scholarly journals Development of dominant follicles and length of ovarian cycles in post-partum dairy cows

Reproduction ◽  
1990 ◽  
Vol 88 (2) ◽  
pp. 581-591 ◽  
Author(s):  
J. D. Savio ◽  
M. P. Boland ◽  
J. F. Roche
Author(s):  
Iain J Clarke ◽  
Charlotte B Reed ◽  
Chris R Burke ◽  
Qun Li ◽  
Susanne Meier

Abstract We tested the hypothesis that divergent genetic merit for fertility of dairy cows is due to aberrant reproductive neuroendocrine function. The kisspeptin status of non-pregnant cows of either positive (POS) or negative (NEG) breeding values for fertility was studied in 3 groups (n = 8), based on their previous post-partum period: POS cows which had spontaneous ovarian cycles (POS-CYC) and NEG cows which either cycled (NEG-CYC) or did not cycle (NEG-NONCYC). Ovarian cycles were synchronized, blood samples were taken to define endocrine status and the animals were slaughtered in an artificial follicular phase. The brains and the pituitary glands were collected for quantitative polymerase chain reaction (qPCR) and in situ hybridisation (ISH) of hypothalamic GNRH1, Kiss1, TAC3 and PDYN and pituitary expression of LHB and FSHB. Gonadotropin releasing hormone (GnRH) and kisspeptin levels were quantified in snap frozen median eminentes (ME). GNRH1 expression and GnRH levels in the ME were similar across groups. Kiss1 expression in the preoptic area of the hypothalamus was also similar across groups, but Kiss1 in the arcuate nucleus was almost 2-fold higher in POS-CYC cows than in NEG groups. TAC3 expression was higher in POS-CYC cows. The number of pituitary gonadotropes and the level of expression of LHB and FSHB was similar across groups. We conclude that the lower levels of Kiss1 and TAC3 in NEG cows with low fertility status, and may lead to deficient GnRH and gonadotropin secretion.


2013 ◽  
Vol 41 (05) ◽  
pp. 289-296 ◽  
Author(s):  
K. Seyrek-Intas ◽  
K. Failing ◽  
G. Yilmazbas Mecitoglu ◽  
H. Bostedt ◽  
D. Seyrek-Intas

Summary Objective: To determine the intravascular electrolyte status in dairy cows with respect to age and different courses of parturition to clarify etiological factors influencing peri- or intrapartal imbalances of electrolyte homeostasis. Material and methods: A total of 64 cows at birth were evaluated (primiparous n = 34, pluriparous n = 30). Thirty-three cows showed normal delivery, while 31 cows had a complicated birth. Blood samples were collected intra partum (i. p.) and 2, 4, 6, 8, 12, 16, 24 h post partum (p. p.) as well as [2, 3, 4, 5, 7, 10 days p. p. and levels of total calcium (Catotal), ionized calcium (Caion), inorganic phosphate (Pa), Mg, Na, K, Cl were determined. Results: The results revealed that electrolytes show great fluctuation during and immediately p. p. in relation to age. Already during parturition pluriparous cows had a lower Catotal and Pa concentration compared to primiparous animals. Cows with dystocia exhibited a more intensive and longer lasting decrease of Ca compared to cows with normal birth. In relation to age and severity of birth Pa concentration showed a differing but basically typical course for this electrolyte. Mg, Na, K and Cl concentrations were higher during and immediately after birth compared to p. p. values. Until day 10 p. p. these electrolyte concentrations declined more in older cows with dystocia compared to younger animals. However, the influence of dystocia on concentration of these electrolytes was milder in contrast to Ca and Pa. Conclusions: In summary, primarily older cows are predisposed to imbalances of electrolyte homeostasis intra partum and at the beginning of the lactation. These changes are potentiated in case of complications during parturition. Intravascular Catotal, Caion as well as Pa are most severely affected. Clinical relevance: These results may constitute the basis for a comprehensive metaphylaxis during the peripartal period, especially in cows after dystocia, to positively influence the early convalescence phase.


