Effect of dietary energy level on the performance of individually housed early-weaned piglets in relation to environmental temperature

Livestock Production Science, 14 (1986) 255--263 Elsevier Science Publishers B.V., Amsterdam -- Printed in The Netherlands

255

EFFECT OF DIETARY ENERGY LEVEL ON THE PERFORMANCE OF INDIVIDUALLY HOUSED EARLY-WEANED PIGLETS IN RELATION TO ENVIRONMENTAL TEMPERATURE

J. LE DIVIDICH and J. NOBLET Institut National de la Recherche Agronomique, Station de Recherches sur l'Elevage des Porcs, Centre de Rennes St Gilles, 35590 L 'Hermitage (France)

(Accepted 25 October 1985)

ABSTRACT Le Dividich, J. and Noblet, J., 1986. Effect o f dietary energy level on the performance o f individually housed early-weaned piglets in relation to environmental temperature. Livest. Prod. Sci., 14: 255--263. An experiment involving 72 individually housed piglets was conducted to determine the interactive effects of environmental temperature and dietary energy level on the performance of early-weaned piglets maintained for six weeks in environmental temperature o f 28, 22 or 16°C. Two diets were formulated to supply 3.1 (low energy diet) and 3.6 (high energy diet) Mcal digestible energy per kg of feed. The high-energy diet had greater (P < 0.01) energy and nitrogen digestibility than the low-energy diet. Digestibilities were similar in piglets exposed to 22 and 28°C and higher (P < 0.05) than in those housed at 16°C. Exposure to a low temperature (16°C) increased feed intake by 8% (P < 0.05) and feed to gain ratio by 11% (P < 0.01), whereas exposure to a warm environment (28°C) decreased feed intake by 25% (P < 0.01) and growth rate by 28% (P < 0.01) compared with piglets housed at thermal neutrality (22°C). The effect o f dietary energy level on the rate o f weight gain, DE intake and DE to gain ratio was dependent upon environmental temperature in which piglets were maintained. Compared with the high-energy diet, the low-energy diet depressed DE intake by 9.2% (P < 0.05) and rate of weight gain by 14.1% (P < 0.01) and increased DE to gain ratio b y 5.5% (P < 0.05) in piglets housed in the warm environment. Under cold conditions both low and high energy diets resulted in similar DE intake, rate of weight gain and DE to gain ratio.

INTRODUCTION V o l u n t a r y f e e d i n t a k e in p i g s h a s b e e n s h o w n t o b e r e l a t e d t o e n v i r o n m e n t a l t e m p e r a t u r e ( F u l l e r , 1 9 6 5 ; S u g a h a r a e t al., 1 9 7 0 ; V e r s t e g e n e t al., 1 9 7 8 ) . I n p i g s m a i n t a i n e d in a w a r m e n v i r o n m e n t t h e d e c r e a s e i n f e e d c o n s u m p t i o n is a s s o c i a t e d w i t h a r e d u c e d a m o u n t o f h e a t i n c r e m e n t o f f e e d i n g . I n c o n t r a s t , a c o l d e n v i r o n m e n t s t i m u l a t e s f e e d i n t a k e r e s u l t i n g in a n increased heat increment which can be used to compensate for some of the e x t r a t h e r m o r e g u l a t o r y h e a t p r o d u c t i o n t h a t o c c u r s in t h e c o l d ( V e r s t e g e n

0301-6226/86/$03.50

© 1986 Elsevier Science Publishers B.V.

