RESUMO
Background: More recently, polyunsaturated fatty acids (PUFA) supplements have been used in grazing beef herds inattempt to influence specific metabolic pathways and hormones that directly modulate reproductive function. Supplementation of calcium salts of PUFA can positively influence ovarian follicular growth, luteal function, and improve reproductiveperformance in dairy and beef females. The aim of this experiment was to evaluate strategies of dietary treatments usingPUFA supplementation for 30 days before or after FTAI protocol and its effects on of ovulatory follicle size, ovulation,pregnancy and gestational losses rates in beef heifers.Materials, Methods & Results: One hundred and ninety-nine Brangus heifers (24 ± 3 months-old; BW= 320 ± 15 kg;BCS= 2.85 ± 0.17) were randomly assigned in three different groups to receive dietary treatments. Group 1 (n = 70) wasfed with 0.5 kg/day of a protein-mineral mixture supplement containing 0.2 kg/day PUFA (Mix A) during 30 days before FTAI, Group 2 (n = 68) received the same supplement 30 days after FTAI and Control (n = 61) only the supplementwithout PUFA (Mix B) during all period. Heifers were submitted to estrous synchronization treatment using progesterone(P4), estradiol benzoate (E2) and prostaglandin F2α (PGF). Ultrasound exams were done to measure ovulatory folliclediameter and to determinate ovulation and pregnancy rates on Days 30 and 60 after FTAI. Daily gain (DG) was higher (P< 0.05) only when heifers received supplement containing PUFA (Group 1= 30 days prior FTAI) and (Group 2= 30 daysafter FTAI). PUFA supplementation before FTAI also resulted in larger ovulatory follicles diameter (P < 0.05) in Group1 (11.2 ± 2.5 mm) compared to Group 2 (9.9 ± 2.3 mm) and Control (10.0 ± 2.07 mm). Ovulation rates were similar (P >0.05) in Group 1 (90%), Group 2 (75%) and Control (67%). Pregnancy rates were higher (P < 0.05) in Group 1 (Day 30=67.1% and...(AU)
Assuntos
Animais , Feminino , Bovinos , Ácidos Graxos Insaturados/análise , Ácidos Graxos Insaturados/uso terapêutico , Suplementos Nutricionais , Reprodução , Inseminação Artificial/veterinária , Técnicas de Reprodução Assistida/veterináriaRESUMO
Background: More recently, polyunsaturated fatty acids (PUFA) supplements have been used in grazing beef herds inattempt to influence specific metabolic pathways and hormones that directly modulate reproductive function. Supplementation of calcium salts of PUFA can positively influence ovarian follicular growth, luteal function, and improve reproductiveperformance in dairy and beef females. The aim of this experiment was to evaluate strategies of dietary treatments usingPUFA supplementation for 30 days before or after FTAI protocol and its effects on of ovulatory follicle size, ovulation,pregnancy and gestational losses rates in beef heifers.Materials, Methods & Results: One hundred and ninety-nine Brangus heifers (24 ± 3 months-old; BW= 320 ± 15 kg;BCS= 2.85 ± 0.17) were randomly assigned in three different groups to receive dietary treatments. Group 1 (n = 70) wasfed with 0.5 kg/day of a protein-mineral mixture supplement containing 0.2 kg/day PUFA (Mix A) during 30 days before FTAI, Group 2 (n = 68) received the same supplement 30 days after FTAI and Control (n = 61) only the supplementwithout PUFA (Mix B) during all period. Heifers were submitted to estrous synchronization treatment using progesterone(P4), estradiol benzoate (E2) and prostaglandin F2α (PGF). Ultrasound exams were done to measure ovulatory folliclediameter and to determinate ovulation and pregnancy rates on Days 30 and 60 after FTAI. Daily gain (DG) was higher (P0.05) in Group 1 (90%), Group 2 (75%) and Control (67%). Pregnancy rates were higher (P < 0.05) in Group 1 (Day 30=67.1% and...
