C. Wachirapakorn

Manipulation of ruminal fermentation and methane production by dietary saponins and tannins from mangosteen peel and soapberry fruit

Four fistulated Holstein Friesian heifers were used in a 4 × 4 Latin square design with a 2 × 2 factorial arrangement. The main factors were two roughage-to-concentrate ratios (R:C, 70:30 and 30:70) and two supplementation levels of soapberry fruit-mangosteen peel (SM) pellets (0 and 4% tannins-saponins of total diets). Rice straw was used as a roughage source. The diet was fed ad libitum as a total mixed ration. SM pellets contained crude tannins and saponins at 12.1 and 15.7% of DM, respectively. It was found that at R:C 30:70 the DM intake and the digestibility of DM, CP and NDF were increased (p < 0.05), while SM pellet supplementation reduced the DM digestibility (p < 0.05). Ruminal pH was decreased at R:C 30:70. Total VFA and propionate was increased at high concentrate level and after SM pellet supplementation (p < 0.05); simultaneously, the acetate concentration and the acetate-to-propionate ratios were decreased (p < 0.05). Methane production was decreased at R:C 30:70 and additionally when SM pellets were supplemented (p < 0.05). This was in agreement with the percentage of methanogens in total ruminal DNA. Furthermore, the number of fungal zoospores were reduced at a higher concentrate proportion (R:C 30:70) and by SM-pellet supplementation (p < 0.05). Protozoal populations were diminished when SM pellets were supplemented (p < 0.05). In this study, it was shown that the roughage-to-concentrate ratio, as well as the supplementation of SM pellets containing condensed tannins and saponins, caused changes in ruminal microorganisms and their fermentation end-products.

Influence of urea–calcium mixtures as rumen slow-release feed on in vitro fermentation using a gas production technique

In this experiment the effects of different urea products (urea [U] and urea–calcium mixtures [UCM]) on rumen fermentation were investigated in dependence of different energy sources by using in vitro techniques. The 7 × 2 factorial arrangement followed a completely randomised design using seven urea products (U100, U40CaCl2, U50CaCl2, U60CaCl2, U40CaSO4, U50CaSO4 and U60CaSO4) in combination with cassava chips (CC) or corn meal (CM). Compared with other treatments, the cumulative gas production (96 h) was significantly increased for U60CaCl2 + CC and U60CaSO4 + CC (p < 0.01), which was combined with a higher in vitro true digestibility (p < 0.01). In addition, the concentration of volatile fatty acids in the fluid of U60CaCl2 + CC and U60CaSO4 + CC was significantly higher than in other treatments. Urea treatments (U100 + CC and U100 + CM) caused the highest concentration of ruminal ammonia nitrogen (p < 0.01), which was significantly decreased by all UCM products in combination with CC, but not with CM. The highest levels of total bacteria, Fibrobacter succinogenes and anaerobic fungi were found for treatment U60CaCl2 + CC and U60CaSO4 + CC (p < 0.05). The findings revealed that the utilisation of U60CaCl2 and U60CaSO4 in combination with cassava chips improved the ruminal fluid fermentation in terms of NH3-N and volatile fatty acid concentration, digestibility of energy and increased the fibrobacter concentrations.

The effects of high levels of rumen degradable protein on rumen pH and histamine concentrations in dairy cows

An experiment was conducted to test the hypothesis that the supplementation of crude protein (CP) results in rumen acidosis and increased histamine concentrations in dairy cows. Six ruminally fistulated, non-pregnant dry cows were fed three experimental rations in a replicated 3 × 3 Latin square design. The CP contents in the low-CP, the high rumen undegradable protein (high-RUP) and the high rumen degradable protein (high-RDP) rations were 112, 259 and 266 g/kg dry matter (DM) respectively. The cows were fed 7.7 kg DM of the concentrates and 2.7 kg DM of rice straw. High levels of RDP in the ration significantly increased the ammonia, total volatile fatty acid (VFA) and histamine concentrations in the rumen fluid. However, supplemental CP, whether degradable or undegradable, did not significantly affect the pH of rumen fluid. Plasma urea nitrogen concentration was higher in both high-RDP and high-RUP in relation to cows fed the low-CP ration. The rise in ruminal histamine concentrations was physiologically non-relevant, most likely because rumen pH was not affected by supplemental CP at the installed level of DM intake. Therefore, it can be concluded that the issue of supplemental CP, rumen pH and ruminal histamine concentrations has not yet been settled. Further research is warranted to understand these relationships.

