Germination Characteristics of Halogeton glomeratus under Different Heavy Metals Treatments with NaCl Stress北大核心CSCD

This study firstly researched germination characteristics of Halogeton glomeratus under different concentrations of heavy metals Cu2+,Zn2+,Ni2+,Cd2+ and Pb2+ supplemented with 100 mmol·L-1 NaCl. The results showed that germination rate and germination potential increased at first and then decreased with the increase of the heavy metals concentrations. It indicated that the low concentration of heavy metal ions promoted the germination of plants. Fresh weight,dry weight and seedlings height decreased gradually. The results of ion contents showed that Cd2+ and Pb2+ contents increased at first and then decreased,and Cu2+,Zn2+ and Ni2+ contents increased with increasing heavy metals concentrations. The root activity of Cu2+ and Zn2+ increased first and then decreased,and it decreased with the increase of Ni2+,Cd2+ and Pb2+ concentrations. The comprehensive clustering and principal component analysis were carried out to obtain the critical concentrations of Cu2+,Zn2+,Ni2+,Cd2+ and Pb2+ in Halogeton glomeratus,which were 1.00 mmol·L-1,10.00 mmol·L-1,0.30 mmol·L-1,0.20 mmol·L-1 and 0.50 mmol·L-1,respectively. The most important indexes were germination index,dry weight,germination energy,dry weight and germination energy when the stress concentration reached the critical value for Halogeton glomeratus. © 2019 Ｊｏｕｒｎａｌ ｏｆ Ｒｅｆｒｉｇｅｒａｔｉｏｎ. All rights reserved.     

Physiological ecological and secondary metabolic responses of the herbaceous resource plant Thlaspi arvense to salt stress北大核心CSCD

This research explored the physiological and ecological responses and secondary metabolites of Thlaspi arvense （pennycress） under salt stress in order to develop a theoretical foundation for further research on the planting of salt-tolerant plants on saline-alkali soils. Hydroponically cultured pennycress was grown at 5 NaCl concentrations （0,50,100,150,200 mmol·L−1） set to simulate a gradient of salt stress intensity. Leaves of pennycress were collected at 1,5,10,and 15 days to determine physiological and biochemical indexes,photosynthetic parameters and secondary metabolite levels. It was found that： 1） The activities of superoxide dismutase,peroxidase,and catalase in the leaves of T. arvense showed a pattern of initial increase and then decrease with increase in salt concentration during the period of salt stress. 2） The enzyme activity was highest at the NaCl concentration of 100 mmol·L−1. 3） Levels of malondialdehyde first increased and then decreased with increase in salt concentration. 4） The contents of soluble sugar and proline in the leaves of T. arvense increased with increase in salt concentration and with the length of exposure to NaCl stress,while soluble protein levels first increased and then decreased with increase in salt concentration. 5） The chlorophyll a, chlorophyll b, total chlorophyll content, chlorophyll fluorescence parameters,net photosynthetic rate and transpiration rates in T. arvense leaves showed a downward trend with increase in salt concentration,and the decline gradually increased. 6） The contents of total flavonoids,total phenols,and sinigrin in the leaves of T. arvense showed a pattern of initial increase and then decreasing with increase in salt concentration. Thus,pennycress has a high tolerance to salt stress and can maintain normal growth in a salt-stress environment of 50-100 mmol·L−1 NaCl concentration. This result provides a theoretical basis for future research on the salt tolerance mechanisms of T. arvense and other natrophilic plants. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

Effects of Exogenous Glycine Betaine on the Physiological Characteristics in Medicago sativa Seedlings under Low-temperature Stress北大核心CSCD

