Maurílio José Alvim

Avaliação de gramíneas forrageiras na região sul de Minas Gerais

experiments were undertaken in the South region of Minas Gerais State, Brazil, to evaluate the yield potential of forage grasses. In experiment 1, the following species, considered as having low nutritional requirements, were evaluated: Andropogon gayanus, Kunt; Brachiaria brizantha, Stapf; Brachiaria decumbens, Stapf; Brachiaria ruziziensis, Germain Evrard; Brachiaria humidicola (Rendle) Schweickt and Melinis minutiflora, Beauv. In experiment 2, the species considered as having medium and high nutritional requirements, that is: Setaria sphacelata (Schum.); Hemarthria altissima, (Poir.) Stapf; Chloris gayana, Kunt; Cynodon nlemfuensis, Vanderyst var. nlemfuensis; Hyparrhenia rufa, (Ness) and the cultivars Panicum maximum, Jacq.: Tobiata, Green Panic and Makueni were evaluated. The experimental design used was randomized blocks with three replications. Rates of lime and of fertilizers for both establishment and maintenance differed between experiments. Each grass was evaluated for the following atributes: forage yield and crude protein content in the dry and wet season and ground cover. In experiment 1, the grasses with outstanding performance were B. brizantha, B.decumbens and A. gayanus, while in experiment 2 the species having the highest forage yield potential were: S. sphacelata, P. maximum cv. Tobiata.

Resposta do tifton 85 a doses de nitrogênio e intervalos de cortes

This experiment was carried out at Embrapa-Centro Nacional de Pesquisa de Gado de Leite, located in Juiz de Fora, MG, Brazil, from October, 1995 to October, 1997, to evaluate the effects of five N doses (0, 100, 200, 400 and 600 kg/ha/year) and three cutting intervals (two, four and six weeks, during the rainy season, and four, six and eight weeks, during the dry season) on dry matter production and crude protein content of tifton 85. Data were analyzed as randomized blocks design in split-plot, with three replicates. The annual dry matter yield increased up to the highest dose of 600 kg/ha/year of N fertilization and up to four weeks cutting interval, during rainy season, and six-week cutting intervals, during the dry season. The highest production of dry matter was 23.1 ton/ha/year, of which 17.8 ton/ha were obtained in the rainy season. The lowest production was 2.6 ton/ha/year, of which 1.9 ton/ha were obtained in the rainy season. Crude protein content varied inversely with cutting intervals and as the amount of N fertilization increased up to dose of 600 kg/ha/year. The crude protein contents did not differ significantly with cutting intervals during the raining season. The highest level of crude protein obtained was 21.7%. Tifton 85 persistency was hampered in the absence of N fertilization and the shortest cutting interval.

Evaluation under grazing of forage potential of Cynodon grass under two nitrogen and potassium levels

The study was undertaken in Coronel Pacheco - MG (National Dairy Cattle Reserch Center of the Brazilian Agricultural Corporation - EMBRAPA), to evaluate, under grazing conditions, the Cynodon nlenfuensis, Vanderyst and three cultivars of Cynodon dactylon, L. Pers. (Florona, Florakirk, Florico), fertilized with either 250:200 or 500:400 kg/ha/year of N:K2O. The experimental design was a randomized blocks, in split-plot, and three replications. No significant difference on dry matter yield between the two rates of N/K2O were found. In both N:K2O rates, Florakirk cultivar presented the highest annual dry matter yield, however, in the dry season it showed a low yield level. The Florico was the cultivar with the lowest dry matter yield. The best and the worst forage distribution were exhibited by cultivars Florona and Florakirk, respectively. The CP contents in the forage was not influenced by either nitrogen rates or season, and directly related to the leaf-stem ratio. The highest CP contents were found in Florakirk, while the lowest in african stargrass grass and Florico cultivar. The IVDMD of forage produced during the rainy season was slightly superior to those of the dry season. The N:K2O rates did not influence IVDMD, which were higher in Florakirk and Florona cultivars.The study was undertaken in Coronel Pacheco – MG (National Dairy Cattle Reserch Center of the Brazilian Agricultural Corporation – EMBRAPA), to evaluate, under grazing conditions, the Cynodon nlenfuensis, Vanderyst and three cultivars of Cynodon dactylon, L. Pers. (Florona, Florakirk, Florico), fertilized with either 250:200 or 500:400 kg/ha/year of N:K2O. The experimental design was a randomized blocks, in split-plot, and three replications. No significant difference on dry matter yield between the two rates of N/K2O were found. In both N:K2O rates, Florakirk cultivar presented the highest annual dry matter yield, however, in the dry season it showed a low yield level. The Florico was the cultivar with the lowest dry matter yield. The best and the worst forage distribution were exhibited by cultivars Florona and Florakirk, respectively. The CP contents in the forage was not influenced by either nitrogen rates or season, and directly related to the leaf-stem ratio. The highest CP contents were found in Florakirk, while the lowest in african stargrass grass and Florico cultivar. The IVDMD of forage produced during the rainy season was slightly superior to those of the dry season. The N:K2O rates did not influence IVDMD, which were higher in Florakirk and Florona cultivars.

