COMMERCIAL LAYING HENS'

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1 01998Applied Poultly Science, nc THE NFLUENCE OF METHONNE COMMERCAL LAYNG HENS' R. H. HARMS2 and G. B. RUSSELL Department of Dairy and Poultry Sciences, University of Florida, Gainesville, FL Phone: (352) FAX;. (352) H. HARLOW and E J. VEY Novus nternational, Znc., 20 Research Park Drive, St. Charles, MO Primary Audience: Egg Producers, Feed Manufacturers, Researchers DESCRPTON OF PROBLEM The dietary energy level of a feed is usually used as a basis for setting nutrient levels [l]. This approach to formulation of poultry feeds is based on the concept that poultry tend to eat to meet their energy needs, assuming that the diet is adequate in other essential nutrients [2, 3,4,5]. Harms [6] reported that egg production of commercial layers receiving diets containing 720 or 840 kcal of productive energy was equal to the production of hens receiving a diet containing 960 kcal of energy. However, feed intake was increased when diets with lower levels of energy were used. After 4 months, all hens previously fed diets containing 720 or 840 kcal were fed the diet with 960 kcal. The hens immediately adjusted feed intake to be equal to that of those that had received the diet with 960 kcal. Harms [6] concluded that data again confirm that the hen eats to meet her energy requirement and that a sudden change in the energy level in the feed will only result in her making a change in feed intake to compensate for the energy differences. Harms et af. [7l reported that the energy level of the diet does not actually affect the Met requirement of the hen, but does affect the requirement as expressed by a percentage 1 Florida Agricultural Experiment Station Journal Series No. R To whom correspondence should be addressed

2 46 JAPR PROTEN, ENERGY, AND MET FOR HENS of the diet. These workers reported that the requirement for Met matched levels of 0.271, 0.237, and 0.204% with energy levels of 2112, 1848, and 1584 kcal of productive energy kg of diet, respectively. There are factors other than the energy level of the diet that affect energy intake. Emmans [S summarized data from 14 published experiments concerning the effect of temperature on ME energy intake. He suggested ME intakes of 365, 329, 274, and 172 kcal/bird/day for temperatures of -3", 15",29", and 38"C, respectively. Sloan and Harms [9] measured feed intake in two evaporative cooled houses. n Experiment 1, feed intake was 113.8, 103.2, 101.5, and 94.4 glhenlday at temperatures of 27.5", 29.2", 30.8", and 31.8"C, respectively. Marsden and Morris [lo] used a multiple linear regression technique to estimate coefficients for ME intake, heat production, body weight, rate of lay, egg weight, egg output, and egg energy as a function of enviromental temperature. Pesti et ul. ill] used the data compiled by Marsden and Morris [lo] and refined their coefficients. Pesti et al. (111 concluded that their model could serve as a basis for an econometric model of egg production. There is obviously considerable interest in developing a model for predicting performance of the commercial layer. This use of a model is especially appropriate for laying hens because their feed is formulated on the basis of daily feed intake and daily nutrient requirements [12, 13, 141. Therefore, the present study was conducted to determine the performance of hens fed two levels of protein, two levels of energy, and three levels of Met. This study also attempted to determine the Met and energy requirement as affected by composition of diet. This design was used to determine the influence of each on the daily Met and energy intake and the Met and energy consumed per gram of egg content (EC), and not to determine the Met requirement of the hen. MATERALS AND METHODS A total of 480 Hy-Line W-36 [15] hens were placed in individual cages at 20 wk of age and fed diets formulated to meet their daily nutrient requirements [14]. The hens were maintained in a windowless house and given 16 hr of artificial light (0400 to 2000 hr). Temperature was controlled to a minimum of 31.7"C to ensure a constant feed intake. The experiment was conducted in January and February, at 28 wk of age; therefore, the house temperature seldom exceeded 31.TC. This minimum temperature also resulted in a greater range of Met intake. Twelve experimental diets were fed (Table 1). A 2 x 2 x 3 factorial arrangement, including two levels of protein (12.7 and 15%), two levels of energy (2772 and 3080 kcal ME/kg) and three levels of Met (0.25, 0.275, and 0.300%) was implemented. The levels of protein were obtained by varying the levels of corn and soybean meal in the diets. The levels of energy were obtained by varying the level of corn oil and sand. The levels of Met were obtained by the addition of DL-Met when needed. The diets were formulated using determined amino acid values for the corn and soybean meal. Eight replicates of five individually caged hens received each of the 12 diets. Feed and water were consumed ad libitum. Egg weight and shell weight data were collected on 1 egglhedwk, the last egg produced by each hen each week. These eggs were then broken out and the shell with membrane dried and weighed. Feed consumption (FC) was obtained by replicate at bi-weekly intervals at which time new feed replaced the remaining feed. Egg production (EP) was recorded on an individual hen basis; however, analyses were performed on a replicate basis. Egg mass (EM) was calculated by multiplying EP times EW for each replicate. Daily intake of Met and energy were calculated for each replicate. The mg of Met/g of egg content was determined by dividing daily Met intake by daily EC EC=EW - shell weight X % egg production. ntakes of SAA and Cys were not calculated since it has recently been shown [16] that the daily requirement for Cys is only 175 mg/day. Therefore, all diets would have furnished more Cys than required. Daily energy intake was calculated for each replicate. The energy consumed per gram of EC was calculated by dividing daily energy intake by daily EC. The hens were weighed at the beginning and end of the experiment. The data were subjected to the analysis of variance using the General Linear Models (GLM) procedure of SAS [lq. A summary of probabilities

