Armando de Andrade Rodrigues

Efeito do tratamento com aditivos químicos e inoculantes bacterianos nas perdas e na qualidade de silagens de cana-de-açúcar

Objetivou-se avaliar a eficacia de aditivos quimicos e inoculantes bacterianos na inibicao da producao de etanol, na diminuicao das perdas de MS e na melhoria da digestibilidade in vitro de silagens de cana-de-acucar. Foram testados os seguintes tratamentos (doses com base na materia natural): sem aditivos - controle; UR - ureia (0,5; 1,0; 1,5%); NaOH - hidroxido de sodio (1,0; 2,0; 3,0%); PROP - propionato de calcio (0,05; 0,1; 0,2%); BENZ - benzoato de sodio (0,05; 0,1; 0,2%); SORB - sorbato de potassio (0,015; 0,03; 0,045%); PLA - Lactobacillus plantarum (1 x 106 ufc/g); BUCH - Lactobacillus buchneri (3,64 x 105 ufc/g); PLA/UR 0,5% - L. plantarum combinado com 0,5% de ureia; PLA/UR 1,0% - L. plantarum combinado com 1,0% de ureia. A ensilagem foi realizada em baldes plasticos de 20 L adaptados com valvulas para eliminacao de gases e dispositivo para coleta de efluentes. Os dados foram coletados aos 90 e aos 180 dias apos a ensilagem. Nenhum dos aditivos foi capaz de reduzir a concentracao de etanol nas silagens. Os tratamentos PROP 0,1% e PLA causaram aumento no teor de alcool em relacao a silagem controle (4,8 e 12,5% vs 3,8% da MS, respectivamente). Os tratamentos UR, NaOH, SORB-0,03%, BUCH, PLA/UR 0,5% e PLA/UR 1,0% reduziram a perda total de MS. As silagens tratadas com ureia, hidroxido de sodio, benzoato de sodio e sorbato de potassio 0,045% apresentaram maior digestibilidade in vitro da MS em comparacao a silagem controle.

Influência de polimorfismos genéticos sobre os parâmetros da curva de crescimento em bovinos de corte

ABSTRACT - Records of the weights at birth, weaning and monthly from 8 to 19 months of age from three genetic groups: ½Canchim-Nellore (CN), ½Angus-Nellore (AN) e ½Simmental-Nellore (SN), born in 1998 and 1999 in Southeast Brazil, were used to fit a Logi sticnonlinear model that included the fixed effects of the contemporary group and genotype of the genes kappa-casein- Hinf I (CSN3): AAand AB, growth hormone- Alu I (GH): LL and LV, and β-lactoglobulin- Hae III (LGB): AA, AB and BB, to examine the effect of thesemarkers on the growth curve. The Logistic model used to explain the growth of the CN, AN and SN genetic groups, was influenced bythe genotypes of the CSN3, GH e LGB markers. The major differences started at 12-13 months of age. The value of the maturing ra te( k ) of the AA genotype for CSN3 was superior in relation to AB genotype in the CN, AN and SN genetic groups. However, there wasobserved small difference in estimate of the asymptotic value ( A ) for the AA and AB genotypes in CN and SN genetic groups. For theGH polymorphism there were inferior values of the parameters

Aditivos químicos e inoculante bacteriano na ensilagem de cana-de-açúcar: efeitos sobre a fermentação das silagens e o desempenho de garrotes

