Rumen escape protein in concentrate ingredients determined with the nylon bag and enzymatic techniques

Rumen escape protein (REP) was determined for 26 concentrate feed ingredients using the nylon bag technique and in vitro using a proteolytic enzyme preparation of Streptomyces griseus. In vitro, the samples were incubated for 0, 1, 6 and 24 h. The highest correlation was observed between percentage REP (%REP), determined with the nylon bag technique, and the in vitro undegradable fraction after 1 h of incubation (%U1) (R2= 0.77). Longer incubation times weakened the relationship. %REP could be estimated from %U1 according to: %REP = -0.76 (±5.99) + 0.81 (±0.09) × %U1. The 0 h incubation, representing in vitro solubility, had a relationship (R2 = 0.67) with in situ %REP, suggesting that %REP is mainly determined by crude protein (CP) solubility and to a lesser extent by degradation. © 2002 Elsevier Science B.V. All rights reserved

The performance of young pigs fed different amounts of marigold (Calendula officinalis) meal; a pilot study

Hexane-extracted calendula meal was tested in an acceptance trial with pigs to determine their response to calendula meal. Performance parameters included feed intake, daily growth and post mortem histopathological examination of vital organs. Although calendula meal showed potential as a ration ingredient for young pigs it is advised not to include more than 10% of it in the die

The effects of substrate, ammonia and pH on gas production and starch degradation from starchy feedstuffs in buffered rumen fluid

Three experiments were conducted to evaluate effects of pH,substrate and ammonia levels on starch degradation (STAD) and on gas production to look into the optimal conditions for GP technique in starchy feedstuff evaluation. The pH effect on STAD of six starchy samples was studied by using phosphate buffer mixed with rumen liquor in 24-h in-vitro incubation. The results indicated p H5 adversely affected STAD and no significant differences were found among p H7, 6and 5.5, even though STAD appeared larger at p H6. The ranking in STAD degree of the starchy feedstuffs was found in vitro degradation with rumen fluid at all p Hlevels. Barley, wheat and tapioca showed the highest STAD and potato starch and maize the lowest in STAD at each pH level. Minimum STAD took place in first 4-h incubation. Sub-strate level did not affected total GP (g-1OM), but influenced total GPper incubated bottle. On the other hand, substrate concentration significantly affected the shape of gas curve. Increased substrate reduced the time to reach the half-maximal gas production and curve sharpness.Thus substrate concentration affected the fermentation rate, and higher increased substrate concentration increased GP rate in the OM range of 100 500mg substrate. Ammonia carbonate concentration (ACC) did not affected total GP (g-1OM) in such starchy feedstuffs, but it affected the shape of GP profile. GP rate was improved with the increase of ammonia carbonate in the buffer. GP rate of 0.0 ACC was significantly slow from those of other ACC. Though GP rate of 1.0 ACC was the fastest, but no significant differences were found among ACC levels of1.0, 1.5 and 2.0 in GP rate. The finding from this study proved p H6.9,1.0g ACC and 400mg substrate in buffered rumen fluid, the condition of media was currently used in ID-Lelystad, were appropriate in GP technique for the STAD evaluation of starchy sample. These experiments emphasize the need for standardization of GP technique to facilitate the comparison of results among the samples and laboratories. This need will be extreme when GP is used for feed evaluation. The sensitivenessin GP rate and extent among starchy samples imply the great potential and accuracy of GP technique in evaluating the characteristics of different starchy feedstuffs

Rumen escape protein in grass and grass silage deterimened with a nylon bag and an enzymatic technique

Rumen escape protein (REP) was determined for six grasses and 16 grass silages using a nylon bag technique and an in vitro technique using a proteolytic enzyme preparation of Streptomyces griseus. In vitro, the samples were incubated for 0, 1, 6 and 24 h. The highest correlation observed between percentage REP (%REP), determined with the nylon bag technique, and the in vitro undegradable fraction (U) occurred at 24 h of incubation (%U24; R2=0.71). Shorter incubation periods weakened the relationship (R2=0.46¿0.59). Percentage REP could be estimated from %U24 as %REP=3.3 (±4.02) + 1.31 (±0.19) *%U24. For the incubation periods investigated, results show that the highest relationship with %REP occurred with an incubation period of 24 h for these grass and grass silage samples

Rumen escape protein in grass and grass silage deterimened with a nylon bag and an enzymatic technique

