Background: Starch is the main source of energy in commonly used pig diets.Besides effects related to the extent of starch digestion,also several effects related to variation in digestion rate have recently been demon...Background: Starch is the main source of energy in commonly used pig diets.Besides effects related to the extent of starch digestion,also several effects related to variation in digestion rate have recently been demonstrated in non-ruminants.Different rates of starch digestion in animals and in in vitro models have been reported,depending on the botanic origin of starch.Starches from different botanic sources differ widely in structural and molecular properties.Predicting the effect of starch properties on in vitro digestion kinetics based on existing literature is hampered by incomplete characterization of the starches,or by a selective choice of starches from a limited number of botanic sources.This research aimed to analyse the relationships between starch properties and in vitro digestion kinetics of pure starches isolated from a broad range of botanic origins,which are used in non-ruminant diets or have a potential to be used in the future.Therefore we studied starch digestion kinetics of potato,pea,corn,rice,barley,and wheat starches,and analysed the granule diameter,number of pores,type and amount of crystalline structure,amylose content and amylopectin side-chain length of all starches.Results: Multivariate analysis revealed strong correlations among starch properties,leading us to conclude that effects of most starch characteristics are strongly interrelated.Across all analysed botanic sources,crystalline type and amylopectin chain length showed the strongest correlation with in vitro digestion kinetics.Increased percentages of A–type crystalline structure and amylopectin side chains of DP 6–24 both increased the rate of digestion.In addition,within,but not across,(clusters of) botanic sources,a decrease in amylose content and increase in number of pores correlated positively with digestion kinetics.Conclusion: The type of crystalline structure and amylopectin chain length distribution of starch correlate significantly with digestion kinetics of starches across botanic sources in an in vitro pig model.Variation in digestion kinetics across botanic sources is not additively explained by other starch properties measured,but appears to be confined within botanical sources.展开更多
Background: The present work investigated the influence of lignin content and composition in the fungal treatment of lignocellulosic biomass in order to improve rumen degradability. Wheat straw and wood chips,differi...Background: The present work investigated the influence of lignin content and composition in the fungal treatment of lignocellulosic biomass in order to improve rumen degradability. Wheat straw and wood chips,differing in lignin composition, were treated with Lentinula edodes for 0, 2, 4, 8 and 12 wk and the changes occurring during fungal degradation were analyzed using pyrolysis-gas chromatography-mass spectrometry and detergent fiber analysis.Results: L. edodes preferentially degraded lignin, with only limited cellulose degradation, in wheat straw and wood chips, leaving a substrate enriched in cellulose. Syringyl(S)-lignin units were preferentially degraded than guaiacyl(G)-lignin units, resulting in a decreased S/G ratio. A decreasing S/G ratio(wheat straw: r =-0.72, wood chips: r =-0.75) and selective lignin degradation(wheat straw: r =-0.69, wood chips: r =-0.88) were correlated with in vitro gas production(IVGP), a good indicator for rumen degradability.Conclusions: L. edodes treatment increased the IVGP of wheat straw and wood chips. Effects on IVGP were similar for wheat straw and wood chips indicating that lignin content and 3D-structure of cell walls influence in vitro rumen degradability more than lignin composition.展开更多
Background: The aim of this study was to optimize the fungal treatment of lignocellulosic biomass by stimulating the colonization. Wheat straw and wood chips were treated with Ceriporiopsis subvermispora and Lentinul...Background: The aim of this study was to optimize the fungal treatment of lignocellulosic biomass by stimulating the colonization. Wheat straw and wood chips were treated with Ceriporiopsis subvermispora and Lentinula edodes with various amounts of colonized millet grains(0.5, 1.5 or 3.0 % per g of wet weight of substrate) added to the substrates. Also, wheat straw and wood chips were chopped to either 0.5 or 2 cm.Effectiveness of the fungal treatment after 0, 2, 4, 6, or 8 wk of incubation was determined by changes in chemical composition, in vitro gas production(IVGP) as a measure for rumen degradability, and ergosterol content as a measure of fungal biomass.Results: Incomplete colonization was observed for C. subvermispora treated wheat straw and L. edodes treated wood chips. The different