Ovarian follicular dynamics in Boran and Crossbred heifers in Ethiopia: Implications for assisted reproductive techniques

The study was conducted to characterize the follicular dynamics of purebred Boran (Bos indicus) and Boran * Holstein Friesian crossbred heifers  during estrous cycles; for use in ovum pick up and in-vitro embryo production. Insight of reproductive physiology of cattle would help to understand and exploit the reproductive potential of elite animals for breed improvement. Follicular development, growth and atresia during estrous cycles were evaluated using a trans-rectal real-time B-mode ultrasound system for three consecutive estrus cycles. Luteal activity was evaluated by serum progesterone level. Follicular aspirations were done to investigate the potential of Boran cattle and their crosses for transvaginal oocyte production; using a vacuum pressure pump and Aloka SSD Prosound-2 ultrasound device. Boran heifers (n=15) manifested two (n = 6, 40%), three (n = 5, 33%), four (n= 3, 20%) and five (n=1, 6.7%) follicular waves. Crossbred heifers (n=14) showed one (n= 2, 14%), two (n= 6, 43%) and three (n= 6, 43%) follicular waves. Interovulatory interval was 21.1 ± 3.4 and 21.4 ± 2.7 days for Boran (n=45) and crossbred (n=42) heifers, respectively. The progesterone level in Boran and Crossbred heifers during diestrus was 9.5 ± 11.0 and 4.6 ± 8.8 ng/ml, respectively. The maximum diameter of the ovulatory follicle for crossbred heifers was higher (15.4 ± 1.6 mm) than the diameter of the Boran (14.0 ± 1.9 mm) heifers (p<0.005). Differences (p<0.005) were observed in the size of both right (26.6 ± 5.14 and 28.6 ± 5.1 mm) and left (21.7 ± 4.85 and 24.1 ± 5.07 mm) ovaries of Boran and Crossbred heifers, respectively. Difference (p<0.005) was also observed in follicular count of the  right ovaries of Boran (4.84 ± 1.96) and Crossbred  (5.13 ± 2.05) heifers. Oocyte recovery rate in once weekly collection scheme for Boran and their crossbred heifers was (n=19, 42.08%) and (n=17, 42.55%), respectively. The recovery rate for twice weekly collection scheme was (n=24, 34.53%) and (n=23, 40.44%) for Boran and crossbred heifers, respectively. Follicular dynamics in Boran heifers is characterized by a higher incidence of cycles with two, three and four waves, associated with a low persistence of the dominant follicles; and smaller size of ovulatory follicles and less intense heat signs from their crossbred counterpart. Boran heifers proved to have potential for comparable number of follicular population and ease of aspiration procedures that can be tapped for advancedreproductive techniques. Keywords: Estrus cycle; follicular wave; ovarian follicle; ovum pickup; ultrasound

Evaluation of response to super-ovulation, estrous synchronization and embryo transfer in local Zebu or crossbred dairy cattle

An experiment was conducted at Holetta and Debre Zeit Agricultural Research Centers dairy herd in 2011 to evaluate the number of embryos collected per super-ovulated donor cow, estrus rate (ER) and pregnancy rate (PR) of recipient cows/heifers after embryo transfer. For super-ovulation treatment a total of 19 Holstein Friesian (HF) x Boran crossbred cows were selected as embryo donors and treated with super-ovulation hormones. For embryo recipient about 113 females of pure Boran and Holstein Friesian x Boran crossbred cows and heifers synchronized with estrous synchronization hormones. Out of 52 cows and heifers in estrous after estrous synchronization 34 of them used as embryo recipient out of which 23 females received fresh embryos and 11 frozen embryos. All data were analyzed using frequency distribution and Chi-square test. Results from super ovulation response indicated that out of 19 cows super-ovulated 15 (79%) cows responded to super-ovulation treatment. A total of 31 embryos collected out of which 23 embryos (77%) were transferable and the rest were not suitable for transfer. Mean number of embryo collected per donor was 2.07. Results from recipient estrous synchronization indicated that the overall recipient ER to estrous synchronization was 46% and significantly (P < 0.05) influenced by body condition score (BCS) while the effect of synchronization protocols, parity and breed were not significant. The overall recipient PR to embryo transfer was 20% and significantly influenced by BCS (P < 0.05). It can be concluded that the number of embryo obtained per super-ovulated donor in present study is low. Moreover recipient PR to embryo transfer was also very low. The poor PR of recipient females to embryo transfer could be attributed to high early embryonic mortality. Further research is required to investigate the possible cause of low number of embryo per donor cows and the poor PR of recipient females to embryo transfer

