Impact of polyacrylamide supplementation on intake, nutrient digestion and growth of lambs.

This study was conducted to evaluate the effect of polyacrylamide (PAM) supplementation on the intake, digestion, weight gain, metabolism and growth of lambs. A total of ten 30 days old male small-tailed Han lambs with a body weight of 7.7±0.5 kg were divided into two equal groups (n = 5 each) and fed a basal diet or diet supplemented with 2.0 g of PAM per kg diet. The duration of the experiment was 210 days and experimental diets were fed ad libitum throughout the experimental period. Voluntary feed intake (VFI) was measured on daily basis, while body weight was measured on every ten days of the experiment.Two digestive and metabolic trials were conducted at the lamb's age of 95 to 103 days (Trial 1) and at the age of 210 to 218 days (Trial 2). At the end of experiment, all lambs were slaughtered to determine carcass characteristics. Results of the current study showed that supplementation of PAM in the diet of lambs increased the VFI and daily body gain by 14.4% (P < 0.05) and 15.2% (P < 0.01), respectively. In Trial 1, PAM supplementation in the diet increased the digestibility of dry matter (DM), organic matter (OM), crude protein (CP), cellulose, energy, and nitrogen retention by 7.9%, 5.4%, 6.4%, 9.6%, 4.3% and 30.3% (P < 0.01), respectively, and in Trial 2, PAM supplementation in the diet increased the digestibility of DM, OM, CP, cellulose, energy, and nitrogen retention by 9.3%, 7.9%, 7.7%, 11.6%, 6.9% and 38.5% (P < 0.01), respectively. Results of carcass parameter explored that supplementation of PAM in the diet increased the carcass, net meat and lean meat weights by 24.5%, 25.5%, and 30.6% (P < 0.01), respectively, however, PAM supplementation in the diet did not influence the contents of DM, OM, or CP in fresh liver, leg muscle, and rumen tissue; in addition, the CP contents in the Longissimus dorsi muscle was decreased by the supplementation of PAM in the diet. In summary, supplementation of 2.0 g of PAM per kg diet increased the VFI, nutrient digestibility, nitrogen retention, and carcass yield of lambs.

Characteristics of Aflatoxin B1 Degradation by Stenotrophomonas acidaminiphila and It's Combination with Black Soldier Fly Larvae.

Aflatoxin B1 (AFB1) is a common mycotoxin contaminant in cereals that causes severe economic losses and serious risks to the health of humans and animals. In this paper, we investigated the characteristics of AFB1 degradation by black soldier fly larvae (BSFL) combined with commensal intestinal microorganisms. Germ-free BSFL and non-sterile BSFL were reared on peanut meal spiked with AFB1 for 10 days. The result showed that germ-free BSFL and non-sterile BSFL could achieve 31.71% and 88.72% AFB1 degradation, respectively, which indicated the important role of larvae gut microbiota in AFB1 degradation. Furthermore, twenty-five AFB1-degrading bacteria were isolated from BSFL gut, and S. acidaminiphila A2 achieved the highest AFB1 degradation, by 94%. When S. acidaminiphila A2 was re-inoculated to BSFL, the detrimental effect of AFB1 on the growth performance of BSFL was alleviated, and complete AFB1 degradation in peanut meal was obtained. In conclusion, the present study may provide a strategy to degrade AFB1 in feedstuff through bioconversion with BSFL in combination with gut-originated AFB1-degrading bacteria, while providing a sustainable insect protein and fat source to animals.

Impact of docusate and fauna-free on feed intake, ruminal flora and digestive enzyme activities of sheep.

