Effects of Lactic Acid Bacteria and Fructooligosaccharides on Growth Performance,Nutrient Digestibility and Serum Biochemical Indices of Arctic Foxes (Alopex lagopus) during Early Growth Period北大核心CSCD

This experiment was conducted to study the effects of dietary lactic acid bacteria (LAB) and fructooligosaccharides (FOS) on growth performance, nutrient digestibility and serum biochemical indices of Arctic foxes (Alopex lagopus) during early growth period. Sixty male post-litter Arctic foxes with the average body weight of (1.16±0.15) kg and at the age of (45±3) days were randomly assigned to 4 groups with 3 replicates per group and 5 foxes per replicate. The foxes were fed the following diets, respectively: basal diet (control group), basal diet+3×109 CFU / kg LAB (LAB group), basal diet+5 g / kg FOS (FOS group) and basal diet+3×109 CFU / kg LAB+5 g / kg FOS (LAB+FOS group). The experiment lasted for 30 days. The results showed as follows: 1) on the days 1 to 15, the diarrhea rate of foxes in the LAB group and LAB+FOS group was significantly lower than that in the control group and FOS group (P<0.05). On the days 16 to 30, the average daily gain of foxes in the LAB+FOS group was significantly higher than that in the control group and FOS group (P<0.05), but had no significant difference with LAB group (P>0.05); the diarrhea rate of foxes in the LAB+FOS group was significantly lower than that in the control group and FOS group (P<0.05), but had no significant difference with LAB group (P>0.05); compared with the FOS group, the feed to gain ratio of foxes in the LAB+FOS group was significantly decreased (P<0.05). 2) The dry matter digestibility of foxes in the LAB + FOS group was significantly higher than that in the control group and FOS group (P < 0.05), but had no significant difference with LAB group (P>0.05). There were no significant differences in nitrogen intake, fecal nitrogen, urine nitrogen, nitrogen deposition, net protein utilization and protein biological value among all groups (P>0.05). 3) Serum total protein (TP) content of foxes in the LAB+FOS group was significantly higher than that in the FOS group (P<0.05), but had no significant difference with control group and LAB group (P>0.05). Serum albumin (ALB) content of foxes in the LAB group was significantly higher than that in the control group and FOS group (P<0.05), but had no significant difference with LAB+ FOS group (P>0.05). Serum urea nitrogen (UN) content of foxes in the LAB+FOS group was significantly decreased compared with the control group (P < 0. 05). In conclusion, the combined supplementation of 3 × 109 CFU / kg LAB and 5 g / kg FOS in the diet is beneficial to reduce diarrhea rate, improve dry matter digestibility, improve body immune level, and promote the growth of Arctic foxes during early growth period. © 2023 Chinese Journal of Urology. All rights reserved.     

Effects of Dietary Supplemented with Combined Yeast⁃Bacillus coagulans Fermentation Culture on Intestinal Morphology,Intestinal Permeability,Cecal Fermentation and Microflora of Rex Rabbits北大核心CSCD

This experiment was conducted to investigate the effects of dietary supplemented with combined yeast and Bacillus coagulans fermentation culture on intestinal morphology, intestinal permeability, cecal fer⁃ mentation and microflora of Rex rabbits. A total of 160 healthy Rex rabbits weaned at 35⁃day⁃old with similar body weight were randomly allocated to 4 groups with 8 replicates per group and 5 rabbits per replicate. Rex rabbits in the control group were fed a basal diet, while the others in experimental groups were fed experimental diets supplemented with 0.01%, 0.02% and 0.04% combined yeast and Bacillus coagulans fermentation cul⁃ ture based on the basal diet, respectively. The pretrial period lasted for 7 days and formal period lasted for 56 days. The results showed as follows: 1) the crypt depth of jejunum in the 0.02% and 0.04% added groups was significantly lower than that in the control group (P<0.05), the jejunum villus height / crypt depth ratio in the 0.02% added group was significantly higher than that in the control group (P < 0. 05), and the ileum villus height in the 0.04% added group was significantly higher than that in the control group (P<0.05) . 2) The ac⁃ tivity of diamine oxidase (DAO) in serum of 0.01% and 0.02% added groups was significantly lower than that in the control group (P<0.05), but there was no significant difference in the content of D⁃lactic acid (D⁃LA) in serum among all groups (P>0.05). 3) There were no significant differences in the pH of jejunum, ileum and cecum among all groups (P>0.05). There were no significant differences in the concentrations of acetic acid, propionic acid, butyric acid and total volatile fatty acid and the ratios of acetic acid, propionic acid and butyric acid in cecum among all groups (P>0.05). 4) Compared with the control group, the Simpson index of 0.02% and 0.04% added groups showed an increasing trend (0.05≤P<0.10). At the phylum level, the rela⁃ tive abundance of Verrucomicrobia showed a trend of decreasing first and then increasing with the combined yeast and Bacillus coagulans fermentation culture increasing (0.05≤P<0.10); the relative abundance of Te⁃ nericutes in the 0.02% added group was significantly higher than that in the 0.01% and 0.04% added groups (P<0.05), but there was no significant difference between the added groups and the control group (P>0.05). At the genus level, the relative abundance of Ruminococcaceae_UCG⁃014, Akkermansia, dgA⁃11_gut_group, Paramuribaculum and Subdoligranulum showed a trend of change with the combined yeast and Bacillus coagu⁃ lans fermentation culture increasing (0.05≤P<0.10). In summary, dietary supplemented with combined yeast and Bacillus coagulans fermentation culture can improve the intestinal morphology and reduce intestinal perme⁃ ability, but has no significant effects on the pH of jejunum, ileum and cecum and cecum fermentation, and can improve the microbial diversity of cecum of Rex rabbits. The recommended addition level is 0.02% to 0.04% based on the previous results of growth performance. © 2023 Chinese Journal of Clinical Research. All rights reserved.     

