Mammary Pathogens and Their Relationship to Somatic Cell Count and Milk Yield Losses in Dairy Ewes

Abstract. The aim of this study was to determine the effect of somatic cell count (SCC) on milk yield and composition using a threshold value of 250 ∙103 cells/ml in dairy ewes of line 05. A total of 1 512 milk samples from udder halves were collected throughout milking periods at monthly intervals. In the present study milk composition (from halves of the udder) and daily milk yield (from udders) was examined in terms of SCC in ewe milk in three groups: from both halves of the udder below 250 ∙103 cells/ml, from one halves of the udder below 250 ∙103 cells/ml and from second half udder above 250 ∙103 cells/ml and from both halves of the udder above 250 ∙103 cells/ml. Milk yield from udders, somatic cell count in milk samples from udder halves and milk composition depended on the level of SCC recorded for halves of the udder. Somatic cell counts in milk from one or both halves of udders exceeding 250 ∙103 cells/ ml resulted in a statistically significant (P<0.01) decrease in daily milk production of ewes, by approx. 15.89 and 30.22 %, respectively. The analysis of variance showed also a significant effect of parity and stage of lactation of ewes on somatic cell count (log SCC) and milk composition from udder halves below 250 ∙103 cells/ml.

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Daily and between-milking variations and repeatabilities in milk yield, somatic cell count, fat, and protein of dairy ewes

Small Ruminant Research ◽

10.1016/s0921-4488(96)00927-3 ◽

1997 ◽

Vol 24 (2) ◽

pp. 133-139 ◽

Cited By ~ 10

Author(s):

L.F. de la Fuente ◽

F.San Primitivo ◽

J.A. Fuertes ◽

C. Gonzalo

Keyword(s):

Somatic Cell ◽

Cell Count ◽

Milk Yield ◽

Somatic Cell Count ◽

Dairy Ewes

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A new somatic cell count index to more accurately predict milk yield losses

Archives Animal Breeding ◽

10.5194/aab-60-373-2017 ◽

2017 ◽

Vol 60 (4) ◽

pp. 373-383 ◽

Cited By ~ 4

Author(s):

Janez Jeretina ◽

Dejan Škorjanc ◽

Drago Babnik

Keyword(s):

Somatic Cell ◽

Cell Count ◽

Milk Yield ◽

Somatic Cell Count ◽

Yield Loss ◽

Early Stage ◽

Economic Losses ◽

Yield Losses ◽

Daily Milk Yield ◽

Daily Milk

Abstract. Intramammary infection and clinical mastitis in dairy cows leads to considerable economic losses for farmers. The somatic cell concentration in cow's milk has been shown to be an excellent indicator for the prevalence of subclinical mastitis. In this study, a new somatic cell count index (SCCI) was proposed for the accurate prediction of milk yield losses caused by elevated somatic cell count (SCC). In all, 97 238 lactations (55 207 Holstein cows) from 2328 herds were recorded between 2010 and 2014 under different scenarios (high and low levels of SCC, four lactation stages, different milk yield intensities, and parities (1, 2, and ≥  3). The standard shape of the curve for SCC was determined using completed standard lactations of healthy cows. The SCCI was defined as the sum of the differences between the measured interpolated values of the natural logarithm of SCC (ln(SCC)) and the values for the standard shape of the curve for SCC for a particular period, divided by the total area enclosed by the standard curve and upper limit of ln(SCC)  =  10 for SCC. The phenotypic potential of milk yield (305-day milk yield – MY305) was calculated using regression coefficients estimated from the linear regression model for parity and breeding values of cows for milk yield. The extent of daily milk yield loss caused by increased SCC was found to be mainly related to the early stage of lactation. Depending on the possible scenarios, the estimated milk yield loss from MY305 for primiparous cows was at least 0.8 to 0.9 kg day−1 and for multiparous cows it ranged from 1.3 to 4.3 kg day−1. Thus, the SCCI was a suitable indicator for estimating daily milk yield losses associated with increased SCC and might provide farmers reliable information to take appropriate measures for ensuring good health of cows and reducing milk yield losses at the herd level.

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Effect of Palpable Udder Defects on Milk Yield, Somatic Cell Count, and Milk Composition in Non-Dairy Ewes

Animals ◽

10.3390/ani11102831 ◽

2021 ◽

Vol 11 (10) ◽

pp. 2831

Author(s):

Mandefrot M. Zeleke ◽

Paul R. Kenyon ◽

Kate J. Flay ◽

Danielle Aberdein ◽

Sarah J. Pain ◽

...

