20.1.1 Introduction

 

The use of non-domesticated animals ( wildlife ) as sources of meat and other animal products is not new. Since the earliest appearance of man on earth wild game has been a source of meat. This was long before man domesticated a limited number of animal species. Today wild animals continue to make substantial contributions to the diets of some indigenous peoples in a limited number of tropical countries. Apart from its protein contribution to the diet of rural communities, there are regions within the tropics where the non-protein products of wild animals such as hides and skins, are a viable industry.

 

A notable limiting factor in the development of a wildlife-based industry is the sustainability of the resource. The domestication of some of the existing wildlife species and their management in captivity is one means of making available a continuous and reliable supply of these animal resources. There is also merit in the use of locally available wildlife species in preference to exotic traditional livestock species, some of which have proven to be poorly adapted to tropical environments with low levels of management.

 

To the person wanting to preserve or protect wildlife it is better to work with the indigenous species as they are better able to sustainably exploit resources of the ecosystem to which they belong. An added advantage anticipated in using domesticated or semi-domesticated wild game species, is that animal health, slaughter, processing and marketing problems could be minimized.

 

The immediate disadvantage is that when a wild species is being domesticated, it usually takes many years before a sufficient number of animals are available for commercial production. There is less pessimism here, as the scientific advances in animal behaviour and genetic studies can certainly contribute to reducing the time frame for providing a workable group of animals.

 

This is certainly an area which poses a potential conflict between the habitat conservationist [ those who wish to see the wild animals kept in their natural habitat ] and the production oriented animal scientist as far as it relates to threatened or endangered species. It is an important area for conflict resolution as if we do not either know how to set up intensive systems of production for this group of animals or we fail to get their population numbers up to viable levels ALL these animals would be soon extinct. Therefore there would be only loosers.

 

The School of Developing Animal Production Systems Modelling will therefore have an important role to perform, for all species of non-domestic animals, if all are to win in the Conservation Race. We may, however, be running out of time.

 

The taxonomic order Artiodactyla, the even-toed ungulates, includes most of the mammals that have been domesticated by man, or serve as a major source of animal protein (Table 1). The order includes the members of the sub-orders Suiformes, Tylopoda and Ruminantia. The Tylopodes include such animals like camels and llamas, The Rumanantia includes the bovines ( dairy and beef cattle and water buffalo ) and caprines ( sheep and goats ). The families that comprise the sub-order Suiformes include such animals like pigs and hogs, peccaries and hippopotamuses. Pigs and hogs belong to the family Suidae, while hippopotamuses belong to the family Hippotamidae.

 

Peccaries belong to the family of even-toed, hoofed mammals referred to as the Tayassuidae, and peccaries are unique to the New World. There are three (3) living species of peccaries:
1. the collared peccary (Tayassu tajacu );
2. the white lipped peccary (T. pecari ); and
3. the Chacon peccary (Catagonus wagneri ).

 

Superficially, peccaries and true pigs (Family Suidae) look alike and they have many similar habits, but are genetically different.

 

Table 1: Taxonomy of the Collared Peccary (Tayassu tajacu)

Order	Artiodactyla
Sub-Order	Suiformes			Tylopoda	Ruminantia
Family	Suidae	Tayassuidae	Hippopotamidae
Genus	Sus sp. Hylocherus sp. Potamocherus sp. Babyrousa sp.	Tayassu sp. Catagonus sp.	Hippopotamus sp. Choeropsis sp.
Common Names	pigs, hogs	peccaries	hippos	camels	bovines, caprines and antelopes

Source:  Adapted from Simpson (1984)

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20.1.2 Where is the Javerlina or the Quenck found in the world?

 

The species Tayassu tajacu and T. pecari are native to Neotropical rain forests. The Chacon peccary is limited to the dry thorn forests of the South American Chaco. The ranges of both Tayassu species, extend further north and south than its native neotropical forests, into drier scrub semi desert areas. Geographically, the collared peccary has one of the largest ranges of any living ungulate. Its range extends from Texas and Arizona in the north to northern Argentina in the south. Within its geographic range, it has inhabited a wide variety of vegetative types including desert shrub, arid woodland, and tropical rain forest, and this animal has adapted itself to many climatic conditions. Like many native American mammals, the original range of the collared peccary has been reduced since the arrival of Europeans into the New World.

