Performance and cheese quality of Brown cows grazing on mountain pasture fed two different levels of supplementation

Abstract

The aim of this study was to evaluate the effect of concentrate supplementation of Brown cows grazing a mountain pasture on animal performance, and on the quality and sensory characteristics of milk and cheese. The trial was carried out on a high mountain pasture (Malga Juribello, Italy, 1900 m) where 2 homogeneous groups of 12 Brown Cows fed 2 different levels of supplement: low (LS), 1.6, and high (HS), 4.8 kg of organic matter/day (OM/day) for 5 weeks. Animal performance and milk yield were assessed, and chemical, physical and sensorial analyses of milk and cheese were also performed. The average herbage intake was 13.3 kg OM/day, with a significant effect related to supplement level (low, 14.4 vs. high, 12.1 kg OM/day). Body condition score (BCS) variation was always negative, but it was lower in the HS group (− 0.15 vs. − 0.37) which also had a higher milk yield (15.5 vs. 14.6 kg/day) and better cheese making properties. Analyses showed that the level of supplement had an effect on the chemical and fatty acid composition of the cheese. Cheese texture analysis showed an effect on springiness and chewiness, which was higher in HS; while adhesiveness was higher in LS. Sensory profiling performed using conventional quantitative descriptive analysis allowed the identification of sensory attributes correlated with the level of supplement and only partially compatible with texture analysis. However perceivable differences in analytical description were probably not high enough for the average consumer to identify the integration effect: indeed discrimination tests based on overall profile carried out by trained judges did not show significant differences in the milk and cheese produced by experimental groups. In conclusion, the HS level offered to grazing cows allowed improvement of milk and cheese yield, milk renneting properties, quantity of unsaturated fatty acids (a part C18:3) in cheese and BCS with a limited effect on sensory qualities; however a reduction of herbage intake was observed.