Animal Feed Science and Technology最新文献

A 60-day feeding trial was performed to optimize dietary protein based on the ideal protein concept for genetically improved farmed tilapia (GIFT) juveniles reared in inland saline water (ISW) of 10 ppt salinity. Seven heteronitrogenous (373.6–256.5 g crude protein/kg), isocaloric (∼ 16 MJ digestible energy/kg) and isolipidic (∼ 80 g lipid/kg) semi-purified feeds were formulated and prepared with decreasing levels of crude protein (CP), namely 373.6 (CP1), 352.2 (CP2), 334.5 (CP3), 314.9 (CP4), 293.7 (CP5), 275.2 (CP6) and 256.5 g/kg (CP7). The proportion of total essential and semi-essential amino acids was kept constant in all diets as ideal amino acid profiles and total non-essential amino acids were reduced linearly to reduce the dietary CP levels. Three hundred fifteen juveniles (average weight 4.76 ± 0.01 g) were randomly assigned into seven groups in triplicate. Fish of various groups were fed thrice daily at an apparent satiation level. The growth of juveniles increased linearly and quadratically (p<0.05) when the CP level of diets was decreased from 373.6 (CP1) to 334.5 g/kg (CP3), then declined linearly. The CP2 and CP3 groups had significantly higher feed intake and lower feed conversion ratio. In contrast, low CP-fed groups had superior protein utilization, viscerosomatic index and hepatosomatic index than other groups. The CP1 and CP2 groups had significantly higher whole-body protein and lower lipid content. The whole-body non-essential amino acid content diminished linearly (p<0.05) as dietary CP levels were decreased; the whole-body essential amino acid content remained unchanged (p>0.05). The high CP-fed juveniles (CP1 and CP2) showed a significantly (p<0.05) elevated protease activity, whereas the opposite trend was noticed for amylase activity. The aminotransferase activities of the liver and muscle were reduced linearly (p<0.05) with reduced dietary CP levels. Serum glucose and cholesterol contents elevated linearly (p<0.05) with decreased dietary CP levels. Whereas, the hemoglobin content and RBC count decreased (p<0.05) in the high CP-fed juveniles. The second-order polynomial regression analysis revealed that the optimal dietary CP levels could range from 311.1 to 318.0 g/kg for GIFT juveniles reared in ISW of 10 ppt salinity. Furthermore, by adopting the ideal protein concept, the CP levels in the diet of GIFT juveniles could be reduced from 373.6 to 311.1 g/kg without affecting growth performance. The outcome of this study will assist in developing a low-protein feed with balanced essential amino acids for GIFT culture in ISW.

Chinese herbal medicines (CHMs), known for their safety, low toxicity, and minimal impact on the environment, are often used as a natural feed additive in aquaculture to prevent or control diseases of aquatic animals. However, their effect on cell responses of Chinese soft-shelled turtle (Pelodiscus sinensis) remains unexplored. In this study, the extract mixed with four Chinese herbs of Astragalus membranaceus, Lycium barbarum, Rhizoma polygonati and Codonopsis pilosula in proportions (7:8:3:2) was used as a feed additive for 60 days to study their effects on the growth performance and immune response of P. sinensis in greenhouse mode. Results showed that the weight gain rate and the specific growth rate in the CHMs group were 46.63 % and 0.64 %, which were 1.13- and 1.15-fold of that in the control group, respectively. Besides, CHMs could significantly improve the survival rate by 76.94 % after artificial infection of Aeromonas hydrophila. The CHMs group also exhibited significant increases in the activities of total superoxide dismutase (27.76 %), catalase (41.28 %), glutathione peroxidase (14.62 %), and glutathione sulfur transferase (36.75 %) compared to the control group. Conversely, malondialdehyde concentration was reduced to 67.82 % of that in the control group. Moreover, the concentration of lysozyme and complement C3, as well as the activity of acid phosphatase, rose by 16.43 %, 24.30 %, and 27.68 %, respectively. Comparative transcriptome analysis revealed that growth, immunity, and lipid metabolism-related pathways are involved in the response to CHMs. Among these, the two pathways of the cell cycle and the cytokine-cytokine receptor interaction may play important roles in the growth and immunity of P. sinensis. SMOX, STAT3, and HMGCS1 may serve as key genes in CHMs-stimulated immune response in P. sinensis; GADD45B, ARG1, ACVR1C, and BMP7 may be crucial genes in promoting the growth of P. sinensis. This study provides a theoretical and practical basis for the green and efficient culture of P. sinensis.

