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

Peter, 2009, Postpartum anestrus in dairy cattle, Theriogenology, 71, 1333, 10.1016/j.theriogenology.2008.11.012 Santos, 2016, Aspects and mechanisms of low fertility in anovulatory dairy cows, Anim Reprod, 13, 290, 10.21451/1984-3143-AR870 Roelofs, 2010, When is a cow in estrus? Clinical and practical aspects, Theriogenology, 74, 327, 10.1016/j.theriogenology.2010.02.016 Roelofs, 2015, Estrus detection tools and their applicability in cattle: recent and perspectival situation, Anim Reprod, 2015, 498 López-Gatius, 2003, Is fertility declining in dairy cattle? A retrospective study in northeastern Spain, Theriogenology, 60, 89, 10.1016/S0093-691X(02)01359-6 López-Gatius, 2012, Factors of a noninfectious nature affecting fertility after artificial insemination in lactating dairy cows. A review, Theriogenology, 77, 1029, 10.1016/j.theriogenology.2011.10.014 De Rensis, 2017, Causes of declining fertility in dairy cows during the warm season, Theriogenology, 91, 145, 10.1016/j.theriogenology.2016.12.024 Macmillan, 2010, Recent advances in the synchronization of estrus and ovulation in dairy cows, J Reprod Dev, 56, 42 De Rensis, 2015, Seasonal heat stress: clinical implications and hormone treatments for the fertility of dairy cows, Theriogenology, 84, 659, 10.1016/j.theriogenology.2015.04.021 Garcia-Ispierto, 2013, A five-day progesterone plus eCG-based fixed-time AI protocol improves fertility over spontaneous estrus in high-producing dairy cows under heat stress, J Reprod Dev, 59, 544 Garcia-Ispierto, 2014, Effects of five-day progesterone-based fixed-time AI protocols on folicular/luteal dynamics and fertility in dairy cows, J Reprod Dev, 60, 426 Andreu-Vázquez, 2012, Photoperiod length and the estrus synchronization protocol used before AI affect the twin pregnancy rate in dairy cattle, Theriogenology, 78, 1209, 10.1016/j.theriogenology.2012.05.014 López-Gatius, 2017, The dilemma of twin pregnancies in dairy cattle. A review of practical prospects, Liv Sci, 197, 12, 10.1016/j.livsci.2017.01.001 De Rensis, 2010, Clinical use of human chorionic gonadotrophin in dairy cows: an update, Theriogenology, 73, 1001, 10.1016/j.theriogenology.2009.11.027 De Rensis, 2008, Reproductive performance of dairy cows with ovarian cysts after synchronizing ovulation using GnRH or hCG during the warm or cool period of the year, Theriogenology, 69, 481, 10.1016/j.theriogenology.2007.10.018 De Rensis, 2008, Inducing ovulation with hCG improves the fertility of dairy cows during the warm season, Theriogenology, 69, 1077, 10.1016/j.theriogenology.2008.01.020 García-Ispierto, 2007, Climate factors affecting conception rate of high producing dairy cows in northeastern Spain, Theriogenology, 67, 1379, 10.1016/j.theriogenology.2007.02.009 López-Gatius, 2017, Clinical relevance of pre-ovulatory follicular temperature in heat-stressed lactating dairy cows, Reprod Domest Anim, 52, 10.1111/rda.12916 Hosmer, 1989 Revah, 1996, Prolonged dominance of follicles and reduced viability of bovine oocytes, J Reprod Fertil, 106, 339, 10.1530/jrf.0.1060039 Nation, 2000, Hormonal and ovarian responses to a 5-day progesterone treatment in anoestrous dairy cows in the third week post-partum, Anim Reprod Sci, 63, 13, 10.1016/S0378-4320(00)00164-0 Cerri, 2009, Period of dominance of the ovulatory follicle influences embryo quality in lactating dairy cows, Reproduction, 137, 813, 10.1530/REP-08-0242 Mann, 2007, Corpus luteum size and function following single and double ovulations in non-lactating dairy cows, Theriogenology, 67, 1256, 10.1016/j.theriogenology.2007.01.011 Mann, 2009, Corpus luteum size and plasma progesterone concentration in cows, Anim Reprod Sci, 115, 296, 10.1016/j.anireprosci.2008.11.006 Lukaszewska, 1980, Corpus luteum maintenance during early pregnancy in the cow, J Reprod Fertil, 59, 485, 10.1530/jrf.0.0590485 Mann, 1996, The interrelationship between the maternal hormone environment and the embryo during the early stages of pregnancy, J Reprod Fertil, 17, 55 Mann, 1999, The influence of progesterone during early pregnancy in cattle, Reprod Domest Anim, 34, 269, 10.1111/j.1439-0531.1999.tb01250.x Wiltbank, 2006, Changes in reproductive physiology of lactating dairy cows due to elevated steroid metabolism, Theriogenology, 65, 17, 10.1016/j.theriogenology.2005.10.003 López-Gatius, 2015, Effects of different five-day progesterone-based synchronization protocols on the estrous response and follicular/luteal dynamics in dairy cows, J Reprod Dev, 61, 465