Buffalo Follicular Dynamics

2,003 views

Published on

Buffalo Follicular Dynamics

Buffalo Follicular Dynamics

  1. 1. Buffalo follicular dynamics: Basic & applied concepts RK Sharma, SK Phulia, Jerome A, AK Balhara & Inderjeet Singh (c) JEROME A
  2. 2. Ovarian follicular dynamicsFollicular dynamics cattle (Ginther et al. 1989), buffaloes (Tanejaet al. 1996)Numerous work on follicular dynamics of buffalo.(Baruselli et al.1997; Singh et al.2000; Manik et al.2002; Ali etal.2003; Presicce et al.2005; Azawi et al.2009; Yindee etal.2011; Sharma et al. 2012)Follicular growth in buffalo occurs in a wave-like pattern.A follicular wave involves synchronous growth of a group offollicles in both ovaries, from which one follicle attains dominanceover others to become the dominant follicleFollicles failing to ovulate – undergo atresia (c) JEROME A
  3. 3. Follicle development stages:Recruitment, Selection, Growth, Dominance, Regression &atresia Dominance Regression Growth Selection NextRecruitment Recruitment Usually 2 to 3 follicular waves occur during the estrous cycle in buffaloes (c) JEROME A
  4. 4. Endocrinology of the Estrous Cycle w.r.t follicular dynamicsBasic endocrine mechanism leading to the occurrence of thewave pattern - similar between cattle and buffalo in terms offollicular dynamicsIn buffalo that a transient rise in serum concentrations ofFSH begins each follicular wave (Presicce et al. 2003)Decreased episodic secretion of LH is associated with loss ofdominance and with the end of a non-ovulatory follicular wave.Several intra-follicular growth factors: endocrine, autocrineor paracrine actions that modify gonadotropin stimulatedfollicular growth and differentiation (c) JEROME A
  5. 5. Hormones controlling follicular development FSH, LH, Estrogen, Progesterone (Direct) PG (Indirect)Other intra-follicular factors IGF-1, BMP1 EGF, FGF, PDGF , IGF (including IGF-binding protein) TGFβ - (inhibin & activin) HGF - (cytokines) (Bruno et al.2009) (c) JEROME A
  6. 6. BUFFALO FOLLICULAR DYNAMICS (c) JEROME A
  7. 7. Fetal periodDuring fetal development, germinal cells is formed in a series of stagessuch as migration of primordial germinative cells to the gonadal ridge,(proliferation and initiation of prophase I, blocking at diplotene stage, andfinally, the formation of primordial follicles)Transition in morphological features of follicles, - presence of oogones andprimordial follicles from 0 to 3 months of pregnancy, followed by preantralfollicles (primary and secondary follicles) between 4 to 6 months, andpreantral follicles and in some cases, antral follicles from 7th month to theend of pregnancy (Carvalho et al. 2007) (c) JEROME A
  8. 8. Increasing fetal age: Marked decrease in the proportion of primordial andprimary follicles, and a concomitant increase in secondary follicles.Mean number of follicles isolated at different stages of development, andat different fetal ages is generally characterized by considerableindividual variation (Santos et al.2006)Buffalo primordial follicles: 10,000–20,000 compared with over 100,000 incattle (Danell, 1987) (c) JEROME A
  9. 9. Pre-pubertal periodFollicular development in prepubertal buffalo heifers, crucial to initiationof puberty that is often delayed in the species (Cockrill, 1980), has notbeen studied in detail.Delayed puberty leads to higher age at first calving and lower life-timemilk production and net calf crop.CIRB studies suggest that follicular growth in prepubertal buffalo heifersoccurs in a wave-like pattern. (Sharma et al. 2010, 2012)The largest DF of each wave attains a diameter of 7-11 mm andsubsequently undergoes atresia without ovulation. The regression of DF isfollowed by emergence of a new follicular wave. (c) JEROME A
  10. 10. Studies revealed growing dominant follicles respond to exogenousGnRH either with atresia, ovulation or formation of luteinized follicles.GnRH induced corpus luteum is smaller and short-lived and theseheifers failed to resume ovarian cyclicity following CL regression.These findings suggest that although the pituitary of prepubertalbuffalo heifers is responsive to exogenous GnRH, the H-P-O axisremains immature and does not maintain cyclicity. (c) JEROME A
