Effect of Cellulase and Lactic Acid Bacteria on Fermentation Quality and Chemical Composition of Wheat Straw Silage

The object of this study was to determine the effect of cellulase and lactic acid bacteria (LAB) on fermentation quality and chemical composition of wheat straw silage. Silages were prepared using a small-scale fermentation system and the moisture level was adjusted to 60% of fresh matter (FM) with deionized water. Treatments were designed as: control silage without additives, LAB inoculant Lactobacillus casei Z3-1 (1.0 × 106 cfu·g-1 of FM), commercial inoculant L. plantarum FG 1 (1.0 × 106 cfu·g-1 of FM), Z3-1 + cellulase and FG 1 + cellulase. The neutral detergent fiber (NDF), acid detergent fiber (ADF) and crude protein (CP) contents of the wheat straw prior to ensiling were 76.93%, 48.52% and 4.63% of dry matter (DM), respectively. After 30 days of fermentation, the silages treated with LAB and LAB + cellulase had a lower (P < 0.05) pH and higher (P < 0.05) lactic acid content than the control, and the coliform bacteria, yeast and mold were inhibited at the early stage of fermentation. Besides, silages treated with cellulase had lower (P < 0.05) values of ADF and NDF than the control. The results confirmed that the addition of cellulase and LAB contributed to improving the fermentation quality of wheat straw silage.

Mapping of Quantitative Trait Loci Affecting Eggshell Quality in an F_2 Population Derived from Strong and Weak Eggshell Lines of the White Leghorn Chicken Breed

Broken and cracked eggshells cause major economic losses to the egg production industry. An F2 population of 262 hens obtained by crossing a strong egg shell line with a weak egg shell line of the White Leghorn breed was used for detecting the quantitative trait loci （QTL） affecting eggshell quality. The 2 lines were developed from the same founder population by two-way selection for egg shell strength with nondestructive deformation. Of the 1 014 microsatellite markers tested, 35 were mapped on 10 autosomal linkage groups. There was no informative marker on chromosome Z. The QTLs associated with 7 traits, i.e., body weight, short length of egg, long length of egg, eggshell strength, eggshell thickness （EST）, eggshell weight （ESW）, and egg weight （EW）, were identified. Highly significant （P〈0.01） QTLs associated with EST and ESW and a significant （P〈 0.05） QTL associated with EW were mapped to a region flanking ABR0545 and ABR0362 on chromosome 9. These QTLs are good candidates to be employed in the development of strategies for reducing the number of broken and cracked eggs in commercial layer houses by employing marker assisted selection.

Evaluation of genetic diversity and conservation priorities for Egyptian chickens

In this study, 21 microsatellite markers were used to genotype 196 Egyptian local chickens obtained from Fayoumi (n = 35), Dandarawy (n = 30), Baladi (n = 29), Sinai (n = 30), El-Salam (n = 36), and Golden Montazah (n = 36) strains. The results were compared to two pure commercial chicken populations reared in Japan-White Leghorn (n = 42) and Rhode Island Red (n = 43). A total of 162 alleles were observed, with an average of 7.7 alleles per locus. The average expected heterozygosity for the Egyptian chickens was 0.595. The closest pairwise Nei’s genetic distance was recorded between Sinai and Golden Montazah (0.038) and the smallest pairwise FST value (0.006) was observed between Baladi and Sinai. The most probable structure clustering of the eight studied populations was at K = 6. Baladi, Sinai and Golden Montazah strains were clustered together forming admixed mosaic cluster. Dandarawy ranked firstly and contributed the most to aggregate genetic diversity based on two prioritization methods. The information resulting from this study may be used as an initial guide to design further investigations for development of sustainable genetic improvement and conservation programs for the Egyptian chicken genetic resources.

Development of Techniques for Animal Feed from Corn and Their By-Products

Research results concerned （ 1 ） quantification of pH value and contents of ammonia nitrogen, volatile fatty acids （VFAs）, and lactic acid, which were indicators of fermentative quality of corn stover silage and other crop by-product silages ; （2） introduction of methods for analyses of fiber content in feeds such as detergent and enzymatic analyses; （3） determination of digestive characteristics in the tureen by artificial digestion trials （ in vitro and in situ ） ; （ 4 ） evaluation of meat productivity and quality by feeding corn stover silage to beef cattle in feeding experiments and; （5） preparation of feed composition and feeding standards for animals in Jilin Province. These results and methods substantially contributed to stabilization of feed supply as well as an increase in the efficiency of meat production, resulting in sustainable development of livestock management in China.

Chemical Composition and Ruminal Digestibility of Ceratoides, a Salt-tolerant Perennial Plant,at Different Years

It has been proposed that salt-tolerant plant could be used as a feed resource for ruminants whereby salt would be removed from salinized land (Asian -Aust. J. Anim. Sci. (2002) 15:998 -1001). Ceratoides arborescens (Losinsk.) Tsien et C. G. Ma is known as a drought-and salt-tolerant plant,a kind of shrubs, growing in semi-arid land of Inner Mongolia. Because the covering effect of the perennial plant as a mulch over the soil might be expected, the optimum covering effect would be obtained after the growth period.The perennial plant produces seeds around summer and end its growth thereafter. Nutrient value of the perennial salt-tolerant plant, however,had not been reported in flowering period at different year. It is necessary to know the ruminal degradability of the plants of each growing year in order to determine the regimen to diet for ruminants. The present experiment,therefore,was undertaken to analyze the digestibility and chemical composition of Ceratoides arborescens as feed for ruminants.