 

20.1.2.1 Under what conditions do Javelinas or Quenks live in the Wild?

The collared peccary by virtue of its range is shown to inhabit a diversity of habitat types. In the northern part of the range, the peccary is seen to inhabit desert, semi-desert, dry hill sides and brushy valleys. In Panama and Costa Rica they have existed in habitats of both coastal lowlands and at altitudes of 2,480 m above sea level. It also inhabits coastal forests, including many other vast areas of Central America, where the forests are dense and humid, with no openings or clearings.

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20.1.3 Description of the Javelina or Quenk

 

The collared peccary is a small ungulate which resembles a small pig. The upper parts are uniformly of grizzled gray black, with a faint but distinct collar or stripe of pale yellow hairs from the top of the shoulder forward to the lower cheek. It has a large head in comparison with the rest of the body, and which tapers sharply from large jowls to a narrow nose. The nose is a naked pink, the legs are fine and slender. The fore feet end in two (2) large toes, and have two (2) smaller rear toes that do not touch the ground (i.e. do not appear in tracks). On the hind feet there are two (2) large toes, and one (1) smaller one. The tail is abortive, measuring only about 1.27 cm in length.

 

Three of the most striking anatomical differences between the peccary and the common pig are:

(i) the presence of a subcutaneous scent gland in the peccary, this gland is generally covered by the animal’s stiff hairs and becomes visible when the hairs are erected as a result of stress or excitement;

(ii) the absence of the inner dew claws on the hind feet and

(iii) the upper canines which are well developed in the male peccaries and directed downwards, these canines are not like those of the wild suids which are sharply curved and flared.

 

20.1.3.1 External Features

Peccaries living at its northern limit are affected by climatic changes. The colors of the individual hairs are generally black, with whitish annulations. There is an erective mane that tends to be blacker than the long hairs on the sides of the belly. The mane extends from the occiput to the scent gland on the rump. The collar of whitish hair crosses the hind part of the neck, and extends obliquely upwards and backward from the front of the shoulder to the black mane on the back. Seasonal variations in hair lengths occur. The highest density of hairs per square metre is usually along the mane, and this density decreases in summer due to the loss of hair. The animals appear lighter in color during summer months than in the winter months.

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20.1.3.2 Body Size

The head and body of the adult peccaries range from 750 mm to about 1,000 mm, the shoulder height is 440 - 575 mm. In Arizona the average body weight is about 19.3 kg for boars, and a weight of 14.8 kg and 13.6 kg for sows.

 

But there is a wide weight range among adult animals, varying from 11.4 kg to almost 31.8 kg. The wide range in adult weights were as a result of the quality and quantity of food the animal can obtain. The peccaries from Central and South America seem smaller than those from Texas and Arizona.

 

In collared peccaries no obvious sexual differing characters exist, except the appearance of the scrotum when males are observed at a close range. Both males and females were shown to attain adult weight at about 40 weeks. Weights exceeding those reached in about 40 weeks were generally found to be due to excess fat. Maturity is reached when the animal is about 40 weeks of age. In some instances, when animals are kept on a good quality diet, they continue to grow slowly until about one year of age.

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20.1.4 The Stomach and Digestive System of the Javelina or Quenck

 

The anatomy of the peccaries’ teeth, jaws and digestive system is indicative of foods eaten. The types of foods eaten by the collared peccary are fruits, underground tubers, rhizomes and bulbs, green grass and green shoots. Peccaries have a well developed snout used to root out bulbs, roots and tubers. In the moist rain forest areas, reports show the peccaries’ diet to include palm fruits, roots, snakes, grubs and caterpillars, insects and frogs.

 

Peccaries are described in Arizona as a ‘generalist herbivores’. In assessing the stomach contents of peccaries inhabiting rain forests, on average, plant reproductive parts constituted most of the finely ground material, followed by vegetative material, and then trace amounts of animal material. Rain forest peccaries are primarily frugivores ( fruit eaters). In captivity the related species T. pecari was fed twice daily on carrots, yeast, wheat salad, seasonal vegetables and a small quantity of minced meat. At the Emperor Valley Zoo (Trinidad & Tobago), the diet has been similar.

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20.1.4.1 Teeth and Dentition

The collared peccary has the dental formula:
Incisors 2-2/3-3,
Premolars 3-3/3-3,
Canines 1-1/1-1,
Molars 3-3/3-3,
making a total number of 38 teeth.

 

The permanent dentition of the peccary is obtained at 74 to 94 weeks. The collared peccary is one of the few non-carnivorous mammals that possess large and sharp canine teeth. The upper canines are directed straight down, and the lower ones straight up and rub against each other thus maintaining a sharp cutting edge. The canines are of little value for eating. They are modified into tusks but are small and grow to a length of 30 - 35 mm.