Effect of Poly-β-hydroxybutyrate on Reproductive Performance and Larval Development of Fenneropenaeus chinensis

In the present study, Fenneropenaeus chinensis individuals were assigned into six groups, and fed with a diet supplemented with 0(Con-trol), 0.5%(Group E0.5), 1.0%(Group E1.0), 2.0%(Group E2.0), 3.0%(Group E3.0) or 5.0%(Group E5.0) of poly-β-hydroxybutyrate(PHB) during their growth and spawning periods, to explore the effect of PHB on the reproductive performance of parents and the development of larvae. The experi-ment was lasted for 192 d to measure the mortality rate, relative percentage of survival(RPS), weight gain rate(WGR), specific growth rate(SGR) and cycle of gonadal development of parental shrimps, number of eggs, number of nauplii, stages of larval development and metamorphosis. The results indicated that PHB had an obvious effect on the fecundity of parental shrimps and growth performance of larva. Compared with control group, the mortality rate of broodstock in experimental groups decreased initially and increased subsequently with the increase of PHB concentration, while RPS showed an opposite pattern. The mortality rate of group E2.0 was the lowest among all groups, showing significant difference from that of other groups(P﹤0.05) except group E1.0(P﹥0.05). WGR of all experimental groups was higher than that of the control group, among which, group E2.0 and group E5.0 had significantly higher WGR than the control(P0.05). However, there was no significant difference in the cycle of gonadal development between the experimental groups and the control group(P ﹥ 0.05). The numbers of eggs and nauplii in the experimental groups were higher than those of the control group. And the numbers of eggs and nauplii in group E2.0 were significantly higher than those of the control(P ﹤ 0.05), bud showed no significant difference from those of other groups(P﹥0.05). However, there was no significant difference in the duration of larval devel-opment and metamorphosis among all the groups. In summary, PHB is capable of improving the reproductive performance of parents and the survival and development of larva in F. chinensis, and 2.0% is the optimal concentration of PHB supplemented to the diet.     

Effects of Faba Bean Supplementation on Growth Performance,Intestinal Digestive Enzyme Activities,Intestinal Morphology and Intestinal Flora of Tilapia (Oreochromis niloticus)北大核心CSCD

This study was conducted to investigate the effects of faba bean supplementation on the growth performance, intestinal digestive enzyme activities, intestinal morphology and intestinal flora of tilapia (Oreochromis niloticus). A total of 600 genetic improvement of farmed tilapia with an initial body weight of (500.23± 0.34) g were randomly divided into 4 groups with 3 replicates per group and 50 fish per replicate. Four isonitrogenous and isolipidic experimental diets containing 0 (C0 group, as control), 15% (C15 group), 30% (C30 group) and 60% (C60 group) faba bean were fed to fish during the 100-d feeding trial. Results showed as follows: 1) there were no significant differences in the weight gain rate, specific growth rate, feed coefficient ratio and hepatosomatic index among the groups (P>0.05), the protein efficiency ratio and survival rate in C60 group were significantly higher than those in C0 and C15 groups (P<0.05). 2) There were no significant differences in the activities of amylase, lipase and trypsin among the groups (P>0.05). 3) Compared with the C0 group, the C15, C30 and C60 groups had significantly lower intestinal villus height, villus thickness and muscle thickness (P<0.05). 4) The Simpson index of intestinal flora of tilapia in C15, C30 and C60 groups was lower than that in C0 group, and the difference was significant between C30 and C0 groups (P< 0.05). 5) The intestinal core flora of the four groups of tilapia were mainly Cyanobacteria, Actinobacteriota, Firmicutes, Proteobacteria and Fusobacteriota. Compared with the C0 group, the relative abundance of Proteobacteria in C15, C30 and C60 groups had a significant reduction (P<0.05), and the relative abundances of Fusobacteriota and Cetobacterium in C15 and C60 groups had a significant reduction (P<0.05). To conclude, under the conditions of isonitrogenous and isolipidic, diets supplemented with 15% to 60% faba bean have no significant effects on the growth performance and intestinal digestive enzyme activities of tilapia, but can significantly reduce the intestinal villi height, villus width and muscle thickness, decrease the relative abundance of Proteobacteria and the diversity of intestinal flora. © 2023 Authors. All rights reserved.     