Analysis of Grassland Vegetation of the Southwest Heilongjiang Steppe （China） Using the Power Law

In 1997, we conducted a vegetation survey in three semi-arid natural grasslands （steppes） with different livestock grazing intensities in Southwest Heilongjiang Province, China, The dominant grassland species was the grass Stipa baicalensis Roshev. Grasslands with light, intermediate, and heavy grazing intensities were located 10, 5, and 2 km from a village, respectively. Villagers use the steppe to raise cattle, horses, sheep, and goats. Each of the three grasslands was surveyed by placing 100 quadrats （50 cm×50 cm） along a 50 m line transect. Each quadrat was divided into four equal areas （25 cm×25 cm; S-quadrats） and all plant species occurring in each of these smaller areas were identified and recorded. These data were summarized into frequency distributions and the percentage of S-quadrats containing a given species and the variance of each species were estimated. The power law was applied to these estimates. The power law was used to evaluate the spatial heterogeneity and frequency of occurrence for each species in the grassland community. The lightly grazed grassland exhibited high spatial heterogeneity （caused by large plant size）, the highest species diversity, and a high occurrence of S. baicalensis. In contrast, the heavily grazed grassland exhibited high spatial heterogeneity （caused by patchy populations of small plant size）, low species diversity, and a low occurrence of S. baicalensis. We judged that the heavily grazed grassland was overgrazed and exclusion of livestock from the degraded areas is necessary for recovery.

Spatial Heterogeneity and Variability of a Large-Scale Vegetation Community Using a Power-Law Model

Spatial heterogeneity and stability are fundamental indices for describing vegetation communities. The spatial distribution characteristics of the vegetation in Nenjiang region of northeastern China were evaluated using a variance power-law model. The data fits the model well with estimates given for the levels of heterogeneity for not only single species but also the community as a whole. The linear regression indicates that the species in the community exhibit a consistently organized spatial pattern, as is often discovered in field surveys but rarely seen in artificial systems. The species deviations from the regression line, which exhibit a leptokurtic distribution, may reflect the variability of the community. Thus, the model provides a general tool for management and regulation of ecosystems, especially where there is human disturbances.

Fractals in Spatial Patterns of Vegetation Formations

The spatial distribution patterns of species are always scale-dependent and spatially self-similar in ecological systems. In this work, vegetation distribution data collected from the vegetation map of the Xigaze region was analyzed using a box-counting method. The power law of the box-counting dimension （DB） across a range of scales （5-160 km） confirms the fractal patterns for most vegetation formations, while the fluctuations of the scale-specific DB among the different abundance groups indicate limitations of fractal coherence. The fractal method is shown to be a useful tool for measuring the distribution patterns of vegetation formations across scales, which provides important information for both species and habitat conservation, especially in landscape management.

Vegetation Spatial Heterogeneity of Different Soil Regions in Inner Mongolia, China

The vegetation spatial heterogeneity and ecological characteristics in different soil regions were analyzed by surveying the vegetation in 12 different soil regions of Inner Mongolia, China, including coniferous-broadleaf deciduous forests, shrub, grassland, and desert regions with 1122 large 2 cm × 2 cm quadrats （actual size 30 km × 30 km, referred to as L-quadrat hereafter） in about 1.18 million km2. Each L-quadrat was divided into four small 1 cm × 1 cm quadrats （actual size 15 km × 15 km, S-quadrat）. The vegetation was analyzed based on the beta-binomial distribution to describe the frequency of occurrence and spatial heterogeneity for each kind of vegetation. The weighted average of the heterogeneity of all vegetation in the same soil region provides a measure of the soil regional landscape level heterogeneity which describes the spatial complexity of the regional landscape composition of the existing vegetation. Comparison of the vegetation characteristics in the 12 soil regions shows that, the calcic gray soil has the highest average vegetation type per quadrat. The largest soil region is calcic chestnut soil and has the most vegetation types. Every soil region has its own dominant vegetation sequence which dominates in occurrence and dominant vegetation types which dominates in spatial heterogeneity. For the Inner Mongolian vegetation, the weighted average of the heterogeneity is 0.60 and the vegetation diversity index is 4.47.

Spatial Heterogeneity of Vegetation in China

The spatial heterogeneity and ecological characteristics of 74 vegetation types and the lack of vegetation type within the 9.6 million km2 of Chinese territory were studied using data from the China vegetation map. The analysis used 877 large quadrats 10 mm×10 mm （actual size 100 km×100 km）, which covered about 8.77 million km^2. Each large-quadrat was divided into four small 5 mm×5mm quadrats （actual size 50 km×50 km）. The frequency of occurrence of all vegetation types was recorded in each small quadrat. The survey using the Shiyomi method of vegetation analysis based on the beta-binomial distribution was adopted to describe the frequency of occurrence and spatial heterogeneity for each kind of vegetation. The weighted average heterogeneity of all the vegetation types in the landscape provides a measure of the landscape level heterogeneity which describes the spatial intricacy of the existing vegetation composition. The maximum spatial vegetation heterogeneity was 0.8620 in the frigid-temperate coniferous forest of Larix （V1）, which dominates cold moist northeast China. The minimum spatial heterogeneity with a low occurrence was the Caragana tibetica in the gravel desert in the western Yellow River Hetao area. The minimum occurrence with a low spatial heterogeneity was the Monsoon rainforest on rock in Guangxi and Yunnan Provinces. The vegetation types on the Qing-Zang Plateau were found to be representative of Chinese vegetation because of the very high occurrence and spatial heterogeneity of these vegetation types. The weighted average of the heterogeneity was 0.677, while the vegetation diversity index was 3.29.