Higher Neutral Detergent Fiber Concentrations Research Articles

Ensilability and Nutritive Value of Sweet Sorghum and Sweet Pearl Millet Bagasse as Affected by Different Methods of Carbohydrate Extraction for Eventual Ethanol Production

HighlightsJuice extraction resulted in a decrease in the nutritive value of the bagasse as compared with the initial biomass.Silages made from the second pressing bagasse were well conserved.Sweet sorghum silage has a better nutritive value than sweet pearl millet.Abstract. Pressing the biomass of sweet sorghum and sweet pearl millet in-field is one of the suggested options for bioethanol production. The extracted juice can be delivered to an ethanol plant, and the bagasse (pressing residue) can be used for ruminant feeding. Efficient carbohydrate extraction is highly important for good ethanol yield. However, enough carbohydrates must remain in the bagasse for its adequate conservation as silage. In this study, the ensilability and the chemical composition of the second pressing bagasse of sweet sorghum and sweet pearl millet were investigated. The bagasse was obtained following a second pressing of the first pressing bagasse after its impregnation with water based on three water:bagasse ratios (0.5, 1, and 1.5). Results indicated that water:bagasse ratio did not affect water-soluble carbohydrate (WSC) extraction for both crops. The second pressing bagasse of sweet sorghum and sweet pearl millet contained 80.5 ±4.6 and 60 ±4.6 g of WSC kg-1 dry matter (DM), respectively. The second pressing bagasse of both crops had reduced nutritive value compared to the initial biomass, i.e., higher neutral detergent fiber (NDF) and acid detergent fiber (ADF) concentrations along with lower non-structural carbohydrate (NSC) concentration, in vitro true digestibility of DM (IVTD), and in vitro NDF digestibility (NDFd). The second pressing bagasses of both crops also showed good ensilability, but sweet sorghum bagasse silages were of better nutritive value than sweet pearl millet bagasse silages (ADF = 446.2 ±3.7 vs. 463.2 ±3.7 g kg-1 DM, IVTD = 813.8 ±3.4 vs. 708.8 ±6.8 g kg-1 DM, and NDFd = 741.8 ±4.8 vs. 596.2 ±8.5 g kg-1 NDF, respectively). The water:bagasse ratio used for bagasse impregnation before the second pressing only affected the NDF concentration of silages, as a higher NDF concentration was obtained with a water:bagasse ratio of 1.5. Sweet sorghum and sweet pearl millet can be considered dual-purpose crops; the extracted juice can be fermented into ethanol, and the second pressing bagasse can be used to make good-quality silage. Keywords: Bagasse impregnation, Nutritive value, Silage, Sweet pearl millet, Sweet sorghum, Water-soluble carbohydrates.

Influence of fiber degradability of corn silage in diets with lower and higher fiber content on lactational performance, nutrient digestibility, and ruminal characteristics in lactating Holstein cows

The effect of neutral detergent fiber (NDF) degradability of corn silage in diets containing lower and higher NDF concentrations on lactational performance, nutrient digestibility, and ruminal characteristics in lactating Holstein cows was measured. Eight ruminally cannulated Holstein cows averaging 91 ± 4 (standard error) days in milk were used in a replicated 4 × 4 Latin square design with 21-d periods (7-d collection periods). Dietary treatments were formulated to contain either conventional (CON; 48.6% 24-h NDF degradability; NDFD) or brown midrib-3 (BM3; 61.1% 24-h NDFD) corn silage and either lower NDF (LNDF) or higher NDF (HNDF) concentration (32.0 and 35.8% of ration dry matter, DM) by adjusting the dietary forage content (52 and 67% forage, DM basis). The dietary treatments were (1) CON-LNDF, (2) CON-HNDF, (3) BM3-LNDF, and (4) BM3-HNDF. Data were analyzed as a factorial arrangement of diets within a replicated Latin square design with the MIXED procedure of SAS (SAS Institute Inc., Cary, NC) with fixed effects of NDFD, NDF, NDFD × NDF, period(square), and square. Cow within square was the random effect. Time and its interactions with NDFD and NDF were included in the model when appropriate. An interaction between NDFD and NDF content resulted in the HNDF diet decreasing dry matter intake (DMI) with CON corn silage but not with BM3 silage. Cows fed the BM3 corn silage had higher DMI than cows fed the CON corn silage, whereas cows fed the HNDF diet consumed less DM than cows fed the LNDF diet. Cows fed the BM3 diets had greater energy-corrected milk yield, higher milk true protein content, and lower milk urea nitrogen concentration than cows fed CON diets. Additionally, cows fed the BM3 diets had greater total-tract digestibility of organic matter and NDF than cows fed the CON diets. Compared with CON diets, the BMR diets accelerated ruminal NDF turnover. When incorporated into higher NDF diets, corn silage with greater in vitro 24-h NDFD and lower undegradable NDF at 240 h of in vitro fermentation (uNDF240) allowed for greater DMI intake than CON. In contrast, for lower NDF diets, NDFD of corn silage did not affect DMI, which suggests that a threshold level of inclusion of higher NDFD corn silage is necessary to observe enhanced lactational performance. Results suggest that there is a maximum gut fill of dietary uNDF240 and that higher NDFD corn silage can be fed at greater dietary concentrations.

