Abstract:
The studies were performed
in the dairy farm from Dancu Research and
Development Station for Cattle Breeding,
Iaşi, Romania, for a period of 5 consecutive
years (2007- 2011), an effective annual
rolled of 450 cows Bălţată cu Negru
Românească (Romanian Black Spotted)
breed.The experimental groups were
composed of cows with anoestrus in 60 days
postpartum interval, diagnosed by rectal
examination with various ovarian disorders:
persistent corpus luteum - group E1-162
cows and luteal cysts- group E2-138 cows.
The treatments according to diagnosis were
applied: PGF2α-,500 mcg/cow- group E1
and Gn-RH, (Receptal, 5 ml/cow-group E2).
In relation to the year in which treatments
were applied some variations in
reproduction indices were found. Regarding
to average intervals from treatment to first
insemination and from treatment to
conception respectively, significant
differences were not found. Regarding to
average conception rates after treatments,
significant differences were found: in
E1group, conception rate at the first
insemination was 30,9% (with annual
variations between 15,0% in 2008 and
41,1% in 2009) (p<0,01); per total
insemination was 64,42 % (with annual
variations between 44,7% - 2011 and
76,9% - 2007) (p<0,001) and pregnancy
index was of 2,4 (with annual variations
between 1,9 - 2009 and 2,8 – 2008); in E2
group, conception rate to first insemination
was 25,96% (with annual variations
between 16,66% - 2011 and 40% - 2010)
(p<0,01); per total insemination was 77,88%
(with annual variation between 52,17% -
2008 and 85,0% - 2010) (p<0,001) and
pregnancy index of 2,4 (with annual
variations between 2,1 - 2007 and 2,6 - 2008
and 2009). In relation to season in which
treatments were applied, we found different
variations in conception rates: in group E1,
the average conception rates at the first
insemination were between 24,24 %
(autumn) and 40,7% (summer) (p<0,05) and
per total inseminations between 75,0%
(spring) and 85,71% (autumn) (p<0,05); in
group E2, the average conception rates at
the first insemination were between 5,3%
(summer) and 48,5% (spring) (p<0,001) and
per total inseminations between 68,4%
(summer) and 81,8% (spring) (p<0,05). We
believe that annual and seasonal variations
found in this work are due to some
deficiencies of management system in dairy farms, such as the stalls prolonged
maintenance and lack of active movement in
the cold season, inadequate microclimate of
shelters, heat stress and deficiencies in
cows feeding , especially those with higher
milk production.
