Carvalho N.A.T.,Unidade de Pesquisa e Desenvolvimento de Registro |
Soares J.G.,University of Sao Paulo |
Souza D.C.,Escritorio de Desenvolvimento Rural de Registro |
Vannucci F.S.,University of Sao Paulo |
And 5 more authors.
Theriogenology | Year: 2014
Three experiments were designed to evaluate the effect of different circulating progesterone (P4) concentrations during synchronization of ovulation protocol for timed artificial insemination of seasonal anestrous buffalo cows. In the first trial, ovariectomized cows were randomly allocated into one of three groups: using new P4 devices (G-New; n = 8), using devices previously used for 9 days (G-Used1x; n = 8), and using devices previously used for 18 days (G-Used2x; n = 8). The P4 device was maintained for 9 days, and the circulating P4 concentration was measured daily. The circulating P4 concentrations during the P4 device treatment were the lowest for G-Used2x (1.10 ± 0.04 ng/mL), intermediate for G-Used1x (1.52 ± 0.05 ng/mL), and the highest for G-New (2.47 ± 0.07 ng/mL; P = 0.001). In the second trial, 31 anestrous cows had their ovarian follicular dynamics evaluated after receiving the treatments described previously (G-New [n = 10], G-Used1x [n=11], and G-Used2x [n = 10]). At insertion of the P4 device, cows were administered 2.0 mg of estradiol benzoate. Nine days later, the P4 device was removed and cows were administered 0.53 mg of cloprostenol sodium plus 400 IU of eCG. Forty-eight hours after P4 device removal, 10 μg of buserelin acetate was administered. There were no differences among the groups (G-New vs. G-Used1x vs. G-Used2x) in diameter of the largest follicle at P4 device removal (9.0 ± 0.8 vs. 10.1 ± 0.9 vs. 8.6 ± 0.8 mm; P = 0.35), in interval from P4 device removal to ovulation (77.1 ± 4.5 vs. 76.5 ± 4.7 vs. 74.0 ± 4.4 hours; P = 0.31), or in ovulation rate (80.0% vs. 81.8% vs. 60.0%; P = 0.51). In experiment 3, 350 anestrous cows were randomly assigned into one of the three treatments described previously (G-New,n= 111; G-Used1x, n = 121; G-Used2x, n = 118) and received a timed artificial insemination for 16 hours after buserelin treatment. The 30-day pregnancy rates did not differ among groups (55.9% vs. 55.4% vs. 48.3%; P = 0.39). Thus, the low circulating P4 concentrations released from a used P4 device efficiently control the ovarian follicular growth and had no detrimental effect on the pregnancy rates of the seasonal anestrous buffalo cows. © 2014 Elsevier Inc. Source
Sales J.N.S.,University of Sao Paulo |
Sales J.N.S.,Federal University of Lavras |
Carvalho J.B.P.,Vale do Paraiba Regional Center |
Crepaldi G.A.,University of Sao Paulo |
And 5 more authors.
Theriogenology | Year: 2015
Four experiments were designed to evaluate the effect of different circulating progesterone (P4) concentrations during a synchronization of ovulation protocol for the timed artificial insemination (TAI) of Bos indicus (Nelore) beef cattle. In the first trial, 13 ovariectomized Nelore heifers were randomly allocated into one of three groups using new P4 devices (New; 1.0g P4), previously used P4 devices for 8days (Used1x), and previously used P4 devices for 16days (Used2x), in a crossover experimental design. The circulating P4 concentrations during the P4 device treatment were lower for Used1x (2.3±0.1ng/mL) and Used2x (2.0±0.1ng/mL) than those for New (3.8±0.2ng/mL; P=0.001). In the second trial, the ovarian follicular dynamics of 60 anestrous cows were evaluated after the cows received the treatments described previously (New [n=20], Used1x [n=20], and Used2x [n=20]). During the insertion of the P4 device, the cows were administered 2.0-mg estradiol benzoate. Eight days later, the P4 device was removed, and the cows were administered 0.53-mg sodium cloprostenol, 300 IU eCG, and 1-mg estradiol cypionate. There were no differences among the groups during the interval from P4 device removal to ovulation (73.7±2.9 vs. 69.8±2.4 vs. 68.4±2.3hours) or regarding the ovulation rate (70.0% vs. 80.0% vs. 85.0%). However, the maximum diameter of the largest follicle was greater (P=0.06) in the Used2x (15.3±0.4mm) than that of New (13.5±0.8mm) and Used1x (14.9±0.5mm). In experiment 3, 443 anestrous cows were randomly assigned into one of the three treatments (New [n=144] vs. Used1x [n=167] vs. Used2x [n=132]) and received a TAI 48hours after the P4 device removal. The diameter of the largest follicle during the device removal (10.7±0.3 vs. 11.2±0.2 vs. 11.3±0.3mm) and the 30-day pregnancy rates (51.4% vs. 53.9% vs. 43.2%) did not differ among the experimental groups. In experiment 4, a field trial with 593 B indicus (Nelore) cows was conducted to evaluate the pregnancy per AI using different levels of P4 in a TAI protocol (New [n=189] vs. Used1x [n=203] vs. Used2x [n=201]). The pregnancy per AI was similar between the treatment groups (63.5% vs. 57.6% vs. 62.7%). In conclusion, the low circulating P4 concentrations that were released from a used P4 device efficiently controlled the ovarian follicular growth and exhibited no detrimental effects on the pregnancy rates of the B indicus (Nelore) beef cattle. © 2015 Elsevier Inc. Source
de Carvalho N.A.T.,Unidade de Pesquisa e Desenvolvimento de Registro |
Soares J.G.,University of Sao Paulo |
de Souza D.C.,EDR CATI |
Maio J.R.G.,Ourofino Agronegocio |
And 4 more authors.
