Mastitis is an inflammation of the mammary gland initiated by pathogenic bacteria. In fact, mastitis is the second most important reason for the culling of cows from dairy herds, after infertility. In this review we focus on various forms of mastitis, including subclinical and clinical mastitis. We also stress the importance of the dry-off period as an important time when pathogenic bacteria might start their insult to the mammary gland. An important part of the review is the negative effects of mastitis on milk production and composition, as well as economic consequences for dairy farms. The two most important groups of bacteria that are involved in infection of the udder, Gram-negative and Gram-positive bacteria, are also discussed. Although all cows have both innate and adaptive immunity against most pathogens, some are more susceptible to the disease than others. That’s why we summarize the most important components of innate and adaptive immunity so that the reader understands the specific immune responses of the udder to pathogenic bacteria. One of the most important sections of this review is interrelationship of mastitis with other diseases, especially retained placenta, metritis and endometritis, ketosis, and laminitis. Is mastitis the cause or the consequence of this disease? Finally, the review concludes with treatment and preventive approaches to mastitis.

Intramammary infections (mastitis) of dairy cows, along with other periparturient diseases, have become problematic within the dairy industry as they lead to loss of milk production. The main objective of this study was to determine whether elevated somatic cell counts (SCC) in cows prior to drying off are related to the incidence of other periparturient diseases. Additionally, we de-termined whether milk composition and milk yield are affected by a high SCC prior to drying off. Somatic cell counts of milk samples were determined prior to dry off (n = 140) and were used to classify cows in the study as high (>200,000 cells/mL) or low (<200,000 cells/mL) SCC. The com-position of milk was analyzed before drying off and at 1 and 2 weeks after calving. The results showed that an elevated SCC before drying off was related to the incidence of ketosis. Cows with a high SCC at drying off also showed an increased likelihood of retained placenta, metritis, and lameness postpartum; however, it was not statistically significant. Milk lactose was lower in cows with high SCC, while protein content was lower after parturition. Milk production was lower for cows with pre-drying elevated SCC, particularly for cows with retained placenta, keto-sis, and mastitis. In conclusion, cows with pre-drying elevated SCC were more likely to develop disease after parturition and produce less milk and with lower lactose and protein content.

Galectins constitute an evolutionarily conserved family of β-galactoside-binding proteins. They regulate innate and adaptive immunity and homeostasis. Expression of Galectins may regulate periparturient immune suppression. Galectin gene expression was studied in goat blood during the periparturient period. Body weight, body condition and FAMACHA scores, and fecal and blood samples were collected from Five BoerXSpanish goats at 14 days and 7 days after parturition. Fecal samples were used to assess parasite load. Total RNA was isolated from blood using Trizol and converted to cDNA for real-time PCR using specific primers for goat LGALs-1, -2, -3, -4, -7, -8, -9, -11, -12, -14, -15, -16, and ligand Gal3bp, T-cell immunoglobulin domain, and mucin domain 3(TIM-3). Beta-actin and GAPDH housekeeping genes were used as internal controls. Fold changes in transcript abundance were compared to non-pregnant goats and calculated using the Livak method. Secretion of GALS-1, -3 and -9 in plasma was detected using ELISA. Data were analyzed using SAS 9.4 and Pearson correlations (p<0.05). Galectins were expressed and correlated to changes in leukocytes and fecal egg counts. Secreted GALS-1 decreased and GALS-3 and -9 increased (p<0.05) postpartum. Differential expression of Gal may have functional implications in animal health and homeostasis and needs further study.