Medicine and Surgery of Camelids. Группа авторов

of Camelidae migrated from North America into Asia to continue the evolutionary process, dying out in North America.

Once in Asia, Camelus radiated through eastern Europe (Romania and southern Russia), the Middle East, and North Africa as far west as the Atlantic and as far south as Tanzania. It is likely that the dromedary evolved from the Bactrian camel, though the hump(s) may be an acquired characteristic of domestication. Wild camels had become virtually extinct in North Africa before historic times (3000 BCE). Only C. bactrianus ferus now exists in the wild state in one small area in the Trans‐Altai Gobi Desert on the border of Mongolia and China, with a limited population of roughly 1000 animals (Figure 1.15) [4, 5, 28].

      South American Camelids

The first SACs migrated to South America at the beginning of the Pleistocene epoch (approximately three million years ago) when an open land connection between North and South America developed [8, 29]. The Isthmus of Panama was formed by volcanic eruptions from the ocean floor, forming a series of islands that ultimately became interconnected (the Caribbean land bridge). The major earliest SAC genus appearing in South America was Hemiauchenia (Tanupoloma), which radiated throughout the flatter regions east of the Andes. During the middle Pleistocene, the genera Palaeolama, Lama, and Vicugna developed from the long‐limbed, flatland‐adapted Hemiauchenia. These genera had shorter limbs, which more easily adapted them to the mountainous Andes.

Various species of Palaeolama migrated back to North America. Fossils associated with North American Hemiauchenia have been found along the Gulf Coast and Florida (Figure 1.16) [30].

Table 1.2 Characteristics of South American camelids.

Characteristic	Vicuña	Alpaca	Guanaco	Llama
Types/breeds/subspecies/races	Peruvian – Apron or bib on frontal chest	Huacaya – Fibers with light crimp. Fleece at right angles to body.	May be as many as four subspecies or races	South American breeds: Heavy neck fiber (chaku, lanuda, tapada)
	Argentine – No chest bib	Suri – Fiber lacks crimp. Fleece hangs in ringlets.		Short neck fiber (ccara, pelada). No North American breed standards. Alpaca and Llama Show Association show classification: Light, medium, and heavy wool divisions.
Conformation
Topline	Straight with rounded rump	Straight with rounded rump	Straight or slightly rounded from withers to tail	Straight from withers to tail
Head and neck carriage
Alert	Vertical	Vertical	Vertical	Vertical
Resting	Vertical	15° from vertical	Vertical	Vertical
Ears	Short, curved on both borders	Short, spear‐shaped, curved on both borders. Huacaya – sharp tip. Suri – rounded tip.	Medium length, curved on both borders	Long, inner border straight or curved inward (banana ears)
Face	Short	Short	Medium	Long
Pastern	Sloped	Almost vertical	Sloped	Sloped
Fiber
Diameter in microns (avg.)	10–30 (13–14)	Huacaya – 16–40 (22) Suri – 16–35 (23)	18–24	Undercoat – 16–40 (26) Guard hair – 40–150 (70)
Quality	Finest of all SACs. Staple short.	Excellent. Staple long.	Inner coat is excellent; juvenile pelts are used for fur garments. Staple short.	Variable; inner coat may make excellent garments. Staple may be long or short.
Coverage	Uniform over body, head, and upper legs. No topknot.	Topknot present. Fiber extends below the knee and hock.	No topknot. Uniform over body, head, and upper legs.	Fiber usually doesn't extend much below the knee or hock or onto the face.
Guard hair	The bib and lower body fiber are guard hairs.	Highest‐quality animals have no guard hair.	Concentrated on lower parts of body and limbs.	Numerous.
Color	Color pattern similar to that of guanaco, but the basic body color is a yellowish light brown. The white in front of the rear limbs may extend to the top of the back. Argentine subspecies has long white guard hairs on the chest, but this is extended into a bib (8–14 in./20–35 cm) in Peruvian subspecies.	22 solid colors recognized, ranging from white to black. Multicolored fleeces also produced.	Basic body color light to dark reddish brown (cinnamon) above, whitish hair below (countershading). White extends up behind the foreleg and in front of the rear leg, around the perineum, inside of legs, and up the bottom of the neck. Front and outside of the upper limbs are body color or gray. Head, face, and ears are dark gray to black, with the darkest color over top of the head and bridge of the nose.	Numerous solid colors from white to black. Multicolors (pinto, appaloosa) also seen.
Teeth	Incisors long, narrow (sides parallel) and continue to grow throughout life. Enamel present only on labial side of the incisor teeth.	Incisors elongated and continue to grow into adulthood. Enamel present only on labial side Скачать книгу В начало < 17 18 19 20 21 22 23 24 25 26 > В конец