Veterinary Parasitology 183 (2012) 284–291 Contents lists available at ScienceDirect Veterinary Parasitology jou rnal homepage: www.elsevier.com/locate/vetpar Cooperia punctata: Effect on cattle productivity? a,∗ b c c Bert E. Stromberg , Louis C. Gasbarre , Audie Waite , David T. Bechtol , d a a e Michael S. Brown , Nicholas A. Robinson , Erik J. Olson , Harold Newcomb a College of Veterinary Medicine, University of Minnesota, 1971 Commonwealth Avenue, St. Paul, MN 55108, United States b Gasbarre Consulting, Crazy Woman Drive, Buffalo, WY 82834, United States c Agri Research Center, Inc., 16851 Hope Road, Canyon, TX 79015, United States d Ruminant Nutrition and Management, West Texas A&M University, Canyon, TX 79016, United States e Merck Animal Health, 35500W. 91st St., DeSoto, KS 66018, United States a r t i c l e i n f o a b s t r a c t Article history: Cooperia spp. have become the most prevalent parasites in United States cow/calf opera- Received 23 March 2011 tions as observed in the USDA NAHMS (National Animal Health Monitoring System) Beef Received in revised form 6 July 2011 Cow/Calf survey in 2008. This is at least in part due to the widespread use of macrocyclic Accepted 13 July 2011 lactones that have recently been shown to have a reduced activity against these parasites. The effects of Cooperia spp. on cattle productivity are largely unknown. This study was Keywords: conducted to assess their effect upon cattle housed under conditions found in American Beef cattle production feedlots. Two hundred yearling calves (average weight 460 lb/209 kg) were acquired from Cooperia punctata northwestern Arkansas and northeastern Oklahoma and were vaccinated and dewormed Anthelmintic resistance Daily weight gain upon arrival at the feedlot. Animals were comingled and preconditioned for approximately Feed consumption one month, and were fed a standard growing ration throughout the study. Calves were Histology randomly divided into two groups (n = 80, infected and control) and each group was fur- ther divided into two replicate pens (n = 40). Calves from the two infected pens were orally 5 5 × inoculated with a gavage of 1 10 and 0.825 × 10 infective larvae of a recent isolate of Cooperia punctata on day 0 and 14, respectively, with the two control pens receiving a simi- lar volume of tap water. Data collected included biweekly fecal egg counts, daily individual feed consumption and weight gain over the 60-day test period. The presence of C. punctata (>99% of recovered worms) was confirmed by necropsy and recovery from the small intes- tine on days 35 and 60 post infection (PI) in a subset of animals. Egg counts were positive by day 14 PI and remained at numbers similar to values seen in field studies. The control group gained weight 7.5% more rapidly (p = 0.02) than infected animals (3.24 lb/1.47 kg per day vs. 3.0 lb/1.36 kg per day, respectively). The Cooperia-infected calves also consumed 1.5 lb (0.68 kg) less dry feed per day than the control animals (p = 0.02). These data suggest that C. punctata has a deleterious effect on both appetite and nutrient uptake or utilization. At necropsy (days 35 and 60), the draining mesenteric lymph nodes of infected animals were increased in size and the small intestinal mucosa was thickened and covered with a thick layer of mucus in the infected animals. The most prominent histological changes in the Cooperia- infected animals included a moderate increase in the number of intraepithelial lymphocytes and globule leukocytes, as well as aggregates of eosinophils within the lower lamina propria. The only significant difference was an increase in the goblet cell density at day 60. Anthelmintic sensitivity/resistance of the Cooperia isolate used was determined by treatment of one pen of infected calves with a macrocyclic lactone and the other pen with a benzimidazole at the completion of the study. The macrocyclic lactone treatment (n = 40) ∗ Corresponding author. Tel.: +1 612 625 7008; fax: +1 612 625 5203. E-mail address: [email protected] (B.E. Stromberg). 0304-4017/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.vetpar.2011.07.030 B.E. Stromberg et al. / Veterinary Parasitology 183 (2012) 284–291 285 did not remove the parasites (FECRT = 8.8%), while treatment with a benzimidazole was very effective (FECRT = 98.1%). This study demonstrated that C. punctata has a significant effect on cattle productivity, both reduced weight gain and decreased feed intake compared to controls. © 2011 Elsevier B.V. All rights reserved. 