Restricting bunk space allotments to 15 or 25 centimeters per head has minimal effects on growth performance in limit-fed growing beef heifers

Abstract

Objective

Our objective was to evaluate the effects of bunk allotment on growth performance of receiving beef heifers limit fed a diet based on high-energy corn and corn co-products, in pens that contained 18 to 28 heifers.

Materials and Methods

Beef heifers (291 ± 15.5 kg; n = 332) were used in a randomized complete block design. Heifers were blocked by origin, stratified by indi- vidual arrival weight, and assigned to pen within block. Pens were randomly assigned to 1 of 4 treatments, with 4 pens per treatment, that provided 15.2, 25.4, 35.6, or 45.7 cm of linear bunk per heifer. Heifers were limit fed a high- energy diet once daily at 2.0% of BW (DM basis) for 56 d. Individual BW were measured on d 0 and 56. Pen BW were measured weekly and used to adjust feed delivered for the following week.

Results and Discussion

Bunk allotments of 15.2, 25.4, 35.6, or 45.7 cm per heifer did not affect final BW, ADG, DMI, or G:F. At feeding, 43%, 62%, 79%, and 96% of heifers in the pen had access to the feed bunk when allotted 15.2, 25.4, 35.6, and 45.7 cm of linear bunk per heifer, respectively. The SD of ADG within the pen did not differ among feed bunk sizes.

Implications and Applications

Bunk allotments as low as 15.2 to 25.4 cm per heifer can be used without negatively influencing growth performance of growing beef heifers of about 290 to 360 kg of BW that are limit fed a high-energy diet at 2.0% of BW (DM basis) once daily in pens that contained 18 to 28 head.