This study evaluated the effects of the synchronization of ovarian follicular wave emergence on the efficiency of in vitro embryo production. Bos indicus cows (n = 20) were divided into two groups (control vs. synchronization) and subjected to repeated ovum pick-up (OPU) sessions (8 replicates each, with an interval of 21 days in a 2 × 2 crossover design) and subsequent in vitro embryo production. Cows in the control group (n = 10) were submitted to OPU procedures without any stimulation every 21 days. Animals in the synchronization group received a protocol-based progesterone implant, estradiol benzoate and prostaglandin on a random day of the estrus cycle (Day 0) and the OPU was performed on Day 5. After in vitro production, embryos were transferred to recipients synchronized at a fixed time and the diagnosis was performed 60 days later. An evaluation of the parameters for each OPU session revealed that donors that received the synchronization protocol pre-OPU showed a greater number of embryos (5.9 ± 0.5 vs. 4.5 ± 0.4; P = 0.037), higher rate of embryo production (45.8% vs. 38.5%; P = 0.001) and higher mean number of conceptions per group (2.2 ± 0.2 vs. 1.6 ± 0.2; P = 0.07) in relation to the group that did not receive hormonal treatment. We concluded that synchronization of the follicular wave prior to OPU showed positive effects on in vitro embryo production as well as on pregnancy rates.

RESUMO -O estudo foi desenvolvido no Município de Astorga, PR, na Fazenda Nossa Senhora de Aparecida, com o objetivo de avaliar as características da pastagem e o acúmulo de forragem em capim-Tanzânia (Panicum maximum Jacq.), diferido e após pastejado no período de 23/07 a 18/09/1999, sob diferentes níveis de altura de pasto. O delineamento experimental usado foi o inteiramente casualizado, com duas repetições. Os tratamentos foram quatro alturas de pasto: T 1 =20, T 2 =40, T 3 =60 e T 4 =80 cm. Entretanto, para a análise estatística, utilizaram-se as alturas reais de pasto mantidas nas unidades experimentais, sendo: T 1 R 1 = 26,3, T 1 R 2 = 24,6, T 2 R 1 = 47,9, T 2 R 2 = 42,5, T 3 R 1 = 55,8, T 3 R 2 = 61,7, T 4 R 1 = 69,2 e T 4 R 2 = 71,4 cm. Pode-se concluir que a altura de pasto aumenta de forma linear as massas de forragem e de colmos verdes. O acúmulo de forragem não foi afetado pelas diferentes alturas de pasto.Palavras-chave: diâmetro de touceira, lâmina foliar, massa de forragem Sward Characteristics of Deferred Tanzania Grass under Different Height Levels, in the Winter TimeABSTRACT -The study was carried out in the county of Astorga, PR, Brazil, in the Nossa Senhora de Aparecida farm. The objective was to study the sward characteristics and forage accumulation of tanzania grass, deferred and after grazed from 07/23 to 09/18/1999, under different sward height levels. The experimental design was a completely randommized, with two replications. The treatments were four levels of sward height: T 1 =20, T 2 =40, T 3 =60 and T 4 =80 cm. However, the true sward height levels were used for analysis statistics; T 1 R 1 =26,3, T 1 R 2 =24,6, T 2 R 1 =47,9, T 2 R 2 =42,5, T 3 R 1 =55,8, T 3 R 2 =61,7, T 4 R 1 =69,2 e T 4 R 2 =71,4 cm. Results indicate that: forage mass and green culm mass increased of the positive linear way with increased of sward height. There was no effect of sward height levels on the forage accumulation.Key Words: forage mass, leaf lamina, tuft diameter 1 Professor do Departamento de Zootecnia da UEM -Campus Universitário -Av. Colombo, 5790, CEP 87020-900, Maringá -PR. E.mail: ucecato@uem.br 2 Bolsista do grupo PET/ZOO/UEM -Campus Universitário -Av. Colombo, 5790, CEP 87020-900, Maringá -PR. 3 Acadêmicos do curso de graduação da UEM -Campus Universitário -Av. Colombo, 5790, CEP 87020-900, Maringá -PR. Rev. bras. zootec., 30(4):1186-1193, 2001Introdução Conforme os estudos de CORSI (1995) e EUCLIDES (1995), pastagens de Panicum maximum apresentam alta capacidade de produção de forragem e bom valor nutritivo. Para o caso da região noroeste do Paraná, a cultivar de Panicum maximum Tanzânia também tem se mostrado como altamente promissora, segundo os experimentos de MACHADO et al. (1998) e BARBOSA (1998. No entanto, são poucos os estudos relativos a essa cultivar, durante o período de inverno, que envolve diferimento e manejo do pastejo, utilizando-se como critério a altura de pasto.No que concerne às características da condição do pasto, como a massa de forragem (MF)/ha, massa de forragem v...

