Agriculture Reference
In-Depth Information
Table 7.4
Least squares means (
±
SE) of physical semen characteristics in Zaraibi bucks as affected
by season of the year.
Traits
Season
Number of
animals
Autumn
10
Winter
9
Spring
8
Summer
8
Mean
SC (cm)
1
25.4
±
±
0.22
c
2 5
±
0.25
c
26.2
±
0.34
b
27.3
±
0.27
a
25.9
±
014
Volume (ml)
0.98
±
±
0.03
a
0.56
±
0.03
c
0.35
±
0.05
d
0.91
±
0.03
b
0.75
±
0.02
Concentration (
×
10
6
/ml)
4,700
±
±
10.1
b
5,288
±
12.7
a
4,903
±
18.4
a
4,783
±
9.9
b
5,072
±
5.48
Total output (
×
10
6
)
4,565
±
15.6
a
3,013
±
19.1
b
1,791
±
28.6
c
4,429
±
15.4
a
3,782
±
9.17
pH
6.69
±
0.03
b
6.68
±
0.03
b
6.79
±
0.04
b
6.79
±
0.03
a
6.72
±
0.01
Gross motility
4.3
±
0.08
a
4.3
±
0.09
a
3.7
±
0.13
b
4.3
±
0.08
4.2
±
0.04
Progressive motility (%)
79.5
±
1.37
a
80.3
±
1.68
a
73.1
±
2.5
b
81.2
±
1.35
a
78.9
±
0.69
Live (%)
82.5
±
0.83
b
77.2
±
1.02
c
76.4
±
1.5
c
87.2
±
0.82
a
81.8
±
0.45
Abnormality (%)
8.8 ± 0.46
c
18.3
±
0.56
a
17.9
±
.84
a
11.4
±
0.46
b
13.5
±
0.29
Semen index ( × 10
6
)
2
3,152 ± 13.2
a
1,982 ± 16.2
b
1,139 ± 24.1
c
3,354 ± 13.0
a
2,630 ± 7.63
a,b,c,d
Within columns, different superscript letters (a-d) are different (
P
<
0.01).
1
SC, scrotal circumference
2
Semen index = semen volume
×
concentration
×
live (%)
×
progressive motility (%)
Source: Barkawi et al., 2006 .
Table 7.5
Correlation coeffi cients of semen characteristics with testicular measurements and live
weight in Rayini goats.
Scrotal circumference
Testis width
Testis length
Live weight
Semen volume
0.85 * * *
0.79 * *
0.51
0.73 * *
Sperm concentration
0.32
0.36
0.54 *
0.35
Percent live sperm
0.13
0.10
−
0.04
0.01
Percent abnormal sperm
−
0.16
−
0.16
−
0.15
0.01
Total sperm number
0.86 * * *
0.83 * * *
0.63 *
0.76 * *
Number of live sperm
0.71 * *
0.66 * *
0.45
0.61 *
Number of live and normal sperm
0.75 * * *
0.72 * *
0.52
0.63 *
*
P
< 0.05
* *
P
< 0.01
* * *
P
< 0.001
Source: Zamiri et al., 2006 .
In general, bucks should be maintained in a good body
condition according to body condition scores (BCS)
throughout the year (3 out of a score of 5). From 2-3 weeks
prior to the mating season, bucks will benefi t from the
supplementary feeding of concentrates (energy) also
known as fl ush feeding (300 g/goat/day). All required
annual vaccinations should be administered at least 6
weeks before the intended breeding season and the hooves
trimmed to facilitate easy walking and mating ability.
During the rainy season, foot dipping to prevent foot rot
is recommended every 3-4 weeks. Dosing for internal
parasites should also be implemented 1-2 weeks prior to
mating. Undoubtedly the most important routine evalua-
tion in bucks to be performed prior to mating is testing for
fertility (semen and scrotal consistency) and sexually
transmitted diseases (brucellosis). These tests are per-
formed preferably within 30 days of the breeding season
(Table 7.5) (Smith, 1980; Gall, 1981; Devendra and Burns,
1983; Bath and De Wet, 2000 ).