particle sizes and amounts of inoculum tested, had no significant effects on the chemical composition and the IVGP of C. subvermispora treated wood chips. Particle size did influence L.edodes treatment of wheat straw. The L. edodes treatment of 2 cm wheat straw resulted in a more selective delignification and a higher IVGP than the smaller particles. Addition of 1.5 % or 3 % L. edodes inoculum to wheat straw resulted in more selective delignification and a higher IVGP than addition of 0.5 % inoculum.Conclusion: Particle size and amount of inoculum did not have an effect on C. subvermispora treatment of wood chips. At least 1.5 % L. edodes colonized millet grains should be added to 2 cm wheat straw to result in an increased IVGP and acid detergent lignin(ADL) degradation.展开更多
Background: Characterising the regulation of milk component synthesis in response to macronutrient supply is critical for understanding the implications of nutritional interventions on milk production. Gene expression...Background: Characterising the regulation of milk component synthesis in response to macronutrient supply is critical for understanding the implications of nutritional interventions on milk production. Gene expression in mammary gland secretory cells was measured using RNA isolated from milk fat globules from 6 Holstein-Friesian cows receiving 5-d abomasal infusions of saline, essential amino acids(AA), or glucose(GG) or palm olein(LG)without(LAA) or with(HAA) essential AA, according to a 6 × 6 Latin square design. RNA was isolated from milk fat samples collected on d 5 of infusion and subjected to real-time quantitative PCR. We hypothesised that m RNA expression of genes involved in de novo milk fatty acid(FA) synthesis would be differently affected by GG and LG,and that expression of genes regulating transfer of tricarboxylic acid cycle intermediates would increase at the HAA level. We also hypothesised that the HAA level would affect genes regulating endoplasmic reticulum(ER)homeostasis but would not affect genes related to the mechanistic target of rapamycin complex 1(m TORC1) or the integrated stress response(ISR) network.Results: Infusion of GG did not affect de novo milk FA yield but decreased expression of FA synthase(FASN).Infusion of LG decreased de novo FA yield and tended to decrease expression of acetyl-Co A carboxylase 1(ACC1).The HAA level increased both de novo FA yield and expression of ACC1, and tended to decrease expression of mitochondrial phosphoenolpyruvate carboxykinase(PCK2). m RNA expression of m TORC1 signaling participants was not affected by GG, LG, or AA level. Expression of the ε subunit of the ISR constituent eukaryotic translation initiation factor 2 B(EIF2 B5) tended to increase at the HAA level, but only in the presence of LG. X-box binding protein 1(XBP1) m RNA was activated in response to LG and the HAA level.Conclusions: Results show that expression of genes involved in de novo FA synthesis responded to glucogenic,lipogenic, and aminogenic substrates, whereas genes regulating intermediate flux through the tricarboxylic acid cycle were not majorly affected. Results also suggest that after 5 d of AA supplementation, milk protein synthesis is supported by enhanced ER biogenesis instead of signaling through the mTORC1 or ISR networks.展开更多
Background: Toasting during the production of rapeseed meal(RSM) decreases ileal crude protein(CP) and amino acid(AA) digestibility. The mechanisms that determine the decrease in digestibility have not been ful...Background: Toasting during the production of rapeseed meal(RSM) decreases ileal crude protein(CP) and amino acid(AA) digestibility. The mechanisms that determine the decrease in digestibility have not been fully elucidated. A high protein quality, low-denatured, RSM was produced and toasted up to 120 min, with samples taken every 20 min. The aim of this study was to characterize secondary structure and chemical changes of proteins and glucosinolates occurring during toasting of RSM and the effects on its in vitro CP digestibility.Results: The decrease in protein solubility and the increase of intermolecular β-sheets with increasing toasting time were indications of protein aggregation. The contents of NDF and ADIN increased with increasing toasting time.Contents of arginine, lysine and O-methylisourea reactive lysine(OMIU-RL) linearly decreased with increasing toasting time, with a larger decrease of OMIU-RL than lysine. First-order reactions calculated from the measured parameters show that glucosinolates were degraded faster than lysine, OMIU-RL and arginine and that physical changes to proteins seem to occur before chemical changes during toasting. Despite the drastic physical and chemical changes noticed on the proteins, the coefficient of in vitro CP digestibility ranged from 0.776 to 0.750 and there were no effects on the extent of protein hydrolysis after 120 min. In contrast, the rate of protein hydrolysis linearly decreased with increasing toasting time, which was largely correlated to the decrease in protein solubility, lysine and OMIU-RL observed. Rate of protein hydrolysis was more than 2-fold higher for the untoasted RSM compared to the 120 min toasted material.Conclusions: Increasing the toasting time for the production of RSM causes physical and chemical changes to the proteins that decrease the rate of protein hydrolysis. The observed decrease in the rate of protein hydrolysis could impact protein digestion and utilization.展开更多
