Crambe cake protein as a replacement for soybean meal protein: Intake, digestibility, and ruminal parameters in lamb diets

The objective was to evaluate different levels of crambe cake protein (0, 250, 500, 750 and 1000 g/kg of DM) to replace soybean meal protein on the  intake, apparent digestibility coefficient (ADC), blood glucose, ruminal fermentation, and protozoal population in lambs. Two experiments were  performed. In experiment one, 40 crossbred male lambs weighing 20 ± 3.45 kg were used, distributed in a completely randomized design, to study intake  and ruminal parameters. In experiment two, 25 crossbred male lambs weighing 23.44 ± 1.04 kg were used to study digestibility. The intake of dry  matter and total carbohydrate (TC) (kg/lambs/day and g/kg0.75), crude protein (kg/lambs/day) and final body weight decreased with increase of crambe  cake protein as a replacement for soybean meal protein, while e t h e r e x t r a c t ( EE) intake (kg/lambs/day and g/kg0.75) increased. The ADC of EE  presented a positive linear effect and the ADC of TC and non-fibrous carbohydrates presented a negative linear effect. There was no interaction within  treatments and collection period (0, 3, 6 and 9 h) on ruminal fluid characteristics. Blood glucose presented a quadratic effect for levels of crambe cake  protein in diets (max. P = 35.18%), and linear increase for collection period. Ruminal pH showed a quadratic effect for sampling hours (max. P = 5.43 h).  For protozoa evaluation, the total amount, Entodinium, and Eudiplodium presented linear decreasing effects with treatment, while Isotricha,  Eudiplodium, Ostracodinium and the total amount of protozoa had a linear decrease with sampling hours. Soybean meal protein can be replaced by  crambe cake protein at up to 250 g/kg DM.