Rumen inert fat supplements reviewed for dairy cows

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1 Mrch 14, 2005 Volume 77, Numer 11 REPRINT Rumen inert ft supplements reviewed for diry cows The mode of ction for reduced intke when using clcium slts of ftty cids ppers to e primrily due to negtive effects of gstrointestinl motility, rumen function nd pltility, in tht order. Reduced intke ffects the mount nd durtion of negtive energy lnce in erly lcttion, susequent milk production nd reproduction nd economic vlue. By L.C. SOLORZANO nd A.F. KERTZ This review is primrily sed on the recent puliction y Loften nd Cornelius (2004). Rumen inert (i.e., not eing significntly chnged in the rumen or hving significnt effect on rumen function) fts re currently eing used throughout the U.S. nd other countries of lctting diry cow rtions. The min purpose in their use is to increse energy density nd milk production, ut reported responses rnge from none to vrily positive effects on milk components nd reproductive efficiency. The purpose of this rticle is to review literture nd to provide clerer nd more concise picture of the three min types of rumen inert fts nd their effects on milk production, milk components nd reproductive efficiency nd, most criticlly, on dry mtter intke (DMI). The three min ctegories of rumen inert fts used in lctting cow rtions tody re: prtilly hydrogented tllow (PHT), clcium slts of ftty cids (CSFAs) nd hydrogented free ftty cids (FFAs). These ft compounds were developed to enhnce the use of fts y Dr. L.C. Solorzno is with Milk Specilties Co., Dundee, Ill. Dr. A.F. Kertz is with ANDHIL LLC, St. Louis, Mo. TABLES 1. Effects of feeding FFAs nd CSFAs to lctting diry cows on milk production nd milk components; mens re differences etween FFAs nd CSFAs (FFA-CSFA) Author No. of cows Milk, l./dy FCM, l./dy Ft, % Protein, % Grummer, Schuff nd Clrk, Schuff nd Clrk, Wu et l., Elliott et l., Hrvtine nd Allen, Hrvtine nd Allen, Weighted men Effects of feeding FFAs nd CSFAs to lctting diry cows on DMI, ftty cid digestiility nd odyweight chnges; mens re differences etween FFAs nd CSFAs (FFA-CSFA) DMI, l. Ftty cid Bodyweight chnge, Author No. of cows per dy digestiility, % l. per dy Grummer, NA Schuff nd Clrk, NA NA Schuff nd Clrk, NA NA Plmquist, NA NA Wu et l., Elliott et l., NA Hrvtine nd Allen, c NA 0.68 Hrvtine nd Allen, NA Weighted Mens No. of cows in men Dt corrected for one cow tht hd low vlue. FFA nd CSFA comprison mde t 680 g dily intke of ech ft source. Digestiilities were 87.4 nd 84.9% for CSFAs nd FFAs, respectively. The 910 g dily intke tretment for FFAs resulted in digestiility of 87.2%. Using mrginl digestiility mesurements from Grummer (1998), ech 100 g dditionl ft intke should result in 2.8% lower digestiility. Using 910 g versus 680 g of FFAs, digestiility t 680 g should e greter thn 90% [( ) = 230/100 = 2.3 x 2.8 = = 93.64% digestiility t 680 g FFA intke]. However, the correction in Grummer s study ws used in this Tle. NA indictes dt not ville in pper. c 3. Effects of CSFAs nd sturted fts fed to lctting diry cows on DMI, 4% FCM, milk components nd odyweight chnge; mens re differences etween control nd CSFA or sturted fts DMI, l. 4% FCM, l. BW chnge, Tretment No. of cows per dy per dy Ft, % Protein, % l./dy CSFA Sturted fts Effects of CSFAs nd hydrogented ft on DMI, expressed s percent DMI depression for ech 1% dded ft to the rtion dry mtter ove control rtion Tretment No. of mens DMI, % reduction Significnce CSFAs P < Hydrogented ft P = Feedstuffs. Reprinted with permission from Vol. 77, No. 11, Mrch 14, 2005.