Effects of Dietary Tributyrin on Growth Performance,Serum Biochemical Indices,Immune Function and Antioxidant Capacity of Juvenile Yellow Catfish (Pelteobagrus fulvidraco)北大核心CSCD

This experiment was conducted to investigate the effects of dietary tributyrin on growth performance, serum biochemical indices, immunity function and antioxidant capacity of juvenile yellow catfish (Pelteobagrus fulvidraco). A total of 480 juvenile yellow catfish with an initial body weight of (5.53±0.02) g were selected and randomly divided into 4 groups with 3 replicates in each group, and 40 fish in each replicate. Four isonitrogenous and isolipid experimental diets were fed with 0 (G0), 500 (G1), 1 000 (G2) and 2 000 mg/kg (G3) triglyceride, respectively. The experiment lasted for 56 days. The results showed as follows: 1) weight gain rate and feed efficiency rate in G2 group were significantly higher than those in other groups (P<0.05). The fatness in G1 group was significantly lower than that in G0 and G3 groups (P<0.05), but there was no significant difference between G1 group and G2 group (P>0.05). 2) The serum glucose content in G3 group was significantly higher than that in G1 and G2 groups (P<0.05), and there were no significant differences in the serum contents of total protein, albumin, globulin, triglyceride, urea nitrogen and the activities of alanine aminotransferase and aspartate aminotransferase among all groups (P>0.05). 3) Compared with G0 group, serum lysozyme activity in G1, G2 and G3 groups was significantly increased (P<0.05), serum alkaline phosphatase activity in G1 and G2 groups was significantly increased (P<0.05), and serum immunoglobulin M content in G2 group was significantly higher than that in G3 group (P<0.05). There was no significant difference in serum complement C3 content among all groups (P>0.05). 4) Compared with G0 group, serum total antioxidant capacity in G1 group was significantly increased (P<0.05), and serum super-oxide dismutase activity in G1, G2 and G3 groups was significantly increased (P<0.05). The serum catalase activity in G3 group was significantly higher than that in G0, G1 and G2 groups (P<0.05), but there were no significant differences in serum glutathione peroxidase activity, glutathione and malondialdehyde contents among all groups (P>0.05). In conclusion, dietary supplementation of 500 to 2 000 mg/kg triglyceride can significantly improve non-specific immune and antioxidant capacity of yellow catfish, and dietary supplementation of 1 000 mg/kg triglyceride can significantly improve weight gain rate and feed efficiency of yellow catfish. Combined with the comprehensive evaluation of growth performance, serum immunity and antioxidant indexes, the optimal supplemental level of triglyceride in yellow catfish diet is 1 000 mg/kg. © 2023 Authors. All rights reserved.     

Effects of Soybean Meal Replaced by Fermented Plant Protein Compound on Growth,Immune, Antioxidant and Intestinal Microflora Structure of Black Carp (Mylopharyngodon piceus)北大核心CSCD

This experiment was conducted to study the effects of soybean meal replaced by fermented plant protein compound on growth, immune, antioxidant and intestinal microflora structure of black carp (Mylopharyn-godon piceus). The different proportions (1∶1 and 2∶1) of fermented cottonseed meal and fermented rapeseed meal were used to replace 0 (control group), 50% and 75% soybean meal in the basic diet, respectively, 5 kinds of isonitrogenous and isoenergetic experimental diets were prepared, and the black carp with initial weight of (6. 04 ± 0. 18) g were fed for 8 weeks. The results showed that there were no significant differences on growth performance, morphological indicators and body composition among all group (P>0.05). There were no significant differences on serum complement 3, malondialdehyde, albumin contents and lysozyme activity among all group (P>0.05). The serum complement 4 content in 50% replacement group was significantly higher than that in other groups (P<0.05), and the serum immunoglobulin M content in 75% replacement group was significantly higher than that in the control group (P<0.05). There were no significant differences on hepatopancreas superoxide dismutase, catalase, alkaline phosphatase activities and total antioxidant capacity and total cholesterol content among all group (P>0.05). There were no significant differences on intestinal α-amylase and lipase activities among all group (P>0.05), and the intestinal pepsin activity in fermented cottonseed meal and fermented rapeseed meal replacing 75% soybean meal with 1 ∶ 1 proportion group was significantly higher than that in the control group (P<0.05). The dominant microflora in intestine of black carp at the phylum level were Proteobacteria, Firmicutes, Fusobacteria and Planctomycotes, and the dominant bacteria at the genus level were Aeromonas, Cetobacterium, Ralstonia and Plesiomonas. There were no significant differences on the relative abundances of intestinal main microflora among all group (P>0.05). To sum up, under the experimental conditions, the high proportion (75%) of fermented plant protein replacing soybean meal do not cause hepatopancreas damage and intestinal microflora structure change of black carp, and even improve the activities of some immune indicators in serum and intestinal protease activity, and the compound proportion of fermented cottonseed meal and fermented rapeseed meal have no significant effects on growth performance, morphological indicators, body composition, hepatopancreas antioxidant indexes and intestinal microflora structure of black carp. © 2023 Chinese Journal of Urology. All rights reserved.     

