The comparison of hand and machine milking on small family dairy farms in central Croatia

D Filipovic and M Kokaj*

Faculty of Agriculture, University of Zagreb, Croatia
*Agricultural engineer, graduated on Faculty of Agriculture, University of Zagreb, Croatia
dfilipovic@agr.hr

Abstract

The objective of this short experiment was to determine the effect of two different milking methods (hand vs. machine milking) on milk yield, milking time, milk composition, somatic-cell-count and microorganisms in milk. Milk samples were collected during one-month period from ten small family farms located in central Croatia.

The average milk yield per milking was significantly higher (5.06 vs. 3.69 L, P<0.05) and milking time was significantly shorter (4.42 vs. 6.05 min, P<0.05) at machine than hand milking. Differences in milk composition (fat, protein and lactose contents) at different milking methods were not significant. Average value of SCC was much higher (65%) in milk from hand milked than machine milked cows, but difference was not significant due to the great variance of the values. Average value of microorganisms was significantly higher (P<0.05) in milk from hand milked cows.

The results showed that introducing of machine milking instead of hand milking can improved the hygienic quality of milk and increased the work efficiency on small family farms in Croatia.

Key words: Microorganisms, milk composition, milk yield, milking time, somatic-cell-count

Introduction

In Croatia there are about 61.000 milk producers, and from this number the greatest part are small family farms with 1-3 cows (61%) or 4-9 cows (34%), so 10 and more cows have only 5% producers (Grgic 2002). Milking machine have only 23.5% of Croatian milk producers (Filipovic et al 2005), since farmers with small herds usually chose hand milking method because of minimal capital investment, equipment maintenance and cleaning (Akam et al 1989). Till 1^st January 2003 farmers in Croatia were paid for their milk only according to the fat percentage in milk, but from this date according to the new regulations the main criteria for paying is hygienic quality of milk. The indicators of hygienic quality of milk delivered by farmers are SCC (somatic-cell-count) and total number of microorganisms. The SCC in raw milk is also one of the main criteria of its quality evaluation in all EU and North American countries. The worldwide researches conducted by leading scientific institutes show that mastitis and SCC are the most common and vital problems in milk production (Przysucha and Grodzki 2004). The first analysis in Central laboratory for milk control showed that almost 80% of raw milk delivered by Croatian farmers had no proper hygienic quality according to the new regulations in case of SCC and total number of microorganisms (Kostelic 2003). The aim of this work was to estimate the effect of hand and machine milking on milk production, milk composition and hygienic quality of milk on small family dairy farms in central Croatia.

Materials and methods 

The experiment was carried out on ten small family dairy farms in the Zagreb County in central Croatia. On five farms cows were milked by hand and on the other five by machine. The number of cows on each farm was between 4 and 9, and all cows were Simmental breed. Milking time and milk yield were recorded in the morning and the afternoon milking sessions, and milk samples were collected in sterilized bottles to be analysed. Fat, protein and lactose content in milk were determined using a Milkoscan FT 120, somatic cell counts using a Fossomatic 90 and total number of microorganisms using a Bactoscan FC instrument.

The obtained data were analysed using the SAS statistical software (SAS 1990) and applying the analysis of variance (ANOVA). The T-test was used to identifying differences between the mean results and the differences had been considered as significant if P<0.05. The logarithms of SCC and microorganisms number were used for trying to normalize data distribution.

Results and discussion 

The milk yield during this experiment ranged from 2.0 to 7.5 L per one milking and average milk yield per milking was significantly higher (P<0.05) at machine than hand milking (Table 1). The milking time ranged from 3.0 to 8.0 min and was significantly shorter (P<0.05) at machine than hand milking. Because of significantly higher milking extraction rate, the work efficiency on farms with machine milking is much higher.

During this experiment the values of fat and protein content ranged from 3.59 to 6.55% and from 2.71 to 4.38%, respectively at both milking methods. The values of fat and protein content were higher in milk from hand milked cows but differences were not significant. The values of lactose content ranged from 4.34 to 4.88% at both milking methods, and lactose content was higher in milk from machine milking cows without significantly difference (Table 2).

Similarly results also reported Dang and Anand (2007) compared hand milking and different machine milking methods. On the contrary, Hemsworth (2003) reported that machine milking could be associated with stress and a significant reduction in milk yield and quality. However, the cow milking machines became generally accepted because of more efficient milking and the reduction of hand labour.

