Maternal Effects of Japanese Shorthorn Cows on the Growth of Embryo-transferred Japanese Black Calves in a Cow-calf Grazing System

The growth performance of embryo-transferred Japanese Black calves that were born from, and suckled by, Japanese Shorthorn cows in a cow-calf grazing system (BS-group, n = 5) was compared to that of Japanese Black calves from Japanese Black cows in a cowshed (BB-group, n = 5). The daily weight gain from birth to 1 month was higher in the BS-group than in the BB-group (p0.05) was observed between the groups. These results suggest that the maternal effect of Japanese Shorthorn cows was positive for embryo-transferred Japanese Black calf growth during the early suckling stage. As Japanese Black calves are traded at a high price on the Japanese market, we conclude that this proposed production system is likely to improve the profitability of herd management in upland Japan

ヒツジ インヒビン α サブユニット ノ ノウドウ メンエキ ガ クロゲ ワギュウ シュ ノ ランソウ キノウ ニ オヨボス エイキョウ ト ソノ カ ハイラン ユウキ ショリ オヨビ ソウシ セイサン エ ノ テキオウ セイ

インヒビン免疫はウシで排卵率を高めることが知られている。本研究では,組換え体ヒツジインヒビンαサブユニットを抗原とした黒毛和種牛への免疫が卵巣反応に及ぼす影響を検討した。また,過排卵誘起処置ならびに双子生産へのインヒビン免疫の適応性を調べた。免疫区として黒毛和種雌牛8頭に初回免疫時にインヒビンワクチン2mlを投与し,28日後に追加免疫として同量を投与した。対照区の5頭にはアジュバントのみを投与した。免疫後2-5ケ月の間,卵巣の変化を直腸検査ならびに超音波画像により追跡した。免疫区で観察した23発情周期中2および4発情周期について,それぞれ過排卵誘起処置ならびに双子生産を試みた。それぞれの試験に用いた供試牛は,発情日に人工授精を行い,過排卵誘起処置ではさらに人工授精後8日目に胚回収を行った。免疫区(23発情周期)では,発情卵胞(10mm≦)および黄体数は7.0±1.9,3.1±1.2であり,対照区(16発情周期)の1.1±2.2,1.1±1.4より多かった。免疫区では連続した発情周期で複数の卵胞発育および排卵が観察された。過排卵誘起処置では,2頭からそれぞれ4および9個の移植可能胚が得られ,胚移植の結果,3頭の産子が得られた。双子生産では4頭中1頭で双子が生産された。以上のことから,黒毛和種牛において組換え体ヒツジインヒビンαサブユニットの免疫は,連続した発情周期で複数の発情卵胞の発育ならびに複数排卵を誘発し,さらに過排卵誘起処置ならびに双子生産への応用が可能であることが明らかになった。なお,本研究は,性腺刺激ホルモンを併用しないインヒビン免疫のみによる過排卵誘起処置の成功例として,家畜における初の報告例である。Inhibin immunization increases the ovulation rate in cows. In this study we investigated the effect of active immunization of Japanese Black cows against the recombinant ovine inhibin α subunit on ovarian activity. In addition we examined whether inhibin immunization could be applied to superovulation and twinning in Japanese Black cows. Cows (n=8) were injected with 2ml of inhibin vaccine as primary injection at estrous day, followed by a booster injection (2ml) 4 weeks later. The control cows (n=5) received adjuvant only. Ovaries were examined by rectal palpation and using ultrasonography during 2 to 5 months after primary. Superovulation and twinning were attempted on 2 and 4 of 23 estrous cycles in immunized cows, respectively. The cows were run with artificial insemination at the day of estrus for both trials, and embryos were recovered for superovulation at 8 days after artificial insemination. The number of estrous follicles (10mm≦) and corpora lutea (7.0±1.9, 3.1±1.2, 23 cycles) of the immunized cows were higher than those of control cows (1.1±2.2, 1.1±1.4, 16 cycles). Multiple follicular development and ovulation were observed during successive estrous cycles in the immunized cows. In the superovulation trial, nine and 4 transferable embryos were recovered from each cow. The transferred embryos resulted in the birth of three calves. One of 4 cows of the twinning trial gave birth to twin calves. In conclusion, active immunization against the recombinant ovine inhibin α subunit induces successive multiple development of estrous follicles and multiple ovulation in Japanese Black cows. These experiments also show that inhibin immunization can be applied for superovulation in Japanese Black cows. In addition one twinning was induced in immunized cows. The present study is the first reported application of inhibin immunization resulting in successful superovulation in domestic animals

