Comparison of the nutrient analysis and caloric density of 30 commercial seed mixtures (in toto and dehulled) with 27 commercial diets for parrots

1. Journal of Animal Physiology and Animal Nutrition ISSN 0931-2439
ORIGINAL ARTICLE
Comparison of the nutrient analysis and caloric density of 30
commercial seed mixtures (in toto and dehulled) with
27 commercial diets for parrots
G. J. D. L. Werquin, K. J. S. De Cock and P. G. C. Ghysels
R&D Department, Versele-Laga N.V., Kapellestraat, Deinze, Belgium
Correspondence Summary
G. Werquin, DVM, R&D Department, Versele-
Laga, Kapellestraat 70, B-9800 Deinze, In this paper, an overview is given of the composition of 30 commer-
Belgium. Tel: +32 9 381 32 00; cially available parrot seed mixtures. As parrots dehull the seeds, the
Fax: +32 9 381 31 70; analysis of the total seed mixture tends to differ from that of the
E-mail: guy.werquin@verla.be ingested feed. Statistical evaluation and comparison of the dehulled
seeds vs. the whole seeds indicates that most parrot species are fed a diet
Received: 15 September 2004;
accepted: 12 November 2004
rich in fat (31.7 ± 13.1% crude fat) and energy (22.4 ± 2.9 MJ ME/kg).
As the analysis of the total seed mixtures underestimates fat and energy
content of the ingested feed, it is suggested that researchers, bird nutri-
tionists and bird food producers should calculate diets based on the ana-
lysis of the dehulled seeds. Finally, the calculated data were compared
with the composition of formulated pelleted/extruded diets on the mar-
ket. These data indicate that the energy density of most diets
(15.6 ± 1.4 MJ ME/kg) is far below the energy density of common seed
mixtures.
seeds, the analysis of the kernels should be taken
Introduction
into account to calculate the composition of the
Although there are some publications concerning really ingested food (Kamphues et al., 1997). A few
nutritional requirements in parrots (Kamphues and authors published data on the proportion of husk
Wolf, 1997; Wolf et al., 1997a), exact scientific data and kernel and the content of nutrients in dehulled
are rather limited until now. Most parrots are fed seeds (Ullrey et al., 1991; Kamphues et al., 1993,
seed mixtures, supplemented with fruits, egg food, 1997b, 1999; Bayer, 1996; Wolf, 2002). However,
vegetables etc. The composition of most commercial for most bird fanciers it remains a difficult task to
seed mixtures is based on practical experience rather calculate the nutrient intake of their birds. Not only
than on scientific information. For bird food com- the calculation is rather difficult, often bird fanciers
posed of whole seeds, in most European countries do not dispose of the ingredient formula of the seed
the producer is not obliged to supply the analysis of mixtures.
the seed mixture. As a consequence most seed mix- In order to get a better view on the composition
tures are commercialized without detailed informa- of parrot feed, the nutrient levels in 30 commercially
tion concerning their nutrient analysis. As parrots available seed mixtures were calculated according to
dehull most seeds, evaluation of the nutrient intake a procedure presented by Kamphues and Wolf
is complex. A significant proportion of the offered (1997a). The nutrient composition of the total seed
seeds is waste (Bayer, 1996). As the nutrient analysis mixtures was compared with that of the kernels. A
of the whole seeds differs from that of the dehulled statistical evaluation was made in order to establish
Journal of Animal Physiology and Animal Nutrition 89 (2005) 215–221 ª 2005 Blackwell Publishing Ltd 215

2. Comparison of the nutrient analysis of parrot diets G. J. D. L. Werquin, K. J. S. De Cock and P. G. C. Ghysels
the impact of the dehusking of the seeds upon the the kernel of seedi (%), fraction seedi ¼ the propor-
nutrient intake. tion of the seedi in the seed mixture (%), fraction
A new tendency in bird feeding is the use of for- kernel seedi ¼ the proportion of kernel in the seedi
mulated diets for parrots. Several nutritional benefits (%).
are linked to this type of feeding: adequate provision The metabolizable energy was calculated according
of vitamins, minerals and trace-elements, no select- to the formula (Schoemaker and Beynen, 2001):
ive feeding, etc. (Wolf et al., 1997b). The nutrient
composition of these diets was initially based on the EnergyðkJ ME=100 gÞ ¼ ½CP Â 18Š þ ½NFE Â 17Š þ ½CF Â 39Š
requirements in other species (e.g. poultry). In this
paper, the nutrient composition of the pelleted/ As the amount of food ingested is determined by
extruded diets is in relation to that of the kernels in the energy density of the food, all listed nutrients
parrot seed mixtures. were compared on weight basis and on energy basis.