In this study,the 'Ganong 5th' alfalfa (Medicago sativa L.) was used as experimental material,and two application methods (leaf application,root application) and six exogenous betaine concentrations (0,10,20,30,40 and 50 mmol·L-1) were used to treat the seedlings of alfalfa. Plant growth and related physiological indexes were measured after 7 days of low temperature (4?) stress,and the physiological mechanism of exogenous betaine to alleviate the low temperature stress of alfalfa was explored. The results showed that exogenous GB alleviated the loss of plant height,root length,leaf dry weight,root dry weight and chlorophyll content,and increase the content of soluble sugar (SS) and free proline (Pro),and reduced the increase in leaf relative membrane permeability and MDA content. Exogenous GB increased antioxidant enzyme activities and non-enzymatic antioxidant content. And also,exogenous GB enhanced the osmotic adjustment capacity of the plant by increasing endogenous GB accumulation and BADH activity. These results indicated that exogenous GB enhanced the resistance of Medicago sativa to low-temperature stress under low temperature adjustment. The membership function analysis indicated that spraying 30 mmol·L-1 GB on the leaves and spraying 40 mmol·L-1 GB on the roots had the best effect on alleviating the low-temperature stress of alfalfa seedlings. © 2019 Ｊｏｕｒｎａｌ ｏｆ Ｒｅｆｒｉｇｅｒａｔｉｏｎ. All rights reserved.     

Physiological effects of different Cd concentrations on maize root architecture and classification北大核心CSCD

In this research, a hydroponics experiment was conducted to apply different concentrations of cadmium (Cd) (0, 5, 10, 25, 50, 100, 200 μmol·L-1) to maize seedlings with two leaves and one new leaf, in order to explore the effects of the different Cd concentrations on the maize seedling growth, Cd absorption kinetics and root morphology and classification. After 5 days of Cd stress, the maize seedings were sampled, the plant height, main root length, aboveground and underground biomass, root architecture, Cd content and photosynthesis and related parameters were measured. It was found that with increasing Cd stress, the plant height, main root length, biomass and tolerance index of shoots and roots, total root length, root surface area, root volume, root forks and root tips all decreased significantly; Root average diameter and root:shoot increased significantly (P<0.05). Meanwhile root parameters (root length, root surface area and root volume) of root diameter classes designated Ⅰ-Ⅲ (0-1.5 mm) showed a decreasing trend, which had a significant (P<0.05) negative correlation with root Cd concentration. The proportion of root length, root surface area and root volume with diameter between 0-0.5 mm showed a downward trend under Cd stress. Under Cd stress, Cd concentration and accumulation in underground and aboveground parts of maize seedlings increased significantly, chlorophyll content decreased, and photosynthesis was inhibited. This study has shown that Cd affected root development mainly by inhibiting the growth and morphology of fine roots, and inhibited photosynthesis, elongation and biomass accumulation of the aboveground and underground parts of the maize seedings. © 2022, Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

The Effect of Irrigation Period and Amount on Production Performance of Alfalfa in Haihe Plain北大核心CSCD

To explore the suitable irrigation techniques for Alfalfa in Haihe Plain, six irrigation treatments were set up to study the effects of different irrigation treatments on the yield, agronomic traits and water use efficiency of one-year and two-year Alfalfa from 2015 to 2017. The results showed that alfalfa yield increased slightly with increasing irrigation amount in Haihe Plain, but had no significant difference among six treatments. Compared with the treatment without irrigation, the cumulative increment of alfalfa yield in three years was only 6. 13 t • hm~z. The water use efficiency of Alfalfa significantly decreased gradually with the increase of irrigation amount (P相似文献   

Maternal body condition during late-pregnancy is associated with in utero development and neonatal growth of Holstein calves

