458. Clinical mastitis in six herds freed from Streptococcus agalactiae

Abstract

The difficulty of keeping herds free from Strep. agalactiae for long periods has been demonstrated in five herds. In one sense, however, these herds were not representative of the majority of herds for they were relatively large and under the same management. Furthermore, if one herd became infected with the streptococcus, there was a real risk of the infection spreading to all herds via the hands of the relief milker, particularly if hand stripping was practised and no special precautions were taken by the relief milker.There is no doubt that herds under the same management should take stringent precautions against the spread of infection between herds.

649. The effect of design of teat-cup liners on mastitis incidence

“…The herd was free of Streptococcus agalactiae infection, and about 62 % of the cases of mastitis were caused by Staphylococcus aureus. These findings were thus much the same as in the Elveden herds (8).…”

“…Previous data (8), when extracted(7), showed that there was very significantly more mastitis in both of two herds when they were milked with a moulded liner than when milked with an extruded liner. The experiment reported below was designed to see if this result could be confirmed under more carefully controlled conditions and when the two liners were used simultaneously on the same udder.…”

“…A high incidence of mastitis in dairy herds has been said to be associated with some types of moulded teat-cup liner by Leslie & Whittlestone(2,3), Watts (4,5), 6ambrel (6), N.I.R.D. Annual Report(7), Neave, Phillips & Mattick (8), Wilson (9,10) and Parker (li). On the other hand, Ward, Whittlestone, Hopkirk & Filmer(i2), Ward(i3) and Whittlestone (14) could find no difference in the incidence of mastitis in herds using a particularly hard moulded liner compared with herds using liners of a different design.…”

Coagulase Positive Staphylococci From Bulk Milk Supplies Low in Solids‐not‐fat

“…Variations in breed, feedingstuffs and seasonal conditions, together with many other factors, may influence the milk quality. Where coagulase positive staphylococci are present in the udder a condition of sub-clinical mastitis may prevail and this may be responsible for reduction of the solids-not-fat percentage (Crossman, Dodd, Lee & Neave, 1950;Neave, Phillips & Mattick, 1952 ;Schalm & Woods, 1953a). Whether all staphylococci isolated from bulk milk supplies are derived directly from the udder is a matter for speculation.…”

The effect of pre-enrichment on recovery ofStreptococcus agalactiae, Staphylococcus aureusand mycoplasma from bovine milk

“…agalactiae from high CMT milk than from low CMT milk. The reason for this interaction is not known, but it may reflect a reduced ability for pre-enrichment to detect the low concentrations of the bacteria present during early stages of infection (16,18). It was apparent that several other factors may influence the likelihood of isolating either of the three bacteria from bovine milk studied.…”