Edible insects are advocated as sustainable and healthy food and feed.However,commercially produced insects are often low in n‐3 fatty acids and have suboptimal n‐6/n‐3 ratios.A certain amount and proportion of the...Edible insects are advocated as sustainable and healthy food and feed.However,commercially produced insects are often low in n‐3 fatty acids and have suboptimal n‐6/n‐3 ratios.A certain amount and proportion of these FAs is required to optimize human health.Flaxseed oil consists primarily(57%)out of alpha‐linolenic acid.An experiment was conducted to quantify the effect of flaxseed oil provision on fatty acid composition and to determine the quantity needed to attain a beneficial n‐6/n‐3 ratio.Three species were used in the experiment:house crickets(Acheta domesticus[L.]),lesser mealworms(Alphitobius diaperinus[Pfanzer])and black soldier flies(Hermetia illucens[L.]).These were provided with either a control diet or a diet enriched with 1%,2%,or 4%flaxseed oil during their larval/nymphal stage.Fatty acid profiles of diets and insects were determined via GC‐MS.The three species had distinct fatty acid profiles on all four diets,but responded similarly to flaxseed oil addition.For each percent added to the diet,the alpha‐linolenic acid content of the insects increased by 2.3%–2.7%.Four percent addition increased the n‐3 fatty acid content 10–20 fold in the three species and thereby strongly decreased n‐6/n‐3 ratios from 18–36 to 0.8–2.4.A ratio below 5 is considered optimal for human health and was achieved by 2%flaxseed oil inclusion for house crickets and lesser mealworms,and at 1%inclusion for black soldier flies.Adding a source of n‐3 fatty acids to insect diets can thus improve the nutritional quality of insects.展开更多
Myotonic dystrophy-related Cdc42-binding kinase alpha(MRCKα)is an integral component of signaling pathways controlling vital cellular processes,including cytoskeletal reorganization,cell proliferation and cell surviv...Myotonic dystrophy-related Cdc42-binding kinase alpha(MRCKα)is an integral component of signaling pathways controlling vital cellular processes,including cytoskeletal reorganization,cell proliferation and cell survival.In this study,we investigated the physiological role of MRCKα in milk protein and fat production in dairy cows,which requires a dynamic and strict organization of the cytoskeletal network in bovine mammary epithelial cells(BMEC).Within a selection of 9 Holstein cows,we found that both mRNA and protein expression of MRCKα in the mammary gland were upregulated during lactation and correlated positively(r>0.89)with the mRNA and protein levels of b-casein.Similar positive correlations(r>0.79)were found in a primary culture of BMEC stimulated with prolactin for 24 h.In these cells,silencing of MRCKα decreased basal b-casein,sterol-regulatory element binding protein(SREBP)-1 and cyclin D1 protein level,phosphorylation of mTOR,triglyceride secretion,cell number and viabilitydwhile overexpression of MRCKα displayed the reversed effect.Notably,silencing of MRCKα completely prevented the stimulatory action of prolactin on the same parameters.These data demonstrate that MRCKα is a critical mediator of prolactin-induced lactogenesis via stimulation of the mTOR/SREBP1/cyclin D1 signaling pathway.展开更多
Whereas the use of probiotics is commonplace in commercial production of improved chicken strains,little is known about the impact of these live microbial feed additives in indigenous chickens in South Africa. This st...Whereas the use of probiotics is commonplace in commercial production of improved chicken strains,little is known about the impact of these live microbial feed additives in indigenous chickens in South Africa. This study investigated the effect of a multi-strain probiotic(containing Bacillus safensis, Bacillus subtilis, Bacillus megaterium and Cupriavidus metallidurans, total bacteria number was 1.4 × 10~8 cfu/mL),administered via drinking water, on growth performance, blood parameters, and carcass and meat quality characteristics of Potchefstroom koekoek cockerels for a period of 12 weeks. A total of 140 fiveweek-old cockerels were randomly allocated to 4 experimental diets formulated to have similar energy and protein levels as follows: 1) negative control diet(CON;commercial chicken grower diet without both antibiotics and