Effects of Dietary Ampitheoe sp. Powder on Growth and Lipid Contents of Litopenaeus vannamei北大核心CSCD

This experiment was conducted to investigate the effects of dietary Ampitheoe sp. powder on the growth and the contents of astaxanthin, triglyceride (TG), total cholesterol (TCHO) and fatty acids of Litopenaeus vannamei. A total of approximately 6 777 L. vannamei with an initial body weight of (1. 80 ± 0.72) g were randomly divided into 3 groups, and there were 3 replicates (753 shrimp per replicate) in each group. Those shrimp fed diets containing 0 (D0 group), 8. 25% (D8. 25 group) and 33% (D33. 00 group) Ampitheoe sp. powder, respectively. The feeding trial lasted for 40 days. The results showed as follows: 1) the final body weight, weight gain rate, specific growth rate, yield and survival rate in D33.00 group were significantly higher than those in D0 group (P <0.05), whereas the feed conversion ratio was significantly lower than that in D0 group (P <0.05) . However, there was no significant difference between D33.00 group and the D8. 25 group in those indexes (P >0.05) . 2) The astaxanthin content in carapace, hepatopancreas and muscle of L. vannamei in D8.25 and D33. 00 groups was significantly higher than that in D0 group (P < 0. 05); that in D33.00 group was significantly higher than that in D8. 25 group (P < 0. 05) . 3) TG content in haemolymph, hepatopancreas and muscle in D8. 25 and D33. 00 groups was significantly lower than that in D0 group (P < 0.05); the TCHO content in hepatopancreas in D8. 25 group was significantly higher than that in D0 and D33.00 groups (P <0.05); TCHO content in muscle in D33.00 group was significantly higher than that in D0 group (P <0.05) . 4) The contents of eicosapentaenoic acid (EPA) and arachidonic acid (AA) in hepatopancreas in D33.00 group were significantly higher than those in D0 group (P <0.05) . The EPA content in muscle in D33.00 group was significantly higher than that in D0 group (P < 0. 05) . In conclusion, adding Ampitheoe sp. powder into the diet can improve the growth performance, the contents of astaxanthin, EPA and AA in L. vannamei, and affect the accumulation of TG and TCHO, which can be used as a functional diet in aquaculture. Considering the cost, the supplementation level of 8. 25% Ampitheoe sp. powder is more appropriate. © 2023 Chinese Journal of Pediatric Surgery. All rights reserved.     

Sexual maturation in hens is not associated with increases in serum leptin and the expression of leptin receptor mRNA in hjpothalamus

Background： In mammals, leptin is an attractive candidate for mediating the metabolic signal and the reproductive function via the specific receptor in hypothalamus. However, till now, the role of leptin on reproduction in birds is less well established. This experiment was conducted to elucidate the role of leptin on the onset of reproduction in bird, as a first step, to detect the changes of peripheral leptin and leptin receptor mRNA expression in hypothalamus between mature and immature hens at the same age. 120 ISA brown pullets at D60 were allocated randomly into two groups, long light （LL） group being raised under artificial light regimes with incrementally increased light phase （from 8 L：]6D to 14 L：]2D） and short light （SL） group raised on consistent light （8 L：16D） for 12 wk. Results： The results showed that pullets in LL group reached sexual maturation 15 d earlier than those in SL group. Serum E2 showed a significant increase with age, but no difference was observed between two groups. Serum leptin concentration decreased significantly from D112 to D136 in LL, and was markedly higher in LL group than that in SL at D112, while there was no significant difference between two groups at D136. Leptin receptor and GnRH-I mRNA expression in hypothalamus were significantly increased with age, yet there was no significant difference between SL and LL chickens at the same age. The expression of FSH-13 and LH-13 mRNA in pituitary was increased with age but did not show significant difference between LL and gland, and decreased from D112 to D136 in LL but not groups at the same age. SL group. GnfiH-I mRNA expression was very rich in pinea n SL group, and there was no difference between two Conclusions： These results indicate that the earlier sexual maturation in hens induced by long-light regime is not accompanied with an increase in serum leptin or leptin receptor gene expression in hypothalamus, or genes expression in HPG axis.     

