Ensiled high moisture corn stover as an alternative forage in gestating and lactating beef cow diets

Abstract Text:

The objective of this study was to evaluate ensiled high-moisture corn stover (HMCS) as an alternative forage in gestating and lactating beef cow diets. In exp. 1, multiparous Simmental and Angus x Simmental cows (n=96) in mid to late gestation were utilized. A randomized complete block design was used with cows blocked by BW. Dietary treatments were: 1) 60% HMCS, 25% ground cornstalks, and 15% corn gluten feed (STALK); 2) 60% corn silage, 25% ground cornstalks, and 15% corn gluten feed (SIL); and 3) 60% hay, 25% ground cornstalks, and 15% corn gluten feed (HAY). Diets were limit-fed from 108 ± 14 to 38 ± 14 d prepartum to achieve a DMI of 1.5% BW. In exp. 1, BW gain was greatest (P < 0.01) for cows fed SIL, intermediate for cows fed STALK, and least for cows fed HAY (63 kg vs. 34 kg vs. 17 kg). While all cows started and ended the trial in good body condition, cows fed SIL and cows fed STALK had a greater (P = 0.04) increase in BCS than cows fed HAY. Feed cost, in order from least to greatest, was STALK ($1.33·cow^-1·d^-1), HAY ($1.66·cow^-1·d^-1), and SIL ($1.68·cow^-1·d^-1). Manure analysis indicated no difference (P ≥ 0.17) in nitrogen, phosphorus, or potassium between treatments. In exp. 2, lactating Simmental and Angus x Simmental cows (n=79) were randomly allotted at calving to two treatments: 1) 75% HMCS, and 25% dried distillers grains (DDGS) on a DM basis (STALK2); and 2) 70% corn silage and 30% DDGS (SIL2). Diets were limit fed to achieve NRC requirements for maintenance and lactation; thus, cows fed STALK2 received 15.3 kg total DM, whereas cows fed SIL2 received 12.7 kg total DM. In exp. 2, BW gain was greater (P < 0.01) for cows fed SIL2 compared to cows fed STALK2 (32 kg vs. -6.0 kg). No differences (P ≥ 0.16) were detected in BCS change, milk production, or subsequent AI conception rates. Feed cost for cows fed STALK2 was calculated at $1.77·cow^-1·d^-1while SIL2 was calculated at $2.16·cow^-1·d^-1. Ensiled HMCS may serve as an alternative forage for feeding gestating beef cows. While lactating cows fed ensiled HMCS had poorer BW gain than cows fed corn silage, the reduced feed cost of HMCS warrants more investigation into its use in lactating beef cow diets.

Keywords:

alternative forage, beef cow, corn stover