Background: Nutritional management in the dry period can alter body condition score(BCS) in dairy cows, a subjective measure of body fat. As such, differences in BCS during late-pregnancy not only mirror nutrient utilization by fat depots, but also can play important roles on the metabolic and hormonal environment. We investigated the association between cow BCS during late-pregnancy on developmental parameters and blood variables of neonatal calves. Forty-nine multiparous Holstein cows were retrospectively divided by prepartal BCS into normal BCS ≤3.25(NormBCS; 3.02 ± 0.17, n = 30) or high BCS ≥3.75(HighBCS; 3.83 ± 0.15, n = 19) groups.Plasma samples were collected from cows at-10 d relative to parturition. Body weight, hip and wither height, hip width and body length were measured at birth and weekly through weaning(42 d of age) and until 9 weeks of age. Calf blood samples were collected from the jugular vein at birth(before receiving colostrum, 0 d), 24 h after first colostrum and at 7, 21, 42 and 50 d of age. The data were subjected to ANOVA using the mixed procedure of SAS. The statistical model included day, BCS, and their interactions.Results: Dry matter intake(kg/d or % of body weight) during the last 4 weeks of pregnancy was lower(P ≤ 0.06) in HighBCS cows. Plasma concentrations of fatty acids, ceruloplasmin, and nitric oxide were greater overall(P 0.05) at d-10 prior to calving in HighBCS cows, and they tended(P = 0.08) to have greater concentrations of reactive oxygen metabolites. Birth body weight was lower(P = 0.03) in calves born to dams with HighBCS. In addition,plasma concentrations of fatty acids, albumin and urea(P 0.05) were greater in those calves. Although calves born to cows with HighBCS maintained a lower postnatal body weight(P = 0.04), hip and wither height, hip width, and body length, there was no difference(P 0.05) in daily starter intake and average daily gain due to maternal BCS.Conclusions: Overall, results highlight an association between BCS during late-gestation on in utero calf development and postnatal growth. A high maternal BCS during late-gestation was associated with lower calf body weights, which could be due to lower maternal intakes and a state of inflammation and metabolic stress.     

The influences of reseeding date and mowing prior to reseeding on establishment of alfalfa in Leymus chinensis meadows北大核心CSCD

This research studied the effects of sowing date and cutting prior to sowing on establishment of the leguminous forage，alfalfa（Medicago sativa），in a lightly degraded Leymus chinensis meadow and investigated the sowing date×cutting interaction. The factorial experiment comprised four sowing dates（May 1，June 1，July 1，August 1）and cutting treatment（cut or uncut）prior to sowing，and evaluated the establishment performance of alfalfa and the ecological mechanisms related to establishment. It was found that soil moisture during emergence of alfalfa was the greatest when sowing occurred on July 1，and clipping prior to sowing significantly decreased the plant height of L. chinensis during emergence and seedling growth of alfalfa. There was a significant sowing date×cutting interaction effect on alfalfa establishment. Clipping prior to sowing significantly increased the emergence percentage of alfalfa through reducing the plant height of L. chinensis and associated above-and below-ground competition，and the seasonal soil moisture change resulted in a 20% higher（P<0. 05）alfalfa emergence rate when sowing occurred on July 1. With cutting，the number of surviving alfalfa seedlings and seedling survival rate were greatest（83 plants· m−2 and 53%，respectively）when sowing occurred on July 1. For later sowing，owing to the shortened growing time，the development and overwintering survival rates of alfalfa seedlings were significantly reduced. Cutting prior to sowing significantly increased the overwintering rate of alfalfa seedlings through improving their development. In the cutting treatment，the number of overwintered alfalfa seedlings（22 plants·m−2）when sowing was on July 1 was significantly higher than for other reseeding dates. In the second year，a botanical composition measurement showed that clipping prior to reseeding significantly increased the alfalfa biomass within the meadow，and the alfalfa biomass was significantly greater than in other treatments when sowing occurred on July 1 after cutting. Cutting prior to sowing also significantly increased the crude protein content of forage. Based on these research results，normal production practice should include cutting when alfalfa is sown into L. chinensis meadow. Combined with cutting，a sowing date around July 1 is the most favorable for the establishment of alfalfa. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

Progress on the taxonomic classification of Medicago species北大核心CSCD

This review investigates the disordered status of the classification of Medicago genus,both domestically and internationally. Several definitions of a taxonomic species were considered and the names and characteristics of 13 Medicago species in China are reported,together with a detailed summary of the names,life forms,chromosome numbers,pollination methods and natural distribution of about 90 Medicago species worldwide,including the classification of 14 sections and 10 subsections in Medicago. The molecular evolutionary relationships between different species,and the geographical origin of Medicago are discussed,and the genetic relationships between different subspecies in the alfalfa complex are further explained. This study puts forward a method of identifying Medicago species on the basis of deep understanding of the concept of species. A wide collection of global Medicago germplasm resources,aiming to further clarify the evolutionary relationship among different sections and different species by molecular evolution methods is proposed. This review provides a reference framework for future Medicago classification and alfalfa cross breeding. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

Evaluation of nutritive value and in vitro rumen fermentation gas accumulation of de-oiled algal residues