Biodiversity Characteristics and Biomass of Artificial Transplanting Leymus chinensis grassland in Soda Saline-Alkali land of Songnen Plain北大核心CSCD

In order to explore the effect of Leymus chinensis transplanting on the biodiversity and productivity of saline alkali grassland in Songnen Plain,a comparative experiment was conducted in the transplanting Leymus chinensis grassland. The results showed that the transplanting of Leymus chinensis enhanced plant species and the density of the grassland community. The total plant density under the transplanting of Leymus chinensis was 566.20 plant·m-2,6.85 times as much as that in the control (82.60 plant·m-2),and the difference between the treatments was significant (P<0.05),and the transplanting of Leymus chinensis increased the diversity index of Shannon-Wiener,the evenness index of Pielou and the richness of Margalf species. The total biomass of the community was higher than that in the control. In addition,the total biomass of the transplanting of Leymus chinensis was 357.77 g· m-2,2.14 times as much as that in the control (167.34 g·m-2),and the difference between the treatments was significant (P<0.05),which indicated that the transplanting Leymus chinensis increased the productivity of the plant community,and greatly increased the grassland output benefit, The total income was 3938.00 yuan·hm-2 for the transplanting of Leymus chinensis,7.37 times higher than that in the control (534.40 yuan·hm-2),and the difference between treatments was very significant (P<0.01).Transplanting technology of Leymus chinensis not only improved the biodiversity of the system,but also doubly increased the biomass and economic benefits,So it was a technical model which was worth of popularizing and applying in the saline alkali area of the Western Songnen Plain. © 2019 China Agricultural University. All rights reserved.     

Changes of hepatic biochemical parameters and proteomics in broilers with cold-induced ascites

Ascites syndrome is still a problem for chicken industry in various parts of the world. Despite the intensive investigations of this syndrome for many years, its pathogenesis remains unclear. The objective of this study was to analyze the difference in hepatic proteomics between ascites and healthy broilers by two-dimensional electrophoresis （2-DE） and matrix-assisted laser desorption/ionization-time of flight mass spectrometry （MALDI-TOF-MS）. Changes of biochemical parameters of liver and blood were also determined. The results indicated that red blood cell counts （RBC）, hematocrit （HCT） and haemoglobin （HGB） of ascites broilers were significantly greater than healthy broilers. Hepatic malondialdehyde （MDA） level of ascites broilers was significantly increased, and the activity of total superoxide dismutase （T-SOD） was significantly decreased. Hepatic lactic acid （LD） level of ascitic broilers were significantly lower than healthy ones, Serum glucose and cholesterol level of ascites broilers were significantly increased, and serum globulin level was significantly decreased in ascites broilers. There was no significant difference in triglyceride （TG） and blood urea nitrogen （BUN） level. The activity of liver hexokinase （HK） and succinodehydrogenase （SDH） in ascites broilers was significantly decreased, and there was no significant difference in the activity of liver pyruvate kinase （PK） and Na＋-K＋-ATPase. The hepatic proteomics analysis showed that 18 proteins expression difference were identified between ascites and healthy broilers. These proteins were mainly involved in： 1） cytoskeleton; 2） glucose, lipids and amino acid metabolism; 3） cell secretion; 4） cell apoptosis; 5） signal transduction; 6） immune and inflammatory response; and 7） cellular redox homeostasis. Mitochondrial isoform phosphoenolpyruvate carboxykinase （M-PEPCK） mainly participates in gluconeogenesis of chicken liver. In conclusion, liver oxidative damage was significantly aggravated, but antioxidant capacity was decreased in cold-induced ascites broilers. Serum glucose level was significantly increased, with liver M-PEPCK expression higher in ascites broilers, which implied that some potential regulatory reagents may reduce ascites susceptibility and mortality under cold temperature by increasing liver gluconeogenesis level.     

Effects of Dietary Sodium Acetate on Lactation Performance and Rumen Microbiota of Dairy Goats北大核心CSCD

