Hiro-omi Yokota

Bark stripping preference of sika deer, Cervus nippon, in terms of bark chemical contents

Abstract Recent increases in the population of sika deer, Cervus nippon, on Mt. Ohdaigahara in central Japan, have resulted in severe damage to trees through bark stripping. We evaluated which tree species are selectively barked using Ivlev’s selection index and the bark chemical contents of each tree species. We measured the area of stripped bark for 25 tree species from July to September 1999 and analyzed the crude protein, fiber and mineral contents of the trunk bark of eight tree species. Sika deer preferred the bark of Clethra barbinervis and Ilex geniculata but not Fagus crenata and Acer shirasawanum. The bark chemical contents showed no significant relationships with Ivlev’s selection index except for Ca, which had a negative relationship. The bark contents analyzed in this study do not explain the tree bark preferences of sika deer.

Monitoring of forage conditions with MODIS imagery in the Xilingol steppe, Inner Mongolia

A study was conducted to determine the potential suitability of Terra/MODIS imagery for monitoring short‐term phenological changes in forage conditions in a semi‐arid region. The study sites included four meadow steppes and six typical steppes in the Xilingol steppe in central Inner Mongolia, China. The live biomass, dead standing biomass, total biomass, crude protein (CP) concentration and standing CP were estimated from early April to late October using the Enhanced Vegetation Index (EVI) values from Terra imagery (500 m pixels). Applying regression models, the EVI accounted for 80% of the variation in live biomass, 42% of the dead biomass, 77% of the total biomass, 11% of the CP concentration and 74% of the standing CP. MODIS/EVI is superior to AVHRR/NDVI when estimating forage quantity. Applying these results, the seasonal changes in live biomass and the standing CP could be described in the selected four sites with different degrees of grazing intensity. Generally, the increase in grazing intensity tended to decrease live biomass and standing CP. It was suggested that the EVI obtained from Terra imagery was an available predictor of the forage condition as measured by live biomass and standing CP. The MODIS/EVI values could provide information on the suitable timing of cutting for hay‐making and nutritive value to range managers.

The gut microflora and the uptake of glucose from the small intestine of the chick

1. Chicks whose growth rate had been depressed either by a fully conventional flora or by association with a bile acid deconjugating strain of Streptococcus faecium and/or a filterable agent from chicken droppings showed no significant reduction in uptake of 3-0-methyl-alpha-D-glucopyranose compared with germ-free birds. 2. Association with a microflora increased the weight of the gut per unit length.

A method of making good quality silage from direct cut alfalfa by spraying previously fermented juice

Abstract Three laboratory-scale experiments were carried out using direct cut alfalfa and 900-ml glass bottle silos. In Experiment 1, effects of different temperatures (20, 30 and 40°C) and additives (previously fermented juice, PFJ, and Lactobacillus casei , LAB) on silage quality were studied. Experiment 2 involved the same treatments as Experiment 1 with the exception that material was only preserved at 30°C. In Experiment 3, effect of addition of PFJ made from diluted alfalfa juice on silage quality was studied. In each experiment, part of the alfalfa was ensiled without any additive (None). All the treatments consisted of three replicate silos and they were preserved for 45 days. The PFJ was prepared by macerating 200 g of freshly harvested alfalfa with 600 ml of water, filtering through double cheese cloth, adding 40 g l −1 glucose and incubating anaerobically at 30°C for 2 days. In Experiment 3, 2- and 20-fold dilutions of alfalfa juice with 20 g l −1 glucose solution before fermentation were made. They were added at 2.5 ml kg −1 of chopped alfalfa. One ml of a solution containing 10 8 L. casei inoculated 1 kg of chopped alfalfa. Silage quality was affected by both temperature and additive treatments. Without an additive, well-fermented silage was obtained only at 40°C. Inoculation with L. casei , a conventional additive, of alfalfa at ensiling was sometimes effective but sometimes not, while addition of PFJ, a novel additive, at 2.5 ml kg −1 fresh alfalfa improved silage quality independently of harvest seasons, growing stages and storage temperatures. Twenty-fold dilution of alfalfa juice with glucose solution before fermentation was possible without decreasing its potential as the silage additive.

Protein and energy utilization in germ-free and conventional chicks given diets containing different levels of dietary protein

The present study was done to clarify the relationship between the amount of dietary protein given to, and the gut microflora of, the host. Day-old chicks were given diets containing three concentrations of dietary protein (50, 200 and 400 g/kg) for 14 d. Body-weight gain, food consumption, body consumption, and protein and energy utilization were measured. There was no difference in body-weight gain and food consumption between germ-free (GF) and conventional (CV) chicks, but food conversion efficiency (g body-weight gained/g food consumed) was significantly higher in GF than in CV chicks. Little difference was found in protein retention (g protein retained/14 d), but protein retention rate (g protein retained/g protein consumed) tended to be higher in GF chicks, particularly those given the diet with the lowest protein. The presence of micro-organisms improved metabolizable energy (ME) values of the diets, but not all of the digested energy in CV chicks was utilized for growth. Therefore there was little difference in energy retention (kJ energy retained/14 d) between environments, although energy retention rate (kJ energy retained/kJ ME consumed) was significantly lower in CV chicks. The amount of body fat in GF chicks was higher than that in CV chicks, especially in those fed on the low-protein diet. It is suggested that although the gut microflora may have beneficial effects on the digestion of dietary energy components, they may have detrimental effects on utilization of ME by their hosts, because chicks harbouring a gut microflora seem to have higher energy requirements for maintenance.

Effect of the gut microflora on chick growth and utilisation of protein and energy at different concentrations of dietary protein.

