(Key Words: Horse, Glucose, Insulin, Dietary fat, Dietary fiber)

Transcription

1 C.A. Willims Journl Article 1 26 Plsm Glucose nd Insulin Responses of Thoroughred Mres Fed Mel High in Strch nd Sugr or Ft nd Fier ABSTRACT: Plsm concentrtions of glucose nd insulin following mel were compred in twelve Thoroughred mres fed pelleted concentrte (PC), trditionl sweet feed high in sugr nd strch (SS), or feed high in ft nd fier (FF). The feeds hd similr DE nd CP, ut differed in ft (19, 32, nd 166 g/kg DM, respectively) nd NDF (199, 185, nd 369 g/kg DM, respectively). Mres were pired y foling dte nd weight then rndomly ssigned into two groups. All mres received PC in lte gesttion; then, fter foling, one group ws fed SS, the other FF for trils in erly nd lte lcttion. For ech experiment, mres were plced in stlls nd deprived of feed overnight. A series of lood smples ws collected vi jugulr ctheter from 0 to 390 min fter consumption of 1.82 kg of feed. Plsm ws nlyzed for glucose nd insulin. Bseline vlues, pek vlues nd res under curves (AUC) were compred y ANOVA. Bseline vlues were 74.7 ± 10.9 mg/dl for glucose nd 5.86 ± 1.80 miu/l for insulin for ll diets nd stges. Responses to PC did not differ etween the two groups, indicting the groups were metoliclly similr so there is no need for co-vrite. Pek plsm glucose (P < 0.001) nd insulin (P < 0.001) concentrtions were higher in SS group thn in FF during oth erly nd lte lcttion. Glucose (P < 0.002) nd insulin (P < 0.003) AUCs were higher in SS thn in FF during oth erly nd lte lcttion. These results indicte tht metolic fluctutions re moderted y the replcement of sugr nd strch with ft nd fier. This replcement my reduce the risk of certin digestive nd metolic disorders tht hve een linked to feeding mels of grin-sed concentrtes. (Key Words: Horse, Glucose, Insulin, Dietry ft, Dietry fier)

2 C.A. Willims Journl Article 1 27 Introduction Concentrtes re commonly fed s two mels dy to supplement forge (psture nd/or hy) in the diet of horses, especilly those with energy nd nutrient requirements ove mintennce. A mel contining high percentge of grin-sed concentrte hs een ssocited with digestive, circultory, metolic nd hormonl chnges (Clrke et l., 1990). Arupt increses or high intkes of solule crohydrtes my crete lrge fluctutions in the growth curve (Hoffmn, 1997) nd increse the risk of certin digestive nd metolic disorders (Kronfeld, 1998). Replcement of strch with ft in the feed hs een used to prevent rhdomyolysis (Kronfeld, 1973; Vlentine et l., 1998; McLey et l., 1999), to enhnce eroic (Slde et l., 1975) nd neroic exercise (Oldhm et l., 1990), nd to reduce excitility (Hollnd et l., 1996). Our lortory hs een developing horse feeds in which sugr nd strch re replced with ft nd fier (Kronfeld, 1996; Hoffmn nd Kronfeld, 1999). The present study compres the glycemic nd insulinemic responses of typicl concentrtes nd supplement formulted with sufficient ft to chieve the sme energy density of typicl concentrte nd sufficient fier to llow its use s complete feed. Mterils nd Methods Thirty-six mel feeding experiments were conducted, 3 on ech of 12 Thoroughred mres, ged 5 to 18 yr. The protocol ws pproved y the institutionl niml cre nd use committee nd performed t the Virgini Tech Middleurg Agriculture Reserch nd Extension Center. The mres were mintined on djcent luegrss/white clover pstures with free ccess to lflf/orchrd grss hy. They were pired y weight nd foling dte, then rndomly ssigned to two groups s of Jnury. For three months prior to foling the pregnnt mres were fed pelleted concentrte (PC, PurePride-200, Purin Mills, St Louis, MO). The mres were introduced to the experimentl feeds fter foling; one group received control diet (SS) which ws formulted to closely resemle textured sweet