256 et al., 1973; Noblet and Le Dividich, 1982; Close and Stanier, 1984). Heat increment is also related to the nutritive composition of the diet, with fibrous feedstuffs having a higher increment than fat sources (Hillcoat and Annison, 1974; Just et al., 1983). It follows therefore that growth of pigs maintained in environments below or above their zone of thermal neutrality can be increased or further depressed by the type of ingredient and energy level used in the diet. Literature data indicate that low energy diets (3.1--3.2 Mcal ME per kg) do not reduce growth rate of growing--finishing pigs under cold conditions, whereas high energy diets are superior in warm weather (Seerley et al., 1978; Stahly and Cromwell, 1979; Stahly et al., 1981; Coffey et al., 1982). However, there is no information available on the interaction of dietary energy density and air temperature in early-weaned pigs. Therefore, the present experiment was designed to determine the effect of dietary energy concentration on the performance of early-weaned pigs in relation to environmental temperature. MATERIAL AND METHODS An experiment involving a total of 72 animals was conducted to examine the effects of dietary energy density on the growth of early-weaned pigs that were maintained at an environmental temperature of 28, 22 or 16°C. The two experimental diets were composed of maize, barley and protein mixture fortified with minerals and vitamins (Table I). Dietary treatments were: (1) low energy diet (LE) based on barley with supplemental wheat bran; (2) high energy diet (HE) based on maize with supplemental beef tallow. Percentage composition of protein mixture was: soybean meal (75%), herring meal (15%) and dried skimmed milk (10%). Both diets were formulated to provide 50 g digestible protein and 3.5 g lysine per Mcal digestible energy (DE) so that the calorie : protein ratio was constant for the two diets. The experiment was conducted in three similar temperature-controlled rooms (4 X 3 m) which were equipped with six cages (1.2 X 0.6 m) at one level. Heating was provided by electric heaters, one being located in the inlet air duct to provide adequate cold and warm air mixture. The air temperature was regulated to within + 0.5°C at the level of the cage floor. Air moisture was not controlled, but relative humidity ranged between 60 and 80%. Air velocity was less than 10 cm s-~ at the level of the pigs. Water was available in each cage from nipple-type drinkers. Large White piglets were obtained from our experimental herd. For each of the four replicates, three litters were weaned simultaneously at 22 + 2 days of age. At weaning, six piglets were selected within each litter on the basis of weight and assigned in pairs to one of the temperature treatments. During the immediate post-weaning week, piglets were fed ad libitum a pelleted starter diet (Table I). In each temperature-controlled room, the

257 TABLE I Composition of diets Ingredient

Yellow corn, ground Barley, ground Tallow, bleachable fancy Wheat bran Soybean meal, dehulled Skimmed milk Herring meal 1-1ysine HCL Dicalcium phosphate Calcium carbonate Salt, iodized Trace mineral mix (with cornstarch) a Vitamins--additive mix (with cornstarch) b Analyzed level (as fed basis) Crude protein (%) Crude fibre (%) NDF (%) Gross energy (Mcal kg -1)

Starter

Experimental HE

LE

-55.15 3.00 -19.00 15.00 4.00 -1.40 1.30 0.30 0.42 0.43

56.50 -7.00 -~ 24.00 3.25 4.88 0.15 1.40 1.30 0.30 0.42 0.43

-56.11 3.00 12.00 18.75 2.50 3.75 0.04 1.40 1.30 0.30 0.42 0.43

100.00

100.00

100.00

23.00 --4.06

21.2 2.4 6.7 4.24

20.1 4.0 15.3 3.99

aContributed in mg per kilogram of diet: Mg, 24; Fe, 60; Zn, 57; Mn, 20; Cu, 10; Co, 2; I, 0.76. bContributed per kilogram of diet : vitamin A 5000 i.u.; vitamin D 3 1000 i.u.; vitamin E 20 i.u.; thiamin 2 rag; riboflavin 10 rag; pyridoxine 10 rag; ascorbic acid 20 rag; niacin 40 rag; choline 500 mg; vitamin B,2, 50 ~g; Mecadox 1 g.

air t e m p e r a t u r e was initially set at 28°C (Le Dividich et al., 1 9 8 2 ) and r e m a i n e d u n c h a n g e d (28°C t r e a t m e n t ) or was gradually r e d u c e d t o 22 or 16°C b y the seventh d a y post-weaning. O n the eighth d a y , piglets were weighed and allotted within each t e m p e r a t u r e - c o n t r o l l e d r o o m t o dietary t r e a t m e n t on the basis o f litter origin, w e i g h t and sex (in t h a t order o f p r i o r i t y ) f o r a six-week p e r i o d , during w h i c h piglets were fed ad libitum the e x p e r i m e n t a l diets. Average w e i g h t o f the piglets on the eighth day after t h e start o f the e x p e r i m e n t (i.e., o n the eighth d a y following weaning) was 7.15 + 0.7; 7.30 + 0.8 and 7.25 -+ 0.9 kg f o r the 28, 22 a n d 20°C treatm e n t s , respectively. Individual weight a n d feed c o n s u m p t i o n o f the piglets were r e c o r d e d w e e k l y . A p p a r e n t digestibility o f energy and n i t r o g e n was d e t e r m i n e d using titanious o x i d e as an indigestible m a r k e r (Njaa, 1 9 6 1 ) . Titanious o x i d e (0.5%) was a d d e d t o b o t h e x p e r i m e n t a l diets at the expense o f maize a n d

