*Department of Animal Nutrition and Department of Animal Husbandry, Agricultural University, Wageningen, The Netherlands

Transcription

1 Performnce nd Body Composition of Finishing Gilts (45 to 85 Kilogrms) s Affected by Energy Intke nd Nutrition in Erlier Life: I. Growth of the Body nd Body Components 1 P. Bikker*,2, M.W.A. Verstegen*, B. Kemp, nd M. W. Bosch* *Deprtment of Animl Nutrition nd Deprtment of Animl Husbndry, Agriculturl University, Wgeningen, The Netherlnds ABSTRACT: Forty-eight commercil hybrid gilts were used to determine the effects of energy intke from 20 to 45 kg on the reltionship between energy intke nd weight gin of the body nd body components from 45 to 85 kg. Two groups of 24 gilts received single diet either t 2.2 (restricted) or 3.7 (control) times mintennce ( M ) from 20 to 45 kg. From 45 to 85 kg the pigs were fed the sme diet t one of six intke levels (1.7, 2.2, 2.7, 3.2, or 3.7 M, or d libitum). At 85 kg, the gilts were dissected into orgns, len tissue (trimmed mjor joints), nd other crcss prts (ft frction). In the restricted gilts, body nd len tissue gin between 45 nd 85 kg incresed curvilinerly with incresing energy intke from 432 to 1,412 g/d nd from 228 to 507 g/d, respectively. In the control gilts, body nd len tissue gin incresed from 394 to 1,201 g/d nd from 238 to 508 g/d, respectively. The percentge of len tissue in the crcss decresed curvilinerly with incresing energy intke from 62.9 to 56.5%, nd from 62.5 to 53.9% in the restricted nd control gilts, respectively. The restricted gilts gined on verge 140 g/d fster ( P <.001) nd their crcss len tissue content t slughter ws pproximtely 3% higher ( P <.001). These differences incresed with incresing energy level between 45 nd 85 kg. The incresed gin ws lrgely the result of n increse in orgn growth nd gut contents nd ws only evident up to 65 kg. The higher len content t 85 kg in previously restricted gilts ws not the result of compenstion in len gin but ws lredy present t the end of the restriction phse t 45 kg. Key Words: Pigs, Energy Intke, Weight Gin, Body Composition, Compenstory Growth J. Anim. Sci : Introduction Compenstory gin in pigs fter period of feed restriction hs been studied by mny uthors during severl decdes. Nielsen (1964), Owen (1971), nd Donker et l. (1986) reported n increse in feed intke, nd consequently in body gin, in pigs with free ccess to feed fter period of restriction. Others reported n increse in the efficiency of gin in restrictedly fed nimls fter period t low feeding level (Cmpbell et l., 1983; Kirchgessner et l., 1984). However, from these studies it cnnot be concluded whether the degree of compenstion is 1 The finncil support of Eurolysine S.A., Pris nd UT-Delfi B.V., Mrssen, nd the ssistnce of M. vn t End, P. L. vn der Togt, nd T. Zndstr re grtefully cknowledged. 2 To whom correspondence should be ddressed. Deprtmentl ddress: Mrijkeweg 40, 6709 PG Wgeningen. Received April 3, Accepted December 15, ffected by the level of feeding in the relimenttion period. In ddition, little informtion is vilble concerning the effect of previous restriction on the composition of body gin in the relimenttion period. This informtion is even more importnt becuse Koong et l. (1983) reported tht weights of metbolic orgns t slughter re significntly ffected by the feeding strtegy. Thus, it my be tht n increse in orgn gin ccounted for lrge prt of the compenstory gin in the reported studies. Therefore, in this study the effects of energy intke from 20 to 45 kg on performnce, tissue deposition, nd composition of gin between 45 nd 85 kg were studied in gilts t six levels of feeding from 45 to 85 kg. Experimentl Procedures Animls nd Design. Forty-eight 9- to 10-wk-old gilts of commercil hybrid (VOC Nieuw-Dllnd, Venry, The Netherlnds) with n verge live 806

2 ENERGY INTAKE AND BODY GAIN IN PIGS (45 85 KILOGRAMS) 807 weight of 21.8 ±.2 kg t the strt of the experiment were used in this study. These gilts were llocted on the bsis of BW mong 12 tretment combintions in 2 6 fctoril rrngement with four pigs per tretment combintion. The respective tretments were level of feeding from 20 to 45 kg, equivlent to 2.2 nd 3.7 times energy for mintennce ( M), nd level of feed intke from 45 to 85 kg, rnging from 1.7 times energy for mintennce to d libitum. The tretment period from 20 to 45 kg will be further referred to s the nutritionl history nd the gilts with the low (2.2 M) nd high (3.7 M) nutritionl history will be referred to s restricted nd control gilts, respectively. The tretment period from 45 to 85 kg will be referred to s the finishing period. Dietry Tretments. The six feeding levels in the finishing period were 1.7, 2.2, 2.7, 3.2, or 3.7 M, or d libitum. One experimentl diet, dequte in protein nd mino cids, ws used from 20 to 85 kg for ll tretment groups to ensure constnt dietry mino cid profile. This llowed the determintion of the reltionship between energy intke nd tissue deposition. The DE concentrtion of the diet ws mesured in digestibility tril using 10 intct mle pigs t BW of 30.7 ±.7 kg nd t BW of 65.7 ± 2.0 kg. These pigs were housed in