 

They are however of importance for:
(i) use as a defense mechanism against enemies;
(ii) display during squabbles between herd members;
(iii) generation of loud, clacking sounds of chatter as warning threats to enemies; and
(iv) use in intraspecific situations.

 

These long interlocking canine teeth greatly reduce the sideways chewing motion of the mandible and as such the only extensive chewing of food that can occur is an up and down movement which crushes the food. The incisors of the collared peccary are well adapted to cropping the vegetation which is swallowed after a minimum of chewing.

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20.1.4.2 Stomach

The peccary has a unique digestive system and has been regarded as a pseudo-ruminant that has an enlarged fore-stomach which is divided into four (4) separate compartments. These compartments are described as: a gastric pouch, two blind sacs and a glandular stomach. The blind sacs together with the gastric pouch, form the fore-stomach. The fore-stomach volume is 85% of the total stomach volume, which is less than those in other ruminants: sheep - 90% or cattle - 88 or 91%. Table 2 shows volumes of the caecum and different compartments of the stomach of the collared peccary.

 

Table 2: Volumes of caecum and different compartments of the stomach of Tayassu tajacu. Relative volumes are expressed as percentages of total stomach volume

Compartment	Absolute Volume (cm3)	Relative Volume (%)
Upper Blindsac	130	11.3
Anterior Blindsac	340 985	29.4 85.3
Gastric Pouch	515	44.6
Glandular Stomach	170	14.7
Total Stomach	1.155	100
Caecum	200	17.3

Source:  Adapted from Langer (1979)

 

The fore-stomach of the peccary have been reported to have an acidity or a pH of 5.0 to 6.2, and this is capable of sustaining a microbial population like that of the ruminant. In an attempt to show the close relationship of the peccary’s digestive system to that of ruminants, features of the peccary’s stomach which are similar to ruminants were as follows:
(i) the possession of a fore-stomach of cornified epithelium;
(ii) anlage of a sulcus ventriculi; and
(iii) cardiac glands found oral to the fundic glands.

 

Differences highlighted were as follows:
(i) the peccary’s inability to chew its ingesta as efficiently as ruminants; and

(ii) neither grasses nor leaves play a major role as a food source.

 

Moir et al. (1956, 1965) and Langer (1975) have been cited by Langer (1979) as providing six (6) criteria of ruminant-like digestion. These are shown as they relate to the stomach of the collared peccary:

(a) Gastric Chambers store the digesta and slow its rate of passage through the stomach - the fore-stomach of the peccary forms a storage chamber for food. Folds slow down the rate of passage of food through the stomach (Langer, 1979).

 

(b) Micro-organisms help to digest the food - microbes are active in the stomach which is confirmed by the presence of volatile fatty acids (Carl and Brown, 1983; Langer, 1979 citing Dyson, 1969). Volatile Fatty Acid (VFA) concentrations have been found to be seven times as high as in the caecum. Ten times as high as the concentration in the anterior intestine, but only one-third to half of that found in the ruminant fore-stomach. These comparative concentrations having been presented by Dyson (1969), cited by Langer (1979).

 

(c) Microbial fermentation products are absorbed through the stomach wall - both Langer (1979) and Carl and Brown (1983) indicated that the importance of VFAs in the diet was not easily determined. This was based particularly on the vagueness of the level of absorption of volatile fatty acids [VFAs]. Langer (1978) cited by Carl and Brown (1983), found no development of papillae in the peccary’s fore-stomach. Papillae are common in the rumen, and are known to function in VFA absorption (Carl and Brown, 1983 after Church, 1979). The possibility of trans-epithelial absorption of VFAs exists by virtue of the fact that the thickness of the wall of the peccary’s fore-stomach is similar to that of the rumen, reticulum and abomasum of ruminants (Langer, 1978 cited by Carl and Brown, 1983).

 

(d) The host makes use of vitamins produced by the microbes - vitamin B levels in the diet were found to be low. This led researchers to believe that the level of vitamin B requirements were either low, or that they were met by microbial synthesis within the gut (Dyson, 1969 cited by Langer, 1979).

 

(e) With the help of microbes non-protein nitrogen can be used by the host - there was no conclusive evidence for the assimilation of non-protein nitrogen (Dyson, 1969 in Langer, 1979).

 

(f) In the young animal an effective ventricular sulcus is necessary (Langer, 1979 citing Black and Sharkey, 1970) - a ventricular sulcus is found in the adult collared peccary (Langer, 1979). The structure in the adult appears to enable a bypass of the fore-stomach by fine particles and liquids.

