BIBLIOGRAPHY FORTES, MADELINE D. APRIL...
BIBLIOGRAPHY
FORTES, MADELINE D. APRIL 2013. Preference and Acceptability of Chayote
(Sechium edule Jacq. Swartz) Fruits and Leaves by Rabbits. Benguet State University. La
Trinidad, Benguet.
Adviser: Dr. Sonwright B. Maddul, PhD.
ABSTRACT
This study aimed to determine the palatability and acceptability of fresh chayote fruits
and leaves as feed for rabbits. A total of five New Zealand White rabbits were distributed
using the completely randomized design to the following treatments: T1 = chayote young
leaves, T2 =chayote mature leaves and T3 = chayote fruits. The mean dry matter content
of the test diets were 10.05, 12.85, and 6.36%, respectively. Among the three diets offered,
young leaves were preferred most by the experimental rabbits. Acceptability of the test
diets did not differ and was observed to be quite low.
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
INTRODUCTION
The domestic rabbit (Oryctolagus cuniculus) is a herbivore that feed by grazing on
grass, forbs, and leafy weeds. Consequently, the diet contains large amounts of cellulose,
which is hard to digest. This problem is solved by autocoprophagy in which rabbits reingest
their own soft feces (Hirakawa, 2001) rather than chewing the cud as do other herbivores
to digest their food further and extract sufficient nutrients. Feeding an appropriate diet to a
rabbit is probably the single most important factor in maintaining its health.
Due to high cost of feeds, rabbit raisers keep on trying different alternative feeds
and supplement to meet the requirement for excellent upkeep of rabbit. This situation is
also made worse during dry season when green feeds are scarce. The challenge is to make
use of feed material that could be available locally. The feeding of alternative forage to
rabbits, especially in the dry season, is essential when grass and herbaceous forages are
scarce. Sechium edule or chayote remains green most of the year and provides nutrients,
being rich in amino acids, vitamins and minerals that are most often lacking in the dry
season. However, there needs to further investigate the use of this plant because of its
relative availability as alternative feed resource to rabbits (http://www.botanical-
online.com/english/chayoteproperties.htm). Aung et al. (1990) mentioned that in addition
to its fruits, chayote yields tender shoots for use as vegetable greens, vines as ornament for
fences or as animal fodder, and edible subterranean storage roots.
However, acceptability of feeds by rabbits is a predicament in feeding and nutrition
research. Pond et a.l (2005) mentioned that in essence, palatability is the result of a
summation of many different factors sensed by the animal in the process of locating and
consuming food. Palatability is determined by the appearance, odor, taste, texture,
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
temperature and other sensory properties of the food. These properties are, in turn, affected
by the physical and chemical nature of the feed.
The palatability of forages is an important factor in rabbit production, particularly
when the forages are expected to provide a major part of the daily nutrient intake. In
research, palatability usually is measured by giving animals a choice of two or more feeds
so that they can express more preference. Freshness is important to the rabbit, because this
affects the palatability of the feed.
Specifically, the study aimed to:
1. determine the palatability of chayote as feed for rabbits, and
2. determine the acceptability of chayote by rabbits.
The palatability and acceptability tests were carried out from July to August, 2012
at Upper Tomay, La Trinidad, Benguet.
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
REVIEW OF LITERATURE
In selecting herbage for rabbits, the most important factors for consideration are:
availability of the browse, the crude protein level, the digestibility factors and toxic
constituents. However, the majority of previous studies are on browse plants such as
grasses and legumes, and no literature on the use of chayote as animal feed was available
to the researcher. Hence, only general information on chayote was reviewed.
Grass, both fresh and dried, is an important food for the domestic rabbit, although it
varies very considerably. During the spring the grass grows rapidly, and at this period the
plant is leafy and is rich in protein and low in fibre content. During summer when the plant
flowers, there is a great increase in fibre and a reduction in protein and other digestible
nutrients. The grass improves slightly in autumn, and then tails off again during winter.
Titus young quickly growing grass is an excellent food for all classes of stock, although
older grass is not so valuable, and rank old growth is not at all satisfactory, these variations
are important, for young rabbits may easily starve if fed on old growth (Cheeke, 1987).
The relative palatability of forages fed to rabbits was studied by Osakwe and Ekwe
(2001). Significantly differences (P<0.01) in relative palatability index (RPI) were detected
among the different forages offered. Based on their RPI, rabbits preferred in descending
order of magnitude Centrosema pubescens, Calopoganimar muconoides and Elacis
guincensi (RPI> 95%) to Musa sapientum (RPI>70%) and Andropon gayanas (RPI>40%).
The preferences of oil polar leaves to banana leaves according to RPI are an interesting
observation from the study.
The chayote is used mainly for human consumption. The fruit, stems and young
leaves as well as the tuberized portions of the roots are eaten as a vegetable, both alone and
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
plain boiled, and as an ingredient of numerous stews. Because of its softness, the fruit has
been used for children's food and drinks like juices, sauces and pasta dishes. In Mexico, an
attempt has been made to increase the life of the fruit by drying it. The results have been
positive and have enabled jams and other sweets to be prepared while also producing dried
fruit which can be used as a vegetable after a certain time. Because of their flexibility and
strength, the stems have been used in the craft manufacture of baskets and hats. In India,
the fruit and roots are not only used as human food but also as fodder (Bermejo and León,
1994).