Statistical evaluation of the data was carried out as
Materials and methods follows. Comparison of the analysis in toto vs. the
dehulled fraction was caried out by a paired compar-
The nutrient composition of 30 commercial seed ison t-test. Statistical evaluation of the seed mixtures
mixtures for parrots was calculated based on their vs. pelleted/extruded diets was carried out in two
ingredient formula. Calculations were performed steps. First a F-test was performed in order to deter-
with libraÒ (version 4.6/31, Radar Automation, Bel- mine if there was a significant difference in variance
gium), a software program for formulation of animal between the compared data. In case of a significant
feed. In order to perform the calculations, the analy- difference a heteroscedatic student t-test was per-
sis of the kernel and whole seed was added to the
formed in the other case a homoscedatic student
matrix for each individual ingredient used in the t-test. A probability of p £ 0.05 was considered to
seed mixtures. These data were obtained from own be significant.
laboratory analysis and data of kernel composition
published by Kamphues et al. (1993, 1997b, 1999);
Bayer (1996) and Wolf (2002). The percentage of Results
following nutrients was determined for the whole In Table 1 an overview is given of the average nutri-
seed as well as the kernel: crude protein (CP), crude ent composition of the seed mixtures (in toto and
fat (CF), ash, fibre, calcium, phosphorus and sodium.
dehulled), compared with commercial diets.
The content of soluble carbohydrates [nitrogen free When comparing the analysis of the total seed
extract (NFE)] was calculated by subtracting the per mixtures to their dehulled fraction, a major differ-
cent crude protein, crude fat, crude fibre, moisture ence is the higher fat and energy content in the ker-
and ash from 100. The nutrient composition of the nels. The mean energy content of the dehulled
total seed mixture was calculated according to the fraction was 36% (596 kJ ME/100 g) higher than
formula (developed by Kamphues and Wolf, 1997): the energy content of the total seed mixtures. This
X
Nutrientin toto ¼ ðfraction seedi  nutrient seedi Þ higher energy content in the dehulled fraction is
mainly because of the higher fat content (+60% fat;
with: nutrientin toto ¼ the concentration of the nutri- c. 468 kJ ME/100 g). Also the higher protein content
ent in the total seed mixture (%), nutrient seedi ¼ in the dehulled fraction contributes to the higher
the concentration of nutrient in seedi (%), fraction energy content in the dehulled fraction (+42% pro-
seedi ¼ the proportion of the seedi in the seed mix- tein; c. 108 kJ ME/100 g). These data suggest that
ture (%). the protein, fat, and as a consequence energy con-
The nutrient composition of the dehulled seed tent in parrot rations are higher than assumed when
mixture was calculated according to the formula: analysis of the total seed mixtures is regarded. Con-