DAIRY TECHNOLOGY IMPACTS ON LIVEHOODS OF DAIRY PRODUCERS IN CENTRAL ETHIOPIA

A survey was conducted in 2012 to assess the impact of dairy technologies on the livelihood of dairying households in Ada’a and Lume districts of central Ethiopia. A total of 108 dairy farms were interviewed using structured questionnaire. Dairying has significant contribution as a sustainable source of income to the dairy producing households. It contributed about 62% and 66% of the total monthly income in Ada’a and Lume districts, respectively. Dairying was the first income source for about 80% and 62% of the dairy producing households in Ada’a and Lume districts, respectively. On the other hand, 92.9 % and 88.9 % of the respondents in Ada’a and Lume districts respectively explained that dairy technology adoption has significantly increased their household income. About 56% and 32% of households in Ada’a and Lume districts were found to save money from dairying in a traditional form of saving. Adoption of dairy technologies has also an impact on the consumption of milk and milk products as all family members in about 77.5% and 87.1% of households in Ada’a and Lume districts, respectively could consume more milk

DAIRY TECHNOLOGY IMPACTS ON LIVEHOODS OF DAIRY PRODUCERS IN CENTRAL ETHIOPIA

A survey was conducted in 2012 to assess the impact of dairy technologies on the livelihood of dairying households in Ada’a and Lume districts of central Ethiopia. A total of 108 dairy farms were interviewed using structured questionnaire. Dairying has significant contribution as a sustainable source of income to the dairy producing households. It contributed about 62% and 66% of the total monthly income in Ada’a and Lume districts, respectively. Dairying was the first income source for about 80% and 62% of the dairy producing households in Ada’a and Lume districts, respectively. On the other hand, 92.9 % and 88.9 % of the respondents in Ada’a and Lume districts respectively explained that dairy technology adoption has significantly increased their household income. About 56% and 32% of households in Ada’a and Lume districts were found to save money from dairying in a traditional form of saving. Adoption of dairy technologies has also an impact on the consumption of milk and milk products as all family members in about 77.5% and 87.1% of households in Ada’a and Lume districts, respectively could consume more milk

Effect of breed, parity and frequency of collection on quality and quantity of OPU derived oocytes

The aims of this study was to see the effect of breed, parity and scheme of collection on the quality and quantity of OPU derived oocytes and effect of transvaginal ultrasound guided follicular aspiration on subsequent fertility of donor cows. A total of 28 animals (11 Boran and 11 Boran Holstein-Friesian cross for once per week collection, and 7 Boran and 7 Boran Holstein-Friesian cross for twice per week collection) were used in this experiment. A total of 22 animals were evaluated for the effect of the OPU procedure on subsequent reproductive function. In 150 Ovum Pick up sessions, irrespective of collection scheme, breed and parity, 1124 follicle (554 in Boran and 570 in HF crosses) were punctured with a recovery rate of 51.1% in Boran and 48.6% in the crosses. Relatively more follicles were aspirated in crosses compared to Borans although the difference in oocyte recovery rate and quality were not statistically significant. Overall recovery rate was 57.7% in heifers and 42% in cows. Frequency of aspiration significantly influenced (P<0.05) oocyte recovery rate with more follicles aspirated in Once per week per session compared to twice per week per session but there was no difference in the mean number of recovered oocytes. A significantly higher number of follicles were aspirated (P<0.05) and good quality oocytes were greater in heifers than cows. Different COCs quality grades were recovered from breed, parity and frequency of collection category. Overall from a total of 574 collected COCs, about 326 (57%) of the recovered COCs were of the quality grades I and II, whereas 248 (43%) were with quality grades III and IV. All 22 animals showed estrus on average after 19 days of the last OPU procedure though a relatively weaker intensity of estrus signs, irregularity of the cycle and minor ovarian morphological change were noted. Response rate to a single PGF2α treatment on 18 animals was 72% (13/18). Subsequent insemination of those in estrus resulted in 53.8% (7/13) first service conception rate. In conclusion, parity, and to some extent frequency of collection had a significant effect on the quality and quantity of oocyte but not breed. Animals at post OPU were able to continue cycling and become pregnant

Responses of Holstein and Boran X Holstein Crossbred Cows to Super-ovulatory Hormones used for In vivo Embryo Production

