Benefits of the red seaweed <i>Asparagopsis</i> <i>taxiformis</i> as an ingredient to manage methane (CH<sub>4</sub>) emissions from the red meat and dairy industries continue to ev...Benefits of the red seaweed <i>Asparagopsis</i> <i>taxiformis</i> as an ingredient to manage methane (CH<sub>4</sub>) emissions from the red meat and dairy industries continue to evolve. <i>Asparagopsis</i> has been demonstrated to eliminate enteric CH<sub>4</sub> emissions <i>in</i> <i>vitro</i> and reduce it greater than 80% in animals. Variability in animal studies is suspected to be associated with variable inclusion and proportions of grass and grain in the diet. This <i>in</i> <i>vitro</i> study aimed to elucidate effects of gradient grass to grain proportions in the fermentation using five steps from 100% Rhodes grass (RG) to 100% barley grain (BG). Gradient inclusion of <i>Asparagopsis</i> was in six steps of Control with no inclusion (C), Low (L), Low-Medium (LM), Medium (M), Medium-High (MH), and High (H) levels tested in three fermentation durations (24 h, 48 h, 72 h). There was significant effect of RG/BG and inclusion of <i>Asparagopsis</i> such that CH<sub>4</sub> production decreased with increasing <i>Asparagopsis</i> independent of RG/BG;however, there was enhanced reduction at greater proportions of BG. Thus, the level of <i>Asparagopsis</i> required to completely inhibit CH<sub>4</sub> production <i>in</i> <i>vitro</i> was decreased with decreasing RG/BG. Increasing the duration of fermentation had greatest effect on CH<sub>4</sub> at C, L, and LM levels of <i>Asparagopsis</i> independent of RG/BG, although magnitude of CH<sub>4</sub> production was greater for higher proportions of BG for the C and L levels. Digestibility of <i>in</i> <i>vitro</i> substrate increased with fermentation duration and increasing BG;however, there was no change associated with inclusion levels of <i>Asparagopsis</i>. Increases in total volatile fatty acids (tVFA) were observed with increased fermentation duration and concomitant with increasing substrate digestion. Increasing proportions of BG induced increase in tVFA. In contrast, and independent of changes in substrate, increasing inclusion of <i>Asparagopsis</i> had little effect on tVFA. The acetic and propionic acid ratio (AA:PA) decreased with decreasing RG/BG and increasing <i>Asparagopsis</i>. This pattern was most pronounced with 100% BG and MH-H <i>Asparagopsis</i> levels. Compared to control, there was decrease in the AA:PA ratio with addition of even L levels of <i>Asparagopsis</i> and with L compared to LM inclusion levels. Increasing levels of BG and <i>Asparagopsis</i> resulted in significant decreases in AA:PA ratios and CH4 production. This study has confirmed that gradient levels (ratio) of grass and grain in a feed mix impact the antimethanogenic efficacy of <i>Asparagopsis</i> during <i>in</i> <i>vitro</i> fermentation with rumen fluid.展开更多
一前言在微生物杀虫剂中,苏芸金杆菌是最成功的商品制剂。活孢子和足量的σ-內毒素是该产品主要的毒素成分。众所周知,产品的毒力是根据菌株(不同菌株及同一菌株的不同株系)、培养基和生长条件的不同而异(Dulmage and Rhodes,1971)。但...一前言在微生物杀虫剂中,苏芸金杆菌是最成功的商品制剂。活孢子和足量的σ-內毒素是该产品主要的毒素成分。众所周知,产品的毒力是根据菌株(不同菌株及同一菌株的不同株系)、培养基和生长条件的不同而异(Dulmage and Rhodes,1971)。但是,使用相同菌株在体外和体内条件下的培养物所进行的毒性比较尚未见报道。最近。展开更多
