Evaluation of bioensilage of broccoli (Brassica oleracea L.) and oats (Avena sativa L.) as supplements for dairy cows
Abstract
An evaluation was performed on bioensilages incorporating different levels of broccoli (Brassica oleracea L.) and oats (Avena sativa L.) and addition of a microbial inoculant based on whey, as supplements for dairy cows in Ecuador. Production criteria and the ratio income/feed costs were determinants. The four treatments used were: T0 (100% fresh broccoli—presently used procedure), and the three bioensilages: T1, T2, and T3 (50-50, 62.5-37.5, and 75-25 % broccoli-oats, respectively), with ten replicates per treatment and a completely randomized experimental design. Observed variables were: pH and chemical composition of the ensilages, weight and body condition of the cows, milk production, incidence of detected estrus, and income/feed cost ratio. Statistical analysis utilized INFOStat/L 2009. A symmetric curve described the decrease in pH until reaching 4.3 during 22 d of fermentation. The ensilages analyzed from 15.9 to 18.5% dry matter, 26.3 to 29.4% crude fiber, and 16.7 to 19.3% crude protein (the former two fractions varying inversely and the latter directly with the level of broccoli). Treatment T3 gave the best mean results in daily milk production, 14.55 L; body condition score, 3.73 (on a 1 to 5 scale); cows observed in heat 89.2%; and income/feed cost ratio, 1.23. The microbial inoculant seems to accelerate and regulate the fermentation. These bioensilages have a higher concentration of nutrients than fresh broccoli and their use as supplements to dairy cows can increase milk production and profitability.