  11. 11. PubertyPuberty when they reach about 55–60% of their adult bodyweight, but the age at puberty widely ranges from 18 to 46months (Jainudeen and Hafez, 1993) and body weight of 250 to400 kg for river buffaloes,Influenced by factors: genotype, nutrition, management, climate,year or season of birth and diseases.As puberty approaches, the growth rate and maximum size ofdominant follicle increases until a sufficient size (Sharma et al. 2010)Circulating estradiol to produce LH surge and ovulation areachieved. As puberty approaches, continued estradiol becomesless inhibitory to LH pulses and circulating LH rises. (c) JEROME A
  12. 12. On puberty, the number of estradiol receptors in hypothalamusdecreases, resulting in a possible decrease in negative feedbackof estradiol on release of LH pulses (Adams et al. 1994)The subsequent increase in frequency of LH pulses allows thedominant follicle to grow to ovulatory size and produce enoughestradiol to induce an LH surge and ovulation.buffalo heifers do experience follicular development in wavelike pattern, but largest dominant follicle size and its growthrate remain lower than in adult buffaloes. (c) JEROME A
  13. 13. POST PUBERTYOvarian follicular growth during the estrous cycle in buffalo - similar tocattle, characterized by primarily two and less commonly three-waves offollicular recruitment, growth and regression. (Taneja , 1996)Buffaloes have estrous cycles with 1-wave (3.3%), 2-waves (63.3%) or 3waves (33.3%) of follicular growthThe first wave begins on day 1, the second around day 9-11 while the thirdwave appears on day 17 of the estrous cycle.Only the DF of the final wave ovulates, whereas the DFs of the precedingwaves undergo atresia.The wave-like pattern of ovarian follicular growth continues even duringanoestrus period and diameter of the largest DF may attain a sizeequivalent to that of the pre-ovulatory follicle . (Manik et al. 2002) (c) JEROME A
  14. 14. Number of follicular waves per cycle and their characteristics have beenreported in buffalo from different countries.In Brazil, Baruselli et al. (1997) showed that the number of follicular wavesduring an estrous cycle was one in 3% of animals, two in 63% and three in33%.A study on Egyptian buffalo, however, indicated the majority of estrouscycles (54%) had three waves of follicular development (Barkawi et al. 2009). A study on suckled Thai swamp buffalo has shown that the first postpartumovulation was followed by a short estrous cycle (10.2±0.38 days) in 84% ofthe animals, but the prevalence of these decreased thereafter.The mean diameters of ovulatory follicles increased between the first andsecond ovulation (13.50±0.52–14.31±0.38 mm). (Yindee et al. 2010) (c) JEROME A
  15. 15. CIRB studies revealed the incidence of two and three wave cycles intwo-third and one-third proportion, respectively, of adult buffaloes.The first wave usually commences on day 1 (day 0 = ovulation), while thesecond wave emerges earlier in buffaloes with three wave cycles. Thethird wave emerges on day 16.8 in the latter group.The estrous cycles with two and three follicular waves of folliculardevelopment differed in the mean length of the luteal phase (10.4compared to 12.7 days) and the interval between ovulations (22.3compared to 24.5 days).Our studies in cyclic Murrah buffaloes during summer season indicatedthat there was a predominance of 2 wave compared to 3 wave cycles withthe diameter of the ovulatory DF at estrus being 14.32±0.43 mm. (Sharma et al. 2009) (c) JEROME A
  16. 16. The anovulatory DF also attained maximum diameter of 13.46±0.58 mm on day11.14±0.96 of the cycle. In three wave buffaloes, the average durations of thefirst, second and the ovulatory waves were 23.14±1.14, 13.0±1.0 and 12.85±1.06days, respectively.Buffaloes with two-waves of follicular development during estrous cycles, thegrowth rate and diameter of the largest follicle are significantly smaller inheifers than cows. (Sharma et al. 2009) (c) JEROME A
  17. 17. AnoestrusContinuous waves of follicular growthIn each wave a variable number of small sized follicles emergedtogether, one of which subsequently developed to a size of 7.1-19.2 mm indiameter.Remaining follicles in the wave ceased to grow further and startedregressing.Largest DF fails to ovulate and undergo atresiaMean maximum diameter of dominant follicle (DF) was 12.52±0.22 mm andthat of SF was 7.58±0.19 mm. This DF diameter: comparable to DFdiameter of ovulatory follicles.The growth phase and regression phase duration of DF did not differsignificantly. (10.96±0.41 and 10.64±0.29 days). (c) JEROME A (Sharma et al. 2009)
