Evaluación del efecto de heno de Vigna (Vigna sinensis L.) y dos niveles de proteína no degradable en el rumen en la alimentación de novillas Holstein en desarrollo sobre el consumo, crecimiento y eficiencia de nutrientes

Abstract

The research was conducted from February to July 2018 and consisted of evaluation of growth, feed intake and nutrient digestibility in 32 developing Holstein heifers at 6.5 months after birth and 168 kg live weight. The study took place in the department of Sonsonate, El Salvador. Four treatments were used utilizing two different forage sources: Vigna (Vigna sinensis) or Pangola (Digitaria decumbens) at 25% dry matter (DM) and two levels of rumen undegradable protein (RUP): 26% and 36% crude protein (CP). respectively. The diets contained 35% King Grass (Pennisetum purpureum). The trial lasted 10 weeks. Dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), ash, nitrogen and creatinine were determined. Data were analyzed by a general linear model and a 2 x 2 factorial arrangement with SAS 9.4 (<0.05). The main results were that the inclusion of Vigna hay increased DM (6.94 to 7.37kg), organic matter (OM) (6.18 to 6.54kg), CP (896 to 951g) and NDF (1.72 to 1.84kg). At the level of total apparent digestibility, there were increases in DM (63.6 to 67.6 %), OM (66.5 to 70.2 %), NDF (55.9 to 59. 7 %) and FAD (49.5 to 55.1 %), At the level of excretion, there was an increase in urine and a decrease of fecal excretion. Regarding performance, efficiency and cost, there was a positive effect of the use of Vigna on daily weight gain and on feed cost per kilogram of weight gained. The main conclusions were that the inclusion of Vigna hay in the diet improved daily weight gain and decreased feed cost per kilogram of daily weight gain. In addition, substitution of Pangola Grass for Vigna in the diet increased nutrient intake and digestibility, as well as improved efficiency and performance in developing Holstein heifers