Similar Growth Stages Research Articles

The first deep-snouted tyrannosaur from Upper Cretaceous Ganzhou City of southeastern China

Tyrannosaurids were the most derived group of Tyrannosauroidea and are characterized by having two body plans: gracile, long-snouted and robust, deep-snouted skulls. Both groups lived sympatrically in central Asia. Here, we report a new deep-snouted tyrannosaurid, Asiatyrannus xui gen. et sp. nov., from the Upper Cretaceous of Ganzhou City, southeastern China, which has produced the large-bodied and long-snouted Qianzhousaurus. Based on histological analysis, the holotype of Asiatyrannus xui is not a somatically mature adult, but it already passed through the most rapid growth stages. Asiatyrannus is a small to medium-sized tyrannosaurine, with a skull length of 47.5 cm and an estimated total body length of 3.5–4 m; or around half the size of Qianzhousaurus and other large-bodied tyrannosaurines in similar growth stages. Asiatyrannus and Qianzhousaurus are sympatric tyrannosaurid genera in the Maastrichtian of southeastern China. Asiatyrannus differs from Qianzhousaurus in that it has a proportionally deeper snout, longer premaxilla, deeper maxilla, and deeper dentary, and the cornual process of the lacrimal is inflated without developing a discrete horn. The different skull proportions and body sizes suggest that Asiatyrannus and Qianzhousaurus likely had different feeding strategies and occupied different ecological niches.

Modified laminar bone did not stop sauropods from achieving large body sizes

ABSTRACT An almost complete dinosaur femur found in the Baynshire Formation (late Cenomanian to Santonian; Mongolia) in 1963 during the Polish–Mongolian Paleontological Expeditions is described here for the first time. The morphology of the femur and bone histology suggest that the specimen was a representative of the Titanosauriformes, the predominant sauropod clade during the Cretaceous. Bone tissue exclusive to this clade, modified laminar bone that indicates a reduced growth rate, is identified in the thin sections taken from the femur. Based on its bone histology, the already ca. 20-meter-long specimen appears to be a subadult. This specimen achieved a significantly larger size compared with other Titanosauriformes with modified lamellar bone at a similar growth stage.

Performance of dairy cows offered either zero-grazed grass or grass silage prepared from the same sward

Daily harvesting of fresh grass for housed livestock when its nutritive value is high (Zero-grazing) is a labour-intensive process which requires a consistent supply of grass at the optimum growth stage. An alternative approach which may save on labour and require less time spent on grassland management each day, involves harvesting and ensiling herbage on a number of occasions (every 4 weeks approximately) during the growing season when it is at the same nutritive value as herbage used for zero-grazing. This study examined the impact of these two approaches to dairy cow performance. Thirty-six mid-lactation Holstein-Friesian dairy cows were offered either zero-grazed fresh grass (ZG), or grass silage (SIL) prepared from the same sward harvested at a similar growth stage, over a single season. Fresh grass was harvested daily and offered to ZG cows for a 12-week period. During this period, the same sward was harvested once weekly and ensiled in round bales. Following a five-week ensilage period, the silage was offered to cows on SIL for a 12-week period. All cows were also offered 8.0 kg concentrate per day. Zero-grazed grass and grass silage had a mean metabolisable energy content of 11.0 and 11.3 MJ/kg DM, respectively. Mean forage DM intake (DMI) and total DMI were greater for cows on ZG (P < 0.001) compared to SIL, with intakes during weeks 8–12 of the experiment lower with SIL compared to ZG (P < 0.001). Cows on ZG had a higher milk yield, milk protein concentration, milk fat plus protein yield and energy-corrected milk (ECM) yield (P < 0.001) than cows on SIL. With the exception of milk yield (where the difference was primarily observed during weeks 8–12 of lactation), these differences were observed most weeks during the study period. Milk fat concentration was unaffected by treatment (P > 0.05). Milk of cows on ZG had higher concentrations of total monounsaturated fatty acids (P < 0.001), total polyunsaturated fatty acids (PUFAs, P < 0.001) but lower concentrations of saturated fatty acids (SFAs, P < 0.001) compared to cows on SIL. Diet had no effect on cow BW or condition score. This study has shown that when harvested from the same sward, milk yield and ECM yield were improved when cows were offered zero-grazed grass compared to grass silage. This difference in performance was likely due to the lower forage intake observed with the grass silage-based diet.

