Browsing by Subject "starch"

Now showing 1 - 3 of 3
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    Effects Of Forage Preservation Methods, Dietary Starch Amount And Supplementation With Propionibacterium Freudenreichii Strain P169 On Transition Cow Health And Production, And Ketosis Prediction Tools.
    (2015-04) Sawall, Zachary
    Eighty PVC mini silos were used to evaluate corn silage fermentation characteristics with four homo- or heterofermentative inoculants. Freshly chopped corn silage was untreated Control (CON), or treated with Promote HN-3 (PHN), Promote LC-1000 (PLC), or Vigorsile EBL II (VEBL) before packing. Silos were opened at d 30, 60, 90 and 120 d. Averages over all time points, PLC and VEBL reduced pH compared to CON, and PLC had greatest lactic acid concentration and In vitro starch digestibility compared to CON, PHN, and VEBL. Ninety-six PVC mini silos were used to evaluate corn silage fermentation characteristics with four homo- or heterofermentative inoculants. Freshly chopped corn silage was untreated Control (CON), or treated with Promote AP (AP), Promote EBL (EBL), or Promote BP (BP) before packing. Silos were opened at d 30 and 90. After 90 d ensiled, corn silage with BP had higher pH, lower lactate, higher acetate concentration, and increased aerobic stability compared to CON, AP, and EBL. A 2 × 2 factorial randomized block design was used with 17 cows/treatment or 8 primiparous cows/treatment resulting in four treatments; 1) low starch + carrier (LSC), 2) low starch + Propionibacterium freudenreichii strain P169 (P169) (LSM), 3) high starch + carrier (HSC), 4) high starch + P169 (HSM). Starch amount was 15.5% and 26.7% prepartum and 20.1% and 29.7% postpartum. Multiparous cows fed HSM produced the greatest milk yield. Milk yield was similar for LSM and HSC. Feed efficiency was increased with P169. High starch tended to increase 3.5% fat corrected milk and energy corrected milk yield in primiparous cows. Also, high starch increased postpartum liver total lipid and triacylglycerol content. A retrospective analysis was conducted using 161 multiparous dairy cows to investigate easily measured, low cost variables correlated to subclinical ketosis in fresh cows. In addition, 328 cows from two commercial dairy farms were utilized to develop a ketosis prediction model (Pre-K) using day of calving data: colostrum yield (CY), body condition score, and parity. An increase in CY correlated with an increase in beta-hydroxybutrate concentration on d1 and 7. Pre-K model resulted in a sensitivity of 60% and specificity of 64% for predicting cows at risk for ketosis.
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    The impact of diurnal photosynthetic and starch branching enzyme activity on the composition and fine structure of barley starch.
    (2015-09) Goldstein, Avi
    In this work, the roles of two universal features of starch biosynthesis were investigated to better understand their impact on starch molecular structure. To investigate the impact of diurnal photosynthetic activity on starch fine structure, normal and waxy barley were cultivated in a greenhouse under normal diurnal, or constant light photosynthetic conditions. The impact of starch branching enzymes on starch structure was investigated by studying the lintners of barley starch, which had all known genes coding for starch branching enzymes (SBE I, SBE IIa, SBE IIb) suppressed in the grain resulting in a novel amylose-only starch (AOS). The structure of AOS lintners was compared to lintners from normal barley starch (NBS) and waxy barley starch (WBS). Unexpectedly, NBS and WBS displayed growth rings regardless of lighting regimes. It was observed that the molecular structure and composition of (NBS) was influenced by the diurnal lighting regime, as NBS contained lower quantities of amylose, and a lower ratio of long chain amylose:short chain amylose (determined by gel permeation chromatography) when cultivated under the diurnal lighting regime compared to the constant light regime. While the composition of WBS remained constant, higher relative crystallinity values (determined by X-ray diffraction), and greater crystalline quality (determined by differential scanning calorimetry) were observed when cultivated under the diurnal lighting regime. When considering the fine structure of amylopectin from NBS and WBS, differences in structure were observed when cultivated under the different lighting regimes. The structure of clusters and building blocks of amylopectin were investigated following their isolation by partial and complete hydrolysis with α-amylase from Bacillus amyloliquefaciens. Clusters of amylopectin from NBS and WBS cultivated under diurnal photosynthetic conditions were larger, and contained a greater number of building blocks compared to their counterparts cultivated in constant light conditions. AOS exhibited irregular morphological features and contained multi-lobed granules with a rough surface texture. When viewed by transmission electron microscopy (TEM), acid hydrolyzed components of AOS displayed strong textured aggregates with an organization not previous seen in other specimens, whereas NBS and WBS displayed expected stacks of elongated elements with a width of 5-7 nm, believed to represent crystalline amylopectin side chains viewed longitudinally. High performance anion-exchange chromatography of lintners at equivalent levels of acid hydrolysis (45 wt%) revealed that the average degree of polymerization of the AOS lintner was 21, substantially smaller than that of NBS and WBS (42). While NBS and WBS lintners displayed size distribution and chain length profiles expected of those from barley starch, the AOS lintner displayed a unique size distribution profile wherein a repeat-size of the molecules corresponding to 5-6 glucose residue was observed, which corresponds to the approximate number of residues required per turn of the helical structure of amylose. These data suggests that both diurnal photosynthetic activity, and the suppression of all genes coding for SBEs had significant impacts on the structure of barley starch granules.
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    Links between root carbohydrates and seasonal pattern of soil microbial activity of diverse european populations of Pinus sylvestris grown in a provenance plantation
    (Polish Botanical Society, 2003) Kaliszewska-Rokicka, Barbara; Oleksyn, Jacek; Zytkowiak, Roma; Reich, Peter B
    Activity of soil dehydrogenase (DHA) was measured in the mineral soil in a forest stand of 15 to 16-year-old Scots pine (Pinus sylvestris L.) from geographically diverse populations, as an indicator of biological activity of soil microorganisms, in a provenance experiment in Poland. The pine populations originated from six European countries (Sweden, Russia, Latvia, Poland, Germany, France) and differed widely in aboveground biomass and productivity. Soil DHA during two growing seasons showed pronounced seasonal variability, which was significantly related to the fine root concentration of nonstructural carbohydrates. Higher DHA was found in soil under canopies of the central and southern European populations than in those from more northern parts of the Scots pine range. Significant positive correlation between soil DHA and aboveground tree biomass suggest that these patterns most likely resulted from differences in carbon dynamics and productivity among populations.