metbolism cges nd received the experimentl diet t 2.2 or 3.7 times mintennce. Energy digestibility ws not ffected by the level of feed intke or by the BW of the gilt. The composition of the experimentl diet nd contents of digestible mino cids hve been published previously (Bikker et l., 1995). The energy content of the experimentl diet ws 15.1 MJ of DE/kg, crude protein content ws g/kg, nd totl nd ilel digestible lysine content were 11.3 nd 9.7 g/kg, respectively. Housing nd Mngement. The pigs were housed individully in pens with hlf-sltted floors in n insulted building t n ir temperture between 18 nd 22 C. The pigs were offered the experimentl diet in two equl portions per dy, t 0800 nd The diet ws pelleted nd offered in dry form. The pigs hd free ccess to wter. The pigs were weighed twice weekly, on Mondy nd Thursdy, before feeding, nd the dily feed llownces were djusted to expected gin for the following period of three or four dys, respectively. The feed llownces were bsed on metbolic body weight (BW.75 ), with digestible energy requirements for mintennce clculted s.475 MJ of DE per kg BW.75 (ARC, 1981). Feed refusls were collected nd weighed twice weekly. Bckft ws mesured ultrsoniclly t four points t the bck, t BW of 45 nd 85 kg. The verge of these points ws tken s the men bckft thickness per gilt (Verstegen et l., 1979). Slughter Procedures nd Crcss Anlysis. At live weight of 85 kg, the gilts were killed by electricl stunning nd exsnguintion. Body components were collected nd stored s described by Bikker et l. (1995). The bodies were dissected into eviscerted crcss nd orgns (orgn frction). The orgn frction comprised the blood nd ll orgns, including mesenteric ft. Empty body weight ws clculted s the sum of crcss nd orgn frction. Crcsses were dissected into trimmed mjor joints (referred to s len frction) nd other crcss prts (referred to s ft frction). The len frction comprised the hm, shoulder, nd loin, ll without subcutneous ft, nd met scrps. The len frction ws expressed s percentge in the empty body (body len percentge) nd in the crcss (crcss len percentge). The ft frction comprised ll other crcss prts nd consisted minly of bckft, belly ft, other ft depots, hed, feet, nd til (Bikker et l., 1995). The body composition of the pigs t 20 nd 45 kg ws estimted using the dt presented in Bikker et l. (1995), obtined with the sme dissection method. The ltter experiment from 20 to 45 kg ws conducted in the sme period, under similr experimentl conditions, nd with gilts from the sme herd s the present study. Sttisticl Anlysis. Regression nlysis on individul pig dt ws used to determine liner nd qudrtic effects of feed intke in the finishing period, on performnce, tissue deposition, nd body composition. The effects of nutritionl history on intercepts nd liner nd qudrtic terms were determined using dummy vribles nd bckwrd elimintion procedure, with P <.05 tken s boundry level (Drper Tble 1. Performnce of gilts from 20 to 45 kg t two feeding levels Feeding level, times mintennce energy Item Restricted (2.2 M) Control (3.7 M) SEM Effect b Dys in experiment *** DE intke, MJ/d *** ADG, g/d *** Gin/feed, g/kg *** Bckft, mm *** Dt re mens of 24 individully fed gilts. b Effect of energy intke, ***P <.001.

3 808 BIKKER ET AL. Restricted gilts: ADG = 550 ( ± 167) ( ± 11.4) DEI.44 ( ±.18) DEI 2 [1] Control gilts: ADG = 550 ( ± 167) ( ± 11.2) DEI.44 ( ±.18) DEI 2 [1b] Figure 1. Averge dily gin from 45 to 85 kg t six levels of energy intke in gilts tht hd received either 2.2 (restricted pigs) or 3.7 (control pigs) times energy for mintennce from 20 to 45 kg. nd Smith, 1981). Dt were nlyzed by the liner (GLM) regression procedure of SAS (1989). Results Performnce. In the growing period from 20 to 45 kg, dily gin of the control gilts ws much higher ( P <.001) thn tht of the restricted gilts, 959 vs 501 g/d (Tble 1). As result, the restricted gilts were 22 d older t the strt of the finishing period. In ddition, these gilts hd less bckft ( P <.001, Tble 1) nd higher ( P <.01) estimted body len percentge, 53.9 vs 47.4% (Bikker et l., 1995) t 45 kg. In the finishing period, the verge DE intke t the different intke levels incresed from 18.3 to 44.8 MJ/d for the restricted gilts nd from 18.0 to 41.9 MJ/ d for the control gilts (Tble 2). Dily gin incresed curvilinerly with incresing energy intke to 1,412 nd 1,201 g/d for the restricted nd control gilts, respectively. Gin/feed lso incresed curvilinerly with incresing DE intke. The first increments in energy level led to lrge increse in feed efficiency, which remined reltively constnt t the three highest energy levels. The rte nd efficiency of empty body gin lso incresed curvilinerly. The restricted gilts showed better performnce in this period thn the control gilts, which is reflected by n effect of the nutritionl history on the liner component of the reltionships for ADG, gin/feed, nd rte nd efficiency of the empty body gin. This implies tht the difference between control nd restricted gilts incresed with incresing levels of energy intke (DEI), which is illustrted for ADG (grms/dy) in Figure 1. These reltionships were