3 HARMS et al. Research Report 47 ENERGY, kcavkg METHONNE, % NGREDEN' Corn Soybean meal, % Limestone Dicalcium * *Contains 185% P *Sup lied per kg of diet: vitamin A, 6600 U; vitamin,e, 11, U; cholecalciferol, 2200 U; menadione dimet&ipynmidinol bisulfite, 2.2 mg; choline C, mg; nboflann, 4.14 mg; pantothenic aad, 13.2 mg; niacin, 39.6 mg; ntamin B14,0.22 mg; ethoxyquin, 125 mg; manganese, 60 mg; iron, 50 mg; copper 6 mg; iodine, 1.1 mg; zinc, 235 mg; selenium, 0.1 mg. appears in Table 2. Significant differences among diets within a level of protein and energy were determined by Duncan's [18] multiple range test. Egg content and mg Met/g EC table were regressed on Met intake. Egg content was also regressed on energy intake and kcal/g EC. RESULTS AND DSCUSSON Egg production was significantly higher (76.74 vs %) for hens receiving the diet contahhg 15% protein as compared to hens receiving the diet with 12.7% protein. Egg production increased (P=.OOOl) as the Met content of the diet increased at each protein and energy level (Table 3). As Table 2 shows, egg production decreased when the energy level of the diet increased (79.25 vs ). The greatest decrease in EP when energy was increased was at the lowest level of Met. The increase in EP from increasing the Met was greater when the level of energy increased. The interaction of Met x energy (Table 2) was significant (P=.OOO4) as a result of a larger increase from increasing Met when the diet contained 3080 kcal of energy, The differences in EP between diets was due to the Met content of the diets and differences in energy which influenced feed intake (Table 4). Feed intake increased as the Met content was increased (P=.OOOl). This increase in feed intake was a result of an increased energy need for the increased EP. Also, the feed intake decreased when the energy content of the diet was increased (P =.OOOl). The finding that Met and energy influences feed intake agrees with a previous report [18]. These data indicate that Met intake determines the amount of egg output produced. The hen consumes enough energy to support this output. None of the interactions was significant. Egg weight increased as the Met content of the diet increased (Table 5). Egg weight decreased when the energy of the diet was increased EW (P =.0428). This finding results from a lower feed intake of hens receiving the high energy diet, a situation which resulted in a lower Met intake. Egg content increased with each increase in Met content of the diet (Table 6). This increase in EC was a result of the increased percentage of Met in the diet and also an

