Crushed crambe from biodiesel production as replacement for soybean meal in the supplement of steers grazing

Abstract

To evaluate the substitution of soybean meal by crushed crambe as a source of protein, five crossbred steers rumen cannulated weighting 426 ± 25 kg BW were distributed in a 5 × 5 Latin square design. The steers were allocated in different levels of crushed crambe groups (0, 25, 50, 100 and 150 g/kg in concentrate supplement). Dry matter intake (DMI), rumen fluid pH, nitrogen (N) urinary excretion, propionate and isovalerate ruminal concentrations increased linearly (p < .05) with the replacement of soybean meal by crushed crambe. Crude protein (CP) intake, butyrate and valerate concentrations, and N retention and balance (g/d) showed linear decreases by the inclusion of crushed crambe. There was a quadratic decrease (p < .05) for neutral detergent fibre (NDF) intake and valerate concentration. Total short-chain fatty acids (SCFAs) increased quadratically (p < .05) with the inclusion of crushed crambe. The supplement and total DMI, digestibility of DM, CP and NDF, N–NH₃, acetate, isobutyrate concentrations and intake, excretion faecal and total of N, microbial protein synthesis, urinary excretion and blood concentration of urea and creatinine were not affected (p > .05) by the crushed crambe inclusion in the diet. It is recommended that 100 g/kg of the crushed crambe inclusion replacing soybean meal supplements to grazing steers because improved supplement DMI and total SCFAs, reducing ruminal fermentation and nitrogen excretion, without affecting digestibility and microbial protein synthesis.

Highlights

• DM intake and digestibility were not affected in steers fed crushed crambe.

• Urinary N excretion increased with crushed crambe replacing soybean meal.

Keywords:

• Biodiesel
• by-product
• Crambe abyssinica
• oilseed
• ruminal fermentation

Disclosure statement

No potential conflict of interest was reported by the authors.