Effects of Proportion of Dry Matter in Different Organs on Neutral Detergent Fiber Content in Silage Corn

[ Objective] To investigate the effects of proportion of dry matter of different organs in whole-plant dry matter on neutral detergent fiber （NDF） content in silage com. [ Metbod] A total of 36 crosses were developed from nine inbred lines, according to complete diallel crossing design. The NDF contents and proportion of dry matter in different organs were statistically analyzed. [ Result] The NDF contents were significantly different between different organs of silage corn, and the proportion of dry matter and NDF content had significant correlation in different organs. The wholeplant NDF content was positively correlated with the proportion of dry matter in straw, stem and leaf as well as bract and spike-stalk, but it was negatively correlated with the proportion of dry matter in ear. [Conclusion] TO reduce NDF content in straw and to increase grain yield are efficient ways to improve quality of silage corn.

Effects of Neutral Detergent Soluble Fiber and Sucrose Supplementation on Ruminal Fermentation, Microbial Synthesis, and Populations of Ruminal Cellulolytic Bacteria Using the Rumen Simulation Technique (RUSITEC)

We evaluated the effects of neutral detergent soluble fiber （NDSF） and sucrose supplementation on ruminal fermentation, microbial synthesis, and populations of ruminal cellulolytic bacteria using the rumen simulation technique （RUSITEC）. The experiment had a 2x2 factorial design with two dosages of sucrose, low （ca. 0.26 g d-1, low-sucrose） and high （ca. 1.01 g d-1, high-sucrose）, and two dosages of supplied NDSF, low （1.95 g d-1, Iow-NDSF） and high （2.70 g d-1, high-NDSF）. Interactions between NDSF and sucrose were detected for xylanase activity from solid fraction and apparent disappearance of neutral detergent fiber （NDF） and hemicellulose, with the lowest values observed for high-NDSF and high-sucrose treatment. Supplemental NDSF appeared to increase the molar proportion of acetate and reduce that of butyrate; however, the effects of supplemental sucrose on VFA profiles depended upon NDSF amount. There was a NDSFxsucrose interaction for the production of methane. High-NDSF fermenters had lower ammonia-N production, greater daily N flow of solid- associated microbial pellets and total microorganisms, and greater microbial synthesis efficiency compared with low- NDSF fermenters. Supplementation with NDSF resulted in an increase in 16S rDNA copies of Ruminococcusflavefaciens and a reduction in copies of Ruminococcus albus. Supplementation with sucrose tended to increase the 16S rDNA copies ofR. albus from liquid fraction, but did not affect daily total microbial N flow and cellulolytic bacterium populations from solid fraction. These data indicate that the effects of the interaction between NDSF and sugars on ruminal fermentation and fiber digestion should be taken into account in diet formulation. Ruminal fermentation and metabolism of sugars warrant further investigation.

Replacement of Forage Fiber Sources with Dried Distillers Grains with Solubles and Corn Germ Meal in Holstein Calf Diets

This study was carried out to determine the effect of replacement of forage fiber sources from alfalfa and Leymus chinensis with nonforage fiber sources（NFFS） from dried distillers grains with solubles and corn germ meal on calves growth, rumen development and blood parameters. 48 female and 12 male calves（（110.55±15.36） kg of body weight and 12 wk of age） were assigned randomly to four dietary treatments（15 calves/treatment） in a completely randomized design. Experimental diets were： 0% NFFS（control）, 9% NFFS（group 1）, 18% NFFS（group 2）, 27% NFFS（group 3）, and contained equivalent neutral detergent fiber and total digestible nutrients, respectively. The dry matter intake was similar among diets, averaging 3.33 kg d-1, and no differences were detected for body weight, withers height, body length and heart girth. In addition, the development of rumen, reticulum, omasum and abomasum also were similar among diets. Dry matter, crude protein, and neutral detergent fiber digestibilities increased with the increasing levels of NFFS in the experimental diets, but had no significant effect. Blood urea nitrogen, total protein and glubulin were not affected by the dietary treatment, but group 3 resulted in the highest（P〈0.05） concentrations of glucose and the lowest（P〈0.05） concentrations of triglycerides and albumin. In conclusion, dried distillers grains with solubles（DDGS） and corn germ meal（CGM） were available and alternative fiber sources for Holstein calf diets.

Effects of different sources of carbohydrates on intake, digestibility, chewing, and performance of Holstein dairy cows

To investigate the effects of different sources of carbohydrates on intake, digestibility, chewing, and performance, nine lactating Holstein dairy cows （day in milk= 100±21 d; body weight=645.7 ± 26.5 kg） were allotted to a 3 × 3 Latin square design at three 23-d periods. The three treatments included 34.91% （B）, 18.87% （BC）, and 18.86% （BB） barley that in treatment B was partially replaced with only corn or corn plus beet pulp in treatments BC and BB, respectively. The concentration of starch and neutral detergent soluble carbohydrate varied （22.2, 20.2, and 14.5; 13.6, 15.9, and 20.1% of DM in treatments B, BC, and BB, respectively）. Cows in treatment BB showed a higher DMI and improved digestibility of DM, NDF, and EE compared with treatments B or BC Ruminal pH was higher in cows fed on BB （6.83） compared with those that received B or BC treatments （6.62 and 6.73, respectively）. A lower proportion of propionate accompanied the higher pH in the BB group; however, a greater proportion of acetate and acetate： propionate ratio was observed compared with cows fed either on the B or BC diet. Moreover, cows fed on the BB diet showed the lowest ruminal passage rate and longest ruminal and total retention time. Eating time did not differ among treatments, rumination time was greater among cows fed on the BB diet compared with the others, whereas total chewing activity was greater than those fed on BC, but similar to those fed on B. The treatments showed no effect on milk yield. Partially replacing barley with corn or beet pulp resulted in an increase in milk fat and a lower protein concentration. Changing dietary NFC with that of a different degradability thus altered intake, chewing activity, ruminal environment, retention time or passage rate, and lactation performance. The results of this study showed that beet pulp with a higher NDF and a detergent-soluble carbohydrate or pectin established a more consistent ruminal mat than barley and corn, thus resulting in higher mean retention time and chewing activity, whereas no changes in 3.5% ECM and milk fat were observed.

