Different superovulation protocols with fixed time artificial insemination in Bos taurus and Bos indicus / Diferentes protocolos de superovulação com inseminação artificial em tempo fixo em Bos taurus e Bos indicus

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

This study is presented in Chapter 1 (Superovulations protocols with FTAI for Bos taurus) and Chapter 2 (Superovulation protocols with FTAI for Bos indicus), in this Chapter are included three experiments [1 - Moment of the application of LH in cows Nelore (Bos indicus); 2 - Effect of the injectable progesterone administration in the day 0 in Nelore cows; 3 - Effect of the number of inseminations in superstimulated and fixed-time inseminated Nelore cows]. On Chapter 1, it went to evaluate the time of intravaginal P4 device (DIBTM) withdrawal and the application of LH in Holstein cows superstimulated with FTAI. Sixteen cows, treated with DIB (D-1) and 2mg of EB (D0) were assigned in four groups (superstimulation with 200mg of FSHp in 8 decreasing doses starting on D4). On D6, PGF was administered and the cows were accomplished in four groups: P24LH48; P24LH60; P36LH48 and P36LH60 (cross-over). The FTAIs were performed 12 and 24h after LH. The main effects for treatments P24 vs P36 and LH48vsLH60 were: ovulation rate (OR; 49.9±5.7 vs 60.9±4.8% and 53.1±5.3 vs 57.5±5.4%; P>0.05), total of structures (TS; 4.4±0.9 vs 5.0±0.9 and 3.8±0.7 vs 5.7±1.0; P>0.05), transferable embryos (TE; 3.0±0.7 vs 4.1±0.9 and 2.3±0.5a vs 4.9±0.9b; P<0.05) and suitable to freezing embryos (FE; 2.9±0.7 vs 3.8±0.8 and 2.1±0.5a vs 4.7±0.9b; P<0.05). The LH 60h after prostaglandin increased the TE and FE in Holstein cows. In the Chapter 2, it was studied different superstimulation with FTAI protocols in Nelore. In the first Experiment cows (n=20) were superovulated and treated with LH 48h (G-LH48) or 60h (G-LH60) after prostaglandin. There were no significant (P>0.05) differences in the variables between LH48 and LH60: number of follicles >8mm at the time of LH (FolLH12.5±1.5 and 9.4±1.0), OR [169/249 (71.0±4.2 %) and 120/187 (64.6±4.0%)]. However, there were differences (P<0.05) between G-LH48 and G-LH60 in the variables: interval first/last ovulation (IntOV15.0±2.1a and 21.0±1.7b), TS (7.5±1.0a and 5.1±0.5b), TE (6.2±1.0a and 3.1±0.5b), and FE (5.9±0.9a and 2.5±0.5b). The LH 48h after prostaglandin was more efficient in Nelore cows. In second experiment, ten Nelore cows were divided in two groups (D0): EB plus injectable progesterone group (G-BE+P4); or EB group (G-BE). The results for G-BE+P4 and G-BE were: follicular wave emergency in days (FE; 3.6±0.2 and 4.0±0.1; P>0.05), variation in FE [(2.5 to 4.5) and (3.5 to 4.5)], IntOV (32.4±1.8 and 33.6±1.6; P>0.05), TS (7.7±0.8 and 9.2±1.2; P>0.05), degenerated embryos (0.6±0.2 and 0.8±0.2; P>0.05), TE (6.2±0.6 e 7.2±1.1; P>0.05), and FE (5.1±0.7 and 6.3±1.0; P>0.05). The third Experiment, ten Nelore cows were divided in two groups: G-1IATF (16h after LH) or G-2IATF (12 and 24h after LH). The results for G-1IATF and G-2IATF were: FolLH (16.2±1.4 and 14.8±1.2; P>0.05), TS (8.2±0.9 and 7.2±0.8; P>0.05), TE (4.3±0.7 and 4.2±0.6; P>0.05), FE (2.9±0.6 and 2.8±0.4; P>0.05) and unfertilized structures (0.6±0.2 and 0.8±0.2; P>0.05). There was no difference on embryo production when the cows were inseminated one (16h) or two (12 and 24h) inseminations.

ASSUNTO(S)

embryo transter bos taurus superovulation and embryo production bos indicus superovulação e produção de embriões bos taurus bos indicus transferência de embrião

ACESSO AO ARTIGO

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