This experiment was conducted to investigate the effects of dietary sodium acetate on lactation performance and rumen microbiota of dairy goats. Fifteen healthy Xinong Saanen dairy goat ewes with similar body weight of (53.54±3.07) kg, the same parity (2 parities) and in mid-lactation [(60±5) d] were randomly divided into 3 groups with 5 replicates in each group. Dairy goats in the control group were fed a basal diet, and those in the experimental groups were fed the basal diet supplemented with 30 (experimental group I) and 60 g/ (d.head) (experimental group II) sodium acetate, respectively. The pre-trial period lasted for 7 days and the experimental period lasted for 21 days. The milk yield of dairy goats was recorded during the experiment. At the end of the experiment, milk samples were collected to analyze the changes in milk composition, and rumen contents of dairy goats were collected from two groups (control group and experimental group II) with significant differences in milk fat percentage. Gas chromatography and 16S rDNA sequencing technology were used to analyze the rumen fermentation parameters and rumen microbial composition and structure of dairy goats. The results showed as follows: 1) compared with the control group, dietary sodium acetate extremely significantly increased the daily milk yield of dairy goats (P<0.01), and the daily milk yield in experimental groups I and II was increased by 0.29 and 0.22 kg, respectively (P<0.01); in experimental group II, the milk fat percentage was significantly increased by 1.30 percentage points (P<0.01), and the non-fat solid content in milk was increased by 3.10% (P>0.05). 2) Compared with the control group, the rumen butyric acid content of dairy goats in experimental group II was significantly decreased (P<0.01), and there was no significant difference in rumen pH, the other volatile fatty acid content and acetic acid to propionic acid ratio (P>0.05). 3) Compared with the control group, the Sobs index, Chao1 index and Ace index of rumen microbiota in experimental group II were significantly increased (P<0.05); the results of similarity analysis (ANOSIM) also showed that there were significant differences in the structure of rumen microbiota between the two groups (P<0.05). 16S rDNA sequencing results showed that at the phylum level, Bacteroidetes and Firmicutes were the dominant phyla in the rumen of the two groups of dairy goats; at the genus level, Prevotella_1 was the dominant genus in the rumen. Compared with the control group, the relative abundances of Ruminococcus_1, Ruminococcaceae_UCG-005, Prevotellaceae_UCG-004 and Lachnoclostridium_12 in rumen of dairy goats in experimental group II were significantly increased (P<0.05), while the relative abundances of Succiniclasticum and Methanobrevibacter in rumen was significantly decreased (P<0.05). 4) The results of correlation analysis showed that rumen microbiota was correlated with daily milk yield, milk fat percentage, milk protein percentage and non-fat solid content of dairy goats. In conclusion, dietary 60 g/ (d.head) sodium acetate can significantly increase the daily milk yield and milk fat percentage, significantly reduce rumen butyrate content, and improve the lactation performance of dairy goats by improving rumen microbial composition and structure. © 2023 Authors. All rights reserved.     

The influences of SE infection on layers’ production performance,egg quality and blood biochemical indicators

Background： Salmonella enterica serovar Enteritidis （SE）, as a major cause of foodborn illness, infects humans mainly through the egg. However, the symptom of laying hens usually is not typical and hard to diagnosis. In the present study, it is studied that the influences of SE infection on layers＇ performance, egg quality and blood biochemical indicators. It will help us to improve the strategy to control SE infection in commercial layers. One hundred layers at 20 wk of age were divided into 2 groups, 60 hens for experiment and others for control. The experiment group was fed with the dosage of 108 CFU SE per hen. The specific PCR was used to detect the deposition of SE. On the 8 d after SE infection, 10 hens from the control group and 30 hens from the experimenta group were slaughtered to detect the SE colonization. The production performance, egg quality and blood biochemical indices were also analyzed. Results： The results showed that the colonization rate of SE was highest in caecum contents （55.17%） and lowest in vagina （17.24%）. For the eggs the detection rate of SE was highest on the eggshell （80.00%） and lowest in yolk （18.81%）. SE infection had no significant influence on production performance and egg qualities （P 〉 0.05）. The difference of laying rate between the experimental and control groups was less than 0.30%, and both were approximately equal to 82.00%. The blood analysis showed that the aspartic aminotransferase （AST） and alanine aminotransferase （ALT） of experimental group was significantly higher than those of control group （P 〈 0.05）. For experimental and control groups AST values were 236.22 U/I and 211.84 U/I respectively, and ALT values were 32.19 U/I and 24.55 U/I. All of coefficients were less than 20%. The colonization of SE in organs increases the enzyme activities of AST and ALT in blood. Conclusions： SE in feed could invade the oviduct and infect the forming eggs. It significantly increased the concentration of ALT and AST in blood. Ho     

Effects of plateau pika on the relationship between plant species diversity and functional diversity in alpine meadow北大核心CSCD

The relationship between plant species diversity and functional diversity in grassland will change with environmental changes. The plateau pika （Ochotona curzoniae） has an effect on the hydrothermal process of alpine meadow in its nesting area. However,it is not clear whether the disturbance of plateau pika effects the relationship between plant species diversity and functional diversity in alpine meadow. A random stratified and paired design was used to select plots in Luqu county in Gansu Province,and Qilian and Gonghe Counties in Qinghai Province and a field survey was conducted to investigate the effects of plateau pika disturbance on the relationship between plant species diversity and functional diversity of the alpine meadow. It was found that plateau pika disturbance significantly increased the plant species richness index and the species diversity index but did not significantly affect the species evenness index. Plateau pika disturbance significantly increased plant functional richness index （P< 0.05） but had no significant effect on the plant functional evenness index or the functional divergence index. With plateau pika disturbance effects,the relationship between plant functional richness index and species richness index changed from a logarithmic function to a quadratic function,and the relationship between plant functional evenness index and species evenness index changed from non-significant to significantly positive. In addition, positive correlations between functional richness index and species richness index,and functional richness index and species diversity index were significantly decreased,as were negative correlations between functional divergence index and species richness index,and functional divergence index and species diversity index were significantly decreased. The findings of this study provide basic information for understanding the mechanism of species coexistence of plant communities under plateau pika disturbance and help understanding of how plant diversity effects in an alpine meadow ecosystem function under plateau pika disturbance. © 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   