258

barley. These diets were fed for 14 days beginning on day 14 after the start of the experiment, with the first 10 days being the adjustment period and the last four days the collection period. During the collection period, fresh samples of faeces (70--80 g per piglet) were daily collected, placed in plastic bags and frozen. The pooled samples of faeces from each piglet were freezedried and ground. Feeds and freeze-dried faeces were analyzed for nitrogen by the macro-Kjeldahl method and gross energy using an adiabatic b o m b calorimeter. Titanious oxide was colorimetrically determined by the method described by Njaa (1961). The data were analyzed as a split-plot design, with environmental temperature considered as the whole plot and diet as the subplot (Cochran and Cox, 1966). The whole plot error term was used to test environmental temperature. The subplot error term was used to test diet and its interaction with environmental temperature. RESULTS

Apparent digestibilities of energy and nitrogen are shown in Table II. Digestibilities of the high energy diet (diet HE) were higher (P < 0.01) than those of the low energy diet (diet LE) in all of the three temperature treatments. Reducing the environmental temperature from 28 to 22°C did not influence digestibilities, but the decrease to 16°C caused a significant reduction (P < 0.05) in the digestibility of energy and nitrogen of both diets. The reduction was more pronounced (P <: 0.10) for diet LE than for diet HE. Consequently, at both 28 and 22°C, the pooled digestible energy (DE) values of diets HE and LE were 3.62 and 3.17 Mcal kg -~, respectively. At 16°C, the corresponding values were 3.55 and 3.03 Mcal kg -~. Daily feed intake and thus DE intake were quadratically decreased (P < 0.01) as environmental temperature was increased from 16 to 28°C (Table TABLE II Effect of environmental temperature and energy level on the apparent digestibility of energy and nitrogen

Temperature (°C)

28

22

16

S.E.M. b

Energy levela

HE

LE

HE

LE

HE

LE

Energy digestibility(%)cd Nitrogen digestibility (%)cd

85.5 84.0

79.1 81.4

85.1 83.8

80.0 81.3

83.7 81.8

76.0 78.2

0.4 0.6

aHE, high-energy diet; LE, low-energy diet. bStandard error of means. CEffect of energy level at the three environmental temperatures, (P < 0.01). dThe 16°C treatment was different (P < 0.05) from the 28 and 22°C treatments.

259 Ill). Daily weight gain and feed to gain ratio also responded quadratically (P < 0.01) to temperature. Exposure to 16°C increased feed intake (P < 0.05) and the a m o u n t of feed or DE required per unit of weight gain (P < 0.01) when compared with piglets housed in the 22°C environment, b u t did not influence daily weight gain. In contrast, piglets on the 28°C environm e n t exhibited a lower (P < 0.01) feed intake and rate of weight gain compared with piglets maintained at 22°C, but efficiency of feed or DE was n o t significantly different between the two temperature treatments. T A B L E III

E f f e c t o f e n v i r o n m e n t a l t e m p e r a t u r e a n d d i e t a r y e n e r g y level o n p e r f o r m a n c e a n d energy u t i l i z a t i o n in weaned piglets T e m p e r a t u r e (°C)

16

E n c r g y h'w~l a

LE

Dally g a i n (g)ce Daily feed i n t a k e , (g)Cf F e e d / g a i n cd DE i n t a k e a n d u t i l i z a t i o n Daily DE i n t a k e (Mcal) cg DE gain I(Mcal kg-I)c~

22

28

S.E .1~.