The effect of the gut flora on chick growth and protein and energy utilisation at a marginal dietary energy level (calculated metabolisable energy value 11.7 MJ/kg) was determined with diets containing 227 or 293 g protein/kg. Germ-free (GF) and conventional (CV) chicks were reared for 10 d on the diets, and excreta were collected during the last 4 d. The chicks were killed and carcases and droppings were analysed for N and fat. The GF chicks grew significantly faster than the CV controls on both diets. The growth of CV chicks given the high protein diet was similar to that of GF chicks given the adequate protein diet. Protein and energy utilisation were significantly less for CV than for GF chicks on both diets. It was concluded that the energy requirement of CV chicks was greater than that of their GF counterparts, and that their poorer growth was due to utilisation of some dietary protein as an energy source.

Effect of the gut Microflora on the size and weight of organs of chicks fed diets of different protein content

Germ-free (GF) and conventional (CV) chicks were reared for 14 d on diets containing 50 (LD), 200 (AD) and 400 (HD) g protein/kg. Food and water were provided ad libitum. The size and weight of the proventriculus, gizzard, duodenum, jejunum, ileum, caeca, colon, liver, pancreas, heart, spleen, adrenal glands and kidneys were measured, and liver composition was examined. The absolute and relative (weight/kg body-weight) weights of the intestine of CV chicks fed AD and HD diets were greater than those of GF chicks. The LD diet did not affect the absolute and relative weights of the duodenum and jejunum. The absolute weight, relative weight and fat content of the liver of GF chicks given LD diet were greater than those of their CV counterparts. The size and weight of some organs are affected by the diet (dietary protein content)-microflora-host interaction.

Influence of Energy Intake on Growth and Utilisation of Dietary Protein and Energy in Germ-Free and Conventional Chicks

The effect of metabolisable energy (ME) intake on the growth and utilisation of dietary protein and energy in germ-free (GF) and conventional (CV) chicks was investigated in two experiments. In experiment 1 a high energy diet (HED, 14.8 kJ ME/g) and a marginally-adequate energy diet (AED, 11.7 kJ ME/g) were fed to the GF and CV chicks at 240 g/2 birds/10 d. In experiment 2 a diet with 13.7 kJ ME/g was fed at 118 g (low level, LL) or 128 g (high level, HL)/bird/10 d. Body weight gain, protein retention and protein retention rate were similar in GF and CV chicks on both AED and HED in the first experiment, but in the second were higher in GF than in CV chicks. The increased ME intake of the CV chicks in experiment 2 may be too small to compensate for the increased requirement. ME intake was significantly higher in the CV chicks than in the GF chicks, whereas energy retention was similar in both groups.

Effect of graded levels of ethoxyquin in alfalfa leaf extracts on carotenoid and cholesterol concentrations in chicks

Abstract Alfalfa leaf extract treated with graded levels of ethoxyquin was incorporated into a casein diet at a level of about 50 g kg−1. The six leaf extracts contained 0, 956, 2435, 6777, 11 316, 25 150 mg kg−1 ethoxyquin and gave final concentrations of 0, 50, 125, 350, 600, and 1400 mg kg−1 in the diet, respectively. Each diet was supplemented with methionine, arginine and glycine and contained 120 g crude protein kg−1 and a similar level of energy. Seven-day old chicks were allocated to six treatments (n = 8) and fed the above experimental diets for 2 weeks. Dietary ethoxyquin up to 125 mg kg−1 improved body weight gain from 88 to 98 g and gain per feed from 0.44 to 0.46 although the differences were not significant. However, levels of ethoxyquin in the diet higher than 350 mg kg−1 significantly reduced both the body weight gain and gain per feed; these were 79 g and 0.41, respectively, in chicks fed the diet containing 1400 mg ethoxyquin kg−1. Plasma cholesterol level was significantly reduced from 209 with the control diet (containing 0 mg kg−1 ethoxyquin) to 157 mg dl−1 with the diet containing 50 mg kg−1 ethoxyquin. It was also lower with 125 mg kg−1 ethoxyquin than with the control diet, but higher levels of dietary ethoxyquin increased plasma cholesterol compared with that obtained with the control diet. Carotenoid concentration in the skin, liver and blood plasma were linearly reduced with the increase of ethoxyquin intake from 30.2, 75.0 and 38.4 μg g−1 at 0 mg intake to 19.2, 30.3 and 23.7 μg g−1 at 1400 mg ethoxyquin kg−1 diet, respectively.

Assessment of Anti-nutritive Activity of Tannins in Tea By-products Based on In vitro Rumen Fermentation

Nutritive values of green and black tea by-products and anti-nutritive activity of their tannins were evaluated in an in vitro rumen fermentation using various molecular weights of polyethylene glycols (PEG), polyvinyl pyrrolidone (PVP) and polyvinyl polypyrrolidone as tannin-binding agents. Significant improvement in gas production by addition of PEG4000, 6000 and 20000 and PVP was observed only from black tea by-product, but not from green tea by-product. All tannin binding agents increased NH3-N concentration from both green and black tea by-products in the fermentation medium, and the PEG6000 and 20000 showed relatively higher improvement in the NH3-N concentration. The PEG6000 and 20000 also improved in vitro organic matter digestibility and metabolizable energy contents of both tea by-products. It was concluded that high molecular PEG would be suitable to assess the suppressive activity of tannins in tea by-products by in vitro fermentation. Higher responses to gas production and NH3-N concentration from black tea by-product than green tea by-product due to PEG indicate that tannins in black tea by-product could suppress rumen fermentation more strongly than that in green tea by-product.