Potential Novel Biomarkers for Mastitis Diagnosis in Sheep

Abstract

This review aims to characterize promising novel markers of ovine mastitis. Mastitis is considered as one of the primary factors for premature culling in dairy sheep and has noticeable financial, productional, and animal welfare-related implications. Furthermore, clinical, and subclinical mammary infections negatively affect milk yield and alter the milk composition, thereby leading to lowered quality of dairy products. It is, therefore, crucial to control and prevent mastitis through proper diagnosis, treatment or culling, and appropriate udder health management particularly at the end of the lactation period. The clinical form of mastitis is characterized by abnormalities in milk and mammary gland tissue alteration or systemic symptoms consequently causing minor diagnostic difficulties. However, to identify ewes with subclinical mastitis, laboratory diagnostics is crucial. Mastitis control is primarily dependent on determining somatic cell count (SCC) and the California Mastitis Test (CMT), which aim to detect the quantity of cells in the milk sample. The other useful diagnostic tool is microbial culture, which complements SCC and CMT. However, all mentioned diagnostic methods have their limitations and therefore novel biomarkers of ovine subclinical mastitis are highly desired. These sensitive indicators include acute-phase proteins, miRNA, and cathelicidins measurements, which could be determined in ovine serum and/or milk and in the future may become useful in early mastitis diagnostics as well as a preventive tool. This may contribute to increased detection of ovine mammary gland inflammation in sheep, especially in subclinical form, and consequently improves milk quality and quantity.

Clinicopathological study on camel mastitis at Matrouh Governorate

“…This study demonstrated a marked increase in APPs (Fb, Cp, SAA, and Hp) concentrations in CMG. Similar observations were reported before for mastitis in camels and other animal species [ 15 , 19 – 21 ]. Additionally, the pro-inflammatory cytokines prompt free radicals liberation from different immune cells.…”

Effects of Dietary Omega-3 Enrichment on the Chemical Composition and the Pathogenic Microbiota of Ovine Milk

“…Veillonella parvula is not able to ferment carbohydrates and lives on the lactate produced by Streptococci [ 81 , 82 ], so it is reasonable to assume that this bacterium was rather isolated due to the isolation of the aforementioned Streptococci. Finally, the two Enterobacteriaceae species ( Enterobacter cloacae and Enterobacter kobei ), although pathogenic for the respiratory tract, are considered major pathogens for the mammary gland [ 83 , 84 ]. All these findings suggest a semi-protective effect of the dietary omega-3 fatty acids on bacterial populations in the udder.…”

Age-Related Changes in Acute Phase Reaction, Cortisol, and Haematological Parameters in Ewes in the Periparturient Period

“…Higher concentrations of these proteins, determined in the last phase of pregnancy and after calving, may relate to the changing hormone profile (the influence of oestrogens and progesterone) [ 10 , 20 ]. The physiological role of SAA is the inhibition of lymphocyte proliferation, oxidative reactions in neutrophils, and platelet and thrombocyte aggregation and detoxification of endotoxins [ 29 ]. Fibrinogen binds specifically to the CD11/CD18 receptors on the migrated phagocytes’ surface and releases a cascade of intracellular signals that lead to increased phagocytosis, degranulation, and antibody-dependent cellular cytotoxicity and apoptosis [ 29 ].…”