ReviewFactors of a noninfectious nature affecting fertility after artificial insemination in lactating dairy cows. A review
Introduction
Since the beginning of agriculture, cattle among other ruminants have been highly appreciated because they convert vegetable products into highly palatable and nutritious food. In fact, cattle breeding has played an important role in economic development since the Neolithic [1]. The commercial application of cow artificial insemination (AI) is now entering its 80th year and persists as a powerful method of gene dispersal. Artificial insemination has probably been the greatest technological advance in animal breeding. The main reasons for its success have been genetic gain, disease control, and the cost-effectiveness of insemination compared with natural mating [2]. It has also been the most noteworthy example of the successful integration of both research and widespread application [3]. Developments in AI have been sparked by the intensification of milking systems in dairy farms. Artificial insemination offers many advantages and few disadvantages to the dairy farmer, while difficulties in estrus detection limit the use of AI in beef herds. Thus, it has been the dairy industry that has most successfully made use of the technical advances in AI and semen technology [2].
The efficiency of insemination depends among other factors on the deposition of appropriate numbers of normal spermatozoa at the appropriate site in the reproductive tract at the appropriate time of estrus. The metabolic clearance of steroid hormones, such as 17β-estradiol and progesterone [4], pregnancy-associated glycoproteins [5], and the effects of the different types of stress related to high milk production [6] make the high-producing dairy cow a suitable animal model for addressing the factors that affect fertility. This article reviews the factors of a noninfectious nature that affect the fertility of lactating dairy cows in response to AI. The data presented have been mostly obtained by our research group in work conducted on commercial high-producing Holstein-Friesian dairy herds in northeastern Spain. Special attention is paid to factors related to the cow and its environment and to confirming estrus at insemination. The maintenance of pregnancy during the late embryonic/early fetal period is also discussed as a critical step.
Section snippets
Management factors
In the past few decades, infertility has often been linked to the increasing milk yield of high-producing dairy cattle. Milk production and reproductive efficiency are not well correlated genetically [7] and it is difficult to determine which mechanisms are related to the effect of milk production on fertility. Declining fertility has been generally associated with genetic progress and also with the improvements in nutrition and management practices that have led to a continuous increase in
Environmental factors
The impact of environmental conditions on herds of cattle was already noted by ancient civilizations. “On Airs, Waters and Places” documents that Hippocrates in the 5th century BC observed that cattle raised in the near East were more prolific than European cattle because of the temperate climate. The presence of a bull in the herd can positively affect the expression of estrus and therefore the fertility of dairy cattle [21], whereas poor nutrition or the loss of the body reserves (negative
Site of semen deposition
During mating, the bull deposits several billions of spermatozoa into the anterior vagina. However, because the cervix is a major obstacle for sperm transport, the number of spermatozoa that finally reach the uterine body usually does not exceed 1% [38]. In artificial insemination, semen is generally deposited directly into the uterine body, thus bypassing the cervix and permitting the use of a considerably reduced number of sperm [39]. One of the most significant contributions to the
Confirmation of estrus
Man is no match for a bull at detecting estrus in the cow. Incorrect estrus detection is the most common and expensive cause of failure of AI programs. Cows are often falsely identified as being in estrus and inseminated when conception cannot occur [21]. Inseminating the cow is the final, but by no means least important, step in the process of estrus detection. Although professional inseminators palpate the reproductive tract of numerous cows every day, most are not trained to examine the
Pregnancy loss during the late embryonic/early fetal period
Dairy herds are under ever-increasing pressure to improve their efficiency and primary attention is usually directed toward postpartum reproductive disorders and failure to correctly detect estrus. However, it is also of great interest to understand the effects pregnancy loss may have on the reproductive cycle when a cow is pregnant. Records of losses during the early fetal period are not new. Based on monthly records of nonreturn rates, Kidder et al. [60] estimated in 1952 that approximately
Color Doppler ultrasound-based research
The introduction of ultrasonography for use in large farm animals was a technological breakthrough of the 1980s [138]. Nowadays, B-mode ultrasound is common practice in reproductive programs for high-producing dairy herds, especially for pregnancy diagnosis. However, improvements in the equipment used have generated an information cascade. Given the dynamics of changes in ovarian structures, ultrasound examinations are mainly targeted at diagnosing ovarian disorders in nonpregnant cows. The
Conclusions
Fertility in dairy cattle has been declining over the past decades alongside a rise in milk production. The reasons for the decline in fertility are multifactorial and cannot be solely attributed to the increase in milk production. In effect, by improving nutrition and management practices individual milk production can be positively related to high fertility, whereas heat stress, the bull, and inseminator remain as main factors that negatively affect the fertility of a herd. When assessing the
Acknowledgments
The author thanks Ana Burton for assistance with the English translation and Irina Garcia-Ispierto in revising the draft.