P
ðfraction seedi  fraction kernel seedi  nutrient kernel seedi Þ
Nutrientkernel ¼ P
ðfraction seedi  fraction kernel seedi Þ
with: nutrientkernel ¼ the concentration of the nutri- sidering this impact of dehusking upon nutrient con-
ent in the dehulled seed mixture (%), nutrient tent could be helpful when developing formulated
kernel seedi ¼ the concentration of the nutrient in diets. Fat and energy content of the commercial
216 Journal of Animal Physiology and Animal Nutrition 89 (2005) 215–221 ª 2005 Blackwell Publishing Ltd

3. G. J. D. L. Werquin, K. J. S. De Cock and P. G. C. Ghysels Comparison of the nutrient analysis of parrot diets
Table 1 Composition of 30 seed mixtures (in toto + dehulled) compared with 27 commercial pellets for parrots (mean ± SD)
Seed mixtures
Nutrient In toto Dehulled Commercial pellets
On weight basis (%)
Crude protein 14.2 ± 1.0 20.2 ± 2.7*** 16.3 ± 2.6
Crude fat 19.7 ± 6.3 31.7 ± 13.1*** 8.6 ± 4.1
Crude fibre 17.1 ± 5.0 3.7 ± 0.8*** 3.7 ± 1.2
Carbohydrates (NFE) 36.3 ± 10.5 37.5 ± 15.7ns 56.9 ± 5.0
Calcium 0.178 ± 0.209 0.181 ± 0.288ns 0.720 ± 0.196
Phosphorus 0.372 ± 0.047 0.628 ± 0.107*** 0.500 ± 0.144
Sodium 0.016 ± 0.005 0.031 ± 0.008*** 0.127 ± 0.057
Calcium/phosphorus 0.47 ± 0.55 0.29 ± 0.50ns 1.51 ± 0.35
Energy (MJ ME/kg) 16.4 ± 1.0 22.4 ± 2.9*** 15.6 ± 1.4
On energy basis (g/MJ ME)
Crude protein 8.7 ± 0.4 9.0 ± 0.6** 10.5 ± 1.9
Crude fibre 10.3 ± 2.7 1.6 ± 0.3*** 2.4 ± 0.7
Calcium 0.111 ± 0.140 0.085 ± 0.149ns 0.463 ± 0.126
Phosphorus 0.226 ± 0.024 0.280 ± 0.020*** 0.313 ± 0.095
Sodium 0.010 ± 0.003 0.014 ± 0.004*** 0.080 ± 0.038
Caloric distribution (%)
Fat 46.2 ± 12.9 53.3 ± 16.3 20.8 ± 8.4
Carbohydrates 38.2 ± 12.9 30.5 ± 16.2 60.3 ± 8.4
Protein 15.6 ± 0.8 16.2 ± 1.1 18.9 ± 3.4
Statistical significance (seed mixtures in toto compared with the dehulled fraction).
ns, not significant (p > 0.05); **p < 0.01; ***p < 0.001.
pellets were significantly lower compared with the seed mixtures with the lowest energy density
dehulled fraction of 30 seed mixtures (p < 0.001). (17.8 MJ ME/Kg). Another important difference
These data may indicate that the average fat between the dehulled seed mixtures and the com-
(8.6 ± 4.1%) and energy (15.6 ± 14 MJ ME/Kg) mercial diets is the caloric distribution (Fig. 2). In
content of the pelleted/extruded diets might be too dehulled seed mixtures, 53.3 ± 16.3% of the metab-
low for optimal parrot feeding. A scatter plot depict- olizable energy originates from fats, only 30.5 ±
ing the energy content in the seed mixtures and 16.2% from carbohydrates. This order is reversed
diets is given in Fig. 1. in the pelleted/extruded diets: carbohydrates apport
Even the formulated diets with the highest energy 60.3 ± 8.4% of the energy, the fats apport only
content (Table 2) still contain less energy than the 20.8 ± 8.4% of the metabolizable energy.
Fig. 1 Scatter plot depicting metabolizable
energy in pellets, dehulled seed mixtures
(kernels) and total seed mixtures.