Background：Algae are widely recognized for their high oil content and for exponentially accumulating biomass with particular potential to provide single cell protein for human consumption or animal feed.It is believed that along with biodiesel from algae,the high protein de-oiled algal residue may become an alternative feed supplement option in the future.This study was conducted to investigate de-oiled algal residue obtained from the common Chlorella species,Thalassiosira weissflogii,Selenarstrum capricornutum,Scenedesmus sp.,and Scenedesmus dimorphus for assessment as potential feed supplements for ruminants by comparing with soybean（Glycine max） meal and alfalfa（Medicago sativa） hay.Results：With the exception of T.weissflogii,algal residue had higher concentrations of Cu,Zn,and Mn and lower concentration of Ca,Mg,and K than soybean meal and alfalfa hay.The algal residue CP（crude protein）concentrations ranged from 140 to 445 g/kg DM and varied among the de-oiled residues.In vitro rumen fermentation gas accumulation curves indicated that algal biomass degradation potential was less than that of soybean meal or alfalfa hay by up to 41.7%.The gas production curve,interpreted with a dual pool logistic model,confirmed that the fraction sizes for fast fermenting and slow fermenting of de-oiled algal residues were smaller than those in soybean meal and alfalfa hay,and the fermenting rate of the fractions was also low.Conclusions：Inferior in vitro rumen gas accumulation from the five de-oiled algal residues suggests that these algal byproducts are less degradable in the rumen.     

Correlation Analysis for Feeding Habits,Morphological Parameters,Weight Parameters and Abdomen Meat Percentage of Procambarus clarkii北大核心CSCD

This experiment was conducted to determine the food source and trophic level of Procambarus clarkii from rice-crayfish field by stable isotope method, and to analyze the correlation between feeding habits, morphology parameters, weight parameters and abdomen meat percentage of P. clarkii. normal (62 individuals) and claw reborned (6 individuals) samples of P. clarkii were collected from the rice-crayfish continuous production field in Zhanjiang. At the same time, vascular plants, snails, as well as diet samples were collected. The stable carbon and nitrogen isotope values of all collected samples were analyzed, the contribution rate of diet, Elodea nuttallii and Potamogeton crispus to the abdomen meat growth of P. clarkii were calculated using a stable isotope mixing model including element concentration, and the trophic levels of P. clarkii and Pomacea canaliculata were calculated by stable nitrogen isotope model. The correlation between stable carbon and nitrogen isotope characteristics (δ13 C and δ15 N) of abdomen meat, morphological parameters (body length, full length, carapace length, carapace width, tail fan length) and weight parameters (body weight, abdomen meat weight, claw weight, claw body ratio) of the collected crayfish were analyzed. The results showed as follows: 1) the collected crayfish included 30 female and 32 male individuals, and the body weight of these crayfish ranged from 3.40 to 29.35 g, average (14.05±6.26) g. The model calculation results showed that diet contributed 63.40% of biomass, 62.28% of carbon and 75.15% of nitrogen to the abdomen meat growth of P. clarkii. 2) In this study, Cipangopaludina cahayensis was used as the baseline for primary consumers, and the calculated trophic level of P. clarkii was 2.20, while the trophic level of P. canaliculata was 2.68. 3) The abdomen meat percentage of P. clarkii (<15 g) collected were extremely negatively correlated with the claw weight and the claw body ratio (P<0.01), indicated that the growth of the claws directly affected the muscle growth of these crayfish. The abdomen meat percentage of P. clarkii (>15 g) were not significantly correlated with the claw weight and the claw body ratio (P > 0. 05), but were extremely positively correlated with the abdomen meat weight and the δ13C value (P<0.01) . It showed that the utilization of diet by these crayfish had become a key factor in determining their abdomen meat percentage. 4) There was a significant negative correlation between the claw weight and the δ13C value (P<0.05) in all collected normal crayfish. It could be inferred that individuals with well-developed claws tend to eat more P. crispus which with lower δ13C value. When the diet was sufficient, the lack of claws did not significantly affect the feeding and growth of P. clarkii (P<0.05) . It is concluded that there are significant correlation between feeding habits, morphology parameters, weight parameters, and abdomen meat percentage of P. clarkii, the diet is the main nutrient source for the abdominal muscle growth of P. clarkii in this study, but even when the diet is sufficient, P. clarkii still feeds heavily on aquatic plants. Traditional methods of stable nitrogen isotope trophic level study may not suitable for aquaculture ecosystems which are strongly influenced by diets. The results of this study can provide basic data for the genetic selection of P. clarkii and the ecological research on the integrated breeding model of rice-crayfish. © 2023 Chinese Journal of Animal Nutrition. All rights reserved.     

