Restricted feeding improves performance of growing steers during subsequent grazing on native flint hills pasture

Beef stocker operators are margin-operators, and rising feed costs force them to consider alternative feeding strategies to reduce production costs. Limit-feeding is a management technique that has positive implications for cost control. In this experiment, we restricted dry matter intake to determine if steers could compensate for a period of dietary restriction during intensive early grazing. This study illustrated that limit-feeding could reduce feed costs for stocker and background operators.


Introduction
Beef stocker operators are marginoperators, and rising feed costs force them to consider alternative feeding strategies to reduce production costs.Limit-feeding is a management technique that has positive implications for cost control.In this experiment, we restricted dry matter intake to determine if steers could compensate for a period of dietary restriction during intensive early grazing.This study illustrated that limit-feeding could reduce feed costs for stocker and background operators.

Experimental Procedures
Three loads of highly stressed, crossbred calves (n = 329; body weight = 420 lbs) were weighed and tagged on arrival at the Kansas State University Beef Stocker Unit.Calves were given a metaphylactic antibiotic (Draxxin1 ), vaccinated for clostridial and viral diseases, and de-wormed; bulls were castrated, and all animals were fed the Base 1 ration (Table 1).Following processing, steers from each load were placed in a row of eight pens divided into two blocks with four pens in each block.Steers were randomly assigned to pens and treatments within a block.Treatments consisted of a control group (full-fed) and steers restricted to dry matter intakes of 2.50, 2.25, or 2.00% of body weight.Steers were fed the same diet two times daily.Two stepup rations, Base 1 and 2 (Table 1), were fed for 18 days before treatments began.Steers were weighed at 14 day intervals, and intakes of restricted treatments were adjusted according to body weight on days 30, 45, and 62. Final weights with common gut-fill were measured on day 67.
On day 67, steers were de-wormed, implanted with Ralgro2 , and allotted by weight and treatment to burned, native tallgrass pastures with equal stocking densities.Each treatment group was evenly distributed in each pasture.Steer weights were measured 45 and 90 days after turn out.Steers were placed in the previous pens for five days and fed Base 1 at 2.00% of body weight (Table 1) to equalize gut-fill.

Results and Discussion
Average daily gain (ADG) of steers fed free choice was 28, 32, and 51% higher than steers fed 2.50, 2.25, and 2.00% of body weight, respectively.The ADG of steers fed 2.50 and 2.25% of body weight was similar (P>0.05) at the conclusion of the drylot phase.When compared with all other treatments, steers fed 2.00% of body weight had the lowest gains during the drylot period.Feed:Gain was more desirable for steers restricted to 2.50 or 2.25% of body weight compared with steers fed free choice or at 2.00% of body weight.Steers fed at 2.00% of body weight had poorer feed conversion efficiency than steers in any other treatment.Overall, steers fed freechoice cost 25% more (P<0.01)than steers that were limit-fed (Table 2).
Steers fed free choice had the poorest gains during the first 45 days of grazing; those fed at 2.00% body weight had the greatest gains (P<0.05).Animal performance tends to suffer during the second 45 days of grazing due to declining forage quality.Daily gains for all treatments were numerically lower dur-ing this period.Steers fed free-choice had the poorest daily gains overall during grazing.Final weights for steers fed free-choice, 2.50, and 2.25% body weight after grazing were not different (P>0.05);however, steers fed 2.00% body weight still had the smallest final weights of all treatments.

Implications
Limit-feeding in the drylot phase of stocker or background operations can decrease feed costs and increase performance of steers during subsequent grazing compared with fullfeeding in the drylot phase.