Abstract: The objective of this study was to estimate the milk yield losses related to milk Somatic Cell Count (SCC) in Holstein cows of Turkey. Data included 17 study results conducted in Turkey between 1999 and 2009. Average SCC was determined as 705.419 cells mL^-1 and thus, daily Milk Yield (dMY), Lactational Milk Yield (LMY) and 305 daily milk yield losses were estimated as 14.56-17.44, 11.62 and 12.84-15.38%, respectively. Annual financial loss due to high SCC was estimated as $217.8 per milking cow. Therefore, reducing SCC in Holstein cows is seen an obligation for dairy sector of Turkey.

INTRODUCTION

In parallel to the world dairy sector, cattle husbandry plays a special importance for Turkey. Such that 91% of the total milk production is ensured from cows and also, culture and crossbred cows have 3 quarter portion in the total amount (Anonymous, 2009). Because of well adaptation characteristic of Holstein to temperate climatic conditions and its high production level, this breed is the mainly demanded one among culture cows in the country. However, Akbulut et al. (2007) clearly indicated that milk production levels of this breed are highly lower than those raised in the US or EU countries. In spite of many factors may be effective on this case, inadequate managemental applications can clearly be pointed out (Uzmay et al., 2001). Such as, improper bedding usage, unsuitable milking and feeding, or lacking observation on cow’s health status may result a failure in immunity system. In this situation, marked compositional changes in milk, or dramatic reduction in milk production may be detected as the 1st signs. Because of a high correlation between Somatic Cell Count (SCC) and bacteriological status of milk (Schutz et al., 1994), practically, an elevation of SCC or number of the white blood cells in raw milk is considered as abnormal and thus, measured SCC levels are accepted as a reflector for milk quality (Norman et al., 2000). Although, numerous studies (Erdem et al., 2007a; Duru and Tuncel, 2002 and Ulutas et al., 2004) have been published on milk yield characteristics or SCC levels of Holstein cows in Turkey, there is no detailed report on the relationship between milk production and SCC.

The goals of the present study were to evaluate studies conducted on milk yield and SCC of Holsteins raised in Turkey conditions, to determine mean SCC value of these cows and to estimate milk yield and financial losses related to SCC.

MATERIALS AND METHODS

The data were occurred from 17 previously investigations that had been conducted on SCC of milk in Holstein cows raised in Turkey. In the present study, only investigations included from 1999-2009 were considered. To calculate milk yield losses, Lactational Milk Yield (LMY), 305 daily Milk Yield (305 dMY) and daily Milk Yield (dMY) values of Holstein cows in Turkey reported by Akman and Kumlu (1999) and Akbulut et al. (2007) were used. In order to estimate, these losses related to SCC levels, a chart was utilized (Table 1).

Table 1:	Milk production losses related to SCC (Kaya et al., 2001)

Table 2:	Research results conducted on SCC of Holstein cows in Turkey

When different SCC vales were reported in an investigation (for instance, different seasonal values in the same study), average of these values was recorded and used as the SCC value. These were coded with (*) sign in Table 2.

RESULTS AND DISCUSSION

Table 2 shows that the range among references has a variable trend. In this study, overall mean of the data (705,419 cells mL^-1) was found as higher than the 400,000 cells mL^-1, which is the legal limit of raw milk in the EU countries (Norman et al., 2000). Besides, this mean was higher than the numbers obtained in some researches (Kul, 2006; Koc, 2007) conducted with other culture breeds in Turkey. This case could be explained by the close association between high milk production trait and SCC in dairy cattle. And also, Table 2 apparently indicates that some studies conducted by same researchers in the same region at different years (1 and 3; 9, 11, 13 and 15 and 12, 16 and 17) have alternating SCC values. In an earlier study, Uzmay et al. (2001) emphasized that managerial practices in dairy farms have significantly impression on subclinical mastitis risk. Thus, this alternation in the present study can be explained by the effect of the different managerial applications in the farms.

When the data were evaluated into four different SCC groups (Table 3), considerably low amount of references (17.65%) presented in normal (400,000 cells mL^-1) level. This finding is fairly dramatic, because, when compared with the SCC groups, the group with normal SCC threshold assumed in the EU countries was approximately 4 fold lower than the groups with elevated ones.

In an earlier study, Akman and Kumlu (1999) considered only Holstein cows enrolled to Cattle Breeders Assocation of Turkey (CBA) and LMY, 305 dMY and dMY of the cows were determined as 6248,5655 and 18.54 kg, respectively.

Table 3:	SCC (cells mL-1) frequencies of the results

Table 4:	Milk yield losses by two different references
*Only cows enrolled to CBA were assessed by the authors

Fig. 1:	Changes of milk yield losses in Holsteins of Turkey

Besides, Akbulut et al. (2007) reported that 305 dMY and dMY of Holsteins reared in Turkey were calculated as 4721 and 15.48 kg, respectively. According to these reports, predicted milk yield losses were given in Table 4 and when milk production level was considered to be 100 point, obtained yield levels related to milk losses in the present study were shown in Fig. 1.

When the mean SCC of this study (705,419 cells mL^-1) was assessed by Table 1, this value was presented between 566-1130 cells mL^-1 (x10³). Thus, according to this chart, milk loss per lactation was predicted as 726 kg cow^-1. Due to price of raw milk per kg in Turkey is 0.5 TL (equal to $ 0.3), annual milk loss per cow was estimated to be $ 217.8. Although, Kim and Heald (1999) emphasized that financial loss $ 200/year/cow is commonly acceptable, taking some precautions to decrease SCC in the herds is seen a useful step for dairy sector in Turkey.

CONCLUSION

Results here demonstrate that SCC of Holstein cows raised in Turkey conditions are relatively high. Moreover, milk production losses and also annual financial losses are closely associative with elevated SCC. In this sense, applying carefully managerial practices in the farms, such as carrying out proper milking procedure, recording regularly for SCC of raw milk, applying a payment system by lower SCC in milk and conducting more studies on the milk characteristics and its components in Holstein cows can be regarded as reasonable approaches.