The present study was conducted to select a plant oil without inhibitory effects on rumen fermentation and microbes, and to determine the optimal supplementation level of the selected oil in a series of in vitro studies for dietary application. Then, the selected oil was evaluated in a feeding study using Thai crossbred beef cattle by monitoring growth, carcass, blood and rumen characteristics. Rumen fluid was incubated with substrates containing one of three different types of plant oil (coconut oil, palm oil and soybean oil) widely available in Thailand. The effects of each oil on rumen fermentation and microbes were monitored and the oil without a negative influence on rumen parameters was selected. Then, the dose-response of rumen parameters to various levels of the selected palm oil was monitored to determine a suitable supplementation level. Finally, an 8-month feeding experiment with the diet supplemented with palm oil was carried out using 12 Thai crossbred beef cattle to monitor growth, carcass, rumen and blood profiles. Batch culture studies revealed that coconut and soybean oils inhibited the most potent rumen cellulolytic bacterium Fibrobacter succinogenes, while palm oil had no such negative effect on this and on rumen fermentation products at 5% or higher supplementation level. Cattle fed the diet supplemented with 2.5% palm oil showed improved feed conversion ratio (FCR) without any adverse effects on rumen fermentation. Palm oil-supplemented diet increased blood cholesterol levels, suggesting a higher energy status of the experimental cattle. Palm oil had no negative effects on rumen fermentation and microbes when supplemented at levels up to 5% in vitro. Thai crossbred cattle fed the palm oil-supplemented diet showed improved FCR without apparent changes of rumen and carcass characteristics, but with elevated blood cholesterol levels. Therefore, palm oil can be used as a beneficial energy source.

The effect of feeding cashew nut shell liquid (CNSL) on fecal fermentation products and microbiota was investigated in Thai native cattle and swamp buffaloes. Four of each animal were fed rice straw and concentrate diet with control pellets without CNSL for 4 weeks, followed by the same diet with pellets containing CNSL for another 4 weeks, so that CNSL was administered at a level of 4 g/100 kg body weight. Feces were collected the last 2 days in each feeding period. CNSL alkyl phenols were recovered from feces (16%–28%) in a similar proportion to those in the diet, indicating that most functional anacardic acid was not selectively removed throughout the digestive tract. In vitro production of gas from feces, particularly methane, decreased with CNSL feeding. The proportion of acetate in feces decreased with CNSL feeding, whereas that of propionate increased, without affecting total short‐chain fatty acid concentration. CNSL feeding changed fecal microbial community, particularly in swamp buffaloes, which exhibited decreases in the frequencies of Treponema , unclassified Ruminococcaceae , and Methanomassiliicoccaceae . These results suggest that CNSL feeding alters not only rumen fermentation but also hindgut fermentation via modulation of the microbial community, thereby potentially attenuating methane emission from the feces of ruminant animals.

In addition to blood pathogen transmission, insects of the order Diptera affect livestock through visual and contact harassment; blood-feeders are responsible for painful bites and blood despoliation, generating behavioral modifications, anemia, and production losses. Knowledge of their economic impact is a basis for cost-effective control. Here, we measured the global impact of diptera insects by comparing two batches of six feeder cattle, one in the open air and the other protected by a mosquito net. The analytical data were insect density in the open air and, for feeder cattle, tail flick counts, hematocrit values (Ht), feed intake, feed conversion ratio (FCR), and live body weight gain (LBWG). Over a period of five months, the results showed significant losses in the LBWG of cattle exposed to insects, estimated at 8.0 ± 1.5 kg/month [2.7; 13.3], with a total loss reaching 40.0 ± 5.5 kg/head. Main diurnal insects were Stomoxys spp. and Musca crassirostris. There was a strong correlation between fly density and diurnal tail flicks. Night trapping and tail flicks showed a potentially important role of mosquitoes to be further explored. The Ht levels of exposed animals were 3–4% lower than those of controls. FCRs indicated that exposed animals needed 33% more dry matter intake/kg of LBWG. An economic assessment showed that dipterans were responsible for a 10–11% loss in LBWG during the main growing period of feeder cattle (10–15 months). A feedlot of 100 calves would register a total loss of USD 16,000 within 5 months, which appears to be an unexpectedly huge loss caused by dipterans. Investing part of this money into fly control would probably be beneficial.

The objectives of the experiment were to determine plant spacing and variety to produce the suitable growth, yield components, biomass yield of field corn and nutritional value of corn silage in paddy field condition. The field experiment was conducted at the Lopburi Research Station, Khok Charoen district, Lopburi province, Thailand in 2018-2019 and was arranged in a split plot design in randomized complete block design (RCBD) with 4 replications. The main plot contained 3 plant spacings viz. 75×15, 75×20 and 75×25 cm and sub plot consisted of 5 field corn varieties (CP888, NS3, S7328, SW4452 and SW5). The results showed that wide spacing tended to produce higher ears per plant than narrow spacing. CP888 was the highest ears per plant variety. NS3 was the highest leaf/stem ratio variety. SW5 showed high leaf, stem and fresh biomass yield and it also produce ear yield closing to a high ear yield variety at 75×25 cm spacing. Moreover, SW5 also had high crude protein (CP) content, while plant spacing did not significantly affect acid detergent fiber (ADF), acid detergent lignin (ADL), ash, and lactic acid of corn silage. The widest spacing (75×25 cm) showed lower NDF than the narrowest spacing (75×15 cm). It was evident that SW5 and 75×25 cm spacing may be considered optimum for biomass yields without negatively affecting the corn silage quality.   Keywords: Nutritional value, Paddy field, Plant spacing, Silage corn, Variety Funding: This work was supported by the research grant of Kasetsart University in 2018.   Citation: Chotchutima, S., Boonsaen, P., Jenweerawat, S., Pleangkai, S., Romkaew, J., Jompuk, C., Sarobol, E., and Tudsri, S. 2022. Influence of varieties and spacings on growth, biomass yield and nutritional value of corn silage in paddy field. CMU J. Nat. Sci. 21(1): e2022017.

The effect was determined of cellulolytic Ruminococcus albus KU-F152 and non-cellulolytic Selenomonas ruminantium S137 on the digestibility, feedlot performance, carcass characteristics and meat quality of Holstein crossbred steers. Eight steers were randomly inoculated with R. albus KU-F152 and S. ruminantium S137, and eight steers were used as the non-inoculated control. The steers were fed a Total mixed ration (TMR) diet (21:79 ratio of corn silage and concentrate) that was offered ad libitum for 6 months. The results showed that the inoculation of R. albus KU-F152 and S. ruminantium S137 had no positive effect on the growth performance of Holstein steers; however, the inoculation increased the feed conversion ratio (FCR) compared with the control. The ruminal fermentation results demonstrated that R. albus and S. ruminantium inoculation significantly increased total volatile fatty acid (VFA), levels and increased the marbling score of meat as carcass characteristics. Regarding meat quality characteristics, R. albus and S. ruminantium inoculation increased the meat fat and reduced the thawing loss. Furthermore, the meat of the treatment group had a significantly lower shear force (tender meat) and a lighter colour than that of the non-inoculated control.