Silages from legume–cereal mixtures as a factor of dairy cow milk quality

Abstract

Currently, the prices of dairy cows feed with protein concentrates are rising and the climate change is also manifesting itself with a growing drought in animal production. These are the reasons why there is an increasing interest in growing silage from legume–cereal mixtures (L-C-M) and in increasing their share in feed rations for dairy cows. Furthermore, the L-C-Ms improve the soil fertility during the crop rotation. The effect of these feeds on milk quality was evaluated by adding L-C-M silages into feeding rations. Czech Fleckvieh and Holstein breed dairy cows (8 herds; feeding periods without and with L-C-M silages) were included in the evaluation for 3 years. There were used 126 L-C-M (experimental) and 463 control (without L-C-M) bulk tank milk samples in this dairy analysis. Lactose content, solids non fat content and total count of mesophilic bacteria in milk of L-C-M group was increased as compared to control (zero hypothesis probability varied from P ≤ 0.05 to P ≤ 0.001). On the contrary, as new knowledge, milk freezing point depression and somatic cell counts were decreased in L-C-M group as compared to control (P ≤ 0.001 and P ≤ 0.05). Other milk indicators such as contents of fat, crude protein, milk urea and thermostability (P > 0.05) were not affected by evaluated factor. The residues of inhibitory substances in bulk tank milk in the L-C-M group were not indicated, but one case was in the control group. Feeding of dairy cows with an increased proportion of L-C-M silage in the roughage component a part of the feeding ration is a safe way to replace part of the protein concentrates in animal feeding, regarding milk quality.

Keywords: breed, protein, milk freezing point depression, milk thermostability, hygienic milk indicators