Os objetivos neste experimento foram avaliar o desempenho de tourinhos alimentados com racoes completas preparadas com silagens de cana-de-acucar tratadas ou nao com aditivos e estudar o efeito dos aditivos sobre a fermentacao das silagens. Trinta tourinhos Canchim com peso medio de 312 kg foram distribuidos em delineamento de blocos casualizados para avaliar tres tipos de racoes isoproteicas e isoenergeticas (relacao volumoso:concentrado de 35:65): racao com silagem sem aditivo (controle); racao com silagem tratada com ureia (5 g/kg de materia verde, MV) + benzoato de sodio (0,5 g/kg de MV); racao com silagem inoculada com Lactobacillus buchneri (5 × 104 ufc/g de MV). As silagens apresentaram pH adequado a conservacao ( 53 g/kg de MS). Na silagem tratada com ureia + benzoato e na silagem inoculada, os teores de etanol foram mais baixos em relacao a silagem sem aditivo (43; 73 e 92 g/kg de MS, respectivamente). A silagem com ureia + benzoato apresentou teores mais elevados de proteina bruta e de nutrientes digestiveis totais em comparacao as outras silagens. O tipo de racao nao afeta o ganho de peso vivo (1,75 kg PV/dia) nem a ingestao de MS (10,5 kg MS/dia), mas a conversao alimentar foi melhor nos animais que receberam a racao controle em relacao aqueles alimentados com a racao com silagem inoculada (5,71 vs 6,45 kg MS/kg GPV).

Efeito do teor protéico do concentrado no consumo de cana-de-açúcar com uréia e ganho de peso de novilhas em crescimento

The effect of different protein supplements on intake of sugar cane with urea by crossbred Holstein-Zebu heifers was evaluated during 12 weeks in the dry season. Eighteen heifers, averaging initial weight of 288 kg and age ranging from 15 to 22 months, were supplemented with soybean meal or concentrate with 28.7% crude protein. The amount of supplement fed was 1.0 kg/ animal·day. Sugar cane with urea was fed ad libitum. The average intake of dry matter and neutral detergent fiber of sugar cane with urea in percent of live weight were 2.33 and 2.43; 1.19 and 1.23 for the animals supplemented with soybean meal or concentrate with 28.7% crude protein, respectively. The protein supplements did not affect intake of dry matter and neutral detergent fiber of sugar cane with urea. The supplements did not affect heifers weight gain. The average daily weight gains were .39+.04 and .36+.04 kg/animal·day for animals supplemented with soybean meal or with concentrate containing 28.7% crude protein, respectively.

Fermentation parameters, quality and losses in sugarcane silages treated with chemical additives and a bacterial inoculant

The objective of this trial was to evaluate chemical additives and a bacterial inoculant on the inhibition of alcoholic fermentation and reduction of losses in sugarcane silages. Treatments were (doses on a fresh forage basis): without additive (control); urea (10 g/kg); urea (5 g/kg) + sodium benzoate (0.5 g/kg); sodium benzoate (1 g/kg); urea + ammonium sulfate in a 9:1 relation (10 g/kg); Lactobacillus buchneri (5 × 104 cfu/g). Silages were produced in 10.16- × 30-cm PVC tubes, provided with tight lids adapted with Bunsen valves for gas losses quantification. Minisilos were opened 139 days after ensiling. Ethanol content (227 g/kg dry matter - DM) and total DM loss (30%) were high in the control silage. All additives, except benzoate, decreased ethanol concentration in silages. Inoculation with L. buchneri increased acetic acid content in the silage, resulting in a 41% reduction in ethanol content and the lowest gas loss among treatments (15.2%). There was synergistic effect between additives for the combined use of urea and benzoate. Silage treated with urea + ammonium sulfate has higher content of total digestible nutrients than the silage treated with urea exclusively.

Desempenho de bezerros da raça Nelore e cruzados desmamados recebendo concentrado em pastagem adubada de Cynodon dactylon cv. Coastcross

