Regrowth Research Articles

Use of a combination of two clustering and tree algorithms for investigating and predicting alfalfa yield under different conditions of deficit irrigation

The largest amount of water consumption in Iran is related to agriculture. Considering that Iran has suffered a drought in recent years, the optimal use of water is necessary, especially in the agricultural sector. For this reason, in this research, the deficit irrigation regarding alfalfa crop was investigated. Alfalfa was cultivated in three years with four replications. Deficit irrigation methods including 40 %, 70 % and 100 % full irrigation (FI) were employed at different stages of alfalfa growth. First, crop per drop (CPD), benefit per drop (BPD) and net benefit per drop (NBPD) values related to alfalfa were clustered. The results of clustering were introduced to the tree algorithm as target data. The tree algorithm predicted the target data according to the factors of 1) the type of cropping year, 2) the time of harvest and 3) the level of deficit irrigation at different stages of alfalfa growth. According to the results of the combination of two algorithms, it was found that The lowest values of CPD, BPD and NBPD are equal to 1.2 (kg/m3), 125 (1000 Rial/m3) and 115 (1000 Rial/m3) respectively in the second harvest and deficit irrigation which was predicted in the two regrowth (RG) and budding (BU) stages. The highest values of CPD, BPD and NBPD are equal to 1.8 (kg/m3), 185 (1000 Rial/m3) and 175 (1000 Rial/m3) respectively in the third harvest and deficit irrigation which was predicted in the branching stage (BR). Thus, to increase the yield, it is better not to perform severe deficit irrigation at RG and BU stages. Also, according to the predictor importance of the software, it was found that the three factors of harvest time, BU and the type of cropping year had the greatest effect on the prediction, respectively.

What characteristics of the economy drive the growth of modern renewable energy? Evidence from 52 countries’ panel data

ABSTRACT This study probes the relationship between the characteristics of the economy with the growth of modern renewable sources in 52 countries for the period 2015–2021. The Cross-Sectional Auto Regressive Distributed Lag (CS-ARDL) results suggest that growth in industrialization positively impacts the growth of renewable energy both in the short and long run. CO2 emission reduction also positively helps RE growth in the short run.

Chemoradiation and consolidation chemotherapy for rectal cancer provides a high rate of organ preservation with a very good long-term oncological outcome: a single-center cohort series

AimTo report long-term oncological outcomes and organ preservation rate with a chemoradiotherapy-consolidation chemotherapy (CRT-CNCT) treatment for locally advanced rectal cancer (LARC).MethodRetrospective analysis of prospectively maintained database was performed. Oncological outcomes of mid-low LARC patients (n=60) were analyzed after a follow-up of 63 (50–83) months. Patients with clinical complete response (cCR) were treated with the watch-and-wait (WW) protocol. Patients who could not achieve cCR were treated with total mesorectal excision (TME) or local excision (LE).ResultsThirty-nine (65%) patients who achieved cCR were treated with the WW protocol. TME was performed in 15 (25%) patients and LE was performed in 6 (10%) patients. During the follow-up period, 10 (25.6%) patients in the WW group had regrowth (RG) and 3 (7.7%) had distant metastasis (DM). Five-year overall survival (OS) and disease-free survival (DFS) were 90.1% and 71.6%, respectively, in the WW group. Five-year OS and DFS were 94.9% (95% CI: 88–100%) and 80% (95% CI: 55.2–100%), respectively, in the RG group. For all patients (n=60), 5-year TME-free DFS was 57.3% (95% CI: 44.3–70.2%) and organ preservation-adapted DFS was 77.5% (95% CI: 66.4–88.4%). For the WW group (n=39), 5-year TME-free DFS was 77.5% (95% CI: 63.2–91.8%) and organ preservation-adapted DFS was 85.0% (95% CI: 72.3–97.8%).ConclusionCRT-CNCT provides cCR as high as 2/3 of LARC patients. Regrowths, developed during follow-up, can be successfully salvaged without causing oncological disadvantage if strict surveillance is performed.

