Effects of dried distillers grains and equivalent undegradable intake protein or ether extract on performance and forage intake of heifers grazing smooth bromegrass pastures1

Abstract

Crossbred heifers (n = 120; BW = 368 kg, SD = 39 kg) were used to determine effects of dried distillers grains (DDG) and relative contributions of undegradable intake protein (UIP) and fat (ether extract, EE) in DDG on ADG and forage intake (FI). Heifers rotationally grazed six 3.5-ha, smooth bromegrass paddocks (IVDMD = 65.7%, CP = 20.8%, UIP = 2.17%, DM basis). Heifers were blocked by previous ADG and allotted to treatments in a 3 × 3 + 1 factorial design. Factors were source and level of supplementation. Supplements were as follows: 1) DDG (UIP = 15.8%, EE = 9.67%), 2) corn gluten meal (CGM; UIP = 31.6%, EE = 0.83%), or 3) corn oil (OIL; UIP = 0.74%, EE = 19.3%). Amounts of DDG were 750, 1,500, or 2,250 g/d, whereas amounts of CGM and OIL were 375, 750, or 1,125 g/ d. Supplements containing CGM and OIL were fed in amounts that provided UIP and EE, respectively, equivalent to those of the DDG. Contrasts of interest were DDG vs. CGM and DDG vs. OIL. Control heifers were fed 250 g/d of a supplement containing corn bran and molasses (UIP = 0.92%, EE = 1.13%). Heifers were supplemented individually. Treatments were separated by regressing the response variables on grams of nutrient

Smooth bromegrass pasture beef growing systems: Fertilization strategies and economic analysis

“…This increase in weight gain can be attributed to the undegradable intake protein (UIP) and additional energy, from both fat and digestible fiber, provided by the DDGS because pasture in vitro DM digestibility (IVDMDig) did not differ among treatments (P = 0.71; Table 2). This would agree with MacDonald et al (2007) who found that heifers grazing pasture had increased gains when supplemented with distillers grains compared with heifers supplemented with either corn gluten meal or corn oil. Morris et al (2005) reported increased gains of 0.20 kg/d for each kilogram of DDGS supplemented to heifers on a 65% TDN forage diet.…”

CASE STUDY: In situ determination of protein digestibility of dried distillers grains containing 3 lipid concentrations using a mobile bag method

“…This indicates variability in experimental conditions or the CSM itself as supported by Goetsch and Owens (1985). MacDonald et al (2007) obtained CP values of DDGS that support the current study's values, but RUP (51.3%) and TTIDP (57.0%) were lower and RUPDIG (88.8) was higher than in the current study. As demonstrated in this study, RDP (% of DM) in DDGS can be affected by lipid level, and the differences in TTIDP and RUPDIG observed in the current experiment compared with others may be due to variability of DDGS explained by Spiehs et al (2002) and Klopfenstein et al (2008).…”

“…Of the 10 in situ bags of each sample incubated per steer, 4 were used for determination of RUP (% of CP) and 6 for determination of RUPDIG. One mesh bag containing 40 in situ bags (10 of each ingredient so that every ingredient was incubated in every steer) was placed in the ventral sac of the rumen of each steer and incubated for 16 h. An incubation of 16 h has been commonly used for determination of RUP of concentrate feeds (Kopečný et al, 1998;MacDonald et al, 2007). After incubation, mesh bags were lightly rinsed in water to remove excess ruminal fluid.…”

Dried distillers grains as a substitute for grazed forage

“…A lack of difference in forage disappearance between the 2 double-stocked treatments suggests the DDG did not replace forage. MacDonald et al (2007) found a forage replacement rate of almost 50% when DDG was supplemented to heifers grazing smooth brome pastures at rates ranging from 0.75 to 2.25 kg/d. Extrapolating the finding of MacDonald et al (2007) to the present experiment suggests feeding 2.27 kg/d per animal of DDG would only replace 1.14 kg/d per animal of forage.…”

“…However, ethanol production from corn grain has made dried distillers grains (DDG) an available feedstuff that improves growth rate of grazing cattle (Griffin et al, 2012). In addition to demonstrating an increase in animal performance, previous research has demonstrated a substitution effect on forage intake when DDG is fed in forage-based diets (Loy et al, 2007;MacDonald et al, 2007;Griffin et al, 2012). If the cost of DDG is less than the cost of replaced grazed forage on a per unit of energy basis, then cost of production could be decreased by feeding DDG.…”