Background： The potential for acid-detergent insoluble ash （ADIA）, alkaline-peroxide lignin （APL）, and acid-detergent lignin （ADL） to predict fecal output （FO） and dry matter digestibility （DMD） by cattle o...Background： The potential for acid-detergent insoluble ash （ADIA）, alkaline-peroxide lignin （APL）, and acid-detergent lignin （ADL） to predict fecal output （FO） and dry matter digestibility （DMD） by cattle offered bermudagrass [Cynodon doctylon （L） Pers.] hays of different qualities was evaluated. Eight ruminally cannulated cows （594 ± 35.5 kg） were allocated randomly to 4 hay diets： low （L）, medium low （ML）, medium high （MH）, and high （H） crude protein （CP） concentration （79, 111,131, and 164 g CP/kg on a DM basis, respectively）. Diets were offered in 3 periods with 2 diet replicates per period and were rotated across cows between periods. Cows were individually fed 20 g DM/kg of body weight in equal feedings at 08：00 and 16：00 h for a 10-d adaptation followed by a 5-d total fecal collection. Actual DM intake （DMI）, DMD, and FO were determined based on hay offered, ort, and feces excreted. These components were then analyzed for ADL, APL, and ADIA concentration to determine marker recovery and marker-based estimates of FO and DMD. Results： Forage DMI was affected by diet （P = 0.02）, and DMI from MH and H was greater （P 〈 0.05） than from L. Apparent DMD tended （P = 0.08） to differ among diets while FO （P = 0.20） was not affected by diet treatments. Average ADL recovery （1.16） was greater （P 〈 0.05） than that of ADIA （1.03） and APL （1.06）, but ADIA and APL did not differ （P = 0.42）. Estimates of FO and DMD derived using APL and ADIA were not different （P≥0.05） from total fecal collection while those using ADL differed （P 〈 0.05）. There was no diet by marker interaction （P≥ 0.22） for either FO or DMD. Conclusion： Acid-detergent insoluble ash and APL accurately predicted FO and DMD of cattle fed bermudagrass hay of varying nutrient composition. These internal markers may facilitate studies involving large numbers of animals and forages. Results from such studies may be used to develop improved equations to predict energy values of forages based on the relationship of dietary components to digestibility across a wide range of forages.展开更多
Alfalfa is a high quality forage that is not often utilized in the southeastern United States because of its perceived lack of adaptability to the area. However, the risk of growing alfalfa could be partially mitigate...Alfalfa is a high quality forage that is not often utilized in the southeastern United States because of its perceived lack of adaptability to the area. However, the risk of growing alfalfa could be partially mitigated by its inclusion into an existing bermudagrass system that makes up a large portion of pastures and hay fields in Mississippi. Alfalfa was planted into an existing bermudagrass hay field at a rate of 17, 22, 28 and 39 kg·ha-1 in no-till and minimum till sod preparation and analyzed for three growing seasons. Tillage did not affect any of the variables observed but seeding rate and time affected DM (dry matter) yield, forage nutritive value and plot composition. The increasing alfalfa seeding rate increased alfalfa yield in the plot but this was isolated to only the first year. Dry matter yields decreased over the three years due to the decrease in alfalfa composition, but throughout the growing season DM yields increased after the first year suggesting bermudagrass recolonization within the plot. Forage nutritive value was positively affected with as little as 20% of the plot composed of alfalfa suggesting that even thinning stands by the third year might offer economic advantages.展开更多
Background： The effect of time of fecal sampling on the accuracy of acid-detergent insoluble ash （ADIA） and alkaline-peroxide lignin （APL） for the prediction of fecal output （FO） in cattle was evaluated. Eight ...Background： The effect of time of fecal sampling on the accuracy of acid-detergent insoluble ash （ADIA） and alkaline-peroxide lignin （APL） for the prediction of fecal output （FO） in cattle was evaluated. Eight ruminally cannulated cows （594 _＋ 35.5 kg） were allocated randomly to 4 bermudagrass [Cynodon dactylon （L.） Pers.] hay diets markedly different in crude protein concentration （79-164 g/kg） with 2 replicates per diet for 3 periods. Cows were offered hay individually at 20 g DM/kg of body weight daily in equal feedings at 08：00 and 16：00 h for a 10-d adaptation period followed by 5-d of total fecal collection. Fecal grab samples also were taken each day during the fecal collection period at 06：00, 12：00, 