TY  - JOUR
T1  - Intake, Nutrient Digestibility and Milk Yield of Dairy Cows Fed Urea and Two Levels of Crude Protein in Diets with Sugar Cane
AU - de Jesus, Elmeson Ferreira AU - Conti, Luis Henrique Andreucci AU - Tomazi, Tiago AU - Diniz, Marina Elena AU - Migliano, Amaral AU - Prada e Silva, Luis Felipe AU - Renno, Francisco Palma AU - Veiga dos Santos, Marcos 
JO  - Journal of Animal and Veterinary Advances
VL  - 11
IS  - 22
SP  - 4135
EP  - 4142
PY  - 2012
DA  - 2001/08/19
SN  - 1680-5593
DO  - javaa.2012.4135.4142
UR  - https://makhillpublications.co/view-article.php?doi=javaa.2012.4135.4142
KW  - Degradability
KW  -nitrogen source
KW  -milk yield and composition
KW  -diary cows
KW  -Brazil
AB  - The objective of this study was to evaluate the effect of 
  two Crude Protein (CP) levels and two nitrogen sources in the diets of dairy 
  cows on DM and nutrient intake, total apparent digestibility, ruminal fermentation, 
  milk yield and composition and energy balance using sugarcane as forage. Twelve 
  multiparous Holstein cows, averaging 235 days of milking and 22.0 kg of milk 
  day were distributed into three balanced and contemporary 4x4 Latin squares. 
  The study consisted of four experimental periods of 21 days with 14 days for 
  diet adaptation and the remainder for sampling. The cows were fed isocaloric 
  diets with <I>ad libitum </I>intake and forage based on sugarcane in a 2x2 factorial 
  arrangement of treatments: two main nitrogen sources (soybean meal andurea) 
  and two levels of CP and 156 g CP kg<SUP>-1</SUP> DM). Milk samples for compositional 
  analysis were collected on the 14-17th days of each period. Ruminal fluid samples 
  were collected by an esophageal tube, 3 h after morning feeding, for pH, short 
  chain fatty acid and ammonia nitrogen analysis. Apparent digestibility was determined 
  by means of an internal indicator (ADFi). No effect of diet was observed on 
  Dry Matter Intake (DMI) (kg/day), net energy for lactation (Mcal/day) or total 
  nutrientapparent digestibility. Interactions between nitrogen source and diet 
  crude protein content were observed on rumen pH (p = 0.007) and acetate to propionate 
  ratio (p = 0.003). A tendency was observed (p = 0.052) toward an effect of CP 
  levels on milk protein yield (kg/day) as the cows fed diets with soybean meal 
  produced more milk protein than those fed diets with urea. The results indicate 
  that diets with lower levels of CP do not alter the milk yield and composition 
  of dairy cows in the final third of lactation.
ER  -