Improvement of Feeding Value of Rapeseed Meal by Mixed Solid State Fermentation

[Objective] To optimize solid state fermentation conditions of rapeseed meal and thus to reduce glucosinolates and neutral detergent fibers by mixed cultures of Aspergillus oryzae and Tnchoderrna viride. [ Method ] The optimal fermentation conditions were determined by single factor test and orthogonal design. [ Result J The optimum fermentation conditions are as following: inoculum weight ratio (Aspergillus oryzae vs Trichoderma vinde), 1:1 ; inoculum size, 30% ; water content, 40% ; fermentation time, 96 h; and fermentation temperature, 30℃. Under these conditions, glucosinolates were reduced by 90.71% and neutral detergent fibers were degraded by 20.65%. [ Condusion] In laboratory, solid state fermentation with Aspergillus oryzae and Trichoderrna viride can be used to produce high-quality rapeseed meal.

Analysis of Some Important Forage Quality Attributes of Southeastern Wildrye (Elymus glabriflorus) Using Near-Infrared Reflectance Spectroscopy

Southeastern wildrye (Elymus glabriflorus, Vasey ex L.H. Dewey) is a cool-season, perennial grass native to southeastern United States. Recently, there is a growing interest in its development as a grazing and haying forage crop due to its wide area of adaptation across this region. Consequently, there is a great need for the evaluation of its forage quality by rapid, but accurate analytical methods like Near-Infrared Reflectance Spectroscopy (NIRS). In this study, acceptable NIRS calibration models were developed for: dry matter, DM (n = 113, R2 = 0.904, RSCD = 2.54, RSCIQ = 4.65);crude protein, CP (n = 113, R2 = 0.974, RSCD = 5.16, RSCIQ = 5.92);acid detergent fiber, ADF (n = 116, R2 = 0.896, RSCD = 2.35, RSCIQ = 1.28);neutral detergent fiber, NDF (n = 118, R2 = 0.934, RSCD = 2.53, RSCIQ = 3.38);digestible dry matter, DDM (n = 116, R2 = 0.895, RSCD = 2.36, RSCIQ = 1.35);dry matter intake, DMI (n = 115, R2 = 0.924, RSCD = 2.40, RSCIQ = 2.53);and relative feed value, RFV (n = 114, R2 = 0.932, RSCD = 2.94, RSCIQ = 2.81). Prediction of independent validation sets yielded good agreement between the NIRS predicted values and the laboratory reference values for each of: DM (n = 53, R2 = 0.831, RPD = 2.45, RPIQ = 4.24);CP (n = 57, R2 = 0.967, RPD = 5.37, RPIQ = 7.16);ADF (n = 49, R2 = 0.895, RPD = 2.97, RPIQ = 1.51);NDF (n = 53, R2 = 0.928, RPD = 3.75, RPIQ = 4.22);digestible dry matter, DDM (n = 55, R2 = 0.860, RSCD = 265, RSCIQ = 1.15);dry matter intake, DMI (n = 156, R2 = 0.845, RSCD = 2.48, RSCIQ = 2.11);and relative feed value, RFV (n = 55, R2 = 0.916, RSCD = 3.45, RSCIQ = 3.04) contents, indicating that all seven calibration models had good quantitative information. Therefore, precise, accurate, and rapid analysis of these important forage quality attributes of southeastern wildrye can be routinely done using the developed NIRS calibration models.

Moisture Content and Nutrient Composition of Alfalfa under Different Drying Methods

[Objective] The paper was to study the effects of different drying methods on moisture content and nutrient composition of alfalfa.[Method] Alfalfa collected from the same piece of land in early flowering period were dried through three different drying methods, solar drying,outdoor drying in the sun and outdoor drying in the shade, and the effects of different drying methods on contents of moisture, crude protein, crude ash and neutral detergent fiber（NDF） were measured. [Result] The moisture evaporation rate of different drying methods over the same period successively were solar drying 〉 outdoor drying in the sun 〉 outdoor drying in the shade. The crude protein content of alfalfa was the highest through solar drying（P〈0.05）, followed by outdoor drying in the shade, and the crude protein content through outdoor drying in the sun was the lowest. Under the condition of different moisture contents, the crude protein content of dried samples through outdoor drying in the sun decreased by 6.86%-22.43% compared to solar drying, and that through outdoor drying in the shade reduced by 4.92%-17.20%. Under the same moisture content, the crude ash content successively were outdoor drying in the shade 〉 outdoor drying in the sun 〉 solar drying; the crude ash content of alfalfa through solar drying was 3.72%-19.22% lower than outdoor drying in the sun, and 8.12%-29.93% lower than outdoor drying in the shade. The NDF content of alfalfa through outdoor drying in the sun was the highest, significantly higher than the other two drying methods（ P〈0.05）. The NDF content through solar drying was the lowest, 9.08%-27.25% lower than outdoor drying in the sun, and 4.84%-24.84% lower than outdoor drying in the shade. [Conclusion] The paper will provide some references for selection of appropriate alfalfa drying method.