18：00, and 24：00 h either directly from the rectum or from freshly voided feces. Samples were composited within cow and time across the 5 d total fecal collection period. Additionally, forage, ort, and fecal samples were analyzed for concentrations of APL and ADIA. Results： Fecal concentrations of ADIA and APL were not affected by sampling time （P 〉 0.22）, even though diet affected （P 〈 0.01） fecal ADIA and APL concentrations. There were no diet x sampling time interactions （P ≥ 0.60）. Estimates of FO and dry matter digestibility （DMD） from ADIA and APL were not affected （P 〉 0.16） by sampling time or the diet x sampling time interaction （P 〉 0.74）. Estimates of FO and DMD from markers from different sampling times or all different combinations of sampling time were not different （P 〉 0.72） from those of total collection among internal markers. Conclusion： Little variation in concentrations of ADIA and APL in daily fecal excretion across time increases flexibility in fecal grab sampling schedules for predicting FO and DMD.展开更多
With the prediction of climate change-induced increases in drought frequency and severity in the southeastern USA, it is important to better understand the risks that drought may pose to NO<sub>3</sub> acc...With the prediction of climate change-induced increases in drought frequency and severity in the southeastern USA, it is important to better understand the risks that drought may pose to NO<sub>3</sub> accumulation in bermudagrass [Cynodon dactylon (L.) Pers.] forage. This report offers observations of NO<sub>3</sub> concentration in Bermudagrass forage samples submitted to the University of Georgia’s Feed and Environmental Water Lab (FEWL) during the extreme to exceptional drought of 2007, the severe drought of 2008, and the four preceding seasons when drought stress was minimal or absent. The probability (P) of a sample being at high risk for nitrate toxicosis was the greatest for the extreme to exceptional drought of 2007 (P = 0.160), slightly lower in the severe drought year of 2008 (P = 0.105), and the lowest for samples from the 2003-2006 growing seasons (P = 0.082) when drought stress was minimal or absent.展开更多
Bermudagrass(Cynodon dactylon(L.)Pers.)is one of the primary perennial forages in the southeastern USA.Newer hybrid cultivars have superior production and nutritive value compared to common ecotypes.However,there are ...Bermudagrass(Cynodon dactylon(L.)Pers.)is one of the primary perennial forages in the southeastern USA.Newer hybrid cultivars have superior production and nutritive value compared to common ecotypes.However,there are many challenges facing bermudagrass production in the region.First,the bermudagrass stem maggot(BSM;Atherigona reversura Villeneuve)has severely damaged bermudagrass throughout the region.Strategically timed pyrethroid applications significantly reduce adult BSM populations,but efforts are needed to develop integrated pest management plans.Second,an increasing number of producers are noting challenges with green-up following winter dormancy.This may be attributed to disease,unbalanced soil fertility,and weed pressure.Perhaps one of the most limiting factors for continued production is the deficit of sprigs and trained personnel to sprig hybrid bermudagrasses.This research is critically important as the need for cold-tolerant bermudagrass is increasing as tall fescue(Lolium arundinaceum(Schreb.)S.J.Darbyshire)is declining due to changes in temperature and precipitation throughout the northern parts of the region.Plant breeders are investigating hybrid bermudagrass at latitudes>35°with respect to freeze or cold tolerance.Despite the many challenges facing hybrid bermudagrass in the southeastern USA,researchers are working to ensure its persistence,productivity,and availability for the future.展开更多
Background:The incorporation of legumes,specifically alfalfa(Medicago sativa L.),into bermudagrass(Cynodon spp.)-based pasture systems in the southeastern United States has increased in recent years as an alternative ...Background:The incorporation of legumes,specifically alfalfa(Medicago sativa L.),into bermudagrass(Cynodon spp.)