EVALUATION DE LA FEVEROLE ET DU POIS TRAITES OU NON-TRAITES A LA FORMALDEHYDE COMME SOURCE DE PROTEINES POUR LA VACHE LAITIERE
A first experiment was conducted to determine the nutritive value of fababeans (F) and field peas (P) as protein supplement in partial or total replacement of soybean meal (TS) in the concentrate part of the diet for dairy cows. In a second experiment, the nutritive value of formaldehyde-treated F and P was compared to untreated F and P. In each of the two experiments, a replicated 4 × 4 latin square design was used with 3-wk experimental periods. Dairy concentrates were fed ad libitum with corn silage in a 1:1 ratio (corn silage:concentrate) on a dry matter (DM) basis. In addition, the cows were fed 2.7 kg/day of grass hay. In experiment 1, a concentrate (SU) containing 10.8% TS and 0.2% urea was compared to three concentrates. The first one containing 25.0% F and 6.2% TS (FS), the second one 40% F (F) and the third one 35.0% P and 8.0% TS (PS). Dry matter intake and milk production were similar (P > 0.05) for all treatments at the level of 17.9, 17.8, 17.9 and 17.1 kg/day for DM and 22.7, 22.5, 22.7 and 21.7 kg/day of milk for treatments SU, FS, F and PS, respectively. Milk composition and digestibility of diets were not significantly (P > 0.05) affected by any treatment. In the second experiment, F and P without formaldehyde treatment were compared to F (FFo) and P (PFo) treated with 0.3 ml of a 40% formaldehyde solution per 100 g of crude protein. The formaldehyde treatment had no beneficial effect on milk production and feed digestibility. However, milk protein content was significantly (P < 0.05) increased with the formaldehyde treatment with values of 2.81, 2.95, 2.86 and 3.02% for treatments F, FFo P and PFo, respectively.