Rumen escape protein (REP) was determined for six grasses and 16 grass silages using a nylon bag technique and an in vitro technique using a proteolytic enzyme preparation of Streptomyces griseus. In vitro, the samples were incubated for 0, 1, 6 and 24 h. The highest correlation observed between percentage REP (%REP), determined with the nylon bag technique, and the in vitro undegradable fraction (U) occurred at 24 h of incubation (%U24; R2=0.71). Shorter incubation periods weakened the relationship (R2=0.46¿0.59). Percentage REP could be estimated from %U24 as %REP=3.3 (±4.02) + 1.31 (±0.19) *%U24. For the incubation periods investigated, results show that the highest relationship with %REP occurred with an incubation period of 24 h for these grass and grass silage samples

Site and extent of starch degradation in the dairy cow : a comparison between in vivo, in situ, and in vitro measurements

Prediction of the supply of glycogenic precursors to dairy cows and the site of degradation of wheat, maize and potato starch (PS) were determined in an in vivo experiment and the results were compared with data obtained from experiments involving in situ nylon bag and in vitro gas production techniques. In a Latin square design experiment four lactating dairy cows fitted with a rumen cannula and T-piece cannulae in the duodenum and terminal ileum, received either a low-starch control diet or diets in which sugar beet pulp in the concentrate mixture had been replaced by wheat, maize or PS. Starch from the different sources was almost completely degraded in the total gastrointestinal tract. For all starches, the rumen was the main site of degradation in vivo. No digestion of PS in the small intestine was observed. In situ results suggested that 14% of wheat starch (WS), 47% of maize starch and 34% of PS escaped rumen fermentation. According to the gas production technique WS ferments quickest and potato slowest. PS had a low degradability during the first 8 (gas production) to 11 (in situ) h. However, according to both in vitro and in vivo measurements rumen degradability of PS was high. The results suggest that in situ and in vitro techniques should be performed in animals that have adapted to starch source to provide a more accurate simulation of the in vivo situatio

Site and extent of starch degradation in the dairy cow - a comparison between in vivo, in situ and in vitro measurements.

Prediction of the supply of glycogenic precursors to dairy cows and the site of degradation of wheat, maize and potato starch (PS) were determined in an in vivo experiment and the results were compared with data obtained from experiments involving in situ nylon bag and in vitro gas production techniques. In a Latin square design experiment four lactating dairy cows fitted with a rumen cannula and T-piece cannulae in the duodenum and terminal ileum, received either a low-starch control diet or diets in which sugar beet pulp in the concentrate mixture had been replaced by wheat, maize or PS. Starch from the different sources was almost completely degraded in the total gastrointestinal tract. For all starches, the rumen was the main site of degradation in vivo. No digestion of PS in the small intestine was observed. In situ results suggested that 14% of wheat starch (WS), 47% of maize starch and 34% of PS escaped rumen fermentation. According to the gas production technique WS ferments quickest and potato slowest. PS had a low degradability during the first 8 (gas production) to 11 (in situ) h. However, according to both in vitro and in vivo measurements rumen degradability of PS was high. The results suggest that in situ and in vitro techniques should be performed in animals that have adapted to starch source to provide a more accurate simulation of the in vivo situatio

Site and extent of starch degradation in the dairy cow : a comparison between in vivo, in situ, and in vitro measurements

Prediction of the supply of glycogenic precursors to dairy cows and the site of degradation of wheat, maize and potato starch (PS) were determined in an in vivo experiment and the results were compared with data obtained from experiments involving in situ nylon bag and in vitro gas production techniques. In a Latin square design experiment four lactating dairy cows fitted with a rumen cannula and T-piece cannulae in the duodenum and terminal ileum, received either a low-starch control diet or diets in which sugar beet pulp in the concentrate mixture had been replaced by wheat, maize or PS. Starch from the different sources was almost completely degraded in the total gastrointestinal tract. For all starches, the rumen was the main site of degradation in vivo. No digestion of PS in the small intestine was observed. In situ results suggested that 14% of wheat starch (WS), 47% of maize starch and 34% of PS escaped rumen fermentation. According to the gas production technique WS ferments quickest and potato slowest. PS had a low degradability during the first 8 (gas production) to 11 (in situ) h. However, according to both in vitro and in vivo measurements rumen degradability of PS was high. The results suggest that in situ and in vitro techniques should be performed in animals that have adapted to starch source to provide a more accurate simulation of the in vivo situatio