Identification of QTL associated with cold acclimation and freezing tolerance in Zoysia japonica

AbstractZoysiagrasses (Zoysia spp.) are relatively low‐input and warm‐season turfgrasses which have grown in popularity in the United States since their introduction in the 1890s. Over 30 improved zoysiagrass cultivars were released in the past three decades, but many lack freezing tolerance and their use is limited to warm‐humid climates. Understanding the genetic controls of winter hardiness and freezing tolerance in zoysiagrass could considerably benefit the breeding efforts to increase tolerance to freezing stress. In the present study, controlled environment acclimation and freezing tests were used to evaluate a Meyer × Victoria zoysiagrass mapping population for post‐freezing surviving green tissue (SGT) and regrowth (RG). Quantitative trait loci (QTL) mapping analysis identified nine QTL associated with SGT, eight QTL linked to RG, and 22 QTL common in both traits, accounting for between 6.4 and 12.2% of the phenotypic variation. Eleven regions of interest overlapped with putative winter injury QTL identified in a previous field study. Upon sequence analysis, homologs of several abiotic response genes were found underlying these overlapping QTL regions. The homologs of these gene encode transcription factors, cell wall modification‐related proteins, and defense signal transduction‐related proteins. After further validation, these QTL and their associated markers have potential to be used in future breeding efforts for the development of a broader pool of zoysiagrass cultivars capable of surviving in cold climates.

The limits of renewable energy

<abstract> Planet Earth is simultaneously approaching a number of ecological and resource limits. The resulting uncertainties will heavily impact future energy choices, both the level of primary energy used globally and the shares of fossil, renewable and nuclear fuels in the energy mix. This paper reviews the possible futures for the various types of renewable energy. To be viable, all potential energy sources must be assessed on their energy return on energy invested (energy return). Given that renewable energy RE growth is considered important for sustainability reasons, renewable energy must be assessed on its ecologically sustainable or 'green' energy return, which includes the energy costs of ecosystem maintenance as input energy costs. The green energy return is accordingly much lower than the conventional value, so that ecologically sustainable renewable energy is unlikely to deliver anything near existing global energy use. The paper further argues that such constraints on renewable energy growth rates mean it cannot be a timely response to global climate change. The paper concludes that energy reductions will be essential, mainly in high energy use countries. </abstract>

Abstract A02: Photodynamic therapy in combination with immunotherapy enhances the long-term cure of bladder cancer in tumored mice

Abstract Introduction and Objectives: To investigate the utility of combination approach for treating bladder cancer, mice bearing UMUC3 (human transitional cell carcinoma) and T24 (human urinary bladder) tumors were treated with HPPH (2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a)-PDT alone and in combination with BCG. The HPPH, a multifunctional agent, was selected as a photosensitizer because of its higher tumor avidity, improved fluorescence imaging ability, and limited skin phototoxicity than Photofrin, a current clinical standard. Methods: Imaging: IVIS/Spectrum: A noninvasive in vivo, continuous wave fluorescence imaging apparatus used to assess the localization and distribution of the PS at variable time points. In vivo efficacy studies using UMUC3 and T24 tumors in SCID mice with PS HPPH in combination with BCG. Results: Imaging: Tumor uptake in UMUC3 and T24 tumors using IVIS Imaging. PS HPPH showed high tumor uptake and significant difference in their pharmacokinetic profiles in UMUC3 and T24 tumors implanted in SCID mice: The SCID mice bearing either UMUC3 or T24 tumors (4-5 mm size) were injected with the PS HPPH. The tumored mice (3 mice/group) at a dose of 0.47 u-mol/kg) and imaged at variable time points. The uptake of tumor, liver, and skin was measured by IVIS system and interesting pharmacokinetic profiles of the PS were observed. The optimal tumors uptake in UMUC3 and T24 were at 24 hours and 8-12 hours, respectively. In vivo efficacy studies: PS (HPPH) in combination with BCG shows enhanced PDT efficacy CR (Cures) Day 30 = 14/22 = 63.6% and RG (Re-Growth) 6/22 = 36.4% in bladder tumors (UMUC3). To investigate the utility of combination treatment approach for treating bladder cancer, mice bearing UMUC3 tumors were injected intravenously with HPPH (0.47 u-mol/kg) and the tumors were exposed to laser light (135 J/cm2, 75 mW/cm2) at 24 h post-injection. One hour after the PDT treatment, BCG was injected (1-1.5 × 106 CFU), SQ weekly x 3 doses, and at day 30 the results are very encouraging. Conclusions: The HPPH showed higher in vivo uptake (determined by fluorescence) in UMUC3 and T24 bladder cancer tumors with significant differences in the two tumor types. The treatment of HPPH-PDT in combination with BCG using SCID mice bearing UMUC3 tumors showed enhanced long-term tumor cure. Before initiating this approach to human phase I clinical trial, further studies are under way. Source of funding: Roswell Park Alliance Foundation. Citation Format: Farukh Durrani, Ahmed Aly, Khurshid Guru, Ravindra Pandey. Photodynamic therapy in combination with immunotherapy enhances the long-term cure of bladder cancer in tumored mice [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2019 May 18-21; Denver, CO. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(15_Suppl):Abstract nr A02.