1996 ◽  
Vol 18 (2) ◽  
pp. 68-75 ◽  
Author(s):  
G. Opsomer ◽  
P. Mijten ◽  
M. Coryn ◽  
A. de Kruif
Keyword(s):  

Reproduction ◽  
2011 ◽  
Vol 141 (3) ◽  
pp. 333-342 ◽  
Author(s):  
Fernando A Rivera ◽  
Luís G D Mendonça ◽  
Gláucio Lopes ◽  
José E P Santos ◽  
Rolando V Perez ◽  
...  

Fertility of lactating dairy cows is associated with reduced progesterone (P4) concentration compared with nonlactating animals. The objective of the current study was to determine whether P4 during growth of the first follicular wave (FFW) affects embryo quality. Lactating Holstein cows at 33±3 days post partum were allocated to one of three treatments. Cows in the FFW and FFW with P4 (FFWP) treatments started the superstimulation protocol on day 1 of the estrous cycle and second follicular wave (SFW) cows started the superstimulation protocol on estrous cycle day 7. Cows were superstimulated with 400 mg of NIH-FSH-P1 (FSH) given twice daily for 5 days, two prostaglandin F2α (PGF2α) injections given with the ninth and tenth injections of FSH, GNRH given 48 h after the first PGF2α injection, and timed insemination 12 and 24 h after the GNRH injection. Cows in the FFWP treatment received two intravaginal P4 inserts during the superstimulation. Embryos were recovered 6.5 days after artificial insemination and excellent/good and fair embryos were frozen and transferred. Blood was sampled daily from estrous cycle day 0 until insemination from donor cows. During the superstimulation protocol, P4 was (P<0.01) greatest for SFW cows followed by FFWP and FFW cows respectively. The percentage of embryos–oocytes from SFW and FFWP cows classified as excellent/good and fair embryos was (P=0.02) greater than those of FFW cows. Pregnancy per embryo transfer was not (P≥0.73) affected by embryo donor treatment. Reduced embryo quality of cows induced to ovulate the follicles from the first follicular wave is a consequence of reduced P4 during follicle growth.


2001 ◽  
Vol 26 (2) ◽  
pp. 495-498 ◽  
Author(s):  
Victoria J. Taylor ◽  
Andrew J. Hattan ◽  
Emma C.L. Bleach ◽  
David E. Beever ◽  
D. Claire Wathes

AbstractThe resumption of reproductive activity in the early post partum period and the subsequent fertility of dairy cows are of considerable practical and economic importance to the producer. Regular milk progesterone analysis was used in this study to monitor the re-establishment of reproductive cyclicity in animals of average (AGM, n=20) and high genetic merit (HGM, n=28) kept under standard management conditions. The profiles obtained were then characterised into normal and four different types of abnormal activity. Resumption of cycles occurred significantly later in the higher yielding cows than in those of average genetic merit (23 ±2.3 days in HGM cows and 15 ± 1.6 days in AGM cows; P=0.0089). There was a significant increase in the amount of abnormal cycles encountered in the high genetic merit animals compared with average yielding animals (61% and 30% respectively; χ2 test, P=0.045); in particular, the delayed occurrence of ovulation post partum (11% vs 0%) and an increased incidence of persistent corpora lutea (32% vs 20%). For high genetic merit animals, the incidence of abnormal cycles was associated with increased peak milkyields (abnormal cycles: peak milk yield 54.7 ± 1.11 kg/day; normal cycles: peak milk yield 46.4 ± 1.35 kg/day, P=0.002). This relationship was not apparent in average genetic merit animals. First service conception rates were 50% (9/18) for AGM cows and 38% (10/26) for HGM cows (χ2 test, n.s.). The calving to conception interval was 98 ± 9.7 days for AGM animals (n=l7) and 105 ± 9.1 days for HGMs (n=24) (t-test, n.s.). In conclusion, this study confirms that high genetic merit dairy cows have compromised reproductive function in terms of a delayed resumption of cyclicity and an increased incidence of abnormal progesterone cycles, which was associated with higher peak milk yields. There was also a reduced first service conception rate in high yielders although the difference was not significant with this group size.