probiotics), 2) positive control diet(ANTIB;commercial chicken grower diet with antibiotics [0.05% Coxistac and 0.04% olaquindox] but no probiotics), 3) negative control diet plus 2.5 mL of probiotics per litre of water(PROB25) and 4) negative control with 5.0 mL of probiotics per litre of water(PROB50). There was a significant(P < 0.05) week and diet interaction effect on average weekly feed conversion efficiency. At 9 weeks of age, cockerels in PROB50 group had higher(P < 0.05) feed conversion efficiency than those in CON and ANTIB groups. However, 14-week-old cockerels in PROB50 group had lower(P < 0.05) feed conversion efficiency than those in ANTIB group. Treatments had no significant(P > 0.05) effect on overall feed intake, overall weight gain and haemato-biochemical parameters of cockerels. Gizzard and spleen weights were similar(P > 0.05) in PROB50, CON and PROB25 groups. Cockerels in PROB50 group had shorter(P < 0.05) small intestine than those in CON and PROB25 groups. Cockerels in PROB50 group had larger(P < 0.05) breast weight than those in PROB25 group.Cockerels in ANTIB and PROB50 groups had greater(P < 0.05) wing and thigh weights than those in CON and PROB25 groups. Shank weight was similar(P > 0.05) in PROB50, CON and ANTIB groups. Meat pH measured after 24 h of slaughter was the highest(P < 0.05) in CON and ANTIB groups followed by PROBO25 and PROB50 groups. Cockerels in CON group had lower(P < 0.05) cooking losses than those in ANTIB, PROB25 and PROB50 groups. It was concluded that probiotics can be used in place of prophylactic antibiotics in Potchefstroom koekoek cockerels.展开更多
The effects of replacing grass silage by sainfoin silage in a total mixed ration(TMR)based diet on fatty acid(FA)reticular inflow and milk FA profile of dairy cows was investigated.The experiment followed a crossover ...The effects of replacing grass silage by sainfoin silage in a total mixed ration(TMR)based diet on fatty acid(FA)reticular inflow and milk FA profile of dairy cows was investigated.The experiment followed a crossover design with 2 dietary treatments.The control diet consisted of grass silage,corn silage,concentrate and linseed.In the sainfoin diet,half of the grass silage was replaced by a sainfoin silage.Six rumen cannulated lactating multiparous dairy cows with a metabolic body weight of 132.5±3.6 kg BW^0.75,214±72 d in milk and an average milk production of 23.1±2.8 kg/d were used in the experiment.Cows were paired based on parity and milk production.Within pairs,cows were randomly assigned to either the control diet or the sainfoin diet for 2 experimental periods(29 d per period).In each period,the first 21 d,cows were housed individually in tie-stalls for adaptation,then next 4 d cows were housed individually in climate-controlled respiration chambers to measure CH4.During the last 4 d,cows were housed individually in tie stalls to measure milk FA profile and determine FA reticular inflow using the reticular sampling technique with Cr-ethylenediaminetetraacetic acid disodium salt dihydrate(EDTA)and Yb-acetate used as digesta flow markers.Although the dietary C18:3n-3 intake was lower(P=0.025)in the sainfoin diet group,the mono-unsaturated FA reticular inflow was greater(P=0.042)in cows fed the sainfoin diet.The reticular inflow of trans-9,trans-12-C18:2 and cis-12,trans-10 C18:2 was greater(P≤0.024)in the sainfoin diet group.The cows fed sainfoin diet had a lower(P≤0.038)apparent ruminal biohydrogenation of cis-9-C18:1 and C18:3n-3,compared to the cows fed the control diet.The sainfoin diet group had greater(P≤0.018)C18:3n-3 and cis-9,cis-12-C18:2 proportions in the milk FA profile compared to the control diet group.Transfer efficiencies from feed to milk of C18:2,C18:3n-3 and unsaturated FA were greater(P≤0.0179)for the sainfoin diet.Based on the results,it could be concluded that replacing grass silage by sainfoin silage in dairy cow rations reduces ruminal C18:3n-3 biohydrogenation and improves milk FA profile.展开更多
基金financed by the Topsector Agri&Food and Agrifirm as coordinated by the Dutch Carbohydrate Competence Centre(CCC-ABCwww.cccresearch.nl)
文摘Background: Starch is the main source of energy in commonly used pig diets.Besides effects related to the extent of starch digestion,also several effects related to variation in digestion rate have recently been demonstrated in non-ruminants.Different rates of starch digestion in animals and in in vitro models have been reported,depending on the botanic origin of starch.Starches from different botanic sources differ widely in structural and molecular properties.Predicting the effect of starch properties on in vitro digestion kinetics based on existing literature is hampered by incomplete characterization of the starches,or by a selective choice of starches from a limited number of botanic sources.This research aimed to analyse the relationships between starch properties and in vitro