Conditional survival of patients with rectal cancer undergoing Watch and Wait: The risk of recurrence over time.

30 Background: Patients with rectal cancer and complete clinical response (cCR) after neoadjuvant chemoradiation (nCRT) have been offered non-operative management (W&amp;W). Risk factors for local regrowth (RG) include baseline cT and type of nCRT. However, the influence of risk factors for RG over time and the extent in time that patients need to be followed with the rectum in situ after a cCR are unknown. Objective: Analyze the risk of recurrence over time through conditional survival (cDFS/cLRFS) estimates for rectal cancer patients under W&amp;W. Methods: Retrospective analysis of all patients from the largest multicenter database of patients managed non-operatively (International Watch and Wait Database–IWWD). Only patients with cCR after nCRT and W&amp;W with a median of &gt;3 years of follow-up were included. cDFS was used to investigate the evolution of recurrence-odds, as patients remain disease-free after nCRT. 2-year cDFS was estimated at “x” years after nCRT based on the formula cDFS2=DFS(x+2)/DFS(x). Results: 768 patients treated between 1991-2015 were included. Using cDFSestimates, the probability of remaining disease-free for 2 additional years once cCR was achieved and sustained for 1, 3, and 5 years, were 85%, 97%, and 95%, respectively. These contrast with the actuarial DFS for similar intervals of 70%, 68% and 65% respectively. Baseline cT was associated with the risk of RG at 1 year after a cCR (cT2 aLRFS 89% vs. cT3 82%; p=0.004). However, after sustaining a cCR for 1 year, baseline cT becomes irrelevant at 2 years (cLRFS; 94% vs. 90%; |d| 0.14). Also, total dose of RT (≤50 vs &gt;50Gy) was associated with the risk of RG (aLRFS 76% vs 85%; p=0.03) at 1 year. Dose of RT becomes irrelevant (at 2 years; cLRFS 93% vs. 90%; |d| 0.10) once patients sustained a cCR for 1 year. Conclusions: Conditional survival estimates suggests that patients have significantly lower risks (≤5%) of developing late RG (at 5 years) after sustaining cCR for 3 years. A sustained cCR over time may be more relevant for long-term risk of RG than cT-stage or RT dose. The present data can have significant consequences for the recommendation of intensive surveillance after sustaining 3ys of cCR.