Vegetation diversity, growth, quality and decomposition in managed grasslands

The relationship between vegetation growth rate, quality, litter decomposition and diversity was investigated in four grazed grasslands differing in topography, management and fertility in the southern North Island of New Zealand. Vegetation samples were clipped at two sampling times (summer and autumn) from 0.5 m 2 areas excluded from grazing. Crude protein (CP), in vitro dry matter digestibility (IVDMD), neutral detergent fiber (NDF), average daily growth (ADG) rate, species composition and the relative extent of tissue degradation by soil microorganisms were determined for the vegetation samples. It was hypothesized that vegetation diversity would be negatively related with measures of vegetation growth, quality and decomposition. Comparisons made across all environmental and management conditions agreed with the hypotheses. Higher vegetation diversity was associated with lower ADG rate, lower CP concentrations, lower IVDMD and higher NDF concentrations. Comparisons within management regimes (MR), however, were less consistent and possible reasons for this are examined. Litter decomposition extent was closely related to the tissue quality characteristics of the vegetation, especially NDF concentration, but not species diversity. The observed local-scale relationships between the vegetation diversity, growth, quality and decomposition characteristics were contended to be largely the result of the influence of environmental resource richness on community structure of the managed grasslands studied. There is a need to promote a functionally diverse plant community over the entire managed area rather than promoting high localized species diversity within grasslands.

Effects of Replacing Forage Fiber or Nonfiber Carbohydrates with Dried Brewers Grains

Four primiparous Holstein cows in late lactation were used in a 4 × 5 Youden square design. Each cow was fitted with ruminal, duodenal, and ileal cannulas. Treatments were a control diet with a high concentration of forage, a control diet with a low concentration of forage, and three diets in which dried brewers grains replaced a portion of the forage, concentrate, or both. Cows were fed and milked twice daily in 14-d periods. Chromic oxide and Yb (soaked in acid) were used as markers for digesta flow and rate of passage, respectively. No significant differences in ruminal pH or rates of passage caused by treatment were detected. Although brewers grains had slower digestion rates of neutral detergent fiber (NDF) in situ and faster passage rates than did alfalfa, brewers grains had minor effects on site of NDF digestion. Intake of dry matter was depressed by the higher NDF concentrations in diets in which brewers grains replaced concentrate, but a long-term feeding study is needed to verify this conclusion. Although brewers grains did not appear to be very effective at stimulating milk fat percentage, dry matter intake was maintained when brewers grains replaced forage, and it appears that brewers grains can successfully replace a portion of the forage NDF in the diets of lactating cows.