The chayote root is not much utilized for food by the Cordillerans, unlike Mexico’s
indigenous Mayans who also eat the starchy roots – like the fruits and tops – and added it
to beans. Chayote was also the staple food of the indigenous Aztecs in Mexico. At present,
chayote can be prepared and eaten raw as salad. It may be stuffed and baked and may be
prepared mashed, fried or boiled. It can also be used as soup or cream. Unknown to many;
however, the chayote is also a medicinal plant. Its leaves can be made into tea. It can
dissolve kidney stones. On the other hand, it is also used to treat hypertension and
arteriosclerosis, according to an article on chayote history and lore on the Internet (Allad-
iw, 2005).
Samples of Sechium edule, also known as vegetable pear or mirliton, were analyzed
for moisture and dry matter. Dry matter was further analyzed for crude protein, ether-
extractable material, pectin, crude fiber, ash, selected minerals, and nitrogen-free extract.
Fresh mirlitons contain 94% moisture. Carotene was not detected. The mirliton does not
contain detectable amounts of lipoxygenase or polyphenol oxidase activity (compared to
activity in mushroom). Amino acid concentrations in the seed were approximately twice
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
those of the flesh. Methionine was detected in the seed but not in the tissue. The data
suggest that the mirliton can be a new fresh vegetable crop for the southern area and for
processing into frozen food products (Flick et al., 1977).
Presently, only one study was reported to see the effect of feeding fiber from
chayote on biological utilization of diet in the rat (Modgil and Modgil, 2004). Chayote had
better biological value then the bottle gourd. Increase in fiber even from vegetable sources
resulted in the decreased PER, DMD, BV, TPD, NPU, PRE and NPR in rats.
The edible parts of S. edule (fruit, seed, stem and root) are relatively low in fibre,
protein and vitamins compared with other vegetables. Nevertheless, they have a high
caloric and carbohydrate content, especially in young stems, root and seed, and the micro
and macronutrient content of the fruit is adequate. The fruits, and the seed especially, are
rich in several important amino acids such as aspartic acid, glutamic acid, alanine, arginine,
cistein, phenylalanine, glycine, histidine, isoleucine, leucine, methionine (only in the fruit),
proline, serine, tyrosine, threonine and valine (Flores, 1989 as cited by Lira, 1996).
A liquid chromatography−mass spectrometry (LC-MS)-based method was
developed by Siciliano et al., (2004) for the characterization of flavonoids from edible parts
of Sechium edule (Jacq) Swartz. Eight flavonoids, including three C-glycosyl and five O-
glycosyl flavones, were detected, characterized by nuclear magnetic resonance
spectroscopic data, and quantified in roots, leaves, stems, and fruits of the plant by LC-
photodiode array-MS. The glycine moieties are represented by pigenin and luteolin, while
the sugar units are glucose, apiose, and rhamnose. The results indicated that the highest
total amount of flavonoids was in the leaves (35.0 mg/10 g of dried part), followed by roots
(30.5 mg/10 g), and finally by stems (19.3 mg/10 g).
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
MATERIALS AND METHODS
A. Dietary Palatability Test
Experimental animals. A total of five mature rabbits (3 months old) were used in
the study. The rabbits were of the same age, weight and breed (New Zealand White) and
were purchased from a single source to minimize variations. The animals were treated
against endo-and ecto-parasites following recommended practices. The rabbits were
housed individually in elevated cages made of metal framework and wire screen.
Preparation of test diets. Fresh chayote fruit and leaves with petiole and tendrils
were collected within 24 hours. The unpeeled fruits were chopped into four equal parts,
while the leaves were offered upon after collecting. The fruit and leaves served as dietary
treatments:
T1 = Chayote young leaves including petioles and tendrils
T2 = Chayote mature leaves including petioles
T3 = Chayote mature fruit (unpeeled)
Experimental procedure. The experimental animals were given a choice from
several diets or feedstuffs. The relative intakes of the diets were measured quantitatively
to represent the response of the animals. The cafeteria-style was used in which rabbits are
given a selection of different food items presented in equal amounts simultaneously.
The preference trial lasted for 10 days in two phases: protocol conditioning and
preference testing. A 5-day conditioning phase was necessary for familiarizing animals
with each test diet. Following the protocol conditioning phase, a preference trial was
conducted over 5 days. Data on the amount of feed offered and left-overs were gathered
during the last phase.
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
Each feedstuff was weighed and offered simultaneously in separate containers.
Rabbits were offered an initial amount of 1 kg of the test diets twice daily at 6:30 am and
5:00 am. This amount was adjusted based on actual intake during the conditioning phase.
Sufficient feed was placed in each container so that feed would not be depleted and force
the rabbits to eat other feeds. Any feed remaining from the previous feeding was weighed
to determine amount consumed before the containers are refilled. The location of the
containers in the cages was randomized at each feeding to prevent bias due to position.
Drinking water was supplied ad libitum in earthen containers or crocks.
B. Dietary Acceptability Test
The dietary acceptance trial made use of the single choice selection in which
experimental animals were not given a choice of diets. Only one test diet was offered to
the experimental rabbits at a time for a period of 30 minutes. The same dietary treatments
were tested in this trial to involve the same experimental animals used in the palatability
trial.
Each rabbit was offered an amount of 1 kg of T1 (Chayote young leaves including
petioles and tendrils) at 6:30am for two days. The diet was withdrawn from the animals 30
minutes after this was offered and weighed for leftovers. At this time, the animals were fed
with a basal diet of Galinsoga forage for the rest of the day. Another test diet (T2 = Chayote
mature leaves including petioles) was offered in same amount and period of time over two
days. The last test diet, (T3 = Chayote fruits), was offered in same amount and period for
the last two days of the experiment.