Feed scarcity is a major challenge in smallholder production systems especially during the dry season. Sweet potato vines (SPV) contribute over 40% of the crop residues fed to dairy cattle but they are highly perishab...Feed scarcity is a major challenge in smallholder production systems especially during the dry season. Sweet potato vines (SPV) contribute over 40% of the crop residues fed to dairy cattle but they are highly perishable resulting into losses of about 24% per season. Ensiling SPV mitigates seasonal feed shortages and assists in coping with seasonal feed price fluctuations. This study was conducted to evaluate the effect of sweet potato vines silage (SPVS) supplementation on the performance of lactating Ankole × Friesian crossbred dairy cattle. Four primiparous cows in early lactation were randomly allotted a basal diet of Rhodes grass (Chloris gayana) hay supplemented with dairy pellets and four graded levels of SPVS (0, 100, 200 and 300 g/kg of the daily ration) in a 4 × 4 Latin square design. The animals were given a one-week adaptation period followed by a two weeks data collection period for each diet. Dry matter intake (DMI), live weight changes, milk yield and composition were determined. Dry matter intake improved with addition of SPVS (P ≤ 0.05), with intake being highest (11.9 kg) in cows that were fed the highest SPVS level and lowest in cows that were not given SPVS (6.8 kg). Although animals on diets with 0, 100, 200 g of SPVS/kg of daily ration lost weight, there were no significant differences (P ≥ 0.05) in body weight changes across all treatments. Milk yield increased with SPVS supplementation by 1.5 - 1.7 kg per cow per day but there were no significant differences between the different SPVS supplementation levels. Milk fat and solids-non-fat differed (P ≤ 0.05) across the four diets but there was no consistent trend observed. Considering profit margins, supplementing dairy cows with SPVS at a level of 100 g/kg of daily ration was the most profitable at Uganda shillings 1290 (0.344 USD) per cow per day. In conclusion, SPVS supplementation improved DMI and milk yield but supplementation beyond 100 g/kg of the daily feed intake was not cost-effective.展开更多
Use of nonlinear mathematical models has been majorly based on in vitro gas production(GP) data generated when substrates are incubated with rumen liquor from fistulated steers. However,existing evidence suggests that...Use of nonlinear mathematical models has been majorly based on in vitro gas production(GP) data generated when substrates are incubated with rumen liquor from fistulated steers. However,existing evidence suggests that rumen liquor from slaughtered cattle of unknown dietary history also generates quantifiable in vitro GP data. Fitting and description of GP data obtained from 4 diets incubated with rumen liquor from slaughtered cattle was evaluated using single-pool exponential model with discrete lag time(EXPL), logistic(LOG), Groot's(GRTS) and Gompertz(GOMP) models. Diets were formulated by varying proportions of Rhodes grass(Chloris gayana) hay and a concentrate mixed on dry matter basis to be: 1,000 g/kg Rhodes grass hay(RGH) and 0 of the concentrate(D1), 900 g/kg RGH and 100 g/kg concentrate(D2), 800 g/kg RGH and 200 g/kg concentrate(D3), 700 g/kg RGH and 300 g/kg concentrate(D4). Dietary kinetics for the models were determined by measuring GP at 2,4.8,10.18,24.36,48.72,96 and 120 h. Model comparison was based on derived GP kinetics, graphical analysis of observed versus predicted GP profiles plus residual distribution and goodness-of-fit from analysis of root mean square error(RMSE), adjusted coefficient of determination(Adj-R^2) and Akaike's information criterion(AIC). Asymptotic GP, half-life and fractional rate of GP differed(P < 0.001) among the 4 models. The RMSE, Adj-R^2 and AIC ranged from 1.555 to 4.429,0.906 to0.984 and 2.452 to 15.874, respectively, forall diets compared across the 4 models. Based on the goodness-of-fit statistical criterion, GP profiles of D1 were more appropriately fitted and described by GRTS and GOMP than the EXPLand LOG models. The GRTS model had the lowest AIC value for D2(2.452). Although GRTS model had the most homogenous residual dispersion for the 4 diets, all the 4 models exhibited a sigmoidal behavior.Therefore, rumen liquor from slaughtered cattle of unknown dietary history can be used to derive nutritionally important feed parameters, but choice of the most appropriate model should be made based on fitting criteria and dietary substrates incubated.展开更多