3 C.A. Willims Journl Article 1 28 feed high in sugr nd strch, the other group received test feed high in ft nd fier (FF). The feeds were formulted (Tle 1) to e isocloric nd isonitrogenous, nd their minerl nd vitmin contents were lnced with the pstures to meet or exceed recommendtions (NRC, 1989). Ech horse received two mels dily, totl of 3.5 to 4.0 kg, which ws one-hlf to one-third of recommended energy requirements (NRC, 1989). Smples of the three supplements were sumitted to Diry One (DHI Forge Testing Lortory, Ithc, NY) for proximte nd minerl nlysis (Tle 2). The FF feed ws higher in ft (P < 0.001) nd NDF (P < 0.001), ut lower in NSC (P = 0.010) thn SS nd PC. Trils were conducted in April (3-6 weeks efore foling), June (3-6 weeks fter foling), nd August (10-14 weeks fter foling). Ech mre ws weighed on n electronic scle (Tyrel pltform, TC-105, Alweights Hmilton Scle Corp, Richmond, VA) then plced in stll overnight (12 to 18 h) with free ccess to wter ut no feed. A series of lood smples (30 ml drwn into Vcutiner tues contining sodium heprin, Becton Dickinson nd Compny, Frnklin Lkes, NJ) ws collected vi jugulr ctheter t 0, 30, 60, 90, 150, 210, 270, 330, nd 390 min fter mel of 1.82 kg of respective feed. The first smple ws otined immeditely efore the feed ws given. The SS mels were consumed in 20 to 30 min, the FF in 30 to 40 min. Blood smples were immeditely centrifuged t 1600 g for 10 min nd plsm ws removed nd stored t -20 o C until nlysis. Plsm glucose concentrtions were determined y glucose oxidse method using chemicl utonlyser (Kit # , Beckmn Synchron CX5CE, Bre, CA). Plsm insulin ws determined y rdioimmunossy (Cot-A-Count Insulin, kit # TKINX, Dignostic Products Corportion, Ls Angeles, CA). Ares under the concentrtion-time curve (AUC) were clculted s summed trpezoids. The effects of horse, diet nd stge of the reproductive cycle were evluted y ANOVA (SAS, 1996). In the generl liner models procedures, the degrees of freedom were insufficient to run full model with ll interctions. Without interctions, the min effects of horse hd P vlues of 0.28 to 0.72, nd the min effects of stge hd P vlues of 0.20 to Becuse feed, stge nd their interction were of primry interest, mixed model ws used with horse s rndom effect. Mens were compred y the Tukey test with P < 0.05.

4 C.A. Willims Journl Article 1 29 Results The horses weighed 669 ± 193 kg in April, 583 ± 168 kg in June, nd 575 ± 173 kg in August. All the horses remined in good helth throughout the oservtionl period. No differences were found etween the feeds (PC, SS or FF) nd stges (lte gesttion, nd erly nd lte lcttion) in seline dt for plsm glucose (P = 0.36) nd insulin (P = 0.15); men concentrtions were 74.7 ± 10.9 mg/dl nd 5.86 ± 1.80 miu/l, respectively. The glucose nd insulin curves for the comined PC dt of twelve horses re illustrted in Figure 1. The glucose nd insulin AUC were the sme etween experimentl groups of horses receiving PC (P = 0.482, nd P = 0.339, respectively), which eliminted the need for using these dt s co-vrites in lter experiments. Peks of plsm glucose nd insulin were the highest vlues, usully oserved in the 90-min smples, lthough men vlues were not significntly different from 60 to 150 min. The effects of feed nd stge on pek glucose nd glucose AUC for mres fed the different diets re shown in Figure 2 nd 2, respectively. Glucose response for PC nd SS were similr, except tht pek glucose ws numericlly lower following the SS mel during lte lcttion thn fter the PC mel. Glucose pek nd AUC were lower following FF thn fter SS or PC (P < 0.001, nd P < 0.002, respectively) t ll stges. The effects of feed nd stge on pek insulin nd AUC re shown in Figure 3 nd 3, respectively. Insulin response for PC nd SS were similr. Insulin pek nd AUC were lower in FF thn SS or PC (P < 0.001, nd P < 0.003, respectively) t ll stges. Comprison of responses to feeds during erly nd lte lcttion reveled the sme pttern of glucose nd insulin responses through ll the sets of dt (Figures 2 nd 2, 3 nd 3). There were consistent decreses in glucose pek nd AUC for the SS group, compred to increses tht were less mrked in the FF group. The corresponding P vlues for the feed*stge interction were 0.20 nd 0.17 for glucose pek nd AUC, respectively. The slight chnges in opposite directions were evident for insulin pek nd AUC, ut the interctions hd P vlues of 0.26 nd 0.38, respectively.

