High Milk Somatic Cell Counts and Increased Teladorsagia Burdens Overshadow Non-Infection-Related Factors as Predictors of Fat and Protein Content of Bulk-Tank Raw Milk in Sheep and Goat Farms

Abstract

This paper presents the results of an extensive countrywide investigation performed in 325 dairy sheep flocks and 119 goat herds throughout Greece. The objectives of the study were (a) to investigate fat and protein content in the bulk-tank raw milk of small ruminant farms in Greece and (b) to identify factors potentially influencing that content and factors that can contribute to increased content. The mean fat/protein contents in bulk-tank raw milk of sheep and goats were 6.16 ± 0.05%/4.43 ± 0.01% and 4.77 ± 0.44%/3.23 ± 0.30%, respectively. Significant differences were seen in protein content between farms in the various parts of the country. For sheep, multivariable analyses revealed breed and age of lamb removal from dams as significant for fat content, and somatic cell counts, management system in the farm, administration of anthelmintic treatment during the last stage of pregnancy, and farmer education as significant for protein content. For goats, significant factors were month into lactation period, age of kid removal from dams, and breed for fat content, and somatic cell counts, month into lactation, grazing duration, and % Teladorsagia larvae in faecal samples for protein content. For concurrently high fat and protein content, in multivariable analyses, the following emerged as significant factors: somatic cell counts in milk, numbers of parasite eggs in faeces, and veterinary collaboration (sheep), and month into lactation and somatic cell counts in milk (goats). The results indicate that high somatic cell counts in milk (reflecting the presence of mastitis) and gastrointestinal parasitic infections (mainly Teladorsagia infection) appear to exert a more significant influence on fat and protein content of milk, in comparison to non-infection-related factors.

Use of Antibiotics against Bacterial Infections on Dairy Sheep and Goat Farms: Patterns of Usage and Associations with Health Management and Human Resources

“…Before laboratory analysis, two 10 mL subsamples were created and processed; therefore, each separate test was performed four times (each one in different subsamples). Milk composition and somatic cell counting were performed within 4 h after collection on each of the four relevant subsamples, as previously detailed [ 9 , 10 , 11 ]. Moreover, milk samples were processed for total bacterial counts, and culturing was performed for isolation and identification of staphylococcal species as described previously [ 9 , 10 , 11 ].…”

“…The analysis results for the two subsamples from each of the two milk samples collected from the bulk tank were averaged, then the two means were again averaged for the final result regarding each bulk-tank milk. For statistical analysis, the somatic cell counts were transformed to somatic cell scores and the total bacterial counts were transformed to log 10 as described previously [ 9 , 10 , 11 ]; the transformed data were used in the analyses. Differences were determined by using analysis of variance.…”

Helminth Infections in Dairy Sheep Found in an Extensive Countrywide Study in Greece and Potential Predictors for Their Presence in Faecal Samples

“…For epg counts, the value of 300 epg was defined, because in previous studies it had been considered as the threshold above which anthelmintic treatments should be performed [ 18 ] and was also found to be associated with the increased prevalence of subclinical mastitis [ 7 ] in dairy sheep in Greece. For the proportion of Teladorsagia spp., the threshold (63%) was defined, because in a recent study it emerged as a predictor affecting the composition of milk in dairy sheep [ 5 ]. Finally, for the proportion of H. contortus , the threshold (29%) was defined as the average proportion of the helminth in samples from all the untreated flocks in the present study.…”

“…In dairy sheep production systems, previous publications have reported that gastrointestinal nematode parasitism can cause from 10 to 15% reduction in the milk yield of affected ewes [ 3 , 4 ]. Moreover, helminth infections have been found to be associated with reduced fat and protein contents in milk [ 4 , 5 ]. Additionally, these infections have been considered as potential risk factors for mastitis in ewes, as found in field (for trematodes [ 6 ] and nematodes [ 7 ]) or in experimental [ 8 ] studies [ 9 ].…”

Patterns of Reproductive Management in Sheep and Goat Farms in Greece

“…During the visits in the farms, samples of bulk tank milk were collected for somatic cell counts, total bacterial counts and milk composition measurement. Full details of the collection and the processing of samples have been presented before [ 9 ].…”