liners had slightly deteriorated but the modulus of elasticity of the rubber was similar to that of the control.
The solutions containing hypochlorite gave satisfactory results only at the beginning of the experiment. After 4 or 5 months of use, the inner surface of the rubber was cracked and the bacteriological results were no longer satisfactory

Résumé - Différents produits de nettoyage des machines à traire, à la fois détersifs et bactéricides, ont été comparés dans les conditions normales d'utilisation à l'étable, du point de vue de leur efficacité désinfectante et de leur action sur le caoutchouc des manchons-trayeurs.
Les résultats bactériologiques obtenus sont généralement satisfaisants avec toutes les solutions de nettoyage. Cependant, après 4 à 5 mois d'utilisation, les manchons-trayeurs nettoyés avec les solutions contenant de l'hypochlorite se trouvent nettement corrodés. Dans ce cas les résultats cessent d'être satisfaisants.
Des mesures d'élasticité effectuées sur les manchons-trayeurs après 6 mois d'utilisation montrent une diminution notable du module d'élasticité du caoutchouc des manchons nettoyés avec plusieurs des produits utilisés