5 C.A. Willims Journl Article 1 30 Discussion Procedurlly, these experiments resemle glucose tolernce tests, which give informtion out the glucose sttus of the niml, nd glycemic indices, which give informtion out the glucose-equivlents in the diet (Roerts nd Hill, 1973; Jenkins et l., 1981). The present glycemic nd insulinemic responses re intended to give informtion on isocloric mels with differing contents of glucose-equivlents, following previous studies in horses (Stull nd Rodiek, 1988; Rlston, 1992; Pgn et l., 1999). In the present experiments, replcement of strch nd sugr with ft nd fier moderted the postprndil glycemic nd insulinemic effects of mel fed to pregnnt nd lctting mres. Chnges in plsm glucose nd insulin re two of the primry fetures of the glucose-ftty cid cycle, which is ssocited with mel feeding (Rndle, 1998). Not mesured here were other vriles in the feeding-fsting cycle, such s free ftty cids, triglycerides, cortisol, thyroid hormones, growth hormone nd insulin-like growth fctors (Kronfeld, 1998). Dily chnges in insulin nd counter-regultory hormones my contriute to the development of certin metolic disorders (Glde nd Reimers, 1985; Clrke et l., 1990; Rlston, 1996). Our results suggest tht the metolic nd helth impcts re likely to e similr for our experimentl SS nd commercil feeds, such s PC, ut moderted for mels of FF. Interprettion of these experiments is complicted in two regrds. One involves the possile interction of the feed nd reproductive stge. The other concerns the reltive importnce of decresing glucose-equivlents nd incresing ft or fier on the results. A single pttern of lower glucose nd insulin responses etween SS nd FF ws seen in ll trils. The slight decreses from erly to lte lcttion in the pek glucose nd insulin, nd the AUCs of glucose nd insulin in the SS groups were ccompnied y slight increses in these vriles in the FF group. Erly lcttion experiments in the present study encompss the first two months fter foling when the milk yield of mre is t its pek, pproximtely 11.8 kg/d or 2.3 % of ody weight (Gis et l., 1982). In contrst, tests in lte lcttion were performed within the fifth or sixth month period fter foling

6 C.A. Willims Journl Article 1 31 when the milk yield hs decresed to 9.8 kg/d or 1.9 % ody weight. The possiility of feed nd stge trend is likely to represent n overll decrese in glucose removl from lood lter in lcttion, when the rte of glucose removl from lood specificlly for milk lctose synthesis nd volume production is decresed (Evns, 1971). This repeted nd consistent tendency for n interction etween feed nd stge invites further investigtion, especilly ecuse chnges of plsm concentrtions of glucose nd insulin, s well s chnges in trcer glucose kinetics, hve een ssocited previously with chnges in reproductive stge (Evns, 1971; Fowden et l., 1984). Either lowering the glucose-equivlents in the feed or incresing the ft or fier contents could contriute to chnges in the glycemic responses to mel. Higher ft in the diet my dely or decrese the pek glycemic response y retrding gstric emptying in humn sujects (Wolever, 1990). However, this dely should not ffect the AUC. The effect of high ft mel on gstric emptying hs not een studied in horses to our knowledge. The glucose-equivlents would e pproximted y NSC (Tle 2), which mounts to 1,045, 1,035 nd 339 g in the mels of PC, SS nd FF, respectively. This 3- fold difference in NSC intke my e compred to the 2.5-fold difference etween the SS nd FF feeds in glucose AUC erly lcttion nd the 1.6-fold difference during lte lcttion. The increse in plsm insulin concentrtion reflects n incresed rte of insulin relese into the lood in response to glucose sorption nd hyperglycemi (Myes, 1996). The susequent decline proly represents modertion in the rte of insulin relese nd n increse rte of insulin removl from lood. The differences in insulin AUC etween SS nd FF groups were much greter (12-fold nd 6-fold in erly nd lte lcttion, respectively) thn corresponding differences in glucose AUC (154 % nd 62 %, respectively). This finding suggests tht the mount of glucose sorption, thus the chnge in glucose concentrtion in the plsm, hd greter impct thn certin level of plsm glucose concentrtion per se on the mgnitude of the insulin response. Severl studies hve compred the effects of corn grin mel to those of corn fortified with 10 % corn oil. In horses fed mel of lflf hy or corn fortified with 10 % corn oil they produced plsm glucose peks of 103 or 116 mg/dl, respectively (Stull nd

