Effect of diets containing whole or ground corn with and without soybean hulls on feeding calves during the suckling phase

Abstract

24This work evaluated the use of soybean hulls and whole or ground corn in the diets of 25 suckling calves. Diets containing two levels of soybean hull inclusion (0 and 400.1 g/kg) and 26 corn in different physical forms (whole or ground) were evaluated in the diets of newborn 27 crossbred dairy calves that were housed and received experimental diets plus four liters of 28 milk per day over 56 days. Weekly samples of food, diets and leftovers were taken to 29 determine dry matter and nutrient intake. To evaluate the apparent digestibility, samples were 30 taken from the diets, leftovers and feces for three consecutive days using titanium dioxide as 31 an indicator. Blood samples were also collected to evaluate the blood indicators. Including 32 soybean hulls in the diet increased the consumption of neutral detergent fiber but reduced the 33 consumption of non-fibrous carbohydrates, which was also reduced by using whole corn in 34 the diet. Total digestible nutrient consumption did not vary, although its value was reduced by 35 using whole corn and including soybean hulls. The apparent digestibilities of the dry matter 36 and crude protein were similar, resulting in similar performances between the animals, 37 regardless of the factors analyzed. Using soybean hulls or whole corn did not affect blood 38 indicators or feeding costs. Soybean hull or whole corn usage did not affect the performance 39 of crossbred dairy calves during rearing. 41 Although milk producers are efficient at producing heifers, male cattle production is 42 typically neglected. In Brazil, the number of cows milked corresponds to 23 million animals 43 [1] with a birth rate of 50% male; thus, 11.5 million calves are produced annually. Although 44 no official data exist on the number of calves slaughtered shortly after birth in Brazil, 45 approximately 40% of these calves are slaughtered in their first days of life, representing 46 approximately 4.6 million calves. This occurs because producers consider that these calves 47 will increase their production costs without favorable financial returns; however, these 48 animals can yield good productive results when their nutritional and hygiene requirements are 49 fulfilled [2], mainly during the first days of the animal's life (0 to 60 days). 50This period is the most costly in the production system; thus, solutions are needed to 51 balance these costs, such as using palatable solid foods, which stimulate the animals to eat. 52This allows the animals' weaning age to be reduced because they benefit from more efficient 53 use of the nutrients in solid food [3,4], which reduces the problems caused by weaning the 54 animals early [5][6][7], increases the amount of milk available for sale and reduces the demand 55 for labor. 56However, the use of feedstuff, such as corn and soybeans meal, which are traditionally 57 used in animal feed, in the biofuel production, has increased the price of these inputs [8]. 58Thus, alternatives to these foods are needed to reduce feed costs, such as by-produ...