scholarly journals The impact of somatic cell count on milk yield and composition

2021 ◽  
Vol 24 (Monothematic issue) ◽  
pp. 49-52
Author(s):  
Kristína Tvarožková
2019 ◽  
Vol 15 (3) ◽  
pp. 9-21
Author(s):  
Piotr Guliński ◽  
Anna Kłopotowska

The aim of this paper is to develop a method for determining the typical chemical composition of the milk of Polish Holstein-Friesian (PHF) cows. The paper uses data collected from 1329 test-day milking records from 20 herds of PHF dairy cattle in Sokołów County, from 2009 to 2015. The effect of the following factors on the chemical composition of milk was determined: lactation stage (15 one-month stages); age of cows (lactations 1, 2, 3–4, and 5–7); genotype (share of PHF breed: less than 50%, 50–75%, 75–82.5% and more than 82.5%); somatic cell count (SCC) in 1 ml of milk (in thousands: 0–200, 200–400, 400–1000 and more than 1000); feeding level (fat to protein (F/P) ratio): ≤1.0, 1.0–1.4, 1.4–1.7 and >1.7); calving season (autumn/winter, spring/summer) and daily milk yield (milk yield in kg: ≤15, 15–25, 25–35 and >35). Nutrition and udder health status were found to be the main factors influencing the chemical composition of milk. For selected cows with optimally balanced feed rations (F/P ratio in milk from 1.1 to 1.4) and a low somatic cell count (SCC ≤200,000/ml), daily yield was the main factor affecting the chemical composition of the milk. It was also concluded that government and scientific publications on the PHF breed should take into account the impact of the F/P ratio, SCC and yield of milk on its composition.


2011 ◽  
Vol 78 (4) ◽  
pp. 489-499 ◽  
Author(s):  
Päivi J Rajala-Schultz ◽  
Audrey H Torres ◽  
Fred J DeGraves

Selective dry cow therapy (SDCT) has received increasing attention in recent years owing to global concerns over agricultural use of antimicrobial drugs and development of antimicrobial resistance. The objective of this study was to evaluate the effect of SDCT on milk yield and somatic cell count (SCC) in dairy herds in the USA. Cows in four Ohio dairy herds were categorized into two groups (low-SCC and high-SCC) at dry-off based on their SCC and clinical mastitis (CM) history during the lactation preceding the dry-off. Low-SCC cows were randomly assigned to receive or not to receive intramammary antibiotics at dry-off. Milk yield and SCC of these cows during the following lactation were compared using linear mixed effects models, adjusting for parity, calving season, stage of lactation, previous lactation milk yield and herd. Milk yield of untreated and treated low-SCC cows at dry-off did not differ significantly during the following lactation. Overall, treated low-SCC cows had 16% lower SCC (approximately 35 000 cells/ml, P=0·0267) than the untreated cows during the following lactation; however, the effect was variable in different herds. Moreover the impact of treatment, or the lack thereof, on milk yield varied considerably between herds. The results suggested that in some herds treating all cows at dry-off may be beneficial while in other herds leaving healthy cows without antibiotic dry cow treatment has no negative impact on milk yield or milk quality (SCC), and in fact, may be beneficial. Further studies are needed to identify characteristics of herds where treating all cows routinely at dry-off may be needed for maintaining good udder health and where switching to selective treatment of cows at dry-off would be the optimal approach to achieve best results.


Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1291
Author(s):  
Ryan S. Pralle ◽  
Joel D. Amdall ◽  
Robert H. Fourdraine ◽  
Garrett R. Oetzel ◽  
Heather M. White

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.


2009 ◽  
Vol 76 (2) ◽  
pp. 234-240 ◽  
Author(s):  
Bart Van der Straeten ◽  
Jeroen Buysse ◽  
Guido Van Huylenbroeck ◽  
Ludwig Lauwers

This paper uses a Markov chain model to analyse the dynamics in farm-size distribution among the Flemish dairy sector and the impact of quota policy regulation on such changes. The model predicts a decline of 24% in number of farms in 2014 compared with the current situation with a more liberal exchange policy and a decline of 18% with a restricted quota exchange policy. From these Markov chain model results, we analysed the impact of farm-size distribution on eight different milk quality parameters (total bacterial count, somatic cell count, coliform count, freezing point, urea-N, fat content and protein content and penalty-points). In general, larger farms produce higher quality milk than smaller farms, especially with respect to the microbiological parameters (total bacterial count, somatic cell count and coliform count). The change in farm-size distribution from a liberal quota exchange policy would decrease the average total bacterial count by 18·0%, the somatic cell count by 2·1% and the coliform count by 11·0%. The aggregate performance of the other parameters are smaller with improvements in all cases of <1%.


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