HE

LE

HE

LE

HE

593 1094 1.85

613 961 1.57

591 981 1.66

639 913 1.42

407 720 1.76

474 694 1.46

13 23 0.02

3.31 5.57

3.42 5.59

3.14 5.31

3.31 5.18

2.28 5.58

2.51 5.29

0.08 0.07

a H E , h i g h energy level; L E , l o w e n e r g y level. b s t a n d a r d error of means. C Q u a d r a t i c e f f e c t o f t e m p e r a t u r e (P <5 0.01 ). d E f f c e t o f energy level at the thrt, e e n ~ 4 r o n m e n t a l t e m p e r a t u r e s , (P <5 0 . 0 1 ) . e E f f e c t o f e n e r g y level a t 2 2 a n d 28>C, (P '~ 0 . 0 5 ) . f E f f i ' c t of e n e r g y level at 16 a n d 22°C, (P < 0 . 0 5 ) . g E f f e e t o f energy level at 2 8 C (P <, 0 . 0 5 ) .

An interaction between dietary energy level and environmental temperature on feed intake and rate of gain was observed. Feed intake was higher by 13.8% (P < 0.01) and 7.2% (P < 0.05) in piglets fed diet LE than in those fed diet HE, at 16 and 22°C, respectively. At 28°C, the difference (3.7%) was n o t significant. Feeding diet LE caused a significant reduction in DE intake at 28°C (P < 0.05) but not at 22 and 16°C. Diet LE p r o m o t e d a lower (P < 0.05) rate of weight gain than did diet HE at 28 and 22°C but not at 16°C. As expected, feeding diet LE was associated with a significant increase (P < 0.01) in feed to gain ratio at the three environmental temperatures. The quantity of DE required per unit of weight gain was not affected by the dietary energy level for the 16°C treatment, b u t increased in piglets fed the low~nergy diet as the temperature was increased, with the difference being significant (P < 0.05) at 28°C. DISCUSSION

From previous results (Le Dividich et al., 1982; McCracken and Gray, 1984) it was assumed that the 22°C temperature was within the thermoneutral zone of the individually housed piglets whereas the 16°C treatment

260

was below their lower critical temperature. The depressed feed to gain and DE to gain ratios observed at 16°C compared with those obtained at 22°C largely reflect the increased energy requirement for maintenance in the cold environment. The reduction in energy and nitrogen digestibility at the low environmental temperature is in agreement with the results obtained in growing-finishing pig (Fuller and Boyne, 1972; Phillips et al., 1 9 8 2 ) a n d sows (Hovell et al., 1977). However, a high level of feed intake has also been found to lower digestibility in weaned piglets (Leibholz, 1981; S~ve, 1982). In the present experiment, the level of feed intake when expressed as g kg -~ b o d y weight during the 14-day feeding diets with marker was 21 and 13% higher at 16°C than at 28 and 22°C, respectively. Therefore, as suggested by studies of Westra and Christopherson (1975) with sheep, the high level of feed intake associated with the low temperature may have resulted in a lower retention time of the diet in the digestive tract leading to a decrease in digestibility. However, further research is required to clarify the interactive effects of cold environment and level of feed intake on diet digestibility. Voluntary feed intake in piglets is known to be influenced by the energy concentration of the diet. Piglets fed a low energy diet consume more feed. However the extra feed intake is generally insufficient to achieve a DE intake similar to that of piglets fed a higher energy diet (Campbell et al., 1975; McConnell et al., 1982). In the present study, the similarity in DE intake and rate of gain observed in the cold (16°C) environment between piglets offered the low- and high-energy diets is in contrast with the sharp reduction found in piglets offered the low-energy diet in the warm environment (28°C). This suggests that over the dietary energy concentration range 3.1--3.6 Mcal per kg, the piglet adjusts the amount of feed consumed so that DE intake remains relatively constant when maintained in cold but not in warm conditions. In this regard, at high environmental temperature, energy intake appears to be a limiting factor for maximum performance. The fact that piglets fed the high-energy diet exhibited an increase in DE intake and rate of gain when housed at 28°C but not at 16°C indicates that an increased dietary energy level by inclusion of fat helps to counterbalance to some extent the reduction in voluntary feed intake occurring at high temperature. Similar observations have been made with older pigs by Stahly and Cromwell (1979) and Stahly et al. (1981). The improved feed efficiency in piglets fed the high-energy diet has been reported by others (Aumaitre et al., 1964; Campbell et al., 1975, McConnell et al., 1982). In addition, similar to observations made with growing--finishing pigs (Seerley et al., 1978; Stahly and Cromwell, 1979; Stahly et al., 1981; Coffey et al., 1982), our results indicate an improvem e n t in DE efficiency in piglets fed the high-energy diet under warm conditions (28°C) whereas both diets resulted in similar efficiency under cold conditions (16°C). This interaction is apparently related to the amount of

