Pichad Khejornsart

Effects of plants containing secondary compounds and plant oils on rumen fermentation and ecology

A number of experiments have been conducted to investigate effects of tropical plants containing condensed tannins and/or saponins present in tropical plants and some plant oils on rumen fermentation and ecology in ruminants. Based on both in vitro and in vivo trials, the results revealed important effects on rumen microorganisms and fermentation including methane production. Incorporation and/or supplementation of these plants containing secondary metabolites have potential for improving rumen ecology and subsequently productivity in ruminants.

Effects of Plant Herb Combination Supplementation on Rumen Fermentation and Nutrient Digestibility in Beef Cattle

Four rumen-fistulated crossbred beef cattle (Brahman native) were randomly assigned according to a 4×4 Latin square design experiment to be fed plant herb supplements in their concentrate mixture. The treatments were: without herb supplementation (Control), lemongrass meal supplementation at 100 g/d (L), lemongrass meal supplementation at 100 g/d plus peppermint powder at 10 g/d (LP), and lemongrass meal supplementation at 100 g/d plus peppermint powder at 10 g/d with garlic powder 40 g/d (LPG), respectively. Based on the present study, the DMI and apparent digestibility of DM, OM, aNDF and ADF were not affected by dietary herb supplementation while CP digestibility tended to be decreased by herb supplement. Moreover, NH3-N and BUN were decreased in all herb supplemented treatments and there was a tendency to an increase in ruminal pH in all herb supplemented groups. While there was no change in TVFA and C4 among lemongrass treatments, C2 was decreased in all herb supplemented treatments while C3 was increased. Methane production by calculation was the lowest in the LP and LPG groups. Population sizes of bacteria and protozoa were decreased in all herb supplemented groups, but not fungal zoospores. In all supplemented groups, total viable and proteolytic bacteria were decreased, while amylolytic and cellulolytic bacteria were similar. More importantly, in all herb supplemented groups, there were higher N balances, while there was no difference among treatments on purine derivative (PD) excretion or microbial N. Based on the results above, it could be concluded that there was no negative effect on ruminal fermentation characteristics and nutrient utilization by plant herb supplement, but protozoal population and CH4 production were reduced. Thus, lemongrass alone or in combination with peppermint and garlic powder could be used as feed additives to improve rumen fermentation efficiency.

Effect of eucalyptus (Camaldulensis ) leaf meal powder on rumen fermentation characteristics in cattle fed on rice straw

Three, Holstein Friesian, non-lactation crossbred dairy cows were used to evaluate the effect of Eucalyptus (Camaldulensis) leaf meal powder (EUCAP) supplementation on feed intake, digestibility and rumen fermentation. The animals were randomly assigned according to a 3 × 3 Latin square design using three levels of EUCAP supplementation (0, 100 and 200 g/hd/d) and offered rice straw ad libitum, together with concentrate at 0.5% body weight. The results revealed that voluntary feed intake kg/hd/d) was significantly decreased when EUCAP was supplemented at 200 g/hd/d. Digestibility coefficient (%) of DM, OM, CP, NDF and ADF were similar among treatments. Ruminal temperature and pH were not affected by EUCAP supplementation. However, NH3-N and BUN concentrations were decreased when supplementation of EUCAP at 200 g/hd/d. Ruminal fungal zoospores were not significantly different among treatments, while protozoa, bacteria population by direct counts were significantly reduced with increasing supplementation levels of EUCAP. In addition, viable total bacteria, proteolytic bacteria and cellulolytic bacteria were decreased when EUCAP were supplemented at 100 and 200 g/hd/d while amylolytic bacteria was not different among treatments (P>0.05). Furthermore, total volatile fatty acid concentrations, proportion of acetate, acetate to propionate ratio were reduced with increasing level of supplementation, while, proportion of propionate increased. Methane production was reduced in supplemented treatments at 100 g/hd/d. Supplementation of EUCAP at 100 g/day for ruminants could be on alternative feed enhancer which reduces rumen methane gas production in cattle, while nutrient digestibilities were unchanged. Key words: Eucalyptus, rumen fermentation, rice straw, rumen manipulation, cows.

Nutrient digestibility and ruminal fermentation characteristic in swamp buffaloes fed on chemically treated rice straw and urea

The experiment was conducted to determine effects of urea–lime-treated rice straw and urea levels in concentrate on rumen fermentation, apparent nutrient digestibility, and cellulolytic bacteria population of 4-year-old, rumen-fistulated swamp buffaloes. All animals were randomly assigned according to a 2 × 2 factorial arrangement in a 4 × 4 Latin square design to receive four dietary treatments: factor A, two sources of roughage (rice straw and 2%urea + 2%lime-treated rice straw); factor B, two levels of urea in concentrate mixture (0% and 4%). Roughages were given ad libitum together with 0.3% BW of concentrate. It was found that voluntary feed intake, the digestibility of DM, OM, CP, NDF, acetate, and propionate concentration were significantly increased (P < 0.05) by treated rice straw, while NH3-N, BUN, and propionic acid concentration were increased by both factors of treated rice straw and 4% urea in concentrate. The real-time PCR quantification of Fibrobacter succinogenes and Ruminococcus albus population, and anaerobic fungi were greater (P < 0.05), but the population of Ruminococcus flavefaciens, protozoa, and methanogenic bacteria were reduced (P > 0.05) as influenced by treated rice straw and urea level. In conclusion, the combined use of urea–lime-treated rice straw and fed with concentrate (4% urea) could improve rumen ecology, rumen fermentation efficiency, and nutrient digestibility in swamp buffaloes.

Effect of Carbohydrate Source and Cottonseed Meal Level in the Concentrate on Feed Intake, Nutrient Digestibility, Rumen Fermentation and Microbial Protein Synthesis in Swamp Buffaloes

The objective of this study was to investigate the effect of carbohydrate source and cottonseed meal level in the concentrate on feed intake, nutrient digestibility, rumen fermentation and microbial protein synthesis in swamp buffaloes. Four, 4-yr old rumen fistulated swamp buffaloes were randomly assigned to receive four dietary treatments according to a 2×2 factorial arrangement in a 4×4 Latin square design. Factor A was carbohydrate source; cassava chip (CC) and CC+rice bran at a ratio 3:1 (CR3:1), and factor B was level of cottonseed meal (CM); 109 g CP/kg (LCM) and 328 g CP/kg (HCM) in isonitrogenous diets (490 g CP/kg). Buffaloes received urea-treated rice straw ad libitum and supplemented with 5 g concentrate/kg BW. It was found that carbohydrate source did not affect feed intake, nutrient intake, digested nutrients, nutrient digestibility, ammonia nitrogen concentration, fungi and bacterial populations, or microbial protein synthesis (p>0.05). Ruminal pH at 6 h after feeding and the population of protozoa at 4 h after feeding were higher when buffalo were fed with CC than in the CR3:1 treatment (p<0.05). Buffalo fed with HCM had a lower roughage intake, nutrient intake, population of total viable and cellulolytic bacteria and microbial nitrogen supply than the LCM fed group (p<0.05). However, nutrient digestibility, ruminal pH, ammonia concentration, population of protozoa and fungi, and efficiency of microbial protein synthesis were not affected by cottonseed meal levels (p>0.05). Based on this experiment, concentrate with a low level of cottonseed meal could be fed with cassava chips as an energy source in swamp buffalo receiving rice straw.