Model based predictive control strategy for water saving drip irrigation

Traditional irrigation control systems is characterized with inefficient management of water and often results in low water productivity index and reduced cultivation yield. In addition, insufficient water supply and high rate of water loss due to evapotranspiration increases plant stress which often affects its growth and development. Therefore, to address this issues, this paper is aimed at developing a model predictive control (MPC) strategy for water saving drip irrigation experiment that will regulate the soil moisture content within the desired field capacity and above the wilting point, while scheduling irrigation to replace the loss of water from soil and plant due to evapotranspiration in the greenhouse environment. The controller design involves a data driven predictive model identified and integrated with the MPC designer in MATLAB and thereafter exported in Simulink for simulation. The generate controller code was modified and deployed on a Raspberry Pi 4 controller to generate a pulse width modulated signal to drive the pump for the control water mixed with fertilizer. To achieve enhancement of controller an Internet of Things (IoT) integration was used for easy soil, weather, and plant monitoring which are used to update the MPC model for the irrigation control. The performance of the proposed MPC controller deployed drip irrigated Greenhouse(GH1) is benchmarked against an existing automatic evapotranspiration (ETo) model based controller in Greenhouse(GH2), with each greenhouse containing 80 poly bags of Cantaloupe plant with similar growth stage. The results obtained shows that, the proposed MPC-based irrigation system has higher water productivity index of 36.8 g/liters, good quality of fruit with average sweetness level of 13.5 Brix compared to automatic ETo-based irrigation system with 25.6 g/liters and 10.5 Brix, respectively. However, the total mass of harvested fruit for ETo-based irrigation system is higher than MPC-based irrigation system by 21.7%. The performance of the proposed MPC controller was achieved through the integration of event based scheduling with IoT monitoring as well as inclusion of evapotranspiration effect in the plant dynamics.

Retrospective stable isotopes of vertebrae reveal sexual ontogenetic patterns and trophic ecology in oceanic whitetip shark, Carcharhinus longimanus.

There is a common phenomenon in nature whereby some animals have differences in their ontogenetic changes in dietary preferences between sexes, especially apex predators. These reflect changes in the needs of development during their lifetimes. Apex predators potentially have diverse dietary niches and a large impact on the trophic dynamics within ecosystems. However, the difference in life history between males and females often leads to increased difficulty in management and conservation. In this study, 25 oceanic whitetip sharks, Carcharhinus longimanus, were collected from the central and eastern tropical Pacific. Retrospective stable isotope analysis of vertebrae was used to evaluate the potential ontogenetic differences in feeding habits and niche width between sexes. Results showed that C. longimanus had a wide range of δ13C values (−18.1 to −12.3‰) and δ15N values (8.9–14.8‰). However, males and females had similar trophic positions with large niche overlap at similar growth stages. Both sexes had increasing δ13C values but relatively constant δ15N values along the vertebrae. These results indicated that male and female C. longimanus may share similar feeding strategies and movement patterns. The results presented in this study enhance our understanding of sexual ontogenetic patterns and ecological role of C. longimanus and highlighted the applicability of vertebrae for characterizing shark life‐history traits.