A bench scale study on the startup, performance and optimization of the biological degradation of obnoxious air containing trimethylamine

Trimethylamine [TMA] possess various toxic and contributes a hazardous impact on the living organism. The best treatment to eradicate TMA has to be explored and checked. The operation of a biotrickling filter seeded with Agromyces and Ochrobactrum sp. was optimized for degrading trimethylamine [TMA]. The filter bed was adjusted for continuous treating of TMA up to 20 days. The profile of TMA inlet concentration [IC] and air flow rate on the elimination capacity [EC] and removal efficiency [RE] was examined. A variation of RE [24.71–88.45%] in TMA degradation the filter bed was observed on different inlet loading rates [ILR]. The highest RE and microbial growth was recorded at a height of 45 cm. The output values were statistically deduced by carrying out an analysis of variance [ANOVA] to explicate the key and interacting properties. The biotrickling filter stability was also successfully determined with a temporary shutdown for a prolonged period of 15 days. The maximum EC attained for TMA was 29.28 g m-3 h-1 at inlet loading rate [ILR] of 57.6 g m-3 h-1.

Salvage surgery for local regrowths in Watch & Wait - Are we harming our patients by deferring the surgery?

BackgroundRectal cancer surgery conveys significant morbidity/mortality, long-term functional impairment and urinary & sexual dysfunction, especially if associated with neoadjuvant chemoradiotherapy (ChRT). Watch & Wait (W&W) is gaining momentum as an option for patients with clinical complete response (cCR) after ChRT. Approximately 30% will develop a local regrowth (RG) and need deferred surgery. Our study aimed to assess the short-term clinical outcomes after surgery for regrowths. Patients and methodsConsecutive rectal cancer patients from a tertiary institution who underwent neoadjuvant ChRT, between January 2013 and October 2018, were identified from a prospectively maintained database. Patients with RG under W&W surveillance were operated - regrowth deferred surgery (RDS) group - and compared to those with persistent disease after ChRT who did undergo surgery - non-deferred surgery (NDS) group. ResultsTotal of 124 patients received neoadjuvant treatment: 46 (37%) underwent surgery for persistent disease; 78 (63%) with cCR entered W&W. Twenty three developed RG and underwent surgery, while 55 remain under surveillance. RDS group had lower tumors than NDS group (2.3 cm ± 2 vs 4.5 cm ± 3, p = 0.002). All RG underwent minimally invasive surgery (MIS). Anastomotic leaks, 30-day morbidity, reintervention and readmission rates were similar. Pathology features and 3-year oncological outcomes were identical between groups. ConclusionPatients with initial cCR and local regrowth may be safely managed by deferred surgery. Short-term outcomes suggest equivalent results to patients with incomplete clinical response and immediate radical surgery. Delayed MIS appears to have no negative impact on oncological outcomes.

Is charcoal production in Brachystegia-Julbernardia woodlands of Zambia sustainable?

The bulk of the charcoal used in urban areas of Zambia is produced in old-growth (OG) woodlands that are receding further and further away in the hinterlands of towns. The present study was undertaken to assess whether the current charcoal production system in Brachystegia-Julbernardia (miombo) woodlands in Zambia is sustainable with respect to employment generation and biomass regeneration. Miombo woodlands are divided into dry (mean annual rainfall 700–1000 mm) and wet (>1000–1500 mm). Data from OG, re-growth (RG) and coupes were used in the assessment. Cord wood biomass of 56 t ha−1 in dry and 73 t ha−1 in wet miombo woodlands were significantly different resulting in differential charcoal yields of 4.04 and 6.64 t ha−1, respectively. Predicted cord wood accumulation in RG of 50 years old is estimated at 20 t ha−1 in dry miombo and 65 t ha−1 in wet miombo. At this rate of cord wood accumulation, charcoal production in dry miombo is considered unsustainable because it would require 2.3 ha of RG to produce the same amount of charcoal as in OG miombo. However, in spite of the higher production in wet miombo, it is estimated that cutting cycles of 50–55 years would be required to have charcoal yields that are similar to those currently observed in OG wet miombo woodlands. It is therefore recommended that strategies that contribute to the sustainability of charcoal production, employment generation and household energy security in the country be developed and implemented.