インヒビン メンエキ オ オコナッタ クロゲ ワシュ ギュウ ニ オケル ツイカ メンエキ オヨビ プロスタグランディン F2α

組換え体ヒツジインヒビンαサブユニットを抗原とした能動免疫は,ウシで複数の発情卵胞の発育と複数排卵を連続した発情周期で誘起することをすでに報告した。本研究では,インヒビン免疫により誘起される卵巣反応を効率的に維持および反復させるために,免疫効果の持続期間の延長と免疫牛における発情周期の短縮について検討した。組換え体ヒツジインヒビンαサブユニットを免疫した4頭の黒毛和種牛について,初回免疫後7カ月の間,2-3回の追加免疫を行い,その後の卵巣反応を調べた。さらに最終追加免疫後2カ月の間,プロスタグランディンF2αを併用し,その後の卵巣反応と発情周期日数を調べた。対照牛の5頭にはアジュバントのみを投与した。卵巣の変化は直腸検査ならびに超音波画像により追跡した。2回目の追加免疫後における発情時の卵胞数とその後の黄体数は,それぞれ17.2±3.6,9.6±2.9(最小自乗平均値±標準誤差,n=6)であり,1回目の追加免疫後(3.0±2.8,0.8±2.2,n=9)と比較して有意(発情時の卵胞数 ; P<0.01,黄体数 ; P<0.05)に増加した。さらに,3回目の追加免疫後,2回目の追加免疫後と同等の卵巣反応が再度誘起された。インヒビン免疫牛の発情周期日数(43.0±5.2,n=8)は,複数の黄体形成を原因として,対照牛(23.1±4.7,n=10)より有意(P<0.01)に延長した。しかし,プロスタグランディンF2αを併用した結果,発情時の卵胞数,黄体数を変化させることなく発情周期を対照牛と同等(18.4±5.2,n=8)まで短縮させることが可能であった。以上のことから,インヒビン免疫を行った黒毛和種牛において,追加免疫により長期にわたって複数排卵を反復して誘起させることが可能であり,さらにプロスタグランディンF2αの併用により卵巣反応に影響を及ぼすことなく発情周期を短縮させることが可能であった。We previously reported that active immunization against the recombinant ovine inhibin α subunit can enhance follicular development and increase the ovulation rate during successive estrous cycles in Japanese Black cows. However some problems have remained in efficiently inducing the ovarian reaction. The aims of this study were to examine the effects of repeated booster injections and prostaglandin F2α administration on ovarian activity and estrous cycle length in immunized Japanese Black cows in order to make the ovarian response more efficient. In four cows immunized against the recombinant ovine inhibin α subunit, two or three booster injections were given at various intervals over a period of 7 months. In addition, during the last 2 months following the final booster injection, immunized cows were treated three times with prostaglandin F2α. Five control cows received adjuvant only. Ovaries were examined by rectal palpation and by ultrasonography, and days of estrus were recorded. The second booster injection enhanced follicular development (17.2±3.6 vs. 3.0±2.8 P<0.01) and multiple ovulations (9.6±2.9 vs. 0.8±2.2 ; P<0.05) in comparison with the first booster injection. In addition, the third booster injection induced the same ovarian responses as the second booster injection. The length of the estrous cycle in immunized cows was significantly longer than that of the control cows (43.0±5.2 days vs. 23.1±4.7 ; P<0.01), due to multiple formation of CL. The prostaglandin F2α administration in immunized cows reduced estrous cycle length significantly (P<0.01) without any effect on ovarian response. In conclusion, repeated booster injections enhance the repeated ovarian responses in inhibin-immunized Japanese Black cows. In addition, utilization of prostaglandin F2α enabled the shortening of the length of the estrous cycle without any effect on ovarian response in inhibin-immunized cows

Attenuation of Leaky Rayleigh Wave: Experiment and Numerical

Attenuation is an essential characteristic of wave propagation, however, the quantitative measurement of bulk waves is not easy by the conventional immersion ultrasonic method because the diffraction and reflection losses are much higher [1] than the attenuation for common metals. Therefore we require samples of perfectly parallel and flat surfaces for this measurement. On the contrary, the attenuation of the leaky Rayleigh wave which propagates on the water/solid interface is noticeable [2–4] because of the energy leak from the solid surface into water. Thus the attenuation measurement of the leaky Rayleigh wave is relatively easy

Attenuation of Leaky Rayleigh Wave: Experiment and Numerical

Attenuation is an essential characteristic of wave propagation, however, the quantitative measurement of bulk waves is not easy by the conventional immersion ultrasonic method because the diffraction and reflection losses are much higher [1] than the attenuation for common metals. Therefore we require samples of perfectly parallel and flat surfaces for this measurement. On the contrary, the attenuation of the leaky Rayleigh wave which propagates on the water/solid interface is noticeable [2–4] because of the energy leak from the solid surface into water. Thus the attenuation measurement of the leaky Rayleigh wave is relatively easy.</p

Heat-shock-induced cathepsin B activity during IVF and culture compromises the developmental competence of bovine embryos

Heat stress can cause significant reproductive dysfunction in mammals and previous studies report that expression and activity of cathepsin B (CTSB), a lysosomal cysteine protease, is negatively correlated with the developmental competence of bovine oocytes and embryos. However, the relationship between heat shock (HS) and CTSB remains largely unknown. Here, we investigated the effects of HS during IVF and early embryonic stages of IVC on CTSB activity and developmental competence in bovine embryos. HS (40 C for 6 h during IVF and 20 h during IVC) caused a significant increase in CTSB activity irrespective of the developmental stage or duration of HS. The developmental rate to the blastocyst stage was also significantly decreased by HS. Additionally, HS during IVC significantly increased the number of apoptotic cells in blastocysts. Notably, these HS-induced changes in blastocyst development and quality were significantly improved by inhibition of CTSB activity, indicating a key role for CTSB. These results showed that CTSB activity plays an essential role in HS-induced dysfunction in bovine embryo development, and that inhibition of this activity could enhance the developmental competence of heat-shocked embryos. (C) 2018 Elsevier Inc. All rights reserved