described s follows: with r 2 =.943 nd RSD = 80.8 for the two equtions. The coefficient for the liner component ws 3.8 ±.74 ( P <.001) higher for the restricted thn for the control gilts. On verge, ADG nd gin/feed between 45 nd 85 kg were 138 g/d nd 49 g/kg higher for the restricted gilts. However, results in Tble 3, in which the finishing period ws divided in two periods of 20 kg, showed tht this improved gin nd efficiency were only evident from 45 to 65 kg of BW. Bckft thickness incresed linerly with incresing feeding level (Tble 2) nd ws on verge 1.6 mm higher for the control gilts. This difference incresed with incresing energy intke (Tble 2). Body Composition. Empty body weight s percentge of live weight t slughter (85 kg) ws not ffected by the level of energy intke nd ws slightly higher (.7%) in the control gilts (Tble 4). Weight of the crcss s proportion of the empty body decresed linerly nd the orgn weight incresed linerly with incresing feeding level. The len frction s percentge of the empty body nd s percentge of the crcss decresed curvilinerly with incresing energy intke, wheres the ft frction incresed curvilinerly. The len tissue s percentge of both the empty body nd the crcss ws on verge 2 to 3% higher in the restricted gilts thn in the control gilts. The percentge of ft tissue ws 2 to 3% higher in the control gilts. Tissue Deposition. The deposition rte of orgn tissue incresed linerly ( P <.001) with incresing energy intke, from 46 g/d to 244 g/d for the restricted gilts nd from 37 to 166 g/d for the control gilts (Tble 5). Consequently, there ws n incresing difference ( P <.001) between the restricted nd control gilts with incresing energy intke. Deposition rtes of crcss nd of len nd ft tissue incresed curvilinerly with incresing energy intke in the finishing period. On verge, deposition rtes of both len nd ft were 15 g/d higher (not significnt, P >.05) in the restricted gilts. The efficiency of len tissue deposition (grms/kilogrm) decresed qudrticlly with incresing energy intke (Tble 5). This efficiency ws reltively constnt t the three highest feeding levels nd ws not ffected by the nutritionl history of the gilts. The composition of body gin ws ffected by energy level nd nutritionl history. In Tble 6 the reltive contribution of gin of crcss, orgns, len, nd ft tissue to the empty body gin is given. The results showed n increse in the proportion of orgn nd ft gin nd lrge decrese, from pproximtely 58 to 40%, in the proportion of len tissue gin with

4 ENERGY INTAKE AND BODY GAIN IN PIGS (45 85 KILOGRAMS) 809 Tble 2. Energy intke nd performnce of gilts between 45 nd 85 kg t six levels of feed intke nd with two nutritionl histories Effects c Item nd history b d lib Men SEM DE intke History DE intke, MJ/d Restricted Control ADG, g/d Restricted L***Q* DL*** Control Gin/feed, g/kg Restricted L***Q*** DL*** Control Empty body gin, g/d Restricted L***Q** DL** Control EB gin/feed, g/kg Restricted L***Q*** DL** Control Bckft, mm Restricted L*** DL*** Control b Dt re mens of four individully fed gilts. Nutritionl history feeding level from 20 to 45 kg (2.2 [Restricted] or 3.7 [Control] times mintennce). Liner ( L ) nd qudrtic ( Q ) effect of energy intke between 45 nd 85 kg nd effect of the nutritionl history on the intercept (DI), liner ( DL), nd qudrtic ( DQ) component of the regression eqution. *P <.05, **P <.01, ***P <.001. incresing energy intke. Furthermore, t ech level of energy intke the proportion of orgn gin ws pproximtely 4% higher nd len gin ws pproximtely 3% lower in the restricted gilts. Overll Performnce from 20 to 85 Kilogrms. In Tble 7 re given the overll performnce nd len tissue deposition in the growing-finishing period. On verge, the restricted pigs needed 96 d, nd the control gilts 79 d, to grow from 20 to 85 kg. As consequence, the ge difference ws reduced from 22 d to 45 kg to 17 d t 85 kg due to the compenstory gin in the restricted gilts. The ADG between 20 nd 85 kg incresed linerly with incresing DE intke nd the liner component ws ffected by the nutritionl history. However, the verge dily energy intke ws much higher for the control gilts, 27.9 vs 21.9 MJ. Therefore, the effects of energy intke nd nutritionl history cnnot be derived directly from Tble 7. To illustrte these effects, the ADG between 20 nd 85 kg hs been plotted ginst DE intke, which is shown in Figure 2. At similr dily energy intkes, the restricted gilts gined bout 65 g/d fster thn the control gilts. Consequently, the gin/feed in the restricted gilts lso ws higher. The difference ws bout 40 g/ kg. However, the mximum dily gin in the control gilts ws 285 g/d higher thn in the restricted gilts, 1,123 vs 838 g/d, becuse of the lower energy intke of the restricted gilts. Further nlysis showed tht the extr ADG of 65 g/d in the restricted gilts comprised n increse in orgn gin of 21 g/d ( P <.001), n increse in ft gin of 18 g/d ( P <.01), nd n Figure 2. Averge dily gin from 20 to 85 kg in gilts fed t six energy levels between 45 nd 85 kg. The restricted nd control pigs received 2.2 nd 3.7 times energy for mintennce from 20 to 45 kg, respectively.

