Acknowledgement
This study was supported by 2021 collaborative research program between university and Rural Development Administration, Republic of Korea.
References
- Austin EJ, Mihm M, Ryan MP, Williams DH, Roche JF. 1999. Effect of duration of dominance of the ovulatory follicle on onset of estrus and fertility in heifers. J. Anim. Sci. 77:2219-2226. https://doi.org/10.2527/1999.7782219x
- Beam SW and Butler WR. 1999. Effects of energy balance on follicular development and first ovulation in postpartum dairy cows. J. Reprod. Fertil. Suppl. 54:411-424.
- Bulman DC and Lamming GE. 1977. Cases of prolonged luteal activity in the non-pregnant dairy cow. Vet. Rec. 100:550-552. https://doi.org/10.1136/vr.100.26.550
- Butler WR. 2001. Nutritional effects on resumption of ovarian cyclicity and conception rate in postpartum dairy cows. BSAP Occas. Publ. 26:133-145. https://doi.org/10.1017/S0263967X00033644
- Butler WR. 2003. Energy balance relationships with follicular development, ovulation and fertility in postpartum dairy cows. Livest. Prod. Sci. 83:211-218. https://doi.org/10.1016/S0301-6226(03)00112-X
- Butler WR, Calaman JJ, Beam SW. 1996. Plasma and milk urea nitrogen in relation to pregnancy rate in lactating dairy cattle. J. Anim. Sci. 74:858-865. https://doi.org/10.2527/1996.744858x
- Canfield RW, Sniffen CJ, Butler WR. 1990. Effects of excess degradable protein on postpartum reproduction and energy balance in dairy cattle. J. Dairy Sci. 73:2342-2349. https://doi.org/10.3168/jds.s0022-0302(90)78916-3
- Carroll DJ, Barton BA, Anderson GW, Smith RD. 1988. Influence of protein intake and feeding strategy on reproductive performance of dairy cows. J. Dairy Sci. 71:3470-3781. https://doi.org/10.3168/jds.s0022-0302(88)79953-1
- Ferguson JD, Blanchard T, Galligan DT, Hoshall DC, Chalupa W. 1988. Infertility in dairy cattle fed a high percentage of protein degradable in the rumen. J. Am. Vet. Med. Assoc. 192:659-662.
- Ferguson JD, Galligan DT, Blanchard T, Reeves M. 1993. Serum urea nitrogen and conception rate: the usefulness of test information. J. Dairy Sci. 76:3742-3746. https://doi.org/10.3168/jds.s0022-0302(93)77716-4
- Jolly PD, McDougall S, Fitzpatrick LA, Macmillan KL, Entwistle KW. 1995. Physiological effects of undernutrition on postpartum anoestrus in cows. J. Reprod. Fertil. Suppl. 49:477-492.
- Lamming GE and Darwash AO. 1998. The use of milk progesterone profiles to characterise components of subfertility in milked dairy cows. Anim. Reprod. Sci. 52:175-190. https://doi.org/10.1016/S0378-4320(98)00099-2
- Lucy MC. 2001. Reproductive loss in high-producing dairy cattle: where will it end? J. Dairy Sci. 84:1277-1293. https://doi.org/10.3168/jds.S0022-0302(01)70158-0
- Opsomer G, Coryn M, Deluyker H, de Kruif A. 1998. An analysis of ovarian dysfunction in high yielding dairy cows after calving based on progesterone profiles. Reprod. Domest. Anim. 33:193-204. https://doi.org/10.1111/j.1439-0531.1998.tb01342.x
- Opsomer G, Grohn YT, Hertl J, Coryn M, Deluyker H, de Kruif A. 2000. Risk factors for post partum ovarian dysfunction in high producing dairy cows in Belgium: a field study. Theriogenology 53:841-857. https://doi.org/10.1016/S0093-691X(00)00234-X
- Pankowski JW, Galton DM, Erb HN, Guard CL, Grohn YT. 1995. Use of prostaglandin F2 alpha as a postpartum reproductive management tool for lactating dairy cows. J. Dairy Sci. 78:1477-1488. https://doi.org/10.3168/jds.S0022-0302(95)76770-4
- Park SB, Kim HS, Kim CK, Chung YC, Lee JW, Kim CH. 1997. Relation of conception rate and plasma urea nitrogen in dairy cattle. Korean J. Anim. Reprod. 21:185-189.
- Park SB, Son JK, Park SJ, Baek KS, Jeon BS, Ahn BS, Kim HS, Park CK. 2006. Effect of abnormal ovarian cycle postpartum on subsequent reproductive performance in Holstein cows. Reprod. Dev. Biol. 30:213-218.
- Pelissier CL. 1976. Dairy cattle breeding problems and their consequences. Theriogenology 6:575-583. https://doi.org/10.1016/0093-691X(76)90125-4
- Rajala-Schultz PJ and Grohn YT. 1999. Culling of dairy cows. Part III. Effects of diseases, pregnancy status and milk yield on culling in Finnish Ayrshire cows. Prev. Vet. Med. 41:295-309. https://doi.org/10.1016/S0167-5877(99)00047-1
- Roche JF, Mackey D, Diskin MD. 2000. Reproductive management of postpartum cows. Anim. Reprod. Sci. 60-61:703-712. https://doi.org/10.1016/S0378-4320(00)00107-X
- Rounsaville TR, Oltenacu PA, Milligan RA, Foote RH. 1979. Effects of heat detection, conception rate, and culling policy on reproductive performance in dairy herds. J. Dairy Sci. 62:1435-1442. https://doi.org/10.3168/jds.s0022-0302(79)83442-6
- Shrestha HK, Nakao T, Higaki T, Suzuki T, Akita M. 2004a. Resumption of postpartum ovarian cyclicity in high-producing Holstein cows. Theriogenology 61:637-649. https://doi.org/10.1016/S0093-691X(03)00233-4
- Shrestha HK, Nakao T, Suzuki T, Higaki T, Akita M. 2004b. Effects of abnormal ovarian cycles during pre-service period postpartum on subsequent reproductive performance of high-producing Holstein cows. Theriogenology 61:1559-1571. https://doi.org/10.1016/j.theriogenology.2003.09.007
- Staples CR, Thatcher WW, Clark JH. 1990. Relationship between ovarian activity and energy status during the early postpartum period of high producing dairy cows. J. Dairy Sci. 73:938-947. https://doi.org/10.3168/jds.s0022-0302(90)78750-4
- Villa-Godoy A, Hughes TL, Emery RS, Chapin LT, Fogwell RL. 1988. Association between energy balance and luteal function in lactating dairy cows. J. Dairy Sci. 71:1063-1072. https://doi.org/10.3168/jds.s0022-0302(88)79653-8
- Wiltbank M, Lopez H, Sartori R, Sangsritavong S, Gumen A. 2006. Changes in reproductive physiology of lactating dairy cows due to elevated steroid metabolism. Theriogenology 65:17-29. https://doi.org/10.1016/j.theriogenology.2005.10.003