digestion kinetics of pure starches isolated from a broad range of botanic origins,which are used in non-ruminant diets or have a potential to be used in the future.Therefore we studied starch digestion kinetics of potato,pea,corn,rice,barley,and wheat starches,and analysed the granule diameter,number of pores,type and amount of crystalline structure,amylose content and amylopectin side-chain length of all starches.Results: Multivariate analysis revealed strong correlations among starch properties,leading us to conclude that effects of most starch characteristics are strongly interrelated.Across all analysed botanic sources,crystalline type and amylopectin chain length showed the strongest correlation with in vitro digestion kinetics.Increased percentages of A–type crystalline structure and amylopectin side chains of DP 6–24 both increased the rate of digestion.In addition,within,but not across,(clusters of) botanic sources,a decrease in amylose content and increase in number of pores correlated positively with digestion kinetics.Conclusion: The type of crystalline structure and amylopectin chain length distribution of starch correlate significantly with digestion kinetics of starches across botanic sources in an in vitro pig model.Variation in digestion kinetics across botanic sources is not additively explained by other starch properties measured,but appears to be confined within botanical sources.
基金funded by Dutch Technology Foundation(STW),which is part of the Netherlands Organization for Scientific Research(NWO)partially funded by the Spanish projects AGL2011-25379,AGL2014-53730-R and CTQ2014-60764-JIN(co-financed by FEDER funds)+1 种基金the CSIC project 2014-40E-097the EU-project INDOX(KBBE-2013-7-613549)
文摘Background: The present work investigated the influence of lignin content and composition in the fungal treatment of lignocellulosic biomass in order to improve rumen degradability. Wheat straw and wood chips,differing in lignin composition, were treated with Lentinula edodes for 0, 2, 4, 8 and 12 wk and the changes occurring during fungal degradation were analyzed using pyrolysis-gas chromatography-mass spectrometry and detergent fiber analysis.Results: L. edodes preferentially degraded lignin, with only limited cellulose degradation, in wheat straw and wood chips, leaving a substrate enriched in cellulose. Syringyl(S)-lignin units were preferentially degraded than guaiacyl(G)-lignin units, resulting in a decreased S/G ratio. A decreasing S/G ratio(wheat straw: r =-0.72, wood chips: r =-0.75) and selective lignin degradation(wheat straw: r =-0.69, wood chips: r =-0.88) were correlated with in vitro gas production(IVGP), a good indicator for rumen degradability.Conclusions: L. edodes treatment increased the IVGP of wheat straw and wood chips. Effects on IVGP were similar for wheat straw and wood chips indicating that lignin content and 3D-structure of cell walls influence in vitro rumen degradability more than lignin composition.
基金supported by the Dutch Technology Foundation (STW)which is part of the Netherlands Organization for Scientific Research (NWO)+1 种基金which is partly funded by the Dutch Ministry of Economic Affairsproject (11611) was co-sponsored by Agrifirm, Purac, DSM, Den Ouden, Hofmans, the Dutch commodity boards for dairy and horticulture, and Wageningen University
文摘Background: The aim of this study was to optimize the fungal treatment of lignocellulosic biomass by stimulating the colonization. Wheat straw and wood chips were treated with Ceriporiopsis subvermispora and Lentinula edodes with various amounts of colonized millet grains(0.5, 1.5 or 3.0 % per g of wet weight of substrate) added to the substrates. Also, wheat straw and wood chips were chopped to either 0.5 or 2 cm.Effectiveness of the fungal treatment after 0, 2, 4, 6, or 8 wk of incubation was determined by changes in chemical composition, in vitro gas production(IVGP) as a measure for rumen degradability, and ergosterol content as a measure of fungal biomass.Results: Incomplete colonization was observed for C. subvermispora treated wheat straw and L. edodes treated wood chips. The different particle sizes and amounts of inoculum tested, had no significant effects on the chemical composition and the IVGP of C. subvermispora treated wood chips. Particle size did influence L.edodes treatment of wheat straw. The L. edodes treatment of 2 cm wheat straw resulted in a more selective delignification and a higher IVGP than the smaller particles. Addition of 1.5 % or 3 % L. edodes inoculum to wheat straw resulted in more selective delignification and a higher IVGP than addition of 0.5 % inoculum.Conclusion: Particle size and amount of inoculum did not have an effect on C. subvermispora treatment of wood chips. At least 1.5 % L. edodes colonized millet grains should be added to 2 cm wheat straw to result in an increased IVGP and acid detergent lignin(ADL) degradation.
