1663
Fecal Scores, Hemogasometry and Blood Metabolites of Diarrheic Calves Fed Concentrate Containing Sugar Cane Molasses or Glucose Syrup as a Replacement For Corn
During the milk-feeding period, 32 calves were distributed into four treatments: 1) Control: starter feed containing corn as the main energy source (65% corn; 24% soybean meal; 10% soybean hulls, 1% minerals and vitamins, on dry matter basis); 2) 5SCM: 5% (DM) of sugar cane molasses replacing corn; 3) 10SCM: 10% (DM) of sugar cane molasses replacing corn; 4) 5GS: 5% glucose syrup (DM) 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 rates as well as 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 for all treatments. There was a tendency (P<0.09) for higher rectal temperature (39.1; 39.4; 39.5; 39.1 for Control, 5SCM, 10SCM and 5GS, respectively) and respiratory rate (36.2; 41.9; 46.3; 34.0 breaths/min for Control, 5SCM, 10SCM and 5GS, respectively) for calves fed both levels of molasses. Respiratory rate, heart beat rate and rectal temperature increased during the day, as temperature-humidity index also increased. Replacement of corn by co-products had no effect (P>0.05) on total erythrocytes (6.87 x 106/µL), mean corpuscular volume (37.9 fL) and hemoglobin (8.99 g/DL), however hematocrit was increased (P<0.05) as co-products were fed (23.0a; 26.4b; 28.9c; 25.1b for Control, 5SCM, 10SCM and 5GS, respectively). There were no concentrate composition effects on blood pH (7.33), HCO3 (28.18 mmol/L), PCO2 (52.6 mmHg), K and Na (4.9 and 135.7 mEq/L, respectively), anion gap (13.38 mmol/L) and base excess (2.33 mmol/L) concentration. Plasma metabolites were also not affected by replacement of corn by co-products in the concentrate, with values of BHBA (0.06 mml/L), glucose (82.5 mg/dL), total protein (6.8 g/dL), PUN (7.1 mg/dL) and total lactate (16.45 mg/dL) within the normal physiological range for dairy calves during the milk-feeding period. Replacement of corn with molasses or glucose syrup in the supplement did not affect animals’ metabolism in response to the occurrence of diarrhea and can be used as an alternative for feeding dairy calves.
Keywords: Byproducts; Metabolic disorders; milk-feeding; Starter feed