Effects of gradual replacement of rapeseed cake with linseed cake in a grass silage-based diet for dairy cows

Authors

• Marketta Rinne Agricultural Research Centre of Finland, Institute of Animal Production, FIN-31600 Jokioinen, Finland
• Seija Jaakkola Agricultural Research Centre of Finland, Institute of Animal Production, FIN-3 1600 Jokioinen, Finland
• Matti Järvi Koivikko Agricultural College, FIN-91500 Muhos, Finland
• Pekka Huhtanen Agricultural Research Centre of Finland, Institute of Animal Production, FIN-3 1600 Jokioinen, Finland

DOI: https://doi.org/10.23986/afsci.72779

Abstract

Eight Finncattle cows were used in two replicated 4x4 Latin squares with 21 -day periods to study the effects of replacing rapeseed cake with linseed cake in proportions of 0, 1/3, 2/3 and 1 (on air dry basis), the total amount of supplement being 1.5 kg/day (on air dry basis). The basal diet consisted of silage fed ad libitum and a 4.5 kg/day (on air dry basis) barley:oats (1:1) mixture. The experimental diets had no effect on feed intake. Effective protein degrability (EPD) determined by the nylon bag method was higher for linseed cake than for rapeseed cake. Milk production decreased linearly (P<0.01), from 18.5 to 17.1 kg/day, when the proportion of linseed cake was increased. Milk fat content increased (P<0.05) by 3.4 g/kg but milk protein content tended to decrease (P<0.10) with an increase in linseed cake feeding. Despite clear differences in the fatty acid composition of linseed and rapeseed oils, experimental treatments had only minor effects on milk fatty acid composition. Several factors, including the slightly higher ether extract content, higher EPD and/or lower amino acid content of linseed cake than rapeseed cake, the different fatty acid composition of the two supplements and the presence of antinutritional compounds in linseed cake, may be responsible for the impaired milk production with linseed cake feeding.