Samples of the test diets were dried at 60 °C for 24 hours in a Memmert convection
oven for dry matter determination.
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
Data Gathered
The following data were gathered from both experiments:
1. Amount of feed offered daily(g).The amount of each test diet given to an
experimental animal was measured daily using a feed scale.
2. Amount of feed leftover (g). The amount of feed not consumed by each
experimental animal was also weighed before a new feed was given in the morning.
3. Weight of feed samples before and after drying (g). The weights before and
after oven-drying were used to compute for dry matter content.
Data Computed
From the data gathered, the following indicators were computed:
1. Amount of dry matter in feed (g). The amount of dry matter in the test diet
was computed as:% DM = Weight of Feed Samples after Drying X 100
Weight of Feed Samples before Drying
2. Total feed intake, fresh basis (g). This was obtained by getting the
difference between the amount of feed refused and feed offered to each experimental
animal.
3. Total feed intake, dry matter basis (g). This was computed by multiplying
the total feed intake, fresh basis, of each animal with the DM content of the test diet it
consumed.
4. Relative palatability index. This was calculated as:
Relative Palatability Index: Daily Feed Intake X 100
Highest feed intake
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
5. Relative acceptability index. This was calculated using the formula:
Acceptability Index = Amount of Feed Consumed X 100
Amount of Feed Offered
Data Analysis
All data were subjected to one-way analysis of variance for Completely
Randomized Design of an experiment. In case of significant differences, treatment means
were compared using the Duncan’s Multiple-Range Test.
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
RESULTS AND DISCUSSION
Dry Matter Content of Chayote
Table 1 shows the dry matter content of the experimental diets. Statistical analysis
revealed that dry matter content is significantly different among the parts of chayote used
in the experiment. As expected, the fruit has the lowest dry matter content at 6.36% only.
Flick et al. (1977) reported that fresh chayote fruits contain 94% moisture or 6% dry matter.
Chayote young leaves including petioles and tendrils contained 10.05% dry matter. The
mature leaves including petioles had the highest dry matter content (12.85%). These figures
are within the values reported by Nguyen Van and Nguyen Thi (2008) for water spinach
(9.63%) and sweet potato vine (8.56%).
Preference of Test Diets by Rabbits
Data on feed intake of the experimental animals are presented in table 2. Both daily
and total feed intakes are significantly different among dietary treatments. Young leaves
of chayote were ingested by the rabbits with the greatest amounts both in total and daily
intakes (824.64 g and 164.93 g, respectively). This implies that among the three diets
offered young leaves were preferred by the experimental rabbits.
Table 1. Dry matter content of the test diets
TREATMENTS MEAN ____________
Chayote young leaves
10.05b
Chayote mature leaves
12.85a
Chayote fruits
6.36c
**Means with the same letter superscript are significantly different (P<0.05) by DMRT.
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
Table 2. Mean feed of the test diets by rabbits during the palatability trial
TREATMENTS
TOTAL DAILY
FRESH BASIS (g) _ FRESH BASIS (g)
Chayote young leaves 824.64a 164.93a
Chayote mature leaves
717.04b 143.41b
Chayote fruit 745.08b 149.02b
Means with the same letter superscript are not significantly different (P<0.05) by
DMRT.
Total intakes of fruits and mature leaves are similar at 745.08 and 717.04g, respectively.
Similarly, daily intakes of fruits and mature leaves are not significantly different (149.02
and 143.41 g, respectively). According to Baumont et al. (2000), for a given plant,
ingestibility is dependent on the vegetation stage and the number of the vegetation cycle.
During the first vegetation cycle, ingestibility decreases with the age of the plant. Ball et
al. (2001) further explained that maturity at harvest also influences forage consumption by
animals. As plants mature and become more fibrous, forage intake drops. This preference
for high quality forage has been suggested for rabbits by Kuijper et al. (2004) and Rödel
(2005) as cited by Somers et al. (2008).
Relative Palatability Index
Table 3 shows the relative palatability and preference ranking of chayote diets by
rabbits. Statistical analysis showed no significant differences among treatments. Based on
numerical value, rabbits preferred in descending order of magnitude chayote young leaves
(96.56 %), mature leaves (92.66 %), and fruits (86.94%). The exact reasons for the
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
Table 3. Relative palatability index and preference ranking of the test diets
TREATMENTS RELATIVE PALATABILITY PREFERENCE
INDEX, %ns RANKING
Chayote young leaves 96.56
1st
Chayote mature leaves 92.66
2nd
Chayote fruit
86.94
3rd
Means with the same letter superscript are not significantly different (P<0.05) by DMRT
differences in relative palatability of rabbits fed different forages is not known, and could
not be explained by this study. This is because palatability is a complex phenomenon
determined by dietary type and environmental variables (Molyneux and Ralph, 1992 as
cited by Osakwe and Ekwe, 2007).
Acceptability of Test Diets by Rabbits
Table 4 presents the data on feed intake of the experimental diets in daily and total
basis. Chayote mature leaves had a mean daily acceptance of 96.23 g within a 30-minute
period, followed by chayote fruit at 89.04 g. Young leaves were consumed at a mean of
61.73 g per day. However, treatment differences were found to be non-significant (P<0.05).