RESUMO -O objetivo deste trabalho foi avaliar o efeito da substituição do milho pela farinha de mandioca de varredura, em dietas de cabras Saanen em lactação, sobre o desempenho, a composição do leite (sólidos totais e proteína bruta), a digestibilidade da matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), extrato etéreo (EE), fibra insolúvel em detergente neutro (FDN), e amido e a concentração dos nutrientes digestíveis totais (NDT) das dietas. Foram utilizadas quatro cabras há 100 dias em lactação. O delineamento utilizado foi o quadrado latino 4 x 4, em que os tratamentos consistiram em níveis de 0, 33, 67 e 100% de substituição do milho pela farinha de varredura. Os tratamentos não influenciaram a ingestão, excreção fecal, digestão total e a digestibilidade total da MS, MO, PB, FDN e carboidratos não-fibrosos (CNF). Houve diminuição linear na excreção fecal e aumento na digestibilidade do amido, com a inclusão da farinha de mandioca de varredura. O NDT não diferiu entre as dietas estudadas, com média de 71,59%. Houve correlação positiva entre a digestibilidade da matéria orgânica (DIGMO) e o NDT (r = 0,9472), permitindo estimativas do NDT a partir da equação NDT (%) = 0,8897DIGMO (%) + 10,9940 (R 2 =0,8972). A substituição da farinha da mandioca de varredura não alterou a produção, bem como a composição do leite. Recomenda-se a utilização da farinha de mandioca de varredura em dietas de cabras em lactação, em total substituição ao milho, sem prejuízos na digestibilidade dos nutrientes e na produção.Palavras-chave: cabras leiteiras, mandioca, NDT, produção de leite, subproduto Corn Replacement by Cassava by-Product Meal in the Lactating Goat Diets: Effects on Milk Production and Composition and Nutrients DigestibilityABSTRACT -The objectives of this work were to evaluate effects of replacing corn by cassava by-product meal, in diets of Saanen lactating goats, on milk production and composition (total solids and crude protein), nutrient apparent digestibility and total digestible nutrients (TDN) of diets. Four multiparous goats fitted with ruminal cannula, with 100 days of lactation, were used. The design was a 4 x 4 Latin square and treatments as following: 0, 33, 67 and 100% replacement of corn by cassava by-product meal. Treatments did not affect intake, fecal flow and dry matter (DM), organic matter (OM), crude protein (CP), neutral fiber detergent (NDF) and non-fiber carbohydrate (NFC) total digestion (AD) and total digestibility (DIG). There was a linear fecal flow decrease and a starch digestibility increase with cassava by-product meal inclusion. TDN did not differ among diets with an average of 71.59%. There was a positive correlation (r = 0.9472) between OMDIG and TDN, making possible TDN estimation from the equation: TDN (%) = 0.8897OMDIG (%) + 10.9940 (R 2 = 0.8972). Cassava by-product inclusion did not affect milk production and composition (total solids and crude protein). These results permit to recommend inclusion of cassava by-product in goat lactating diets, in total replacement o...

We measured the effects of the addition of tannic acid on chemical composition and crude protein (CP) ruminal degradability of bermudagrass, cv. coast cross (Cynodon dactylon L.) and alfalfa (Medicago sativa L.) silages with nylon bags incubated in the rumen of two fistulated lactating cows. Silage pH was greater for alfalfa than for bermudagrass. The addition of tannic acid had no effect on silage pH. Ammonia N was greater in alfalfa than in bermudagrass silage. Treated and control silages had similar ammonia N concentrations. The percentage of CP that was solubilized at time 0 was lower for alfalfa than for bermudagrass silage. The addition of tannic acid decreased the portion of CP solubilized at time 0 and increased the potentially degradable fraction of CP. The potentially degradable fraction of CP was greater for alfalfa than for bermudagrass. There was an interaction of species and treatment; the disappearance rate of CP increased with tannic acid treatment of alfalfa but decreased with acid treatment of bermudagrass. The effective degradability of CP was similar for control and treated alfalfa but lower for treated than for control bermudagrass. Tannic acid treatment is effective in decreasing the rapidly soluble fraction of alfalfa and bermudagrass silages, which could be beneficial to the animal because it would decrease the excess of N in the rumen after feeding. Tannic acid treatment decreased CP degradability of bermudagrass silage but had no effect on alfalfa silage, suggesting that tannic acid concentration required to effectively decrease CP degradability differs among forages.

S. 2005. Milk production and milk composition of dairy cows fed Lac100 ® or whole flaxseed. Can. J. Anim. Sci. 85: 413-416. Cows were fed whole flaxseed or calcium salts of soybean oil as a fat source. Cows fed flaxseed had lower (P < 0.01) milk yield and higher (P < 0.01) percentages of fat and protein than cows fed calcium salts. Feeding whole flaxseed and calcium salts of soybean oil increased, respectively, the concentrations of alpha-linolenic acid and conjugated linoleic acid in milk.