Noy-Meir's simple but insightful model of grazing-system dynamics was used to draw broader inferences from empirical data generated by a 17-year field trial with beef cattle grazing a Mediterranean grassland in northern Israel. After calibration of its parameters against the field results, the model predictions were tested against an independent set of data obtained from the study site; they were within acceptable deviations from the inherently noisy field data. The calibrated model was used to analyse the effects of changes to two key grazing-management factors - stocking density and early-season grazing deferment - on biomass dynamics and forage consumption. The simulated results were used to calculate forage deficits and supplementary feed requirements for optimum herd performance during the growth ('green') season and throughout the year. The results revealed a critical stocking density of 0.7 Animal Units (AU)/ha, above which early-season deferment reduced the amount of supplementary feed required to maintain the optimum production of the herd. Optimum stocking is higher when the grassland is used mainly in the highly nutritious green season. Responses of the strongly seasonal Mediterranean grassland to the interaction between stocking density and early-season grazing deferment were expressed by a calibrated model, in terms that determine the efficiency of forage supplementation of the herd during the green season and throughout the year.
Grain production potential (GrPP) is the maximum production in 1 year that can be achieved by land use under the limitations of climate conditions and in the absence of pests and diseases and other factors. Regional GrPP can change over time and there is an urgent need to identify the main factors affecting regional differences in such changes. Therefore, changes in GrPP were studied for six geographical units in Shaanxi Province, with summer maize and winter wheat as the main grain crops. Changes of GrPP during 2000-2015 were simulated by the global aro-ecological zone model. Analysis of modelled GrPP driven by observed changes in climate and land use suggest that over this period GrPP increased to the north but declined to the south of the Qinling Mountains. This is driven mainly by past changes in climate, with modelled GrPP more sensitive to changes in precipitation than temperature in all geographical units except one. Climate change was the main factor affecting GrPP in all geographical units except one; however, model prediction suggests that land use changes had a clear yield-reducing effect in three of the units. It is the conversion from cultivated land to construction land, grassland and woodland that led to the greatest declines in GrPP in these three geographical units. In order to ensure the stable development of regional agriculture and food security, Shaanxi Province should focus on tapping GrPP north of the Qinling Mountains and increasing the conversion rate of GrPP to actual production.
Use of antibiotics as feed additives has been reduced to avoid the hazard of drug residues, and consequently, the search for alternative natural additives has developed. Thus, the aim was to evaluate the influence of royal jelly (RJ) supplementation on milk composition, blood biochemical and antioxidant parameters of lactating ewes. Thirty-six Ossimi ewes were divided randomly into two groups (18 animals each). For a period of 4 weeks, the control group (CON) was fed a basal diet only, while the other group was fed the basal diet and supplemented with a single bolus of RJ (1000 mg/head). The RJ-supplemented ewes produced significantly higher milk protein, fat and total solids than the CON group. The RJ group had a significantly higher red blood cell count, haemoglobin content, haematocrit value and total leucocyte counts, but lower neutrophil to lymphocyte ratio when compared with the control treatment. The RJ group showed significantly higher concentrations of total antioxidant capacity, superoxide dismutase activity and glutathione in the serum compared with the control treatment. In conclusion, RJ supplements can improve the nutritive value of milk fat and the serum antioxidant activities in lactating ewes.
The current paper tackles a critical question in climate change literature of whether farmers will be able to fully adapt to monsoonal climate changes owing to technological developments. Making use of the climate, agricultural and social data of Thailand from 1900 to 2015, this paper estimates a technological change instrumental variable by the growth of the normalized rice yield per hectare of land. The estimation shows that 0.98 of the growth in rice yield can be attributed to technological changes while the rest is accounted for by climate, soils and social factors. In the second stage regressions with the technological change indicator, the paper estimates the normalized numbers of the six most important types of live animals in Thailand: goats, chickens, cattle, sheep, pigs and buffaloes. Over the time period studied, the number of each of these live animals has increased vastly, except for buffaloes. The second-stage regressions show that the growth is largely attributable to technological changes, but monsoonal climate variables such as normalized monsoon precipitation ratio and normalized monsoon temperature are not significant factors. The results indicate that the rate of technological changes is overwhelming the rate of climate change on agriculture in Thailand.
