A preliminary experiment with graded levels of leucine from 0.60 to 1.0% of diet suggested that 0.90% supported maximum weight gain; this observation was repeated in the experiment summa[r]
Trang 1An Estimate of Quantitative Needs1'2
ISHOLA ADAMSON ANDHANS FISHER
Department of Nutrition, Rutgers University, New Brunswick, New Jersey 08903
ABSTRACT The quantitative essential amino acid requirement of the growing
female New Zealand rabbit has been estimated, using weight gain as the response
criterion The diet used was chemically defined, and the amino acid component was
patterned after methionine-supplemented isolated soy protein Each essential amino
acid was fed at graded levels and glutamic acid was varied to provide isonitrogenous
diets The best estimate of the quantitative requirement, as a percentage of the diet,
was found to be: arginine, 1.0; histidine, 0.45; leucine, 0.90; isoleucine, 0.70; lysine, 0.70;
methionine + cystine, 0.60; phenylalanine + tyrosine, 0.60; threonine, 0.50; tryptophan,
0.15 and valine, 0.70 Glycine was required for rapid growth In comparison with other
young, growing mammals, the rabbit has an unusually high arginine requirement that
resembles that of the young chick J Nutr 103: 1306-1310, 1973
INDEXING KEY WORDS amino acid requirement •rabbit nutrition
The 1964 report of the National Research
Council Subcommittee on Rabbit Nutrition
( 1 ) suggested that the rabbit was relatively
insensitive to differences between high and
low quality protein Evidence has since ac
cumulated that indicates the sensitivity of
this mammal to dietary essential amino
acids is very similar to the rat or chick
Rabbits fed urea as a protein supple
ment, or as a partial protein substitute,
grew significantly less than those in which
the protein source was casein, supple
mented with yeast extract (2, 3) The in
ability of the growing rabbit to utilize
poor quality proteins has also been re
ported (4)
Gaman et al (5) developed a purified
diet that permitted adequate growth, main
tenance, pregnancy and lactation of rabbits
of varying ages Adamson and Fisher (6)
used this diet to ascertain the essentiality
of the following amino acids for the
weaned, growing rabbit: arginine, methio
nine, lysine, leucine, isoleucine, tryptophan,
threonine, valine, phenylalanine and histi
dine Glycine was needed for rapid growth
Except for tentative values for arginine,
lysine and methionine (7, 8), quantitative
requirement values for the essential amino
acids were still lacking
The objective of the present study was
to use the chemically defined diet devel oped earlier in this laboratory with the protein needs supplied as amino acids simu lating the composition of methionine-sup plemented isolated soy protein, except that the nonessential amino acids were replaced
by glutamic acid and glycine in a 50:50 ratio
MATERIALS AND METHODS Six-week-old, weaned, female New Zea land rabbits 3 were used in a series of ex periments in which each amino acid under study was fed at various levels for an 8-day period The rabbits were housed individu ally in metal cages situated in a tempera ture-controlled laboratory The cages had wire screen bottoms which allowed feces and urine to pass into a collection grid
The rabbits had little contact with their voided feces although no attempt was made to prevent coprophagy
Received for publication February 20, 1973.
1 Paper of the Journal Series, New Jersey Agricul tural Experiment Station ; supported In part by Bio médicalScience Support Grant PHS RR 7058.
»Taken, In part, from a thesis presented by the senior author to the Graduate School of Rutgers University In partial fulfillment of the requirements for the M.S degree.
»Purchased from Davidson Mill Farms, Somerset,
N J.