Buffalo Bulletin | Year: 2013
The present study aimed to evaluate the effect of using the intravaginal progesterone device for eight or nine days on the follicular response and pregnancy rate in lactating buffaloes synchronized for timed artificial insemination (TAI) during non breeding season. Two hundred and twenty buffaloes were randomly assigned according to age, parity, days postpartum, body condition score and ovarian activity into two groups: intravaginal progesterone device for 8 days (G-8d, n=110) or for 9 days (G-9d, n=110). At random stage of the estrous cycle (D0, PM) the buffaloes (G-9d) received an intravaginal progesterone device (P4) used a third time and 2.0 mg i.m. of estradiol benzoate (EB). On day 1 PM, buffaloes from G-8d received the same treatment described above for G-9d. On D9 (PM), buffaloes received 0.53 mg i.m. of PGF2 (Cloprostenol sodic) and 400 IU of eCG, followed by P4 device removal. After 48 h (D11, PM), the ovulation was induced by the administration of 10 μg i.m. of GnRH (buserilin acetate). In a subset of the buffaloes (G-8d, n=12 and G-9d, n=12), transrectal ovarian ultrasound examinations were performed on D0 to verify ovarian activity, on D9 to check the diameter of largest follicle and from D11 to D14 (12/12h for 60h) to verify the disappearance of the ovulatory follicle. All animals were submitted to TAI 64 h after P4 removal (D12, AM). Pregnancy examinations were conducted by transrectal ultrasonography 30 days after TAI. The variables were analyzed using the GLIMMIX procedure of SAS®. There were no difference between experimental groups (G-8d and G-9d) for all variables analyzed (P>0.05): diameter () of the largest follicle in D9 (9.3±0.7 vs. 10.3±0.4mm); of the ovulatory follicle (15.4±0.7 vs. 14.4±0.4mm); interval between P4 removal and ovulation (73.5±3,1 vs. 76.8±3.8h); ovulation rate [66.7% (8/12) vs. 83.3% (10/12)]; pregnancy rate [42.7% (47/110) vs. 50.9% (56/110)]. It was concluded that third used intravaginal P4 devices for eight or nine days resulted in satisfactory follicular response and pregnancy rate of the synchronized lactating buffaloes for TAI during the non breeding season. However, the 8.2% decreasing pregnancy rate in the G-8d should be considered in future investigations. Source
Use of algae Lithothamnium calcareum as alternative source of calcium in diets for broiler chickens [Uso da alga Lithothamnium calcareum como fonte alternativa de cálcio nas rações de frangos de corte]
Carlos A.C.,Sao Paulo State University |
Sakomura N.K.,Sao Paulo State University |
Pinheiro S.R.F.,Federal University of Vales do Jequitinhonha and Mucuri |
Toledano F.M.M.,J.Rettenmaier Latinoamericana Ltda |
And 2 more authors.
Ciencia e Agrotecnologia | Year: 2011
The objective of this study was to evaluate the use of the algae Lithothamnium calcareum (Pallas) Areschoug in diets for broiler chickens from 1 to 21 and 21 to 42 days, to replace the traditional source of calcium (limestone). 300 male chicks from Cobb® strain, which received diets containing limestone and Lithothamnium calcareum algae (as a whole and as sand biodentritic) were used as sources of calcium. The experimental design was completely randomized, with three treatments and five replicates of 20 birds each. The variables analyzed were: weight gain (g/bird), feed intake (g/bird), feed per again (g/g). At the end of the experiment the bone parameters: weight of the tibia (g), tibia length (mm), diameter of the tibia (mm) and ash content in the tibia (%). Were evaluated in the initial phase (1 to 21 days) there was an effect (P <0.05) between treatments for weight gain and feed per again, and the control treatment showed better results. For the growing phase (21 to 42 days) and total period (1 to 42 days) there was no effect among the treatments studied. The use of the algae Lithothamnium calcareum (independently of the harvest) to replace the traditional source of calcium (limestone) can be recommended for diets of broilers without affecting the growth performance. However, one should take into consideration the economic feasibility of using this alternative source in the diets. Source
Freire E.F.,University of Sao Paulo |
Borges K.B.,Federal University of Sao Joao del Rei |
Tanimoto H.,Ourofino Agronegocio |
Nogueira R.T.,Ourofino Agronegocio |
And 2 more authors.
Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment | Year: 2013
Ractopamine (RAC) analysis at all stages in the feed chain until its final mixing into swine feed is necessary to ensure the safety of all meat consumers and to decrease waste and the cost of supplementation of feed. Two suitable HPLC methods were developed and validated for RAC determination in vitamin mineral complex (VMC) and in swine feed. Both methods employed reverse-phase (C18 column at 40°C) and isocratic elution, but with some modifications to the methods. Validation parameters, such as selectivity, linearity, precision, trueness and robustness, were shown to be within the acceptable range. Therefore, the developed methods can be successfully applied for the monitoring of RAC concentrations in samples of VMC and swine feed ensuring economy to producers and security to consumers of swine meat. © 2013 Copyright Taylor & Francis. Source