Estimating the nonlinear interaction between somatic cell score and differential somatic cell count on milk production by parity using generalized additive models
ABSTRACT: This observational study aimed to use somatic cell score (SCS) and differential somatic cell count (DSCC), the combined proportion of polymorphonuclear leukocytes and lymphocytes in somatic cells, to investigate how mastitis affected milk production. Using generalized additive models, we a...
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| Format: | Article |
| Language: | English |
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Elsevier
2023-11-01
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| Series: | Journal of Dairy Science |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S0022030223004411 |
| _version_ | 1797653968901373952 |
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| author | Che-Hsuan Huang Kenji Furukawa Nobuyuki Kusaba |
| author_facet | Che-Hsuan Huang Kenji Furukawa Nobuyuki Kusaba |
| author_sort | Che-Hsuan Huang |
| collection | DOAJ |
| description | ABSTRACT: This observational study aimed to use somatic cell score (SCS) and differential somatic cell count (DSCC), the combined proportion of polymorphonuclear leukocytes and lymphocytes in somatic cells, to investigate how mastitis affected milk production. Using generalized additive models, we analyzed 50,618 test-day records from 8,081 lactations from 7,912 cows in 197 herds between January 2021 and March 2022 to estimate the nonlinear interaction between SCS and DSCC, and the effects of lactation stages and seasons on milk yield, milk component percentages, and milk component yields by parity of cows. The results show that the interaction between SCS and DSCC on these traits was significant, nonlinear, and complex. When DSCC was high, the negative effects of SCS were minimal, even when SCS reached 8 (i.e., 3,200,000 somatic cells/mL). Cows with high DSCC could have milk yields similar to healthy cows, implying that these cows may have been in the early stages of mastitis and that the milk yield had yet to be affected. Contrastingly, when DSCC was low, milk loss due to high SCS was drastic, especially for cows in third or later lactations, whose milk yield could reduce from more than 35 kg/d to less than 15 kg/d (−59.9%). This tremendous milk loss in high-parity cows was likely due to their higher milk yield and higher risks of chronic mastitis. High SCS and low DSCC also led to a pronounced change in milk composition. The decrease in the percentage of lactose can be directly related to the damage of inflammation to the mammary gland, while the increase in fat and protein percentages was more attributable to the concentration effect resulting from the reduced milk yield. Compared with analyses based on categorized SCS and DSCC values, modeling these 2 indices directly helps us more precisely assess mastitis effects on milk yield and milk composition. For efficient milk production, our results indicate that we should prevent high-parity cows from entering a state of high SCS and low DSCC. |
| first_indexed | 2024-03-11T16:52:33Z |
| format | Article |
| id | doaj.art-98ec5f2dfb284b8b9d029b42a568a6c3 |
| institution | Directory Open Access Journal |
| issn | 0022-0302 |
| language | English |
| last_indexed | 2024-03-11T16:52:33Z |
| publishDate | 2023-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Dairy Science |
| spelling | doaj.art-98ec5f2dfb284b8b9d029b42a568a6c32023-10-21T04:21:41ZengElsevierJournal of Dairy Science0022-03022023-11-011061179427953Estimating the nonlinear interaction between somatic cell score and differential somatic cell count on milk production by parity using generalized additive modelsChe-Hsuan Huang0Kenji Furukawa1Nobuyuki Kusaba2Field Center of Animal Science and Agriculture, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555 JapanTokachi Federation of Agricultural Cooperatives, Obihiro, Hokkaido, 080-0013 JapanField Center of Animal Science and Agriculture, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555 Japan; Corresponding authorABSTRACT: This observational study aimed to use somatic cell score (SCS) and differential somatic cell count (DSCC), the combined proportion of polymorphonuclear leukocytes and lymphocytes in somatic cells, to investigate how mastitis affected milk production. Using generalized additive models, we analyzed 50,618 test-day records from 8,081 lactations from 7,912 cows in 197 herds between January 2021 and March 2022 to estimate the nonlinear interaction between SCS and DSCC, and the effects of lactation stages and seasons on milk yield, milk component percentages, and milk component yields by parity of cows. The results show that the interaction between SCS and DSCC on these traits was significant, nonlinear, and complex. When DSCC was high, the negative effects of SCS were minimal, even when SCS reached 8 (i.e., 3,200,000 somatic cells/mL). Cows with high DSCC could have milk yields similar to healthy cows, implying that these cows may have been in the early stages of mastitis and that the milk yield had yet to be affected. Contrastingly, when DSCC was low, milk loss due to high SCS was drastic, especially for cows in third or later lactations, whose milk yield could reduce from more than 35 kg/d to less than 15 kg/d (−59.9%). This tremendous milk loss in high-parity cows was likely due to their higher milk yield and higher risks of chronic mastitis. High SCS and low DSCC also led to a pronounced change in milk composition. The decrease in the percentage of lactose can be directly related to the damage of inflammation to the mammary gland, while the increase in fat and protein percentages was more attributable to the concentration effect resulting from the reduced milk yield. Compared with analyses based on categorized SCS and DSCC values, modeling these 2 indices directly helps us more precisely assess mastitis effects on milk yield and milk composition. For efficient milk production, our results indicate that we should prevent high-parity cows from entering a state of high SCS and low DSCC.http://www.sciencedirect.com/science/article/pii/S0022030223004411differential somatic cell countmastitismilk lossmilk composition |
| spellingShingle | Che-Hsuan Huang Kenji Furukawa Nobuyuki Kusaba Estimating the nonlinear interaction between somatic cell score and differential somatic cell count on milk production by parity using generalized additive models Journal of Dairy Science differential somatic cell count mastitis milk loss milk composition |
| title | Estimating the nonlinear interaction between somatic cell score and differential somatic cell count on milk production by parity using generalized additive models |
| title_full | Estimating the nonlinear interaction between somatic cell score and differential somatic cell count on milk production by parity using generalized additive models |
| title_fullStr | Estimating the nonlinear interaction between somatic cell score and differential somatic cell count on milk production by parity using generalized additive models |
| title_full_unstemmed | Estimating the nonlinear interaction between somatic cell score and differential somatic cell count on milk production by parity using generalized additive models |
| title_short | Estimating the nonlinear interaction between somatic cell score and differential somatic cell count on milk production by parity using generalized additive models |
| title_sort | estimating the nonlinear interaction between somatic cell score and differential somatic cell count on milk production by parity using generalized additive models |
| topic | differential somatic cell count mastitis milk loss milk composition |
| url | http://www.sciencedirect.com/science/article/pii/S0022030223004411 |
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