Influence of digital dermatitis and sole ulcer on dairy cow behaviour and milk production.

The aim of the study was to investigate whether the presence of digital dermatitis (DD) and sole ulcer (SU) in dairy cows was associated with changes in behaviour and milk production. Swedish Red and Swedish Holstein cows (mostly in the first to second lactation) were housed in a cubicle system with automatically scraped passageways. After maintenance claw trimming of all the cows in the herd, 10 cows with DD and 10 cows with SU were selected. For each DD- or SU-affected cow, a healthy control cow, matched according to breed, age, parity and lactation stage, was selected. The behaviour of each of the 20 focal cows was observed for 1 h during 2 to 3 weeks after claw trimming (WACT; period 1) and for 1 h during 5 to 6 WACT (period 2). Milk production parameters: energy-corrected milk (ECM), fat and protein percentages and somatic cell counts (SCCs) were recorded once monthly. Lameness was scored once at the start of the study and cows with SU and DD showed more score 2 lameness (42% v. 31%) than the healthy cows (12%). Most differences in behaviour were found during 2 to 3 WACT when DD- and SU-affected cows were lying less (P = 0.001 and P = 0.012, respectively) than healthy cows. Ruminating while standing was performed more in DD-affected cows (P < 0.001) and tended to be performed more in SU-affected cows (P = 0.079) than their controls. Vigilance was performed more in DD- and SU-affected cows than in healthy cows (P < 0.001 and P = 0.047). Cows with DD produced approximately 5.5 kg less ECM per day both at 2 to 3 WACT (P = 0.022) and at 5 to 6 WACT (P = 0.017) than healthy cows, whereas SU-affected cows tended to produce less ECM at 5 to 6 WACT (P = 0.059). No differences in milk fat and protein or SCC were found. It may be concluded that DD-affected cows showed a stronger behavioural response to the claw disease than the SU-affected cows. This shows the importance of regular claw checking and claw trimming of the cows in order to avoid the negative effects on behaviour and milk production.

Survival of salmonellas in urine and dry faeces from cattle--an experimental study.

In order to contribute to the understanding of Salmonella transmission via animal excretes the survival of Salmonellas in cattle urine and in dry cow faeces was studied. It was shown that in urine, separated in the gutter without active mixing with faeces, Salmonella did not survive more than 5 days. In dry cow faeces on different stall surfaces Salmonella Dublin were found to survive for almost 6 years on the 4 tested surface materials.

A disease monitoring system for dairy herds.

A system for recording and evaluating disease, intended for both dairy herd health monitoring and research purposes, is described. The system was initiated in 1960 with the objective of providing a research database and it has been developed to respond to the herd health management needs of modern farmers and veterinarians. The system is probably one of the oldest disease recording systems in existence and has contributed to the expansion of epidemiological knowledge of dairy cattle diseases and has helped to improve the health management of dairy herds. The history of the system, the herd reporting form and various analyses and reports generated with the system are presented.

Epidemiological study of clinical mastitis in dairy cattle.

The incidence rate of clinical mastitis in primiparous Swedish Friesian cows was 15%. The risk of mastitis was greater for calving in July and August and increased with age at calving. Calving disorders and ketosis increased the risk of mastitis 1.8 and 2 fold, while tramped teats and udder injuries increased it 6 and 3 fold, respectively. Herds accounted for 13% of the variation in incidence of mastitis and the risk of mastitis was 1.4 and 1.25 fold greater in high and average producing herds relative to low producing herds. High production predisposed cows for mastitis. Cows with clinical mastitis produced 260 kg less milk and were 2.8 fold more likely to be culled.

Survival of Salmonellas in composted and not composted solid animal manure.

Survival of S. dublin, S. senftenberg and S. typhimurium in composted cattle manure was less than seven days. In cold cattle manures S. dublin survived 183 days but not 190, while S. senftenberg and S. typhimurium survived 204 but not 214 days. In composted sow manure S. senftenberg and S. typhimurium survived less than seven days while S. derby survived 14 days but not 21.

Tramped teats--clinical mastitis disease complex in tied cows. Environmental risk factors and interrelationships with other diseases.

The effects of stall length, manure system, type of bedding and calving disorders on incidence rates of tramped teats, udder injuries, and clinical mastitis in Swedish Red and White tied cows, as well as interrelationships between these 3 disorders were investigated. Data used consisted of 370 herds, for a total of 45,133 cow records. Cows in herds with liquid manure system were at higher risk of udder injuries and mastitis than in herds with solid system. Lower risk of both udder injuries and mastitis was found for cows in herds with short stall size (less than 180 cm) compared to herds with stalls of 205-219 cm length. It was suggested that other factors, such as slipperiness of the stall floor and presence and type of feeding barrier, must be considered when the effect of stall characteristics on tramped teats is investigated. In farms with solid manure system cut straw or sawdust bedding increased the risk of tramped teats and mastitis relative to uncut straw. Parity and calving disorders were important risk factors for udder health and their effect was greater in herds with liquid manure system. Tramped teats and udder injuries were the most serious risk factors for clinical mastitis.