Ciro Alexandre Alves Torres

Relação da taxa de gestação com sêmen bovino congelado e testes de avaliação espermática in vitro

The objective of this study was to evaluate the relationship between complementary (hiposmotic, thermo-resistance and acrosome reaction tests) and conventional evaluations (physical and morphologic aspects) of bovine frozen/thawed semen and conception rates. Average values for spermatic motility evaluated by thermo-resistance test were of 53.48% (post-thawed), 43.69% (60 minutes), 35.88% (120 minutes) and 33.04% (180 minutes). The percentage of reactive cells observed for the hiposmotic test was 37.89%. Average intensity was observed for post-thawing spermatic motility, positively correlated to hiposmotic test (0.21). However, correlation between motility in the 180 minutes and hiposmotic test was high (0.64). The percentage of cells presenting post-thawing acrosome reaction was 9.85%, which was negative correlated to post-thawing (-0.25) and after three hours of incubation (-0.46) spermatic motility. No correlation was observed for complementary tests and post-thawed motility and the conception rate. No one of the parameters evaluated in this study was individually able to indicate the fertilizing capacity of the frozen/thawed semen.

Uréia para vacas leiteiras no pós-parto: desempenhos produtivo e reprodutivo

Fifteen crossbred cows (Holstein-Zebu) from EPAMIG-Leopoldina Experimental Farm with an average weight of 511.8 kg were allocated into an experiment in a complete randommized design, in four treatments, with four animals in the treatments 1, 2, and 4 and three in the treatment 3. The treatments were cosntituted of diets with corn silage and concentrate (60:40) and were fed individually and ad libitum and their contents in percentage of urea were: T1=0.0; T2= 0.7; T3= 1.4 and T4=2.1 corresponding to the 2.08; 4.01; 5.76 and 8.07% of crude protein in the form of non-protein nitrogen (NNP), respectively. The average dry matter intake (DMI) expressed in kg/day and in the percentage of body weight were: 16.04; 16.49; 11.64; 11.93 and 3.29; 3.09; 2.47 and 2.35, respectively. The milk production for 3.5% of fat were: 21.18; 24.92; 20.63 and 18.83 kg/day for the NNP concentrations of 2.08; 4.01; 5.76 and 8.07, respectively and decreased with the increase of NNP concentrations in the rations. The mean plasma concentrations of urea and N-urea were: 46.33 and 21.59 mg/dL, and were not affected by the concentrations of NNP in the diets. The number of follicular waves per cycle and the emergency of the first and second follicular waves and its diameter were not affected by the concentrations of NNP in the diets. The first estrus and ovulation occurred on days 55±23 and 81±36, respectively and were not affected by the NNP concentrations of the diets.Fifteen crossbred cows (Holstein-Zebu) from EPAMIG-Leopoldina Experimental Farm with an average weight of 511.8 kg were allocated into an experiment in a complete randommized design, in four treatments, with four animals in the treatments 1, 2, and 4 and three in the treatment 3. The treatments were cosntituted of diets with corn silage and concentrate (60:40) and were fed individually and ad libitum and their contents in percentage of urea were: T1=0.0; T2= 0.7; T3= 1.4 and T4=2.1 corresponding to the 2.08; 4.01; 5.76 and 8.07% of crude protein in the form of non-protein nitrogen (NNP), respectively. The average dry matter intake (DMI) expressed in kg/day and in the percentage of body weight were: 16.04; 16.49; 11.64; 11.93 and 3.29; 3.09; 2.47 and 2.35, respectively. The milk production for 3.5% of fat were: 21.18; 24.92; 20.63 and 18.83 kg/day for the NNP concentrations of 2.08; 4.01; 5.76 and 8.07, respectively and decreased with the increase of NNP concentrations in the rations. The mean plasma concentrations of urea and N-urea were: 46.33 and 21.59 mg/dL, and were not affected by the concentrations of NNP in the diets. The number of follicular waves per cycle and the emergency of the first and second follicular waves and its diameter were not affected by the concentrations of NNP in the diets. The first estrus and ovulation occurred on days 55±23 and 81±36, respectively and were not affected by the NNP concentrations of the diets.