7 C.A. Willims Journl Article 1 32 Rodiek, 1988). For mels of corn only or corn nd lflf (50:50) the glycemic response reched level of out 142 mg/dl for oth mels. Another study used six mels fed to horses t mintennce nd found smller differences in pek glucose concentrtions, which rnged from 99 mg/dl for lflf hy to 108 mg/dl for sweet feed (Pgn et l., 1999). These studies hve found vrious glucose responses rnging from slight vrition etween different diets, to lrge rnge of concentrtion peks. Compred to previous studies, the mgnitude of responses in our experiments ws similr for glucose (Stull nd Rodiek, 1988; Pgn et l., 1999), ut tended to e lower for insulin, especilly following mel of FF (Figure 3). Insulin AUCs were out 1,700 min miu/l following n lflf mel, compred to 5,000 to 9,200 min miu/l for grin mixes (Stull nd Rodiek, 1988). The higher fier content in the FF most likely cused higher production of cette, propionte nd utyrte in the gut. These cn control plsm glucose concentrtion y cting s precursor (propionte) or y spring glucose oxidtion (minly cette nd ethydroxyutyrte). Such effects re likely to e smller thn tht of direct glucose sorption, nd therey explin the results of severl studies tht evluted the effects of feeding hy nd other roughges. Pek insulin concentrtions were 29 nd 49 miu/l following mels of corn (7-fold increse from seline), nd corn nd lflf (12- fold increse), respectively (Stull nd Rodiek, 1988). In contrst, plsm insulin incresed only 1.6 times following n lflf mel. In our study, pek insulin concentrtions were 8.7 times seline for PC nd SS compred to 1.7 times following FF mel. Thus, the FF feed, which hs similr energy density of typicl concentrte, hs the insulinogenic effect of roughge, lflf hy. In prcticl humn dietetics, the glycemic index (GI) is used to design mels for the feeding of thletes efore nd fter n event (Burke et l., 1998) s well s diets for the mngement of non-insulin dependnt dietes mellitus (Brnd-Miller nd Foster-Powell, 1999). On this sis, foods re clssified s low-gi or high-gi. Low-GI mels my e used to reduce the risk of dietes, long with coronry hert disese nd oesity. Consuming high-gi mel my exggerte the insulin nd glucose responses, which could excerte certin metolic prolems. In regrd to exercise, high-gi mels consumed

8 C.A. Willims Journl Article 1 33 fter exercise my increse glycogen storge. In contrst, low-gi mels consumed efore endurnce exercise my prolong glucose vilility nd enhnce performnce (Burke et l., 1998). Similrly, in equine nutrition, the circultory, digestive, metolic nd hormonl responses to mel (Clrke et l., 1990; Kronfeld, 1998), including the glycemic nd insulinemic responses, my e pplied to feeding mngement during nd fter n thletic event (Stull nd Rodiek, 1995) nd reducing the risks of gstric ulcers (Murry, 1999), colic (Cohen et l., 1999), lminitis, osteochondrosis (Rlston et l., 1996) nd certin types of rhdomyolysis (Kronfeld, 1973; Vlentine et l., 1998; McLey et l., 1999). Implictions Horse feeds contining undnt strch from grin nd sugr from molsses, such s typicl pelleted or textured concentrtes, hve profound metolic nd hormonl effects tht my e reduced or eliminted y the replcement of glucose-equivlents with ft nd fier. This exchnge of nutrients my e useful in the feeding mngement of horses performing intense work, nd in reducing the risks of certin digestive nd metolic disorders. However, the difference etween the use of these energy sources in mres during different reproductive stges needs to e explored in more detil.