Thus, the part of chayote as feed had no effect on acceptability by rabbits. Data show that
experimental rabbits had the same acceptability of the different parts of chayote. The mean
daily feed intake of the fresh test diets by rabbits is 82.33 g
Acceptability Index
The effect of chayote part on relative acceptability index within the allowed
foraging time is shown in table 5. Analysis of variance revealed no significant differences
among the treatment means. It was observed, however, that test diets had low acceptability
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
(6.17 - 9.62%) by rabbits within a period of 30 minutes only. This can be due to the very
short duration at which the diets were made available to the test animals.
Table 4. Mean feed intake of the test diets by rabbits during the acceptability trial
TREATMENTS
TOTAL DAILY
FRESH BASIS (g) FRESH BASIS (g) __
Chayote young leaves
370.40 61.73
Chayote mature leaves
577.40
96.23
Chayote fruit 534.20
89.04
Means with the same letter superscript are not significantly different (P<0.05) by DMRT.
Table 5. Relative acceptability index and ranking
TREATMENTS ACCEPTABILITY ACCEPTABILITY
INDEX, % RANKING
Chayote young leaves
6.17 3rd
Chayote mature leaves
9.62
1st
Chayote fruit
8.89
2nd
Means with the same letter superscript are not significantly different (P<0.05) by
DMRT.
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS
Summary
The tests on preference and acceptability of chayote fruits and leaves by domestic
rabbits were carried out from July to August, 2012 at Upper Tomay, La Trinidad, Benguet.
Fresh chayote fruits and leaves with petiole and tendrils were collected within 24 hours.
The unpeeled fruits were chopped into four equal parts, while the leaves were offered upon
after collecting. The fruits and leaves served as dietary treatments: T1 = Chayote young
leaves including petioles and tendrils; T2 = Chayote mature leaves including petioles; and
T3 = Chayote mature fruit (unpeeled).
A total of five mature rabbits (3 months old) of the New Zealand White breed were
used in the palatability trial which lasted for 10 days and in acceptability trials carried out
in two days for each part of chayote. In the palatability trial, the cafeteria-style was used in
which rabbits were given a selection of the diets presented in equal amounts
simultaneously. Rabbits were offered 1 kg of the test diets in separate containers twice
daily at 6:30 AM and 6:00 PM. The location of the containers in the cages was randomized
at each feeding to prevent bias due to position.
The same dietary treatments were tested in the acceptability trial involving the same
rabbits used in the palatability trial. Only one test diet was offered to the experimental
rabbits at a time for a period of 30 minutes. Each rabbit was offered an amount of 1 kg of
T1 (Chayote young leaves including petioles and tendrils) at 6:30am for two days. The diet
was withdrawn from the animals 30 minutes after this was offered and weighed for
leftovers. At this time, the animals were fed with a basal diet of Galinsoga forage for the
rest of the day. Another test diet (T2 = Chayote mature leaves including petioles) was
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
offered in same amount and period of time over two days. The last test diet, (T3 = Chayote
fruits), was offered in same amount and period for the last two days of the experiment.
Samples of the test diets were dried at 60 °C for 24 hours in a Memmert convection oven
for dry matter determination.
Among the parts of chayote used as test diets, young leaves were preferred most by
the experimental rabbits. However, chayote fruits and leaves have low acceptability by
rabbits.
Conclusions
Relative palatability was affected by the part of chayote as test diet. Young leaves
were preferred most by rabbits. Chayote fruits and leaves had no apparent effect on
acceptance by rabbits. Thus, the fruits, mature and young leaves including petioles and
tendrils can be fed to rabbits.
Recommendations
Fresh chayote fruits, unpeeled and quartered, and the leaves whether mature or
young, including petioles and tendrils, are recommended as alternative feed for rabbits.
These local resources are especially beneficial during shortage of feed supply. Moreover,
this finding has to be confirmed in a feeding trial involving growing and fattening rabbits.
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
LITERATURE CITED
ALLAD-IW, A.L. 2005. Sayote:Hanging Green Gold.Posted by BulatlatVol. V, No. 42.
Retrieved on April 2012 from http://www.bulatlat.com/news/5-42/5-42-
sayote.htm.
AUNG, L. H., A. BALL and M. KUSHAD. 1990. Developmental and Nutritional Aspects
of Chayote (Sechium edule, Cucurbitaceae). Economic Botany. 44(2): 157-164.
BERMEJO, H. and J. LEON.1994. Plant production and Protection. Rome, Italy. P.79-
84
CHEEKE, P. R. 1987.Rabbit Feeding and Nutrition.Orlando; Academic Press. Retrieved
on April 2012 from http://www.mybunny.org/info/rabbit_nutrition.htm.
FLICK JR., G.J., L.H. AUNG, ,R.L. ORY, and A. J. ST. ANGELO. 1977. Nutrient
Composition and Selected Enzyme Activities in SechiumEdule, TheMirliton.J.
Food Science 42(1):11–13.
HIRAKAWA, H. 2001. Coprophagy in leporids and other mammalian herbivores.
Mammal Rev. 31 (1): 61–80. Retrieved on May 10, 2012 from
http://cse.ffpri.affrc.go.jp/hiroh/publications/coprophagyReview.pdf.
LIRA R. S. 1996. Chayote. Sechium edule (Jacq.)Sw. Promoting the Conservation and Use
of Underutilized and Neglected Crops. 8. Institute of Plant Genetics and Crop Plant
Research, Gatersleben/International Plant Genetic Resources Institute, Rome, Italy.
MODGIL, R and M. MODGIL. 2004. Effect of Feeding Chayote (Sechium edule) and
Bottle Gourd (Lageneria siceraria) as Source of Fiber on Biological Utilization of
Diet in Rats. J. Hum. Ecol. 15(2): 109-111.