4 48 JAPR PROTEN, ENERGY, AND MET FOR HENS TABLE 2. Summary 7 ANOVA EGG FEED NTAKE EGG WEGHT EGG COhTENT PRODUCTON Protein (P) Energy (E) Methionine (M) PXE PXM EXM PXEXM o.ooo1 o.ooo1 o.ooo O.OOO TABLE 3. Egg production from hens fed diets with different levels of protein, methionine, and energy from 28 to 36 wk of aae PROTEN METHO- ENERGY (kcalkg) NNE PROTEN % METMO- NNE EGG PRODUCTON % TO ' ENERGY (kcawg) FEED NTAKE 90.7sa g/hen/day 80.12a 63.66' Ma 76.72a ib ' 60.16' 'ooled SEM Means without a common superscript within a )rotein and energy level differ significantly (PS.05). 78.7Sa 85.90b 70.7Sb 80.06= 6152' 88.66a 77.11a b b o.ooo o.oo01 o.ooo1 o.ooo1 o.oo TABLE 5. Egg weight from hens fed diets with different levels of protein, methionine, and energy from 28 to 36 wk of ape 1-1 PROTEN METHO- ENERGY (kcal/kg) % EGG WEGHT glhen/day 58.13a 57.7sa S7.07b S6.10b 54.97b 54.19' 58.11a S8.59a 57.63a S6.37b b 55.80' Pooled SEM 1.96 a-c Means without a common superscript within a protein and energy level differ significantly (PS.05). TABLE 6. Egg content from hens fed diets with different levels of protein, methionine, and energy from 28 to 36 wk of age 'ooled SEM c Means without a common superscript within a irotein and energy level differ significantly (P.OS).

5 HARMS et al. Research Report 49 increased feed intake resulting in an increase in Met intake (Table 6). Egg content is more critical for evaluating the nutritional requirement because it includes the effect of both EP and EW. Also, the daily Met intake is more accurate for measuring performance of the hen than the percentage of Met in the diet, including the influence of the percentage of Met in the diet and influence of feed intake. All hens lost weight during the 8-wk experiment. n general, hens receiving the diets containing 0.25% Met lost the most weight (Table 7). The loss in BW may have reduced the amount of Met or energy required. The daily intake of Met was highly correlated (Y=O.l196X ; R2=.96 with daily production of EC (Figure 1). This relationship was expected as an increase of Met supports higher EP and larger EW. The Met required to produce 1 g of EC increased (Figure 2) as the Met intake increased (Y=3.595X ; R2=.89). This increase in Met required to produce 1 g of EC may result from a decrease in utilization of the Met at higher intakes. Another reason would be that the hen was using body stores of Met, resulting in a lower percentage of Met used for egg formation at the lower out- PROTEN MEVHO- NNE Pooled SEM ENERGY (kcal/kg) WEGHT LOSS % e/hen Y 82b llob 141a 181a put of EC. The increase in Met required per gram of EC emphasizes the importance of considering the level of production in experiments when evaluating the requirement of the hen for an amino acid. Harms and Russell [19] found that the lysine requirement of the broiler breeder hen to produce 1 g of EC was increased as the lysine content of the diet increased. The requirement for lysine in i Met hkke lrra/hen/d\ FGURE 1. Egg content produced at different daily intakes of methionine (Y=O.l196X ; R2=.96)

6 50 JNR PROTEN, ENERGY, AND MET FOR HENS FGURE 2. Mg methionine/g of egg content produced at different daily intakes of methionine (Y = 3.595x ; R2 =.as) creased from 17.4 to 19.2 mg/g EC as EC of the broiler breeder increased from 36.4 to 44.0 g. These results suggest that if the hens had produced a greater EC, the requirement would be expected to be higher. n a later paper, Harms and Russell [20] proposed a method to calculate the requirement for the population when maximum production was not obtained in an experiment. They suggested that the determined requirement in an experiment was only for the amount of EC produced in that experiment. Therefore, in addition to the determined requirement in an experiment, a calculation is made by multiplying the requirement for 1 g by the difference in g of EC produced in the present experiment and the amount the population should produce. This amount is added to the requirement found in the present experiment. This adjustment may not be sufficient because the requirement per gram of EC increases with each increase in amino acid intake. A more appropriate adjustment might be to extend the linear line to the hens' maximum level of production. The hens' energy intake increased (Y = 0.235X ; R2 =.96) as her production of EC increased (Figure 3). This finding supports the concept that the hen eats to satisfy energy needs [2, 3, 51. The energy consumed per 1 of EC decreased (Y =0.0052X ; R5 =.601) as the level of energy increased (Figure 4). This result is due to the hens' requirement for maintenance being met at the lowest output of EC. Therefore, as the level of production increases a greater percentage of the energy intake is used for egg formation and less for body maintenance. The ratio of Met to energy per g of EC should be optimal at the highest level of production. But this finding does not agree with a previous statement that amino acid requirements should not be stated as a ratio with energy [M.