5 810 BIKKER ET AL. Tble 3. Energy intke nd performnce of gilts from 45 to 65 kg nd from 65 to 85 kg t six levels of feed intke nd with two nutritionl histories Effects c Item nd history b d lib Men SEM DE intke History kg DE intke, MJ/d Restricted Control ADG, g/d Restricted L*** DL*** Control Gin/feed, g/kg Restricted L***Q** DL*** Control kg DE intke, MJ/d Restricted Control ADG, g/d Restricted L***Q* Control Gin/feed, g/kg Restricted L***Q*** Control b Dt re mens of four individully fed gilts. Nutritionl history feeding level from 20 to 45 kg (2.2 [Restricted] or 3.7 [Control] times mintennce). Liner ( L ) nd qudrtic ( Q ) effects of energy intke between 45 nd 65 kg nd between 65 nd 85 kg nd effect of the nutritionl history on the intercept ( DI), liner ( DL), nd qudrtic ( DQ) component of the regression eqution. *P <.05, **P <.01, ***P <.001. increse in len gin of 14 g/d (not significnt, P >.05). Thus, t similr overll dily energy intke, the nutritionl history did not ffect ( P >.05) the dily len tissue deposition or the efficiency of len gin (Tble 7). Becuse of the increse in deposition rtes of other tissues, the body len percentge t similr verge energy intkes between 20 nd 85 kg ws 1.6% lower in the restricted gilts (Figure 3). Discussion Figure 3. Percentge of len tissue in the empty body of gilts t 85 kg fed t six energy levels between 45 nd 85 kg. The restricted nd control pigs received 2.2 nd 3.7 times energy for mintennce from 20 to 45 kg, respectively. In the discussion, the effects of energy intke between 45 nd 85 kg on body gin, efficiency of gin, nd body composition re discussed first. Therefter, the effects of the nutritionl history on performnce nd tissue deposition re discussed. Finlly, ttention is pid to the overll performnce between 20 nd 85 kg of BW. Effect of Energy Intke Between 45 nd 85 Kilogrms. Dily gin incresed with incresing energy intke. The increse per megjoule of DE decresed with incresing body weight. On verge, ADG incresed by 34.2 ± 1.5 g/mj of DE intke in the present study.

6 ENERGY INTAKE AND BODY GAIN IN PIGS (45 85 KILOGRAMS) 811 Tble 4. Body composition of gilts t 85 kg fed t six levels of feed intke between 45 nd 85 kg nd with two nutritionl histories Effects d Frction b nd history c d lib Men SEM DE intke History Empty body, % Restricted NS DI** Control , Crcss, % Restricted L*** Control Orgns, % Restricted L*** Control Len, % Restricted L***Q* DL*** Control Ft, % Restricted L**Q* DL*** Control Len in crcss, % Restricted L**Q* DL*** Control b Dt re mens of four individully fed gilts. Empty body weight (sum of crcss nd orgn frction) s percentge of live weight nd weight of crcss, orgns, len, nd ft tissue s percentge of empty body weight. Nutritionl history feeding level from 20 to 45 kg (2.2 [Restricted] or 3.7 [Control] times mintennce). Liner ( L ) nd qudrtic ( Q ) effects of energy intke between 45 nd 85 kg nd effect of the nutritionl history on the intercept (DI), liner ( DL), nd qudrtic ( DQ) component of the regression eqution. NS, not significnt, P >.05, *P <.05, **P <.01, ***P <.001. For gilts from 20 to 45 kg, Bikker et l. (1995) reported liner increse in ADG of 43.6 ± 2.2 g/mj of DE. The men slope for len growth (g/mj of DE) decresed from 12.5 ± 3.1 for pigs of 20 to 45 kg to 9.6 ± 1.0 for pigs of 45 to 85 kg. Consequently, the mrginl efficiency of body nd len tissue gin (g/mj of DE) decresed with incresing body weight, presumbly becuse older pigs deposit more lipid nd less protein per unit of extr energy (Bikker et l., 1996). A smll qudrtic effect ws present in the reltionship between energy intke nd body nd len tissue gin ( P <.05). Results in Tble 3 indicte tht this qudrtic effect on tissue deposition ws only present fter 65 kg. The curviliner effect indictes tht either plteu in len tissue growth rte ws reched or tht the slope for len tissue growth decresed grdully with incresing energy intke. The results do not clerly show tht plteu in len tissue gin ws reched. Furthermore, grdully decresing slope cn be explined by decresing proportion of len gin in the totl body gin (Tble 6), nd(or) by chnge in composition of the len tissue. Diminishing returns of len tissue gin with feed intke were lso reported by Knis (1988). The decrese of the len proportion in the gin (Tble 6) showed tht t low intke levels the pigs hve preference for muscle gin, wheres the proportion of ft tissue gin increses t higher intke levels. This is in greement with Dvies (1983), who reported tht pigs t high feeding level deposited proportiontely more ft nd less muscle reltive to pigs t low feeding level. In ddition to the incresing proportion of ft tissue gin, the reltive orgn gin lso incresed with incresing feed intke (Tble 6). This ws minly the result of growth of the liver, kidneys, nd digestive trct. An increse in the weights of metboliclly ctive orgns with incresing feed intke lso ws reported by Koong et l. (1982, 1983), Dvies (1983), Ro nd McCrcken (1992), nd Bikker et l. (1995). This effect presumbly reflects functionl hypertrophy of the orgns in order to process the incrementl mounts of feed nd illustrtes the dptive cpcity of the gilt to nutrient intke. As consequence of the decresing proportion of len gin, the len percentge in the body t 85 kg decresed by.3% per MJ of DE intke, with concomitnt increse in bckft (Tble 2) nd ft tissue content (Tble 4). An increse in len nd

