olfactory contact. The male is then led up from behind to the sitting female with the operator sitting on the left side of the female. As soon as the male has sat down on the
female and makes a few thrusts, the operator grasps the male’s sheath and directs his penis into the AV, and holds it there by manual pressure at the base of the scrotum. The
male will make several thrusts, interspersed by periods of rest, until ejaculation is completed. The ejaculate usually occurs in fractions and this whole process can take
between 5 and 10 min, although it may occasionally last for 20 min or even longer.
Electroejaculation may be employed if collection by AV cannot be achieved, using a Ž
. standard bovine ejaculator Standard Precision Electronics, Denver . The male is secured
Ž .
in sternal recumbency and then turned on his side as described by Tingari et al. 1986 . Depending on the temperament of the individual male, the collection can be done with
Ž or without the use of sedative and analgesic Domosedan Detomidine hydrochloride,
Ž .
. 30–35 mgrkg body weight bwt , i.v., or 70–80 mgrkg bwt, i.m. , which is superior to
other sedatives such as xylazine and acepromazine for obtaining semen by electroejacu- Ž
. lation Jochle et al., 1990 . Ejaculation can be achieved by using the rectal probe
lubricated with a copious amount of jelly to ensure good contact with the mucosa and giving two sets of stimulation, each of 10–15 pulses of 3–4 s duration at 12 V and 180
mA with a rest of 2–3 min between the two series of impulses. The semen is collected into a flask held at the prepucial orifice with occasional milking of the prepuce to expel
all the semen. The volume of semen recovered by electroejaculation is usually less than that obtained by AV, but the other semen parameters are similar.
6. Characteristics of semen
6.1. Ejaculation and semen characteristics of lamoid semen Ž
Ejaculation in lamoids is a continuous process throughout copulation dribble ejacula- .
tion and it occurs with urethral pulses that may vary during copulation. It was observed Ž
y1
. that in llamas during the first 4 min, 11 urethral pulses 3.5 min
occurred randomly, Ž
. but were not associated with body strains. Then, a cluster of contractions
18.5 occurred, which were accompanied of body contractions. Thus, llamas ejaculate 18–19
Ž .
times during 22 min time of copulation Lichtenwalner et al., 1996a . Lamoid semen is highly viscous, which makes handling and estimation of concentra-
tion difficult. The problem may be overcome by using hydrolytic enzymes for liquefac- tion of semen. Trypsin at 1:250 concentration was effective in liquefying alpaca semen.
Trypsin at 1:500 concentration had partially liquefied the semen, and no liquefaction occurred with trypsin at 1:1000 and 1:2000 concentration. The percentage of live
Ž .
spermatozoa was not different for trypsin placed in the collecting tube 61 or added to Ž
. the semen after ejaculation 62.9; Bravo et al., 1997b . In a further attempt to
Ž .
eliminate the viscosity of semen in 2–3 min, collagenase 0.5 mgrml seemed to be a better agent than trypsin. The reaction was irreversible, i.e. the liquefied semen did not
Ž .
regain its viscosity Pacheco, 1996 .
Table 3
a
Ž .
Biochemical components of lamoid and Bactrian camel semen means.e.m.
b
Components Llama adult
Alpaca Lamoid range
Bactrian camel 3 years
6 years Ž
. Chloride mEqrl
40210 34832
40434 263–491
17359 Ž
. Calcium mgrdl
– 181
183 13–31
135 Ž
. Inorganic phosphate mgrdl
10 122
80.4 7–17
131 Ž
. Glucose mgrdl
60.3 70.4
50.3 4–8
1210 Ž
. Fructose mgrdl
40.2 –
60.1 3–7
– Ž
. Lipids mgrdl
1065 8610
9510 51–115
– Ž
. Phospholipids mgrdl
– 291
291 27–31
– Ž
. Total nitrogen mgrdl
62323 54850
64732 398–697
– Ž
. Total protein grdl
40.1 30.3
40.2 3–4
– Ž
. Albumin grdl
– 20.3
20.2 1–3
– Ž
. Globulins grdl
– 10.1
20.2 1–3
–
a
Ž .
Ž .
Adapted from Garnica et al. 1993 and Fuentes 1990 .
b
Ž .
Zhao et al. 1992b .
In alpacas, the volume of ejaculate varies from 0.8 to 3.1 ml and sperm concentration from 82,000 to 250,000rml, with the seminal plasma constituting about 85 of the
ejaculate. Mass motility is not present as it is seen in ram semen. In lamoids, individual motility and percentage of motile spermatozoa in a microscope field range from 69 to
91. However, due to the viscosity of the semen, live spermatozoa appear to oscillate rather than progress in a forward direction. Morphologically, between 70.6 and 84.1
of spermatozoa is normal with 6.7 abnormal heads, 12.3 abnormal tails and 3.8
Ž .
with cytoplasmic droplets Bravo et al., 1997a . The study of Lichtenwalner et al. Ž
. 1996b on seminal characteristics of male llamas revealed 23.7 motile, 39.7 normal
Ž .
and a high proportion 60.3 of abnormal spermatozoa, with abnormal heads account-
Table 4 Mean characteristics of camel semen collected by two methods
Method of collection Characteristic
AV Electroejaculation
Dromedary Bactrian
Dromedary Bactrian
Ž .
Volume ml 7.5
9.7 3.9
6.1
6 y1
Concentration=10 ml 325
465 331
462 Ž .
Motility 51
68 50
69
a
Ž .
Ž . Stained dead sperm
18 14
19 15
b
Ž . Sperm showing morphological abnormalities
28 24
27 24
Ž . Sperm showing acrosome abnormalities
8.5 7.5
8.1 7.7
a
Ž .
Eosin color test Bartmann, 1959 .
b
Ž .
Stained with Karras stain Karras, 1952 .
Ž .
ing for 20.1, followed by abnormal acrosome structure 12.9 and the presence of Ž
. cytoplasmic droplets
11.1 . Most of the biochemical components of semen are comparable to those of other farm animals with the exception of small amounts of
Ž .
Ž .
fructose 4–6 mgrdl and citric acid 4.3 mgrdl which may be due to the absence of Ž
. vesicular glands Garnica et al., 1995 . There is no significant difference regarding the
Ž .
biochemical components between the 3- and 6-year-old alpaca males Table 3 . 6.2. Characteristics of camel semen
Semen of camels is of grey to milky white colour, and as in lamoids, has a viscous consistency immediately after collection. If it is allowed to stand for 10–15 min, it
partially liquefies and the spermatozoa attain motility. Semen used for AI or storage should have at least the characteristics shown in Table 4, as recommended also by
Ž .
Ž .
Ž .
Tingari et al. 1986 , Taha Ismail 1986 and Merkt et al. 1990 .
7. AI and storage of semen