References (142)
Artificial insemination: The state of the art
Theriogenology
(2003)Review: dairy cattle reproductive physiology research and management∓past progress and future prospects
J Dairy Sci
(1996)- et al.
Factors affecting retention of early pregnancy in dairy cattle
Anim Reprod Sci
(2004) - et al.
Milk production correlates negatively with plasma levels of pregnancy-associated glycoprotein (PAG) during the early fetal period in high producing dairy cows with live fetuses
Domest Anim Endocrinol
(2007) - et al.
Fertility in the high-producing dairy cow
Liv Prod Sci
(2004) - et al.
Influence of herd environment on health and fertility and their relationship with milk production
J Dairy Sci
(2005) - et al.
Factors affecting the fertility of high producing dairy herds in northeastern Spain
Theriogenology
(2007) Reproductive loss in high-producing dairy cattle: where will it end?
J Dairy Sci
(2001)- et al.
Screening for high fertility in high-producing dairy cows
Theriogenology
(2006) - et al.
Walking activity at estrus and subsequent fertility in dairy cows
Theriogenology
(2005)
Applications of sexed semen in cattle production
Theriogenology
Uterine insemination of heifers with very low numbers of nonfrozen and sexed spermatozoa
Theriogenology
History of commercializing sexed semen for cattle
Theriogenology
In vitro fertilization with flow-cytometrically-sorted bovine sperm
Theriogenology
Insemination of heifers with sexed sperm
Theriogenology
Effect of sex-sorted sperm dosage on conception rates in Holstein heifers and lactating cows
J Dairy Sci
When is a cow in estrus?Clinical and practical aspects
Theriogenology
Effects of body condition score and score change on the reproductive performance of dairy cows: a meta-analysis
Theriogenology
Exposure to a physiologically relevant elevated temperature hastens in vitro maturation in bovine oocytes
J Dairy Sci
Early in vitro fertilization improves development of bovine ova heat stressed during in vitro maturation
J Dairy Sci
Is fertility declining in dairy cattle?A retrospective study in northeastern Spain
Theriogenology
Climate factors affecting conception rate of high producing dairy cows in northeastern Spain
Theriogenology
Site of semen deposition in cattle: a review
Theriogenology
Transport and fate of spermatozoa after insemination of cattle
J Dairy Sci
Increase of pregnancy rate in dairy cattle after preovulatory follicle palpation and deep cornual insemination
Theriogenology
Fertilization rates and embryonic development in superovulated cattle inseminated in different sites within the reproductive tract
Theriogenology
Effect of side of insemination on transuterine transport of spermatozoa in superovulated dairy cattle
Theriogenology
Fertilization rates in superovulating cows after deposition of semen on the infundibulum, near the uterotubal junction or after insemination with high numbers of sperm
Theriogenology
Side of gestation in dairy heifers affects subsequent sperm transport and pregnancy rates after deep insemination into one uterine horn
Theriogenology
Fertilization rates and embryonic death rates in cows bred to bulls of different levels of fertility
J Dairy Sci
A study of 1.000 bovine genitalia
J Dairy Sci
Follicular populations during the estrous cycle in heifersII. Influence of right and left sides and intraovarian effect of the corpus luteum
Anim Reprod Sci
The functional activity of the right and left bovine ovary
J Dairy Sci
Transuterine sperm transport is not affected by bilateral asymmetry of the reproductive system in dairy cows
Theriogenology
Conception in a heifer after deposition of semen in the abdominal cavity
Fertil Steril
Intraperitoneal insemination in repeat-breeder cows: a preliminary report
Theriogenology
Intrafollicular insemination for the treatment of infertility in the dairy cow
Theriogenology
Pregnancy interruption and breeding techniques in the artificial insemination of cows
J Dairy Sci
Comparison of on-farm laboratory milk progesterone assays for identifying errors in detection of estrus and diagnosis of pregnancy
J Dairy Sci
Rheological behavior of the vaginal fluid of dairy cows at estrus
Theriogenology
Importance of inseminating only cows in estrus
Theriogenology
Feeling the ovaries prior to inseminationClinical implications for improving the fertility of the dairy cow
Theriogenology
Conceptus-related measurements during the first trimester of bovine pregnancy
Vet J
Uterine-conceptus interactions and reproductive failure in cattle
Theriogenology
Embryonic death in cattle
Vet Clin Foods Anim
The history of the domestication of cattle
The high-producing dairy cow and its reproductive performance
Reprod Domest Anim
Reproductive health programs for dairy herds: analysis of records for assessment of reproductive performance
Gender preselection in cattle with intracytoplasmically injected, flow cytometrically sorted sperm heads
Biol Reprod
Does heat stress provoke the loss of a continuous layer of cortical granules beneath the plasma membrane during oocyte maturation?
Zygote
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