7 812 BIKKER ET AL. Tble 5. Tissue deposition rtes nd efficiency of len gin in gilts between 45 nd 85 kg fed t six levels of feed intke nd with two nutritionl histories Effects c Item nd history b d lib Men SEM DE intke History Crcss, g/d Restricted L***Q** Control Orgns, g/d Restricted L*** DL*** Control Len, g/d Restricted L**Q* Control Ft, g/d Restricted L***Q* Control Len/feed, g/kg Restricted Q** Control b Dt re mens of four individully fed gilts. Nutritionl history feeding level from 20 to 45 kg (2.2 [Restricted] or 3.7 [Control] times mintennce). Liner ( L ) nd qudrtic ( Q ) effects of energy intke between 45 nd 85 kg nd effect of the nutritionl history on the intercept (DI), liner ( DL), nd qudrtic ( DQ) component of the regression eqution. *P <.05, **P <.01, ***P <.001. Tble 6. Composition of body gin in gilts between 45 nd 85 kg fed t six levels of feed intke nd with two nutritionl histories Effects d Frction b nd history c d lib Men SEM DE intke History Crcss, % Restricted L*** DI*** Control Orgns, % Restricted L*** DI*** Control Len, % Restricted L***Q* DI* Control Ft, % Restricted L**Q* Control Len in crcss, % Restricted L**Q* Control b Dt re mens of four individully fed gilts. Percentge of crcss, orgns, len, nd ft tissue in the empty body gin nd percentge of len tissue in the crcss gin. Nutritionl history feeding level from 20 to 45 kg (2.2 [Restricted] or 3.7 [Control] times mintennce). Liner ( L ) nd qudrtic ( Q ) effects of energy intke between 45 nd 85 kg nd effect of the nutritionl history on the intercept (DI), liner ( DL), nd qudrtic ( DQ) component of the regression eqution. *P <.05, **P <.01, ***P <.001.

8 ENERGY INTAKE AND BODY GAIN IN PIGS (45 85 KILOGRAMS) 813 Tble 7. Overll performnce of gilts from 20 to 85 kg fed t two feeding levels between 20 nd 45 kg nd t six feeding levels from 45 to 85 kg Effects c Item nd history b d lib Men SEM DE intke History DE intke, MJ/d Restricted Control Dys in experiment Restricted Control ADG, g/d Restricted L*** DL** Control Gin/feed, g/kg Restricted L**Q** DI** Control Len gin, g/d Restricted L*** Control Len/feed, g/kg Restricted Q** Control b Dt re mens of four individully fed gilts. Nutritionl history feeding level from 20 to 45 kg (2.2 [Restricted] or 3.7 [Control] times mintennce). Liner ( L ) nd qudrtic ( Q ) effects of energy intke between 20 nd 85 kg nd effect of the nutritionl history on the intercept (DI), liner ( DL), nd qudrtic ( DQ) component of the regression eqution. **P <.01, ***P <.001. decrese in ft percentge with reduction in energy intke lso ws reported by Ellis et l. (1983), Jørgensen et l. (1985), nd Susenbeth nd Keitel (1988), but not by Ro nd McCrcken (1992). As discussed by Bikker et l. (1995), the effect of reduction of energy intke on body composition depends on the genotype of the pig nd the level of energy intke. The ltter ws confirmed by the presence of curviliner effect of DE intke on len nd ft percentge in this study. In greement with Knis (1988) nd Bikker et l. (1995), the efficiency of len tissue gin decresed with incresing energy intke. Becuse of curviliner increse in gin/feed with incresing energy intke, the highest len efficiency ws reched t lower intke level thn the mximum efficiency of body gin. This is lso lrgely in greement with Ellis et l. (1983), who reported n increse in gin/feed with incresing feed intke, wheres len efficiency ws constnt or tended to decrese. In conclusion, the results of the present study showed n increse in the proportion of orgn nd ft tissue nd decrese in the proportion of len tissue with incresing energy intke. Consequently, the rtio of ft:len increses substntilly with n increse in the level of energy intke, even when the mximum rte of len deposition hs not been reched. As result, the len percentge nd efficiency of len gin re optimized t lower feed intke levels thn dily gin, gin/feed, nd len tissue growth rte. Effect of the Nutritionl History on Performnce from 45 to 85 Kilogrms. At the end of the restriction period t BW of 45 kg, the pigs on the low feeding level were 22 d older nd hd lener bodies thn the control pigs. From 45 to 85 kg these restricted pigs showed higher dily gin thn the control pigs (Tble 2). This difference in ADG incresed with incresing energy intke. The difference ws very smll t the two lowest feeding levels nd higher t the other four intke levels. Becuse of similr intkes of restricted nd control pigs, this compenstory gin ws cused by n incresed gin/feed (Tble 2). For the pigs with free ccess to feed, the increse in DE intke of pproximtely 3 MJ/d would lso hve contributed to the higher gin in these tretment groups. An incresed feed intke nd dily gin fter period of feed restriction ws lso reported by Nielsen (1964), Owen et l. (1971), nd Donker et l. (1986). This literture does not llow determintion to be mde s to whether the compenstory growth ws cused by the incresed feed intke or by n incresed efficiency. However, in the studies of Nielsen (1964), Cmpbell

9 814 et l. (1983), nd Kirchgessner et l. (1984), previously restricted pigs showed compenstory gin nd gin/feed t dily feed intke similr to tht of their non-restricted counterprts. These uthors reported n increse in dily gin of pproximtely 80 to 100 g/d fter restriction to 55 to 75% of the control feeding level for severl weeks. These references nd the present study show tht the rte of gin nd feed efficiency re higher fter period of feed restriction. In ddition, the present study shows tht this compenstion increses with incresing energy intke in the relimenttion phse. Nutrition nd Gin in Body Components. In the present study, the restricted gilts gined on verge pproximtely 140 g/d more between 45 nd 85 kg. A lrge prt of this extr gin ws cused by incresed gut fill (50 g/d, Tble 2) nd incresed orgn growth (50 g/d, Tble 5). The gin of len tissue, which is the most importnt edible product, ws only 15 g/d (not significnt) higher in the restricted gilts. The efficiency of len gin lso ws not ffected by the nutritionl history. In most of the bove-mentioned studies, the deposition of different tissues ws not determined. However, Mersmnn et l. (1987) nd Pond nd Mersmnn (1990) reported n incresed gin of liver, kidneys, nd the digestive trct in pigs during the rehbilittion period, without significnt compenstion in body or crcss gin. Furthermore, the dt of Drouillrd et l. (1991) in energyrestricted nd refed lmbs suggested smll compenstion in non-viscerl tissue nd lrger compenstion in viscerl tissue. Crstens et l. (1991) reported compenstory growth in steers tht were previously restricted in feed intke. This compenstion consisted of gut fill nd non-crcss wter nd protein. Consequently, these results indicte tht the compenstory gin fter period of feed restriction is lrgely cused by functionl increse in orgn growth nd in the contents of the intestinl trct. It hs been suggested tht crcss len percentge is higher in pigs fter period of restriction nd compenstion (Robinson, 1964). This ws confirmed by this study, becuse the restricted pigs hd less bckft nd ft tissue nd higher len percentge t 85 kg (Tble 4). Similr results were reported by Nielsen (1964), Cmpbell et l. (1983), nd Mersmnn et l. (1987). However, from the literture it cnnot be concluded whether the improved crcss qulity is direct result of the feed restriction in the restriction phse or is n effect of this restriction on the composition of gin during relimenttion. This study shows tht the higher crcss qulity of the restricted pigs ws not cused by n increse in len gin. Moreover, the proportion of len gin in the totl gin from 45 to 85 kg ws even lower in the restricted pigs thn in the control pigs, becuse of the incresed orgn growth (Tble 6). The higher percentge of len tissue in the crcss of the restricted gilts t 85 kg BIKKER ET AL. ws lredy present t 45 kg, due to the restriction in feed intke from 20 to 45 kg. The len percentge ws still higher t 85 kg becuse of the lck of compenstion in len or ft tissue gin. This my hve been the reson for the lower ft content in the other studies, becuse composition of gin ws not reported (Nielsen, 1964; Cmpbell et l., 1983), or no compenstion in len nd ft deposition ws found (Mersmnn et l., 1987). Presumbly, the bove-mentioned compenstion took plce during the first few dys or weeks of the relimenttion period, becuse compenstion in gin ws only present between 45 nd 65 kg. It seems resonble to ssume tht the metboliclly ctive orgns dpt to the incresed feeding level very soon fter the strt of the relimenttion period. This is in greement with Owen et l. (1971), who found the highest increse in gin immeditely fter the end of the restriction period. The energy requirements for this extr gin my be smll, becuse it minly consisted of wter nd protein (Bikker et l., 1996). Presumbly, the mintennce requirements were somewht lower during the first dys of the relimenttion period, becuse period of undernutrition cn reduce the bsl energy expenditure (Ledger nd Syers, 1977; Koong et l., 1983; Ferrell et l., 1985). When feed intke is restored, both the mintennce requirements nd the energetic efficiency of gin return rpidly to tht of the continuously fed pig (Grhm nd Serle, 1975; Webster, 1979; Schnyder et l., 1982). Furthermore, feed nd protein intke stimulte growth of certin viscerl tissues by suppressing protein degrdtion (Reeds, 1989), which thereby enbles n efficient regrowth of these tissues. Overll Performnce from 20 to 85 Kilogrms. The overll performnce from 20 to 85 kg shows the combined effects of energy intke on performnce between 20 nd 45 kg nd between 45 nd 85 kg. As expected, ADG nd gin/feed incresed with incresing energy intke. Furthermore, the restricted pigs were on verge 17 d older t 85 kg, which mens tht only 5 d of the time-lg of 22 d were compensted for by the compenstory gin nd feed efficiency. From the results in Tble 7 nd Figures 2 nd 3 it ws concluded tht t similr verge dily energy intke the distribution of the intke hd n effect on rte of gin nd body composition. The rte nd efficiency of body gin were higher in the pigs with low intke from 20 to 45 kg nd high intke from 45 to 85 kg thn in pigs with high intke from 20 to 45 kg nd low intke from 45 to 85 kg. This cn be explined by the higher verge metbolic body weight nd, consequently, the higher mintennce requirements of the pigs with the high intke nd dily gin below 45 kg (Wenk et l., 1980). At similr verge dily energy intke, the men metbolic body weight between 20 nd 85 kg ws 2.2 to 2.6 kg less for the restricted pigs, which llowed them to use 1 to 1.3 MJ of DE/d more

10 ENERGY INTAKE AND BODY GAIN IN PIGS (45 85 KILOGRAMS) 815 for tissue deposition. This lrgely explins the higher dily gin nd gin/feed of these pigs. The len percentge ws lower in the restricted pigs thn in the control pigs, t similr energy intke, minly becuse of higher orgn mss t 85 kg in restricted pigs. This indictes tht orgn mss t slughter is ffected more by the feeding level in the period just before slughter thn by the feeding level in erlier life, which is in greement with results of Koong et l. (1982, 1983) in pigs nd Ferrell et l. (1985) in lmbs. The overll dily len gin ws not significntly different for restricted nd control pigs (Tble 7), indicting tht the extr gin in restricted pigs is of limited benefit for pig production. As result, t similr verge dily intkes, the distribution of the dietry energy between the growing nd finishing phse of these gilts seems of little importnce for pig production. However, mximum ttinble gin of the body nd len tissue is of course much higher if pigs receive high feeding level both in the grower nd finisher period (Tble 7, Figure 2). In conclusion, this study showed tht fter period of feed restriction compenstory gin nd feed efficiency incresed with incresing feeding level in the relimenttion period. This extr gin ws lrgely ccounted for by n increse in the contents of the digestive trct nd by the incresed growth of metboliclly ctive orgns, which responded to the increse in feed intke. The higher crcss qulity t slughter in restricted nd relimented pigs ws cused by the restriction per se nd not by n effect of previous restriction on the composition of gin in the relimenttion period. Implictions Len tissue percentge nd efficiency of len tissue gin decresed with incresing energy intke. Giving pigs free ccess to feed will therefore optimize body nd len tissue gin but not body composition nd efficiency of len gin. After feed restriction in the growing period, pigs show compenstion in the rte nd efficiency of body gin, which is minly cused by n increse in orgn growth. The better crcss composition of compensting pigs is the result of mintining the better crcss composition present t the strt of the relimenttion phse. As result, compenstory gin fter period of feed restriction is of limited vlue for the pig industry. Literture Cited ARC The Nutrient Requirements of Pigs. Commonwelth Agric. Bureux, Slough, U.K. Bikker, P., V. Krbins, M.W.A. Verstegen, nd R. G. Cmpbell Protein nd lipid ccretion in body components of growing gilts (20 to 45 kilogrms) s ffected by energy intke. J. Anim. Sci. 73:2355. Bikker, P., M.W.A. Verstegen, nd R. G. Cmpbell Performnce nd body composition of finishing gilts (45 to 85 kilogrms) s ffected by energy intke nd nutrition in erlier life: II. Protein nd lipid ccretion in body components. J. Anim. Sci. 74:817. Cmpbell, R. G., nd M. R. Tverner Genotype nd sex effects on the reltionship between energy