MOLYNEUX, R. J. and M. N. RALPH, M. N. 1992.Plant toxins and palatability to
herbivores. J. Range Management 45: 1 – 18.
NGUYEN VAN THU and NGUYEN THI KIM DONG. 2008. Effect of Water Spinach
and Sweet Potato Vine Associated With Two Other Natural Plants on Growth
Performance, Carcass Values and Economic Return of Growing Crossbred Rabbits
in the Mekong Delta of Vietnam. Proc. 9th World Rabbit Congress on June 10-13,
2008 in Verona, Italy. Pp. 763-767.http://world-rabbit-science.com/WRSA-
Proceedings/Congress-2008-Verona/Papers/N-NguyenVan2.pdf
OSAKWE, I. and O. EKWE, 2007. Variation in relative palatability of different forages
fed to rabbit. Animal Research International 4(1): 608-610.
POND, W. G., D. C. CHURCH and K. R. POND.2005. Basic Animal Nutrition and
Feeding. 5th ed..New York: Wiley.
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Rabbits | FORTES, MADELINE D. APRIL 2013
RÖDEL, H.G, 2005. Winter feeding behaviour of European rabbits in a temperate zone
habitat. Mammalian Biology/ZeitschriftFürSäugetierkunde, 70: 300-306. In N.
Somers, B. D’Haese, B. Bossuyt, L. Lens and M. Hoffmann. 2008. Food quality
affects diet preference of rabbits: experimental evidence. Belg. J. Zool., 138 (2) :
170-176.
SICILIANO,T. , N. DE TOMMASI , I. MORELLI , and A. BRACA. 2004. Study of
Flavonoids of Sechium edule Jacq. Swartz (Cucurbitaceae) Different Edible
Organs by Liquid Chromatography Photodiode Array Mass Spectrometry. J.
Agric. Food Chem.52 (21):6510–6515.
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
FORTES, MADELINE D. APRIL 2013. Preference and Acceptability of Chayote
(Sechium edule Jacq. Swartz) Fruits and Leaves by Rabbits. Benguet State University. La
Trinidad, Benguet.
Adviser: Dr. Sonwright B. Maddul, PhD.
ABSTRACT
This study aimed to determine the palatability and acceptability of fresh chayote fruits
and leaves as feed for rabbits. A total of five New Zealand White rabbits were distributed
using the completely randomized design to the following treatments: T1 = chayote young
leaves, T2 =chayote mature leaves and T3 = chayote fruits. The mean dry matter content
of the test diets were 10.05, 12.85, and 6.36%, respectively. Among the three diets offered,
young leaves were preferred most by the experimental rabbits. Acceptability of the test
diets did not differ and was observed to be quite low.
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
INTRODUCTION
The domestic rabbit (Oryctolagus cuniculus) is a herbivore that feed by grazing on
grass, forbs, and leafy weeds. Consequently, the diet contains large amounts of cellulose,
which is hard to digest. This problem is solved by autocoprophagy in which rabbits reingest
their own soft feces (Hirakawa, 2001) rather than chewing the cud as do other herbivores
to digest their food further and extract sufficient nutrients. Feeding an appropriate diet to a
rabbit is probably the single most important factor in maintaining its health.
Due to high cost of feeds, rabbit raisers keep on trying different alternative feeds
and supplement to meet the requirement for excellent upkeep of rabbit. This situation is
also made worse during dry season when green feeds are scarce. The challenge is to make
use of feed material that could be available locally. The feeding of alternative forage to
rabbits, especially in the dry season, is essential when grass and herbaceous forages are
scarce. Sechium edule or chayote remains green most of the year and provides nutrients,
being rich in amino acids, vitamins and minerals that are most often lacking in the dry
season. However, there needs to further investigate the use of this plant because of its
relative availability as alternative feed resource to rabbits (http://www.botanical-
online.com/english/chayoteproperties.htm). Aung et al. (1990) mentioned that in addition
to its fruits, chayote yields tender shoots for use as vegetable greens, vines as ornament for
fences or as animal fodder, and edible subterranean storage roots.
However, acceptability of feeds by rabbits is a predicament in feeding and nutrition
research. Pond et a.l (2005) mentioned that in essence, palatability is the result of a
summation of many different factors sensed by the animal in the process of locating and
consuming food. Palatability is determined by the appearance, odor, taste, texture,
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
temperature and other sensory properties of the food. These properties are, in turn, affected
by the physical and chemical nature of the feed.
The palatability of forages is an important factor in rabbit production, particularly
when the forages are expected to provide a major part of the daily nutrient intake. In
research, palatability usually is measured by giving animals a choice of two or more feeds
so that they can express more preference. Freshness is important to the rabbit, because this
affects the palatability of the feed.
Specifically, the study aimed to:
1. determine the palatability of chayote as feed for rabbits, and
2. determine the acceptability of chayote by rabbits.
The palatability and acceptability tests were carried out from July to August, 2012
at Upper Tomay, La Trinidad, Benguet.
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
REVIEW OF LITERATURE
In selecting herbage for rabbits, the most important factors for consideration are:
availability of the browse, the crude protein level, the digestibility factors and toxic
constituents. However, the majority of previous studies are on browse plants such as
grasses and legumes, and no literature on the use of chayote as animal feed was available
to the researcher. Hence, only general information on chayote was reviewed.
Grass, both fresh and dried, is an important food for the domestic rabbit, although it
varies very considerably. During the spring the grass grows rapidly, and at this period the
plant is leafy and is rich in protein and low in fibre content. During summer when the plant
flowers, there is a great increase in fibre and a reduction in protein and other digestible
nutrients. The grass improves slightly in autumn, and then tails off again during winter.