Trang 2The diet ingredients were mixed in a
food mixer4 for 15 minutes and were then
pelleted in a laboratory pelleting machine5
without the use of a binder, but with the
addition of 5% cold water
The rabbits were fed the pellets and
water ad libitum The feeding plan was to
fast the animals on the first day following
delivery, followed by giving them the com
plete amino acid diet (for composition see
table 1) for 1 week On the basis of their
weight gain during this period, groups of
five rabbits were assigned, on an equalized
weight basis, to each dietary treatment
which provided a different level of the test
amino acid Four or more levels of the
amino acid under investigation were tested
Each of the 10 essential amino acids re
quired by the rabbit except for glycine was
studied in this manner, in alphabetical
order The amino acid under study was
isonitrogenously replaced with L-glutamic
acid If the growth response to the diet was
not clear, the trial was repeated with a
new choice of amino acid levels The level
of an amino acid estimated as the require
ment was incorporated into the starting
diets of all future studies The requirement
for valine, the last amino acid studied, was,
therefore, estimated with the other nine
essential amino acids present in the propor
tions previously established
RESULTS There was considerable variation within
treatment groups in some of the experi
ments; analysis of variance did not reveal
significant differences at conventional levels
of probability, presumably due to the rela
tively small number of animals used The
best estimate of the requirement for an
amino acid was considered to be the lowest
level that supported essentially maximum
weight gain as in the study of Rao et al
( 10 ) with rats The results are, therefore,
presented in table 2 as means with stan
dard errors
Arginine In a preliminary study in which
four levels of arginine were fed (0.75, 1.00,
1.25 and 2.00%), a concentration of 1.0%
supported maximum weight gain A high
tolerance for arginine was indicated, since
there was no adverse effect from 2% argi
nine In another experiment, summarized
in table 2, two lower levels (0.0 and 0.50% )
TABLE l
Composition of diet
Ingredient
L-Arginine-HCl1 L-Histidine-HCl-HîO1 L-Isoleucine
L-Leucine L-Lysine-HCl1 L-Methionine L-Phenylalanine L-Threonine L-Tryptophan L-Valine L-Glutamic acid Glycine Fiber8 Corn oil Mineral mixture*
Vitamin mixture4 Antioxidant' Dextrin Glucose monohydrate Choline chloride Corns tarch
1.83 0.74 1.04 1.20 1.79 0.36 0.80 0.62 0.16 0.88 4.21 4.29 16.0 5.0 6.6 0.2 0.025 5.0 26.0 0.1
to 100
1Appropriate correction was made to supply the desired level of the free amino acid J Solka Floe, Brown Co., Berlin,
N H «Composition: (mg/kg) CoCli-6HiO, 3.5; KI, 10; CuSOi-SHiO, 34.6; MnSOi-HjO, 81.1; ZnSO., 169;
Fe(HOCH,-(CHOH).COi), 706.3; (NH,),Mo7Oi.-4H,O, 22.7;
(g/kg) KiHPO., 10; KHCOi, 8; NaCl, 5; CaCOi, 12.5;
CaHPOi, 10; MgSU4, 10 «Composition; (mg/kg) thiamin • HC1, 25 ; riboflavin, 16; Ca pantothenat«, 20 ; py ridoxine • HO,
6 ; biotin, 0.6 ; folie acid, 4 ; menadione sodium bisulfite complex,
as retinyl acetate, 10,000 IU; vitamin DI, 600 IU;a-tooopheryl acetate, 60 IU These vitamins were kindly supplied by Merck, Sharp and Dohme, Rahway, N J and Hoffman-LaRoche, Nutley, N J ' Santoquin, kindly supplied by Monsanto Co.,
St Louis, Mo.
were tested, along with those used in the preliminary study except that the 2.0%
level was omitted The significant treat ment difference for weight gain ( P < 0.05 ) was, however, all accounted for by the diet devoid of arginine The level of 1.0% ar ginine supported maximum weight gain
Food consumption was similar for all groups except for the diet devoid of argi nine, in which case it was significantly depressed
ference among treatment levels ( P < 0.05 ) ; the concentration of 0.45% histidine sup ported maximum weight gain Food con sumption was similar for all groups
gain with increasing levels of isoleucine in the diet and the maximum weight gain was observed at 0.70%
4 Hobart Manufacturing Co., Troy, Ohio.
» California Pellet Mill Co., San Francisco, Calif.