Assuntos
Feminino , Animais , Bovinos , Reprodução , Suplementos Nutricionais , Ácidos Graxos Insaturados/análise , Ácidos Graxos Insaturados/uso terapêutico , Inseminação Artificial/veterinária , Técnicas de Reprodução Assistida/veterináriaRESUMO
Background: Programs of resynchronization of ovulation have the objective of allowing reinsemination of females that did not get pregnant after fixed time artificial insemination (TAI), in the lowest time interval possible. These protocols are usually composed of administration of estradiol benzoate (EB) concomitant to the insert of progesterone-based (P4) intravaginal implants 22 to 24 days after the first TAI. However, little information is available on the impact of hormonal manipulation in a pre-established pregnancy. The objective of this study was to evaluate if resynchronization of ovulation, started 24 days after the first TAI, would interfere in the function of the corpus luteum (CL), production of P4, and pre-established pregnancy.Materials, Methods & Results: For this study, 526 Brangus heifers with ages between 24 and 26 months, were subjected to TAI program in the beginning of the breeding season. Synchronization protocol for the first TAI started with insertion of an intravaginal implant containing 750 mg of P4 and administration of 2 mg of estradiol benzoate (EB) intramuscular (im) on day -9 (D-9). After seven days (D-2), P4 implants were removed, and 150 µg of D-cloprostenol (PGF), i.m., and 1 mg of estradiol cypionate (EC), i.m., were administered. The TAI was performed between 48 and 54 h after removal of the P4 implant (D0). Twenty-four days after the first TAI (D24), heifers were randomly divided into the following experimental groups: Control (n = 167, no treatment), EB (n = 208, 1 mg of EB, i.m.), and hCG (n = 151, 1000 IU of hCG, i.m.). Heifers of EB and hCG groups received a new intravaginal device containing 750 mg of P4 on D24. On day 31 (D31), P4 implants were removed and pregnancy diagnosis were performed by ultrasound. Pregnancy rates from the first TAI on D31 were 58.7% (98/167), 53.4% (111/208) and 52.9% (80/151) respectively for groups Control, EB and hCG.[...]
Assuntos
Feminino , Animais , Gravidez , Bovinos , Benzoatos/uso terapêutico , Estradiol/uso terapêutico , Gonadotropina Coriônica/uso terapêutico , Sincronização do Estro/métodos , Inseminação Artificial/veterináriaRESUMO
Background: Programs of resynchronization of ovulation have the objective of allowing reinsemination of females that did not get pregnant after fixed time artificial insemination (TAI), in the lowest time interval possible. These protocols are usually composed of administration of estradiol benzoate (EB) concomitant to the insert of progesterone-based (P4) intravaginal implants 22 to 24 days after the first TAI. However, little information is available on the impact of hormonal manipulation in a pre-established pregnancy. The objective of this study was to evaluate if resynchronization of ovulation, started 24 days after the first TAI, would interfere in the function of the corpus luteum (CL), production of P4, and pre-established pregnancy.Materials, Methods & Results: For this study, 526 Brangus heifers with ages between 24 and 26 months, were subjected to TAI program in the beginning of the breeding season. Synchronization protocol for the first TAI started with insertion of an intravaginal implant containing 750 mg of P4 and administration of 2 mg of estradiol benzoate (EB) intramuscular (im) on day -9 (D-9). After seven days (D-2), P4 implants were removed, and 150 µg of D-cloprostenol (PGF), i.m., and 1 mg of estradiol cypionate (EC), i.m., were administered. The TAI was performed between 48 and 54 h after removal of the P4 implant (D0). Twenty-four days after the first TAI (D24), heifers were randomly divided into the following experimental groups: Control (n = 167, no treatment), EB (n = 208, 1 mg of EB, i.m.), and hCG (n = 151, 1000 IU of hCG, i.m.). Heifers of EB and hCG groups received a new intravaginal device containing 750 mg of P4 on D24. On day 31 (D31), P4 implants were removed and pregnancy diagnosis were performed by ultrasound. Pregnancy rates from the first TAI on D31 were 58.7% (98/167), 53.4% (111/208) and 52.9% (80/151) respectively for groups Control, EB and hCG.[...](AU)