Enzymological, Histological and Serum Biomarkers Responses of Snubnose Pompano on Complete Replacement of Fishmeal Using Cottonseed Meal Supplemented With Lysine and Methionine in the Diet

In a feeding experiment, cottonseed meal (CSM) was used to replace fishmeal (FM) in the diet of snubnose pompano supplemented with lysine and methionine to assess the growth, nutritive profile, hematological, histological and stress biomarkers response. Experimental fishes were randomly stocked in five treatments each with triplicates. Five isonitrogenous and isolipidic diets with graded level of CSM (0, 8.7, 17.4, 26.0 and 34.7%) as replacement for FM protein (0, 25, 50, 75, and 100%) were formulated and fed to respective treatments. Comparison between various parameters among the treatments was made using orthogonal polynomial contrasts to indicate the statistical significance. Higher alkaline phosphatase, acid phosphatase, lactate dehydrogenase, malate dehydrogenase, aspartate and alanine aminotransferase activities were observed in 0CSM group and followed by 100CSM group as higher inclusion level of CSM with higher free gossypol content did not affect the metabolic enzyme activities. The maximum muscular free gossypol accretion of 1.28 mg kg-1 (on wet basis) was recorded in 100CSM group which was very well below the critical limit set by FDA. As a conclusion, fishmeal can be completely replaced using cottonseed meal in the diet of pompano without adverse effect on growth, metabolism and general health.

Effectiveness of the toxin-degrading strain screening strategy: Deficiency and improvement in screening the gossypol-degrading microorganism Aspergillus niger

The effectiveness of the classic screening strategy was verified, by duplicating and verifying the degradation of gossypol by the Aspergillus niger. It can reduce the free gossypol content through biosorption but has no effect on the total gossypol content and cannot effectively degrade gossypol. And the most interesting thing we found the strain can secrete agarase, utilise agar as carbon source. In this case, that will mislead researchers and lead them to make wrong judgments. That turns out the usual methods of previous screening strategies are not rigorous enough, the classic screening method has defect in screening toxin-degrading strain, so agar control group should be added. In this study, some suggestions are put forward to optimise the same type of experiments and broaden the idea of detoxification by microorganisms and provide reference for screening effective toxin-degrading microorganisms.

In situ rumen degradation characteristics and bacterial colonization of whole cottonseed, cottonseed hull and cottonseed meal with different gossypol content

Regarding whole cottonseed (WCS), cottonseed meal (CSM), and cottonseed hull (CSH), in situ rumen incubation was applied to determine their nutrient and gossypol degradation characteristics and bacterial colonization profile in lactating Holstein cows. Nylon bags containing the cotton by-products were incubated for 0, 6, 12, 24, 36, 48 and 72 h in the rumen, respectively. The relationship between nutrient degradability and free gossypol (FG) content were examined, and the differences in the composition and inferred gene function of the colonized microbiota were studied. As a result, CSM presented highest effective degradability of dry matter, neutral detergent fibre and acid detergent fibre, but the highest effective degradability of crude protein was found in WCS. Free gossypol disappearance rate increased significantly in the first 6 h, and it reached approximately 94% at 72 h of incubation among all samples. The level of FG did not affect nutrient degradability of cotton by-products. Significant differences were noted in attached bacterial community structure among cotton by-products after 24 h rumen incubation. Among the most abundant taxa at genus level, a greater abundance of Cercis gigantea and Succiniclasticum was observed in WCS samples, whereas the CSH and CSM samples contained a greater proportion of Prevotella 1 and Rikenellaceae RC9 gut group. The redundancy analysis revealed that the level of neutral detergent fibre, ether extract, and FG in cotton by-products were significantly positive related with the composition of the attached bacteria. Collectively, our results revealed the dynamics of degradation characteristics, and the difference in the composition of bacterial colonization. These findings are of importance for the targeted improvement of cotton by-products nutrient use efficiency in ruminants and further understanding of the gossypol degradation mechanism in the rumen.