Titus young quickly growing grass is an excellent food for all classes of stock, although
older grass is not so valuable, and rank old growth is not at all satisfactory, these variations
are important, for young rabbits may easily starve if fed on old growth (Cheeke, 1987).
The relative palatability of forages fed to rabbits was studied by Osakwe and Ekwe
(2001). Significantly differences (P<0.01) in relative palatability index (RPI) were detected
among the different forages offered. Based on their RPI, rabbits preferred in descending
order of magnitude Centrosema pubescens, Calopoganimar muconoides and Elacis
guincensi (RPI> 95%) to Musa sapientum (RPI>70%) and Andropon gayanas (RPI>40%).
The preferences of oil polar leaves to banana leaves according to RPI are an interesting
observation from the study.
The chayote is used mainly for human consumption. The fruit, stems and young
leaves as well as the tuberized portions of the roots are eaten as a vegetable, both alone and
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
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plain boiled, and as an ingredient of numerous stews. Because of its softness, the fruit has
been used for children's food and drinks like juices, sauces and pasta dishes. In Mexico, an
attempt has been made to increase the life of the fruit by drying it. The results have been
positive and have enabled jams and other sweets to be prepared while also producing dried
fruit which can be used as a vegetable after a certain time. Because of their flexibility and
strength, the stems have been used in the craft manufacture of baskets and hats. In India,
the fruit and roots are not only used as human food but also as fodder (Bermejo and León,
1994).
The chayote root is not much utilized for food by the Cordillerans, unlike Mexico’s
indigenous Mayans who also eat the starchy roots – like the fruits and tops – and added it
to beans. Chayote was also the staple food of the indigenous Aztecs in Mexico. At present,
chayote can be prepared and eaten raw as salad. It may be stuffed and baked and may be
prepared mashed, fried or boiled. It can also be used as soup or cream. Unknown to many;
however, the chayote is also a medicinal plant. Its leaves can be made into tea. It can
dissolve kidney stones. On the other hand, it is also used to treat hypertension and
arteriosclerosis, according to an article on chayote history and lore on the Internet (Allad-
iw, 2005).
Samples of Sechium edule, also known as vegetable pear or mirliton, were analyzed
for moisture and dry matter. Dry matter was further analyzed for crude protein, ether-
extractable material, pectin, crude fiber, ash, selected minerals, and nitrogen-free extract.
Fresh mirlitons contain 94% moisture. Carotene was not detected. The mirliton does not
contain detectable amounts of lipoxygenase or polyphenol oxidase activity (compared to
activity in mushroom). Amino acid concentrations in the seed were approximately twice
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
those of the flesh. Methionine was detected in the seed but not in the tissue. The data
suggest that the mirliton can be a new fresh vegetable crop for the southern area and for
processing into frozen food products (Flick et al., 1977).
Presently, only one study was reported to see the effect of feeding fiber from
chayote on biological utilization of diet in the rat (Modgil and Modgil, 2004). Chayote had
better biological value then the bottle gourd. Increase in fiber even from vegetable sources
resulted in the decreased PER, DMD, BV, TPD, NPU, PRE and NPR in rats.
The edible parts of S. edule (fruit, seed, stem and root) are relatively low in fibre,
protein and vitamins compared with other vegetables. Nevertheless, they have a high
caloric and carbohydrate content, especially in young stems, root and seed, and the micro
and macronutrient content of the fruit is adequate. The fruits, and the seed especially, are
rich in several important amino acids such as aspartic acid, glutamic acid, alanine, arginine,
cistein, phenylalanine, glycine, histidine, isoleucine, leucine, methionine (only in the fruit),
proline, serine, tyrosine, threonine and valine (Flores, 1989 as cited by Lira, 1996).
A liquid chromatography−mass spectrometry (LC-MS)-based method was
developed by Siciliano et al., (2004) for the characterization of flavonoids from edible parts
of Sechium edule (Jacq) Swartz. Eight flavonoids, including three C-glycosyl and five O-
glycosyl flavones, were detected, characterized by nuclear magnetic resonance
spectroscopic data, and quantified in roots, leaves, stems, and fruits of the plant by LC-
photodiode array-MS. The glycine moieties are represented by pigenin and luteolin, while
the sugar units are glucose, apiose, and rhamnose. The results indicated that the highest
total amount of flavonoids was in the leaves (35.0 mg/10 g of dried part), followed by roots
(30.5 mg/10 g), and finally by stems (19.3 mg/10 g).
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
MATERIALS AND METHODS
A. Dietary Palatability Test
Experimental animals. A total of five mature rabbits (3 months old) were used in
the study. The rabbits were of the same age, weight and breed (New Zealand White) and
were purchased from a single source to minimize variations. The animals were treated
against endo-and ecto-parasites following recommended practices. The rabbits were
housed individually in elevated cages made of metal framework and wire screen.
Preparation of test diets. Fresh chayote fruit and leaves with petiole and tendrils
were collected within 24 hours. The unpeeled fruits were chopped into four equal parts,
while the leaves were offered upon after collecting. The fruit and leaves served as dietary
treatments:
T1 = Chayote young leaves including petioles and tendrils
T2 = Chayote mature leaves including petioles
T3 = Chayote mature fruit (unpeeled)
Experimental procedure. The experimental animals were given a choice from
several diets or feedstuffs. The relative intakes of the diets were measured quantitatively
to represent the response of the animals. The cafeteria-style was used in which rabbits are
given a selection of different food items presented in equal amounts simultaneously.
