Obesity is an inflammatory state associated with delayed lactogenesis stage II and altered mammary gland morphology. Serotonin mediates inflammation and mammary gland involution. The objective of this study was to determine if a genetic deficiency of tryptophan hydroxylase 1, the rate-limiting enzyme in peripheral serotonin synthesis, would result in an improved ability to lactate in dams fed a...

Female ruminants are susceptible to spontaneous ketosis arising at times of high productive demand. The dairy cow is most susceptible during the first 7 weeks of lactation, whereas the ewe is susceptible, particularly when multifoetate, during the last month of pregnancy. The disorder is characterized by signs of carbohydrate insufficiency and adipose-tissue mobilization. Those of carbohydrate ...

Migration of neutrophils into mammary tissue provides the first immunological line of defense against bacteria that penetrate the physical barrier of the teat canal. Evasion of neutrophil defenses provides an opportunity for invading bacteria to become established. Depletion of neutrophils results in a dramatic increase in susceptibility to intramammary infection. Numerous cytoplasmic particles...

Approximately 88% of Norwegian dairy cattle are housed in tie stalls. Free stall housing for all dairy cattle will be implemented within 20 years. This means that the majority of existing stalls will be rebuilt in the near future. Fifty-seven free stall herds of the Norwegian Red breed were randomly selected and 1547 cows and 403 heifers were trimmed by 13 claw trimmers during the late winter a...

Relationships between somatic cell count (SCC) and variation in milk production at the cow level were reviewed to provide average reference values suitable for the assessment of economic losses due to subclinical mastitis. The literature analysis involved 19 papers, defining milk yield and/or its composition either at test-day level or at the whole lactation level as statistical unit. Within ea...

Knowledge related to udder health in dairy practice is considerably limited. The aim of the experiment was to study the changes of somatic cell counts (SCC) in milk in relation to the month of year, stage of lactation and parity under the practical conditions. Also the frequency of incidence of high SCC during the year was observed. The effectiveness of dry therapy and calving process on SCC wa...