Evaluation Modeling of the Best College Coaches

We construct several models to select the best five coaches in different files at college for the previous century.Frist of all,aiming at the college coaches’major diathesis,a scientific questionnaire is built up.we select reasonably four aspects:ability,career,personal achievement,matches played,to compare coaches’achievement by predigesting the integrated evaluation index system based on the online data from NCAA[1].Finally,we get the rough relative weight of the four aspects.Then we study the accurate weight.First,we use AHP to get more accurate weight at the foundation of the rough relative weight.However,the weight is slightly subjective.Therefore,we filter the collected data,and employ Entropy Method to get weight.Finally,the Meta Synthesis Weight Approach is stipulated to combine the two methods and get the ultimate weight.In the end,we calculate the score every coach get and obtains the ranking..Then,we calculate the scores in weighted way based on the weight of Model.     

Effects of the dietary nonfiber carbohydrate content on lactation performance,rumen fermentation,and nitrogen utilization in mid-lactation dairy cows receiving corn stover

Background: Corn stover(CS) is an abundant source of feed for livestock in China. However, it is low in nutritional value that we have been seeking technologies to improve. Previous studies show that non-fiber carbohydrate(NFC)might limit the utilization of a CS diet by lactating dairy cows. Thus, this study was conducted to investigate the lactation performance and rumen fermentation characteristics in lactating cows consuming CS with two contents of NFC compared to an alfalfa hay-containing diet. Twelve Holstein cows were used in a replicated 3 × 3 Latin square design with three dietary treatments:(1) low-NFC diet(NFC = 35.6%, L-NFC),(2) high-NFC diet(NFC = 40.1%,H-NFC), and(3) alfalfa hay diet(NFC = 38.9%, AH).Results: Intake of DM was lower for cows fed H-NFC compared to L-NFC and AH, while the milk yield was higher in AH than in H-NFC and L-NFC(P 0.01). The feed efficiency(milk yield/DM intake, 1.15 vs. 1.08, P 0.01) were greater for cows fed H-NFC than L-NFC. The contents of milk protein and lactose were not different among the groups(P 0.11), but milk fat content was higher for cows fed H-NFC and L-NFC compared to AH(P 0.01). The rumen ammonia nitrogen concentration and the concentrations of urea nitrogen in blood and milk were lower for cows fed H-NFC and AH compared to L-NFC(P 0.05). The concentrations of rumen propionate and total volatile fatty acids were different among groups(P 0.05) with higher concentration for cows fed AH compared to H-NFC and L-NFC, and acetate concentration tended to be different among groups(P = 0.06).Conclusions: From the results obtained in this study, it was inferred that the increased NFC content in a diet containing corn stover can improve the feed efficiency and benefit the nitrogen conversion.     

Evaluation of adaptability of naked oat varieties in the alpine region of North China based on the AMMI model and GGE Biplot北大核心CSCD

In order to comprehensively evaluate the productivity, stability and adaptability of varieties of naked oats, as well as the discriminative power and representativeness of testing sites in the alpine region of North China, data for six naked oat varieties and six testing sites in 2019 were analyzed and evaluated using the AMMI （additive main effects and multiplicative interaction） model and GGE （genotype main effect plus genotype-environment interaction） biplot. It was found that analyses of naked oats regional trial results using the two methods together reduced the statistical error and increased the ability to declare variety means significantly different, compared to traditional ANOVA methods. It was found that genotype, environment, and genotype×environment interaction effects all contributed to differences in grain yield. Variety 200910-28-4-3（G2） showed the best performance in both grain yield and stability of yield across sites, followed by varieties 200910-5-2（G3） and 200910-22-1（G4）. In terms of the selection of regional adaptability test sites for varieties, Ulanqab pilot in Inner Mongolia had both good representativeness and strong discriminability, and was the most ideal test site. Chongli Shizigou Seed Farm and Zhangbei Base were also comparatively good test sites. This study provided a scientific evaluation of methodology for performance testing of naked oat varieties in the alpine region of north China and the results basis will assist future breeding and promotion. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