-based pasture systems in the southeastern United States has increased in recent years as an alternative to synthetic nitrogen(N)fertilization.Methods:A small plot evaluation was conducted in Shorter,Alabama,and Tifton,Georgia,USA,to evaluate the impact of harvest height(HH)and harvest frequency(HF)on agronomic characteristics of alfalfa+bermudagrass mixtures in southeastern United States.Results:Results from both locations revealed that the longer the HF and the shorter the HH,the greater the alfalfa retention was in the stand(p<0.01).HH did not impact any of the reported nutritive value parameters,while longer HF resulted in lower total digestible nutrients,lower crude protein,higher acid detergent fiber,and lower 48 h in vitro dry matter digestibility(p<0.01).Both HH and HF impacted forage accumulation at both locations(p<0.01).HH resulted in different trends at each location,while longer frequencies generally increased forage accumulation.Conclusions:This research confirmed recent findings from comparable evaluations in the southeastern United States,in that increasing HH and decreasing HF improved alfalfa retention while having a negligible effect on nutritive value or forage accumulation.展开更多
As an important second messenger, calcium is involved in plant cold stress response, including chilling（〈20 °C） and freezing（〈0 °C）. In this study, exogenous application of calcium chloride（CaCl2） im...As an important second messenger, calcium is involved in plant cold stress response, including chilling（〈20 °C） and freezing（〈0 °C）. In this study, exogenous application of calcium chloride（CaCl2） improved both chilling and freezing stress tolerances, while ethylene glycol‐bis‐（b‐aminoethyl） ether‐N,N,N,N‐tetraacetic acid（EGTA） reversed CaCl2 effects in bermudagrass（Cynodon dactylon（L.） Pers.）.Pysiological analyses showed that CaCl2 treatment alleviated the reactive oxygen species（ROS） burst and cell damage triggered by chilling stress, via activating antioxidant enzymes,non‐enzymatic glutathione antioxidant pool, while EGTA treatment had the opposite effects. Additionally, comparative proteomic analysis identified 51 differentially expressed proteins that were enriched in redox, tricarboxylicacid cycle,glycolysis, photosynthesis, oxidative pentose phosphate pathway, and amino acid metabolisms. Consistently, 42 metabolites including amino acids, organic acids, sugars, and sugar alcohols were regulated by CaCl2 treatment under control and cold stress conditions, further confirming the Researchcommon modulation of CaCl2 treatment in carbon metabolites and amino acid metabolism. Taken together, this study reported first evidence of the essential and protective roles of endogenous and exogenous calcium in bermudagrass response to cold stress, partially via activation of the antioxidants and modulation of several differentially expressed proteins and metabolic homeostasis in the process of cold acclimation.展开更多
基金supported by University of Arkansas Division of Agriculture and the Robert S.McNamara Fellowship Program of the World Bank
文摘Background： The potential for acid-detergent insoluble ash （ADIA）, alkaline-peroxide lignin （APL）, and acid-detergent lignin （ADL） to predict fecal output （FO） and dry matter digestibility （DMD） by cattle offered bermudagrass [Cynodon doctylon （L） Pers.] hays of different qualities was evaluated. Eight ruminally cannulated cows （594 ± 35.5 kg） were allocated randomly to 4 hay diets： low （L）, medium low （ML）, medium high （MH）, and high （H） crude protein （CP） concentration （79, 111,131, and 164 g CP/kg on a DM basis, respectively）. Diets were offered in 3 periods with 2 diet replicates per period and were rotated across cows between periods. Cows were individually fed 20 g DM/kg of body weight in equal feedings at 08：00 and 16：00 h for a 10-d adaptation followed by a 5-d total fecal collection. Actual DM intake （DMI）, DMD, and FO were determined based on hay offered, ort, and feces excreted. These components were then analyzed for ADL, APL, and ADIA concentration to determine marker recovery and marker-based estimates of FO and DMD. Results： Forage DMI was affected by diet （P = 0.02）, and DMI from MH and H was greater （P 〈 0.05） than from L. Apparent DMD tended （P = 0.08） to differ among diets while FO （P = 0.20） was not affected by diet treatments. Average ADL recovery （1.16） was greater （P 〈 0.05） than that of ADIA （1.03） and APL （1.06）, but ADIA and APL did not differ （P = 0.42）. Estimates of FO and DMD derived using APL and ADIA were not different （P≥0.05） from total fecal collection while those using ADL differed （P 〈 0.05）. There was no diet by marker interaction （P≥ 0.22） for either FO or DMD. Conclusion： Acid-detergent insoluble ash and APL accurately predicted FO and DMD of cattle fed bermudagrass hay of varying nutrient composition. These internal markers may facilitate studies involving large numbers of animals and forages. Results from such studies may be used to develop improved equations to predict energy values of forages based on the relationship of dietary components to digestibility across a wide range of forages.
