Reducing the incidence of short estrous cycles in beef cows with norgestomet

Ramírez-Godínez, José Alejandro; Kiracofe, G.H.; McKee, R.M.; Schalles, R.R.; Kittok, R. J.

doi:10.1016/0093-691x(81)90065-0

Cited by 91 publications

(33 citation statements)

References 9 publications

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“…2 (Odde et ai, 1980;Ramirez-Godinez et al, 1981, 1982a. In those studies, >80% of anoestrous cows that showed oestrus within 10 days after weaning of the calves had a short luteal phase after the first oestrus.…”

Section: Resultsmentioning

confidence: 99%

Development of preovulatory follicles expected to form short-lived corpora lutea in beef cows

Bradent¹,

King²,

Odde³

et al. 1989

Reproduction

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Summary. Oestrus, expected to be followed by a short luteal phase, was induced in post-partum cows by weaning their calves at 35 days after parturition. Ovaries containing the first preovulatory follicles (Type F) formed after parturition were collected 3 h after the onset of oestrus. For comparison, preovulatory follicles (Type C) were collected 3 h after the onset of oestrus in normally cycling cows. The number of granulosa cells was determined and the concentrations of receptors for follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in granulosa cells and for LH in theca cells were measured. Concentrations of oestradiol-17\g=b\,testosterone, androstenedione and progesterone in follicular fluid were also measured. Type F follicles contained about twice the number of granulosa cells (based on DNA) as did Type C follicles (45\m=.\8\m=+-\ 1 1 \ m= . \ 3 and 24\m=.\5 \ m=+-\ 3\m=.\9 \g=m\gDNA/follicle, respectively; P < 0\m=.\05) but these cells had fewer receptors for LH (0\m=.\13\ m=+-\0\m=.\02vs 0\m=.\29\ m=+-\ 0\m=.\03fmol/\g=m\g DNA; P < 0\m=.\01) and FSH (0\m=.\61\ m=+-\0\m=.\08vs 1\m=.\3\ m=+-\0\m=.\29fmol/\g=m\gDNA; P < 0\m=.\08) than did those from Type C follicles. Additionally, there were fewer receptors for LH in theca tissue from Type F than from Type C follicles (28\m=.\3 \m=+-\5\m=.\2vs 51\m=.\3\ m=+-\6\m=.\1 fmol/follicle; P < 0\m=.\01). Concentrations of oestradiol-17\g=b\(475\m=.\8\ m=+-\ 85\m=.\6vs 112\m=.\9\ m=+-\ 40\m=.\0 ng/ml; P < 0\m=.\01) and androstenedione (214\m=.\1 \m=+-\48\m=.\7vs 24\m=.\7 \ m=+-\7\m=.\7ng/ml; P < 0\m=.\01) in follicular fluid were higher in Type C than in Type F follicles. There were therefore more granulosa cells in Type F follicles which contained fewer receptors for LH and FSH and accumulated less oestradiol-17\g=b\ in the follicular fluid. We suggest that the characteristics of preovulatory follicles may influence the life-span of the subsequently formed corpus luteum and short luteal phases may de due, in part, to altered follicular development.

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Section: Resultsmentioning

confidence: 99%

Development of preovulatory follicles expected to form short-lived corpora lutea in beef cows

Bradent¹,

King²,

Odde³

et al. 1989

Reproduction

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“…Oxytocin injected (Troxel et al, 1984) or released in response to milking or suckling or the presence of uterine infection (Roberts et al, 1975 ;Lindell et al, 1982 ;Watson, 1984) may be responsible for an increased concentration of PGFM and consequently earlier luteolysis and earlier resumption of a normal luteal phase (Madej et al, 1984). It has also been shown that intrauterine infusion of indomethacin, an inhibitor of prostaglandins synthesis, not only diminishes basal or induced concentrations of oxytocin and of the PGF metabolite (Troxel et al, 1984) but also prolongs the life of corpora lutea induced by GnRH (Troxel and Kesler, 1984a (Troxel and Kesler, 1984c) have beneficial effects on the amount of progesterone secreted by the corpora lutea thus induced (Ramirez-Godinez et al, 1981 ;Sheffel et al, 1982 ;. Such pretreatment is without effect if applied 40 days after calving .…”

Section: Progesteronementioning

confidence: 99%

Endocrine regulation of postpartum ovarian activity in cattle : a review

Hanzen

1986

Reprod. Nutr. Dévelop.