 

Langer (1979) found that the available data on the physiology of the digestive system of the peccary was inadequate to allow for a proper classification of the animal as a fore gut or hind gut fermentor.

Other authors have felt that the digestibility of feeds by the peccaries was more closely related to the single stomached animals like the swine than that of ruminants. However we believe that the javelina or quenk has a flexible digestive system, i.e. it can digest feed both like a single stomached animal and like a ruminant. This may be an adaptive mechanism so that maximum digestion of feeds could take place based on the types of feeds available in the diverse habitats of the peccary.

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20.1.5 Reproduction in the Quenck

The collared peccary is the only wild ungulate of the Western Hemisphere which has a long breeding season. Under favourable conditions in captivity, the collared peccary will breed and reproduce readily.

 

20.1.5.1 Males

For an adult male (3.5 years), the following dimensions were recorded:

• Testes - 4.35 cm long; 3.18 cm in diameter
• Vas Deferens - 14 cm long
• Terminal Ampulla - absent
• Seminal vesicles (triangular) - 6.5 cm x 3.8 cm x 2.54 cm in depth
• Prostrate gland - 1.9 cm in diameter
• Bulbourethral gland (elongated tube) - 8.26 cm long x 2.6 cm in diameter
• Penis (cork screw/reverse flexure) - 14 cm

Young males become sexually active at approximately one year and as early as 46 - 47 weeks. Sperm production declines after seven (7) years. Sperm production was found to be sufficient throughout the year for fertilization, allowing the possibility of breeding during all months of the year.

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20.1.5.2 Females

The uterus is described as bicornate and small. The tubes and ovaries are materially different from that of the domestic sow. The collared peccary, based on work conducted in North America, is found to be a continuous breeder in captivity. This has also been observed at the Emperor Valley Zoo in Trinidad, Republic of Trinidad and Tobago.

 

When females failed to become pregnant, the oestrous cycle was repeated over the entire year. These advantages give the species a very high breeding potential. Data on captive animals in Arizona, estimated the length of the oestrous cycle to be between 22.6 - 24.6 days, and that estrus lasted for between 3.5 and 4.8 days, safely one could say 4 days.

 

Young females breed for the first time when they approach one year, and this have occurred even in wild populations. In captivity, young females have been known to reach breeding conditions in about eight (8) months, but is has occurred as early as 44 weeks (6.5 months) in Texas. The breeding weight has been estimate at 16 kg, and the weight at parturition was taken at 23 kg. The parturition weight was retained as the adult weight. The collared peccary has been suggested to be a prolific breeder as captive animals have given birth for up to 14.5 years. Death and disease were the only factors affecting their ability to bear young.

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20.1.5.3 Gestation

For the collared peccary in Arizona, an approximate gestation period of 145 days was reported by Sowls (1984). Anon (1975) reported a range of 140 - 158 days in South America. Lochmiller et al. (1987) obtained a gestation interval ranging from 143 - 147 days for wild caught females bred in confinement. Therefore about 146 days seems safe to work with.

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20.1.5.4 Post-partum heat or sexual receptivity after giving birth

Post-partum heat allows a species to produce young at a faster rate than animals unable to ovulate as quickly after parturition. Among the captive peccaries, copulation resulting in pregnancy was known to occur within three (3) to seventeen (17) days after the young were removed from the sow.

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20.1.5.5 Litter Size

Most life history accounts of the collared peccary that the common litter size is two (2). Accounts of 4, 5 and 6 foetuses have been reported. Research on the reproductive tract of animals killed, and from animals in captivity, has shown that 16% of the females gave single births, 73% twins, 9% triplets, and 2% a litter of four (Sowls, 1984).

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20.1.5.6 Lactation

The female peccary appears to have four pairs of mammary glands - two pairs functional, and two pairs non-functional. The milk secretion gradually declines in the terminal stage of lactation, and an estimate of the lactation period was between 6 - 8 weeks. The storage area for milk in the lactating sow is very small, and the conformation of the inguinal region during periods of dryness is little different from its shape during lactation (Sowls, 1984).

 

The milk of T. tajuca is lower in total solids than that of the domestic pig (Sus scrofa) (Nowak, 1991). The lactation period may last for 6 - 8 weeks, but young peccaries may remain with the mother for 2 - 3 months (Nowak, 1991).