Characteristics of Evapotranspiration and Water Consumption of Typical Alpine Desert in the Tibetan Plateau During the Growing Season北大核心CSCD

To explore the law of water consumption in the underlying surface of a typical alpine desert on the Qinghai-Tibet Plateau, we analyzed the characteristics of ET change and water consumption on different time scales based on the raw eddy-covariance data and meteorological data measured in April to August 2019 from the observation tower on Tuotuohe weather station. The maximum hourly average ET appears at 2-3 p. m, reaching 0.46 mm·h-1; The maximum value of daily ET was 8.58 mm·d-1 on July 7, and the minimum value was 0.30 mm·d-1 on April 2; The ET increased first and then decreased during the growing season, the monthly ETmax was 120.68 mm in July and the ETmin was 64.80 mm in April; The total ET in 2019 growth season was 581.15 mm and the daily average was 4.01 mm. The total precipitation of the whole growing season was 235.70 mm, according to the difference between ET and precipitation(Pr) from April to August, water vapor exchange during the plant growth season was mainly characterized by water consumption on the land surface in 2019. © 2019 Authors. All rights reserved.     

Changes of Rumen Microbiota Density and Physicochemical Properties at Different pH北大核心CSCD

The aim of this experiment was to investigate the changes of rumen microbiota density and physicochemical properties at different pH. Five Holstein cows in dry milk period were selected as rumen fluid donors. Using in vitro method, five treatments were set according to the criteria of rumen acidosis, and the pH of culture medium was 6.5, 5.8, 5.5, 5.2 and 5.0, respectively, with five replicates in each treatment. After three hours of incubation, the changes of rumen microbiota density and physicochemical properties were measured. The results showed as follows: 1) with the decrease of pH, the rumen microbiota density showed a fluctuation change of first decreasing, then increasing and then decreasing, and the microbiota density in pH 5.8 treatment was significantly lower than that in pH 6.5 treatment (P<0.05). When pH was 5.2, the rumen microbiota density was the highest, which was significantly higher than that in the other treatments (P<0.05). 2) With the decrease of pH, the intracellular H+-ATPase activity in rumen microbiota was firstly increased and then decreased, but there was no significant difference among all treatments (P>0.05). 3) The intracellular ATP content in rumen microbiota was not significantly affected by different pH treatments (P>0.05). 4) With the decrease of pH, the intracellular protein content in rumen microbiota was gradually increased (P<0.05). 5) With the decrease of pH, the intracellular pH (pHi) and cellular transmembrane pH difference (ΔpH) in rumen microbiota were firstly increased and then decreased, and the pHi and ΔpH in pH 5.5 and 5.2 treatments were significantly higher than those in the other three treatments (P<0.05). 6) With the decrease of pH, the cell membrane permeability of rumen microbiota was gradually increased, except for pH 5.8 treatment, the other treatments were significantly higher than pH 6.5 treatment (P<0.05). In conclusion, the rumen microbiota can increase the intracellular H+-ATPase activity and protein content, consume ATP, and change pHi and ΔpH in response to external pH decline. When pH decreases to 5.5, the membrane permeability and pHi of rumen microbiota increase significantly, indicating that they are running to be subjected to more serious acid stress. The density of rumen microbiota fluctuates with the decrease of pH, and when pH decreases to 5.2, the density of rumen microbiota is the highest. © 2023 Authors. All rights reserved.     

Grassland quality response to climate change in Xinjiang and predicted future trends北大核心CSCD

Grassland is a major vegetation type in Xinjiang Province,and is an important component of carbon source-sink calculations. It is therefore important to ecological management decisions to understand the factors driving changes in grassland quality and likely future trends in those changes. We used geographic information maps to eliminate the interference of human activities and determine changes in grassland status and areas of stable grassland from 1980 to 2020,and analyzed changes in grassland quality and its response to climate change using data such as normalized vegetation index（NDVI）,vegetation net primary productivity（NPP）,and meteorological data,among others. We here estimate changes in grassland quality in Xinjiang and predict grassland quality changes from 2021 to 2040 using the Thornthwaite Memorial model and other models. We found that：1） The grassland quality in Xinjiang was generally increasing,with a statistically significant rate of ongoing increase. The grassland cover and quality in mountainous areas of Xinjiang was high,while that at the desert edge was low. 2）The main driving forces for grassland quality changes in Xinjiang are temperature and precipitation. The correlation between grassland quality and precipitation was positive. Temperatures exceeding a certain limit were found to inhibit grassland quality. Sensitivity to temperature and precipitation decline was found to be greater when vegetation cover was lower. 3）The grassland quality and its temporal and spatial changes in Xinjiang can be reflected by climatic productivity. The lower the grassland cover,the stronger was the link between grassland quality and climate factors. 4）Under currently predicted climate change scenarios,the quality of low-cover grassland will be improved in the future,while the quality of other categories will tend to decrease. This information on grassland quality in Xinjiang and its predicted future trends can assist in formulating ecological protection measures and in other ways,such as compilation of carbon stock inventories. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