一依纳爵·罗耀拉(Ignatius de Loyola)创办的耶稣会,自诞生之日起就把培养当地耶稣会士和世俗神职人员纳入计划之中,"一名诞生于阿维尼翁和西班牙犹太血统的法国耶稣会士罗德先(Alexandre Rhodes)神父,曾在这方面发出过多次呼...一依纳爵·罗耀拉(Ignatius de Loyola)创办的耶稣会,自诞生之日起就把培养当地耶稣会士和世俗神职人员纳入计划之中,"一名诞生于阿维尼翁和西班牙犹太血统的法国耶稣会士罗德先(Alexandre Rhodes)神父,曾在这方面发出过多次呼吁"。关心中国教务的神父们渴望将这一计划付诸实施,他们认为中国人猜忌心严重,对外国人极不信任。展开更多
文摘素有＂本科生诺贝尔奖＂之美誉的罗德奖学金（Rhodes Scholarships）,近日在中国大陆地区正式开放其2017年的奖学金申请名额。罗德奖学金由罗德基金会设立。罗德基金会成立于1903年,根据施素·罗德（Cecil Rhodes）遗愿中的条款以及随后英国的国会法案（Acts of Parliament）创建,
文摘Benefits of the red seaweed <i>Asparagopsis</i> <i>taxiformis</i> as an ingredient to manage methane (CH<sub>4</sub>) emissions from the red meat and dairy industries continue to evolve. <i>Asparagopsis</i> has been demonstrated to eliminate enteric CH<sub>4</sub> emissions <i>in</i> <i>vitro</i> and reduce it greater than 80% in animals. Variability in animal studies is suspected to be associated with variable inclusion and proportions of grass and grain in the diet. This <i>in</i> <i>vitro</i> study aimed to elucidate effects of gradient grass to grain proportions in the fermentation using five steps from 100% Rhodes grass (RG) to 100% barley grain (BG). Gradient inclusion of <i>Asparagopsis</i> was in six steps of Control with no inclusion (C), Low (L), Low-Medium (LM), Medium (M), Medium-High (MH), and High (H) levels tested in three fermentation durations (24 h, 48 h, 72 h). There was significant effect of RG/BG and inclusion of <i>Asparagopsis</i> such that CH<sub>4</sub> production decreased with increasing <i>Asparagopsis</i> independent of RG/BG;however, there was enhanced reduction at greater proportions of BG. Thus, the level of <i>Asparagopsis</i> required to completely inhibit CH<sub>4</sub> production <i>in</i> <i>vitro</i> was decreased with decreasing RG/BG. Increasing the duration of fermentation had greatest effect on CH<sub>4</sub> at C, L, and LM levels of <i>Asparagopsis</i> independent of RG/BG, although magnitude of CH<sub>4</sub> production was greater for higher proportions of BG for the C and L levels. Digestibility of <i>in</i> <i>vitro</i> substrate increased with fermentation duration and increasing BG;however, there was no change associated with inclusion levels of <i>Asparagopsis</i>. Increases in total volatile fatty acids (tVFA) were observed with increased fermentation duration and concomitant with increasing substrate digestion. Increasing proportions of BG induced increase in tVFA. In contrast, and independent of changes in substrate, increasing inclusion of <i>Asparagopsis</i> had little effect on tVFA. The acetic and propionic acid ratio (AA:PA) decreased with decreasing RG/BG and increasing <i>Asparagopsis</i>. This pattern was most pronounced with 100% BG and MH-H <i>Asparagopsis</i> levels. Compared to control, there was decrease in the AA:PA ratio with addition of even L levels of <i>Asparagopsis</i> and with L compared to LM inclusion levels. Increasing levels of BG and <i>Asparagopsis</i> resulted in significant decreases in AA:PA ratios and CH4 production. This study has confirmed that gradient levels (ratio) of grass and grain in a feed mix impact the antimethanogenic efficacy of <i>Asparagopsis</i> during <i>in</i> <i>vitro</i> fermentation with rumen fluid.