2001 ◽  
Vol 26 (2) ◽  
pp. 313-321 ◽  
Author(s):  
N. H. Gardner ◽  
C. K. Reynolds ◽  
R.H. Phipps ◽  
A.K. Jones ◽  
D.E. Beever

AbstractThe study compared the impact of feeding different energy supplements (barley, molassed sugar beet and fat) prior to calving and the effects of feeding supplemental fat post-partum, on subsequent production and reproductive efficiency of dairy cows. Forty-eight multiparous Holstein-Friesian dairy cows were assigned to one of two groups, six weeks prior to expected calving date and fed a grass based total mixed ration according to ME requirements for late gestation. Group 1 was supplemented with barley (B) or molassed sugar beet feed (SB) prior to calving and was then given a high starch lactation ration. Group 2 was supplemented with either fat (F) or no supplement (C) pre partum, and was then given a similar lactation ration as Group 1 but supplemented with fat. Lactation rations were fed through to week-20 post partum and the cows were monitored during this period. Milk yield (P<0.002) and milkfat (P<0.02) production were higher and milk protein concentration (P<0.001) was lower in Group 2. The number of days to first rise in progesterone following parturition was greater (P<0.01) in Group 2. Due to the design of the study, effects of prepartum supplementation were only evaluated within each lactation ration group. Conception rate to first service was higher (P<0.001) for B than SB supplemented cows in Group 1 and higher (P<0.02) for F than C supplemented cows in Group 2. Services per conception were lower (P=0.06) for B than SB supplemented cows in Group 1 and lower (P<0.05) for F than C supplemented cows in Group 2. Overall pregnancy rates and days open were not significantly different between the groups. The data shows that pre-partum nutrition had an important role in determining subsequent fertility. Despite having negative effects early post partum, supplementing with fat did not affect overall reproductive performance but it did improve milk production.


2001 ◽  
Vol 26 (1) ◽  
pp. 81-91 ◽  
Author(s):  
W.W. Thatcher ◽  
M. Binelli ◽  
D. Arnold ◽  
R. Mattos ◽  
L. Badinga ◽  
...  

AbstractA series of in vitro and in vivo experiments were conducted to characterise the dialogue between embryo and maternal units relative to the mechanisms controlling embryo survival in dairy cattle. Endometrial explants from pregnant cows had an attenuated PGF2α secretory response following treatment with melittin (stimulator of PLA2) and phorbol 12, 13 dibutyrate (PDBu). Thus previous exposure to the conceptus appears to regulate the endometrial synthetic pathway at a point coincident with or distal to PLA2 as well as inhibit PKC or PKC mediated events. Endometrial explants collected from cows receiving intrauterine infusions of rblFN-τ had a reduced secretory response following stimulation with PDBu indicating attenuation in PKC activity. Based upon tyrosine-phosphorylation of STAT-proteins and their translocation to the nucleus after treatment with rbIFN-τ, the JAK-STAT pathway is functional in immortalised bovine endometrial cells (BEND cells). Bend cells, exposed to rblFN-τ, reduced PDBu induction of PGF2α secretion and also decreased protein expression of Cox-2 and PLA. RblFN-τ clearly reduced PKC mediated events leading to an antiluteolytic response in endometrial cells. Feeding diets containing 2.6, 5.2 and 7.8% Menhaden fish meal to lactating dairy cows reduced uterine secretion of PGF2α following sequential injections of oestradiol and oxytocin. Thus antiluteolytic effects in early pregnancy may be amplified by feeding by-pass fats. Pregnancy rate to a timed insemination at first service post-partum is increased in association with injection of bST(500 mg; sc) given at insemination. Furthermore injection of bST at time of insemination in superovulated donor cows increased the number of blastocysts and reduced number of unfertilised embryos. Prospects of integrating novel strategies to improve embryo development and survival into reproductive management systems appear to be attainable in high producing dairy cows.


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