Effect of two systems of goat farming on milk production and quality

At present there are two methods of goat farming in the Czech Republic: Pasture and Indoor farming system. The grazing farming system is widespread especially for smaller herds. The goats are grazed during the day and kept in the stable during the night or in bad weather. Forage from pasture creates only a part of the feed ration, second part is the dry roughages which are added at the stable. The concentrated feeds are mostly served during milking at the milking parlour. The indoor farming system is used mainly in large herds. Goats are kept year-round in the stable with or without the possibility of using the outdoor runs. In this farming system is the goat‘s nutrition and completely based on a mixed diet that minimizes fluctuations in milk production.

The composition of goat milk depends on the main production factors constituting the farming system: genotype, reproduction and sanitary characteristics of animals, agro-climatic condition and socio-economical environment, farming methods such as feeding and milking. Relation between factors can be very close and complex (Morand-Fehr et al., 2007).

The breeding environment, technology and management have a direct effect on the cleanliness of the body surface of the farmed animals. Different housing systems create different conditions for a hygienic milk production (Regula et al., 2002). Stable objects provide animals with an appropriate thermal comfort, but mostly a lower level of hygiene in the breeding environment (Tombarkiewicz et al., 2009). Pasture farming systems minimize microbial contamination of teats and milk (Regula et al., 2002; McKinnon et al., 1990). Studies of Barkema et al. (1999) and Bartlett et al. (1992) have proved a relationship between the level of hygiene of breeding environment and body surface cleanliness and somatic cell count at dairy cows. The farms with the lowest incidence of mastitis had the cleanest cows.

The aim of the study was to determine the level of rearing environmental hygiene on the body surface cleanness and the production and quality of goat milk in two different farming systems of goats during the one lactation.

The monitoring was carried out six times during one lactation period on six goat farms (360 goats – breed: White short-haired). The average length of goat lactation was 280 days. The farms were divided into two groups according to systems of goat farming.

The first goat farming system was adopted in three farms (1294 goats). Goats were kept year- round in a barn with free access to outdoor runs. Goats were fed in the stable with a total mixed feed. Does, bucks and kids were housed separately. The second goat farming system was also used in three farms (362 goats). Goats were grazed during the day and were kept in a stable at night. In this method, the goats were supplemented their diet as well. Some extra selective feeding was added to overcome any dietary deficiencies.

All the farms had collecting yards for the goats before milking in milking parlour. Those were located in a closed building directly connected to the stable. Goats were milked twice a day. In the framework of cleaning of the udder was used only post-dipping with iodine disinfectant. The milking equipment was cleaned and disinfected with a regular alternation of acidic and alkaline cleansing and disinfecting agents after each milking.

Cleanliness of the body surface of a goat (tail head, upper rear limb, ventral abdomen, udder and lower rear limbs) was sensory evaluated by one reviewer before milking according to the five scales by Reneau et al. (2005).

After milking the milk samples (30 ml) were collected for the determination of selected microbiological parameters (total bacteria count - TBC, coliform bacteria count- CB, somatic cells count - SCC). Samples were chilled at 4 to 6 oC after collection and they were analyzed in the laboratory according the EN ISO standards. The obtained values were analysed by analysis of covariance (Statistica software package, StatSoft 7). The qualitative parameters were evaluated by non-parametric Kruskal-Wallis ANOVA.

Goats from the farming system II achieved higher (P<0.05) milk yield (+184 kg), fat (+6.1 kg) and protein (+6.4 kg) production than goats from the farming system I. (Table 1). Our results are consistent with the study of Morand-Fehr et al. (2007) that goats from indoor farming system have higher milk yield. In this system, the level of dry matter intake or ingested energy is the main factor influencing yield and composition of goat milk (Landau and Molle, 2005). A high level of intake, especially in early lactation, results in improved milk yield during this period (Morand-Fehr et al., 2007).

The clean udder and teats significantly contribute to the shortening the length of preparation udder for the milking and decision about the way of cleaning the teats prior to milking. The cleanness of the body surface of the goat depends directly on the system of goat farming (Table 2).

The count and types of microorganisms in a goat milk is influenced not only by climatic factors and their changes, but also by levels of hygiene, nutrition, stages of lactation, state of health, management of goat  farming, etc. (Kalantzopoulos et al., 2002; Delgado-Pertiñez  et al., 2003). The microflora of raw goat milk determines its sensory properties and results in varying quality of cheese during lactation (Raynal-Ljutovac et al., 2005).

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