2 2 FEEDSTUFFS, Mrch 14, 2005 chemiclly ltering them to e used in dry form, thus providing diry producers with more functionl physicl form nd fcilitting on-frm hndling. PHT ws the first genertion of rumen inert fts. They re produced y hydrogenting tllow or vegetle fts to increse the melting point of the end product. Tllow or vegetle fts my contin s much s 85% unsturted ftty cids prior to hydrogention nd s little s 15% fter the hydrogention process. The iodine vlue, which is n indictor of the degree of unsturtion, cn vry from 14 to 31 (NRC, 2001). Hydrogention of tllow nd vegetle fts reduces negtive effects ftty cids hve on rumen fermenttion. However, the sme process severely reduces the digestiility of the end product nd its potentil for vlue in lctting diry cow rtions (Weiss nd Wytt, 2004). Elliott et l. (1994; 1999) found tht resistnce to ruminl nd smll intestinl lipolysis ws mjor fctor contriuting to the poor digestiility of highly sturted triglycerides contined in hydrogented tllow. CSFAs were the second genertion of rumen inert fts. Plm oil, soyen oil or other ft sources re hydrolyzed nd rected with clcium to form slts, which increses the melting point of the end product. Ftty cids of clcium slts re stle in the rumen t ph greter thn 6.5 (Sukhij nd Plmquist, 1990). However, Enjlert et l. (1994), Vn Nevel nd Demeyer (1996), Ferly et l. (1993) nd Wu et l. (1991) found tht unsturted ftty cids of CSFAs re extensively hydrogented in the rumen. This indictes tht dissocition occurs when the ph drops elow 6.5 fter mel or when mnipulting ph in vitro. These reserchers oserved tht up to 57% of CSFAs were, in fct, iohydrogented. Since Hwke nd Silcock (1969) found tht free croxyl group of ftty cids is required for iohydrogention to occur, CSFAs hve to dissocite prior to iohydrogention. This indictes tht CSFAs my not e s rumen inert s previously thought nd my e deleterious to rumen fermenttion nd possily to DMI. FFAS were the third genertion of rumen inert fts. Rumen-inert FFAs re pre-hydrolyzed, mostly hydrogented nd purified during mnufcturing. This form of rumen inert ft requires no further chemicl modifiction y the cow prior to digestion. FFAs usully hve lower melting 5. Biohydrogention (%) of unsturted ftty cids in the rumen of cows fed CSFAs t 3% of the rtion dry mtter Ftty cid 0% CSFAs dded 3% CSFAs dded C18: C18: C18: Totl C Effects of omslly infusing into lctting diry cows 450 g of either PUFA or sturted ftty cids (SFA) on DMI, totl ftty cid digestiility percent (TFADIG%) nd DEI No. of DMI, l./dy TFADIG, % DEI, Mcl/dy----- Author cows Control SFA PUFA Control SFA PUFA Control SFA PUFA Drckley et l., * 55.2* 49.4* * 72.1* 63.9* Christensen et l., * 68.7* 62.0* Bremmer et l., 1998 c x 47.5 x 43.9 y x 61.2 x 55.9 y Weighted mens DMI liner contrst P < 0.02; DEI liner contrst DEI orthogonl contrst of SFA versus PUFA c Mens with different superscripts within DMI or DEI differ y 7. Effects of CSFAs on DMI nd milk production of lctting diry cows % CSFAs in DMI Intke DMI, l. per dy NE L, MJ per dy Yield Milk, l. per dy % FCM, l. per dy Milk ft, % Milk protein, % Effects of CSFAs in diets on reproductive prmeters of lctting diry cows First service No. of --conception rte, %-- --Pregnncy rte, %-- Author cows Control CSFAs Control CSFAs Schneider et l., NA NA Skln et l., NA NA Crroll et l., Skln et l., Holter et l., Lucy et l., NA NA Skln et l., Mollem et l., Grci-Bojlil et l., * Weighted mens TABLES 9. Effects of mostly sturted dietry FFAs in diets on reproductive prmeters of lctting diry cows Control 500 g FFAs P-level No. of cows Pregnnt cows Services per conception, pregnnt cows < 0.05 Services per conception, ll cows < 0.05 First service conception rte, % < Overll conception rte, % < Overll pregnncy rte, % < 0.08 Dys open > 0.10 FFA tretment significntly differs from control t indicted P-level. 10. Effects of preprtum FFAs fed to dry cows during lst three weeks of gesttion on reproductive mesures Prmeter No FFAs 200 g/dy FFAs Pregnncy rte, % Dys open Conception rte, % 26 40

