Reproductive performance of lactating dairy cows after inducing ovulation using hCG in a five-day progesterone-based fixed-time AI protocol

García-Ispierto, Irina; Rensis, F. De; Casas, Xavier; Caballero, Farouk; Mur-Novales, R.; López‐Gatius, F.

doi:10.1016/j.theriogenology.2017.11.012

Cited by 9 publications

(10 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This meant that about half of the cows had two follicles or more at AI, and the subsequent percentage of double ovulations for all cows was 18.2%. This incidence of double ovulation is within the ranges of 12-30% provided by the different studies following FTAI [6,8,[46][47][48][49][50], or 15-23% for cows following spontaneous estrus [7,8,51,52].…”

Section: Single Versus Double Ovulationsupporting

confidence: 63%

Thermal Mechanisms Preventing or Favoring Multiple Ovulations in Dairy Cattle

Rensis

Morini

García-Ispierto

et al. 2021

Animals

View full text Add to dashboard Cite

While cows are predominantly monovular, over the past 30 years the incidence of multiple ovulations and thus twinning has increased considerably alongside milk production. Multiple pregnancies are not desirable as they negatively affect the health of cows and the herd economy. Although causal mechanisms associated with multiple ovulations have been extensively revised, the process of multiple ovulations is not well understood. Recent studies on the thermal biology of the reproductive system have shown how thermal mechanisms may prevent or favor multiple ovulations. This review focuses on this relationship between thermal dynamics and multiple pregnancies. Cooling of the pre-ovulatory follicle is able to regulate ovulation. In effect, pre-ovulatory local cooling of the female reproductive system favors male and female gamete maturation and promotes fertilization. Thermal stress is proposed here as a model of stress. Periods of high ambient temperature affect the processes of pre-ovulatory follicular cooling and multiple ovulations. While the ratio between unilateral and bilateral multiple pregnancies is normally close to one, under heat stress conditions, this ratio may be 1.4 favoring unilateral multiple pregnancies. A ratio approaching unity is here proposed as an indicator of cow wellbeing.

show abstract

Section: Single Versus Double Ovulationsupporting

confidence: 63%

Thermal Mechanisms Preventing or Favoring Multiple Ovulations in Dairy Cattle

Rensis

Morini

García-Ispierto

et al. 2021

Animals

View full text Add to dashboard Cite

show abstract

“…The absence of luteal structures in these cows suggests that most were anestrous cows. Although the addition of hCG to P4-based protocols has been noted to promote ovulation in anestrous dairy cows [11], anestrous cows are less sensitive to any kind of treatment [8,12]. Hence, a strong positive effect of hCG was recorded in heatstressed cows.…”

Section: Discussionmentioning

confidence: 99%

“…Cows were grouped according to age (primiparous plus secundiparous versus multiparous), milked three times daily and fed complete rations. All cows were artificially inseminated and the herds were subjected to a weekly reproductive health program, as described elsewhere [8,12]. Only healthy cows free of detectable reproductive disorders and free of clinical diseases during the study period (Days −7 to 28 of insemination) were included.…”

Section: Cattle and Herd Managementmentioning

confidence: 99%

“…Inducing ovulation with hCG in protocols for FTAI can promote ovulation in anestrous dairy cows, overcoming the negative effects of HS on the process of ovulation [11]. In a recent study, hCG treatment used to induce ovulation at the end of a P-4-based protocol for FTAI improved follicular/luteal dynamics of both cyclic and non-cyclic dairy cows compared to GnRH treatment [12]. However, although the incidence of ovulation failure in a total of 104 cows receiving hCG (4.8%) was appreciably lower than the rate recorded in a total of 98 cows receiving GnRH (12.5%), this difference was not significant, probably due to the small size of the study population [12].…”

Section: Introductionmentioning

confidence: 99%

“…In a recent study, hCG treatment used to induce ovulation at the end of a P-4-based protocol for FTAI improved follicular/luteal dynamics of both cyclic and non-cyclic dairy cows compared to GnRH treatment [12]. However, although the incidence of ovulation failure in a total of 104 cows receiving hCG (4.8%) was appreciably lower than the rate recorded in a total of 98 cows receiving GnRH (12.5%), this difference was not significant, probably due to the small size of the study population [12]. Therefore, the objective of this study was to compare the effects of inducing ovulation using hCG or GnRH at the end of a 5-day P4-based protocol for FTAI on the incidence of ovulation failure and fertility in anestrous lactating dairy cows under HS conditions.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations