Effect of different concentrations of dietary safflower seed on milk yield and some rumen and blood parameters at the end stage of lactation in dairy cows

Abstract

In this study, the effects of different concentrations of dietary safflower seeds (SS) were examined for milk production, milk fat and some rumen and blood parameters at the end stage of lactation in dairy cows. Four Holstein cows were assigned to a 4 × 4 Latin Square design with four stages. All stages had 14 d of adaptation and 7 d of data collection periods. The diets were formulated as isoenergetic and isonitrogenous. Cows were fed four concentrate mixtures containing 0% (Control; C), 12.5% (S-I), 25% (S-II), or 37.5% (S-III) crushed SS during the experimental period. Safflower seed intake was distributed as 0 (C), 1 (S-I), 2 (S-II) and 3 (S-III) kg/d/cow. Cows were fed 8 kg concentrate, 2 kg wheat straw, and corn silage ad libitum (approximately 20 kg). Diet S-III caused a decrease in efficiency of milk production and diet S-II provided a much further efficiency in milk production (C = 13.39±0.23, S-I = 12.94±0.26, S-II = 13.46±0.24 and S-III = 11.83±0.52 kg). Diets had no significant effect on milk fat (C = 3.99±0.18, S-I = 4.09 ± 0.16, S-II = 3.87±0.35 and S-III = 3.75±0.30%). There was no difference in rumen fluid and blood parameters. Short-time feeding of up to 2 kg/d safflower seed had no negative effects on milk yield, milk fat, and some serum parameters, but 3 kg/d safflower seed reduced milk production. Safflower seed can be safely fed at up to two kilograms daily at the end stage of lactation in dairy cows.