Nutrient digestibility of rice bran, with or without exogen enzymes, for weaned piglets

Abstract Text: The objective of the current study was to evaluate the digestibility of dry matter (DM), crude protein (CP), mineral matter, apparent digestible (DE) and metabolizable (ME) energy, and nitrogen retention of rice bran (RB), with or without exogen enzymes inclusion, in weaned piglets. Twenty-five crossbred barrows with initial weight 6.86 kg ± 1.3 kg, were alloted in a completely randomized design under five treatments and five replicates. The experimental unit was represented by one pig within its respective metabolic cage. The experimental period was 10 d, 5 d of adaptation and 5d of total feces and urine collection. The treatments were: Control diet (CD); CD + 30 % rice bran (CD + RB); CD + 30% RB + 200 mg/kg of carbohydrase (CD+RB+Carb); CD + 30% RB + 50 mg/kg of phytase (CD+RB+Phy); CD + 30% RB+ Carb + Phy (CD+RB+Carb+Phy). The control diet was based on corn (61.33%), skim milk powder (10%) and dried whey (15%). The enzymes used were: commercial phytase with an activity of 10,000 FTU/g; carbohydrase providing 10% of Galactomananase, 10% of Xilanase, 10% of ß-glucanase, 60% of malted barley and 10% of α-galactosidase. Isolated or combined with carbohydrase, phytase did not influence (p>0.05) the digestibility of rice bran nutrients. These results would be associated with adverse factors such as animal and nutritional profile of feedstuff. The DE – 3,062 kcal/kg and ME – 3,029 kcal/kg were similar to Brazilian tables for poultry and pigs (2011). The apparent digestibility coefficients of DM, CP, mineral matter and nitrogen retention were 65.47%; 72.58%; 36.59% and 62.21%, respectively. These results were similar some found in the literature using growing and finishing pigs, however, there are different results. The current study suggests that the used enzymes are not effective to improve nutritional value of gross energy, DM, CP and MM of rice bran for young pigs after weaning.

Table 1. Digestibility coefficients of rice bran for weaned piglets

Variables	Ingredients
	RB	RB+Carb	RB+Phy	RB+Carb+Phy	P-values	SEM
DM %	65.47	68.76	68.38	67.38	0,5730	0.866
CP %	72.58	76.13	75.45	75.26	0,8424	1.401
N retention %	62.21	63.69	64.12	65.40	0,9206	1.525
MM %	36.59	42.20	44.28	45.56	0,7090	2.774
DE (kcal/kg)	3,062	3,201	3,123	3,093	0,6105	40.677
ME (kcal/kg)	3,029	3,165	3,089	3,058	0,6255	40.915
ME:GE %	66.85	69.87	68.17	67.50	0,6271	0.813

Keywords: carbohydrase, metabolism, phytase