Effect of organic grass-clover silage on fiber digestion in dairy cows

There are differences in grass-clover proportions and chemical composition between herbage from primary growth (PG) and regrowth (RG) in grass-clover leys. Mixing silages made from PG and RG may provide a more optimal diet to dairy cows than when fed separately. We tested the hypotheses that increasing dietary proportions of grass-clover silage made from RG compared with PG would increase digestion rate of potentially degradable NDF (pdNDF), and increase ruminal accumulation of indigestible NDF (iNDF). Eight rumen cannulated Norwegian Red cows were used in two replicated 4×4 Latin squares with 21-day periods. Silages were prepared from PG and RG of an organically cultivated ley, where PG and RG silages were fed ad libitum in treatments with RG replacing PG in ratios of 0, 0.33, 0.67 and 1 on dry matter basis in addition to 8 kg concentrate. We evaluated the effect of the four diets with emphasis on rumen- and total tract fiber digestibility. Increasing RG proportions decreased silage intake by 7%. Omasal flow of pdNDF decreased, whereas iNDF flow increased with increasing RG proportions. Increasing RG proportions decreased rumen pool sizes of NDF and pdNDF, whereas pool sizes of iNDF and CP increased. Increasing RG proportions increased digestion rate of NDF, which resulted in greater total tract digestion of NDF. Pure PG diet had the highest calculated energy intake, but the improved rumen digestion of NDF by cows offered 0.33 and 0.67 of RG leveled out milk fat and protein yields among the three PG containing diets.

Effect of replacing organic grass-clover silage from primary growth with regrowth on N digestion in dairy cows

Clover proportions, and thereby chemical composition of herbage, differ between primary growth (PG) and regrowth (RG) in organic managed grass-clover fields. The characteristics of PG and RG silages suggest different supplementary feeding strategies to sustain an efficient milk production in dairy cows. Silage made of the RG generally offers more crude protein (CP) in the diet than silage made of the PG because of an increasing proportion of clover later in the season. Additionally, grass and clover have different amino acid (AA) profiles. His has been suggested to be the first limiting AA in grass silage, while Met has been suggested to be the primarily limiting AA in red clover silage. Eight rumen cannulated Norwegian Red cows were used in two replicated 4×4 Latin squares with 21-days periods. Organic PG and RG silages were fed ad libitum in four diets with RG replacing PG silage in ratios of 0, 0.33, 0.67 and 1 on dry matter (DM) basis. Changing RG silage proportions from 0 to 1 increased daily CP intake from 2.90 to 3.08kg and rumen NH3-concentrations from 4.9 to 8.4mmol/L, but did not promote a better protein supply. Neither total ruminal outflow of AA nor the AA profile in the small intestine differed between dietary treatments. Met and His were probably the most limiting AA for a higher milk production. Limitations by His may be more related to diets based on PG, while production by cows fed diets based on more RG herbage were more likely limited by Met.

Effect of replacing organic grass-clover silage from primary growth with regrowth on feed intake and milk yield of dairy cows

Under Norwegian conditions, diets based on primary growth (PG) silage typically increase milk yield compared to silage prepared from the regrowth (RG). Organic PG, dominated by immature grasses, is often high in energy and low in crude protein (CP), whereas the opposite is the case for organic RG harvests, dominated by clover. Here, we tested the hypotheses that increasing proportions of RG will reduce the total supply of metabolizable energy, but increase the CP intake, and that there is a dietary optimal mix of PG and RG to meet requirements for optimal milk production. Sixteen Norwegian Red cows were used in an experiment designed with four balanced 4 × 4 Latin squares with 21-day periods to evaluate the effect of incremental replacement of PG with RG on feed intake, nutrient digestion, and milk production. Silages were prepared from PG and RG of an organically managed grassland. Treatments comprised silages fed ad libitum with RG replacing PG in ratios of 0, 0.33, 0.67, and 1 on dry matter (DM) basis. Additionally, concentrate was offered with 8 kg for pluriparous and 7 kg for primiparous cows. The PG had higher content metabolizable energy (ME), potentially degradable neutral detergent fiber (NDF), and water-soluble carbohydrates, while RG contained more CP and indigestible NDF. The already mentioned characteristics led to higher intakes of DM, organic matter, NDF, and ME and lower intakes of CP and indigestible NDF with increasing proportions of PG in the diet. Milk yield tended to be higher when PG and RG were offered as a mixture than when fed alone. The milk fat concentration decreased linearly with increasing proportions of RG proportion, while protein concentration was unaffected by diet. This led to a similar production of energy-corrected milk among cows fed diets containing PG while cows fed pure RG diet produced 0.9 kg less daily. Silage energy concentration and energy intake influenced milk production more than CP supply.