  18. 18. The wave persisted for a period of 21.18±0.53 days, whereasaverage duration of subordinate follicle (SF) was 9.86±0.36 daysIn anoestrus buffaloes, the DF undergoes atresia rather thanovulation, possibly due to failure of appropriate pre-ovulatory LHsurge..This study revealed that the anestrus condition is due to failureof the DF to ovulate rather than failure in folliculardevelopment.Anoestrus condition is due to failure of DF to ovulate ratherthan to their absence (Savio et al. 1990)Insufficient release of LH from the pituitary (Roche et al. 2000) (c) JEROME A
  19. 19. Effect of Superovulation on follicular dynamicsSuperovulation associated with embryo-recovery and embryo-transfer tosynchronized recipient females is considered an effective means ofincreasing the contribution of high quality females to the gene pool of thepopulation.Superovulatory effect of PMSG and FSH have been used to increaseovulation rates in buffaloes and have been applied in conjunction withprogestagen and/or prostaglandin F2α treatments to regulate the oestruscycle.superovulation by 3000 IU of PMSG in buffaloes, rapidly induced LH surgesof low magnitude, causing unovulated follicles to become endocrinologicallyactive (Shallenberger et al. 1990)FSH reported as effective as the multiple dose regimen (Kasiraj et al.1992) or to produce a lower superovulatory response compared to a multipleinjection regimen (Misra, 1997) (c) JEROME A
  20. 20. Buffalo- poor superovulatory response: poor follicular response toexogenous gonadotrophins, inherent endocrine patterns as well as to thecharacteristics of the follicular population and ovarian folliculogenesis.Nine to 14 ovulatory size follicles were consistently observed inbuffaloes stimulated with FSH (Baruselli et al. 1999). ovulation rates of62.8 percent, a value similar to that found in cattle (Desaulniers et al.1995; Shaw et al. 1995; Stock et al. 1996)Number of ovulations presented a high correlation (0.86) with thenumber of corpora lutea found on the day of embryo collection, but onlyone to three ova/embryos were recovered (average recovery rate/CL =30 percent) (c) JEROME A
  21. 21. Increase in the number of ovulations has been reported whensuperstimulatory treatments were initiated in the absence of adominant follicle or when the dominant follicle was in a regressing orplateau phase (Taneja et al. 1995).Low number of embryos: failure of oocytes to enter the fallopiantubes and/or impaired transport of ova/embryos (c) JEROME A
  22. 22. Research at CIRBIn superovulated buffaloes, follicles of over 10 mm diameter may ovulatefollowing FSH treatment as the preparation does contain some LHcontamination.This mid cycle ovulation is not desirable as this new CL does not respondto PG and continues to grow at the time of expected SOV heat – disturbshormonal synchrony, ovulation, fertilization, embryo development.Ovulatory response: low, CL developed following SOV treatment were ofshort duration and showed regression by day 10 of superovulatory cycle.Synchronize the superovulatory treatment with the emergence of a newfollicular wave via ultrasound guided DF aspiration / ablation wasattempted prior to initiation of superovulatory treatment.With ablation, improved results were obtained vis-à-vis mean number offollicles greater than 9 mm at AI as well as greater mean number of CLsand viable embryo recovery (Sharma et al. 2011) (c) JEROME A
  23. 23. Hormonally intervened cycleFollicular dynamics changes according to the hormonaltreatmentSynchronization of oestrus with Ovsynch protocol resulted in Mostovulations were synchronized and recorded at AI and the following day innulliparous (24/30; 80%) and pluriparous (12/14; 85.7%) buffaloesrespectively.A follicle shift was recorded in 14 of 30 (46.6%) and 11 of 14 (78.5%) innulliparous and pluriparous buffaloes respectively .Pregnancy rate following Ovsynch protocol was 40% (12/30) and 42.8%(6/14) in nulliparous and pluriparous buffaloes respectively. (c) JEROME A
