Comparison of Low-Input Pasture to High-Input Drylot Backgrounding on Performance and Profitability of Beef Calves Through Harvest

Professional Animal Scientist, Apr 2008 by Mathis, C P, Cox, S H, Löest, C A, Petersen, M K, Endecott, R L, Encinias, A M, Wenzel, J C

ABSTRACT

Over 3 yr, 250 calves (236 kg initial BW; 133 steers and 117 heifers) were used to compare a low-input pasture backgrounding system (PAST) to a high-input drylot system (DLOT) to evaluate performance and profit during the backgrounding (BACKGRD; weaning to 42 to 45 d) and finishing (FINISH; end BACKGRD to slaughter) phases. Calves were randomly assigned to PAST or DLOT treatments during BACKGRD. The DLOT calves were fed a corn-wheat midds-based pellet plus alfalfa hay (0.68 to 1.13 kg/d), and PAST calves were supplemented with a 32% CP range cube (0.57 kg/d; 3 times/wk). During BACKGRD, DLOT calves gained more BW (P

Key words: backgrounding, beef calf, feedlot, profit, health

INTRODUCTION

The Texas A&M University Value Added Calf (VAC) guidelines (Anonymous, 2005) originally established weaning duration recommendations based upon Texas Ranch to Rail calf health records that indicated a decline in medicine cost and morbidity among calves weaned 45 d or more prior to transportation to a feedyard. Industry acceptance of the 45-d duration as a component of a backgrounding system is evident in current price premiums. From 2000 to 2004, price premiums for "VAC-45" calves marketed through Superior Livestock Auction video sales increased every year, with annual average premiums ranging from $3.66 to $7.91/45.4 kg (King and seeger, 2005). Justification for such premiums are supported by the analysis of New Mexico Ranch to Rail data (Waggoner et al., 2005), which showed that steers weaned 41 d or more before feedlot entry generated $22 and $44 per head more net income during finishing than steers backgrounded 21 to 40 d or less than 20 d, respectively. Those findings further support the premise that backgrounding programs of 45 d or more on the ranch of origin improve finishing profit potential.

Even though backgrounding calves for 45 d or more is commonly practiced, studies evaluating backgrounding have typically focused on programs less than 40 d (Pritchard and Mendez, 1990; Roeber et al., 2001; St. Louis et al., 2003), and controlled experiments evaluating the impact of divergent backgrounding systems on performance and profit through harvest are limited. Therefore, this study compared a low-input pasture backgrounding system to a high-input drylot system of the same duration to evaluate performance and profit during the backgrounding and finishing phases.

MATERIALS AND METHODS

Over 3 yr, 250 calves (236 kg average initial BW; 133 steers and 117 heifers) were used to compare 2 backgrounding systems at the New Mexico State University Corona Range Livestock Research Center (CRLRC) located 13 km east of Corona, NM (average elevation = 2,000 m; average annual precipitation = 380 mm). All animal handling and experimental procedures were in accordance with guidelines established by the New Mexico State University Animal Care and Use Committee. Calves originated from the CRLRC spring-calving British-crossbred cow herd and were born in February, March, or April of 2003, 2004, and 2005.

Steer calves were castrated at branding (early May). At branding and 16 to 21 d prior to weaning, all calves were vaccinated against bovine respiratory syncytial virus, infectious bovine rhinotracheitis, bovine viral diarrhea, and parainfluenza 3 (yr 1 with Bovi-Shield 4; yr 2 and 3 with BoviShield Gold 5; Pfizer Animal Health, Exton, PA), and were administered a 7-way clostridial vaccine (Ultrabac-7, Pfizer Animal Health).

Backgrounding Phase

All BW were measured unshrunk at the same time of day, and a 4% pencil shrink was applied. At weaning (d 0), calves were weighed, assigned a market price, and randomly assigned to 1 of 2 treatments: 1) high-input drylot backgrounding system (DLOT) or 2) low-input pasture backgrounding system (PAST). Each treatment was replicated within year. Following vaccination and measurement of weaning BW, calves were transported to their respective pen or pasture. Prior to weaning, calves were not all in the same pasture; therefore, calves from different pastures were commingled when sorted into treatment pen or pasture. The same 2 native range pastures (minimum 4.1 ha/ head) and drylot pens (minimum 17.8 m^sup 2^/head) were used each year. During yr 1, water sprinklers were utilized to minimize dust in drylot pens; however, dust control was not necessary during yr 2 and 3. Free choice access to water and a loose mineral mix (38% NaCl, 12% Ca, 8% P, 2% K, 2% Mg, 2,500 ppm Mn, 1,000 ppm Cu, 1,000 ppm Zn, 13 ppm Se, and 125,000 IU/kg vitamin A; Hi-Pro Feeds, Friona, TX) was provided.

Native range pastures were not grazed during the spring and summer growing season prior to stocking during backgrounding. Predominant grass species include blue grama (Bouteloua gracilis), threeawn (Aristida spp.), and wolftail (Lycurus phleoides; Forbes and Allred, 2001). Average annual forage production at the study site is 1,000 kg/ha (G. B. Donart, New Mexico State University, Las Cruces, personal communication). Forage availability exceeded cattle needs during all 3 yr. To estimate forage quality, grass samples were annually hand-plucked (Wallace de Vries, 1995) from pastures at the end of the backgrounding period, and analyzed for CP, NDF, and ADF at a commercial laboratory (Table 1; SDK Laboratories Inc., Hutchinson, KS).