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Summary. The Clinically, the postpartum period is characterized by a period of behavioural anoestrus, the duration of which differs in different breeds.If the detection of oestrus is optimal, anoestrus lasts for 20 to 70 days in dairy cows Callahan et al., 1971 ;Schams et al., 1978 ;Pirchner et al., 1983 ;Richardson et al., 1983 ;Etherington et al., 1984). This period is highly variable in suckled cows and lasts from 30 to 110 days (Wiltbank and Cook 1958 ;Oxenreider 1968 ;Graves et al., 1968 ;Casida et al., 1968 ; Nancarrow et al., 1977 ;Holness et al., 1978 ;Wettemann et a/., 1978 ;Short et al., 1979 ;Dunn and Kaltenbach, 1980 ;Kesler et al., 1980 ;Randel, 1981 ;Montgomery, 1982 ;Peters and Riley, 1982 . Jainudeen et al., 1982Bastidas et al., 1984 ;King and Mc Leod, 1983Leod, /1984Hansen and Hauser, 1984 ;Montgomery et al., 1985).Assay of progesterone in plasma or milk has shown that 88 % of animals of dairy breeds have an luteal activity present by 35 days after calving (Ball and Lamming, 1983) and 95 % within 50 days (Bulman and Lamming, 1978). According to different authors, the first rise of progesterone appears between 16 and 69 days after calving in dairy cows (Webb et al., 1977(Webb et al., , 1980Pirchner et al., 1983) and between 56 and 96 days in suckled cows (Fonseca et al., 1980 ;Peters and Riley 1982 ; Jainudeen et al., 1982 Jainudeen et al., /1983Montgomery et al., 1985).It is possible to detect ovarian follicles by rectal palpation in both milked and suckled cow from the second week after calving (Saiduddin et al., 1968 ;Callahan et al., 1971 ;Kesler et al., 1979 ;Webb et al., 1980 ;Kesler et al., 1980 ;Stevenson et al., 1983 (Wiltbank et al., 1962(Wiltbank et al., , 1964Dunn et al., 1969 ; Lammond, 1970 ;Corah et al., 1975 ;Whitman et a/., 1975 ;Duffour, 1975 ;Holness et al., 1978 ;Carstairs et al., 1980 ;Dunn and Kaltenbach, 1980 ; Gauthier and Thimonnier, 1982 ;Peters and Riley, 1982 ; Mc Leod, 1983/1984 ;Rutter and Randel, 1984). Some authors have found that overfeeding improves ovarian (Wiltbank et al., 1962(Wiltbank et al., , 1964Hansen et al., 1982) or pituitary (Beal et al., 1978 ;Jordan and Swanson, 1979 ;Lishman et al., 1979 ;Moss et al., 1982) function. Others have found no relation between feeding and the ovarian (Lishman et al., 1979 ;Carstairs et al., 1980) or pituitary (Hill et a/., 1970 ;Dunn et al., 1974 ;Spitzer et al., 1978 ;Haresign, 1981 ;Rutter and Randel, 1984) activity.Little is known about the mechanism under which diet exerts its effect. It is conceivable that feeding influences the ovarian response to gonadotropins (Gombe and Hansel, 1973). There was a positive correlation between the degree of fatness of an animal and the plasma concentration of 17 !3-oestradiol, 7 weeks after calving (Lishman et al., 1979).Feeding affects the release of luteinizing hormone (LHI and subsequent luteal function Spitzer et al., 1975 ;Apgar et al., 1975 ;Beal et al., 1978). It has been observed that the release of LH induced by gonadotropin releasing hormone (GnRH) injection was grea...

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“…19'76;Flood et al 1919). Subsequent to the initial short elevation in blood Po, animals frequently exhibit normal estrus, ovulatory cycles and fertility (King et al 1976;Ramirez-Godinez et al 1981).…”

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confidence: 99%

Endocrine Profiles and Functional Characteristics of Corpora Lutea Following Onset of Postpartum Ovarian Activity in Beef Cows

Manns¹,

Humphrey²,

Flood³

et al. 1983

Can. J. Anim. Sci.

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Luteal cell types were evaluated, percent of area covered by large cells was de-termined and average luteal cell diameter was calculated. In exp. 3, seven cows were bled daily from parturition until day 25 postpartum. Serum from all experiments was assayed for progesterone (Po), FSH, LH and a prostaglandin metabolite (PGFM). The data showed that serum PGFM levels declined from a peak at calving to basal levels by 10 days postpartum which was well before the first ovulation.In all instances the observed peaks of serum LH and serum FSH preceded the first rise in P, which, in eight of nine cases, was due to a functional CL. These CL were functional for periods of time ranging from 3 to 12 days. The regression of short-lived CL appeared abnormal compared to the longer-lived CL in which regression was characterized by a rapid decline in P* and elevated blood PGFM. These data show clearly that the first increase in Po is preceded by a typical LH surge, followed by ovulation and CL formation which has a variable life-span.

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Reducing the incidence of short estrous cycles in beef cows with norgestomet

Cited by 91 publications

References 9 publications

Development of preovulatory follicles expected to form short-lived corpora lutea in beef cows

Development of preovulatory follicles expected to form short-lived corpora lutea in beef cows

Endocrine regulation of postpartum ovarian activity in cattle : a review

Endocrine Profiles and Functional Characteristics of Corpora Lutea Following Onset of Postpartum Ovarian Activity in Beef Cows

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