Microbial and fermentation profiles, losses and chemical composition of silages of buffel grass harvested at different cutting heights

The present study evaluated the microbial population, fermentation profile, losses and dry matter recovery, and chemical composition of silages of buffel grass at different cutting heights. To evaluate the microbial fermentation dynamics, the treatments resulted from a 4 × 5 factorial combination consisting of 4 cutting heights and 5 fermentation periods, in a completely randomized design with three replications. The fermentation was evaluated at the end of 1, 3, 7, 15 and 30 days. The other characteristics of silages with 30 days were evaluated following a completely randomized design with four treatments, consisting of 4 cutting heights (30, 40, 50 and 60 cm), and five replications. Fermentation period and cutting height effects and interaction between both factors were observed on the populations of lactic acid bacteria (LAB), enterobacteria and molds and yeasts. The peak of development of LAB populations was observed on the seventh day of fermentation for the heights of 40 and 50 cm, with 8.25 and 8.30 log cfu/g, respectively. The pH values of silages ranged with different cutting heights, in which at the height of 50 cm the decrease was most pronounced. However, the pH values were similar between the cutting heights at the end of 30 days of fermentation. Quadratic relationship was observed between lactic acid concentrations and cutting heights. The crude protein content behaved linearly, initially showing 128.5 g/kg DM at 30 cm, decreasing as the cutting heights increased. The neutral detergent fiber and ether extract contents increased linearly with the cutting heights. Based on microbial populations, fermentation, losses and chemical composition, it is recommended to harvest buffel grass for silage from 50 cm on

Matointerferência em arroz de sequeiro. I: efeitos do espaçamento e da adubação nitrogenada nas concentrações de nutrientes no arroz e nas plantas daninhas

O trabalho insere-se num estudo global sobre os efeitos do espaçamento entre sulcos de semeadura e da dose de adubação nitrogenada sobre as relações competitivas entre a cultura do arroz de sequeiro (Oryza sativa L.) e uma comunidade de plantas daninhas. Para tanto, os tratamentos foram dispostos num esquema fatorial 2x2x3, onde constituiram variáveis: duas condições de manejo da comunidade infestante - sem controle e com controle do mato durante todo o ciclo do arroz - dois espaçamentos entre sulcos de semeadura - 0,40 e 0,60 m - e três doses de nitrogênio - 2,4, e 7,2 de N/m de sulco. O experimento foi montado sobre solo Latossolo Vermelho Escuro fase arenosa e obedeceu o delineamento experimental de blocos ao acaso com 4repetições. Foram realizadas duas avaliações: por ocasião do perfilhamento e por ocasião do florescimento da cultura. em comparação com as plantas daninhas, os teores de N, P, Fe, Mn e Zn foram mais elevados no arroz; os de Ca e Mg foram menos elevados e os teores de K e Cu foram inferiores aos de D. horizontalis e superiores aos de 7. hirsuta. Por ocasião do florescimento, o arroz apresentou teores mais elevados de P, Cu, Mn e Zn, enquanto que a comunidade infestante apresentou maiores teores de N, K, Ca, Mg e Fe. Os efeitos do espaçamento e da fertilização nitrogenada apresentaram aspectos distintos de acordo com o nutriente, a espécie envolvida e a época da avaliação. de um modo geral, os efeitos das plantas daninhas foram mais acentuados no espaçamento de 0,60 m.The essay insered in a global study about the spacing and nitrogen rate effects on the competitive relationship between weeds and upland rice crop. The treatments were located in a factorial desing 2x2x3 , when the variables were: two weed managment conditions - weeded and not weeded during all rice cycle - two row spacing - 0.40 and 0.60, e three nitrogen rate - 2.4 , 2.8 and 7.2 g de N/m of row. The essay was installed on Latossolo Vermelho Escuro sandy phase soil. Two valuations were realized: the first in the crop tillerinq and the second in the crop flowering. In the tillering phase the most important weed were Digitaria horizontalis and Indigofera hirsuta. The first weed showed higher contents of K, Mg, Fe and Mn and lower contents of N and Ca than the legumonosous weed. In comparison with the weeds, the rice contents of N, P, Fe, Mn and Zn were higher, the contents of Ca and Mg were lower. The K and Cu rice contents were lower than in D.horizontal in and higher than in l.hirsuta. In the flowering phase, the rice showed higher contents of P, Cu, Mn and Zn and lower contents of N, K, Ca, Mg and Fe, than the weed community. The row spacing and nitrogen rate effects showed different aspects, in according with the nutrient, weed especie and valuation period. In general, the weed effects were more drastics on the 0.60 m row spacing

Crop quality, storage, and utilization

xii+276hlm.;23c

Crop quality, Storage, and utilization/ Edit: Hoveland C.S.

xii, 276 hal.: ill.; 25 cm

Crop quality, Storage, and utilization/ Edit: Hoveland C.S.

xii, 276 hal.: ill.; 25 cm

Introduction and acceptance of novel endophyte tall fescue in the USA

Release of the cultivar 'Kentucky 31' in 1943 led to widespread planting of tall fescue in the USA. An endophytic fungus (Neotyphodium coenophialum) usually present in this grass produces compounds that enhance competitiveness and survival of tall fescue in many environments, but it also produces ergot alkaloids implicated in the cause of animal disorders. Screening of hundreds of fungus strains identified some that do not produce high levels of ergot alkaloids. A "novel" endophyte strain was inserted into University of Georgia-developed cultivars 'Georgia 5' and 'Jesup' and became commercially available under the name MaxQTM in 1999. It is estimated that at present there are some 121,000 hectares of novel endophyte tall fescue in at least 35 USA states. Persistence has been good and animal performance has been excellent. It is expected that novel endophyte tall fescue area will continue to increase in the USA in the future. Keywords: novel endophyte, tall fescue, Neotyphodium, MaxQTM</jats:p

Animal performance, carcass quality and economics of cattle finished after grazing endophyte-infected, endophyte-free or nonergot alkaloid-producing endophyte-infected tall fescue

Angus-cross steers grazed wild type endophyte-infected (E+), nonergot alkaloid-producing endophyte-infected (AR542), or endophyte-free (E-) tall fescue pastures at two locations. Twenty-four animals per location were transported to a research feedlot after the completion of the grazing phase and fed for 100 d. Grazing average daily gain (ADG) was 0.47 kg/d greater (P=0.001) for cattle grazing AR542 than those grazing E+ pastures. In the feedlot, overall ADG did not differ among AR542 and E+ (P=0.40) or AR542 and E- (P=0.19), and averaged 2.09 + 0.15 kg/d across all treatments. Feed efficiency was greater (P=0.02) for E+ than AR542. Hot carcass weight was 40 kg greater (P=0.01) for AR542 than E+. Other carcass traits did not differ (P≥0.10) among treatments. Net present values (NPV) were $177.08/ha for E- and$336.76/ha for AR542 compared to E+. Keywords: beef, endophyte, carcass</jats:p