3 point thn PHT or CSFAs nd hve the tendency to e less solule in the rumen thn ft supplements high in unsturted ftty cids. FFAs lso hve few or no negtive effects on ruminl fermenttion compred to ft sources high in unsturted ftty cids (Chlup et l., 1984; Chn et l., 1997). They lso hve een shown to hve miniml or no negtive effects on DMI (Chillird, 1993; Dvis, 1993; Allen, 2000). Due to the known nd ccepted negtive effects of PHT on oth digestiility nd milk production (Elliott et l., 1994; 1999; Weiss nd Wytt, 2004), the reminder of this rticle will e devoted to compring the other two rumen inert fts when used in lctting diry cow rtions. Effects on milk production Although mny studies hve een done with feeding rumen inert fts, only few hve directly compred feeding CSFAs nd FFAs. Tle 1 reviews seven trils where these two rumen inert fts were directly compred. As Tle 1 shows, erly trils used few cows to determine differences mong tretments. Despite this, Grummer (1988) nd Hrvtine nd Allen (2002) did oserve significnt (P < 0.01 nd 0.05, respectively) decrese in milk protein response for CSFAs versus FFAs. Weighting mens y numer of cows for ech study indicted trend towrd greter dily milk production, ft-corrected milk (FCM) production, milk ft percent nd milk protein percent when FFAs were compred to CSFAs. Effects on DMI Studies directly testing differences etween FFAs nd CSFAs on DMI, ftty cid digestiility nd odyweight chnges re shown in Tle 2. Dt indicted tht there ws little difference in digestiility of ftty cids delivered y either CSFAs or FFAs. The most pronounced difference etween these two rumen inert fts ws effect on DMI. In the two most recent studies conducted y Hrvtine nd Allen nd reported t the 2002 nd 2003 joint Americn Diry Science Assn. nd Americn Society for Animl Science meetings, significnt (P < 0.01 nd 0.05) DMI depression occurred when CSFAs were compred to FFAs. Dt lso showed tht in five of seven direct study comprisons, FFAs resulted in numericlly greter DMI thn CSFAs. TABLE Mrch 14, 2005 FEEDSTUFFS Effects of FFAs fed to preprtum cows on erly ovultion nd pregnncy rtes during susequent lcttion ---First ovultion prior to 50 dys postprtum--- Tretment Cows oserved pregnnt % cows pregnnt P-level Control 14 of g/dy FFA 23 of 23* 100* < 0.05 In 1993, Chillird reviewed use of rumen inert fts nd sturted fts in lctting cow rtions (Tle 3). Dt from this review re consistent with dt in Tle 2 in tht DMI ws significntly (P < 0.01 or 0.05) depressed y the ddition of CSFAs to lctting cow diets. Sturted fts lso resulted in twice (P < 0.01) 4% FCM production thn CSFAs compred to controls. Milk ft percentge ws unffected while milk protein percentge ws negtively ffected y oth sturted fts (P < 0.05) nd CSFAs (P < 0.05) ut less with sturted fts. Bodyweight chnge ws not significntly ffected y the ddition of sturted fts or CSFAs, ut sturted fts hd numericl increse while CSFAs hd negtive numericl influence on odyweight chnge. This logiclly follows since DMI ws significntly depressed (P < 0.01) with CSFAs in diets. More recently, Allen (2000) extensively reviewed effects of ft supplementtion on DMI (Tle 4). A regression eqution involving 24 studies, where CSFAs were fed nd compred to controls, showed tht for every 1% dded CSFA over the control, 2.5% DMI depression ws found. This finding is reiterted in the Ntionl Reserch Council (NRC) 2001 diry nutrient recommendtions on p. 31. Allen (2000) lso reported tht in 11 out of 24 comprisons, CSFAs significntly depressed DMI. Furthermore, 22 out of the 24 comprisons were numericlly lower in DMI when CSFAs were dded to rtions. Allen reported, Although energy utiliztion is more efficient for digested ft thn digested crohydrte, it is cler tht ddition of ft to the diet does not lwys result in incresed net energy intke nd tht reduction in DMI is one of the primry resons. From these pulished dt (Tle 2) nd the criticl review ppers pulished in the Journl of Diry Science (Chillird, 1993; Allen, 2000), it is evident tht feeding lctting diry cows CSFAs, even t 0.50 l. per dy, cn significntly depress DMI. Allen (2000) lso noted tht no effect of dded ftty cids on DMI ws