 

The peccary throughout its range has shown peak periods of oestrus and pregnancy to coincide with the availability of feed (Sowls, 1984; Anon, 1975). Young born during periods of poor nutrition were found to mate as late as 21.5 months of age (Sowls, 1984). In captive reared facilities, a female fed a poor diet in the last trimester of gestation devoured her young (Sowls, 1984). Under a diet of commercial pig feed, the same animal successfully reared three normal litters. Lutwak-Mann (1962) and Sowls (1984), identified B complex vitamins, ascorbic acid, vitamin E, vitamin A, and essential fatty acids as necessary ingredients in a diet for reproduction.

 

Physiologically the nutritional effect on gestation in the female peccary resembles the responses of the swine (Lochmiller et al., 1987). They suggested that moderate nutritional stress during gestation has minimal impact on litter size, litter weight, and foetal development. In their results they obtained an average daily consumption of 451 g throughout gestation, and noted temperature as affecting daily intake. Weight reductions were observed in pregnant females when fed diets of crude protein levels of 8.4%. Weight loss was assumed to be due to females using their own tissue protein and energy reserves to support placental-foetal demand (Lochmiller et al., 1987).

 

The poor diet also had no influence on litter weight, when only twin litters were considered. The average neonatal weight was 684 ± (SE) 23g. An average one day old weighs 623g (Sowls, 1984). The gestation length was within the range 143 to 147 days (avg.: 146 days) (Lochmiller et al., 1987), and was comparable with the reports of Anon (1975) 140 to 156 days, and Sowls (1984) who said 145 days. Carl and Brown (1985) reported a maintenance nitrogen requirement of 0.815 N/kg0.75 body weight of adult peccaries.

 

Poor diets, Lowe (1970) as cited by Lochmiller et al. (1987) was possibly responsible for greater rates of implantation failures. Females also become anoestrous when fat reserves were depleted (Lochmiller, 1984 as cited by Lochmiller et al., 1987).

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20.1.6 Adaptation to Temperatures and Environments

 

Sowls (1984) in his assessment of the range of habitats of the collared peccary, highlights the uniqueness of this animal to inhabit a wide variety of habitats with so many variations in temperature. Detailed reports of authors like Zervanos (1972, 1975), Zervanos and Hadley (1973), and Zervanos and Day (1977), have been cited by Sowls (1984) on thermoregulation, water relations and energy requirements under changing environmental conditions.

 

Reports show:
-that daily body core temperatures of collared peccaries in Arizona vary from 37.5^oC to approximately 49^oC during all seasons;
- skin temperatures always exceed surrounding air temperatures.

 

These authors have also been cited by Sowls (1984) as having found that the pelage had a poor insulative value. The hairs alterations occurred in relation to the summer temperatures. The outer, darker portions of the bristles broke off, exposing the lighter bristles near the body. This change results in increased reflectance of high energy, short wave radiation and decreased absorbance, an advantage during hot summer months.

 

In temperate conditions, the report of Sowls (1984) in reference to Zervanos (1972, 1975), Zervanos and Hadley (1973), and Zervanos and Day (1977), show that the longer, dark pelage found in winter is advantageous during cold weather. Their absorption of solar radiation helps to keep the animal warm. A significantly higher basal metabolic rate during the winter months, helps compensate for the peccary’s poor insulation (Sowls, 1984). With a higher winter metabolic rate, food consumption is higher (Sowls, 1984).

 

From the research of Zervanos (1972, 1975) it was reported that in the summer period, critical temperatures of 35^oC and 29.5^oC were cited in Sowls (1984), as the thermoneutral zone for the collared peccary. The author Zervanos was also able to show that the collared peccary cannot prevent increased body temperature when exposed to direct summer sun at an air temperature above 30^oC, and wind velocity above 60m/second (Sowls, 1984).

 

To deal with high temperatures Nowak (1991) and Sowls (1984) reported that animals tended to feed and drink between sunset and sunrise (the cooler hours of the day), and bedded down during the heat of the day. To escape the high temperatures, animals seek the shade of rocks or vegetation (Nowak, 1991). Like the domestic pig, peccaries use wallows or at times dust to cool themselves (Nowak, 1991).

 

Bissonette (1982) on water conservation, reported that Zervanos and Hadley (1973) were able to demonstrate that respiratory evaporation was the main avenue of water loss. During dehydration, peccaries reduced evaporative water loss by 68%, and urinary water loss by 93%. The pecarries indicated an adaptive physiological mechanism for conserving moisture under stress, and were able to survive for periods of up to six (6) days without water (Bissonette, 1982).

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