Estimates of genomic inbreeding and identification of candidate regions that differ between Chinese indigenous sheep breeds

Background:A run of homozygosity(ROH)is a consecutive tract of homozygous genotypes in an individual that indicates it has inherited the same ancestral haplotype from both parents.Genomic inbreeding can be quantified based on ROH.Genomic regions enriched with ROH may be indicative of selection sweeps and are known as ROH islands.We carried out ROH analyses in five Chinese indigenous sheep breeds;Altay sheep(n=50 individuals),Large-tailed Han sheep(n=50),Hulun Buir sheep(n=150),Short-tailed grassland sheep(n=150),and Tibetan sheep(n=50),using genotypes from an Ovine Infinium HD SNP BeadChip.Results:A total of 18,288 ROH were identified.The average number of ROH per individual across the five sheep breeds ranged from 39(Hulun Buir sheep)to 78(Large-tailed Han sheep)and the average length of ROH ranged from 0.929 Mb(Hulun Buir sheep)to 2.544 Mb(Large-tailed Han sheep).The effective population size(Ne)of Altay sheep,Large-tailed Han sheep,Hulun Buir sheep,Short-tailed grassland sheep and Tibetan sheep were estimated to be 81,78,253,238 and 70 five generations ago.The highest ROH-based inbreeding estimate(FROH)was 0.0808 in Large-tailed Han sheep,whereas the lowest F_ROHwas 0.0148 in Hulun Buir sheep.Furthermore,the highest proportion of long ROH fragments(>5 Mb)was observed in the Large-tailed Han sheep breed which indicated recent inbreeding.In total,49 ROH islands(the top 0.1% of the SNPs most commonly observed in ROH)were identified in the five sheep breeds.Three ROH islands were common to all the five sheep breeds,and were located on OAR2:12.2-12.3 Mb,OAR12:78.4-79.1 Mb and OAR13:53.0-53.6 Mb.Three breed-specific ROH islands were observed in Altay sheep(OAR15:3.4-3.8 Mb),Large-tailed Han sheep(ORA17:53.5-53.8 Mb)and Tibetan sheep(ORA5:19.8-20.2 Mb).Collectively,the ROH islands harbored 78 unique genes,including 19 genes that have been documented as having associations with tail types,adaptation,growth,body size,reproduction or immune response.Conclusion:Different ROH patterns were observed in five Chinese indigenous sheep breeds,which reflected their different population histories.Large-tailed Han sheep had the highest genomic inbreeding coefficients and the highest proportion of long ROH fragments indicating recent inbreeding.Candidate genes in ROH islands could be used to illustrate the genetic characteristics of these five sheep breeds.Our findings contribute to the understanding of genetic diversity and population demography,and help design and implement breeding and conservation strategies for Chinese sheep.     

Influence of starch sources and dietary protein levels on intestinal functionality and intestinal mucosal amino acids catabolism in broiler chickens

Background: There is growing interest in carbohydrate and protein nutrition to enhance the efficiency of animal production. Reduced-crude protein diets depress environmental pollution and feeding cost, but the challenge to their adoption is maintaining digestive function and growth performance of birds. The present study was conducted to evaluate the influence of different dietary starch sources and protein levels on intestinal functionality and mucosal amino acid catabolism.Methods: Six dietary treatments, based on maize and soybean meal, were offered to 360 AA+male chicks from 6 to 35 d post-hatch as a 3 × 2 factorial array. Either waxy rice or amylose was added to a conventional maize-soy diet to provide three sources of starch with different digestion rates and relatively high and low dietary protein levels. Growth performance, parameters of intestinal functionality and concentrations of free amino acid in the portal circulation were determined.Results: In the grower phase, starch source influenced(P 0.02) weight gain as diets containing amylose supported significantly higher weight gains than waxy rice. Significant increase of ileal ATP concentrations and Na+/K+-ATPase activity were found in amylose treatment. Also, amylose decreased BrdU positive cell numbers and down-regulated m RNA expression for CASP-3. GOT activity in the ileum was higher(P 0.01) in birds offered low protein diets and there was a trend(P = 0.057) for waxy rice as a starch source to increase ileal GOT activities. There was a significant influence on the concentration of seventeen amino acids in the portal circulation with tryptophan the one exception. Waxy rice as a starch source generated 13.6% and 22.4% numerically higher concentrations of non-essential amino acids than maize and amylose, respectively.Conclusions: Amino acid catabolism in the gut mucosa is subject to nutritional regulation. Given that amino acids can be spared from catabolism in the gut mucosa by supplementation of amylose, it follows their post-enteral availability would be improved and intestinal energy would be derived more efficiently from glucose.     