oserved for hydrogented ft in 21 comprisons. Bsed on these pulished journl rticles nd criticl reviews, DMI depression due to the inclusion of CSFAs in the rtions of lctting cows is prolemtic. It is resonle to ssume tht if nutritionist or diry producer decided to replce 0.5 l. of corn, or 0.45 Mcl of net energy, with 0.5 l. of CSFAs, or Mcl of net energy, the difference should e or Mcl. However, when 2.5% reduction in DMI is fctored in, the net effect is reduction in totl dily net energy intke. Assuming tht cow is consuming 50 l. per dy of dry mtter nd tht the rtion contins 0.78 Mcl net energy for lcttion (NE L ), totl dily NE L intke would e 39 Mcl. If DMI is reduced 2.5%, or 0.98 Mcl, dding ck NE L from CSFAs, or Mcl, still leves deficit of 0.34 Mcl NE L. This is consistent with Chillird s (1993) review tht negtive odyweight chnge occurred when CSFAs were included in the rtion. Finncil consequences cn e clculted with current nd locl dt. Mode of ction ffecting DMI depression from feeding CSFAs to lctting cows hs een delineted in three primry res: pltility, ruminl nd gstrointestinl motility effects. Grummer et l. (1990) studied pltility effects of four different ft products (sodium-lginte encpsulted dry tllow, tllow, FFAs nd CSFAs) on two university nd two commercil frms involving 209 lctting cows. Different ft products were fed lone, top dressed on the grin or included in the grin mix. In ll cses, FFAs were preferred to CSFAs whether using qulittive or quntittive mesurements. In ddition, it ws oserved tht cows improved intke of three ft products, ut not of CSFAs, when seven-dy period ws llowed for dpttion. This oservtion ws significnt ecuse it indicted possile inhiitory mechnism eyond pltility or generl dpttion tht led to continued nd prolonged DMI depression.

4 4 FEEDSTUFFS, Mrch 14, 2005 A second possile mode of ction regrding DMI depression from use of CSFAs is disruption of ruminl fermenttion due to unsturted ftty cid effects. Although CSFAs were oserved to e inert in the rumen in n in vitro tril (Sukhij nd Plmquist, 1990), Wu et l. (1991) oserved tht unsturted 18 cron ftty cids in CSFAs were 58% iohydrogented in vivo (Tle 5). The uthors noted tht iohydrogention could only occur fter dissocition of the clcium slt. Hwke nd Silcock (1969) hd similr findings nd concluded tht free croxyl group of the ftty cid ws required for iohydrogention to proceed. Consequently, CSFAs re not inert in the rumen. Therefore, negtive effects of unsturted ftty cids on rumen fermenttion re prole. Wu et l. (1991) lso concluded tht the percent of iohydrogention incresed s the level of unsturtion incresed, s noted in Tle 5. Negtive effects of unsturted ftty cids on fier digestion nd milk ft content re well recognized (NRC, 2001). However, since studies show only smll differences in fier digestion nd milk ft content when CSFAs re fed to lctting cows, this mode of ction is proly not the mjor fctor in DMI depression. Interestingly, significnt iohydrogention of C18:1, C18:2, nd C18:3 ftty cids results in higher levels of steric cid reching the duodenum regrdless if the dietry source is CSFAs or oilseeds or forges. Ruminl ction lrgely converts these ftty cids to C18:0. This picture is further confused when pplying non-ruminnt ft digestion spects to ruminnts, prticulrly when downgrding digestiility of steric versus plmitic or C18 unsturted ftty cids. Most recently, Bumn et l. (2003) noted tht digestiility does not differ significntly etween C16 nd C18 sturted ftty cids nd is lower for longer-chin sturted ftty cids compred to polyunsturted ftty cids (PUFA). They further noted tht differences in digestiility mong individul ftty cids contriute very little to the extensive vrition (out 60-90%) in the digestiility of dietry lipids. Rther, the mjority of this vrition reflects differences mong individul experiments nd, thus, reltes to differences in diets nd specific feed components (Demeyer nd Doreu, 1999). The third possile mode of ction regrding DMI depression in cows fed CSFAs is the effect on gstrointestinl motility. Drckley et l. (1992), Christensen et