FOOD ANIMAL ECONOMICS - USE OF PERFORMANCE RATIOS TO CALCULATE THE ECONOMIC-IMPACT OF THIN COWS IN A BEEF-CATTLE HERD

Objective-To determine gross income lost that was attributable to thin cows in a beef cattle herd, to estimate the cost of added nutrition n ecessary to prevent thin cows in the herd, and to determine the financ ial outcome of the improved nutritional practices. Design-Prospective, observational study. Animals-Four hundred twenty-two Santa Gertrudis cows and their calves. Procedure-At pregnancy examination in the fail of 1992, cows were assigned a body condition score (BCS), using a scal e of 1 (emaciated) to 9 (obese), and the ratio of the productivity of BCS-3 and BCS-4 cow groups (thin cows), compared with the mean product ivity of BCS-5 and BCS-6 cows (cows in good condition), was determined . Measures of productivity evaluated included pregnancy rates, weaning weights, and prices per hundredweight of calves. The performance rati os of BCS-3 and BCS-4 cows were multiplied by the mean gross income of BCS-5 and BCS-6 cows to calculate their gross income. This was then s ubtracted from the mean income of BCS-5 and BCS-6 cows to estimate the amount of lost gross income per thin cow. The cost of a nutritional p rogram that would prevent thin cows in the herd was subtracted from th e lost gross income of the thin cows to yield the amount of increased net income that could be generated from a nutritional program that wou ld maintain cows in the herd at a BCS of 5 or 6. Results-Cows with a s cs of 3 were 0.48 as productive, and cows with a scs of 4 were 0.74 as productive-as the average of the BCS-5 and BCS-6 cows combined. Each BCS-3 cow generated $215.06 less, and each BCS-4 cow generated $107.53 less gross income than the average gross income of BCS-5 and BCS-5 co ws. The added cost of nutrition that would have reconditioned BCS-3 an d BCS-4 cows to a scs of 5.5 was $91.48/BCS-3 cow and $43.67/ BCS-4 co w. Implementation of the reconditioning nutrition program the previous fall would have resulted in an extra net income of $123.58/BCS-3 cow and $63.86/BCS-4 cow, received over a 2-year period. The 262 thin cows in the herd accounted for a total net income loss of $19,897. Clinica l Implications-The time of pregnancy examination is a strategic interv ention point to estimate the past negative economic impact of thin cow s and to implement a plan to prevent these losses in the future. Pregn ancy examinations should be performed at least 100 days before the beg inning of the carving season, and thin pregnant cows should be sorted into a special group and fed a reconditioning diet that will improve t heir body condition to an average scs of 5.5 by the onset of the calvi ng season.