Subterranean morphology modulates the degree of mycoheterotrophy in a green orchid Calypso bulbosa exploiting wood‐decaying fungi

Abstract Many vascular plants and aquatic organisms are not strictly autotrophic or heterotrophic but rather mixotrophic. Mixotrophy is a widespread nutritional strategy, merging autotrophy and heterotrophy to acquire organic carbon (C). Because all orchids are mycoheterotrophic during the early stages, many species are also predisposed to mycoheterotrophic nutrition during the mature stage. Consequently, many green orchids adopt partially mycoheterotrophy, a kind of mixotrophic strategy, obtaining carbon through autotrophy and mycoheterotrophy. However, the proportions of fungal‐derived carbon reported for these mixotrophic orchids show considerable variation, even within species under similar light conditions and at similar growth stages. The factors promoting such variation remain to be fully elucidated. We investigated the nutritional mode of a green orchid Calypso bulbosa to determine whether coralloid rhizomes, which are often found in fully mycoheterotrophic orchids, affect the degree of mycoheterotrophy. To this end, we performed molecular barcoding and 13C and 15N analyses to identify the mycorrhizal partners and fungal dependency of C. bulbosa specimens with and without coralloid rhizomes. We found that C. bulbosa individuals were consistently colonized by an OTU of the wood‐decaying fungal genus Protomerulius (Auriculariales), regardless of the presence of rhizomes. Furthermore, although both types of C. bulbosa specimens are partially mycoheterotrophic, as indicated by their higher 13C and 15N abundances, those with coralloid rhizomes exhibited a higher degree of mycoheterotrophy. Our results indicate that partial mycoheterotrophy in C. bulbosa is a flexible mechanism driven by subterranean morphology. Although mixotrophy has evolved repeatedly in vascular plants and aquatic organisms, their trophic plasticity remains largely unexplored. Here we propose a novel mechanism modulating the degree of mycoheterotrophy in green orchids, providing a new perspective on the ecological plasticity of nutritional mode in mixotrophic organisms. A free Plain Language Summary can be found within the Supporting Information of this article.

Integrated technology roadmapping in startups: a case study of an AgTech in the Cachaça industry

Companies develop strategies to describe where they want to go and how they will reach their destination. Business strategies are useful but may not be sufficiently detailed for areas of high importance, such as technology and innovation. In this paper we examined the effort of building a technology roadmap with an early growth stage company located in the state of São Paulo, Brazil. Roadmaps are easy to design yet flexible tools that can allow decision makers to explore a myriad of possible strategies. However, the challenges ahead for new companies facing uncertain growth scenarios demand that framework conditions be adequately addressed, and that innovation culture and technology management tools are integrated with the technology roadmapping strategy. Based on the empirical evidence collected from the startup studied, along with the literature and interviews with key stakeholders, this paper developed a pathway to support technology and innovation plans for startups going through similar growth stages and provides directions for future research in the area, given the scarcity of evidence available of new high-tech companies' efforts in planning and developing new products

Screening for heat-resistant reference yeast isolate in orange juice

This study details a screening process for yeast species that may be used as reference microorganisms for mild thermal processing of orange juice. In the initial step, 17 different strains of spoilage yeasts with similar initial populations (6.0–7.0 log CFU/mL) and growth stage (middle stationary phase) were subjected to equal heating process (55 °C, 5 min) in Yeast Peptone Glucose Broth (pH 6.06). The change in populations observed ranged from 3.33 log CFU/mL (Pichia fermentans BFE-38) to 6.53 log CFU/mL (Torulaspora delbrueckii BFE-37). In the second step of the screening, 6 of the most resistant strains were further challenged in an orange juice suspending medium (pH 3.88, 10.02 °Brix, 0.82% citric acid) at different heating temperatures (50, 53, 55, 57, and 60 °C). The decimal reduction times (DT values) and thermal resistant constants (z values) were determined. Results showed that all tested yeasts exhibited first-order, log-linear inactivation behavior (R2 0.90–0.99). As expected, significant (P < 0.05) reduction in the DT values were observed with increasing temperature. P. fermentans BFE-38 exhibited the greatest Dvalues at 50–55 °C. However, the test isolate with the greatest z-value was found to be P. anomala (BIOTECH 2205).