The effect of harvesting strategy of grass silage on digestion and nutrient supply in dairy cows

This study examined the effects of primary growth (PG) and regrowth (RG) timothy-meadow fescue silages harvested at 2 stages of growth on feed intake, cell wall digestion and ruminal passage kinetics in lactating dairy cows. Four dairy cows equipped with rumen cannulas were used in a study designed as a 4 × 4 Latin square with 21-d periods. The experimental silages were offered ad libitum with 8 kg/d of concentrate. Ruminal digestion and passage kinetics were assessed by the rumen evacuation technique. Silages of PG were on average more digestible than RG silages. The concentration of neutral detergent fiber (NDF) and indigestible NDF (iNDF) increased and the concentration of digestible organic matter in dry matter (DM) of silages decreased with advancing maturity in PG and RG. Cows consumed more feed DM, energy, and protein and produced more milk when fed PG diets rather than RG diets. Delaying the harvest decreased DM intake and milk production in PG and RG. There were no differences between PG and RG in rumen pH, ammonia N, or total volatile fatty acid concentrations. The intake of N, omasal canal flow of total nonammonia N and microbial N, excretion of N in feces, and ruminal true digestibility of N were higher for PG than for RG diets. The efficiency of microbial N synthesis was not different between PG and RG. Intake and omasal canal flow of organic matter, NDF, and potentially digestible NDF (pdNDF) were higher in PG than in RG. Whole-diet digestibility of organic matter, NDF, or pdNDF in the rumen or in the total tract was not different between PG and RG despite the higher digestibility of PG silages measured in sheep. Rumen pool sizes of crude protein and iNDF were lower for PG diets, whereas the pool size of pdNDF was higher for PG diets than for RG diets. The rate of passage of iNDF was higher for PG diets than for RG diets, with no difference between them in rate of digestion or passage of pdNDF. The lower milk production in cows fed regrowth grass silages compared with primary growth silages could be attributed to the lower silage DM intake potential. Chemical composition of the silages, rumen fill, digestion and passage kinetics of NDF, or the ratio of protein to energy in absorbed nutrients could not explain the differences in DM intake between silages made from primary and regrowth grass.

Structural biomass partitioning in regrowth and undisturbed mesquite (Prosopis glandulosa): implications for bioenergy uses

AbstractHoney mesquite (Prosopis glandulosa Torr.) which grows on grasslands and rangelands in southwestern USA may have potential as a bioenergy feedstock because of existing standing biomass and regrowth potential. However, regrowth mesquite physiognomy is highly different from undisturbed mesquite physiognomy and little is known regarding growth rates and structural biomass allocation in regrowth mesquite. We compared canopy architecture, aboveground biomass and relative allocation of biomass components in regrowth (RG) trees of different known ages with undisturbed (UD) trees of similar canopy height to each RG age class. RG trees in most age classes (2–12 years old) had greater canopy area, leaf area, basal stem number, twig (&lt;0.5 cm diameter) mass and small stem (0.5–3 cm diameter) mass than UD trees of the same height. Large stem (&gt;3 cm diameter) mass was similar between RG and UD trees in all height classes. Ages of UD trees were determined after harvest and further comparisons were made between age, canopy structure and biomass in RG and UD trees. Relationships between age and total mass, age and height, and age and canopy area indicated a faster growth rate in RG than in UD trees. Large stem mass as a percentage of total tree mass accumulated more rapidly with age in RG than UD trees. Leaf area index and leaf : twig mass ratio were maintained near 1 in all RG and UD trees. Regrowth potential may be one of the most important features of mesquite in consideration as a bioenergy feedstock.