7 HARMS et al. Research Report Energy intake (kcallhenid) FGURE 3. Egg content produced at different daily intakes of energy (Y=0.235X ; R2=.96) 6.6 a Energy intake (kcal/hen/d) FGURE 4. Energylg of egg content at different daily intakes of methionine (V=O.O05W ; R2=.601)

8 52 JAPR PROTEN, ENERGY, AND MET FOR HENS CONCLUSONS AND APPLCATONS 1. The Met content of the diet is a major factor that controls the amount of egg content (EC). 2. The Met per g EC increases as the output of EC increases. 3. The hen consumes energy to support the amount of EC supported by Met intake. 4. The energy per g EC decreases as the output of EC increases. 5. The relationship of the amount of energy and Met consumed per g EC should be considered when formulating feed for commercial layers. 6. t may be possible that one feed when formulated on the proper energy:amino acid ratio can meet the amino acid requirement for each pullet from 18 to 40 wk of age. 7. The ratio would change with layer house temperature since this would influence the energy required to produce a g of EC. 1. National Research Council, Nutrient Reuirementsof Poultry.9th RevEdition. Natl. Acad. Press, 8Jashington DC. 2. Hill, F.W. and LM. Dansky, Studies of the protein requirement of chicks and its relation to dietary energy level. Poultry sci HW, F.W. and LM. Dnnsky, Studies on the energy requirement of chickens. 1. The effect of dietay ener level on growth and feed consumption. Poultryscl. 33:1g Hill, F.W., D.L Anderson, and LM. Dansky, Studies on the energy requirement of chickens. 3. The effect of dietary energy level on the rate and gross efficiency of egg production. Poultry Sci Scott, M.L, M.C. Neshiem, and RJ. Young, Nutrition of the Chicken. 3rd Edition. M.L. Scott, thaca, NY. 6. Harms, RH., Sudden feed changes and the laying hen. Feed Age 14(11): Harms, RH., B.L Damron, and P.W. Waldroup, nfluence of energy level upon performance and methionine requirement of the laymg hen. Pages in: Proc. Seventh ntl. Congress of Nutr., Hamburg, Germany. 8. Emmans, G.C., The effect of tem rature on the performance of layin hens. Pages 79-&n: Energy Requirementsof Poult.%.R Mornsand B.M. Freeman, eds. Br. Poultry Sci. Ltx, Edinburgh, UK. 9. Sloan, D.R and RH. Harms, Performance of commercial laying hens at variouslocations in evaporative cooled houses. Appl. Agr. Res. 1: Marsden, A. and T.R. Morrls, Quantitative revlew of the effects of envlronmental temperature on REFERENCES AND NOTES food intake, e out ut, and energy balance in laying pullets. Poultry%. A Pes& G.M., J.H. Darfman, and M.J. Gonzalez-A, Model for redicting egg output and metabolizable energy intake oflaying pullets. Br. Poultry Sci. 33: Harms, RH., CR Douglas, RB. Christmas, B.L. D.mron, and RD. Miles, Feedin commercial layers for maximum production. Feedstuft SO(8):2>tl. 13. Harms, RH., Revised specifications for feeding commercial layers based on daily feed intake. Feedstuffs 51(41): Harms, RH., specifications for feeding commercial layers based on daily feed intake. Feedstuffs 53(47):W Hy-Line nternational, West Des Moines, LA Harms, RH. and G.B. Russell, Evaluation of the cyctine re uirement of the commercial laying hen. J. Appl. Poultry%es SAS nstitute, SAS User s Guide: Statistics SAS nstitute nc., Cary, NC. 18. Duncan, D.B., Multiple range and multiple F tests. Biometrics 11: Harms, RH. and G.B. Russell, A reevaluation of the protein and lysine re uirement for broiler breeder hens. Poultry Sci k. 20. Harms, R.H. and G.B. Russell, Reevaluation of the methionine and protein re uirements of the broiler breeder hen. Poultry Sci