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This work aimed to compare intake prediction equations with values obtained by direct methods using chopped elephant-grass offered to crossbreed lactating cows with rumen canulas. The experimental design was a 3 x 3 Latin square (three animals and three cutting ages: 30, 45 and 60 days). The equations used for intake prediction (y) were: (1) y= -1.19 + 0.035(a+b) + 28.5c; (2) y= [%NDF on DM]*[NDF intake]/[(1- a - b)/KP+b/(c+kp)]/24; (3) y= -0.822 + 0.0748(a+b) + 40.7c and (4) equation 2 with values of intake measured directly. The predictions of NDF intake by equations were not different among treatments, instead of the difference among values measured directly: the 30 day-old had lower intake (5.29 kg/day) in relation to 45 (6.57 kg/day) and 60 (7.31 kg/day) day-old grasses. In general, equations overestimated the DM intake in relation to direct measuring (9.0 kg/cow/day), with exception of equation 3 which underestimated the intake (7.7 kg/day). The means of DM intake found by equations 1 and 2 (13.7 and 13.4 kg/cow/day, respectively) were similar between themselves and superior in relation to those found by equation 4 (9.7 kg/cow/day). The intakes measured directly were similar to those found in equation 4 and higher than those found by equation 3. The mean of rumen fill of 7.5 kg was superior to those of 5.2 kg estimated by equation. The prediction equations based on in situ degradability parameters do not supply estimates of DM intake, NDF intake and rumen fill in agreement with values obtained by direct methods.

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The study of ovarian morphometry is directly related to its practical applications to interpret the examination of the reproductive tract of the cow. The objective of this work was to study the ovarian morphometry collected in slaughterhouse and correlations between corpus luteum area, progesterone and cortisol in no pregnant zebu cows. One hundred fourteen pairs of ovaries were collected from slaughterhouse, measured in thickness, length, width and volume, diameter and volume of the follicle, diameter and area of the corpus luteum. Significative difference (p<0.05) were observed for widths of (1.95 cm and 1.83 cm) and volume (p<0.05) of 7.26 ml and 6.23 ml of left and right ovaries respectively. For size and volume of follicles, and diameter and area of the corpus luteum, there was no significative difference between the sides. There was correlation of 0.46 (p<0.01) between left ovary volume × luteum corpus area, in the presence of follicles with diameters equal or greater than 9 mm, the corpus luteum of the massive and protuberant type were present in 23 (43.39%) of 53 ovaries, predominating in relation to type of massive and incluse 16 (30.18%). There were no significative correlation between corpus luteum area × progesterone, corpus luteum area × cortisol and progesterone × cortisol. In conclusion, the presence of the included corpus luteum in zebu cows could result in error during the rectal palpationexam to estimate the ovarian activity.

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Aiming to compare milk yield, residual milk and behavioral responses of Holstein cows during milking, fourteen experimental cows were mechanically milked twice a day, and evaluated during the first six weeks of lactation. Milk yield was measured daily, and residual milk volume weekly. Body (ribs region), udder and teat temperatures and respiratory frequency were measured twice a week. Animal behavior at the milking parlor was registered using ethograms and interviews with the milkers. During the first weeks of lactation, a higher percentage of kicks, over-steps, milking cups being knocked down, urinations and vocalizations in primiparous cows (p < 0.05) was observed, which were also considered more reactive by the parlors compared to multiparous cows. Multiparous cows produced more milk than primiparous (p < 0.05). However, there were no significant differences in residual milk percentage (p > 0.05), which suggests adaptation of both groups to the milking environment.

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This study aimed to compare conception rates at the postpartum period (PPP) in beef cows which were administered either Equine Chorionic Gonadotrophin (eCG) or Estradiol Benzoate (EB) after Norgestomet and submitted to fixed-time artificial insemination (FTAI). The hypothesis was that the administration of eCG or EB enhances the conception rate. Lactating Nelore cows (n=138) and Brangus (n = 63), between 26 and 118 days of post partum period (PPP) were divided into three homogeneous groups, and subdivided in two blocks, inside each group one of them with a PPP d'' 45 days (PPP1; n=107) and another with a PPP > 45 days (PPP2; n=94). All cows received an auricular implant containing 3mg Norgestomet (Crestar®), followed by the administration of 5mg Estradiol Valerate. The auricular implants were kept during 10 days. Cows received 1mL saline solution (n=68, Control Group) or 500IU eCG (Folligon®; n=67; eCG Group) or 1mg Estradiol Benzoate (Index, n=66; EB Group) 24 hours after the removal of the implant. FTAI was made 54 hours after the implant removal. The pregnancy diagnosis was carried through ultrasonography 30 days after FTAI. There was an interaction between treatments and PPP. In the PPP1, the conception rate was higher in the eCG Group than in the EB Group (47.22% vs. 15.38%; Pd''0.01). In the PPP2, the conception rates of the eCG and EB Groups were higher than in the Control Group (41.93%, 44.44% vs. 22.22%: Pd''0.01). It was concluded that in cows up to 45 days of PPP, the eCG associated with Norgestomet enhances the conception rates.