Keyword(s):

Somatic Cell ◽

Cell Count ◽

Milk Yield ◽

Defect Detection ◽

Mixed Models ◽

Somatic Cell Count ◽

Potential Effect ◽

Milk Composition ◽

Dairy Ewes ◽

History Of

In non-dairy ewes, udder defects hinder the survival and weight gain of their pre-weaned lambs. The objectives of this study were to determine the effects of palpable udder defects on milk yield, somatic cell count (SCC), and milk composition in non-dairy Romney ewes. Ewes with a history of udder defects or normal udders were selected for the study. Of a total of 48 ewes that lambed, 30 ewes reared at least one lamb, and were milked six times, once weekly, for the first six weeks of lactation. Udder halves were palpated and scored at each milking event. Multivariate linear mixed models examined the impacts of udder defects on udder-half and whole-udder milk yield, SCC, and milk composition (fat, protein, lactose, total solids, and solids non-fat (SNF)). Across the six examinations, 24.7% of the total 352 udder-half examinations were observed to be defective. Udder halves that were defective at least once produced on average 57.9% less (p < 0.05) milk than normal udder halves, while normal udder halves with a contralateral defective half yielded 33.5% more (p < 0.05) milk than normal udder halves. Successive occurrence of both hard and lump udder defect categories in an udder-half, udder defect detection early in lactation, and a high frequency of udder defect detection were all associated with udder-half milk yield loss (p < 0.05). At the whole-udder level, no differences in milk yield (p > 0.05) were observed between those with one udder-half defective and both normal udder-halves. However, udders in which one udder half was categorised as hard but progressed to lump and remained as lump until 42 days of lactation produced less (p < 0.05) milk compared with normal udders. With the exception of SNF, there were no significant associations (p > 0.05) between milk composition parameters and udder defect. Overall, these findings emphasise the importance of udder health in non-dairy ewes and the potential effect of udder defects on their lambs.

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Milk yield, milk composition and somatic cell count of dairy goats given n-3 unsaturated fatty acids diet supplement

Acta veterinaria ◽

10.2298/avb1203281g ◽

2012 ◽

Vol 62 (2-3) ◽

pp. 281-287

Author(s):

Vesna Gantner ◽

D. Kompan

Keyword(s):

Fatty Acids ◽

Somatic Cell ◽

Cell Count ◽

Milk Yield ◽

Somatic Cell Count ◽

Unsaturated Fatty Acids ◽

Milk Composition ◽

Dairy Goats ◽

Diet Supplement

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Hyperketonemia Predictions Provide an On-Farm Management Tool with Epidemiological Insights

Animals ◽

10.3390/ani11051291 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1291

Author(s):

Ryan S. Pralle ◽

Joel D. Amdall ◽

Robert H. Fourdraine ◽

Garrett R. Oetzel ◽

Heather M. White

Keyword(s):

Somatic Cell ◽

Cell Count ◽

Milk Yield ◽

Milk Fat ◽

Somatic Cell Count ◽

Past Research ◽

Management Tool ◽

Milk Analysis ◽

Linear Regression Models ◽

High Throughput Detection

Prediction of hyperketonemia (HYK), a postpartum metabolic disorder in dairy cows, through use of cow and milk data has allowed for high-throughput detection and monitoring during monthly milk sampling. The objective of this study was to determine associations between predicted HYK (pHYK) and production parameters in a dataset generated from routine milk analysis samples. Data from 240,714 lactations across 335 farms were analyzed with multiple linear regression models to determine HYK status. Data on HYK or disease treatment was not solicited. Consistent with past research, pHYK cows had greater previous lactation dry period length, somatic cell count, and dystocia. Cows identified as pHYK had lower milk yield and protein percent but greater milk fat, specifically greater mixed and preformed fatty acids (FA), and greater somatic cell count (SCC). Differential somatic cell count was greater in second and fourth parity pHYK cows. Culling (60d), days open, and number of artificial inseminations were greater in pHYK cows. Hyperketonemia prevalence decreased linearly in herds with greater rolling herd average milk yield. This research confirms previously identified risk factors and negative outcomes associated with pHYK and highlights novel associations with differential SCC, mixed FA, and preformed FA across farm sizes and production levels.

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