Effect of Poly-β-Hydroxybutyrate on the Activity of Nonspecific Immunity Related Enzymes in Fenneropenaeus chinensis

[Objective] This study was carried out to explore the effect of poly-β-hydroxybutyrate(PHB) on the performance of the nonspecific immune system in Fenneropenaeus chinensis. [Method] F. chinensis individuals were assigned into six groups, and each group was fed with a diet containing 0(Control), 0.5%(Group E_(0.5)), 1.0%(Group E_(1.0)), 2.5%(Group E_(2.5)), 5.0%(Group E_(5.0)) or 10.0% PHB(Group E_(10.0)). The mortality rate and relative percent of survival(RPS) of each group were calculated after 6 weeks. Meanwhile, the total antioxidant capacity(T-AOC), the activity of acid phosphatase(ACP), peroxidase(POD) and catalase(CAT), and the content of malondialdehyde(MDA) in hepatopancreas and serum were measured,and their correlation with PHB concentration was analyzed. [Result] The RPS in PHB treated shrimps increased initially and decreased subsequently with increasing PHB concentration. RPS of Group E_(1.0) was the highest, showing significant difference from that of other groups( P 0.05).With the increase in PHB concentration, the activity of immunity related enzymes changed in a similar pattern with RPS: increasing at first and decreasing subsequently. In addition, the activity of the enzymes was elevated in the 2~(nd) and 3~(rd) weeks of PHB administration. Among them, T-AOC in serum of groups E_(1.0) and E_(2.5), T-AOC in hepatopancreas of Group E_(1.0), ACP activity in serum of groups E_(1.0) and E_(2.5), ACP activity in hepatopancreas of Group E_(1.0), CAT activity in groups E_(0.5), E_(1.0) and E_(2.5), CAT activity in hepatopancreas of groups E_(0.5), E_(1.0) and E_(10.0), POD activity in both serum and hepatopancreas of groups E_(0.5), E_(1.0) and E_(2.5), SOD activity in both serum and hepatopancreas of Group E_(1.0), MDA content in serum of Group E_(1.0) and MDA content in hepatopancreas of groups E_(0.5) and E_(1.0) showed significant difference from those of other groups(P0.05). [Conclusion] PHB can improve the immunity of F. chinensis, 1.0% in feed has the best effect, and the total enzyme activity reaches the highest level in the 2~(nd) and 3~(rd) weeks of PHB administration.     

Effects on Growth Performance and Feed Digestibility of Hainan Black Pigs by Adding Lysine in Low Protein Diet

[Objective] The paper was to study the effects on growth performance and feed digestibility of Hainan black pigs by adding lysine in low protein diet.[Method] A total of 36 Hainan black pigs with the body weight of(46.34 ±3.06) kg were randomly divided into three groups:control group(protein level 15%,lysine level 0.83%),experimental group I(protein level 13%,0.83%),and experimental group II(protein level 13%,lysine level 1.03),each group had three replicates of four pigs.The trial lasted 35 d.[Result] The growth performance of Hainan black pig in group II had no significant difference with that in control group(P0.05).The apparent digestibility of crude protein and phosphorus of Hainan black pigs in Group II increased significantly(P0.05),which were increased by 10.08% and 11.85% respectively compared to the control group;the apparent digestibility of calcium was increased,but the difference was not significant(P0.05).[Conclusion] It will not reduce the growth performance of Hainan black pig when the protein level of diet is reduced by 2% and the lysine level is increased to 1.03%.It is recommended that the diet can be used in the production of Hainan black pig.     

Changes in Chilled Chicken Quality and Correlation Analysis during Different Shelf Life

[Objective] The paper was to study the change rule and correlation analysis of quality indexes of chilled chicken within 7 d shelf life.[Method] Six pieces of fresh breast muscle were packaged in polyethylene(PE) food storage bags,labeled,and refrigerated at 4 ℃.The p H,water loss rate,tenderness,color value and inosinic acid content of chicken were measured at different time points of preservation(cold storage for 0,1,2,3,6,7 d).[Result] With the prolongation of shelf life,the p H of chilled chicken first increased then tended to be stable;the water loss rate first increased then stabilized;the shear force first decreased then increased.There was little difference in brightness value(L*) of chilled chicken dur-ing different shelf life(P0.05).The red degree value(a*) decreased with the prolongation of shelf life;the yellow degree value(b*) increased with the extension of shelf life.The inosinic acid content decreased with the prolongation of shelf life.The p H of chilled chicken in different shelf life had significant positive correlation with water loss rate(P0.05) and extremely significant negative correlation with shear force(P0.01).[Conclusion]The shelf life of 7 d has impact on meat color and inosinic acid of chilled chicken.Cold fresh preservation of chilled chicken should be less than 6 d;p H has certain correlation with water loss rate and shear force.