Supplementation with sodium butyrate improves growth and antioxidant function in dairy calves before weaning

Background: There is increasing research interest in using short-chain fatty acids(SCFAs) including butyrate as potential alternatives to antibiotic growth promoters in animal production. This study was conducted to evaluate the effects of supplementation of sodium butyrate(SB) in liquid feeds(milk, milk replacer, and the mixture of both)on the growth performance, rumen fermentation, and serum antioxidant capacity and immunoglobins in dairy calves before weaning. Forty healthy female Holstein calves(4-day-old, 40 ± 5 kg of body weight) were housed in individual hutches and randomly allocated to 1 of 4 treatment groups(n = 10 per group) using the RAND function in Excel. The control group was fed no SB(SB0), while the other three groups were supplemented with 15(SB15),30(SB30), or 45(SB45) g/d of SB mixed into liquid feeds offered. The calves were initially fed milk only(days 2 to 20), then a mixture of milk and milk replacer(days 21 to 23), and finally milk replacer only(days 24 to 60).Results: The SB supplementation enhanced growth and improved feed conversion into body weight gain compared with the SB0 group, and the average daily gain increased quadratically with increasing SB supplementation. No significant effect on rumen pH;concentrations of NH_3-N, individual and total VFAs;or acetate:propionate(A:P) ratio was found during the whole experimental period. Serum glutathione peroxidase activity increased linearly with the increased SB supplementation, while the serum concentration of maleic dialdehyde linearly decreased. Serum concentrations of immunoglobulin A, immunoglobulin G, or immunoglobulin M were not affected by the SB supplementation during the whole experimental period.Conclusions: Under the conditions of this study, SB supplementation improved growth performance and antioxidant function in pre-weaned dairy calves. We recommended 45 g/d as the optimal level of SB supplementation mixed into liquid feeds(milk or milk replacer) to improve the growth and antioxidant function of dairy calves before weaning.     

Characteristics of Slope Runoff and Sediment of Different Vegetation Types under Individual Rainfall Events in Loess Hilly and Gully Region北大核心CSCD

The runoff plots of Anjiagou watershed were selected as the research object in Dingxi City,Gansu Province,and the characteristics of rainfall infiltration, runoff and sediment of different vegetation types were studied using the observed data of runoff and sediment under natural rainfall conditions. The results showed that: the infiltration rate of soil under different vegetation types increased linearly with the increase of rain intensity, while the relation between the infiltration rate and the rainfall duration was a power function. The runoff coefficient of pine forest (15.97%~19.88%) was the largest, the wheat field (10.91%~17.32%) and sea buckthorn forest (9.51%~17.47%) the second,the wheatgrass meadow (4.62%~8.30%) and the alfalfa land (6.82%~10.66%)were the smallest. In the meanwhile,the relation between runoff coefficient (1%~28%) and rainfall presented a power function (P<0.05). The order of average sediment concentration was as follow: wheat field (16.49~22.71 g·L-1) > alfalfa land (12.66~16.91 g·L-1) > sea buckthorn forest (7.04~11.8 g·L-1) > pine forest (6.95~7.78 g·L-1) > wheatgrass meadow(5.53~7.71 g·L-1). There was a positive correlation between sediment concentration and soil erosion rate and rainfall erosivity (P<0.01),which can be quantified separately by linear function and quadratic function. The results can provide references for optimizing configuration of water and soil conservation in Loess hilly and gully region. © 2019 China Agricultural University. All rights reserved.     