基金conducted by Wageningen University and Research(Wageningen Livestock Research, Wageningen, the Netherlands)commissioned and funded by the Ministry of Agriculture+2 种基金Nature and Food Quality (The Hague, the Netherlands) within the framework of Policy Support Research theme ‘Feed4 Foodure’(BO-31.03-005-001TKI-AF12039)by the Vereniging Diervoederonderzoek Nederland (Rijswijk, the Netherlands)。
文摘Background: Characterising the regulation of milk component synthesis in response to macronutrient supply is critical for understanding the implications of nutritional interventions on milk production. Gene expression in mammary gland secretory cells was measured using RNA isolated from milk fat globules from 6 Holstein-Friesian cows receiving 5-d abomasal infusions of saline, essential amino acids(AA), or glucose(GG) or palm olein(LG)without(LAA) or with(HAA) essential AA, according to a 6 × 6 Latin square design. RNA was isolated from milk fat samples collected on d 5 of infusion and subjected to real-time quantitative PCR. We hypothesised that m RNA expression of genes involved in de novo milk fatty acid(FA) synthesis would be differently affected by GG and LG,and that expression of genes regulating transfer of tricarboxylic acid cycle intermediates would increase at the HAA level. We also hypothesised that the HAA level would affect genes regulating endoplasmic reticulum(ER)homeostasis but would not affect genes related to the mechanistic target of rapamycin complex 1(m TORC1) or the integrated stress response(ISR) network.Results: Infusion of GG did not affect de novo milk FA yield but decreased expression of FA synthase(FASN).Infusion of LG decreased de novo FA yield and tended to decrease expression of acetyl-Co A carboxylase 1(ACC1).The HAA level increased both de novo FA yield and expression of ACC1, and tended to decrease expression of mitochondrial phosphoenolpyruvate carboxykinase(PCK2). m RNA expression of m TORC1 signaling participants was not affected by GG, LG, or AA level. Expression of the ε subunit of the ISR constituent eukaryotic translation initiation factor 2 B(EIF2 B5) tended to increase at the HAA level, but only in the presence of LG. X-box binding protein 1(XBP1) m RNA was activated in response to LG and the HAA level.Conclusions: Results show that expression of genes involved in de novo FA synthesis responded to glucogenic,lipogenic, and aminogenic substrates, whereas genes regulating intermediate flux through the tricarboxylic acid cycle were not majorly affected. Results also suggest that after 5 d of AA supplementation, milk protein synthesis is supported by enhanced ER biogenesis instead of signaling through the mTORC1 or ISR networks.
基金the financial support from the Wageningen UR“IPOP Customized Nutrition”programme financed by Wageningen UR,the Dutch Ministry of Economic Affairs,WIAS,Agrifirm Innovation Center,ORFFA Additives BV,Ajinomoto Eurolysine s.a.s and Stichting VICTAM BV.SSV acknowledgesthe support from the Universidad de Costa Rica
文摘Background: Toasting during the production of rapeseed meal(RSM) decreases ileal crude protein(CP) and amino acid(AA) digestibility. The mechanisms that determine the decrease in digestibility have not been fully elucidated. A high protein quality, low-denatured, RSM was produced and toasted up to 120 min, with samples taken every 20 min. The aim of this study was to characterize secondary structure and chemical changes of proteins and glucosinolates occurring during toasting of RSM and the effects on its in vitro CP digestibility.Results: The decrease in protein solubility and the increase of intermolecular β-sheets with increasing toasting time were indications of protein aggregation. The contents of NDF and ADIN increased with increasing toasting time.Contents of arginine, lysine and O-methylisourea reactive lysine(OMIU-RL) linearly decreased with increasing toasting time, with a larger decrease of OMIU-RL than lysine. First-order reactions calculated from the measured parameters show that glucosinolates were degraded faster than lysine, OMIU-RL and arginine and that physical changes to proteins seem to occur before chemical changes during toasting. Despite the drastic physical and chemical changes noticed on the proteins, the coefficient of in vitro CP digestibility ranged from 0.776 to 0.750 and there were no effects on the extent of protein hydrolysis after 120 min. In contrast, the rate of protein hydrolysis linearly decreased with increasing toasting time, which was largely correlated to the decrease in protein solubility, lysine and OMIU-RL observed. Rate of protein hydrolysis was more than 2-fold higher for the untoasted RSM compared to the 120 min toasted material.Conclusions: Increasing the toasting time for the production of RSM causes physical and chemical changes to the proteins that decrease the rate of protein hydrolysis. The observed decrease in the rate of protein hydrolysis could impact protein digestion and utilization.
