Oklahoma State University beef nutritionists studied the effects of deworming and protein supplementation during late-summer on performance of fall-born heifers grazing native warm-season pastures.
Native range protein concentration falls below the requirements for growing cattle during summer and fall. Consequently, oilseed based protein supplements have been shown to consistently and efficiently improve performance of stocker cattle grazing native warm-season pastures during the late summer and autumn months . Gastrointestinal parasites are a major cause of economic loss in ruminants throughout the world. Ostertagiaostertagi is the major contributor to the loss. Well-controlled studies have documented the pathophysiology of gastrointestinal parasite infection in the ruminant, more specifically, ruminant nutrition. Previous reports have demonstrated increased summer weight gains when growing cattle were treated with an anthelmintic during mid- and late-summer. This study was designed to determine the effects of summer protein supplementation and anthelmintic treatment alone or in combination.
Forty Angus and Angus x Hereford heifers (average age = 270days) were assigned to receive one of four treatment combinations:
The dewormer treatment (Ivermectin, 1% solution containing 10% clorsulon) was applied on July 25 and again on August 26. Protein supplemented heifers received the equivalent of 1 pound per head per day of cottonseed meal (41% crude protein, as fed basis) for 84 days beginning on July 29. Fecal egg counts were obtained from 5 heifers within each treatment combination at 28-day intervals. Fecal egg shedding was lower in dewormed heifers throughout the treatment period.
Both protein supplementation and deworming treatment resulted in improved weight gains during the treatment period. Late summer de-worming increased average daily gain by 0.29 lb/day. Feeding 1pound of cottonseed meal increased average daily gain by 0.49 lb/day. Combining deworming and protein supplement increased daily gain by 0.76 lb/day.
The effects of protein supplementation and deworming are additive.However, some, although not all, of the additional weight gain due to supplementation was lost during the winter when heifers received a maintenance diet. Added weight gain that was attributed to deworming heifers the previous summer was not lost during the winter.