Cultivar mixtures of winter barley and spring barley, together with their component monocultures, were grown in field trials to assess the effect of cultivar combinations on both straw and grain yield. The overall grain yields for all trials were significantly higher for the cultivar mixtures than for the corresponding component monocultures. Also, significant decreases in rhynchosporium disease severity for cultivar mixtures were recorded for most non-fungicide treatments. The size of these responses was often significantly correlated with the component number of the mixtures. The amount of straw produced in mixtures was sometimes changed significantly, but not always in a positive direction and it was only correlated with increasing mixture component number in two environments. No correlation of straw yield potential of cultivars with performance in mixtures was found. Cultivar x cultivar mixture x environment interactions appeared to affect the relative yield of grain and straw differentially and therefore it was not possible to predict the effect of mixtures on the harvest index.
Keratins are the main structural proteins of wool fibres, and it is thought that variation in the keratins may affect wool fibre characteristics. Polymerase chain reaction-single stranded conformational polymorphism (PCR-SSCP) analyses were used to investigate four regions of the ovine keratin gene KRT31 including a portion of the promoter, the exon 1, exon 3 and exon 7 regions. Initially, in a screening panel of 300 New Zealand Romney, Merino and White Dorper sheep obtained from 26 farms, three, two, two and two PCR-SSCP banding patterns were observed for these four regions, respectively. The promoter region, the exon 1 and exon 3 regions contained two single nucleotide polymorphisms (SNPs) and the exon 7 region contained one SNP. The effect of the variation found in the promoter region on wool traits was subsequently investigated in 485 Southdown x Merino-cross lambs from seven sire-lines. The three variants identified in the original 300 sheep (named A, B and C) were observed with frequencies of 56, 29 and 15%, respectively. The presence of A and B had no significant effect on wool traits, but the presence of C was found to be associated with an increase in greasy fleece weight (GFW), clean fleece weight (CFW) and mean staple length (MSL). There was an effect of genotype on CFW and MSL, with BC sheep producing wool of higher CFW and MSL than AA, AB, AC and BB sheep. These results suggest that ovine KRT31 might be a useful candidate gene for improving wool traits.
Many factors, including pathogens, environmental change and breeding techniques, affect honeybee immunity/resistance, so substances and natural supplements that enhance it are desired. To eliminate the impact of unknown external factors, in 2016 a cage experiment was conducted under constant laboratory conditions (35 degrees C, 65% relative humidity). Bees in the control group were fed with sugar dissolved in water at ratio 1:1 ad libitum with no additives, while the other group was fed with sugar syrup (1:1) supplemented with piperine (3 mu g/ml) ad libitum. The piperine-treated workers lived 9 days longer compared to the control group. In the piperine-consuming group, protein concentration and the activities of antioxidative enzymes, such as superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and glutathione S-transferase (GST), were higher than in the control group. The activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) were also higher in the piperine-treated group. Neutral and acidic proteases inhibitors, as well as neutral protease activities, were higher in the haemolymph of the piperine-treated workers than in untreated bees. Acidic protease activities in the haemolymph were higher in untreated workers only on days 18 and 32. Alkaline protease activities in the control bees were higher from day 10. From 10 days old, the total antioxidant capacity level was significantly higher in the haemolymph of piperine-treated workers. Piperine decreased DNA methylation levels significantly in the older bees. The compound could have the potential to be a natural diet supplement increasing apian resistance to stress factors.
A field study to optimize the nitrogen (N) top-dressing mode of panicle fertilization and improve rice yields was conducted in mid-eastern China. Japonica cultivar Yunongjing-6 was grown and panicle N fertilizer was applied at the beginning of the inverted fourth leaf stage using three different modes: manual broadcast application (BA) on the soil surface as a control treatment, deep application during ditching at a depth of 15 cm (DD) and manual BA on the soil surface during deep ditching (BAD). The activity of soil enzymes, including invertase, urease, phosphatase and catalase, was increased significantly at the jointing, booting and grain-filling stages with the DD and BAD treatments compared with the traditional BA mode. The DD and BAD treatments also increased basal internode and neck-panicle internode bleeding intensity. The DD treatment gave the highest crop yield, increasing the yield by 0.63 and 0.31 t/hm2 in 2011 and 2012, respectively, compared with BA. The results suggest that ditching during panicle N fertilizer application after sun-drying of the fields increases rice yields, most likely by improving the activity of soil enzymes and enhancing the physiological activity of roots and grain weight.