Crop Type Classification Using Fusion of Sentinel-1 and Sentinel-2 Data: Assessing the Impact of Feature Selection, Optical Data Availability, and Parcel Sizes on the Accuracies

Crop type classification using Earth Observation (EO) data is challenging, particularly for crop types with similar phenological growth stages. In this regard, the synergy of optical and Synthetic-Aperture Radar (SAR) data enables a broad representation of biophysical and structural information on target objects, enhancing crop type mapping. However, the fusion of multi-sensor dense time-series data often comes with the challenge of high dimensional feature space. In this study, we (1) evaluate how the usage of only optical, only SAR, and their fusion affect the classification accuracy; (2) identify the combination of which time-steps and feature-sets lead to peak accuracy; (3) analyze misclassifications based on the parcel size, optical data availability, and crops’ temporal profiles. Two fusion approaches were considered and compared in this study: feature stacking and decision fusion. To distinguish the most relevant feature subsets time- and variable-wise, grouped forward feature selection (gFFS) was used. gFFS allows focusing analysis and interpretation on feature sets of interest like spectral bands, vegetation indices (VIs), or data sensing time rather than on single features. This feature selection strategy leads to better interpretability of results while substantially reducing computational expenses. The results showed that, in contrast to most other studies, SAR datasets outperform optical datasets. Similar to most other studies, the optical-SAR combination outperformed single sensor predictions. No significant difference was recorded between feature stacking and decision fusion. Random Forest (RF) appears to be robust to high feature space dimensionality. The feature selection did not improve the accuracies even for the optical-SAR feature stack with 320 features. Nevertheless, the combination of RF feature importance and time- and variable-wise gFFS rankings in one visualization enhances interpretability and understanding of the features’ relevance for specific classification tasks. For example, by enabling the identification of features that have high RF feature importance values but are, in their information content, correlated with other features. This study contributes to the growing domain of interpretable machine learning.

Laboratory Assessment of Host Plant Selection of the Brown Marmorated Stink Bug (&amp;lt;i&amp;gt;Halyomorpha halys&amp;lt;/i&amp;gt;)

The behavioral response of brown marmorated stink bug, <i>Halyomorpha halys</i> (Hemiptera: Pentatomidae), to various phenological growth stages (leaf, flower and pod/seed/kernel) of six host plants (soybean, corn, sunflower, Early Scarlet and Mississippi Silver cowpeas, and princess tree leaf) was investigated in a Dual Choice Arena Test (DCAT) and Multiple Choice Arena Test (MCAT). In DCAT, each experiment consisted of one of the growth stages of each plant with princess tree leaf as the standard. In MCAT, two experiments were conducted using: (1) similar growth stages from the different plants and (2) different growth stages from the same plant. <i>Halyomorpha halys</i> distribution was observed at time intervals up to 24 hours after insects were released. Results from MCAT and Preference Index (PI) from the DCAT indicated that more <i>H. halys</i> were recorded on princess tree leaves. Mississippi Silver (PI=1.59±0.05) and Early Scarlet (PI=1.49±0.08) flowers were preferred over princess tree leaves and other flowers (PI≤1). Sunflower seed was the least preferred (PI=0.43±0.18) among similar growth stages. Overall, the reproductive stages were preferred over the vegetative stage. Our findings can be useful in developing management programs such as trap cropping for this pest.

