Adaptation to high-energy diets of cannulated nellore cattle previously submitted to either nutritional restriction or intake of concentrate feedstuffs on rumen fermentation patters and microorganisms profile
The objective of this study is to evaluate the effect of diet restriction or prior exposure to concentrate ingredientes priorto the adaption period to high concentrate diet on parameters ruminal fermentation patterns and ruminal microorganisms profile of cannulated Nellore cattle. Six Nelore steers will be used, with initial body weight about 350 kg, 20 months and cannulated in the rumen, which will be divided into two Latin squares 3 x 3. The treatments will differ only with respect to the type of diets prior to the adaptation period: Maintenance (forage ad libitum + mineral supplement); Restriction (forage restricted to 1.4% of body weight + mineral supplement) and concentrate (forage ad libitum + 0.5% of the body weight of concentrated ingredients + mineral supplement). The study will last 110 days, in which animals will be submitted to three experimental periods (30 days each one) and two washout intervals (10 days) between the periods 1 and 2, 2 and 3; each period will be divided as follows: 14 days of pre-adaptation, 6 days of adaptation 1 (72% concentrate), 6 days of adaptation 2 (79% concentrate) and 4 days of finishing diet (88% concentrate). The rumen pH and temperature will be monitored through the use of data loggers it will be evaluated the rumen production of short chain fatty acids, ammonia and lactic acid concentration; the relative quantification of cellulolytic, amylolytic and lactate bacteria utilizing PCR and total and differential quantification of protozoa. Thus, the hypothesis is to test if Nelore cattle exposed to feed restriction or comsuption of concentrate ingredientes prior to the adaptation period present same rumen fermentation patters and microrgaganism profile when compared to animals fed to maintenance.
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