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2. An insemination programme to produce high fertility and hatchability with semen which had been deep frozen for 2 months was devised.
3. Over 90% fertile eggs with a 90% hatch of all eggs set was obtained with frozen and thawed semen over a period from the 2nd to the 12th day after the first of four inseminations. The persistency of fertility was also tested and 93, 86.6 and 30.7% of the eggs were fertile during days 2 to 6, 2 to 8 and 9 to 15 after the last insemination.
4. Corresponding with the high fertility rate, chicks were produced by every hen that was inseminated and from every male whose semen was frozen and stored. The implications for future breeding practices of this successful result are discussed. 相似文献
Follicles were identified during late anoestrus (between 100 and 60 days prior to the pre-ovulatory LH surge) and there appeared to be a shift in the population from small follicles (1–3 mm in diameter) to large follicles (>4 mm diameter) approximately 2 days prior to the LH surge. Corpora lutea could be reliably identified although the majority were cavitated. High ovulation rates (97–100%) and pregnant rates (86–100%) were detected, and although the conception rate was approximately 70% it varied between 8 and 92%. Within the narrow range of the clinical population studied there were trends relating age to reproduction performance. Oestrus induction with a gonadotrophin regime appeared to result in large numbers of small follicles that did not ovulate, whilst when using cabergoline the number of small and large follicels and the number of copora lutea were similar to those of control cycles. 相似文献
2. A series of alternative cryoprotective compounds were tested for their effect on fertility when fowl spermatozoa were inseminated fresh in their presence. Under these circumstances dimethylsulphoxide, dimethylaceta‐mide, ethane‐diol, propane‐diol and methylpyrrolidone did not depress fertility when used in concentrations equivalent to that of glycerol or in amounts reported previously to be non‐toxic and adequate to protect cells during freezing.
3. Dimethylacetamide was compared with propane‐diol for use in freezing fowl semen and the former enabled encouraging levels of fertility to be obtained. 相似文献
2. Single pre‐ovulatory peaks of plasma LH, androgen and progesterone were observed which took 8, 8 and 12 h respectively, to increase and return to base‐line values. The concentration of plasma prolactin tended to be elevated between 6 h before and 6 h after the LH peak with the maximum values occurring after the peak.
3. The changes in the concentrations of plasma LH and progesterone were 3‐ and 7‐fold respectively while 2‐fold changes were observed in the concentrations of plasma androgen and prolactin.
4. The pre‐ovulatory concentration of plasma progesterone and prolactin began to decrease 4 and 6 h respectively, after the pre‐ovulatory peak of LH.
5. Ovulation and oviposition occurred 6 to 8 h and 36.10+ 0.57 h (SEM) ( n= 11) respectively after the pre‐ovulatory peak of LH.
6. In birds kept on 14 h light/d, pre‐ovulatory peaks of LH were initiated only during a 10 to 11‐h period starting within 2 h after the onset of darkness.
7. A comparison between these data and those from the fowl suggest that the egg is retained in the turkey's oviduct for about 3 to 4 h longer than in the fowl. 相似文献