Phenological growth stages of the cashew tree (Anacardium occidentale L.) according to the extended BBCH scale

AbstractThe cashew is an important nut crop cultivated in the tropical regions. It is known for its economic and nutritional value. Phenology is the study of seasonal timing of recurring events in the annual growth cycle. A generic scale such as the Biologische Bundesantalt, Bundessortenamt and Chemische Industrie (BBCH) scale defines developmentally similar growth stages of different crops and within it, more specific scales for individual species can be developed. In the current study, detailed descriptions and codes are proposed for the growth stages of cashew using a modified three‐digit scale of BBCH. Seven principal growth stages viz. bud, leaf and shoot development, inflorescence emergence, flowering, fruit development, and fruit maturity were described. A total of thirty‐seven secondary growth stages were identified and described within the seven principal growth stages. Due to the importance of phenological growth stages in crop management and crop improvement, the proposed phenological scale is expected to facilitate better adoption of cultural practices, efficient germplasm characterisation and help in studying the impact of climate change on cashew production.

Nasal function before and after rapid maxillary expansion in children: A randomized, prospective, controlled study

ObjectivesChildren can well detect and respond to odours in order to have information about food and environment.Rapid Maxillary Expansion seems to improve dental and skeletal crossbite and increase nasal patency correcting oral respiration in children. A previous pilot study suggested that Rapid Maxillary Expansion may lead to improved N-Butanol olfactory thresholds, and peak nasal inspiratory flow values (PNIF). The aim of the present study was to prospectively evaluate olfactory threshold, nasal flows and nasal resistances in children aged from 6 to 11 years before and after Rapid Maxillary Expansion, comparing treated children with a control group of similar age, growth stage (prepubertal) and transversal skeletal deficiency. MethodsN-butanol olfactory thresholds, anterior active rhinomanometry (AAR) and PNIF were measured in 11 children (6–11 years) before (T0), immediately and 6 months after Rapid Maxillary Expansion application (T1 and T2 respectively), and in a control group of 11 children (6–11 years) whose members remained under observation for the period of the study. ResultsConsidering the study group, PNIF values improved at T1 respect to the T0 values (p = 0.003), while T2 values were significantly higher than T0 ones (p = 0.0002). N-Butanol Olfactory Threshold significantly improved at each control (p = 0.01, p = 0,01 and p = 0.0003, for T1 vs T0, T2 vs T1, T2 vs T0 respectively). No differences on AAR values were found during the six months follow-up in this group.Considering the control group, no significant differences were found for any of the considered variables during the time of the study.Comparing the two groups, there was a significant increase of PNIF values in the study group compared to the control group (p = 0.003) at T1, which was even more evident six months after Rapid Maxillary Expansion (p = 0.0005). This improvement was not shown by AAR values. N-Butanol Olfactory Threshold showed a significant improvement at T2 respect to T1 (p = 0.002) and T0 (p = 0.0005). ConclusionRapid Maxillary Expansion seems to significantly improve the respiratory capacity of treated patients, at least in terms of PNIF, and their olfactory function, measured by N-Butanol Olfactory Threshold Test. Further studies should be performed to evaluate if also changes in nasal resistances, measured by AAR, could occur, maybe considering a larger group of subjects and possibly using 4-phase rhinomanometry in order to evaluate the effective resistances during the entire breath.

Prevalence of Botrytis cinerea at different phenological stages of table grapes grown in the northern region of South Africa

Abstract Botrytis cinerea, is one of the major causal agents of postharvest decay in table grapes, contributing to 20% losses world-wide. The aim of this study was to determine the prevalence of B. cinerea at different phenological growth stage (full bloom, pea size and fully mature berries) and the impact of agro-climatic sites on pathogen incidence. Droplet digital polymerase chain reaction (ddPCR) was used simultaneously with culture based methods to detect and quantify B. cinerea. Botrytis cinerea was detected at different phenological stages on asymptomatic grape samples. Prevalence and level of B. cinerea differed between phenological stages and sites. Full bloom stage of site B showed the highest prevalence of B. cinerea (82.9%) compared to site A (33.3%). For the latter phenological stages (pea size and mature stage), site A had the highest prevalence (100% for both), compared to 35.2% and 44.4% observed at site B, respectively. Furthermore, the B. cinerea concentration varied between stages within the two sites. The concentration of B. cinerea at site A showed a threefold increase from pea size (2.67 copies μL−1 of DNA) to mature berry stage (9.16 copies μL−1 of DNA), compared with the decline noted for similar growth stages at site B. Botrytis cinerea inoculum build up on asymptomatic grapes could be effectively monitored as the berry develops at critical phenological stages. Preharvest monitoring of the pathogen can help growers improve well-established cultural and management practices, hence limit the risk of postharvest decay.