Journal of Animal Physiology and Animal Nutrition 89 (2005) 215–221 ª 2005 Blackwell Publishing Ltd 217

4. Comparison of the nutrient analysis of parrot diets G. J. D. L. Werquin, K. J. S. De Cock and P. G. C. Ghysels
Table 2 Nutrient analysis (% on weight basis) of 27 formulated pellets for parrots, sorted by energy density
Energy (MJ ME/kg) Protein Fat Fibre Ash NFE Ca P Na
Versele-Laga nutribird P15 original 17.61 15.0 16.0 3.5 4.5 51.0 0.90 0.53 0.16
Versele-Laga nutribird P15 tropical 17.61 15.0 16.0 3.5 4.5 51.0 0.90 0.53 0.16
Versele-Laga nutribird P19 original 17.56 18.8 16.0 4.0 4.5 46.7 0.80 0.54 0.15
Versele-Laga nutribird P15 tropical 17.56 18.8 16.0 4.0 4.5 46.7 0.80 0.54 0.15
Harrison high potency formulas 17.13 18.0 15.0 6.5 3.2 47.3 0.90 0.40 0.08
Pretty bird breeder select 16.81 16.0 10.0 2.0 3.0 59.0 0.81 0.39 0.10
Pretty bird hi-energy 16.79 15.0 11.0 3.0 3.3 57.7 0.69 0.55 0.08
Pretty bird cockatiel 16.54 14.0 10.0 3.5 3.0 59.5 0.22 0.19 0.04
Zupreem avian breeder diets 16.51 20.0 10.0 3.0 NA 53.0 NA NA NA
Pretty bird African select 16.44 16.7 9.5 3.0 3.5 57.3 0.70 0.58 0.07
Hagen tropican lifetime parrot 15.89 14.0 9.0 4.5 4.5 58.0 0.70 0.45 0.06
Pretty bird eclectus 15.88 16.0 6.0 2.0 3.3 62.7 0.70 0.35 0.08
Hagen tropican high performance 15.80 22.0 9.0 3.5 6.5 49.0 1.20 0.90 0.12
Pretty bird daily select 15.52 14.0 5.0 3.0 3.0 65.0 0.70 0.35 0.06
Harrison adult lifetime coarse 15.42 15.0 5.5 4.4 2.9 62.2 0.61 0.40 0.06
Zupreem avian maintenance diets 15.27 14.0 4.0 2.5 3.7 65.8 0.58 0.49 0.14
Pretty bird hi-pro 15.16 17.0 4.0 4.0 3.0 62.0 0.70 0.36 0.09
Kaytee exact original parrot breeder 15.15 18.0 7.0 5.0 6.0 54.0 0.80 0.65 0.20
Kaytee exact rainbow parrot breeder 15.15 18.0 7.0 5.0 6.0 54.0 0.80 0.65 0.20
Kaytee exact rainbow parrot chuncky breeder 15.15 18.0 7.0 5.0 6.0 54.0 0.80 0.65 0.20
Kaytee exact original parrot 14.90 15.0 6.0 5.0 6.0 58.0 0.60 0.50 0.20
Kaytee exact rainbow parrot 14.90 15.0 6.0 5.0 6.0 58.0 0.60 0.50 0.20
Kaytee exact rainbow parrot chuncky 14.90 15.0 6.0 5.0 6.0 58.0 0.60 0.50 0.20
Roudybush daily maintenance 13.01 11.0 7.0 3.5 NA 48.8 0.40 NA NA
Roudybush low-fat maintenance 13.00 12.0 3.0 3.5 NA 56.9 0.40 NA NA
Roudybush high-energy breeder 13.00 19.0 7.0 2.0 NA 40.3 0.90 NA NA
Roudybush breeder 13.00 20.0 3.0 2.0 NA 48.4 0.90 NA NA
Values are given by the feed producer.
NA, data not available.
The protein content of the dehulled seed mixtures mixtures vs. 8.7 ± 0.4 g/MJ ME for total seed mix-
(20.2 ± 2.7%) was significantly higher than that of tures). The commercial diets contained less protein on
the total seed mixtures (14.2 ± 1.0%). As the weight basis (16.3 ± 2.6%), but more on energy basis
dehulled seed mixtures contain also more energy, (10.5 ± 1.9 g/MJ ME), in comparison with the
the differences were much smaller when calculated dehulled seed mixtures. Although only little informa-
on energy basis (9.0 ± 0.6 g/MJ ME for dehulled seed tion is available on protein requirements in parrots,
protein content in the commercial diets seems to
be appropriate (Fig. 3). The protein requirements
for maintenance were estimated between 7.5 and
10 g/MJ ME (compare reviewed data in: Kamphues
et al., 1997a,b; Wolf et al., 1997b; Wolf, 2002).