An experiment was conducted to determine the effects of supplementing different amounts of daidzein in a diet on the growth performance, blood biochemical parameters and meat quality of finishing beef cattle. Thirty finishing Xianan steers were distributed in three groups equilibrated by weight and fed three different dietary treatments (concentrate ratio = 80%): (1) control; (2) 500 mg/kg daidzein and (3) 1000 mg/kg daidzein, respectively. Steers were slaughtered after an 80-day feeding trial. Results showed that daidzein supplementation had no effect on the final body weight, average daily gain and feed conversion rate of steers. Steers fed with 1000 mg/kg daidzein had greater dry matter intake than those fed with control diets. Compared with the control group, the 1000 mg/kg daidzein group had a higher fat thickness, lower shear force and lightness. The pH, drip loss, cooking loss, redness (a*), yellowness (b*), moisture, ash, crude protein and intramuscular fat of the Longissimus dorsi muscle were unaffected by daidzein supplementation. Compared with the control group, the 1000 mg/kg daidzein group significantly increased the serum concentrations of insulin, free fatty acid and Glutamic-pyruvic transaminase. The 500 mg/kg daidzein group significantly increased the serum concentration of tetraiodothyronine compared with the control group. Supplemental daidzein did not affect the blood antioxidant ability and blood immune parameters in serum. In conclusion, daidzein supplementation above 500 mg/day modifies feed intake and metabolic and hormonal profile, with positive and negative effects on meat quality.
The climate of north-western Spain, with high temperatures and relative humidity during the grapevine vegetative cycle, can especially favour the development of fungal diseases in vineyards. One of the most important diseases is downy mildew, caused by the fungus Plasmopara viticola. The aim of the current study is to propose a system containing phenological data, biological sensors of pathogen indicator and the agrometeorological Goidanich Index in order to optimize the application of downy mildew fungicide treatments. The study was conducted in a vineyard of the 'Ribeiro' Designation of Origin region from 2005 to 2016 during the Vitis vegetative period. Aerobiological sampling was performed using a LANZONI VPPS-2000 volumetric trap. The highest number of infection cycles was recorded during the 2009 harvest, with a total of 16 cycles. Years with fewer infection cycles were 2008, 2011 and 2012 (13 cycles). Primary infections were produced during the third fortnight of April and a high amount of secondary infection cycles were detected by the Goidanich algorithm during the fruit development and berry ripening stages. The best estimators of the P. viticola spore concentrations were the fungus spore levels during the previous day, the average temperature 5 days before and rainfall 2 days before. The regression equation obtained accounted for the 95.9% of the spore concentration variation. The combination of the Goidanich index and biological sensors provides a valuable tool to establish an accurate, modern, integrated downy mildew pest-management strategy.
In alpine regions of the Qinghai-Tibetan Plateau of China, perennial vetch (Vicia unijuga A. Br.) productivity is often low and variable, constrained by the cold and erratic precipitation environment. The aim of the current study was to identify the soil-environmental modifications needed in harsh alpine environmental conditions for improvement of perennial vetch growth, forage biomass production and seed yield. A 3-year field experiment was conducted in an alpine region of China to evaluate the effects of modified soil temperature and moisture conditions generated by three mulching treatments - plastic film mulching (FM), removal of plastic film mulching at the 30% flowering stage and barley straw mulching - on perennial vetch productivity. Higher mean soil temperature and soil water content were recorded in the FM treatment than in the control and other treatments. This enhanced perennial vetch growth, as indicated by higher photosynthetic rate, higher leaf area index and greater above-ground dry matter, and thus higher seed yield and water productivity. Examination by multiple linear regression showed the relative contribution of mean soil temperature to the variations in photosynthetic rate, above-ground dry matter and seed yield were greater than soil water content, whereas the reverse occurred in seeds/pod. In conclusion, the FM treatment provided adequate soil temperature and water resources to improve photosynthetic rate, above-ground dry matter, seed yield and water productivity, and thus increased the productivity potential for perennial vetch in the alpine region. The current research provides scientific support for large-scale perennial vetch cultivation and management in alpine regions.
Although application of organic fertilizers has become a recommended way for developing sustainable agriculture, it is still unclear whether above-ground and below-ground crops have similar responses to chemical fertilizers (CF) and organic manure (OM) under the same farming conditions. The current study investigated soil quality and crop yield response to fertilization of a double-cropping system with rapeseed (above-ground) and sweet potato (below-ground) in an infertile red soil for 2 years (2014-16). Three fertilizer treatments were compared, including CF, OM and organic manure plus chemical fertilizer (MCF). Organic fertilizers (OM and MCF) increased the yield of both above- and below-ground crops and improved soil biochemical properties significantly. The current study also found that soil-chemical properties were the most important and direct factors in increasing crop yields. Also, crop yield was affected indirectly by soil-biological properties, because no significant effects of soil-biological activities on yield were detected after controlling the positive effects of soil-chemical properties. Since organic fertilizers could not only increase crop yield, but also improve soil nutrients and microbial activities efficiently and continuously, OM application is a reliable agricultural practice for both above- and below-ground crops in the red soils of China.