Bases nutricionales para la alimentación proteica del cerdo Ibérico puro

Along this review we describe the results from a series of experiments performed to assess the utilization of dietary protein by the Iberian pig throughout different stages of its productive cycle. Nutritional dose-response studies involving several isoenergetic treatments differing in protein concentration -all with similar amino acid profile following the ideal protein concept- along with comparative growth and metabolic studies with conventional breeds have been performed. Our observations reveal that the capacity of this breed for protein accretion is rather limited compared to that of conventional breeds at similar stages of growth, and suggest the need for reducing the concentration of protein in the diet of the Iberian pig to comply with its metabolic profile. Basic comparative studies have brought to light information to help us explaining some of the metabolic peculiarities of this autochthonous breed of pigs, like the low capacity to accrete protein and lean tissue. We summarise all the information gathered in several experiments and provide recommendations on the concentration and composition of dietary protein in the diet for purebred animals during different phases of growth. Adequate nutritional management, particularly dietary protein provision, improves the efficiency of utilization of dietary protein and results in relevant economic, environmental and animal welfare benefits.

Constitutive Model of Rock Uniaxial Damage Based on Rock Strength Statistics

Based on the assumption that rock strength follows the log normal distribution statistically, this paper establishes a damage constitutive model of rock under uniaxial stress conditions in combination with the Mohr–Coulomb strength criterion and damage mechanical theory. Experiments were carried out to investigate the damage evolution process of rock material, which can be categorized into nondamaging, accelerated growth, constant‐speed, similar growth, and speed‐reducing growth stages. The evolution process had a good corresponding relationship with the rock stress‐strain curves. Based on the statistical damage constitutive model proposed in this paper, a numerical fitting analysis was conducted on the uniaxial compression testing data of laboratory sand rock and on experimental data from other literature, in order to validate the rationality of the constitutive equation and the determination of its parameters and to analyze the effect of internal friction variables on damage variables and compression strength. The research outcomes presented in this paper can provide useful reference for the theory of rock mechanics and for rock engineering.

Propelled abrasive grit applications for weed management in transitional corn grain production

AbstractWeed control is challenging to farmers who are transitioning from production systems that use synthetic herbicides to organic systems. A 2-year field study examined air-propelled corncob grit abrasion for in-row weed control efficacy and effect on corn yield. Grit was applied based on corn vegetative developmental stages with one (V1, V3 or V5), two (V1 + V3, V1 + V5, or V3 + V5), or three (V1 + V3 + V5) applications. Flame-weeding or cultivation was used after the V5 application for between-row weed control. Grit applications decreased in-row weed densities by about 60% (α = 0.05) and biomass up to 95% (α = 0.001). Between-row treatments provided similar control, and reduced weed biomass by 55% in 2013 (α = 0.01) and 86% (α = 0.001) in 2014. In-row grit treatments increased corn yield up to 44%, and yield was more influenced by in-row weeds than between row weeds. These results indicate that abrasive corncob grit for in-row weed control, supplemented with cultivation or flaming, can reduce weed biomass substantially and help maintain corn yield. However, timing and frequency of grit application need further refinement based on weed growth as influenced by climate, as treatments at similar corn growth stages did not consistently provide adequate weed control between years.