The effect of cutting time of grass silage in primary growth and regrowth and the interactions between silage quality and concentrate level on milk production of dairy cows

Two silages were prepared from the primary growth (PG) of timothy-meadow fescue sward at early (E) and late (L) stage of growth. The subsequent regrowth (RG) areas were further harvested at early (EE and LE) and late (EL and LL) stages of growth resulting in six silages in total. The silages were fed ad libitum to 24 lactating Finnish Ayrshire cows and supplemented with 8 or 12 kg concentrate per day in a cyclic change-over experiment with four 21-day periods and 6 × 2 factorial arrangement of treatments. The quality of silages varied markedly within and between the harvests although variation was greater within PG than RG. Postponing the harvest in PG decreased silage dry matter (DM) intake by 0.48 kg and energy corrected milk yield (ECM) by 0.61 per 10 g decrease in silage D-value (concentration of digestible organic matter in DM), while responses and the range between the diets were clearly smaller when RG silages were fed. On average, ECM yield was higher when PG rather than RG silages were fed. The mean response to increased concentrate DM intake was 0.62 kg ECM using diets based on PG. The response increased with increasing growth stage of grass being 0.34 and 1.01 kg ECM / kg additional concentrate DM for E and L, respectively. The difference was mainly mediated by the differences in substitution rates (reduction in silage DM intake per increase in concentrate DM intake, kg/kg), which were 0.71 and 0.22 for E and L, respectively. The ECM response to increased concentrate allowance was on average greater when RG rather than PG silages (0.92 vs. 0.62 kg/kg concentrate) were fed. Milk production of dairy cows reflected the intake of metabolizable energy and no differences in the utilization of it were found between diets based on silages harvested from PG and RG. However, intake of RG silages was slightly lower than that of comparable PG silage, but definite reasons for that could not be identified.

A tale of two views: Different perspectives on RE growth exist either side of the Atlantic

A tale of two views: Different perspectives on RE growth exist either side of the Atlantic

The effect of timothy silage on the bacterial population in rumen fluid of reindeer (Rangifer tarandus tarandus) from natural summer and winter pasture

The seasonal effect of first cut (FC) and regrowth (RG) timothy (Phleum pratense) silage on the rumen fluid bacterial population and the ability of this microbial ecosystem to digest cellulose was compared to that of reindeer from natural pasture (NP). FC with 27% leaves contained 30.4% dry matter (DM) cellulose and 6.2% DM water soluble carbohydrates (WSC), while RG with 89% leaves contained 18.4% DM cellulose and 30.0% DM WSC. The number of culturable anaerobic bacteria per ml rumen fluid on a habitat simulating medium (M8V) ranged between 1.1×108 and 95.0×108 in the reindeer (n=18) investigated, and no significant (P>0.05) differences were found between animals from NP and animals from the experimental groups in summer or winter. Carboxymethyl cellulose hydrolysing bacterial strains (n=138) isolated from the rumen fluid of the animals (n=18) using an acid-swollen cellulose medium were characterised as Butyrivibrio spp. (69.6%), Eubacterium spp. (1.4%), Clostridium sp. (0.7%) and unknowns (28.3%). Cellulolytic strains of B. fibrisolvens were isolated from only one of the calves, which had been fed RG in summer. The rumen bacterial composition in reindeer on NP resembled that of the experimental groups. In vitro digestibility trials demonstrates that the ability of the rumen microbiota to digest cellulose is generally reduced in reindeer fed silage in summer compared to winter. Ruminal malfunction occurred in some of the animals, but no correlation between the composition of the bacterial population in the fluid fraction of the rumen and the ability of this microbiota to ferment cellulose was found.

