113 research outputs found
Effects of Monensin on metabolic profile and feeding behavior of transition dairy cows
Thirty-two Holstein transition cows were used to determine the effects of monensin (Rumensin, Elanco Animal Health, Greenfield, IN; 400 mg/cow daily) on metabolism and feeding behavior. Cows were assigned randomly, based on calving date, to control or monensin treatments (n = 16 per treatment) 21 days before their expected calving date, and cows remained on treatments through 21 days in milk. Feeding behavior and water intake data were collected daily. Blood samples were collected at 8 different time points during the experimental period. Monensin decreased mean and peak plasma ketone concentrations, and also decreased time between meals before and after calving. No effects of monensin supplementation were observed on milk production or other metabolic traits. Furthermore, we observed no treatment effects on disease incidence, although sample size was small for detecting such effects.; Dairy Day, 2011, Kansas State University, Manhattan, KS, 2011; Dairy Research, 2011 is known as Dairy Day, 201
Mineralogia e cristalografia da fração argila de horizontes coesos de solos nos tabuleiros costeiros
Root-shoot growth interactions of sorghum (sorghum bicolor l moench) in response to mechanical impedance
Tanzania Journal of Agricultural Sciences 2000, VoI.3(1) :11-20Soil mechanical impedance has a widespread influence on plant organ expansion, penetration, and
growth. Studies on root-shoot intera'ctions in relation to mechanical impedance have only investigated
the effect on shoots of mechanical impedance imposed on roots. The aim of the reported study was therefore
to fill the identified iap in knowledge, including an investigation into all root-shoot interations in response
to mechanical impedance. Individual pregerminated sorghum (Sorghum bicolor L. Moench)
seeds cultivar ICSV-I12 were grown for 8 days in a growth room in seven replicate cylinders per treatment.
Treatments were: (a) impeded root and impeded shoot (II), (b) impeded root and unimpeded shoot
(lU), (c) unimpeded root and impeded shoot (VI), and (d) the control, in which both the root and shoot
systems were unimpeded (UU). The impeding growth medium was a mixture of sand and vermiculite
packed to give a penetration resistance (PR) of 1.18 MPa below the seed and 0.32 MPa above the seed.
Control cylinders were completely packed with expanded vermiculite to a bulk density of 0.2 Mg m-3 giving
aPR ofO. 025 MPa. Matnc suction was 5.kPa in both media. Results were that: (i) Impedance tg the
shoot significantly (P < 0.05) delayed emergence, more so when the root was, also impeded. (ii) Shoots
emerging through a mechanically impeding layer, had significantly greater extension rates after emergence
than unimpeded ones. (iii) Mesocotyls became significantly thicker only when (he root systems
were impeded. (iv) Impeding the shoot system, significantly increased root extension rate. (v) The
length of the first internode, the number of leaves and the spacing of lateral roots were not changed by
any of the treatments. Root-shoot signalling is suggested as one ofthefactors responsiblefor these interactions.
Generally, our findings indicate that mechanical impedance which may be caused by sUrface
crusting and hardsetting soils and shallow tilth achieved with a hand hoe results in poor crop establishment
and probably total. crop failure
A Technique for Controlling Matric Suction on Filter Papers used in seed Gennination Tests, Imbibition, root and shoot Growth studies
Tanzania Journal of Agricultural Sciences1998, Vol 1(1) : 14-27Moist filter papers are widely usedfor seed gennination tests but their water confent and matric suction
are not usually controlled. A technique for controlling filter paper matric suction is described and
usedfor germination studies involving fresh and aged sorghum seed (Sorghummcolor (L) Moench).
