scholarly journals Effects of insemination timing and GnRH treatment on pregnancy rates of N’Dama cattle after estrus induction with progestin

Author(s):  
Marcel W.M. Okouyi ◽  
Christian Hanzen

Le but de cet essai clinique a été de quantifier les pourcen­tages de gestation de bovins N’Dama (n = 168) trypanotolé­rants après traitement avec un dispositif intravaginal libérant de la progestérone (CIDR ; 1,38 g de progestérone) inséré pen­dant sept jours. Une injection intramusculaire (IM) de prosta­glandine (500 μg de cloprostenol) a été administrée deux jours avant le retrait du dispositif. Par la suite, une injection IM de 400 UI de gonadotrophine chorionique équine (eCG) a été administrée lorsque le dispositif a été retiré. Les animaux ont été inséminés 48 (groupe 1) et 72 heures (groupe 2) après le retrait du CIDR. Dans les deux groupes, la moitié des animaux ont été traités avec 4,2 μg d’acétate de buséréline et l’autre moitié avec 1 ml de sérum physiologique. Quatre protocoles ont ainsi été testés : CIDR-PG-eCG/IA48h, CIDR-PG-eCG/ IA48h/GnRH+, CIDR-PG-eCG/IA72h et CIDR-PG-eCG/IA72h/ GnRH+. Un diagnostic de gestation a été réalisé par échogra­phie 45 à 60 jours après l’insémination. Le pourcentage de gestation moyen a été de 37,5 %. Celui des vaches adultes (43,2 %, n = 111) a été significativement (p < 0,03) plus élevé que celui des génisses (26,3 %, n = 57). Le pourcentage de gestation a été significativement plus élevé (p < 0,002) chez les animaux du groupe 2 (48,8 %) que chez ceux du groupe 1 (26,2 %). L’état physiologique et l’injection de GnRH au moment de l’insémination n’ont pas eu d’impact significatif sur le pourcentage de gestation. Le protocole hormonal utili­sant CIDR-PG-eCG (400 UI) et une insémination systématique 72 heures après ont amélioré les pourcentages de gestation chez la femelle N’Dama.

Author(s):  
Stephanie J. Ventura ◽  
William D. Mosher ◽  
Sally C. Curtin ◽  
Joyce C. Abma ◽  
Stanley Henshaw

2010 ◽  
Vol 40 (6) ◽  
pp. 39
Author(s):  
SHARON WORCESTER
Keyword(s):  

2018 ◽  
Vol 52 (1-4) ◽  
pp. 22-30
Author(s):  
A K Paul ◽  
S M T Rahman

Hormonal treatment of cows at the coastal region of Barisal district of Bangladesh was performed to assess the improvement of pregnancy rate. A total of 100 cows and heifers with irregular history of cyclicity were selected randomly and divided into five treatment groups. The groups were A (treated with anthelmintic), B (treated with anthelmintic, vitamin ADE and multivitamin powder), C (treated with PGF2α), D (treated with GnRH) and E (treated with GnRH and PGF2α). Each group comprised of 20 animals. The age, breed and parity of experimental cows were considered during treatment. In the study, the cows treated with both GnRH and PGF2α (group E) showed significantly (p<0.05) higher estrus (80%) and pregnancy rate (60%) than that of group A, B, C and D. The overall estrus rates of local and crossbred cows were 64% and 70%, respectively and the pregnancy rates were 40 and 52%, respectively. The crossbred cows responded significantly (p<0.05) to hormonal treatment than that of local cows. Parity-2 cows showed higher estrus sign than that of other parities. However, the pregnancy rates were higher significantly (p<0.05) in parity-2 and parity ≥4 cows than that of parity-0, parity-1 and parity-3 cows. The pregnancy rate was also found higher in case of 4 to <5 years old cows than that of 2 to <3, 3 to <4, 5 to <6, and ≥6 years old. It may conclude that the hormonal regimen increases the pregnancy rate as well as decreases the undesired waiting of estrus and conception. Further study with more sample size will reveal the more effective treatment for cows at the coastal areas of Bangladesh.