In three years of research, 223 purebred Nelore and crossbred Canchim × Nelore, Angus × Nelore and Simmental × Nelore calves received either mineral mixture or 3 kg/animal/day of a concentrate, containing 18.8% crude protein and 81.5% total digestible nutrients, on a dry basis, while in a rotational grazing of Cynodon dactylon cv. Coastcross, fertilized pastures. Available forage (kg dry matter/ha) was different for paddocks of cattle receiving mineral mixture (2,961 kg) from those receiving concentrate (3,383 kg). However, forage dry matter allowance was higher (9.9 kg/animal/day or 3.9% of BW) for cattle receiving mineral mixture than for cattle receiving concentrate in the diet (9.0 kg/animal/day or 3.3% of BW). Available forage had, on a dry basis, 13.6% crude protein, 79.8% neutral detergent fiber, 62.3% in vitro dry matter digestibility, 3.9 g/kg Calcium, 2.0 g/kg magnesium, 2.5 g/kg phosphorus, 22.7 g/kg potassium, 2.8 g/kg sulfur, 9.9 mg/kg copper, 22.5 mg/kg zinc, 98 mg/kg manganese and 188 mg/kg iron. Statistical interactions of genetic group × supplementation and year × supplementation were observed for average daily gain and for stocking rates while a grazing cycle × supplementation interaction was observed for stocking rates. The average daily gain of Nelore, Canchim × Nelore, Angus × Nelore and Simmental × Nelore, receiving mineral mixture in the diet, were 0.48, 0.63, 0.68 and 0.50 kg, respectively, while those animals receiving concentrate in the diet, were 0.87, 0.95, 0.99 and 0.95 kg, in the same order of genetic groups. Average stocking rates of pastures grazed by all genetic groups receiving mineral mixture in the diet was 6.1 animal units/ha, while the pastures grazed by Nelore, Canchim × Nelore, Angus × Nelore and Simmental × Nelore showed values of 7.5, 7.6, 8.8 and 9.0 animal units/ha, respectively, for animals receiving concentrate in the diet. The genetic group affects performance of cattle grazing coastcross and shows interaction with supplementation of diet with concentrate.

Efeito do pastejo restringido em aveia sobre a produção de leite

The objective of this research was to evaluate the effect of oat (Avena sp.) restricted grazing on milk production. Twelve crossbred dairy cows (holstein-zebu) were used in a complete randomized block design. The cows were allocated to two treatments: A. restricted grazing on oat (3 hours day-1) plus 10 kg of corn silage; B. corn silage ad libitum as the only forage. All animals received 5.0 kg of concentrate head-1 day-1 with 19% crude protein (CP) and 75% total digestible nutrientes (TDN). There was no statistical difference (P > 0.05) between A and B treatments in milk production (14.6 vs. 13.3 kg cow-1 day-1). Difference was found (P < 0.05) in fat content (3.4 vs 3.8%), but this did not affect (P < 0.05) 4% milk corrected production. Difference was found also in weight gain (P < 0.08). The cows that had access to restricted grazing on oat gained 0.53 kg day-1 and the cows that received corn silage as the only forage gained 0.25 kg day-1. It was concluded that restricted grazing on Sao Carlos oat cultivar allow high milk production with crossbred cows.

Performance of dairy cows fed rations produced with sugarcane silages treated with additives or fresh sugarcane

Um experimento foi realizado com o objetivo de avaliar o desempenho de vacas leiteiras alimentadas com silagens de cana-de-acucar tratadas com aditivos em comparacao ao de vacas alimentadas com a forragem fresca. Vinte e quatro vacas holandesas foram agrupadas em blocos de tres vacas, de acordo com a ordem do parto e com o nivel de producao de leite, em um delineamento quadrado latino multiplo 3 x 3, para avaliacao de tres tipos de racao (63% volumoso e 37% concentrado na materia seca - MS): racao com silagem tratada com ureia (5,0 g/kg de materia verde - MV) + benzoato de sodio (0,5 g/kg MV); racao com silagem inoculada com Lactobacillus buchneri (5 x 104 ufc/g MV); racao com cana-de-acucar fresca. Cada periodo de avaliacao foi composto de duas semanas de adaptacao e uma semana de coleta de dados. As vacas alimentadas com as racoes com silagens tratadas com ureia + benzoato e com L. buchneri tiveram menor consumo de materia seca (18,5 vs 21,4 kg/dia) e menor producao de leite (17,4 vs 18,6 kg/dia) em comparacao aquelas alimentadas com a racao com forragem fresca. O teor de gordura no leite das vacas que receberam silagem inoculada com L. buchneri foi mais alto que no daquelas alimentadas com forragem fresca, o que resultou em valor de producao de leite corrigida para 3,5% de gordura (LCG) similar entre os grupos. As vacas que receberam racao com silagem tratada com ureia + benzoato apresentaram nivel intermediario de gordura no leite, mas producao inferior de leite corrigida em comparacao as alimentadas com cana fresca. A eficiencia alimentar (kg LCG/kg MS consumida) foi mais alta nas vacas alimentadas com a racao produzida com silagem inoculada (0,95), intermediaria para as vacas que receberam silagem tratada com a combinacao de aditivos quimicos (0,91) e mais baixa para as vacas alimentadas com a cana-de-acucar fresca (0,83).

