1664
Fecal Scores, Hemogasometry and Blood Parameters of Diarrheic Calves Fed Concentrate Containing Citrus Pulp as a Replacement For Corn
During the milk-feeding period, 24 calves were distributed into three treatments: 1) Control: starter feed containing corn as the main energy source (64% corn; 26% soybean meal; 6% wheat meal; 3% limestone; 1% minerals and vitamins, on dry matter basis); 2) 50CP: 50% (DM) of citrus pulp replacing corn, 3) 100CP: 100% (DM) of citrus pulp replacing corn. Animals were individually housed, with free access to water and concentrate, and received 4 L/d of milk replacer (20:16; 12.5% solids). After the diagnosis of diarrhea, evaluations of fecal score and measurement of respiratory and heart beat rate and rectal temperature were performed 3x/d, during three consecutive days. Blood samples were collected for blood cells count, electrolytes, blood gases and biochemical parameters analysis. Concentrate composition had no negative effect (P>0.05) on fecal score, which were higher than 2.5 during the first four weeks and decreased thereafter. Respiratory and heart beat rates were not affected (P>0.05), as well as rectal temperature, however values were always lower at 7h as compared to 12h and 19h evaluations, suggesting high impact of environmental conditions for sick calves. Inclusion of citrus pulp in concentrate had no effect (P>0.05) on hematocrit (23.9 %) and total erythrocytes (6.93 x 106/µL), but affected the mean corpuscular volume, with the highest value for animals fed 50CP (40.3fL). Increase of total leukocytes and neutrophils suggests the occurrence of an infectious instead of an alimentary diarrhea. Blood gases, electrolytes and biochemical data did differ (P>0.05) nor resulted in dehydration, acidosis, or any other metabolic disturbance in animals. There were no concentrate composition effects on blood pH (7.36), HCO3 (27.16 mmol/L), PCO2 (52.3 mmHg), K and Na (4.6 and 134.1 mEq/L, respectively), anion gap (12.2 mmol/L) and base excess (4.7 mmol/L). Plasma metabolites such as BHBA (0.057mml/L), glucose (85.6 mg/dL) and PUN (7.96 mg/dL) were not affected; however, total lactate and D-lactate were lower (P<0.05) for calves fed 50CP (16.0; 9.17 mg/dL respectively), as compared to control (20.8; 14.7 mg/dL) and 100CP (23.8; 14.4 mg/dL); while L-lactate lowest for 100CP (9.42; 6.8; 6.1 mg/dL for 100CP, 50CP and control, respectively). Replacement of corn by citrus pulp in the concentrate did not affect animals’ metabolism in response to the occurrence of diarrhea, being an alternative for feeding dairy calves.
Keywords: Byproducts; Metabolic disorders; milk-Feeding; Starter feed