Relationship between spring triticale physiological traits and productivity changes as affected by different N rates

ABSTRACTThere is still a lack of knowledge about the physiological traits of spring triticale (x Triticosecale Wittm.) and their relationship with grain yield and protein content under the conditions of the environmental Zone Nemoral 2. The objective of this study was to determine the relationships among the physiological indices, grain yield and protein content as affected by nitrogen (N) rates. The correlation among leaf area index (LAI), chlorophyll index (SPAD), canopy greenness index (CGI), leaf area duration (LAD) and grain yield as well as direct and indirect effects of those traits on the yield were investigated using a path analysis. Grain yield, protein content and physiological indices were significantly (P ≤ .01) affected by N fertilization. N90 level was the best compromise for the yield and physiological indices. The interaction of all physiological indices influenced the grain yield by 27–39%, protein by 42–44%. SPAD and LAI had greater influence on grain yield and grain protein than CGI and LAD. SPAD had positive direct dominant (the highest) effect on the yield only at BBCH 59 and BBCH 69 (50% of the tested cases). LAI was responsible for 19–39% of the correlation between yield and physiological indices. The physiological indices can be used for spring triticale growth modelling and agronomic management for improved productivity and grain quality. SPAD and LAI values, established at BBCH 45–69, can be used for grain yield prediction and those estimated at BBCH 69 can be used for grain protein prediction.Abbreviations BBCH: Biologische Bundesantalt, Bundessortenamt und Chemische Industrie (decimal system for a uniform coding of phenologically similar growth stages of all mono- and dicotyledonous plant species); CGI: canopy greenness index; GS: growth stage; LAD: leaf area duration; LAI: leaf area index; SPAD: chlorophyll index (soil plant analysis development)

Supplement understanding of the relative importance of biophysical factors in determination of photosynthetic capacity and photosynthetic productivity in rice ecosystems

Extensive variation in gross primary production (GPP) among growing seasons in rice ecosystems, which has previously been reported, may be caused by a number of biophysical factors. Two field-based studies, one on Oryza sativa L. cv. Odae in the Haean Basin and the other on O. sativa L. cv. Unkwang in Gwangju, South Korea, were conducted to evaluate physiological regulators of the ecosystem. A literature survey across climatic zones was additionally undertaken to unravel the roles of relevant climatic factors. The results from the two field studies showed that the correlation between the fraction of canopy light interception (fPAR) and leaf area index (LAI) across all data sets exhibited a common trajectory. Analogous values of canopy light use efficiency (LUEc) at similar growth stages of the two rice crops, but, clearly varietal and nutritional differences in LAI development were present, which implies that temporal differences in carbon gain capacity are related to modifications in LAI, thereby influencing fPAR. The literature survey revealed that most variations in growing season GPP can be explained by changes in daily solar radiation (SR) which is negatively correlated to the proportion of rainy days; this is supported by the two field studies. In the context of temperature warming, a reduction in SR noticeably exacerbated impacts on photosynthetic productivity. Moreover, global values of maximum carbon gain capacity over the growing season (GPPday-max) in field-cultivated rice were significantly affected by SR. We suggest that: 1) temporal differences in carbon gain capacity and variations in GPPday-max are jointly driven by LAI development, which varies according to nutrient availability and rice genotypes, and SR, especially at the reproductive stage; 2) although photosynthetic productivity of rice ecosystems is vulnerable to temperature increasing and prolonged growth duration contributes to larger photosynthetic productivity, its fluctuations across growing seasons are profoundly mediated by SR, which statistically correlates with the amount of precipitation; and 3) the important regulating implication of SR changes is attributed to the structure rather than physiology dependent light sensitivity of canopy photosynthesis at the reproductive stage. Further researches regarding interactions among climate change, phenology and canopy carbon dynamics are discussed.