As the hulls of the seeds are rich in fibre, the
crude fibre content of the dehulled seed mixtures
(3.7 ± 0.8%) was significantly lower than that of the
total seed mixtures (17.1 ± 5.0%). On weight basis,
the crude fibre content of the diets (3.7 ± 1.2%) was
comparable with that of the dehulled seed mixtures.
On energy basis, the fibre content in the diets
(2.4 ± 0.7 g/MJ ME) revealed to be higher than in
the dehulled seed mixtures (1.6 ± 0.3 g/MJ ME;
Fig. 2 Caloric distribution of formulated pellets vs. dehulled seed mix-
tures.
Fig. 4).
218 Journal of Animal Physiology and Animal Nutrition 89 (2005) 215–221 ª 2005 Blackwell Publishing Ltd

5. G. J. D. L. Werquin, K. J. S. De Cock and P. G. C. Ghysels Comparison of the nutrient analysis of parrot diets
Fig. 3 Scatter plot depicting protein content
on energy basis in pellets, dehulled seed mix-
tures (kernels) and total seed mixtures.
Fig. 4 Scatter plot depicting crude fibre con-
tent on energy basis in pellets, dehulled seed
mixtures (kernels) and total seed mixtures.
Fig. 5 Scatter plot depicting calcium/phos-
phorus ration in pellets, dehulled seed mix-
tures (kernels) and total seed mixtures.
Concerning minerals all seed mixtures were char- (0.628 ± 0.107%) than in the total seed mixtures
acterized by a very low calcium content. No statisti- (0.372 ± 0.047%). As a consequence, dehulling
cal differences in calcium content were observed aggravates the improper calcium/phosphorus bal-
between the seed mixtures and their dehulled frac- ance. The mean calcium/phosphorus ratio for
tions (Table 1). The phosphorus levels were signifi- dehulled seed mixtures was very low: 0.29 ± 0.50.
cantly higher in the dehulled seed mixtures Only two seed mixtures, which were supplemented
Journal of Animal Physiology and Animal Nutrition 89 (2005) 215–221 ª 2005 Blackwell Publishing Ltd 219

6. Comparison of the nutrient analysis of parrot diets G. J. D. L. Werquin, K. J. S. De Cock and P. G. C. Ghysels
with oystershells, had calcium/phosphorus ratios >1. Comparison of the energy content of the formula-
As pelleted/extruded diets are formulated, they con- ted diets for parrots, actually available on the mar-
tained higher calcium levels (0.693 ± 0.237%) and ket, with 30 commercial seed mixtures reveals that
better Ca/P ratios (1.51 ± 0.35; Fig. 5). an important difference may be the energy content:
The sodium content of the seed mixtures was very the mean energy content of the seed mixtures
low 0.016 ± 0.005% in the total seed mixtures, (22.4 MJ ME/kg) was 45% higher than in the for-
0.031 ± 0.008%. As expected, the formulated diets mulated diets (15.6 MJ ME/kg). This lower energy
contained higher sodium levels (0.127 ± 0.057%). density is mainly because of the lower fat content.
The sodium requirements for parrots have not been Commercial diets had an average fat content of
studied until now. In poultry, the NRC requirements 8.6%, while the dehulled seed mixtures contain
for sodium are 0.15% (National Research Council, 31.7% fat. In seed mixtures, fats are the main
1994). This sodium level is also recommended for energy source. In the commercial diets, carbohy-
companion bird diets (Brue, 1994). Surprisingly, 12 drates are the main energy source.
of the formulated diets had sodium levels below Further research is needed to determine the opti-
these recommendations. mal energy content in the food for different parrot
species. The seed mixtures with the highest energy
levels, containing more than 50% fat in their de-
Discussion
hulled fraction, are probably not suitable for most
In this study, the nutrient composition of 30 com- parrots in captivity (which have limited physical
mercial seed mixtures for parrots was compared with activity), and can induce obesity when fed ad libi-
their dehulled fraction (portion which is really inges- tum. Obesity is a common problem in captive par-
ted). These calculations demonstrate that parrots rots, and seed mixtures with high levels of oilseeds
which are offered seed mixtures receive a ration should be avoided or fed restrictively.