The preference trial lasted for 10 days in two phases: protocol conditioning and
preference testing. A 5-day conditioning phase was necessary for familiarizing animals
with each test diet. Following the protocol conditioning phase, a preference trial was
conducted over 5 days. Data on the amount of feed offered and left-overs were gathered
during the last phase.
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
Each feedstuff was weighed and offered simultaneously in separate containers.
Rabbits were offered an initial amount of 1 kg of the test diets twice daily at 6:30 am and
5:00 am. This amount was adjusted based on actual intake during the conditioning phase.
Sufficient feed was placed in each container so that feed would not be depleted and force
the rabbits to eat other feeds. Any feed remaining from the previous feeding was weighed
to determine amount consumed before the containers are refilled. The location of the
containers in the cages was randomized at each feeding to prevent bias due to position.
Drinking water was supplied ad libitum in earthen containers or crocks.
B. Dietary Acceptability Test
The dietary acceptance trial made use of the single choice selection in which
experimental animals were not given a choice of diets. Only one test diet was offered to
the experimental rabbits at a time for a period of 30 minutes. The same dietary treatments
were tested in this trial to involve the same experimental animals used in the palatability
trial.
Each rabbit was offered an amount of 1 kg of T1 (Chayote young leaves including
petioles and tendrils) at 6:30am for two days. The diet was withdrawn from the animals 30
minutes after this was offered and weighed for leftovers. At this time, the animals were fed
with a basal diet of Galinsoga forage for the rest of the day. Another test diet (T2 = Chayote
mature leaves including petioles) was offered in same amount and period of time over two
days. The last test diet, (T3 = Chayote fruits), was offered in same amount and period for
the last two days of the experiment.
Samples of the test diets were dried at 60 °C for 24 hours in a Memmert convection
oven for dry matter determination.
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
Data Gathered
The following data were gathered from both experiments:
1. Amount of feed offered daily(g).The amount of each test diet given to an
experimental animal was measured daily using a feed scale.
2. Amount of feed leftover (g). The amount of feed not consumed by each
experimental animal was also weighed before a new feed was given in the morning.
3. Weight of feed samples before and after drying (g). The weights before and
after oven-drying were used to compute for dry matter content.
Data Computed
From the data gathered, the following indicators were computed:
1. Amount of dry matter in feed (g). The amount of dry matter in the test diet
was computed as:% DM = Weight of Feed Samples after Drying X 100
Weight of Feed Samples before Drying
2. Total feed intake, fresh basis (g). This was obtained by getting the
difference between the amount of feed refused and feed offered to each experimental
animal.
3. Total feed intake, dry matter basis (g). This was computed by multiplying
the total feed intake, fresh basis, of each animal with the DM content of the test diet it
consumed.
4. Relative palatability index. This was calculated as:
Relative Palatability Index: Daily Feed Intake X 100
Highest feed intake
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
5. Relative acceptability index. This was calculated using the formula:
Acceptability Index = Amount of Feed Consumed X 100
Amount of Feed Offered
Data Analysis
All data were subjected to one-way analysis of variance for Completely
Randomized Design of an experiment. In case of significant differences, treatment means
were compared using the Duncan’s Multiple-Range Test.
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
RESULTS AND DISCUSSION
Dry Matter Content of Chayote
Table 1 shows the dry matter content of the experimental diets. Statistical analysis
revealed that dry matter content is significantly different among the parts of chayote used
in the experiment. As expected, the fruit has the lowest dry matter content at 6.36% only.
Flick et al. (1977) reported that fresh chayote fruits contain 94% moisture or 6% dry matter.
Chayote young leaves including petioles and tendrils contained 10.05% dry matter. The
mature leaves including petioles had the highest dry matter content (12.85%). These figures
are within the values reported by Nguyen Van and Nguyen Thi (2008) for water spinach
(9.63%) and sweet potato vine (8.56%).
Preference of Test Diets by Rabbits
Data on feed intake of the experimental animals are presented in table 2. Both daily
and total feed intakes are significantly different among dietary treatments. Young leaves
of chayote were ingested by the rabbits with the greatest amounts both in total and daily
intakes (824.64 g and 164.93 g, respectively). This implies that among the three diets
offered young leaves were preferred by the experimental rabbits.
Table 1. Dry matter content of the test diets
TREATMENTS MEAN ____________
Chayote young leaves
10.05b
Chayote mature leaves
12.85a
Chayote fruits
6.36c
**Means with the same letter superscript are significantly different (P<0.05) by DMRT.
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
Table 2. Mean feed of the test diets by rabbits during the palatability trial
TREATMENTS
TOTAL DAILY
FRESH BASIS (g) _ FRESH BASIS (g)
Chayote young leaves 824.64a 164.93a
Chayote mature leaves
717.04b 143.41b
Chayote fruit 745.08b 149.02b
Means with the same letter superscript are not significantly different (P<0.05) by
DMRT.
Total intakes of fruits and mature leaves are similar at 745.08 and 717.04g, respectively.
Similarly, daily intakes of fruits and mature leaves are not significantly different (149.02
and 143.41 g, respectively). According to Baumont et al. (2000), for a given plant,
ingestibility is dependent on the vegetation stage and the number of the vegetation cycle.
During the first vegetation cycle, ingestibility decreases with the age of the plant. Ball et
al. (2001) further explained that maturity at harvest also influences forage consumption by
animals. As plants mature and become more fibrous, forage intake drops. This preference
for high quality forage has been suggested for rabbits by Kuijper et al. (2004) and Rödel
(2005) as cited by Somers et al. (2008).
