The cost of feeding bred dairy heifers on native warm-season grasses and harvested feedstuffs

Abstract

Heifer rearing is one of the largest production expenses for dairy cattle operations, which is one reason milking operations outsource heifer rearing to custom developers. The cost of harvested feedstuffs is a major expense in heifer rearing. A possible way to lower feed costs is to graze dairy heifers, but little research exists on this topic in the mid-south United States. The objectives of this research were to determine the cost of feeding bred dairy heifers grazing native warm-season grasses (NWSG), with and without legumes, and compare the cost of grazing with the cost of rearing heifers using 3 traditional rations. The 3 rations were corn silage with soybean meal, corn silage with dry distillers grain, and a wet distillers grain-based ration. Bred Holstein heifers between 15- and 20-mo-old continuously grazed switchgrass (SG), SG with red clover (SG+RC), a big bluestem and Indiangrass mixture (BBIG), and BBIG with red clover (BBIG+RC) in Tennessee during the summer months. Total grazing days were calculated for each NWSG to determine the average cost/animal per grazing day. The average daily gain (ADG) was calculated for each NWSG to develop 3 harvested feed rations that would result in the same ADG over the same number of grazing day as each NWSG treatment. The average cost/animal per grazing day was lowest for SG ($0.48/animal/grazing d) and highest for BBIG+RC ($1.10/animal/grazing d). For both BBIG and SG, legumes increased the average cost/animal per grazing day because grazing days did not increase enough to account for the additional cost of the legumes. No difference was observed in ADG for heifers grazing BBIG (0.85 kg/d) and BBIG+RC (0.94 kg/d), and no difference was observed in ADG for heifers grazing SG (0.71 kg/d) and SG+RC (0.70 kg/d). However, the ADG for heifers grazing SG and SG+RC was lower than the ADG for heifers grazing either BBIG or BBIG+RC. The average cost/animal per grazing day was lower for all NWSG treatments than the average cost/animal per day for all comparable feed rations at a low, average, and high yardage fee. Results of this study suggest that SG was the most cost-effective NWSG alternative to harvested feeds for bred dairy heifer rearing.

Risk and returns from grazing beef cattle on warm‐season grasses in Tennessee

“…Similarly, animal performance and economics of grazing bred heifers on WSG have proven favorable with cost of gain as low as $0.14 kg −1 for switchgrass ( Panicum virgatum L.; SG) pasture and $0.18 kg −1 when a combination of big bluestem ( Andropogon gerardi Vitman) and indiangrass ( Sorghastrum nutans L.; BI) was grazed (Keyser et al., ). Furthermore, costs for dairy heifers grazing SG and a BI blend were $0.38 and $0.65 head −1 d −1 , which are lower than the $1.89 head −1 d −1 that was estimated for using harvested commodity feeds (Lowe et al., ).…”

“…One possible solution to this problem is to graze WSGs during summer. While several studies have examined animal performance on WSGs in the southeastern United States, only a few studies have compared the profitability of these forages (Backus et al., ; Burns & Fischer, ; Burns et al., ; Lowe et al., , ). More research is needed to determine WSG species or mixtures that best fit the southeastern United States.…”

“…For the perennial forages, a 10-yr production horizon with no grazing in the establishment year was assumed, which is typical for this region (Boyer, Tyler, Roberts, English, & Larson, 2012Lowe et al, 2015;Zhou, Boyer, Larson, & Lieb, 2014). Total establishment and production costs of native warm-season grasses were calculated following previous studies (Boyer, Griffith, Roberts, Savoy, & Leib, 2014;Keyser et al, 2016;Lowe et al, 2015Lowe et al, , 2016McFarlane, Boyer, & Mulliniks, 2018). Establishment costs, which included seed, fertilizer, herbicide, machinery, and labor, were annualized over the pasture production life using a discount rate of 5.5% (Boyer et al, 2012Lowe et al, 2015;McFarlane et al, 2018;Zhou et al, 2014).…”

“…For these reasons, several studies have analyzed animal performance on WSGs in the southeastern United States, and have found that steers grazing WSGs have positive gains (Backus et al., ; Burns & Fischer, ; Burns, Mochrie, & Timothy, ; Lowe et al., , ). However, only a few existing studies have examined the profitability of grazing WSG.…”

Eastern grasslands: Conservation challenges and opportunities on private lands

“…Research is accumulating that demonstrates that NWSGs have many compelling attributes that can contribute to more sustainable forage production in the Fescue Belt. For example, animal performance is strong (0.80–0.95 kg/day average daily gains; Keyser et al , Backus et al ), and yields are high (9–11 Mg DM/ha; Olson et al , McIntosh et al ), with consistently positive economic returns (Lowe et al , ; Monroe et al ). In addition, use of NWSGs, which do not have toxicity issues, during summer could reduce cattle exposure to fescue toxins while improving drought resiliency (Buttrey et al , Burns and Fisher , Caldwell et al ).…”