Effect of supplemental fat from dried distillers grains with solubles or corn oil on cow performance, IGF-1, GH, and NEFA concentrations 1

Transcription

1 Effect of supplementl ft from dried distillers grins with solules or corn oil on cow performnce, IGF-1, GH, nd NEFA concentrtions 1 Aigil Brtosh 2, Cody Wright 3, Aimee Wertz-Lutz 4, nd George Perry 5 Deprtment of Animl nd Rnge Sciences BEEF 27-1 Summry Reserch hs demonstrted tht supplementl ft nd(or) chnges in growth hormone (GH) or insulinlike growth fctor-1 (IGF-1) concentrtions my ffect reproductive performnce in eef femles. Dried distillers grins with solules (DDGS) contin pproximtely 1% to 15% ft; however, miniml reserch to dte hs investigted DDGS specificlly s supplementl ft source. The ojective of this experiment ws to investigte whether supplementl ft from either DDGS or rw corn oil impcts cow growth performnce nd plsm GH, IGF-1, or non-esterified ftty cid (NEFA) concentrtions. Sixty open eef cows [ody weight (BW) = ± 38.7 kg; ody condition score (BCS) = 5.4 ±.53] were strtified y BW nd BCS nd llotted to 15 pens (n = 4 per pen; 14.6 x 37.2 m). Pens were rndomly ssigned to one of three dietry tretments: 1) DDGS, 2) comintion of high-protein dried distillers grin, corn rn, nd corn oil (OIL), or 3) comintion of high-protein dried distillers grin nd corn rn (HPBRAN). The DDGS, OIL, nd HPBRAN tretments ech comprised 35% of the diet dry mtter (DM). Thirty-five percent ws selected sed upon the sulfur (S) content of dietry ingredients in the DDGS tretment nd wter, estimted wter intke, nd the mximum tolerle S concentrtion for cttle on forge-sed diets (.5%). In ddition to dietry tretments, cttle were provided grss hy [7.7% crude protein (CP)] nd pelleted supplement contining vitmins nd minerls s prt of totlly mixed rtion. Cows were fed once dily, in the morning, for 6 d. All diets were iso-nitrogenous (15.3% CP from d to 47 nd 15.1% from d 48 to 6) nd totl ft concentrtions were 5.1% for DDGS nd OIL nd 3.5% for HPBRAN. Weights nd lood smples were recorded prior to feeding on d -1,, 28, 59, nd 6. Dry mtter intke, verge dily gin, finl BW, nd gin:feed were not ffected y tretment. Tretment hd no effect on plsm GH, IGF-1, or NEFA concentrtions. These results suggest tht providing low concentrtions of supplementl ft s DDGS or rw corn oil to forge-sed diet does not influence growth performnce, plsm GH, IGF-1, or NEFA concentrtions in open eef cows. Introduction Supplementl ft hs een shown to increse serum growth hormone (GH) concentrtions in eef cttle (Willims nd Stnko, 2). The increse in GH coincides with n increse in folliculr fluid insulin-like growth fctor-1 (IGF-1) concentrtions, wheres peripherl IGF-1 levels re not ffected. Accumultion of folliculr fluid IGF-1 hs een proposed s one of the mechnisms ssocited with follicle selection. Reserchers hve hypothesized tht these chnges in hormone concentrtions my e ssocited with unsturted fts (Willims nd Stnko, 2). Dried distillers grins plus solules (DDGS) re co-product of the ethnol industry. Survey reserch suggests tht distillers grins contin pproximtely 1.8% ft (Shurson, 26). Furthermore, corn oil is high in unsturted ftty cids (Griinri et l., 1998). Under norml circumstnces, unsturted ftty cids tht re introduced into the rumen re iohydrogented to more sturted ftty cids. However, recent reserch suggests tht the ft contined in distillers grins my e somewht protected from iohydrogention in the rumen (Koger et l., 24; Vnder Pol et l., 24). University of Nersk 1 This project ws funded y the South Dkot Corn Utiliztion Council nd portion of the co-products were provided y Dkot Gold Reserch Assocition. 2 Grdute Student. 3 Associte Professor/Extension eef specilist. 4 Assistnt Professor ruminnt nutrition. 5 Assistnt Professor/Extension Beef Reproductive Mngement Specilist. 1