Cultivares de alfafa em área de influência da Mata Atlântica no Estado de Minas Gerais

Este trabalho teve como objetivo avaliar o potencial forrageiro de cultivares de alfafa ( Medicago sativa L.) em area de influencia da Mata Atlântica no Estado de Minas Gerais. Foram avaliadas 30 cultivares de alfafa em delineamento de blocos ao acaso com tres repeticoes. As sementes foram infectadas com a estirpe de Rhizobium melilotii BR 7407. No periodo das chuvas e da seca houve diferencas significativas entre as cultivares quanto ao potencial de producao de forragem, relacao folha/caule e tolerância a pragas e doencas. Quanto ao teor de proteina bruta, houve diferencas significativas entre as cultivares, somente no periodo das chuvas. As cultivares que se destacaram na maioria dos parâmetros avaliados foram a Crioula, P30, Monarca e Florida 77. As maiores producoes de forragem nas estacoes das chuvas e da seca foram obtidas pela cultivar Crioula, constituindo, assim, boa opcao para o cultivo da alfafa na Zona da Mata de Minas Gerais.

Estratégia de fornecimento de concentrado para vacas da raça Holandesa em pastagens de coast-cross

The trial was carried out at the Embrapa-Centro Nacional de Pesquisa de Gado de Leite, at Coronel Pacheco, Brazil, to evaluate two ways of feeding 6 kg/day of a concentrate mixture to cows grazing a coast-cross pasture: A - a fixed amount, and B - a variable amount (9, 6 and 3 kg/cow/day for the first, second, and third stage of lactation). A randomized block design was used with two replications for land grazing area, with the treatments organized in split plots. In the plots, the ways of feeding of distributing the ration concentrate were considered, and in the split plots, the phases of lactation were used. Feeding variable amount of concentrate affected (P 0.05), 93.1 (±10.8) and 94.8 (±10.9) kg/ha (P > 0.05) in the second phase; 14.2 (±2.2) and 13.4 (±2.3) kg/cow (P > 005) and 102.2 (±12.4) and 93.8 (±10.5) kg/ha (P > 0.05) in the last phase, respectively for A and B. The variable dose was the best indicated to supplement Holstein dairy cows in coast-cross pasture.

Efeito de diferentes períodos de ocupação da pastagem de capim-elefante sobre a produção de leite

Elephant grass (Pennisetum purpureum Schum. cv. Napier) pastures were grazed by lactating dairy cows with the aim of assessing the best grazing period to maximize milk production. Three grazing periods (1, 3 and 5 days, with 30 days resting) were tested using a randomized block design, with two replications, during three years. Each paddock was grazed by 4 milking cows. During the experimental period, the cows received individually 2,0 kg/day of a concentrate mixture. Esti- mates of forage availability and quality, plant height, ground cover and milk production, were re- corded. Results showed that available forage and quality and milk production were not influenced by the three different grazing periods. Average milk production/cow/day in the rainy season were 10.9, 10.8 and 10.8 kg and the average milk yields per hectare were 7,848, 7,800 and 7,776 kg/ha for 1, 3 or 5 grazing days, respectively (P>0.05). The largest flotations in dairy milk yield per cow occurred in the five grazing days treatment, explained for both forage availability and quality decreases along the grazing period on each paddock.

Utilização de soja integral tostada na dieta de vacas em lactação, em pastagem de coastcross (Cynodon dactylon, L. Pers.)

The purpose of this study was to evaluate the effect of the inclusion of roasted whole soybean (RWS) in the concentrate composition to be employed to supplement feeding of Holstein cows on coastcross-1 pasture. Twelve early-lactating cows were utilized, divided into two groups as follows: A) the ones fed standard concentrate (control) containing soybean meal (23.5% CP and 80% TDN) and B) the ones fed RWS-enriched concentrate (19.5% CP and 86% TDN). In two treatments, daily feeding was of 9 kg/cow of concentrate. An electric fence was utilized for helping pasture management, which was based on rotational grazing, with one day of paddock occupation and a resting period of 25 days. The experiment lasted 100 days, during the summer, when the pasture was fertilized with 140, 32, and 112 kg/ha of, respectively, N, P2O5 and K2O, divided into four applications. The inclusion of RWS caused an increase in milk production and in fat-corrected (to 3.5%) milk production, which were, in average: 22.2 and 23.6 and 19.8 and 19.7 kg/cow/day, for RWS-enriched and control treatments, respectively. The milk fat levels were 4.16 and 3.49% in the plots, where animals were fed, respectively, RWS-enriched and standard concentrate. The cows fed RWS-enriched concentrate exhibited superior milk production than the ones fed standard concentrate, reaching 145.4 kg milk/ha/day. In both treatments the cows showed weight gains.