አህፅሮት የቦስ ኢንዲከስ እና ቦስ ታውረስ የተባሉት የከብቶች ዝርያ ወይም ዲቃሎቻቸው በአንድ ጊዜ በዛ ያለ ዕንቁላሎችን እንዲያኮርቱ ለማድረግ ለሚሰጣቸው የሆርሞን ህክምና የተለያየ ምላሽ መስጠታቸው&nbsp; መሰረታዊ የሥነ-ተዋልዶ ባህሪይ ልዩነት እንዳላቸው ጥናቶች ያመለክታሉ፡፡&nbsp; በመሆኑም በፅንስ የማምረት ሂደት ውስጥ ተጨማሪ ዕንቁላሎችን እንዲያኮርቱ ለማድረግ ተመሳሳይ የአሰራር ሥልት መጠቀም የማይቻል መሆኑን ያሳያል፡፡ ስለዚህ የዚህ ጥናት ዋና ዓላማ ለቦስ ታወረስ የተመረጠ የአሰራር ሥልትን የሆሊስቲን ዲቃላ ለሆኑት የቦረና ላሞች ላይ በቀጥታ ከመጠቀም ይልቅ ምላሻቸውን በመመርኮዝ የአሰራር ሥልት መረጣ ለማድረግ የተደረገ ጥናት ነው፡፡ ይህንን ጥናት ለማድረግ ከ3 - 8 ዓመት ዕድሜ ያላቸውን 36 የቦረናና ሆሊሲቲን ዲቃላ ላሞችና ንፁህ ሆሊስቲን ላሞች ለሙከራው ተጠቅመናል፡፡ በሙከራው ጅምር ላይ ለ7 ቀናት የሚቆይ በብልታቸው ውስጥ ፕሮጄስትሮን ሆርሞን የተነከረ ሲ.ዳ.ር. የተቀመጥ ሲሆን ላሞቹን በሦስት ቡድን ተከፍለው 500፣ 650 እና 800 አይ.ዩ. ፕሉሴት (የኤፍ.ኤስ.ኤች. እና ኤል ኤች ሆርሞን ድብልቅ) ከ4ኛ ቀን እስከ 7ኛ ቀን በ12 ሰዓታት ልዩነት ጧትና ማታ ተሰጥቷቸዋል፡፡ በ7ኛ ቀን ከብልታቸው ውስጥ የተቀመጠው ሲ.ዳ.ር. ሲወጣላቸው ኢስትሩሜት ሆርሞን በመውጋት ለ72 ሰዓታት የኮርማ ፍላጎት እንደሚያሳዩ ለማረጋገጥ ክትትል ተደርጓል፡፡ በመቀጠልም ተጨማሪ ዕንቁላል ማኮረታቸውን ለማረጋገጥ አድገው ነግር ግን ያልተለቀቁ ዕንቁላሎችና የተለቀቁ ዕንቁላሎች ብዛት በአልትራሳዎንድ መሳሪያ ተቆጥሯል፡፡ ያልተፀነሱ ዕንቁላሎችና የተፈጠሩ ፅንሶች ተሰብስበው ተቆጥረው ተመዝግቧል፡፡ ተጨማሪ ዕንቁላል እንዲያኮርቱ ሆርሞን ከተወጉ ፅንስ ሰጪ ላሞች ውስጥ ከንፁህ ሆሊስቲን (8.67± 3.06) ይልቅ የቦረና እና የሆሊስቲን ዲቃሎች (15.45 ± 0.5) በቁጥር ከፍ ያለ ዕንቁላል መልቀቃቸውን የሚያሳዩ ምልክቶች እንዳላቸው ታይቷል፡፡ የተሰበሰቡት ፅንሶች ወይም ያልተፀነሱ ዕንቁላሎችን ቁጥር ሲታይም የቦርና ዲቃሎች ከንፁህ ሆሊስቲን የበለጠ በዛ ያለ ቁጥር የሰጡ መሆኑ ታይቷል፡፡ በጣም የጎላ ልዩነት ባይኖርም ከሦስቱ የፕሉሴት ዶዝ መጠን ውስጥ የ650 አይ.ዩ. የወሰዱት እንስሳት የተሻለ የፅንስ ቁጥር እና የተለቀቁ ዕንቁላሎች ብዛት አስገኝቷል፡፡&nbsp; ከአምስቱ የአካል ሁኔታ ምዘና መስፈርት (ከ2.5 እስከ 5 መካከል ያሉት ተወስደው) በ3.5 እና 3.8 ነጥብ መካከል ያሉት ላሞች ከፍተኛ ቁጥር ያላቸው ዕንቁላሎችን (15.74 ± 0.59፤ 14.33 ± 2.90 በቅደም ተከተል) የሰጡ ሲሆን በ3.8 ነጥብ ላይ ያሉት በቁጥር የተሻለ ዕንቁላል/ፅንስ ሰጥተዋል፡፡ ከዚህ በመነሳት የቦረና እና የሆሊስቲን ዲቃላ ላሞች ተጨማሪ ዕንቁላል እንዲያኮርቱ ለተሰጣቸው የሆርሞን ህክምና ለአነስተኛ ዶዝ የተሻለ ምላሽ የሚሰጡ መሆኑንና &nbsp;ባለ 650 አይ.ዩ. ዶዝ ሆርሞን በሁሉም መስፈርት በቦረና እና ሆሊስቲን ዲቃላ ላሞች ላይ የተሻለ ውጤታማ መሆኑ ተረጋግጧል፡፡ &nbsp; Abstract Variability in the response to super-ovulatory treatments in Bos indicus, Bos taurus, and their crosses was reported to be a fundamental biological difference in reproductive function between them and has been a major barrier to the adoption of similar superovulation protocols. Therefore, this study was designed to optimize the super-ovulatory protocol for the Boran x Holstein crossbred cows. A total of 36 Boran x Holstein crossbred and pure Holstein cows 3-8 years of age were utilized for this study. A 7-day CIDR treatment was initiated on Day 0, and cows were treated on Days 4-7 with 500, 650, or 800 IU of Pluset® (combined FSH and LH product) administered at 12-hour intervals in a decreasing dose regimen. Estrumet (Prostaglandin F2α analogue) was given on day 7 before CIDR withdrawal. Each super-ovulated cow was monitored for 72 hours to assess behavioral estrus in response to super-ovulatory treatment. Ovarian response was also assessed by counting the number of corpora lutea and number of un-ovulated follicles via transrectal ultrasound scanning, the number of total collections, and the number of viable embryos. From the super-ovulated donor cows, Boran X Holstein crosses had a higher (P&lt;0.009) number of corpora lutea (15.45 ± 0.5) than pure Holstein (8.67± 3.06). The number of collected embryos/oocytes and the number of viable embryos collected was significantly higher for crossbred cows (p&lt;0.01, p=0.06) than the pure Holstein cows. Although it was not statistically significant, from the three Pluset® (combined FSH and LH product) dose levels the 650 IU dose have produced a higher response in terms of corpora lutea number and number of collected viable embryos. From the five-scale body condition scoring (Recorded 2.5 to 5) cows with 3.5 and 3.8 scales have produced a higher number of corpora lutea (15.74 ± 0.59; 14.33 ± 2.90, respectively), while those with 3.8 scores had the highest total number of collections (6.33 ± 2.60). From the findings, it can be concluded that Boran X Holstein crossbred cows have a better ovarian response to lower doses of exogenous gonadotropins than pure Holstein cows. The 650IU Pluset® dose level is the optimal level for superovulation of crossbreeds. &nbsp