Effect of ground corn cobs as a fiber source in total mixed ration on feed intake, milk yield and milk composition in tropical lactating crossbred Holstein cows

The aim of this study was to evaluate the effect of ground corn cobs (GCC) as a sole fiber source in total mixed ration (TMR) on feed intake, milk yield and milk composition in tropical lactating crossbred Holstein cows. Four multiparous crossbreds Holstein Friesian dairy cows with an initial body weight (BW) of 415.5 ± 26.20 kg were used in a 4 × 4 Latin square design. The dietary treatments of TMR contained a roughage-to-concentrate ratio of 40:60. The roughage source was used at different ratios of GCC to rice straw (RS) at 100:0, 82.5:17.5, 67.5:32.5, and 50:50 for TMR1 to TMR4, respectively. The results revealed significant improvements in intake of dry matter, protein, neutral detergent fiber (NDF) and metabolizable energy (ME) for TMR1 and TMR2 (P < 0.05), while the digestibility of nutrients was not altered by the treatments (P ≥ 0.05). Ground corn cobs was used for up to 100% of the total roughage without affecting milk production. Moreover, ruminal pH, temperature, ammonia-nitrogen (NH3—N) and volatile fatty acid (VFA) concentrations were not impacted by the treatments (P > 0.05). However, milk yield was significantly different among the GCC:RS ratios (P < 0.05) and was the highest in TMR1 and TMR2 (13.1 kg/d), while the milk compositions were not changed (P > 0.05). The results imply that using GCC as a whole roughage source significantly improved nutrients intake and milk yield in dairy cows raised in tropical areas.

Effect of whole cottonseed v. sunflower seed on the fatty acid profile of subcutaneous fat, longissimus dorsi and blood of Thai Native and Holstein bulls.

In a 2×2 factorial design, 12 Thai Native and 12 Holstein bulls were fed ad libitum a total mixed ration (20 : 80; roughage : concentrate) with whole cottonseed (WCS) or sunflower seed (SFS) as oilseed sources. The rations contained 7% crude fat and were fed for 90 days. Plasma was taken at three times during the experiment, and at slaughter the longissimus dorsi and subcutaneous fat were sampled for fatty acid analysis. Ration did not affect rumen fermentation parameters. The plasma fatty acid profile was not affected by ration. In subcutaneous fat, a ration×breed interaction for the saturated fatty acid (SFA) and c9t11 CLA proportions was observed, resulting from larger differences between the rations in Thai Native compared with Holstein bulls. The WCS ration resulted in higher proportions of SFA and lower proportions of monounsaturated fatty acids and c9,t11 CLA compared with the SFS ration (P<0.01). In the intramuscular fat, the WCS ration was also associated with a lower c9t11 CLA proportion (P<0.01) and higher SFA proportion (P<0.05). The intramuscular proportion of polyunsaturated acids was higher and the proportion of SFA was lower in Thai Native compared with Holstein bulls (P<0.05), irrespective of ration.

Effects of levels of crude protein and ground corn cobs in total mixed ration on intake, rumen fermentation and milk production in crossbred Holstein Friesian lactating dairy cows

Four, multiparous Holstein Friesian dairy crossbred cows with an initial body weight of 421.3 ± 44.3 kg and day-in-milk 62 ± 4.2 days were arranged according to a 4 × 4 Latin square design to evaluate the effect of levels of crude protein (CP) and ground corn cobs (CCs) in total mixed ration (TMR) on feed intake, rumen fermentation and milk production. The crude protein levels in TMR used in this experiment were 12%, 14%, 16% and 18% of dry matter (DM). Ground CCs and rice straw (1:1) were used as roughage sources and mixed with concentrate at 40:60 ratios. It was found that increasing CP in TMR resulted in linearly increasing voluntary DM intake (12.2, 12.7, 12.6 and 14.3 kg/d), protein intake (1.4, 1.8, 2.0 and 2.5 kg/d) and organic matter intake (11.2, 11.7, 11.6 and 13.0 kg/d). Digestion coefficients, ruminal pH and total volatile fatty acids were not different among dietary treatments (P > 0.05). However, ruminal ammonia-nitrogen and blood urea-nitrogen were increased when levels of CP in TMR increased (P < 0.05). Daily milk yield (11.5, 12.1, 12.3 and 13.1 kg/hd/d) and milk protein (3.2%, 3.2%, 3.4% and 3.6%) were increased with incremental additions of CP (P < 0.05), while there was no further improvement in milk fat content and feed efficiency beyond 16% CP (P > 0.05). Results indicate that TMR containing highest CP were excessive in N utilisation. It is, therefore, concluded that TMR contained 14% of CP in the diet meets the protein requirement for lactating cows producing 11–13 kg milk/d.

In vitro rumen fermentation and methane production as affected by rambutan peel powder

ABSTRACT The current study was aimed to determine the effect of rambutan peel powder (RPP) supplementation on in vitro gas production, rumen fermentation characteristics and methane production. The experimental design was a completely randomized design and the dietary treatments were different levels of RPP supplementation at 0, 4, 8, 12, 16 and 20 mg/0.5 g DM. Under this investigation, RPP supplementation did not affect gas production kinetics and in vitro digestibility (p > .05). The concentration of NH3-N decreased linearly with the increasing levels of RPP supplementation (p < .05). Propionate was increased (p < .05) when supplemented with RPP at 16 mg, while acetate and butyrate remained the same. On the other hand, supplementation of RPP decreased methane production (p < .05). This study indicated that RPP at 16 mg could be used as a rumen enhancer for manipulating rumen fermentation.