Indução de estro em cabras da raça Toggenburg com dois diferentes dispositivos intravaginais

Twelve Toggenburg breed nuliparous female goats were randomly assigned to two treatments intended to induce estrus. On day zero, animals on T1 (n=6) were treated with an intravaginal sponge impregnated with 60mg of medroxyprogesterone acetate plus 50µg of PGF analogue. The T1 goats received eCG (250IU) on day 4, and on day 5 the sponge was removed. The T2 goats (n=6) received CIDR-G® as intravaginal sponge plus 50mg of PGF analogue. All goats expressed behavioral estrus, and the pregnancy rates were 83.3 (5/6) and 33.3% (2/6) for T1 and T2, respectively. The interval from withdrawal of the device to onset of estrus did not differ between treatments (P>0.05). Ovulatory traits also were not affected by treatments. The interval between CIDR-G® removal and ovulation for T1 and T2 goats were similar (P>0.05). Both sponge and CIDR-G were equally efficient in inducing the estrus behavior in goats.

Avaliação espermática e da concentração de proteínas solúveis no plasma seminal de bodes da raça Alpina em regime de monta controlada

Foram estudadas as relacoes entre a concentracao de proteinas soluveis do plasma seminal, o teste hipoosmotico, a analise fisica e morfologica do semen e o desempenho reprodutivo de bodes da raca Alpina em regime de monta controlada. O experimento foi realizado durante os meses de fevereiro a abril de 2001. Foram realizadas 40 coletas de semen em quatro reprodutores adultos em regime de monta controlada. Em todas as coletas, alem do exame fisico e morfologico do semen, foram realizados os testes hipoosmoticos, isoosmoticos e a determinacao da concentracao de proteinas soluveis do plasma seminal. Foi detectada diferenca entre os bodes na concentracao de proteinas soluveis do plasma seminal, mas nao houve diferenca no teste hipoosmotico e no numero de coberturas por prenhez. O teste hipoosmotico pode ser uma importante ferramenta para a avaliacao de semen caprino, mas a concentracao de proteinas soluveis do plasma seminal nao pode ser utilizada como parâmetro para predizer a qualidade seminal e a fertilidade de bodes da raca Alpina utilizados em regime de monta natural.

Lisina em rações para fêmeas suínas primíparas em lactação

Fifty crossbred primiparous sows averaging weight of 210.3 ± 22.5 kg were used to evaluate the total lysine levels (0.95, 1.03, 1.10, 1.18 and 1.25%) in the diet, during lactation (17.69±1.17 days). A randomized blocks design with five treatments and ten replicates the sow as the experimental unit was used. During the experimental period, the sows were daily fed 4.3 kg of diet. Lysine intake increased linearly, in response to the dietary lysine levels. The productive and reproductive parameters of the sows were not influenced by the dietary lysine levels. Piglet weight gain did not change with the sow lysine intake. It was concluded that the total lysine level correspondent to a daily intake of 40.47 g met the lysine requirements of lactating primiparous sows.

Características da dinâmica folicular e regressão luteal de vacas das raças Gir e Nelore após tratamento com cloprostenol sódico

ABSTRACT - The follicular dynamics and luteal regression were studied in 12 Gir and seven Nelore cows, treated with analogprostaglandin F 2 α, between day 10 and 12 of the estrous cycle. The synchronization rate was higher than 92% for the two breeds, andthe ovulation of second dominant follicle occurred in 72.7% of Gir and all Nelore cows. Ovulatory follicle diameter for Nelore was lower(11.0 ± 0.9 mm) than Gir cows (13.0 ± 1.7 mm). The average intervals from treatment to estrus, treatment to ovulation time and fromthe beginning of the estrus to ovulation were 88.7 and 91.6h, 119 and 113h, 26.5 and 24.3h for Nelore and Gir cows, respectivel y.Key Words: bovine, corpus luteum, estrus synchronization, luteolitic, zebu 1 Parte da tese de Doutorado do primeiro autor, parcialmente financiada pela FAPEMIG. 2 Med.Vet. autonomo – DsC – Rua Cap. Neves , 408. CEP: 37.170-000 B. Esperanca – MG. Bolsista do CNPq. E.mail: amborges@hotmail. com 3 Professor do Departamento de Zootecnia da UFV – Av. PH Holfs, s/n

Uso de dimetil-formamida associada ou não ao glicerol na criopreservação de sêmen caprino