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The most important pathogens in the bovine livestock nowadays in the virus of the viral diarrhea mainly for triggered clinical manifestations related to the reproductive sphere. The infection in pregnant females, may result in abortions, embryonic resorptions, fetal mummification, birth of weak and malformation of the cattle. Moreover, their birth with persistently infected and immunotolerant virus, which the source of infection and dissemination of their disease. Nowadays, the complexity of the diagnosis and consequently its pathogenesis are tilted in the genotypic differences agent. So, this study aimed to verify the occurrence of the BVDV-1 (SINGER) and BVDV-2 (VS-253) genotypes in cows and their respective fetuses, slaughtered in an abattoir in the State of Sao Paulo. Through blood serum, using virus neutralization technique. All in all, 52,51% (115/219) of the cows which were tested reacted, but no fetus (0/219) reacted, to its virus neutralization. Through this cross-examination we observed that 42% (92/219) of cows reacted for both BVDV-1 and BVDV-2. Furthermore 4,10% (9/219) of them reacted only to the genotype BVDV-1 and 6,39% (14/219) responded only to the genotype 2 of BVDV. Therefore it was noticed that both strains are widespread in the regions studied, which justifies the use of different antigens to avoid false-negative diagnosis. Finally antibodies showed no fetus or fetal abnormalities, it is already developed and can be considered immunocompetent, independent child born to a reagent.

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In order to evaluate the effects of replacement of dried corn (GSM) for silage moisture corn (HMCS) on production and milk composition were used five Holstein cows, primiparous with a mean of 112 days post delivery, confined in Tie Stall, for 70 days. We used five diets according to NRC to 17.5% CP (DM) and 2.4 Mcal / kg DM, the 40:60 ratio of roughage and concentrate containing soybean meal, sugar cane silage and hay and substitution levels of the GSM HMCS the following treatments: a) 0%, 2) 25%, 3) 50%, 4) 75% and 5) 100%. Milk production and dry matter intake (DMI) were recorded daily. The animals were milked daily 6:00 and 18:00 h, and milk samples collected from consecutive milkings of each experimental period of 14 days (four days of collection). The experimental design was a 5x5 Latin square and the data analyzed by the statistical program SAS. Body weight (508 kg), milk (23.6 kg), corrected milk (22.7 kg), DMI (17.13 kg) showed no significant difference, but the intakes of neutral detergent fiber (6.67 kg), and detergent acid (3.39 kg), feed efficiency for the production of milk (milk 1.41 kg / day) urea nitrogen (17.67 mg / dL) differ, thus indicating that HMCS is more efficient than GSM in the diet of dairy cows not alter the production and milk composition.

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This study was conducted with the objective to evaluate the duration of exposure of animals to the evaporative cooling system in the waiting barn on the weather variables (temperature and relative humidity), animal behavior, production and quality aspects of milk from Girolando cows. Sixteen multiparous lactating cows were used having a genetic composition of 7/8 Holstein-Gir and mean milk production of 18 kg animal-1day-1. A 4 × 4 Latin square design was used. The experiment was conducted during the summer season (February-March 2009) and lasted 56 days. The treatments consisted of different periods of 10, 20 and 30 minutes of exposure to acclimatization and control. Time of 30 minutes of exposure to thermal conditioning system enabled the second milking (evening shift), providing an increase in milk production in the next milking of 0.640 kg animal-1. A higher percentage of time spent on food intake and rumination (17.31 and 30.19%) in 30 minutes treatment, compared to control (15.50 and 27.37%), respectively. There was no significant effect of treatments in the composition of milk.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)