Effects of novel vaccines on weight loss in diet-induced-obese （DIO） mice

The purpose of the study was to test the therapeutic effects of novel vaccines for reducing weight gain and increasing weight loss in diet induced obesity (DIO) model. Male C57BL/6 J mice, fed a 60% Kcal fat diet for 8 weeks prior to the start of the study, were vaccinated via the intraperitoneal route with two formulations (JH17 & JH18) of chimeric-somatostatin vaccines at 1 and 22 days of the study. Control mice were injected with PBS. All mice continued to be feed the 60% Kcal fat diet for the 6 week study. Body weights were measured two times a week and food intake was measured weekly. At week 6, mice were euthanized and a terminal bleed was made and antibody levels to somatostatin and levels of insulin-like growth factor 1 (IGF-1) were determined. Vaccination with both vaccine formulations induced a statistically significant body weight change over the study period, as compared with PBS controls. Percentage of baseline body weight was also significantly affected by vaccination during the study period. Vaccinates finished the study at 104% and 107% of baseline weight, JH17 & JH18 respectively, while untreated controls reached 115% of baseline weight. Food intake per mouse was similar in all mouse groups during the entire study. Control mice did not demonstrate any antibody titers to somatostatin, while all vaccinated mice had measurable antibody responses (> 1:500,000 titer). IGF-1 levels were not statistically significant among the groups, but were elevated in the JH18 vaccinates (mean 440.4 ng/mL) when compared with PBS controls (mean 365.6 ng/mL). Vaccination with either JH17 or JH18 chimeric-somatostatin vaccines produced a statistically significant weight loss as compared with PBS controls (P < 0.0001), even though the DIO mice with continually fed a 60% Kcal fat diet. The weight loss/lower weight gain observations were even more significant, as all mice consumed similar amounts of food for the entire study. The presence of high levels of anti-somatostatin antibodies at 6 weeks was correlative with the weight observations and confirmed the success of vaccination.     

Evaluation of alfalfa inter-seeding effect on bahiagrass baleage fermentation and lactating Holstein performance

Background：Previous research indicates that bahiagrass may be successfully conserved as baleage,but nutritive value is typically low for lactating dairy cows.The purpose of this study was to determine the effect of adding modest amounts of alfalfa forage（22%）,achieved by inter-seeding alfalfa into an existing bahiagrass pasture,on baleage nutritive value and lactation performance of Holstein cows.Forage treatments employed were monoculture bahiagrass baleage（MBB;negative control）,bahiagrass-alfalfa mixture baleage（BAB） and conventional corn silage（CCS;positive control）.Thirty six mid lactation Holstein cows[34.8 ±5.8 kg 3.5%fat-corrected milk and 112 ± 19 d in milk（DIM）]were stratified according to milk yield and DIM and assigned randomly to 1 of 3 forage treatments.Cows were trained to Calan feeding gates and were offered a common CCS-based TMR in a 10-d covariance period followed by a 42-d treatment feeding period.Results：The BAB contained more protein and less NDF than MBB（12.6 vs 10.3%CP and 71.8 vs 76.6%NDF）.Diet DMI was similar for MBB and BAB（19.5 vs 21.6 kg/hd/d）,but cows consumed more of the CCS diet（25.5 kg/hd/d）than either baleage-based diet.Cows offered BAB tended to produce more milk than cows offered MBB based TMR（28.4 vs 26.1 kg/hd/d）,but both baleage diets generated less milk than CCS-based diets（33.1 kg/hd/d）.Milk cumpusition was similar across diets except for milk protein concentrations which were higher tor CCS than either MBB or BAB diets;however,milk urea nitrogen（MUN） was lowest for cows fed CCS diets.Cow BW gain was higher for BAB than MBB implying that a portion of the higher energy contributed by the alfalfa was being used to replenish weight on these mid lactation cows.Conclusions：Data from this study indicate that alfalfa inter-seeded in bahiagrass sod that produces BAB with as little as 22%alfalfa may improve nutritive value compared to monoculture bahiagrass baleage and marginally improve lactation performance of Holstein cows.Howev