Effect of grazing on composition, fatty acid profile and nutritional indices of the goat milk and cheese

Abstract

The global goat milk production was approximately 19.9 mln t in 2019 and relatively continuously has been increasing during the last decades (FAO, 2021). Goat milk production has been growing, but the quantity of different types of goat milk products (typically cheese and yoghurt) has been also increasing year by year. In recent years, goat cheeses have gained increased popularity among consumers due to their nutritional value and health advantages. Small-scale farmers generally produce goat cheeses. This way, cheeses and other goat milk-based products have played an important role in the economic viability of farmers in the world. It is also necessary to add that goat cheeses are traditionally one of the crucial goat milk products produced, traded and consumed in large amounts in the world. Goat breeding and milk production are generally based on natural pastures in rural areas. After forests, grasslands and natural pastures are the most important ecosystems in the world because approximately 37% of the Earth’s terrestrial land surface (more than 50 mln km2, excluding Greenland and Antarctica) is covered by grasslands and natural pastures (O’Mara, 2012). Natural pastures are an essential resource for grazing-based animal production worldwide. In addition, sustainable small ruminant species (such as goat) breeding and keeping play an important role in the economy of marginal ABSTRACT. Twenty lactating Hungarian native goats were randomly divided into two groups to evaluate the effect of extensive grazing on the somatic cell counts (SCC), composition and fatty acid profile of milk and semi-hard cheese. The following important nutritional indices of goat milk and cheese fat were calculated: atherogenic index (AI), health-promoting index (HPI), hypercholesterolemic saturated fatty acids (HFA), hypocholesterolemic/hypercholesterolemic ratio (H/H), linoleic acid/α-linolenic acid ratio (LA/ALA) and thrombogenicity index (TI). The experimental period lasted for 38 days, encompassing the first four weeks as the period of adaptation to the natural pasture and the last ten days as the experimental period. The extensive grazing resulted in significantly higher concentrations of rumenic acid and lower n-6/n-3 ratio in milk (0.49 vs 0.67%, P < 0.01; 3.97 vs 1.49, P < 0.001) and in cheese (0.44 vs 0.63%, P < 0.001; 3.96 vs 1.54, P < 0.001). The extensive grazing significantly decreased the AI, HFA and LA/ALA, but on the other hand, increased the HPI and H/H indices in goat milk and cheese, respectively. The study results suggest that consumers have greater nutraceutical benefits from consuming milk and cheese from goats kept on natural pasture. Received: 20 August 2021 Revised: 11 November 2021 Accepted: 13 December 2021