文摘一前言在微生物杀虫剂中,苏芸金杆菌是最成功的商品制剂。活孢子和足量的σ-內毒素是该产品主要的毒素成分。众所周知,产品的毒力是根据菌株(不同菌株及同一菌株的不同株系)、培养基和生长条件的不同而异(Dulmage and Rhodes,1971)。但是,使用相同菌株在体外和体内条件下的培养物所进行的毒性比较尚未见报道。最近。
文摘Feed scarcity is a major challenge in smallholder production systems especially during the dry season. Sweet potato vines (SPV) contribute over 40% of the crop residues fed to dairy cattle but they are highly perishable resulting into losses of about 24% per season. Ensiling SPV mitigates seasonal feed shortages and assists in coping with seasonal feed price fluctuations. This study was conducted to evaluate the effect of sweet potato vines silage (SPVS) supplementation on the performance of lactating Ankole × Friesian crossbred dairy cattle. Four primiparous cows in early lactation were randomly allotted a basal diet of Rhodes grass (Chloris gayana) hay supplemented with dairy pellets and four graded levels of SPVS (0, 100, 200 and 300 g/kg of the daily ration) in a 4 × 4 Latin square design. The animals were given a one-week adaptation period followed by a two weeks data collection period for each diet. Dry matter intake (DMI), live weight changes, milk yield and composition were determined. Dry matter intake improved with addition of SPVS (P ≤ 0.05), with intake being highest (11.9 kg) in cows that were fed the highest SPVS level and lowest in cows that were not given SPVS (6.8 kg). Although animals on diets with 0, 100, 200 g of SPVS/kg of daily ration lost weight, there were no significant differences (P ≥ 0.05) in body weight changes across all treatments. Milk yield increased with SPVS supplementation by 1.5 - 1.7 kg per cow per day but there were no significant differences between the different SPVS supplementation levels. Milk fat and solids-non-fat differed (P ≤ 0.05) across the four diets but there was no consistent trend observed. Considering profit margins, supplementing dairy cows with SPVS at a level of 100 g/kg of daily ration was the most profitable at Uganda shillings 1290 (0.344 USD) per cow per day. In conclusion, SPVS supplementation improved DMI and milk yield but supplementation beyond 100 g/kg of the daily feed intake was not cost-effective.
基金the Livestock and Fisheries Programme(LFP 04) of the Association for Strengthening Agricultural Research in Eastern and Central Africa(ASARECA-RC12_LFP-04 under the auspices of the World Bank for providing financial support to undertake this research
文摘Use of nonlinear mathematical models has been majorly based on in vitro gas production(GP) data generated when substrates are incubated with rumen liquor from fistulated steers. However,existing evidence suggests that rumen liquor from slaughtered cattle of unknown dietary history also generates quantifiable in vitro GP data. Fitting and description of GP data obtained from 4 diets incubated with rumen liquor from slaughtered cattle was evaluated using single-pool exponential model with discrete lag time(EXPL), logistic(LOG), Groot's(GRTS) and Gompertz(GOMP) models. Diets were formulated by varying proportions of Rhodes grass(Chloris gayana) hay and a concentrate mixed on dry matter basis to be: 1,000 g/kg Rhodes grass hay(RGH) and 0 of the concentrate(D1), 900 g/kg RGH and 100 g/kg concentrate(D2), 800 g/kg RGH and 200 g/kg concentrate(D3), 700 g/kg RGH and 300 g/kg concentrate(D4). Dietary kinetics for the models were determined by measuring GP at 2,4.8,10.18,24.36,48.72,96 and 120 h. Model comparison was based on derived GP kinetics, graphical analysis of observed versus predicted GP profiles plus residual distribution and goodness-of-fit from analysis of root mean square error(RMSE), adjusted coefficient of determination(Adj-R^2) and Akaike's information criterion(AIC). Asymptotic GP, half-life and fractional rate of GP differed(P < 0.001) among the 4 models. The RMSE, Adj-R^2 and AIC ranged from 1.555 to 4.429,0.906 to0.984 and 2.452 to 15.874, respectively, forall diets compared across the 4 models. Based on the goodness-of-fit statistical criterion, GP profiles of D1 were more appropriately fitted and described by GRTS and GOMP than the EXPLand LOG models. The GRTS model had the lowest AIC value for D2(2.452). Although GRTS model had the most homogenous residual dispersion for the 4 diets, all the 4 models exhibited a sigmoidal behavior.Therefore, rumen liquor from slaughtered cattle of unknown dietary history can be used to derive nutritionally important feed parameters, but choice of the most appropriate model should be made based on fitting criteria and dietary substrates incubated.
文摘一依纳爵·罗耀拉(Ignatius de Loyola)创办的耶稣会,自诞生之日起就把培养当地耶稣会士和世俗神职人员纳入计划之中,"一名诞生于阿维尼翁和西班牙犹太血统的法国耶稣会士罗德先(Alexandre Rhodes)神父,曾在这方面发出过多次呼吁"。关心中国教务的神父们渴望将这一计划付诸实施,他们认为中国人猜忌心严重,对外国人极不信任。