Effect of purple prairie clover (Dalea purpurea Vent.) hay and its condensed tannins on growth performance, wool growth, nutrient digestibility, blood metabolites and ruminal fermentation in lambs fed total mixed rations

This study evaluated the effects of purple prairie clover (PPC, Dalea purpurea Vent.) hay and its condensed tannins (CT) on feed intake, growth performance, wool growth, nutrient digestibility, blood metabolites and rumen fermentation in lambs fed diets containing PPC and alfalfa hay. Alfalfa and PPC were harvested at similar growth stage, sun-cured to <12% moisture, and stored in a shed for 120 d. Thirty six individually fed lambs were randomly allocated into three groups and fed total mixed ration containing 40% (dry matter (DM) basis) of a pelleted barley grain based concentrate and 60% of alfalfa hay (AH), or 60% PPC hay (PH) or PH supplemented with polyethylene glycol (PH-p) for 77 d. Lambs were fed once daily and weighed bi-weekly. Faeces samples were collected in the 5th wk for 5 d to determine nutrients digestibility using acid insoluble ash as a marker. Lambs were slaughtered at the end of experiment to evaluate the carcass characteristics. Wool yield and quality were measured using a 10cm dye band applied on d 0 and harvested on d 75. Blood samples were collected to analyze serum metabolites and antioxidant enzymes, and rumen fluid was sampled to analyze rumen fermentation products. Lambs fed PH had lower (P<0.01) DM intake than AH or PH-p. Growth performance, wool growth parameters and carcass characteristics did not differ among diets. Lambs fed PH-p had greater (P<0.05–0.001) DM, organic matter (OM), crude protein (CP), neutral detergent fibre (aNDF) and acid detergent fibre (ADF) digestibility than those fed AH, and greater (P<0.05–0.001) CP, aNDF and ADF digestibility than those fed PH diet. Lambs fed PH exhibited greater apparent total tract digestibility of DM (P<0.05) and OM (P<0.05) and tended (P=0.059) to have greater CP digestibility compared to those fed AH. Lambs consuming PH diet had lower (P<0.05) blood urea nitrogen and creatinine than AH and lower (P<0.05) blood glucose and urea than PH-p, but greater (P<0.01) total antioxidant capacity and catalase activity than AH diet. Lambs fed PPC CT had lower (P<0.05) concentrations of ammonia, total VFA, propionate, iso-butyrate, iso-valerate and protozoa. It was concluded that PPC hay had greater nutritive value to alfalfa hay owing to its greater DM, OM and protein digestibility, but did not improve lamb growth.

Effects of breed, sex, and concentrate supplementation on digestibility, enteric methane emissions, and nitrogen utilization efficiency in growing lambs offered fresh grass.

Forty-eight lowland lambs were used in a completely randomized design (23-d period) with a factorial arrangement of treatments: 2 breeds (Highlander vs. Texel) × 3 sexes (female vs. intact male vs. wether) × 2 diets (fresh grass vs. fresh grass plus 0.5 kg/d pelleted concentrate). Animals ( = 48) were approximately 5 mo old and 36 ± 5.0 kg BW at the commencement of the study with 4 lambs for each breed-sex-diet combination. Fresh grass was harvested daily from the first regrowth of perennial ryegrass sward and offered ad libitum with a similar growth stage throughout the experiment. The animals were individually housed in pens and fed experimental diets for 19 d before being transferred to individual calorimeter chambers for a further 4 d with feed intake, fecal and urine outputs, and methane (CH) emissions measured. Lambs offered 0.5 kg/d concentrate had greater DM and energy (i.e., GE, DE and ME) intake, BW, and CH production (g/d) and greater N intake, fecal and manure N outputs, and fecal N per N intake than those given only fresh grass ( < 0.05). However, diets had no effect on CH emission rates (i.e., CH/DMI [ = 0.408] and CH energy/GE intake [ = 0.821]). Texels produced more CH/DMI (g/kg) than Highlanders ( = 0.044), and sex had no effect on CH/DMI (g/kg; = 0.101). Neither breed nor sex had an effect on N utilization efficiency ( > 0.05). The results reflected that high-quality forages may play a role similar to concentrate in mitigation of enteric CH emissions. The effects of sex and breed on rumen function require further investigation to understand relationships with CH emissions and N excretion in sheep.