  24. 24. PRID-PMSG protocol: Majority of ovulations were synchronized andrecorded at first, second AI and following day (76.4%). A follicleshift occurred in 88.2% animals and among the 12 recordedpregnancies, 11 derived from follicle shift (91.6%). Pregnancy rate:70.5% .Progestagen treatment on acyclic buffaloes resulted in significantlyhigher pregnancy rate compared with Ovsynch protocol Presicce et al. 2005 (c) JEROME A
  25. 25. Gnrh TreatemntPost GnRh treatment ovarian dominant follicle became persistent in allfemales given 100 µg ovulated within 48 h, subsequent with an emergenceof a new follicular wave - 100 µg of Gonadorelin seems to be the mosteffective dose to induce ovulation followed by an emergence of anew follicular wave in river buffalo Rastegarnia et al. 2004Replacing GnRH with LH in the ovulation synchronization protocolin buffaloes in ovsynch protocol: Ovulation rate after the first GnRH was86.6% ;Ovulation rates 93.3% after the second dose of GnRH and 93.3%after LH .Ovulation occurred 36.4+/-10.4 h after the first GnRH. The interval fortreatment to ovulation was 26.5+/-9.6 h for buffaloes treated with GnRHand 24.4+/-7.9 h for buffaloes treated with LH ; the time of ovulationdid not differ statistically between the two groups (GnRH versus LH)Conception rates: 56.5% (GnRH) and 64.2% (LH). Therefore, theexogenous injection of LH can substitute the GnRH injections in theOvsynch program in buffaloes. (c) JEROME A de Araujo Berber et al. 2002
  26. 26. PGF2alpha treatmentThe dynamics of ovulatory follicular growth before oestrus were similarin buffaloes undergoing spontaneous and PGF(2alpha)-induced luteolysisand majority of buffaloes had a two wave pattern of follicular growthand emergence of a third wave was associated with a longer luteal phase. Warriach and Ahmad, 2007Efficacy of PGF(2alpha) for causing luteolysis and synchronizing estrusand ovulation in buffalo cows : dependent upon plasma progesteroneconcentration, CL size and ovarian follicular status before treatment. Brito et al. 2002 Studies by Sharma et al. 2009 using PG in subestrus Murrah heifersAll heifers, receiving 750 µg tiaprost, returned to estrus after meaninterval of 4.13±0.69 days.Majority of heifers (66.7%) ovulated the largest dominant follicle,present at the time of PG injection; while remaining 33.3% ovulated thesecond largest follicle.Ovulatory follicle grew @0.88±0.14 mm/day and reached a diameter of11.25±0.35mm on the day of estrus. (c) JEROME A
  27. 27. CL regressed @ 46.9±4.9 mm2/day and declined from 237.6±12.5 mmat treatment to 79.9±7.9 mm2 on the day of estrus. Pregnancy rate atestrus following treatment was 46.7% (7/15). Sharma et al. 2009Ovsynch: There is high degree of synchrony for estrus and ovulation incyclic buffaloes but developing CL fails to sustain its viability for fullcycle in 33% buffaloesThere is reduced diameter of ovulatory DF at induced estrus (13.45±0.82mm vs 15.08±0.64 mm at subsequent spontaneous estrus).Only one follicular ovulatory wave was recorded during short estrous cyclein contrast to two waves during normal length cycle. Malik et al. 2010. (c) JEROME A
  28. 28. Ovarian response to Ovsynch: BuffaloesLargest DF present at the time of 1st GnRH, ovulated or luteinized onlyin 33% buffaloes.In response to the 2nd GnRH, however, all buffaloes responded withovulations. largest DF which ovulated.In 78% buffaloes, the largest DF ovulated but it was the 2nd largest DFwhich ovulated in the remaining 22% buffaloes.Ovulation, characterized by sudden disappearance of the largest or the2nd largest ovarian follicle, occurred between 24-48 h after the 2ndGnRH in majority of treated buffaloes, with rare exceptions in whichovulation was recorded 24 h before the 2nd GnRH.These findings suggest greater synchrony of estrus and ovulationfollowing Ovsynch treatment of cyclic Murrah buffaloes. (Sharma et al. 2012) (c) JEROME A
  29. 29. ConclusionOvarian follicular dynamics in the buffalo species :similar to cattle in terms of follicular dynamics and basicendocrine mechanism - leading to the occurrence of thewave patternWaves seen from fetal and continue throughout the lifespan even during anestrus, pregnancyHormonal treatment, follicular ablation, presence ofcorpus luteum affects follicular dynamicsSeveral intra-follicular growth factors exertendocrine, autocrine or paracrine actions for folliculargrowth and differentiation needed for oocytecompetence (c) JEROME A
  30. 30. Thank you (c) JEROME A

×