Four Small-tail Han male hogget sheep, fitted with rumen cannula and fed the same basal diet were used to study the impacts of docusate (DOC) and fauna-free on the voluntary feed intake (VFI), and ruminal protozoal, bacterial and fungal counts and the digestive enzyme activities. By a 4 × 4 Latin square design, sheep were given no DOC (the control), 2 doses of DOC: 1.2 and 3.0 g/kg diet or oral dose of 6.0 g/d DOC for three days (fauna-free treatment) in each period of 18 days, the last three days of which were for sampling the rumen fluid. Compared with the control, 1.2 g/kg of DOC supplementation significantly resulted in increases of 18.0% VFI and 44% bacterial count, and no significant change in the fungal number. Supplementing DOC reduced protozoal number in a dose-dependent manner. The fibre degradation enzyme activity in rumen fluid increased by 17.7% with a concomitant 10% increase in volatile fatty acids (VFA); the protease activity was reduced by 23% with a corresponding reduction in rumen ammonia by 42%. In contrast, supplementing 3.0 g/kg of DOC has adverse effects on those measures compared with 1.2 g/kg of DOC. Defaunation was accompanied with substantial increases in the bacterial and fungal counts, but had no significant influences on VFI and the enzyme activity for starch, protein and pectin digestion, and small changes in fibre digestion enzymes and the total VFA compared with the control. A high correlation (r2  = 0.82) was noted between VFI and the total activity of fibre digestion enzymes and VFA. It was proposed that fibre digestion rate in the rumen is a primary factor for determining VFI in sheep, and dietary supplementation of 1.2 g/kg of DOC could partially result in enhanced activity of fibre digestive enzyme in the rumen and increase VFI.

Development of an ultrasensitive aptasensor for the detection of aflatoxin B1.

Contamination of feed and food by aflatoxin B1 (AFB1), one of the most toxic of the mycotoxins, is a global concern. To prevent food safety scares, and avoid subsequent economic losses due to the recall of contaminated items, methods for the rapid, sensitive and specific detection of AFB1 at trace levels are much in demand. In this work, a simple, ultrasensitive, and reliable aptasensor is described for the detection of AFB1. An AFB1 aptamer was used as a molecular recognition probe, while its complementary DNA played a role as a signal generator for amplification by real-time quantitative polymerase chain reaction (PCR). Under optimal conditions, a wide linear detection range (5.0 × 10(-5) to 5.0 ng mL(-1)) was achieved, with a high sensitivity (limit of detection (LOD)=25 fg mL(-1)). In addition, the proposed aptasensor exhibited excellent specificity for AFB1 compared with eight other mycotoxins, with no obvious Ct value change. This aptasensor can also be used in quantifying AFB1 levels in Chinese wild rye hay samples and infant rice cereal samples, demonstrating satisfactory recoveries in the range of 88-127% and 94-119%, respectively. This detection technique has a significant potential for high-throughput, quantitative determination of mycotoxin levels in a large range of feeds and foods.

[Microsatellite analysis of genetic diversity and phylogenetic relationship of eight sheep breeds in Xinjiang].

To reveal the genetic diversity and syseighttemic relationship of main sheep breeds in north Xingjiang, the genetic polymorphisms of 10 microsatellites in 8 sheep breeds and one first filial generation (F1) in north Xinjiang were studied by means of PCR, polyacrylamide gel electrophoresis and silver staining. Number of alleles, average effective number of alleles (E) and average rates of homozygote of each breeds were counted. According to allele frequencies of ten microsatellites, polymorphism information content (PIC), mean heterozygosity (h) and genetic distances were calculated for each breeds. By using the Neighbor-joining method of Molecular Evolutionary Genetics Analysis software, a dendrogram was obtained based on genetic distances. Another dendrogram was obtained by Maximum Likelihood method in PHYLIP (3.6) software. The bootstrap values were evaluated for each crunode of the dendrogram by means of bootstrap test. The systemic relationship was analyzed as well. The results showed that 8 of 10 microsatellite loci were highly polymorphic, but BM1824 and MAF65 were low and medium polymorphic respectively, so the 8 microsatellite loci were effective markers for analysis of genetic relationship among sheep breeds. The average PIC (0.5631), h (0.5721) and E(2.9) of the whole population was all lower than those of other sheep breeds reported in the documents, which showed the gene polymorphisms and genetic diversity in these sheep breeds are relative rare. The genetic distances of native Aletai, Kazak and Bashibai sheeps in Xingjiang from foreign sheep breeds and cultivated breeds bearing foreign bloodline are relatively large. Consequently, they clustered in two groups. The phylogenetic relationship between different sheep breeds was in accordance with their resource, breeding history, differentiation and localities.