The objective of this trial was to evaluate the efficiency of dimethylformamide on cryopreservation of goat semen using semen physical analyses and complementary tests. Alpine and Saanen bucks from the Dairy Goat Experimental Station- DZO were used. Semen samples were frozen with a yolk-skimmed milk diluent and cryoprotectors with different concentrations as follows: 7% glycerol (T1), 3.5% glycerol plus 3.5% dimethylformamide (T2) or 5% dimethylformamide (T3). Semen was centrifuged, diluted, and bottled in 0.5 mL straws followed by cooling for 40 minutes until reach 5.0°C and kept at this temperature for additional 80 minutes. Samples were then exposed to liquid nitrogen vapor for 15 minutes and finally frozen. Thawing was done in a waterbath at 37°C for 50 seconds. The following variables were evaluated in vitro: sperm progressive motility and vigor, acrosomal integrity and reaction, and plasmatic membrane integrity. The cryopreservation procedures reduced 30.0% of the initial motility and 19% of plasmatic membrane integrity that was evaluated using the hyposmotic swelling test (HOST). It was observed an increaseof 3% in acrosomal lesions when samples were submitted to a slow thermoresistance test (TRT). No significant differences in sperm motility were observed among treatments at 0, 5, and 60 minutes of TRT as well as in sperm vigor at all TRT times. However, at 120 minutes of TRT a significant difference in sperm motility was found comparing T1 and T2 while T3 was intermediate. There were no significant differences on plasmatic membrane integrity, acrosomal integrity, and post-thawing acrossomal reaction across treatments. It can be concluded that dimethylformamide can be a viable alternative for goat semen cryopreservation used alone or in association with glycerol.

Avaliação do comportamento sexual em touros Nelore: comparação entre os testes da libido em curral e do comportamento sexual a campo

The objectives of this study were to determine the efficiency of the libido test in corral compared to the test performed at field and to relate them to the gestation rate observed in a breeding season of 120 days. Thirteen Nelore bulls able to reproduce were submitted to the libido test in corral for 3 hours and evaluated by scores every five minutes. Nine of them were submitted to evaluation at field using a bull:cow proportion equal to 1:33. The gestation was diagnosed every 21 days through ultrasonographic evaluation. During the test in corral, the classification scores increased as the testing time increased, but no bull accomplished complete service in the first 10 minutes of the test. A very good bull obtained 84.80% for pregnancy rate, but other questionable bulls obtained 86.67 and 96.55% at the end of the breeding season. Correlations estimates among physical and morphologic characteristics of the semen were close to zero or null. The main physiologic indicators of the bull sexual behavior were: smelling or licking the female body, smelling or licking the vulva, followed or not by the Flehmen reflex. The results suggested 30 minutes of observation as the most efficient time to evaluate the libido test in corral. The libido test at field during daytime was not effective probably because of the sexual behavior of some bulls at night.

Exigência de proteína e composição da carcaça de galos reprodutores de 27 a 61 semanas de idade

Two trials were carried to estimate the protein requirements and carcass composition of male broiler breeders from 27 to 61 weeks of age. Four hundred and fifty females and 75 males of Cobb-500 strain were selected to evaluate the body weight, semen volume, spermatic concentration, mobility, vigor and fertility of spermatozoa. Thirty males were used for evaluation of carcass chemical composition (DM, CP and crude fat [CF]) as a function of protein intake. The experiment was analyzed as a complete randomized design with five treatments (12.0, 14.2, 16.4, 18.6, and 20.8 g CP/bird/day). In the first trial (reproductive performance evaluation), each treatment was composed by 15 replicates of one rooster and in the second trial (carcass evaluation), each treatment consisted of two replicates of three roosters (three were slaughtered at 45 weeks and three at 61 weeks of age). Quadract effect of CP intake on semen volume, spermatic concentration, motility, spermatozoa vigor and fertility was observed. Only body weight and DM percentage were not affected by treatments. However, at extreme levels (deficiency or excess) of protein intake, CF percentage in the carcass increased and the reproductive performance decreased. Therefore, the intake of 16.9 g of CP/rooster/day is recommended to meet CP requirements of male broiler breeders from 27 to 61 weeks of age.

Sincronização de estro com CIDR reutilizado em cabras lactantes da raça Toggenburg tratadas com somatotropina bovina recombinante (r-bST)

The response of goats treated with r-bST in the estrous synchronization protocol was evaluated. Twenty-six Toggenburg females were divided in two treatments: T1 (n=13) treated with four injections of 250mg r-bST, at 14 days intervals, and T2 (n=13) treated with saline solution (control). The intravaginal device previously used by five days was inserted (day 0) one week after the last injection of r-bST and PGF2a (22.5µg) was injected in the animals of both treatments. The device was removed on day 6. All the females in estrus were bred by fertile bucks. The percentage of animals in estrus and the pregnancy rate were: 76.9 and 70, and 84.6 and 72.7% for goats in T1 and T2, respectively. The estrous cycle length; the interval from treatment to the onset of estrus; the ovulation number; and the intervals from the onset of estrus to ovulation, end of estrus to ovulation, and from device removal to ovulation were not affected by r-bST injection. The r-bST did not affect the diameter of the ovulatory follicles (P>0.05). Progesterone concentration showed similar values (P>0.05) among the goats of T1 and T2 during the treatment with device. The r-bST administration did not affect estrous synchronization.