Trang 3TABLE 2
Weight gain and food consumption of growing female rabbits receiving different amounts of each of
the essential amino acids
Amino acid%
of
diet00.500.751.001.250.150.300.450.600.750.40
0.50
0.60
0.700.800.400.700.800.90
1.000.600.700.800.901.00Weight
gaing/rabbit/dayArginine13±6"-z15±4b16±3b20±3r13
±6»Histidine320
±4-15±4b27 ±6'21±1"22 ±3'Isoleucine16±5»
24±5'c 30±8b<!
32±5b«22 ±5»Leucine9±2«20±5b°15±3"26±5bc
25±1»Lysine'17
±2-19±7«19 ±4"9
±2"11 ±2"Food
intakeg/rabbit/day61±1070±
875±
765±
668±
956±
653±
960±
858±
358±
358±
8 67±6 72±6 71±
564±
856±
173±
364±
277±
3 70±369
±
769±1169±
466±
466±
6Amino
acid%
of diet0.000.300.600.900.450.550.600.650.300.400.50
0.60 0.70 0.800.000.050.100.150200.250.400.500.600.700.800.90Weight
gaing/rabbit/davPhenylalanine-6
±2«5±5b25 ±3"13 ±2»Methionine'24 ±5«29±5'b35±5r30±3bcThree
nine19 ±3«23±6-24 ±3«
22±3«
19±3*
19±3«Tryptophan-10±2«0±2b15±3°16±2C15±4"16±3"Valine23±4b«16±3"26±2b30±4b25±5bo28±7bcFood
intake0/rabbit/dav28'Wm-<74«80»73«82588155±
463±
661±
2 61±4 50±3 53±
934±
438±
465±
565±
555±
555±
566±
564±
869±
174±
469±
474±
6 1L-Arginine -HC1 was used to supply arginine at the indicated levels 2 Mean ±SEMfor five rabbits; starting weight approxi
mately 1 kg; values that do not share a common superscript letter are significantly different at P < 0.05 • L-Histidine-HCÕ-HiO
was used to supply histidine at the indicated levels *L-Lysine -HC1 was used to supply lysine at the indicated levels : Food
intake was recorded only on a group basis because scattered food fell into a common tray ; this was remedied for the other experi
ments by providing separate wire grids for each cage • Experimental period was 10 days; for all other amino acids it was 8 days.
Leucine A preliminary experiment with
graded levels of leucine from 0.60 to 1.0%
of diet suggested that 0.90% supported
maximum weight gain; this observation was
repeated in the experiment summarized in
table 2 Food consumption was similar for
all groups except the one fed the lowest
level, which had depressed food intake
Lysine The second of two experiments
is reported in table 2 In both experiments,
a level of 0.70% supported maximum
weight gain but unlike in the first experi
ment, in the second, the levels of 0.90 and
1.0% significantly depressed weight gain
although food consumption was similar for all groups
ported maximum weight gain while 0.90%
resulted in a decline The diet devoid of phenylalanine caused a sharp weight loss
The level of 0.60% also satisfied the need for tyrosine Food consumption was highest
at the optimum level for weight gain and lowest for the diet devoid of the amino acid
Methionine In a preliminary experiment,
the highest level fed (0.55%) supported maximum weight gain and satisfied also the
Trang 4TABLE 3
Amino acid requirement pattern for growth of various species based
on threonine taken as unity
ArginineHistidineIsoleucineLeucineMethionine
+
cystinePhenylalanine
+ tyrosineThreonineTryptophanValineLysine—
i—
i0.821.440.790.791.000.120.971.74<0.440.401.111.331.111.111.000.291.111.56i0.411.081.350.961.411.000.221.101.761.540.460.921.851.081.461.000.231.261.462.000.901.401.801.201.201.000.301.401.40
1Calculated from the data presented by Munro (12) - Calculated from the data in Nutrient Requirements of Swine (11)
1Calculated from the data of Rao et al (IO) <Calculated from the data of Baker et al (9) ' Present study • Not required
need for cystine The results of a second
experiment are summarized in table 2
Here a level of 0.60% supported maximum
weight gain and satisfied also the cystine
requirement Food consumption was similar