9 C.A. Willims Journl Article 1 34 Literture Cited Brnd-Miller, J., nd K. Foster-Powell Diets with low glycemic index: from theory to prctice. Nutr. Tody. 34: Burke, L.M., G.R. Collier, nd M. Hrgreves Glycemic index - new tool in sport nutrition? Int. J. Sport Nutr. 8: Clrke, L.L., M.C. Roerts, nd R.A. Argenzio Feeding nd digestive prolems in horses. Vet. Clin. N. Am: Equine Prct. 6: Cohen, N.D., P.G. Gis, nd A.M. Woods Dietry nd other mngement fctors ssocited with colic in horses. J. Am. Vet. Med. Assoc. 215: Evns, J.W Effect of fsting, gesttion, lcttion nd exercise on glucose turnover in horses. J. Anim. Sci. 33: Gis, P.G., G.D. Potter, R.W. Blke, nd W.C. McMulln Milk production of qurter horse mres during 150 dys of lcttion. J. Anim. Sci. 54: Glde, M.J., nd T.J. Reimers Effects of dietry energy supply on serum thyroxine, triiodothyroine nd insulin concentrtions in young horses. J. Endocrinol. 104: Fowden, A.L., R.S. Comline, nd M. Silver Insulin secretion nd crohydrte metolism during pregnncy in the mre. Equine Vet. J. 16: Hoffmn, R.M. nd D.S. Kronfeld Nutrient requirements for grzing horses: development of n optiml psture supplement. In: Grnsworthy, P.C. nd J. Wisemn (Eds). Recent Advnces in Animl Nutrition. Nottinghm University Press, Nottinghm, U.K. Hoffmn, R.M Crohydrte nd ft supplementtion in grzing mres nd fols. Ph.D. disserttion. Virgini Polytechnic Institute nd Stte University, Blcksurg, VA. Hollnd, J.L., D.S. Kronfeld, nd T.N. Mechm Behvior of horses is ffected y soy lecithin nd corn oil in the diet. J. Anim. Sci. 74: Jenkins, D.J.A., T.M.S. Wolever, R.H. Tylor, H. Brker, H. Fielden, J.M. Bldwin, A.C. Bowling, H.C. Newmn, A.L. Jenkins, nd D.V. Goff Glycemic index of foods: physiologicl sis for crohydrte exchnge. Am. J. Clin. Nutr. 34:

10 C.A. Willims Journl Article 1 35 Kronfeld, D.S Clinicl Assessment of Nutritionl Sttus of the Horse. In: T. Wtson (Ed.) Metolic nd Endocrine Prolems of the Horse. pp W.B. Sunders Compny, London. Kronfeld, D.S Dietry ft ffects het production nd other vriles of equine performnce, under hot nd humid conditions. Equine Vet. J. Suppl. 22: Kronfeld, D.S Diet ffects performnce of rcing sled dogs. J. Am. Vet. Med. Assoc. 162: McLey, J.M., S.A. Sorum, S.J. Vlerg, W.E. Mrsh, nd M.D. Sorum Epidemiologic nlysis of fctors influencing exertionl rhdomyolysis in Thoroughreds. Am. J. Vet. Res. 60: Myes, P.A Gluconeogenesis nd Control of the Blood Glucose. In: J. Doln nd C. Lngn (Ed.) Hrper s Biochemistry. pp Appleton nd Lnge, Stmford, Conn. Murry, M.J Gstroduodenl ulcertion in fols. Equine Vet. Edu. 11: NRC Nutrient Requirements of Horses (5 th Ed. ). Ntionl Acdemy Press, Wshington, D.C. Oldhm, S., G.D. Potter, J.W. Evns, S.B. Smith, T.S. Tylor, nd W.S. Brnes Storge nd moiliztion of muscle glycogen in exercising horses fed ft supplemented diet. J. Equine Vet. Sci. 10: Pgn, J.D., P.A. Hrris, M.A.P. Kennedy, N. Dvidson, nd K.E. Hoekstr Feed type nd intke ffect glycemic response in Thoroughred horses. Proc. Equine Nutr. Physiol. Soc. 16: Rlston, S.L Hyperglycemi/hyperinsulinemi fter feeding mel of grin to young horses with osteochondritis dissecns (OCD) lesions. Pferdeheilkunde. 12: Rlson, S.L Effect of solule crohydrte content of pelleted diets on postprndil glucose nd insulin profiles in horses. Pferdeheilkunde. 8: Rndle, P.J Regultory interctions etween lipids nd crohydrtes: the glucose ftty cid cycle fter 35 yers. Dietes Met. Re. 14: Roerts, M.C. nd F.W.G. Hill The orl glucose tolernce test in the horse. Equine Vet. J. 5: SAS SAS/STAT User s Guide. (Relese 6.12). SAS Inst. Inc., Cry, NC.

