Assessment of genetic variation for pathogen-specific mastitis resistance in Valle del Belice dairy sheep

Abstract

BackgroundMastitis resistance is a complex and multifactorial trait, and its expression depends on both genetic and environmental factors, including infection pressure. The objective of this research was to determine the genetic basis of mastitis resistance to specific pathogens using a repeatability threshold probit animal model.ResultsThe most prevalent isolated pathogens were coagulase-negative staphylococci (CNS); 39 % of records and 77 % of the animals infected at least one time in the whole period of study. There was significant genetic variation only for Streptococci (STR). In addition, there was a positive genetic correlation between STR and all pathogens together (ALL) (0.36 ± 0.22), and CNS and ALL (0.92 ± 0.04).ConclusionThe results of our study support the presence of significant genetic variation for mastitis caused by Streptococci and suggest the importance of discriminating between different pathogens causing mastitis due to the fact that they most likely influence different genetic traits. Low heritabilities for pathogen specific-mastitis resistance may be considered when including bacteriological status as a measure of mastitis presence to implement breeding strategies for improving udder health in dairy ewes.

Study on prevalence, clinical presentation, and associated bacterial pathogens of goat mastitis in Bauchi, Plateau, and Edo states, Nigeria

“…Mastitis is a major cause of substantial economic losses in dairy goat's flocks. Economic losses are due to decreased milk yield, changes in milk quality and composition, increased cost of treatment, increased mortality of kids, and potentially premature culling of small ruminants [11,12].…”

The genomic architecture of mastitis resistance in dairy sheep

“…The susceptibility of dairy animals to udder infection is heritable [ 2 , 7 – 9 ] but the current knowledge of the complex physiological and cellular events that occur in the mammary gland in response to pathogens is limited. In cattle, the common mastitis pathogens , Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ), activate the mammary immune system in different ways, influencing disease severity and chronicity [ 10 ].…”

Relationship between Somatic Cell Score and Fat Plus Protein Yield in the First Three Lactations in Spanish Florida Goats

“…The positive results published in Holstein cattle in the USA and Canada [20], with reductions ranging from around 10% to 40% in SCC levels, have provided very encouraging support for work in small ruminants. Results in dairy goats (Scholtens et al [15] in New Zealand breeds; Arnal et al [21] in French Alpine goats) and dairy sheep (Serrano et al [22] in the Manchega breed; Riggio et al [23]; Tolone et al [24] in the Valle del Belice breed) also point in the same direction. The usefulness of recording and analyzing SCC has the major advantage that it is a very simple character which can be incorporated in bulk into the periodic dairy control systems in these species.…”