According to the present regulations in Croatia, allowed values for first class milk are 250.000 somatic cells and 100.000 microorganisms in 1 ml of raw milk. During the experimental period, less than 250.000 somatic cells per ml contained 81% samples from machine milked cows and 57% samples from hand milked cows. The values of SCC in 1 ml of raw milk ranged from 0.48 x 10⁵ to 4.98 x 10⁵. Average value of SCC was much higher (65%) in milk from hand milked than machine milked cows, but difference was not significant due to the great variance of the values. The statistical analysis of SCC number was also done after transformation to log ₁₀, but without changing of significance. In the same time, less than 100.000 microorganisms per ml contained 92% samples from machine milked cows and 45% samples from hand milked cows. The values of microorganisms in 1 ml of raw milk ranged from 0.23 x 10⁵ to 5.34 x 10⁵, and average value of microorganisms was significantly higher (P<0.05) in milk from hand milked cows. The statistical analysis of microorganisms number was also done after transformation to log ₁₀. Dang and Anand (2007) also found that SCC was higher at hand milking method. Harmon (1994) reported that there is a linear inverse relation between SCC and milk production, because higher SCC values characterised some infection and resulted in a reduction of milk yield. Deluyker et al (1993) also found that the higher SCC indicated clinical mastitis associated with significant milk yield loss. The mass occurred mastitis are the source of considerable losses directly borne by farmers such as lower milk production, lower milk price and growing costs of veterinary service (Przysucha and Grodzki 2004). Because of new payment system in Croatia the udder health and the hygienic quality of milk became more and more important. The results of this study showed that introducing of machine milking instead of hand milking could help Croatian dairy farmers to improving their milk production with higher work efficiency and hygienic quality of milk. The introducing of machine milking will also improve the milker's health reducing the hard work with hand milking.

Conclusion 

• The average milk yield per milking was higher and milking time was shorter at machine than hand milking, while differences in milk composition (fat, protein and lactose contents) at different milking methods were not significant.

  
  

• Much better hygienic quality, determined by SCC and microorganisms in 1 ml, characterised milk from machine milked cows.

  
  

• The results showed that introducing of machine milking instead of hand milking can improved the hygienic quality of milk and increased the work efficiency on small family farms in Croatia, but farmers must be educated to adopt machine milking method.

References 

Akam D N, Dodd F H and Quick A J 1989 Milking, milk production hygiene and udder health. Food and Agriculture Organization, Rome.

Dang A K and Anand S K 2007 Effect of milking systems on the milk somatic cell counts and composition. Livestock Research for Rural Development 19: 1-9 http://lrrd.org/lrrd19/6/dang19074.htm

Deluyker H A, Gay J M and Weaver L D 1993 Interrelationships of somatic cell count, mastitis, and milk yield in a low somatic cell count herd. Journal of Dairy Science 76: 3445-3452  http://jds.fass.org/cgi/reprint/76/11/3445

Filipovic D, Grgic Z, Par V and Tratnik M 2005 Opremljenost hrvatskih poljoprivrednih kucanstava strojevima i opremom. Drustvena istrazivanja.14: 565-577

Grgic Z 2002 O programu razvitka govedarske proizvodnje do 2010. Mljekarski list 39: 22-25

Harmon R J 1994 Physiology of mastitis and factors affecting somatic cell counts. Journal of Dairy Science 77: 2103-2112  http://jds.fass.org/cgi/reprint/77/7/2103

Hemsworth P H 2003 Human-animal interactions in livestock production. Applied Animal Behaviour Science 81: 185-198.

Kostelic A 2003 Losa higijena i tehnika muznje smanjuju zaradu. Mljekarski list 40: 14-15

Przysucha T and Grodzki H 2004 The relationships between collection system, delivery size and season and somatic cells level count in raw milk classified to the highest quality classes. Electronic Journal of Polish Agricultural Universities. 7: 1-9 http://www.ejpau.media.pl/volume7/issue1/animal/abs-01.html

SAS 1990 SAS User's guide. Version 6., SAS Institute, Cary, NC, USA.

Received 8 September 2008; Accepted 17 April 2009; Published 1 May 2009

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