Abstract #M48

# M48
Effect of Safeguard on fecal egg count and performance in received beef calves.
Antonio Jose Neto*1, Curt J. Bittner1, Galen E. Erickson1, Brandon L. Nuttelman2, 1Department of Animal Science; University of Nebraska, Lincoln, NE, 2Merck Animal Health, De Soto, KS.

Parasite infestations can reduce or limit feed intake and subsequently depress the performance due to decreased absorption of nutrients. Fenbendazole (Safeguard, Merck Animal Health) is indicated for use in cattle for removal and control of lungworms, stomach worms and intestinal worms. The objective of this study was to measure the effects of Safeguard on fecal egg count (FEC) and performance of newly received calves in the feedlot over the first 25 d. Treatments were applied to steers at arrival and were: Safeguard and Doramectin (Dectomax, Zoetis Animal Health) injectable (SG+DTX) or only Dectomax injectable (DTX). Three hundred sixty-eight (265 ± 20 kg) steers were used in a completely randomized design with 16 pens (8 replications per treatment and 23 steers per pen). The basal diet consisted 30% dry-rolled corn, 36% sweet bran), 30% alfalfa hay, and 4% supplement. Steers were assigned to pen based on processing order, with every other steer assigned to either SG+DTX or DTX. Once a pen replicate was filled, new pen replicates were started until all steers were assigned. On d 1, steers were weighed, and individual fecal sample collected. On d 19, fecal samples were collected per pen (10 samples/pen). Fecal samples were analyzed for FEC at a commercial laboratory. At the end of the receiving period, steers were limit-fed a diet consisting of 50% sweet bran and 50% alfalfa hay at 2% of BW for 5 d before being weighed. Data were analyzed using the Proc MIXED of SAS, with pen as the experimental unit. There were no differences in initial BW (P = 0.13), ending BW (P = 0.33), DMI (P = 0.41), ADG (P = 0.94), and G:F (P = 0.43) between SG+DTX or DTX. No difference for initial FEC (P = 0.45) was observed between treatments and averaged 16.9 eggs per 3 g of feces. However, FEC on d 19 was lower (P = 0.03) for animals receiving SG+DTX (FEC = 0.06 eggs per 3 g feces) compared with DTX (FEC = 0.50 eggs per 3 g feces). A combination of Safeguard and Dectomax reduced FEC of newly received calves in feedlot.

Key Words: dewormer, fecal egg count, performance