with a higher fat and energy content. Important is On the contrary, a lot of commercial diets have an
that the analysis of the total seed mixture underesti- extremely low fat content: 17 of them had a fat con-
mates the energy content of their ingested portions tent £7%. These products may be suitable as slim-
with 36%. Therefore, the calculation of the nutrient ming diet for captive parrots that are already obese.
analysis of the dehulled fraction of the seed mixture However, energy and fat levels of it may be insuffi-
gives a better estimation of the real composition of cient for optimal breeding condition.
the parrot diet. Researchers and bird nutritionists With the current available information, it seems
should use these data when evaluating food rations that the diets with the highest fat levels correspond
for parrots. Birdfood manufacturers should be best with the natural feed intake of most parrot spe-
encouraged to provide these data. cies. As palatability of the diets is generally lower
A large variation in energy content was noted than for natural seeds, a high fat content is safer in
between the commercial seed mixtures. Energy den- order to guarantee sufficient energy intake. Techni-
sity in the dehulled seed mixtures varied between cal aspects are probably one of the reason for the
17.76 and 27.25 MJ ME/kg. Because of this vari- relatively low fat content in most formulated diets.
ation in energy level in parrot food, all nutrient lev- Some of them are made with a pellet press. On these
els and nutrient requirements should be expressed pelleting systems, only low fat levels can be
in relation to the energy level instead of on weight obtained. Modern extrusion equipment allows to
basis, as it was recommended by Kamphues et al. produce diets with higher fat levels.
(1993). Another aspect that complicates the application of
Also in parrot nutrition, more and more, empirical fats and oils is their susceptibility to oxidation and
composed seed mixtures are replaced by complete, rancidity. This is certainly the case for the vegetable
formulated diets meeting all nutrient requirements oils rich in unsaturated fatty acids present in the
of the birds. These provide the needed amino acids, natural seed diet of parrots. A wellstudied antioxid-
minerals, trace elements, essential fatty acids and ant system is needed to avoid rancidity. Modern air-
vitamins. Extruded diets have additional advantages tight packaging with modified atmosphere also offers
because of the chemical and physical changes during new perspectives.
the process of extrusion. The high temperatures des- The protein/energy ratio of the diets was in rela-
troy micro-organisms with pathogenic potential and tion to that of the dehulled seed mixtures, indicating
depolymerize starch with an increased digestibility as that the protein intake is similar for diets and seed
a result. mixtures. As most formulated diets are supplemented
220 Journal of Animal Physiology and Animal Nutrition 89 (2005) 215–221 ª 2005 Blackwell Publishing Ltd

7. G. J. D. L. Werquin, K. J. S. De Cock and P. G. C. Ghysels Comparison of the nutrient analysis of parrot diets
with amino acids, the amino acid profile of the for- Kamphues, J.; Wolf, P.; Bayer, G.; Wentker, M., 1997a:
mulated diets should be better than for the seed Basic data on the composition of seeds and feeds used
mixtures. Also the crude fibre content of the diets ¨
in pet bird nutrition. Ubers. Tierernahrg. 25, 205.
¨
was similar to that of the seed mixtures. Kamphues, J.; Wolf, P.; Otte, W., 1997b: Untersuchun-
Concerning the minerals, the seed mixtures gen zu Variationsursachen des Harnsaurespiegels im
¨
showed to be deficient on calcium at the exception Plasma von Graupapageien. Proceedings of the Society of
of two mixtures enriched with oystershells. All for- Nutritional Physiology 6, 159.
mulated diets had acceptable calcium/phosphorus Kamphues, J.; Schneider, D.; Leibetseder, J., 1999:
¨
Supplemente zu Vorlesungen und Ubungen in der Tierernah-¨
ratios (ranging from 1.16 to 2.25). Surprisingly, 12
rung, 9 Aufl. Schaper, Alfeld – Hannover, Germany,
pelleted/extruded diets had sodium levels lower than
pp. 294–301.
the NRC requirements (0.15%).
National Research Council, 1994: Nutrient Requirements of
Poultry, 9th edn. National Academy Press, Washington,
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Journal of Animal Physiology and Animal Nutrition 89 (2005) 215–221 ª 2005 Blackwell Publishing Ltd 221