2018 ◽  
Vol 52 (1-4) ◽  
pp. 22-30
Author(s):  
A K Paul ◽  
S M T Rahman

Hormonal treatment of cows at the coastal region of Barisal district of Bangladesh was performed to assess the improvement of pregnancy rate. A total of 100 cows and heifers with irregular history of cyclicity were selected randomly and divided into five treatment groups. The groups were A (treated with anthelmintic), B (treated with anthelmintic, vitamin ADE and multivitamin powder), C (treated with PGF2α), D (treated with GnRH) and E (treated with GnRH and PGF2α). Each group comprised of 20 animals. The age, breed and parity of experimental cows were considered during treatment. In the study, the cows treated with both GnRH and PGF2α (group E) showed significantly (p<0.05) higher estrus (80%) and pregnancy rate (60%) than that of group A, B, C and D. The overall estrus rates of local and crossbred cows were 64% and 70%, respectively and the pregnancy rates were 40 and 52%, respectively. The crossbred cows responded significantly (p<0.05) to hormonal treatment than that of local cows. Parity-2 cows showed higher estrus sign than that of other parities. However, the pregnancy rates were higher significantly (p<0.05) in parity-2 and parity ≥4 cows than that of parity-0, parity-1 and parity-3 cows. The pregnancy rate was also found higher in case of 4 to <5 years old cows than that of 2 to <3, 3 to <4, 5 to <6, and ≥6 years old. It may conclude that the hormonal regimen increases the pregnancy rate as well as decreases the undesired waiting of estrus and conception. Further study with more sample size will reveal the more effective treatment for cows at the coastal areas of Bangladesh.


1972 ◽  
Vol 70 (2) ◽  
pp. 385-395 ◽  
Author(s):  
B. K. Davis ◽  
I. Noske ◽  
M. C. Chang

ABSTRACT Mature female hamsters bearing subcutaneous polyacrylamide (PAA) implants, with ethinyloestradiol (EO), for at least 10 days prior to mating revealed: 0.5 and 2.5 mg EO in 7% PAA significantly disturb the timing of oestrus and mating, but have no apparent effect on rate of pregnancy, ovulation and implantation. 2.5 mg EO in 20 and 40% PAA conspicuously reduces the likelihood of pregnancy, although the occurrence of oestrus and mating are affected only slightly. Fertility in these hamsters was virtually restored, judging from pregnancy rates, when they were remated 11 days, or more, following removal of their implants (37 days after implantation), but significantly more foetuses were resorbed in these litters. From tissue sections of skin and muscle at the implant site, ovary, uterus, pituitary, adrenals and liver, PAA implants, without EO, cause no overt pathological changes in the bearer. Effects characteristic of oestrogen are present when these implants contain EO, and these include a conspicuous thickening of the epidermis and dermis; haemorrhagic lesions were also noted in the maternal placenta of animals with EO implants. There is an association between reproductive performance and the rate of EO release by an implant. A 7% PAA implant with 2.5 mg EO can release most of it within 2 days, and principally influences events (oestrus and mating) that precede the main target (pregnancy) of a 20% PAA implant, which releases the steroid over the longer interval of 7 days.


2015 ◽  
Vol 4 (1) ◽  
pp. 356-362
Author(s):  
Josemara Silva Santos ◽  
Tania Cavalcante ◽  
Francisca Elda Ferreira Dias ◽  
Domenica Palomaris Mariano de Souza ◽  
Alencariano J.S. Falcão ◽  
...  

The objective of the experiment was to evaluate the effects of recombinant bovine somatropin (rbST), and the reuse of the progesterone (P4) releasing devices in resynchronization, on the pregnancy rates of Nellore cows submitted to fixed-time artificial insemination. A group of 123 multiparae Nellore cows, was submitted to a resynchronization protocol: on day 0 a Bovine Intravaginal Device (DIB® ) with 1,0g of P4 was implanted, associated with intramuscular administration of 2,0mg of estradiol benzoate (IM); on day 8 DIB was removed; and 1,0mg of estradiol cypionate, 0,15mg of prostaglandin F2? and 300 UI of equine chorionic gonadotropin were administered; on day 10, fixed-time artificial insemination was conducted (FTAI). The cows were randomized into G1 (n=12) – without rbST / with used Bovine Intravaginal Device, G2 (n=50) – without rbST / with new DIB, G3 (n=11) - with rbST / with used DIB and G4 (n=50) – with rbST/ with new DIB. rbST was introduced on the eighth day of the protocol. Sixty days after TAI, pregnancy diagnoses were conducted, via rectal palpation. Blood samples were taken on day 0, 8 and 10 of the protocol, in order to assess P4 plasma concentrations. Pregnancy rates were statistically evaluated through Generalized Linear Models Theory and their significance was tested with Analysis of Deviance. Pregnancy rates were 58%, 40%, 81% and 48% for G1, G2, G3 and G4, respectively, with significant statistical difference for G3. Plasma concentrations of P4 were not statistically different among groups, or collections. In view of the results obtained, we concluded that the administration of rbST in association with P4 DIB, used for the third time, improves pregnancy rates. Estrus resynchronization and re-insemination positively impacted pregnancy rates.


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