Amendment of recalcitrant organic materials with high carbon/nitrogen (C/N)-ratio may improve and maintain soil labile C for a longer period, thus enhancing the productivity of soils with low fertility; however, immobilization of N may affect the plant growth negatively. To reduce the negative impacts, recalcitrant organic materials can be pre-incubated with N-rich sources or applied in combination with fertilizers. The current study evaluated sawdust biochar (BC) and pre-incubated cattle manure-sawdust mixture (CS) amendments with synthetic fertilizers in improving soil carbon pool, soil fertility and maize (Zea mays L.) yield on a tropical Alfisol. Four treatments: control, site-specific fertilizer (SSF), site-specific fertilizer with sawdust biochar (BC + SSF) or pre-incubated cattle manure-sawdust mixture (CS + SSF), were evaluated for two seasons with maize. The residual effect was evaluated in the third season. During the year of active C application, lability index, C management index and potentially mineralizable N were significantly greater in CS + SSF than BC + SSF treatment. However, the same indices measured in the third season with no further application of amendments were significantly greater in BC + SSF than in CS + SSF treatment, indicating an increase in more recalcitrant C pool with BC amendment. Application of organic amendments improved soil fertility parameters compared with the application of fertilizer alone. Maize yield was significantly increased by fertilizer, with or without organic amendments; with significantly greater yield in BC + SSF than other treatments. Results suggest that soil amendment with BC had greater potential to improve the soil carbon pool and maintain labile carbon for a longer period than a pre-incubated CS.
Despite the global importance of Capsicum species, there is limited information on the indigenous endomycorrhizal fungal association in this crop. Therefore, the diversity and colonization patterns of arbuscular mycorrhizal fungi (AMF) in roots of Naga King chilli (Capsicum chinense) were assessed during pre-flowering, flowering and fruit ripening growth stages under a sub-tropical shifting cultivation system of North Eastern India. All the roots examined had AMF colonization and the presence of Paris-type arbuscular mycorrhizal morphology is reported for the first time in C. chinense. A total of 11 AMF spore morphotypes were isolated from both field and trap culture soils. Maximum AMF spore density and root colonization were recorded during the pre-flowering and flowering stages, respectively. The influence of Funneliformis geosporum, individually or in combination with Pseudomonas fluorescens and Azotobacter chroococcum, on growth and yield of C. chinense, was evaluated in a pot experiment using sterilized and non-sterilized soils. The application of AMF and P. fluorescens to sterilized soil significantly increased the growth, flower and fruit production, and nutrient content of C. chinense. The highest growth rates and yields of C. chinense in non-sterilized soils were achieved when AMF was combined with both P. fluorescens and A. chroococcum. The results of the current study indicate the value of applying microorganisms to improve plant growth and performance in chillies. One of the mechanisms for this could be the facilitated assimilation of nutrients promoted by AMF and bacterial bioinoculants.
The objective of the current paper was to apply mixed models to adjust the growth curve of quail lines for meat and laying hens and present the rates of instantaneous, relative and absolute growth. A database was used with birth weight records up to the 148th day of female quail of the lines for meat and posture. The models evaluated were Brody, Von Bertalanffy, Logistic and Gompertz and the types of residues were constant, combined, proportional and exponential. The Gompertz model with the combined residue presented the best fit. Both strains present a high correlation between the parameters asymptotic weight (A) and average growth rate (k). The two strains presented a different growth profile. However, growth rates allow greater discernment of growth profiles. The meat line presented a higher growth rate (6.95 g/day) than the lineage for laying (3.65 g/day). The relative growth rate was higher for lineage for laying (0.15%) in relation to the lineage for meat (0.13%). The inflection point of both lines is on the first third of the growth curve (up to 15 days). All results suggest that changes in management or nutrition could optimize quail production.
Differences in forage nutritive value between morning and afternoon are related to patterns of dehydration and carbohydrate accumulation throughout the day. In this way, management strategies that maximize grazing time during the afternoon could increase forage nutritive value and consequently nutrient intake. The aim of the current experiment was to evaluate the effect of the time of day (06.00 h [designated AM] or 15.00 h [PM]) that cattle are moved to a new paddock on forage nutritive value, grazing behaviour and animal performance of beef cattle on rotationally stocked Marandu palisadegrass (Brachiaria brizantha cv. Marandu Syn. Urochloa brizantha cv. Marandu) pastures. A spring and summer study was conducted in Pirassununga, SP, Brazil from October 2012 to March 2013 (182 days). Treatments were distributed in a randomized complete block design with three replications. Herbage mass, morphological composition, herbage allowance and stocking rates were similar between treatments during spring and summer. Moving animals to a new paddock, regardless of the time of day - 06.00 h (AM) or 15.00 h (PM) - stimulated grazing, modifying the distribution of meals throughout the day. However, compensatory mechanisms among grazing time, bite rate and forage nutritive value throughout the day operated in order to generate similar performance between animals offered a new paddock in the morning or in the afternoon.