2 reserchers reported decresed feedlot performnce when 5% ft ws included s corn oil, ut no ffect ws oserved when 5% ft ws included s wet distillers grins (Vnder Pol et l., 24). These dt suggest tht the lipids contined in corn oil or distillers grins my e metolized differently nd elicit different production responses. Reserchers t South Dkot Stte University exmined the effect of 2% or 4% wet or dry distillers grins on the ftty cid composition of the longissimus muscle of steers (Koger et l., 24). The reserchers found tht muscle tissue from cttle fed either wet or dry distillers grins contined higher concentrtions of unsturted ftty cids. Together, these dt suggest tht the unsturted fts contined in distillers grins my escpe rumen iohydrogention nd my e sored in n unsturted form. The current experiment ws designed to compre the effect of supplementl ft s either DDGS or rw corn oil on cow performnce nd plsm GH, IGF-1, nd non-esterified ftty cid (NEFA) concentrtions. Mterils nd Methods Sixty open eef cows were purchsed from pulic uction mrkets nd trnsported to the Southest Reserch Frm locted ner Beresford, SD. Initil ody weights (BW; ± 77.4 l) were recorded nd initil ody condition score (BCS; 5.4 ±.53) were determined s the verge of two experienced evlutors. Cows were strtified y BW nd BCS nd llotted to 1 of 15 pens. The cows were provided with medium-qulity grss hy d liitum for minimum of 14 d prior to tril initition; fter which the pens were rndomly ssigned to one of three dietry tretments. The first dietry tretment (DDGS) ws comprised solely of DDGS nd contined pproximtely 15% dietry crude protein (CP) nd 5% dietry ether extrct (EE). The second dietry tretment (OIL) contined high-protein dried distillers grins (HP DDG), corn rn, nd corn oil to provide the sme mount of CP nd EE s the DDGS diet. The finl tretment (HPBRAN) ws formulted provide the sme mount of protein, ut no dditionl ft; dietry ingredients included HP DDG nd corn rn (Tle 1). Tle 1. Composition of tretment diets Tretments Item DDGS OIL HPBRAN % of diet DM Hy Supplement DDGS HP- DDG c Corn rn Corn oil Anlyzed nutrient composition Dry mtter Crude protein Ether extrct Sulfur Provides vitmins nd minerls to meet or exceed nutrient requirements (Nutrient Requirements of Beef Cttle, Ntionl Reserch Council, 2). Dried distillers grins with solules. c High-protein dried distillers grins. Dietry CP fed in this experiment (15%) is sustntilly more thn these cows require; diets were formulted to provide the mximum mount of ft from distillers s possile without cusing helth prolems due to sulfur (S) intke. Minerl Tolernces of Animls sttes the mximum tolerle S concentrtion for cttle on forge-sed diets s.5%. Dily wter intke ws estimted to e 7 gl/d 2

3 nd ville wter nd ll feed ingredients were nlyzed to determine S content prior to tril initition. Cows were fed totlly mixed rtion which consisted of the dietry tretment, medium-qulity grss hy nd vitmin/minerl supplement to meet or exceed the cows minerl requirements s suggested y the NRC (2). Weights were recorded on 2 consecutive d prior to tril initition nd t tril termintion nd one dy ner the midpoint of the tril. Blood smples were collected on d, 28, nd 6. Growth hormone nd IGF-1 concentrtions were nlyzed using rdioimmunossy. Non-esterified ftty cid concentrtions were nlyzed using colorimetric ssy. Cow performnce dt were nlyzed using the PROC GLM method of SAS with pen s the experimentl unit. Plsm GH, IGF-1, nd NEFA dt were nlyzed s repeted mesures using the mixed procedure of SAS with pen s the experimentl unit. Results nd Discussion Cow performnce dt re presented in Tle 2. Dietry tretments hd no effect on niml performnce. Cows consumed 2.4 to 2.6% of their ody weight nd gined 1.2 to 1.3 kg per hed per dy. Tle 2. Cow growth performnce. Tretment Item DDGS OIL HPBRAN SEM P-vlue DMI, l ADG, l G:F Tle 3. Plsm GH, IGF-1, nd NEFA concentrtions. Tretment Item DDGS OIL HPBRAN SEM P-vlue GH, ng/ml IGF-1, ng/ml NEFA, µeq/l Plsm GH, IGF-1, nd NEFA concentrtions were not ffected y tretment y time interctions. Tle 3 shows the min effect of tretment on the hormone nd NEFA concentrtions. Figures 1, 2, nd 3 illustrte the min effect of time on plsm GH, IGF-1, nd NEFA, respectively. Plsm IGF-1 concentrtion ws greter (P <.1) on d 6 thn on d or 28 (Figure 1). From d to d 28, plsm GH concentrtion decresed (P <.13); concentrtions on d 28 nd d 6 were similr (Figure 2). Plsm NEFA concentrtion decresed (P <.1) from d to d 28; concentrtions on d 28 nd d 6 were not different. This decrese in plsm NEFA concentrtions is likely the result of the grss hy diet the cows were fed prior to the initition of the experiment. It is possile tht the grss hy ws not meeting the energy demnds of the cows, nd consequently, they were moilizing ody ft stores to meet their energy needs. Then, once the experiment egn nd the plne of nutrition ws incresed, the circulting NEFA concentrtions decresed in similr pttern to tht of GH. 3

4 Plsm IGF-1, ng/ml , P < Dy Plsm GH, ng/ml , P < Dy Plsm NEFA, ueq/l , P < Dy FIGURES 1, 2, 3 4

5 Implictions This experiment suggests tht, when totl dietry ft concentrtions re equl to or elow 5.1%, supplementl ft from either DDGS or corn oil does not impct growth performnce or plsm GH, IGF-1, or NEFA concentrtions in open eef cows. Literture Cited Griinri, J. M., D. A. Droyer, M. A. McGuire, D. E. Bumn, D. L. Plmquist, nd K. V. V. Nurmel Trns-Octdecenoic cids nd milk ft depression in lctting diry cows. J. Diry Sci. 81(5):1251. Koger, T. J., D. M. Wulf, K. E. Tjrdes, K. S. Mteo, T. E. Engle, C. L. Wright, nd R. J. Mddock. 24. The influence of feeding vrious levels of wet nd dry distiller grins on crcss qulity, crcss composition, nd ftty cid profile of finishing steers. Proc. 57th Recip. Met Conf., University of Kentucky. Shurson, 26. Proximte nlysis of DDGS. Accessed: July 26, 27. Vnder Pol, K. J., G. E. Erickson, T. J. Klopfenstein, nd C. N. Mcken. 24. Effect of wet nd dry distillers grins plus solules nd supplementl ft level on performnce of yerling finishing cttle. Pges 45-48, Nersk Beef Report. University of Nersk, Lincoln. Willims, G. L., nd R. L. Stnko. 2. Dietry fts s reproductive nutrceuticls in eef cttle. Aville: Accessed Sept. 2, 26. 5