‘TifEagle’ Bermudagrass Response to Growth Factors and Mowing Height when Grown at Various Hours of Sunlight

Application of growth promoters or inhibitors and mowing height adjustment are potential means of improving the growth and performance of TifEagle bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy] in a reduced light environment (RLE). A study was conducted in June to August 2001 and 2002 to examine the effects of growth factors and two mowing heights on TifEagle bermudagrass when grown at various hours of sunlight. Shade cloth (92%) was used at different intervals to obtain three sunlight hours, 12 h (0800–2000 h), 8 h (1000–1800 h), and 4 h (1200–1600 h), with an average 2‐yr daily light integral (DLI) of 41.1, 35.5, and 22.1 mol m−2 d−1, respectively. Sunlight hours were split by growth factor applications and mowing height. Growth factors included trinexapac‐ethyl [TE; 4‐(cyclopropyl‐alpha‐hydroxymethylene)‐3,5‐dioxo‐cyclohexanecarboxylic acid ethyl ester] at 0.0393 kg a.i. ha−1 every 3 wk, gibberellic acid (GA) at 0.059 kg Gibberellin A3 (GA3) ha−1 every 2 wk, additional nitrogen (+N) application of 24.5 kg N ha−1 every 2 wk, and an untreated check. Turf was mowed at 3.2 or 4.7 mm daily. Acceptable turf quality (TQ) followed all growth factor treatments receiving the 12 and 8 h of sunlight, except GA. For the 4‐h sunlight treatments, only plots treated with TE and mowed at 4.7 mm resulted in acceptable TQ. The +N applications increased percentage lateral regrowth (RG) of TifEagle bermudagrass by 7 to 10% compared with other growth factors. Across all sunlight treatments, TE increased total shoot chlorophyll by as much as 19 and 42% compared with untreated, +N, and GA‐applied plots. The 3.2‐mm mowing height increased total nonstructural carbohydrates (TNC) by 19% compared with TifEagle mowed at 4.7 mm. Growth factors, including TE, +N, or GA, did not improve TNC concentration. In a RLE, methods of improving the growth and performance of TifEagle bermudagrass include TE applications and raising the height of cut to 4.7 mm. Overall, the growth and performance of TifEagle bermudagrass reduced greatly in the 4‐h sunlight treatments compared with 12‐ and 8‐h sunlight treatments.

Quantifying a Daily Light Integral Requirement of a ‘TifEagle’ Bermudagrass Golf Green

‘TifEagle’ bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy] is a fine textured hybrid bermudagrass used for golf course putting greens in the subtropical and tropical regions of the world. The growth and performance of TifEagle and other bermudagrass often decline in reduced light environments (RLEs). This study quantified a daily light integral (DLI; mol m−2 d−1) required to maintain commercially acceptable TifEagle bermudagrass maintained under golf green conditions. Three levels of shade, none, low, and high (0, 41, and 92%), were applied to mature TifEagle bermudagrass during morning (sunrise to 1100 h) and afternoon (1500 h to sunset) hours, allowing full irradiance from 1100 to 1500 h to mimic a golf green situation where trees or structures are adjacent to, but rarely directly overhead. The study was performed for 8 wk in June to August 2001 and 2002. An average minimal DLI of 32.6 mol m−2 d−1 was needed to maintain commercially acceptable TifEagle turf quality (TQ ≥ 7). Other plant responses measured included percentage lateral regrowth (RG), total shoot chlorophyll, and total nonstructural carbohydrates (TNC). These responses declined significantly when the DLI ≤ 32.6 mol m−2 d−1 Differences in diurnal shade exposure occurred. High afternoon shade reduced TifEagle bermudagrass TQ, percentage lateral RG, shoot chlorophyll, and TNC by 3.0 rating units and 17, 39, and 27%, respectively, compared with no afternoon shade (NSA). High morning shade reduced TQ, percentage lateral RG, and shoot chlorophyll by 1.5 rating units and 11 and 16%, respectively, compared with no morning shade (NSM). Overall, afternoon shade applications were more detrimental to TifEagle bermudagrass growth and performance compared with morning shade.