intke nd protein deposition in growing pigs. J. Anim. Sci. 66:676. Cmpbell, R. G., M. R. Tverner, nd D. M. Curic Effects of feeding level from 20 to 45 kg on the performnce nd crcss composition of pigs grown to 90 kg live weight. Livest. Prod. Sci. 10:265. Crstens, G. E., D. E. Johnson, M. A. Ellenberger, nd J. D. Ttum Physicl nd chemicl components of the empty body during compenstory growth in beef steers. J. Anim. Sci. 69: Dvies, A. S Growth nd development of pigs: A renlysis of the effects of nutrition on body composition. J. Agric. Sci. 100: 681. De Greef, K. H., nd M.W.A. Verstegen Prtitioning of protein nd lipid deposition in the body of growing pigs. Livest. Prod. Sci. 35:317. Donker, R. A., L. A. den Hrtog, E. W. Brscmp, J.W.M. Merks, G. J. Noordewier, nd G.A.J. Buiting Restriction of feed intke to optimize overll performnce nd composition of pigs. Livest. Prod. Sci. 15:353. Drper, N. R., nd H. Smith Applied Regression Anlysis (2nd Ed.). John Wiley & Sons, New York. Drouillrd, J. S., T. J. Klopfenstein, R. A. Britton, M. L. Buer, S. M. Grmlich, T. J. Wester, nd C. L. Ferrell Growth, body composition, nd viscerl orgn mss nd metbolism in lmbs during nd fter metbolizble protein or net energy restrictions. J. Anim. Sci. 69:3357. Ellis, M., W. C. Smith, R. Henderson, C. T. Whittemore, R. Lird, nd P. Phillips Comprtive performnce nd body composition of control nd selection line Lrge White pigs. 3. Three low feeding scles for fixed time. Anim. Prod. 37:253. Ferrell, C. L., L. J. Koong, nd J. A. Nienber Effect of previous nutrition on body composition nd mintennce energy costs of growing lmbs. Br. J. Nutr. 56:595. Grhm, N. McC., nd T. W. Serle Studies of wener sheep during nd fter period of weight stsis. 1. Energy nd nitrogen utiliztion. Aust. J. Agric. Res. 26:343. Jørgensen, J. N., J. A. Fernández, H. H. Jørgensen, nd A. Just Antomicl nd chemicl composition of femle pigs nd brrows of Dnish Lndrce relted to nutrition. J. Anim. Physiol. Anim. Nutr. 54:253. Knis, E Effect of verge dily food intke on production performnce in growing pigs. Anim. Prod. 46:111. Kirchgessner, M., F. X. Roth, nd E. Senckenberg Einfluß einer Protein- und/oder Energierestriktion und Relimenttion uf die N-Bilnz von Mstschweinen. J. Anim. Physiol. Anim. Nutr. 52:173. Koong, L. J., J. A. Nienber, nd H. J. Mersmnn Effects of plne of nutrition on orgn size nd fsting het production in geneticlly obese nd len pigs. J. Nutr. 113:1626. Koong, L. J., J. A. Nienber, J. C. Peks, nd J. T. Yen Effects of plne of nutrition on orgn size nd fsting het production in pigs. J. Nutr. 112:1638. Ledger, H. P., nd A. R. Syers The utiliztion of dietry energy by steers during periods of restricted food intke nd subsequent relimenttion. 1. The effect of time on the mintennce requirements of steers held t constnt live weights. J. Agric. Sci. 88:11. Mersmnn, H. J., M. D. McNeil, S. C. Seidemn, nd W. G. Pond Compenstory growth in finishing pigs fter feed restriction. J. Anim. Sci. 64:752. Nielsen, H. E Effects in bcon pigs of differing levels of nutrition to 20 kg. body weight. Anim. Prod. 6:301. Owen, J. B., W. J. Ridgmn, nd D. Wyllie The effect of food

11 816 BIKKER ET AL. restriction on subsequent voluntry intke of pigs. Anim. Prod. 13:537. Pond, W. G., nd H. J. Mersmnn Differentil compenstory growth in swine following control of feed intke by highlflf diet fed d libitum or by limited feed. J. Anim. Sci. 68: 352. Ro, D. S., nd K. J. McCrcken Energy:protein interctions in growing bors of high genetic potentil for len growth. 1. Effects on growth, crcss chrcteristics nd orgn weights. Anim. Prod. 54:75. Reeds, P. J Regultion of protein turnover. In: D. R. Cmpion, G. R. Husmn nd R. J. Mrtin (Ed.). Animl growth regultion. p Plenum Press, New York. Robinson, D. W The plne of nutrition nd compenstory growth in pigs. Anim. Prod. 6:227. SAS SAS/STAT User s Guide (4th Ed.). SAS Inst. Inc., Cry, NC. Schnyder, W., H. Bickel, nd A. Schürch Energy metbolism during retrded nd compenstory growth of brunvieh steers. In: A. Ekern nd F. Sundstøl (Ed.) Energy Metbolism of Frm Animls. EAAP publ. no. 29. p 96. The Agric Univ. of Norwy. Susenbeth, A., nd K. Keitel Prtitioning of whole body protein in different body frctions nd some constnts in body composition in pigs. Livest. Prod. Sci. 20:37. Verstegen, M.W.A., G. Mtemn, H. A. Brndsm, nd P. I. Hrtsen Rte of gin nd crcss qulity in fttening pigs t low mbient tempertures. Livest. Prod. Sci. 6:51. Webster, A.J.F Discussion pper: metbolic responses in the growing niml. In: L. E. Mount (Ed.) Energy Metbolism. EAAP Publ. no. 26. p 461. Butterworths, London. Wenk, C., H. P. Pfirter, nd H. Bickel Energetic spects of feed conversion in growing pigs. Livest. Prod. Sci. 7:483.