Filter papers wetted to matric suctions of 0.1 ,land 10 kPa were used to study germination, root and
shoot growth rate offour cultivars (M35-1, ICSV-1l2, CSH-9 & CSH-ll) of sorghum at 25°C. Time
to germination, root and shoot growth were all affected by the increase in matric suction from either
0.1 to 1, or 1 to 10 kPa. Root and shoot emergence ratefrom seeds, decreased with increasing matrie
suction. The increase in matric suction resulted in significant reductions (P= O. 05) in final root and
shoot length. Final germination percentage was not affected by variation§ in matric suction. Ageing
delayed shoot emergence. Seedlings with emetged shoots were significantly fewer at 10 kPa as
compared to 1 kPa only for aged seed, and for all cultivars except Icsv-i 12. A link between matrie
suction, seed-liquid contact area and the rate of water uptake by seed is demonstrated. We conclude
from this study: that changes in the matric suction on filter paper even at the wet end will cause
variations in gennination rate and therefore ought to be controlled during germination tests. Seed
tests separated in time and space can not be compared iffilter paper matric suction is not controlled
Recommended from our members
Analysis of gamma-ray spectra from foils activated in a range-thick lead target by 800-MeV protons. Final technical report
Approximately 400 gamma-ray spectra have been analyzed to obtain the types and quantities of radioisotopes produced when 800-MeV protons interact with a range-thick lead target. These spectra were obtained from the radioactive decay of product isotopes in lead disks placed at various depths and radial positions within the target. These spectra were analyzed with the computer code HYPERMET and the photopeak areas were reduced to nuclei produced per incident proton per cubic centimeter of material. Product nuclei ranged from atomic mass 160 to mass 206 and over a range of half lives from a few minutes to several weeks. The results of this analysis have been outlined in this report and transmitted on computer disk to Los Alamos National Laboratory. The consistency of these analyses have been confirmed by a comparison of photopeak areas obtained at LANL with the computer code GAMANAL with those from HYPERMET for two gamma-ray spectra. Also, the nuclear production per proton per cm{sub 3} obtained from these two spectra analyzed both at LANL and at EKU have been found to agree to within the statistical accuracy of the peak-fitting programs. This analysis of these 400 gamma-ray spectra has determined the nuclear production per incident proton per cm{sub 3} at five regularly-spaced radial positions and depths up to 40 cm into a range-thick lead target
Root-shoot growth interactions of sorghum (sorghum bicolor l moench) in response to mechanical impedance
Tanzania Journal of Agricultural Sciences 2000, VoI.3(1) :11-20Soil mechanical impedance has a widespread influence on plant organ expansion, penetration, and
growth. Studies on root-shoot intera'ctions in relation to mechanical impedance have only investigated
the effect on shoots of mechanical impedance imposed on roots. The aim of the reported study was therefore
to fill the identified iap in knowledge, including an investigation into all root-shoot interations in response
to mechanical impedance. Individual pregerminated sorghum (Sorghum bicolor L. Moench)
seeds cultivar ICSV-I12 were grown for 8 days in a growth room in seven replicate cylinders per treatment.
Treatments were: (a) impeded root and impeded shoot (II), (b) impeded root and unimpeded shoot
(lU), (c) unimpeded root and impeded shoot (VI), and (d) the control, in which both the root and shoot
systems were unimpeded (UU). The impeding growth medium was a mixture of sand and vermiculite
packed to give a penetration resistance (PR) of 1.18 MPa below the seed and 0.32 MPa above the seed.
Control cylinders were completely packed with expanded vermiculite to a bulk density of 0.2 Mg m-3 giving
aPR ofO. 025 MPa. Matnc suction was 5.kPa in both media. Results were that: (i) Impedance tg the
shoot significantly (P < 0.05) delayed emergence, more so when the root was, also impeded. (ii) Shoots
emerging through a mechanically impeding layer, had significantly greater extension rates after emergence
than unimpeded ones. (iii) Mesocotyls became significantly thicker only when (he root systems
were impeded. (iv) Impeding the shoot system, significantly increased root extension rate. (v) The
length of the first internode, the number of leaves and the spacing of lateral roots were not changed by
any of the treatments. Root-shoot signalling is suggested as one ofthefactors responsiblefor these interactions.
Generally, our findings indicate that mechanical impedance which may be caused by sUrface
crusting and hardsetting soils and shallow tilth achieved with a hand hoe results in poor crop establishment
and probably total. crop failure
- …