Ovarian follicular dynamics in purebred and crossbred Boran cows in Ethiopia

Boran is an endangered breed of cattle indigenous to Ethiopia and the relatively poor understanding of its reproductive physiology has impeded efforts to maximize reproductive performance of the breed. This study characterized ovarian follicular dynamics in 9 purebred Boran and 8 Boran×Holstein (B×H) crossbred cows. Ovaries of all 17 cows were examined once per day for 61 consecutive days (encompassing three periods of estrus) using transrectal ultrasonography. The mean (±standard error of mean) inter-ovulatory interval (IOI) was similar (P>0.05) in Boran (19.4 ± 0.2 days) and B×H cows (20.1 ± 0.4 days). Two (in 79% of estrous cycles) or three (in 21% of cycles) follicular waves per IOI were observed and IOI was shorter (P0.10) in both genotypes (15.8 ± 1.5 mm in Boran and 19.4 ± 2.9 mm in B×H). Boran cows possessed a greater (P<0.001) total number of ovarian follicles than BxH cows and both genotypes displayed more (P<0.05) activity on their right than left ovary. Results of our study have provided novel insights into the normal reproductive physiology of the Boran breed

Ovarian follicular dynamics in purebred and crossbred Boran cows in Ethiopia

Boran is an endangered breed of cattle indigenous to Ethiopia and the relatively poor understanding of its reproductive physiology has impeded efforts to maximize reproductive performance of the breed. This study characterized ovarian follicular dynamics in 9 purebred Boran and 8 Boran×Holstein (B×H) crossbred cows. Ovaries of all 17 cows were examined once per day for 61 consecutive days (encompassing three periods of estrus) using transrectal ultrasonography. The mean (±standard error of mean) inter-ovulatory interval (IOI) was similar (P>0.05) in Boran (19.4 ± 0.2 days) and B×H cows (20.1 ± 0.4 days). Two (in 79% of estrous cycles) or three (in 21% of cycles) follicular waves per IOI were observed and IOI was shorter (P0.10) in both genotypes (15.8 ± 1.5 mm in Boran and 19.4 ± 2.9 mm in B×H). Boran cows possessed a greater (PThis article is published as Degefa, Tamrat, Alemayehu Lemma, Jeilu Jemal, Gbremeskel Mamo, Azage Tegegne, and Curtis R. Youngs. "Ovarian follicular dynamics in purebred and crossbred Boran cows in Ethiopia." African Journal of Biotechnology 15, no. 33 (2016): 1763-1770. doi:10.5897/AJB2016.15267. Posted with permission.</p