for all groups ,
Threonine A level of 0.50% supported
maximum weight gain while the two higher
levels of this amino acid (0.70 and 0.80%)
reduced the weight gain Food consump
tion was similar for all groups
essentially maximum weight gain Rabbits
on the diet devoid of this amino acid lost
weight Food consumption was similar for
all groups except for the diet totally devoid
of the amino acid
Valine A level of 0.70% supported maxi
mum weight gain, and food consumption
was similar among all groups The per
formance of the rabbits in this experiment
was among the best in this entire series In
this last experiment the levels of all essen
tial amino acids corresponded to the pre
viously determined requirements
DISCUSSION Some of the results obtained with inade
quate or excessive amounts of individual
amino acids suggested possible imbalances
or toxicity, but no attempt was made to
follow up on these conditions In this con
nection it should be noted, however, that it
was previously observed that the egg pro
tein pattern supported poor growth of rab
bits in comparison with the
methionine-supplemented soy protein pattern, possibly
because of excess amino acids relative to
the requirement ( 6 )
The diet supplying the estimated require ment levels of all the essential amino acids supported better weight gains than the starting diet which contained the methio-nine-supplemented simulated soy protein pattern (30 vs 20 g gain/day) This rate
of gain also compares well with that ob tained on an intact, methionine-supple-mented soy protein diet (31 vs 29 g gain/
day for the soy protein and amino acid diets, respectively )
In general, the amino acid requirements
of the growing rabbit resemble those of the chick ( 9 ) more than those of the rat ( 10 ), the pig (11) or the child (12) (table 3)
Particularly striking is the high arginine re quirement of the rabbit, a species that, un like the chicken, should be readily able to synthesize adequate amounts of this amino acid by virtue of an active urea cycle
1 National Academy of Sciences-National Re search Council ( 1966) Nutrient Require ments of Rabbits Pubi no 1194, Washington,
D C.
2 Olcese, O & Pearson, P B (1948) Value
of urea in the diet of rabbits Proc Soc Exp.
Biol Med 69, 377-379.
3 King, J O L (1971) Urea as a protein supplement for growing rabbits Brit Vet J.
127 523—528
4 Cheeke, P R & Amberg, J W (1972) Protein nutrition of the rabbit Nutr Rept Int.
5, 259-266.
5 Gaman, E., Fisher, H & Feigenbaum, A S.
( 1970) An adequate purified diet for rabbits
of all ages Nutr Rep Int 1, 35-48.
6 Adamson, I & Fisher, H (1971) The amino acid requirements of the growing rab bit: Qualitative needs Nutr Rep Int 4, 59-64.
7 Gaman, E & Fisher, H (1970) The
Trang 5sentiality of arginine, lysine and methionine
for the growing rabbit Nutr Rep Int 1,
57-64.
8 Cheeke, P R ( 1970) Arginine, lysine and
methionine needs of the growing rabbit Nutr.
Rep Int 3, 123-128.
9 Baker, D H., Sugahara, M & Scott, H M.
( 1968 ) The glycine-serine interrelationship
in chick nutrition Poultry Sci 47, 1376-1377.
10 Rao, P B R., Metta, V C & Johnson, B C.
( 1959 ) The amino acid composition and the
nutritive value of proteins I Essential amino
acid requirements of the growing rat J Nutr.
69, 387-391.
11 National Academy of Sciences-National Re search Council (1968) Nutrient Require ment of Swine Pubi 1192, no 2, ed 6, Washington, D C.
12 Munro, H N (1972) Basic concepts in the use of amino acids and protein hydroly-sates for parenteral nutrition American Medi cal Association Symposium on Total Parenteral Nutrition, Nashville, Tennessee, January 17,
1972, p 7.