文摘Alfalfa is a high quality forage that is not often utilized in the southeastern United States because of its perceived lack of adaptability to the area. However, the risk of growing alfalfa could be partially mitigated by its inclusion into an existing bermudagrass system that makes up a large portion of pastures and hay fields in Mississippi. Alfalfa was planted into an existing bermudagrass hay field at a rate of 17, 22, 28 and 39 kg·ha-1 in no-till and minimum till sod preparation and analyzed for three growing seasons. Tillage did not affect any of the variables observed but seeding rate and time affected DM (dry matter) yield, forage nutritive value and plot composition. The increasing alfalfa seeding rate increased alfalfa yield in the plot but this was isolated to only the first year. Dry matter yields decreased over the three years due to the decrease in alfalfa composition, but throughout the growing season DM yields increased after the first year suggesting bermudagrass recolonization within the plot. Forage nutritive value was positively affected with as little as 20% of the plot composed of alfalfa suggesting that even thinning stands by the third year might offer economic advantages.
基金supported by University of Arkansas Division of Agriculturethe Robert S.McNamara Fellowship program of the World Bank
文摘Background： The effect of time of fecal sampling on the accuracy of acid-detergent insoluble ash （ADIA） and alkaline-peroxide lignin （APL） for the prediction of fecal output （FO） in cattle was evaluated. Eight ruminally cannulated cows （594 _＋ 35.5 kg） were allocated randomly to 4 bermudagrass [Cynodon dactylon （L.） Pers.] hay diets markedly different in crude protein concentration （79-164 g/kg） with 2 replicates per diet for 3 periods. Cows were offered hay individually at 20 g DM/kg of body weight daily in equal feedings at 08：00 and 16：00 h for a 10-d adaptation period followed by 5-d of total fecal collection. Fecal grab samples also were taken each day during the fecal collection period at 06：00, 12：00, 18：00, and 24：00 h either directly from the rectum or from freshly voided feces. Samples were composited within cow and time across the 5 d total fecal collection period. Additionally, forage, ort, and fecal samples were analyzed for concentrations of APL and ADIA. Results： Fecal concentrations of ADIA and APL were not affected by sampling time （P 〉 0.22）, even though diet affected （P 〈 0.01） fecal ADIA and APL concentrations. There were no diet x sampling time interactions （P ≥ 0.60）. Estimates of FO and dry matter digestibility （DMD） from ADIA and APL were not affected （P 〉 0.16） by sampling time or the diet x sampling time interaction （P 〉 0.74）. Estimates of FO and DMD from markers from different sampling times or all different combinations of sampling time were not different （P 〉 0.72） from those of total collection among internal markers. Conclusion： Little variation in concentrations of ADIA and APL in daily fecal excretion across time increases flexibility in fecal grab sampling schedules for predicting FO and DMD.
文摘With the prediction of climate change-induced increases in drought frequency and severity in the southeastern USA, it is important to better understand the risks that drought may pose to NO<sub>3</sub> accumulation in bermudagrass [Cynodon dactylon (L.) Pers.] forage. This report offers observations of NO<sub>3</sub> concentration in Bermudagrass forage samples submitted to the University of Georgia’s Feed and Environmental Water Lab (FEWL) during the extreme to exceptional drought of 2007, the severe drought of 2008, and the four preceding seasons when drought stress was minimal or absent. The probability (P) of a sample being at high risk for nitrate toxicosis was the greatest for the extreme to exceptional drought of 2007 (P = 0.160), slightly lower in the severe drought year of 2008 (P = 0.105), and the lowest for samples from the 2003-2006 growing seasons (P = 0.082) when drought stress was minimal or absent.