261 d i e t a r y h e a t i n c r e m e n t , w h i c h is inversely r e l a t e d t o t h e e n e r g y c o n c e n t r a t i o n o f the diet ( J u s t et al., 1 9 8 3 ) a n d p a r t l y u s e d f o r t h e r m o r e g u l a t i o n u n d e r cold c o n d i t i o n s b u t m u s t be dissipated u n d e r w a r m c o n d i t i o n s (Verstegen et al., 1 9 7 3 ; N o b l e t a n d Le Dividich, 1 9 8 2 ; Close a n d Stanier, 1984). T h e r e f o r e , t h e i m p r o v e d D E e f f i c i e n c y o b s e r v e d in t h e p r e s e n t s t u d y f o r t h e l o w - e n e r g y d i e t u n d e r cold c o n d i t i o n s reflects t h e increased a m o u n t o f h e a t i n c r e m e n t available f o r t h e r m o r e g u l a t i o n , w h e r e a s the r e d u c e d h e a t i n c r e m e n t associated w i t h the high-energy d i e t m a y have p a r t l y alleviated t h e d i s c o m f o r t o f t h e piglets u n d e r w a r m c o n d i t i o n s . It s h o u l d be m e n t i o n e d t h a t these results w e r e o b t a i n e d w i t h individually h o u s e d piglets. D u e t o t h e f a c t t h a t increasing t h e g r o u p size lowers t h e critical t e m p e r a t u r e ( M o u n t , 1 9 7 5 ) , it is likely t h a t in piglets h o u s e d in g r o u p s t h e e f f e c t s o b s e r v e d herein m a y be lessened at l o w t e m p e r a t u r e s a n d e n h a n c e d at high t e m p e r a t u r e s . ACKNOWLEDGEMENTS

T h e a u t h o r s t h a n k Miss O. L e m e l e a n d Mr J. L e b o s t f o r t e c h n i c a l assist a n c e a n d Mr J. G a u t h i e r f o r h u s b a n d r y o f t h e animals.

REFERENCES Aumaitre, A., Jouandet, C. and Salmon-Legagneur, E., 1964. Effect des taux ~nerg~tique et protidique de la ration sur l'efficacitdalimentalre et sur la croissance chez le porcelet. Ann. Zootech., 38: 285--253. Campbell, R.G., Taverner, M.R. and Mullaney, P.D., 1975. The effect of dietary concentrations of digestible energy on the performance and carcass characteristics of early-weaned piglets.Anita. Prod., 21: 285--294. Close, W.H. and Stanier, M.W., 1984. Effects of plane of nutrition and environmental temperature on the growth and development of early-weaned piglets. 2. Energy metabolism. Anita. Prod., 38 : 221--231. Cochran, W.G. and Cox, G.M., 1966. Experimental designs. (2nd edn.). John Wiley, N e w York. Coffey, M.T., Seerley, R.W., Funderburke, D.W. and McCampbell, H.C., 1982. Effect of heat increment and level of dietary energy and environmental temperature on the

performance of growing--finishing swine. J. Anim. Sci., 54: 95--105. Fuller, M.F., 1965. The effect of environmental temperature on the nitrogen metabolism and growth in the young pig. Br. J. Nutr., 19: 531--546. Fuller, M.F. and Boyne, A.W., 1972. The effects of environmental temperature on the growth and metabolism of pigs given different amounts of food 2. Energy metabolism. Br. J. Nutr., 28: 373--384. Hillcoat, J.B. and Annison, E.F., 1974. The efficiency of utilization of diets containing maize oil, tallow and tallow acid oil in the pig. In: Menke, K.H., Lantzsch, H.J. and Reichl, J.R. (Editors), Energy Metabolism of Farm Animals. E.A.A.P. Publication No. 14, pp. 177--170. Hovell, F.D.D., Gordon, J.G. and McPherson, R.M., 1977. Thin sows 2. Observations on the energy and nitrogen exchanges of thin and normal sows in environmental temperatures of 20 and 5°C. J. Agric. Sci., 89: 523--533.