11 C.A. Willims Journl Article 1 36 Slde, L.M., L.D. Lewis, C.R. Quinn, nd M.L. Chndler Nutritionl dpttion of horses for endurnce performnce. Proc. Equine Nutr. Soc. 4: Stull, C.L., nd A.V. Rodiek Stress nd glycemic responses to postprndil intervl nd feed components in exercising horses. J. Equine Vet. Sci. 15: Stull, C.L., nd A.V. Rodiek Responses of lood glucose, insulin nd cortisol concentrtions to common equine diets. J. Nutr. 118: Vlentine, B.A., H.F. Hintz, K.M. Freels, A.J. Reynolds, nd K.N. Thompson Dietry control of exertionl rhdomyolysis in horses. J. Am. Vet. Med. Ass. 212: Wolever, T.M.S The glycemic index. World Rev. Nutr. Diet. 62:

12 C.A. Willims Journl Article 1 37 Tle 1. Ingredient composition (%) of the sugr nd strch (SS) nd ft nd fier (FF) feeds Ingredient SS FF Dent yellow grin corn Soyen mel 48 % Ot strw 7 7 Alflf Soyen hulls 4 4 Beet pulp 0 10 Cerel grin y-product 0 45 Molsses (cne) 10 5 Diclcium phosphte Limestone 1 1 Minerl premix Vitmin premix The minerl premix provided the following per kilogrm of supplement: ; NCl, 3,774 g; Zn, 422 g; Fe, 208 g; Cu, 89.5 g; Mn, 50.3 g; Se, g; nd Kl,.415 g. The vitmin premix provided the following per kilogrm of supplement: vitmin A, 1,380,080 IU; vitmin D 3, 258,000 IU; vitmin E, 26,455 IU; rioflvin, 701mg; nicin, 3009 mg; folic cid, 66 mg; thimin, 1400 mg; iotin, 42 mg; nd β-crotene, 3527 mg.

13 C.A. Willims Journl Article 1 38 Tle 2. Nutrient composition of the sugr nd strch (SS), ft nd fier (FF) nd the pelleted concentrte (PC) feed s nlyzed in the DHI Forge Testing Lortory (Ithc, NY). Dt re summrized on DM sis s mens ± SE Nutrient SS (n = 12) FF (n = 12) PC (n = 3) DM, % 90.2 ± ± ± 0.42 DE Mcl/kg c 3.34 ± ± ± 0.09 CP, % 13.7 ± ± ± 0.98 ADF, % 10.7 ± ± ± 0.3 NDF, % 18.5 ± ± ± 2.1 Ft, % 3.2 ± ± ± 0.2 NSC, % 64.5 ± ± ± 4.32 Ash, % 6.70 ± ± ± 0.1 C, % 1.15 ± ± ± 0.05 P, % 0.60 ± ± ± 0.02 Mg, % 0.19 ± ± ± 0.02 K, % 1.07 ± ± ± 0.19 N, % 0.25 ± ± ±.0003 S, % 0.22 ± ± ±.0001 Ash = * K * P ± 0.867; dj r 2 = 0.992, P = Nonstructurl crohydrte; NSC = 100 (wter + CP + Ft + Ash + NDF) c DE = 3.6 * NSC * NDF + 8 * Ft * CP / (NSC + NDF + Ft + CP)

14 C.A. Willims Journl Article Glucose Insulin Plsm glucose, mg/dl Plsm insulin, miu/l Mel Time, min 0 Figure 1. Men concentrtion of the plsm glucose (rs) nd insulin (solid line) for twelve mres fed the pelleted concentrte (PC) during lte gesttion. The two groups of mres were comined to illustrte of the glucose nd insulin curves

15 C.A. Willims Journl Article Plsm glucose, mg/dl c c Bseline = PC SS1 SS2 FF1 FF2 Diets Glucose AUC, min mg/dl 12,000 10,000 8,000 6,000 4,000 2,000 0 PC SS1 SS2 FF1 FF2 Diets Figure 2. Pek plsm glucose (A) nd glucose re under the curve (B) in mres fed the pelleted concentrte (PC), feed high in sugr nd strch (SS) nd feed high in ft nd fier (FF) during erly lcttion (1) nd lte lcttion (2). Groups without common superscript differ y P < 0.05

16 C.A. Willims Journl Article Plsm insulin, miu/l Bseline = PC SS1 SS2 FF1 FF2 Diets Insulin AUC, min miu/l 6,000 5,000 4,000 3,000 2,000 1,000 0 PC SS1 SS2 FF1 FF2 Diets Figure 3. Pek plsm insulin (A) nd re under the curve (B) for insulin in mres fed the pelleted concentrte (PC), feed high in sugr nd strch (SS) nd feed high in ft nd fier (FF) during erly lcttion (1) nd lte lcttion (2). Groups without common superscript differ y P < 0.05