基金National Institute of Food and Agriculture,Grant/Award Number:2017-70005-27089Georgia Seed DevelopmentGeorgia Beef Commission。
文摘Bermudagrass(Cynodon dactylon(L.)Pers.)is one of the primary perennial forages in the southeastern USA.Newer hybrid cultivars have superior production and nutritive value compared to common ecotypes.However,there are many challenges facing bermudagrass production in the region.First,the bermudagrass stem maggot(BSM;Atherigona reversura Villeneuve)has severely damaged bermudagrass throughout the region.Strategically timed pyrethroid applications significantly reduce adult BSM populations,but efforts are needed to develop integrated pest management plans.Second,an increasing number of producers are noting challenges with green-up following winter dormancy.This may be attributed to disease,unbalanced soil fertility,and weed pressure.Perhaps one of the most limiting factors for continued production is the deficit of sprigs and trained personnel to sprig hybrid bermudagrasses.This research is critically important as the need for cold-tolerant bermudagrass is increasing as tall fescue(Lolium arundinaceum(Schreb.)S.J.Darbyshire)is declining due to changes in temperature and precipitation throughout the northern parts of the region.Plant breeders are investigating hybrid bermudagrass at latitudes>35°with respect to freeze or cold tolerance.Despite the many challenges facing hybrid bermudagrass in the southeastern USA,researchers are working to ensure its persistence,productivity,and availability for the future.
基金National Institute of Food and Agriculture,Grant/Award Number:2017-70005-27089。
文摘Background:The incorporation of legumes,specifically alfalfa(Medicago sativa L.),into bermudagrass(Cynodon spp.)-based pasture systems in the southeastern United States has increased in recent years as an alternative to synthetic nitrogen(N)fertilization.Methods:A small plot evaluation was conducted in Shorter,Alabama,and Tifton,Georgia,USA,to evaluate the impact of harvest height(HH)and harvest frequency(HF)on agronomic characteristics of alfalfa+bermudagrass mixtures in southeastern United States.Results:Results from both locations revealed that the longer the HF and the shorter the HH,the greater the alfalfa retention was in the stand(p<0.01).HH did not impact any of the reported nutritive value parameters,while longer HF resulted in lower total digestible nutrients,lower crude protein,higher acid detergent fiber,and lower 48 h in vitro dry matter digestibility(p<0.01).Both HH and HF impacted forage accumulation at both locations(p<0.01).HH resulted in different trends at each location,while longer frequencies generally increased forage accumulation.Conclusions:This research confirmed recent findings from comparable evaluations in the southeastern United States,in that increasing HH and decreasing HF improved alfalfa retention while having a negligible effect on nutritive value or forage accumulation.
基金supported by "the Hundred Talents Program," the Knowledge Innovative Key Program of the Chinese Academy of Sciences (54Y154761O01076 and Y329631O0263) to Z.C.the National Natural Science Foundation of China (31200194)+1 种基金the outstanding young talent program of Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture (Y352811O03)Youth Innovation Promotion Association of the Chinese Academy of Sciences to H.S.
文摘As an important second messenger, calcium is involved in plant cold stress response, including chilling（〈20 °C） and freezing（〈0 °C）. In this study, exogenous application of calcium chloride（CaCl2） improved both chilling and freezing stress tolerances, while ethylene glycol‐bis‐（b‐aminoethyl） ether‐N,N,N,N‐tetraacetic acid（EGTA） reversed CaCl2 effects in bermudagrass（Cynodon dactylon（L.） Pers.）.Pysiological analyses showed that CaCl2 treatment alleviated the reactive oxygen species（ROS） burst and cell damage triggered by chilling stress, via activating antioxidant enzymes,non‐enzymatic glutathione antioxidant pool, while EGTA treatment had the opposite effects. Additionally, comparative proteomic analysis identified 51 differentially expressed proteins that were enriched in redox, tricarboxylicacid cycle,glycolysis, photosynthesis, oxidative pentose phosphate pathway, and amino acid metabolisms. Consistently, 42 metabolites including amino acids, organic acids, sugars, and sugar alcohols were regulated by CaCl2 treatment under control and cold stress conditions, further confirming the Researchcommon modulation of CaCl2 treatment in carbon metabolites and amino acid metabolism. Taken together, this study reported first evidence of the essential and protective roles of endogenous and exogenous calcium in bermudagrass response to cold stress, partially via activation of the antioxidants and modulation of several differentially expressed proteins and metabolic homeostasis in the process of cold acclimation.