Relative Palatability Index
Table 3 shows the relative palatability and preference ranking of chayote diets by
rabbits. Statistical analysis showed no significant differences among treatments. Based on
numerical value, rabbits preferred in descending order of magnitude chayote young leaves
(96.56 %), mature leaves (92.66 %), and fruits (86.94%). The exact reasons for the
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
Table 3. Relative palatability index and preference ranking of the test diets
TREATMENTS RELATIVE PALATABILITY PREFERENCE
INDEX, %ns RANKING
Chayote young leaves 96.56
1st
Chayote mature leaves 92.66
2nd
Chayote fruit
86.94
3rd
Means with the same letter superscript are not significantly different (P<0.05) by DMRT
differences in relative palatability of rabbits fed different forages is not known, and could
not be explained by this study. This is because palatability is a complex phenomenon
determined by dietary type and environmental variables (Molyneux and Ralph, 1992 as
cited by Osakwe and Ekwe, 2007).
Acceptability of Test Diets by Rabbits
Table 4 presents the data on feed intake of the experimental diets in daily and total
basis. Chayote mature leaves had a mean daily acceptance of 96.23 g within a 30-minute
period, followed by chayote fruit at 89.04 g. Young leaves were consumed at a mean of
61.73 g per day. However, treatment differences were found to be non-significant (P<0.05).
Thus, the part of chayote as feed had no effect on acceptability by rabbits. Data show that
experimental rabbits had the same acceptability of the different parts of chayote. The mean
daily feed intake of the fresh test diets by rabbits is 82.33 g
Acceptability Index
The effect of chayote part on relative acceptability index within the allowed
foraging time is shown in table 5. Analysis of variance revealed no significant differences
among the treatment means. It was observed, however, that test diets had low acceptability
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
(6.17 - 9.62%) by rabbits within a period of 30 minutes only. This can be due to the very
short duration at which the diets were made available to the test animals.
Table 4. Mean feed intake of the test diets by rabbits during the acceptability trial
TREATMENTS
TOTAL DAILY
FRESH BASIS (g) FRESH BASIS (g) __
Chayote young leaves
370.40 61.73
Chayote mature leaves
577.40
96.23
Chayote fruit 534.20
89.04
Means with the same letter superscript are not significantly different (P<0.05) by DMRT.
Table 5. Relative acceptability index and ranking
TREATMENTS ACCEPTABILITY ACCEPTABILITY
INDEX, % RANKING
Chayote young leaves
6.17 3rd
Chayote mature leaves
9.62
1st
Chayote fruit
8.89
2nd
Means with the same letter superscript are not significantly different (P<0.05) by
DMRT.
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS
Summary
The tests on preference and acceptability of chayote fruits and leaves by domestic
rabbits were carried out from July to August, 2012 at Upper Tomay, La Trinidad, Benguet.
Fresh chayote fruits and leaves with petiole and tendrils were collected within 24 hours.
The unpeeled fruits were chopped into four equal parts, while the leaves were offered upon
after collecting. The fruits and leaves served as dietary treatments: T1 = Chayote young
leaves including petioles and tendrils; T2 = Chayote mature leaves including petioles; and
T3 = Chayote mature fruit (unpeeled).
A total of five mature rabbits (3 months old) of the New Zealand White breed were
used in the palatability trial which lasted for 10 days and in acceptability trials carried out
in two days for each part of chayote. In the palatability trial, the cafeteria-style was used in
which rabbits were given a selection of the diets presented in equal amounts
simultaneously. Rabbits were offered 1 kg of the test diets in separate containers twice
daily at 6:30 AM and 6:00 PM. The location of the containers in the cages was randomized
at each feeding to prevent bias due to position.
The same dietary treatments were tested in the acceptability trial involving the same
rabbits used in the palatability trial. Only one test diet was offered to the experimental
rabbits at a time for a period of 30 minutes. Each rabbit was offered an amount of 1 kg of
T1 (Chayote young leaves including petioles and tendrils) at 6:30am for two days. The diet
was withdrawn from the animals 30 minutes after this was offered and weighed for
leftovers. At this time, the animals were fed with a basal diet of Galinsoga forage for the
rest of the day. Another test diet (T2 = Chayote mature leaves including petioles) was
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
offered in same amount and period of time over two days. The last test diet, (T3 = Chayote
fruits), was offered in same amount and period for the last two days of the experiment.
Samples of the test diets were dried at 60 °C for 24 hours in a Memmert convection oven
for dry matter determination.
Among the parts of chayote used as test diets, young leaves were preferred most by
the experimental rabbits. However, chayote fruits and leaves have low acceptability by
rabbits.
Conclusions
Relative palatability was affected by the part of chayote as test diet. Young leaves
were preferred most by rabbits. Chayote fruits and leaves had no apparent effect on
acceptance by rabbits. Thus, the fruits, mature and young leaves including petioles and
tendrils can be fed to rabbits.
Recommendations
Fresh chayote fruits, unpeeled and quartered, and the leaves whether mature or
young, including petioles and tendrils, are recommended as alternative feed for rabbits.
These local resources are especially beneficial during shortage of feed supply. Moreover,
this finding has to be confirmed in a feeding trial involving growing and fattening rabbits.
Preference and Acceptability of Chayote (Sechium edule Jacq. Swartz) Fruits and Leaves by
Rabbits | FORTES, MADELINE D. APRIL 2013
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