Diurnal behavior of dairy cows on alfalfa pastures supplemented with corn silage and concentrate

Avaliou-se o comportamento ingestivo de vacas leiteiras com acesso restrito ou irrestrito a uma pastagem de alfafa suplementada com silagem de milho e concentrado. Utilizaram-se 16 vacas da raca Holandesa, em estadio medio de lactacao, em delineamento em blocos ao acaso. Os tratamentos foram: silagem de milho substituida parcialmente por pastejo restrito ou irrestrito de alfafa. As vacas foram manejadas em sistema de pastejo rotacionado e a quantidade de concentrado foi igual em ambos os tratamentos. As atividades comportamentais observadas foram pastejo, ruminacao e ocio, das oito as 19 horas, em quatro ocasioes. No pastejo irrestrito, observou-se que, nos horarios entre 14 e 17 horas, o pastejo foi intermitente e de curta duracao, enquanto no pastejo restrito a atividade de pastejo foi mais prolongada durante a manha e no final da tarde. A restricao no tempo disponivel para pastejo da alfafa influenciou marcadamente a distribuicao, no decorrer do dia, do tempo gasto em pastejo, da ruminacao e do ocio. Entretanto, nao se observou este efeito no tempo total gasto nestas atividades.

Causas de variação da produção de leite em um rebanho da raça Holandesa em São Carlos, SP

The objective of this work was to evaluate the effects of year of calving (YC), season of calving (SC), genetic group (GG), calf sex (SEX), reason for drying-off (RD), cow age at calving (AGE, in months), lactation length (LL, in days) and sire (SIRE) on milk yield (MY) in a Holstein breed herd. A total of 684 observations, from 267 cows raised in a physical models of dairy cattle production system maintained at Embrapa - Centro de Pesquisa de Pecuaria do Sudeste, Sao Carlos, SP, was included in the analysis. Data on milk yield were collected from October 1984 to December 1993 and analyzed by the least-squares method through a mathematical model including the fixed effects of YC, SC, GG, SEX and RD, linear and quadratic effects of AGE and LL as covariates and the random effect of SIRE. There were effects of YC, SC, RD, AGE (linear and quadratic), LL (linear and quadratic) and SIRE on MY. GG and SEX did not influence MY. In the studied period, there was a linear increase of MY in 347.6±22.02 kg/lactation.year. The cows freshening in the summer (January-March) were less productive (MY = 4,325±82 kg) than those freshening in the other seasons of the year (4,795±49 kg). The cows with lactations terminated because of pre-calving presented higher MY (4,903±78 kg) than those with lactations terminated because of low production/other reasons (4,452±61 kg). The MY was influenced by linear (18.86±2.39 kg/mo.) and quadratic (-0.2934±0.0456 kg/mo2) effects of AGE. There were linear (15.83±0.41 kg/day) and quadratic (-0.0057±0.0023 kg/day2) effects of lactation length on MY.