文摘Edible insects are advocated as sustainable and healthy food and feed.However,commercially produced insects are often low in n‐3 fatty acids and have suboptimal n‐6/n‐3 ratios.A certain amount and proportion of these FAs is required to optimize human health.Flaxseed oil consists primarily(57%)out of alpha‐linolenic acid.An experiment was conducted to quantify the effect of flaxseed oil provision on fatty acid composition and to determine the quantity needed to attain a beneficial n‐6/n‐3 ratio.Three species were used in the experiment:house crickets(Acheta domesticus[L.]),lesser mealworms(Alphitobius diaperinus[Pfanzer])and black soldier flies(Hermetia illucens[L.]).These were provided with either a control diet or a diet enriched with 1%,2%,or 4%flaxseed oil during their larval/nymphal stage.Fatty acid profiles of diets and insects were determined via GC‐MS.The three species had distinct fatty acid profiles on all four diets,but responded similarly to flaxseed oil addition.For each percent added to the diet,the alpha‐linolenic acid content of the insects increased by 2.3%–2.7%.Four percent addition increased the n‐3 fatty acid content 10–20 fold in the three species and thereby strongly decreased n‐6/n‐3 ratios from 18–36 to 0.8–2.4.A ratio below 5 is considered optimal for human health and was achieved by 2%flaxseed oil inclusion for house crickets and lesser mealworms,and at 1%inclusion for black soldier flies.Adding a source of n‐3 fatty acids to insect diets can thus improve the nutritional quality of insects.
基金the Natural Science Foundation of China,China(31872383)the Key Research and Development Program of the Ningxia Hui Autonomous Region,China(2021BEF02018)+1 种基金the Scientific Research Project for Major Achievements of the Agricultural Science and Technology Innovation Program(ASTIP)of Chinese Academy of Agricultural Sciences,China(ASTIP-IAS07-1,CAAS-XTCX2016011-01)International Atomic Energy Agency Technical Co-Operation and Assistance Programme,China(no.CPR5025).
文摘Myotonic dystrophy-related Cdc42-binding kinase alpha(MRCKα)is an integral component of signaling pathways controlling vital cellular processes,including cytoskeletal reorganization,cell proliferation and cell survival.In this study,we investigated the physiological role of MRCKα in milk protein and fat production in dairy cows,which requires a dynamic and strict organization of the cytoskeletal network in bovine mammary epithelial cells(BMEC).Within a selection of 9 Holstein cows,we found that both mRNA and protein expression of MRCKα in the mammary gland were upregulated during lactation and correlated positively(r>0.89)with the mRNA and protein levels of b-casein.Similar positive correlations(r>0.79)were found in a primary culture of BMEC stimulated with prolactin for 24 h.In these cells,silencing of MRCKα decreased basal b-casein,sterol-regulatory element binding protein(SREBP)-1 and cyclin D1 protein level,phosphorylation of mTOR,triglyceride secretion,cell number and viabilitydwhile overexpression of MRCKα displayed the reversed effect.Notably,silencing of MRCKα completely prevented the stimulatory action of prolactin on the same parameters.These data demonstrate that MRCKα is a critical mediator of prolactin-induced lactogenesis via stimulation of the mTOR/SREBP1/cyclin D1 signaling pathway.