The current work studied the effects of butyric acid (BA) supplementation on the growth performance, carcase characteristics, immunity, gut histology and serum biochemistry of broiler chicken. Four experimental diets were formulated: control, 20 mg bacitracin methylene di-salicylate/kg diet (BMD-supplemented), 3 g BA/kg diet and 4 g BA/kg diet. The results revealed higher body weight gain (BWG) in BA and BMD-supplemented groups. Only BMD supplementation increased the feed intake (FI) of birds, whereas BA supplementation improved feed efficiency. Expression of glucose transporter (GLUT5), sodium-dependent glucose transporter (SGLT1) and peptide transporter (PepT1) were up-regulated due to BMD and BA supplementation. However, at 21 days post-hatching SGLT1 expression in the BMD-supplemented group was down-regulated with respect to the BA-supplemented groups. The 4 g BA/kg diet yielded better humoral and cell-mediated immune responses than the other groups. No dietary effects were observed on carcase characteristics and histomorphometry of jejunum at 7 days post-hatching. However, at 42 days old, the 4 g BA/kg diet increased villus length and width significantly. There was a significant increase in serum protein, albumin, creatinine, aspartate aminotransaminase (AST), phosphorus and calcium due to BA supplementation. However, the reverse trend was observed in serum uric acid and cholesterol, where BA supplementation decreased both and BMD supplementation decreased uric acid levels only. Based on the results it was concluded that 4 g BA/kg diet supplementation in feed is optimal for desirable broiler production.
The use of cactus cladodes in animal feed is well-established in semi-arid areas. The cactus Nopalea cochenillifera (L.) Salm-Dyck cladodes (Nopalea) have high acceptability amongst dairy cows and are resistant to carmine cochineal insects (Dactylopius opuntiae Cockerell), a problem in semi-arid regions, but in regions of prolonged drought, it has lower productivity compared with the cactus Opuntia stricta (Haw.) Haw cladodes (Opuntia), which is also resistant to the insect. The objective of the current study was to evaluate the intake and content of digestible material of dry matter (DM) and its components, feeding behaviour, microbial protein synthesis, nitrogen balance, blood parameters, performance and milk composition of Holstein cows fed a control diet, containing either Nopalea or Opuntia associated with different concentrate levels (225, 275, 325 and 375 g/kg). Ten cows with an initial average milk production of 20 +/- 2.1 kg/day were distributed into a double 5 x 5 Latin square design. Diets containing 775 g roughage/kg and 225 g concentrate/kg promoted similar responses to the analysed variables regardless of the cactus cladode used, except for digestibility of neutral detergent fibre. Diets containing higher proportions of concentrate (325 and 375 g/kg) promoted greater DM intake and 3.5% fat-corrected milk yield. The diet containing Opuntia at 775:225 g/kg roughage:concentrate proportion is as effective as the control diet for Holstein cows producing 20 kg of milk/day. To promote greater milk production, higher proportions of concentrate should be added to diets using Opuntia.
Heading date (HD) and flowering date (FD) are critical for yield potential and stability, so understanding their genetic foundation is of great significance in wheat breeding. Three related recombinant inbred line populations with a common female parent were developed to identify quantitative trait loci (QTL) for HD and FD in four environments. In total, 25 putative additive QTL and 20 pairwise epistatic effect QTL were detected in four environments. The additive QTL were distributed across 17 wheat chromosomes. Of these, QHd-1A, QHd-1D, QHd-2B, QHd-3B, QHd-4A, QHd-4B and QHd-6D were major and stable QTL for HD. QFd-1A, QFd-2B, QFd-4A and QFd-4B were major and stable QTL for FD. In addition, an epistatic interaction test showed that epistasis played important roles in controlling wheat HD and FD. Genetic relationships between HD/FD and five yield-related traits (YRTs) were characterized and ten QTL clusters (C1-C10) simultaneously controlling YRTs and HD/FD were identified. The present work laid a genetic foundation for improving yield potential in wheat molecular breeding programmes.