Masters Theses

Date of Award

6-1976

Degree Type

Thesis

Degree Name

Master of Science

Major

Animal Science

Major Professor

J. B. McLaren

Committee Members

D. O. Richardson, M. C. Bell

Abstract

Three hundred and eighteen weanling steer calves purchased from cooperating Tennessee feeder-calf producers were used in four preliminary trials during 1974-75 and 1975-76 to investigate the use of industry cattle to study factors affecting the general health and performance of feeder calves subject to the stress of normal industry shipment procedures and to compare preconditioning procedures imposed at the farm of origin and at the first point of assembly in the transportation chain. In the first two trials, 80 calves were divided into four treatment groups which were vaccinated for blackleg, malignant edema, leptospirosis, infectious bovine rhinotracheitis, paraenfluenze-3 and pasturella at various times before and during shipment. One control group was not vaccinated and one group was weaned and fed concentrates for 20 days prior to shipping. The calves were shipped direct from the farm of origin to the Middle Tennessee or Highland Rim Experiment Station (180 miles). Various shipment and preconditioning procedure did not affect the health or subsequent performance of the steers in the feedlot. It was concluded that the effects of preconditioning treatment could not be evaluated unless the calves were exposed to sale-barn environment and to more shipping stress than was involved in these trials. In addition, it appeared that standardization of the concentrate ration fed during the preconditioning period was necessary for satisfactory results. During 1975-76, 238 calves were subjected to one of the following treatments (1) Control, not preconditioned and subject to normal industry shipment stress, (2) not preconditioned but fed a high-energy, high-antibiotic ration at the sale barn and/or order buyer assembly barn, (3) preconditioned, weaned 30 days prior to shipping and fed a commercial concentrate ration and (4) not preconditioned but loaded on the trucks near the farm of origin without being subjected to the sale-assembly barn stress. Eighteen calves each were subjected to treatments 1, 2, and 3, assembled at a commercial auction barn, held for 96 hours and shipped 600 miles enroute to the Highland Rim Experiment Station (HRES). Forty-six calves were subjected to each of the four treatments and hauled 1150 miles to a commercial feedlot in Kansas. Calves weaned and fed at the farm of origin tended to gain faster than those that nursed their dams, without supplemental feed, during the preconditioning period on the farm of origin. In addition, the responses to weaning and feeding on the farm of origin varied in the calves shipped to Kansas. This was due to differences among the ability of the cooperating producers to feed weanling calves and to variation in pasture quality and quantity among farms. These factors resulted in a significant (P<.01) farm-by-treatment interaction. It appears that this will be a problem in future studies if true samples of Tennessee beef cattle producers are obtained. Loss of weight during the first 24 hours in the sale barn (auction-sale barn environment) and total loss during the 96 hours (auction-sale and order-buyer assembly barn environment) was less for the cattle fed the high-energy high-antibiotic ration during this period. However, calves fed the concentrate ration at the assembly barn lost more weight during transit than those fed hay. Gain during the first 3 to 5 weeks in the feedlot was higher, death loss was less, and incidence of clinical respiratory disease was lower for calves fed a concentrate ration, either at the farm of origin or at,the first assembly point. This study suggest that weanling calves purchased from co operating feeder calf producers 30 days prior to shipment can be used to study shipping stress and factors affecting the incidence of clinical respiratory disease resulting from shipment. However, these calves must be subjected to sale-barn, assembly-barn, stress and/or exposed to bacterial or viral source of infection present in these barns if normal shipping problems are to be encountered with the control (not preconditioned and subjected to normal industry shipping procedure) cattle. Although, the number of observations (groups of calves) were not large enough to draw conclusion from this study, some consistent trends were observed in both of the 1975-76 trials. This study suggests also that improvement in the general health and/or feedlot performance may result from providing additional energy to calves for 30 days prior to moving them from the farm of origin or by providing a high-energy, high-antibiotic ration for 3-5 days at the first point of assembly. Future studies should include evaluation of supplemental energy and medication (feeding antibiotics or immunization against various pathogens) at the farm of origin and at the first assembly point, factors affecting truck stress and factors affecting sale barn stress.

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