基金The financial assistance from the Organization for Women in Science for Developing World (OWSD)and the Carnegie Cooperation of New York through the Regional Universities Forum for Capacity Building in Agriculture(RUFORUM)
文摘Whereas the use of probiotics is commonplace in commercial production of improved chicken strains,little is known about the impact of these live microbial feed additives in indigenous chickens in South Africa. This study investigated the effect of a multi-strain probiotic(containing Bacillus safensis, Bacillus subtilis, Bacillus megaterium and Cupriavidus metallidurans, total bacteria number was 1.4 × 10~8 cfu/mL),administered via drinking water, on growth performance, blood parameters, and carcass and meat quality characteristics of Potchefstroom koekoek cockerels for a period of 12 weeks. A total of 140 fiveweek-old cockerels were randomly allocated to 4 experimental diets formulated to have similar energy and protein levels as follows: 1) negative control diet(CON;commercial chicken grower diet without both antibiotics and probiotics), 2) positive control diet(ANTIB;commercial chicken grower diet with antibiotics [0.05% Coxistac and 0.04% olaquindox] but no probiotics), 3) negative control diet plus 2.5 mL of probiotics per litre of water(PROB25) and 4) negative control with 5.0 mL of probiotics per litre of water(PROB50). There was a significant(P < 0.05) week and diet interaction effect on average weekly feed conversion efficiency. At 9 weeks of age, cockerels in PROB50 group had higher(P < 0.05) feed conversion efficiency than those in CON and ANTIB groups. However, 14-week-old cockerels in PROB50 group had lower(P < 0.05) feed conversion efficiency than those in ANTIB group. Treatments had no significant(P > 0.05) effect on overall feed intake, overall weight gain and haemato-biochemical parameters of cockerels. Gizzard and spleen weights were similar(P > 0.05) in PROB50, CON and PROB25 groups. Cockerels in PROB50 group had shorter(P < 0.05) small intestine than those in CON and PROB25 groups. Cockerels in PROB50 group had larger(P < 0.05) breast weight than those in PROB25 group.Cockerels in ANTIB and PROB50 groups had greater(P < 0.05) wing and thigh weights than those in CON and PROB25 groups. Shank weight was similar(P > 0.05) in PROB50, CON and ANTIB groups. Meat pH measured after 24 h of slaughter was the highest(P < 0.05) in CON and ANTIB groups followed by PROBO25 and PROB50 groups. Cockerels in CON group had lower(P < 0.05) cooking losses than those in ANTIB, PROB25 and PROB50 groups. It was concluded that probiotics can be used in place of prophylactic antibiotics in Potchefstroom koekoek cockerels.
基金financially supported by the European Commission Marie Curie Research Training Network grant“LegumePlus”(PITN-GA-2011-289377)
文摘The effects of replacing grass silage by sainfoin silage in a total mixed ration(TMR)based diet on fatty acid(FA)reticular inflow and milk FA profile of dairy cows was investigated.The experiment followed a crossover design with 2 dietary treatments.The control diet consisted of grass silage,corn silage,concentrate and linseed.In the sainfoin diet,half of the grass silage was replaced by a sainfoin silage.Six rumen cannulated lactating multiparous dairy cows with a metabolic body weight of 132.5±3.6 kg BW^0.75,214±72 d in milk and an average milk production of 23.1±2.8 kg/d were used in the experiment.Cows were paired based on parity and milk production.Within pairs,cows were randomly assigned to either the control diet or the sainfoin diet for 2 experimental periods(29 d per period).In each period,the first 21 d,cows were housed individually in tie-stalls for adaptation,then next 4 d cows were housed individually in climate-controlled respiration chambers to measure CH4.During the last 4 d,cows were housed individually in tie stalls to measure milk FA profile and determine FA reticular inflow using the reticular sampling technique with Cr-ethylenediaminetetraacetic acid disodium salt dihydrate(EDTA)and Yb-acetate used as digesta flow markers.Although the dietary C18:3n-3 intake was lower(P=0.025)in the sainfoin diet group,the mono-unsaturated FA reticular inflow was greater(P=0.042)in cows fed the sainfoin diet.The reticular inflow of trans-9,trans-12-C18:2 and cis-12,trans-10 C18:2 was greater(P≤0.024)in the sainfoin diet group.The cows fed sainfoin diet had a lower(P≤0.038)apparent ruminal biohydrogenation of cis-9-C18:1 and C18:3n-3,compared to the cows fed the control diet.The sainfoin diet group had greater(P≤0.018)C18:3n-3 and cis-9,cis-12-C18:2 proportions in the milk FA profile compared to the control diet group.Transfer efficiencies from feed to milk of C18:2,C18:3n-3 and unsaturated FA were greater(P≤0.0179)for the sainfoin diet.Based on the results,it could be concluded that replacing grass silage by sainfoin silage in dairy cow rations reduces ruminal C18:3n-3 biohydrogenation and improves milk FA profile.