262 Just, A., Fernandez, J.A. and Jorgensen, H., 1983. The net energy value of diets for growth of pigs in relation to the fermentative processes in the digestive tract and the site of absorption of the nutrient. Livest. Prod. Sci., 10: 171--186. Le Dividich, J., Noblet, J. and Aumaitre, A., 1982. Environmental requirements of early weaned intensively reared piglets. In: Livestock Environment II. A S A E Publication 3-82, pp. 353--361. Leibholz, J., 1981. Tryptophane requirements of pigs between 28 and 56 days of age. Aust. J. Agric. Res., 32: 845--850. McCracken, K. and Gray, R., 1984. Further studies on the heat production and effective lower critical temperature of early-weaned pigs under commercial conditions of feeding and management. Anita. Prod., 39: 283--290. McConnell, J.C., Stuck, M.W., Waldorf, R.C., Byrd, W.A. and Grimes, L.W., 1982. Caloric requirement of early-weaned pigs fed corn--soybean meal-based diets. J. Anita. Sci., 55: 841--847. Mount, L.E., 1975. The assessment of thermal environment in relation to pig production. Livest. Prod. Sci., 2: 381--392. Njaa, J., 1961. Determination of protein digestibility with titanious oxide as indicator substance. Acta Agric. Scand., 9: 227--241. Noblet, J., and Le Dividich, J., 1982. Effect of environmental temperature and feeding level on energy balance traits of early-weaned piglets. Livest. Prod. Sci., 9: 619--632. Phillips, P.A., Young, B.A. and McQuitty, J.B., 1982. Liveweight, protein deposition and digestibility responses in growing pigs exposed to low temperature. Can. J. Anim. Sci., 62: 95--108. Seerley, R.W., McDaniel, M.C. and McCampbell, H.C.M., 1978. Environmental temperature influence on utilization of energy in swine diets. J. Anim. Sci., 42: 427. S~.ve, B., 1982. Preweaning nutrition of the young pig. Implications in feeding and development. Paper presented at the 33rd Annual Meeting of E.A.A.P., Leningrad. Stably, T.S. and Cromwell, G.L., 1979. Effect of environmental temperature and dietary fat supplementation on the performance and carcass characteristics of growing and finishing swine. J. Anim. Sci., 49: 1478--1488. Stahly, T.S. Cromwell, G.L. and Overfield, J.R., 1981. Interactive effects of season of year and dietary fat supplementation, lysine source and level on the performance of swine. J. Anita. Sci., 53: 1269--1277. Sugahara, M., Baker, D.H., Harmon, B.G. and Jensen, A.H., 1970. Effect of ambient temperature on performance and carcass development in young swine. J. Anita. Sci., 31: 59--62. Verstegen, M.W.A., Brascamp, E.W. and Van der Hel, W., 1978. Growing and fattening of pigs in relation to temperature of housing and feeding level. Can. J. Anim. Sci., 58: 1--13. Verstegen, M.W,A., Close, W.H., Start, I.B. and Mount, L.E., 1973. The effects of environmental temperature and plane of nutrition on heat loss, energy retention and deposition o f protein and fat in groups of growing pigs. Br. J. Nutr., 30: 21--35. Westra, R. and Christopherson, R.J., 1975. Effect of cold exposure on digestive function in sheep. University of Alberta, Feeders Day Report. No. 54, pp. 56--57.

RESUME Le Dividich, J. et Noblet, J., 1986. Influence de la concentration ~nerg~tique de la ration sur les performances de croissance du porcelet sevrd en relation avec la temperature ambiante. Livest. Prod. Sci., 14:255--263 (en anglais). Un essai portant sur u n effectif de 72 porcelets sevrds ~ environ trois semaines d'~ge a dt~ entrepris afin de d~tenniner les effets de la concentration ~nerg~tique de la ration