1. Introduction a recently isolated field strain of a macrocyclic lactone- resistant C. punctata and daily feed intake and weight gains Cooperia spp. have become the most prevalent nema- of cattle in a feedlot setting were monitored. The study tode parasite in the United States cow/calf operations as also evaluated the sensitivity of this strain of C. punctata observed in the USDA NAHMS Beef Cow/Calf survey in to a macrocyclic lactone and a benzimidazole. The small 2008 (Stromberg et al., unpublished data). This is at least intestines were also examined histologically to determine in part due to the widespread use of macrocyclic lactones if there were any morphological changes that might be that have a reduced efficacy against parasites of this genus. related to weight gain and nutrient uptake through the Macrocyclic lactones have changed the way that cattle are mucosa of infected and control animals. managed, due to their high efficacy, broad spectrum of action, and large margin of safety. Their availability led 2. Materials and methods to the development of strategic parasite control programs to reduce the parasite population on pasture and thus 2.1. Animals improve overall animal productivity and increase return on investment. Parasite free status has resulted in a significant improvement in production parameters. A large (4 site) Approximately 200 steer and bull calves of unknown study by Ballweber et al. (1997) showed significant weight backgrounds were acquired from sale barns in northwest- gains (0.152–0.272 kg/day) of parasite free stocker cattle ern Arkansas and northeastern Oklahoma at an average when compared to controls. A study in Minnesota found weight of 459.8 lb (208.6 kg). Upon arrival at the feed- that parasite free calves out gained controls by 19.3 kg and lot, at the Agri Research Center, Inc., Canyon, TX, calves 13.2 kg in two successive years. After adjusting for birth- were treated at the label dosage of fenbendazole (10 mg/kg) ® date and birthweight, parasite free calves demonstrated and levamisole (8 mg/kg), implanted (Ralgro ), vaccinated ® ® an Average Daily Gain (ADG) of 0.13 kg more than controls (Vista 5 , Calvary 9 ), received metaphylactic therapy ® over the two year period (Stromberg et al., 1997). (Excede ), and intact bulls were surgically castrated. Calves This widespread usage of macrocyclic lactones has were then comingled and preconditioned for approxi- resulted in changes in husbandry practices, such as mately 1 month. increased stocking rates, and a reduction in the uti- Animals were preconditioned in order to minimize lization of pasture management practices to control the health issues during the study period as well as to estab- effects of parasitism. These changes have contributed to lish a consistent consumption pattern prior to infection. the selection of drug resistant helminth parasites. Resis- This period of time was also used to determine the para- tance to benzimidazoles and macrocyclic lactones has been site status of animals. Animals were fed a standard feedlot well documented in small ruminants (Waller, 1997). A growing ration comprised of the following ingredients: recent study in cattle (Gasbarre et al., 2009b) demon- steam flaked corn, chopped alfalfa hay, cottonseed culls, strated resistance in Haemonchus placei and Cooperia corn gluten feed, trace mineral supplement, molasses, fat, spp. to avermectins and milbemycin, specifically to mox- and micro-ingredients (e.g., feed additives and vitamins). idectin, doramectin, eprinomectin, ivermectin, as well as After preconditioning, animals were revaccinated with ® albendazole. Additionally the study found a small num- (Vista 5 ) and again treated for internal parasites in the ® ber of H. contortus resistant to both the macrocyclic feed (Safeguard pellet, fenbendazole, 5 mg/kg) for two lactones and the benzimidazoles. A follow-up study con- days. ducted the following year in greater detail using additional The calves were then moved to pens equipped with ® anthelmintics (Gasbarre et al., 2009a,b) found that lev- GrowSafe feeding nodes (Airdrie, Canada). These special- amisole was efficacious in removing the drug resistant ized feed bunks are designed to measure individual feed parasites. Subsequently, a drylot study (Edmonds et al., consumption in grams using individual animal electronic 2010) also demonstrated resistance of C. oncophora to identification for data capture. Feed bunks were designed injectable ivermectin and moxidectin. The recent NAHMS such that only a single animal could eat at a time, with four survey found resistance primarily to pour-on macrocyclic bunks/pen, allowing up to four animals to eat at a time lactones (Gasbarre et al., unpublished data), that often in each pen. The calves were given an additional week for ® resulted in a monoculture of Cooperia sp. in the treated acclimation to the GrowSafe system before the study was cattle. initiated. Because few studies have examined the effects of pure Calves were randomly divided into two treatment cultures of Cooperia sp. on productivity in beef cattle, the groups (control and infected) each with 80 calves. Each current study was designed to assess the effects of an treatment group was further divided into 2 replicated experimental C. punctata infection on feed intake, growth pens of 40 animals each.