Proportion of postpartum cows that exhibited cyclic ovarian activities after calving were analyzed using the Categorical Data Modelling.
3. Results
Proportion of cows and intervals at completion of uterine involution for MBE and Ž
. NBE cows were not different P 0.05; Tables 1 and 2 . At 20 and 30 days postpartum,
the proportion of cows having complete uterine involution for cows calving in the dry Ž
. season was greater than those of the rainy season P - 0.05; Table 1 . Cows that calved
in the dry season completed uterine involution by 24.4 days, which was earlier than the Ž
. duration of 26.5 days for cows that calved in the rainy season P - 0.05; Table 2 . It
was observed that for the first 20 days postpartum, the proportion of cows with complete Ž .
uterine involution for the cows with three to five calvings P and cows with one to two
1
Ž .
calvings P groups, were 18.0 and 5.4, respectively, with a difference in favour of
2
Ž .
Ž . the former Table 1 . Cows with three to five calvings P
had completed uterine
1
involution by 24.1 days, which was earlier than the duration of 26.8 days for cows with Ž
. one to two calvings P ; P - 0.05; Table 2 .
2
At 60 days postpartum, the proportion of cows at resumption of ovarian activity for Ž
MBE cows was 25.4, which was greater than the value of 14.7 for NBE cows Table .
1 . Subsequently, by 80 days postpartum, the proportion of cows resuming of postpar- tum luteal activity for the MBE and NBE group were 53.7 and 35.3, respectively
Ž .
Table 1 . Mean interval from parturition to resumption of ovarian activity for MBE Ž
. cows was 71.7 days, earlier than the duration of 77.8 days for NBE cows Table 2 . At
60 days postpartum, the proportion of cows resuming postpartum ovarian activity that Ž
. calved in the dry season 27.7 was greater than cows calving during the rainy season
Table 1 Effect of season of calving, biostimulation and parity on postpartum resumption of cyclic ovarian function
Ž .
Period days postpartum Season of calving
Bull biostimulation Parity
Rainy Dry
MBE NBE
P P
1 2
ns 70 ns65
ns67 ns68
ns61 ns 74
Proportion of cows with uterine inÕolution
a b
b a
10–20 4.5
18.5 9.0
13.2 18.0
5.4
b a
a b
21–30 55.1
44.9 80.6
77.9 75.4
82.4
b a
a b
31–40 11.4
7.7 10.4
8.8 6.6
12.2 Proportion of cows with resumption of oÕarian actiÕity
a b
b a
b b
40–60 12.9
27.7 25.4
14.7 24.6
16.2
b a
b a
61–80 44.3
44.6 53.7
35.3 49.2
40.5
b a
a b
a b
81–100 37.1
20.0 16.4
41.2 21.3
35.1 101–130
5.7 7.7
4.5 8.8
4.9 8.1
a,b
Data in rows within each treatment group with different letter superscripts are significantly different Ž
. P - 0.05 . P : three to five calvings; P : one to two calvings; ns number of cows.
1 2
Table 2 Intervals from calving to manual detection of uterine involution and resumption of cyclic ovarian activity
Ž .
Treatment No. of cows
Interval days from calving to: Uterine involution
Resumption of ovarian activity Biostimulation
a
MBE 67
25.7 71.7
b
NBE 68
25.0 77.8
Ž .
SE 0.6
2.6 Season
b b
Rainy 70
26.5 78.6
a a
Dry 65
24.4 71.3
Ž .
SE 0.6
2.6 Parity
a a
P 61
24.1 65.1
1 b
b
P 74
26.8 71.2
2
Ž .
SE 0.6
2.5
a,b
Ž .
Data within treatment groups with different letter superscripts are significantly different P - 0.05 .
Ž .
12.9; Table 1 . Mean interval from calving to resumption of ovarian activity for cows that calved in the dry season was 71.3 days, which was shorter than for cows that calved
Ž .
in the rainy season 78.6 days; P - 0.05; Table 2 . At 60 and 80 days postpartum, the proportion of cows with resumption of postpartum
Ž . ovarian activity for cows with three to five calvings P
were greater than those cows
1
Ž .
with one to two calvings P ; Table 1 . Mean interval from parturition to resumption of
2
ovarian activity for P cows was 65.1 days, which was earlier than the value of 71.2
1
Ž .
days for P cows P - 0.05; Table 2 . Interactions between biostimulation and parity;
2
Ž .
season and parity were significant P - 0.05 for uterine involution and resumption of ovarian activity. Cows that calved in the dry season that were either P or P resumed
1 2
ovarian activity earlier than cows that calved in the rainy season. Bull-exposed cows
Table 3 Mean liveweight changes and body condition scores from calving to 150 days postpartum
Season of calving n Days postpartum
a
28 56
84 112
150 LiÕeweight changes, kg
Ž .
Ž .
Ž .
Ž .
Ž .
Ž .
Ž .
Dry 65 SE
303.1 8.6 301.7 9.4
303.5 9.1 306.7 8.7
313.1 8.8 317.0 8.9
Ž .
Ž .
Ž .
Ž .
Ž .
Ž .
Ž .
Rainy 70 SE
300.5 7.6 296.8 7.5
294.5 9.6 301.5 7.8
305.8 7.4 310.0 8.1
Body condition scores Ž
. Ž
. Ž
. Ž
. Ž
. Ž
. Ž
. Dry
65 SE 3.6 0.2
3.3 0.1 3.4 0.2
3.8 0.1 4.1 0.1
4.5 0.2 Ž
. Ž
. Ž
. Ž
. Ž
. Ž
. Ž
. Rainy
70 SE 3.5 0.1
3.2 0.1 3.0 0.3
3.4 0.2 3.8 0.2
4.1 0.1
a
Day 0 s day of calving.
with three to five calvings resumed ovarian activity earlier than bull-exposed cows with Ž
. one to two calvings or non-exposed cows that were either P or P
P - 0.05 .
1 2
Mean liveweight changes and body condition scores from calving to 150 days Ž
. postpartum are shown Table 3 . In both seasons, all postpartum cows lost liveweight
and condition for the first 28 to 56 days postpartum. Cows that calved in the dry season, however, regained body weight and body condition from day 56 to day 84 postpartum,
earlier than the cows that calved in the rainy season.
4. Discussion