Effects of Free Gossypol and Cyclopropenoid Fatty Acids Present in the Feed on the Productivity, Quality, Elasticity, and Microstructure of Hens’ Egg

BACKGROUND: Free gossypol (FG) and cyclopropenoid fatty acids (CPFAs) are two main natural toxins in cottonseed meal(CSM). The increased yolk elasticity under cold storage conditions is related to the excessive CSM in the feed. However, which toxin caused the increased yolk elasticity is still not clear. RESULTS: Our results show that the addition of FG or CPFA to the diet significantly reduced the egg production and feed conversion ratio. Besides, FG also resulted in a decrease in egg weight. The storage of eggs at 4 °C for four weeks resulted in a significant increase in elasticity and a decrease in the concentration of iron and calcium in the boiled yolks of CPFA and CSM groups when compared to the control. CPFA and CSM supplemented groups also showed an increase in pH and content of water in the yolk. Scanning electron microscopy (SEM) images from the CPFA and CSM groups revealed that the morphology of the vitelline membrane of eggs was characterized by different-sized holes. Furthermore, after four weeks of cold storage, the morphology of the vitelline granules in the CPFA and CSM supplemented groups were damaged; however, there were no significant alterations found in the FG group. CONCLUSION: The main cause of the “sponge-bob egg” effect was the presence of CPFA in cottonseed meal, which causes an increase in permeability of the vitelline membrane in eggs.

145 Inhibitory effects of gossypol on bovine in vitro embryo production

Cottonseed and its derivatives are frequently used in cattle feed as an effective dietary fibre supply and high protein and energy food source. However, the cotton plant contains gossypol, which in its free form induces male and female infertility. Therefore, this study aimed to evaluate the effect of gossypol supplementation on bovine in vitro embryo production. Ovaries were retrieved from slaughterhouses, and cumulus-oocyte complexes (COC) were recovered by follicular puncture. Based on free gossypol concentration present on the in vitro maturation, sperm capacitation, IVF and in vitro culture media, grades I, II and III COC (n=646) were divided in 3 treatments: 0μg mL−1 (control), 5μg mL−1 (G5) and 10μg mL−1 (G10). The COC were matured under a humidified atmosphere of 5% CO2 in air at 38.5°C for 24h in 90-μL droplets containing TCM-199 supplemented with 10% FCS, 0.2mM sodium pyruvate, LH, FSH, 75μg mL−1 amikacin, 17β-oestradiol. Each droplet corresponded to one replicate (n=14) and contained 15 to 18 COC. Matured COC and sperm were co-incubated in droplets (8-13 COC per 90μL) of TALP-IVF media supplemented with 6mg mL−1 BSA, 0.2mM sodium pyruvate, 30μg mL−1 heparin, 20 μM penicillamine, 10 μM hypotaurine, 1 μM epinephrine, 75μg mL−1 amikacin under a 5% CO2 humidified atmosphere at 38.5°C, for 20h. For IVF, non-sexed frozen-thawed semen was selected with Percoll® gradient. The resulting pellet was subjectively evaluated for motility and concentration and then diluted to final concentration of sperm mL−1 with fertilization medium. Presumptive zygotes were then cultured in 90-μL droplets of SOFaaci medium supplemented with 2.7mM myo-inosytol, 0.2mM pyruvate, 2.5% FCS (v/v), 5mg mL−1 BSA, 75μg mL−1 amikacin, and maintained for 8 days at 38.5°C in a humidified atmosphere with 5% CO2 in air. Cleavage, blastocysts production and hatching rates were evaluated at Days 3, 7 and 8, respectively. Data were submitted to ANOVA for parametric data and Wilcoxon test for non-parametric variables using the SAS software (SAS Institute Inc., Cary, NC, USA). Significance level was set at 5%. Cleavage rates of the control (81.05%) and G5 (71.85%) were higher compared with G10 (19.64%; P < 0.0001). Blastocyst production was lower in G5 (12.18%) compared with control (30.35%), and the addition of 10μg mL−1 of free gossypol (G10) completely inhibited embryo development (0%; P < 0.0001). As for the percentage of hatched blastocysts, the control (66.75%) had greater values compared with G5 (34.52%; P < 0.0001). Thus, the addition of 5 and 10μg mL−1 of free gossypol are extremely hazardous for in vitro bovine embryo development. Whether these deleterious effects take place in a similar fashion during in vivo embryo production remains to be investigated.