l. (1994) nd Bremmer et l. (1998) conducted numer of experiments where they omslly infused into lctting diry cows 450 g per dy of oils contining high levels of sturted ftty cids or unsturted ftty cids (Tle 6). These dt show n verge DMI depression of 8% from omslly infusing PUFA into lctting diry cows. Reviews of Chillird (1993) nd Allen (2000) estimted reduction of only % t this level of DMI. However, uthors lso concluded tht DMI depression nd the susequent drop in digestile energy intke (DEI) ws greter thn the energy vlue of infused PUFA. These three studies illustrted the most likely primry mode of ction ffecting DMI depression when feeding CSFAs. As the level of PUFA flow increses into the smll intestine, there ppers to e mechnism tht triggers the stiety center to reduce DMI. Woltmn et l. (1995) found tht duodenl infusion of oleic cid in rts reduced feed intke nd tht portion of the effect ws medited through gut hormone, cholecystokinin (CCK). Choi nd Plmquist (1996) oserved tht feeding incresing levels of CSFAs to lctting diry cows decresed DMI linerly nd incresed concentrtions of CCK. Tle 7 illustrtes dt dpted from tht study. The uthors concluded tht feeding incresing mounts of dietry ft (CSFAs) linerly decresed feed nd energy intkes nd linerly incresed plsm CCK nd pncretic polypeptide concentrtions in lctting cows. They suggested tht decresed feed intke in cows fed CSFAs ws medited y incresed plsm CCK nd pncretic polypeptide concentrtions. Interestingly, even though DMI nd net energy intke decresed, milk nd 4% FCM production incresed. The only logicl reson for the increse in production would hve een from moiliztion of ody ft stores. This study clerly indicted physiologicl mechnism ssocited with DMI reduction due to CSFA ddition to lctting diry cow diet nd is in greement with Allen s (2000) review. Drckley et l. (1992) lso hd suggested tht degree of unsturtion of ftty cids reching the smll intestine of diry cows could ffect gstrointestinl motility nd reduce DMI. Given tht DMI depression experienced when CSFAs re fed is now well documented, the dilemm ecomes how to meet erly-lcttion, high-producing diry cows energy requirements for milk production, reproduction nd odyweight gin. A recent review (Grummer nd Rstni, 2003) summrized time required fter clving for lctting cows to rech positive energy lnce nd concluded tht totl energy intke ws the key fctor. They found energy intke ws more highly correlted thn FCM production with time postclving for cows to rech positive energy lnce. Energy intke is the product of energy density in the diet nd DMI. If n increse in energy density is ccompnied y reduction in DMI, the level of energy intke is limited, which, in turn, limits the return to positive energy lnce nd/or reduces production response. Effects on reproduction Influence of rumen inert ft supplements on reproduction is not well understood nd is hot topic mong nutritionists, reproductive physiologists nd veterinrins. Reserch feeding FFAs (Ferguson et l., 1990) nd CSFAs (Skln et l., 1991) showed significnt positive effects of rumen inert ft ddition to lctting cow rtions on services per conception, pregnncy rtes nd dys open. However, Skln et l. (1994), Mollem et l. (1997), Grci-Bojlil et l. (1998) nd Mollem et l. (1999) hve ll oserved comintion of negtive results, positive results nd some contrdictory results. A review of nine studies with 701 cows (Tle 8) found very few significnt differences due to high vriility in dt. Thus, reproductive prmeters require more oservtions to mke meningful sttisticl comprisons. These dt indicted few significnt differences (P < 0.05) etween tretments for either first service conception rte or pregnncy rte. Slight improvement in first service conception rte ppered from CSFA tretments, ut lrger numericl reduction ws noted in overll pregnncy rte when CSFAs were dded to rtions of high-producing, erly-lcttion cows in these studies. There re fewer pulished studies compring dded FFAs to control diets with reproductive mesurements. Ferguson et l. (1990) compred FFAs dded t 500 g per dy to control diets fed in three Pennsylvni herds nd one Isreli herd (Tle 9). The uthors generlly concluded tht