In vitro digestion kinetics of neutral detergent fiber extracted from Tifton 85 and Coastal bermudagrasses

Hays used to compare the digestion kinetics of neutral detergent fiber (NDF) were Tifton 85 bermudagrass (T85) harvested after 3.5 or 7 weeks of growth, a second cutting of T85 harvested after 3.5 weeks of regrowth, and Coastal bermudagrass (CBG) harvested after 4 weeks of growth. Neutral detergent fiber extracted from the hays was exposed to in vitro digestion and the digesta analyzed for their NDF content. The in vitro dry matter disappearance for the first (63.6%) and second (59.9%) cutting of 3.5-weeks old T85 was similar but higher than that for T85 harvested after 7 weeks of growth (48.7%) or CBG harvested after 4 weeks of growth (52.0%). In vitro NDF digestion at 72 h of incubation for T85 harvested at 3.5 week (74.5%) was similar to that of 3.5-weeks T85 regrowth (67.4%), but higher than that of CBG (63.7%) or 7-weeks T85 (53.7%). After fitting a nonlinear model to the data, T85 harvested at 3.5 week had a higher ( P<0.05) potentially digestible fraction of NDF. Extraction of NDF from the hays increased the potentially digestible fraction of NDF. In summary, Tifton 85 bermudagrass harvested at 3.5 week had a higher NDF concentration, and higher NDF digestion than did Coastal bermudagrass harvested at 4 week.

Stratiform Analysis of Growth, Total Nitrogen, Free Amino Acid and Neutral Detergent Fiber Concentration of New Shoots in Mechanically-plucked Tea(Camellia sinensis L.) Bush.

Some factors which might relate to yield and quality were inverstigated by stratiform analysis in order to estimate the most suitable plucking height in the mechanically-plucked tea bush. During a period of new shoot growth of the first crop in 1992, new shoots were harvested at 1cm intervals from the top to the bottom of each tea bush. Weights of leaves and stems were heavier at the lower layers than the upper layers. The total nitrogen concentration was higher at thc upper layers. The free amino acid concentration was higher at the middle layers in the early harvest, and was higher at the upper layers in the late harvest. The neutral detergent fiber concentration was higher at thc lower lavers. These results show that at the upper plucking height, yield decreases but quality is enhanced. On the basis of these results, an attempt was made to modify the qualitative deterioration caused by the delay in harvesting time. In the plucking at the last skiffing height, the harvest on May 8th showed higher neutral detergent fiber concentration and less total nitrogen and free amino acid concentration than the harvest on May 4th. However, when plucked 2∼4cm higher on May 8th, the harvest showed the same level of chemical concentrations as the plucking at the last skiffing height on May 4th.

Depression of Forage Quality of Alfalfa Leaves and Stems by Acyrthosiphon kondoi (Homoptera: Aphididae)

ABSTRACf ACYTthosiphon kondoi Shinji is a major pest of alfalfa (Medicago sativa L.). Susceptible seedling plants are killed by A. kondoi, and established plants suffer yield loss by stunting. Information is meager on the influence of A. kondoi infestation or host plant resistance on forage quality of alfalfa leaves and stems. In a controlled environment, the forage quality (including phenolic monomers)of alfalfa germplasmsKSI53P4and KS153BA3P4 (susceptible and resistant to A. kondoi, respectively) with and without A. kondoi infestation was compared. Leaves infested with A. kondoi had lower concentrations of crude protein and true in vitro digestible dry matter (TIVDDM) than uninfested leaves of controls, but infested stems had higher crude protein concentration. Stems and leaves infested with A. kondoi had higher neutral detergent fiber concentrations than did those of uninfested controls. Infested stems of KS153BA3P4had more syringic acid than did infested stems of KS153P4 and uninfested controls. However, A. kondoi infestation did not alter TIVDDM or digestible neutral detergent fiber of stems. The A. kondoi-resistant KS153BA3P4had more neutral detergent fiber in leaves but lower TIVDDM and digestible neutral detergent fiber in stems than susceptible KS153P4.Infestation of alfalfa for short time periods by A. kondoi decreased the nutritive value of leaves and stems.

Responses of Kentucky-31 Tall Fescue to Varying Forcipata local1 DeLong and Caldwell Infestation Levels: Field Study 2

Relationships between leafhopper feeding and the resulting effects on forage grasses have not been well defined. Therefore, the morphological and physiological responses of Kentucky-31 tall fescue to various population densities of Forcipata loca were examined in a 2-year field cage experiment. The detrimental effect of F. loca on tall fescue was reflected primarily in reduced forage quality rather than in yield reduction. Significantly higher neutral detergent fiber concentrations, significantly lower water-soluble carbohydrate concentrations, and significantly lower in vitro digestible dry-matter concentrations were observed. Increased fiber and decreased cell content reduced forage digestibility.