263 sur les performances de croissance des animaux maintenus fila temp6rature de 28, 22 ou 16°C. Deux aliments sont utilis6s, l'un dilud en dnergie (3.1 Kcal ED/g), ~ base d'orge et de son de blfi,l'autre, concentr~ en ~nergie (3.6 Kcal ED/g) est a base de maKs additionnfi de suif. Les porcelets sont 6levds individuellement et, fi l'issue d'une semaine apr6s le sewage, ils re~oivent a volont~ les aliments exp6rimentaux pendant six semaines. La digestibilitd apparente de l'dnergie et de l'azote des aliments est estim6e en utilisant l'oxyde de titane c o m m e marqueur. L'aliment dilud en ~nergie est moins digestible (P < 0.01) que l'aliment fiche en ~nergie. A 16°C, les digestibilit6s apparentes de l'dnergie et de l'azote sont significativem e n t plus faibles (P < 0.05) qu'~ 22 et 28°C. Par rapport aux r~sultats obtenus ~ 22°C, l'exposition des porcelets au froid (16°C) s'accompagne d'une augmentation significative de la quantitd d'aliment ing4rd (+ 8%, P < 0.05) et de l'indice de consommation (+ 11%, P < 0 . 0 ! ) ; au chaud (28°C), la consommation d'aliment est diminu~e de 25% (P < 0.01) et la vitesse de croissance de 28% (P < 0.01). I1 existe une interaction entre la concentration ~nergdtique de l'aliment et la tempdrature ambiante sur la vitesse de croissance, la quantit~ d'ED ing~r~e et l'indice de consommation exprim4e en Kcal ED/kg de gain de poids. A 28°C, les porcelets recevant l'aliment dilud en ~nergie ing~rent 9.2% d'ED de moins (P < 0.05) que ceux recevant l'aliment concentr4 en ~nergie et leur vitesse de croissance est infdrieure de 14.1% (P < 0.01) tandis que la quantitd d'ED par kg de gain de poids est accrue de 5.5% (P < 0.05). A l'oppos4, les performances observ~es 16°C sont semblables pour les deux aliments. KURZFASSUNG Le Dividich, J. und Noblet, J., 1986. Der Einfluss des Energiegehaltes im Futter auf die Leistung yon einzel gehaltenen und friihabgesetzten Ferkeln in Beziehung zur Umgebungstemperatur. Livest. Prod. Sci., 14:255--263 (auf englisch). Es wurde ein Versuch mit 72 einzeln gehaltenen Ferkeln durchgefiihrt, um die Wechselwirkungen zwischen der Umgebungstemperatur und dem Energiegehalt des Futters auf die Leistung frfihabgesetzter Ferkel zu untersuchen, die fiir 6 Wochen bei 28, 22 oder 16°C gehalten wurden. 2 Futtermischungen, eine mit 3.1 (energiearme Ration) und eine mit 3.6 (energiereiche Ration) Mcal verdaulicher Energie pro kg Futter kamen zu Einsatz. Die energiereiche Ration ergab eine hShere (P < 0.01) Energie- und Stickstoffverdaulichkeit als die energiearme Ration. Die Verdaulichkeiten waren bei den Ferkeln, die bei 22 und 28°C gehalten wurden, gleich gut und besser (P < 0.05) als bei den Ferkeln, die bei 16°C gehalten wurden. Wenn die Ferkel bei einer niedrigen Temperatur (16°C) gehalten wurden, stiegen die Futteraufnahme um 8% (P < 0.05) und der Futterverbrauch je kg Zuwachs um 11% an (P < 0.01), w~'hrend sich bei einer hohen Umgebungstemperatur (28°C) die Futteraufnahme um 25% (P < 0.01) und die Wachstumsrate um 28% (P < 0.01) verringerte-verglichen mit Ferkeln, die bei neutraler Temperatur (22°C) gehalten wurden. Der Einfluss der Energiekonzentration auf Wachstumsrate, Aufnahme an verdaulicher Energie und Verbrauch an verdaulicher Energie je kg Zuwachs war yon der Umgebungstemperatur abh~ngig, bei der die Ferkel gehalten wurden. Im Vergleich zur energiereichen Ration, waren bei der energiearmen Ration die Aufnahme an verdaulicher Energie um 9.2% (P < 0.05) und die Wachstumsrate um 14.1% (P < 0.01) vermindert und der Verbrauch an verdaulicher Energie je kg Zuwachs um 5.5% (P < 0.05) erh6ht, wenn die Ferkel in warmer Umgebung gehalten wurden. Bei niedrigen Temperaturen waren Aufnahme an verdaulicher Energie, Wachstumsrate und Verbrauch an verdaulicher Energie je kg Zuwachs bei der energiearmen und der energiereichen Ration gleich.