5 FFA ddition to rtions fed in these herds enefited reproduction y minimizing odyweight loss nd hstening odyweight gin postprtum. Both of these effects hve een shown to enefit conception rte. Most recently, Frjlt nd Butler (2003) reported reproductive responses when 81 dry cows were fed either 200 g FFAs or no FFAs during the lst 21 dys of the dry period (i.e., close-up cows). Cows were first red postprtum eginning t dy 55 nd were red y signs of stnding het until dy 220 postprtum (Tle 10). The uthors oserved tht close-up cows receiving 200 g per dy of FFAs in their diets hd higher (P < 0.05) pregnncy rtes nd conception rtes nd fewer (P < 0.05) dys open. Additionlly, cows exhiiting their first ovultion efore 50 dys postprtum were oserved to e nerly twice s likely to ecome pregnnt prior to 220 dys postprtum thn cows hving their first ovultion fter 50 dys postprtum. The uthors lso oserved tht cows fed 200 g FFAs in the close-up period nd tht hd n ovultion prior to 50 dys postprtum were even more likely to e pregnnt t 220 dys postprtum. Furthermore, cows losing less ody condition score in erly lcttion were oserved to hve more ovultions prior to 50 dys in milk (Tle 11). These results re the first to show enefit when ft ws fed to dry cows. A possile mechnism for this response my e derived from the work of Mollem et l. (1999). They oserved tht oleic nd linoleic cids were found in lower concentrtions in the non-esterified ftty cids (NEFA) frction of folliculr fluid in estrdiol-ctive versus estrdiol-inctive or estrdiol-less ctive follicles s determined y folliculr size. A significnt negtive correltion coefficient etween these unsturted ftty cids nd the estrdiol concentrtion in folliculr fluid suggested tht preovultory growth ws ccompnied y decrese in these two ftty cids nd n increse in the proportion of plmitic cid. Steric cid ws numericlly elevted y nerly 14% t the sme time in NEFA frction of folliculr fluid of estrdiolctive follicles over the inctive or less ctive follicles. Steric cid in the phospholipid frction of folliculr fluid of estrdiol-ctive follicles ws significntly higher (P < 0.05) thn the less ctive or inctive follicles (26.4 versus 23.6% of phospholipids). FFAs fed in this study contined 47% steric cid, 37% plmitic cid nd only 15% oleic cid. This reserch my explin why CSFAs, which re higher in oleic nd linoleic cid compred to FFAs, hve more vrile results in reproductive trils. Another potentil fctor is Grummer nd Rstni s (2003) finding in their study tht net energy intke is more highly correlted (r = 0.58, P < ) with time required to rech energy lnce, nd thus, cows my e in negtive energy lnce longer nd lose more ody condition when fed CSFAs ecuse of DMI depression. Frjlt nd Butler (2003) concluded Mrch 14, 2004 FEEDSTUFFS 5 tht cows losing less ody condition hd more ovultions prior to 50 dys in milk, nd those cows with n ovultion efore 50 dys in milk were 2.4 times more likely to ecome pregnnt efore 220 dys in milk. Conclusions Dry ft products re generlly thought to e rumen inert nd to hve eneficil physicl properties, prticulrly for onfrm use. PHT is limited primrily y its higher melting point, which reduces its digestiility nd susequent energy vlue to the diry cow. FFAs nd CSFAs now hve considerle ody of literture for comprison of effects when fed to lctting diry cows. This pper reviewed direct comprison studies of these two dry ft sources nd found primry differences due to greter DMI nd pltility of FFAs. This in turn hs corresponding positive effects on energy lnce, odyweight chnge nd reproductive performnce with similr digestiility. The mode of ction for reduced DMI when using CSFAs ppers to e primrily due to negtive effects of gstrointestinl motility, rumen function nd pltility, in tht order. Reduced DMI ffects the mount nd durtion of negtive energy lnce in erly lcttion, susequent milk production nd reproduction nd economic vlue. REFERENCES The extensive list of references my e found t or y contcting Tim Lundeen t tlundeen@feedstuffs.com.