An eight-week feeding trial was carried out to evaluate the impacts of dietary vitamin B₆ on growth performance, antioxidant capacity, carbohydrate metabolism, and lipid metabolism in Pacific white shrimp (Litopenaeus vannamei) under different carbohydrate levels. Six isonitrogenous and isolipid diets were formulated to contain two carbohydrate levels (15 % and 30 %) and three vitamin B₆ levels (0, 120 mg kg⁻¹ and 240 mg kg⁻¹). A total of 540 juvenile Pacific white shrimp (initial weight 1.15 ± 0.02 g) were randomized to six diets with three replicates, and each replication was stocked with 30 shrimp. The results suggested that dietary carbohydrate levels had no significant effect on percent weight gain (PWG) and specific growth rate (SGR), while PWG and SGR were significantly affected by dietary vitamin B₆ levels. The highest PWG and SGR appeared in the groups with 240 mg kg⁻¹ vitamin B₆ supplementation at different carbohydrate levels (P < 0.05). However, the interaction between vitamin B₆ and carbohydrate levels did not show significant differences in PWG and SGR (P > 0.05). Dietary vitamin B₆ and carbohydrates levels had a marked interaction in the content of glutathione (GSH) and concentration of malondialdehyde (MDA) in the hepatopancreas, and dietary vitamin B₆ observably increased the GSH content and decreased the concentration of MDA in 30 % carbohydrates (P < 0.05). Moreover, the contents of insulin-like peptide (INSL), crustacean hyperglycemic hormone (CHH), pyruvic acid (PA) and glucose, and the activities of phosphate fructose kinase (PFK) were markedly impacted by the interaction between dietary vitamin B₆ and carbohydrate levels. Vitamin B₆ supplementation could promote glucose transport, hepatopancreatic glycolysis, and insulin signaling pathway along with the degradation of glycogen in shrimp under high carbohydrate levels. Lipid metabolism results showed that dietary vitamin B₆ supplementation could increase lipid synthesis under 30 % carbohydrate diets. Overall, the finding indicated that vitamin B₆ supplementation could increase antioxidant capacity and regulate glucose metabolism by promoting carbohydrate degradation and lipid deposition in shrimp.

The availability of balanced diet is critical for reproductive success in fish. A feeding trial on Labeo catla females was carried out in earthen pond to assess the effect of different dietary protein to carbohydrate ratio on gonad maturation and breeding performance. Three feed D-I (Feed-I), D-II (Feed-II) and D-III (Feed-III) were formulated with varying ratio of Ground Nut Oil Cake (GNOC) and rice bran (2:1, 1:1 and 1:2) and fed for 120 days. To assess the gonad maturation events, GSI VSI, breeding, fatty acid analysis, sex hormone profiling, cholesterol, triglyceride and histological examinations were conducted. Fish groups fed with D-III exhibited the highest VSI and visceral fat (VF) deposition, followed by those fed with D-I, whereas groups fed with D-II showed significantly lower levels (P<0.05). The result of GSI was completely opposite to values of VSI. Ovarian histology showed less number of mature oocytes in D-I & D-III treatments and more mature oocytes in D-II. Breeding results showed that fishes fed with D-I and D-III hampered gonad maturation whereas fish fed with D-II responded towards spawning, fertilization, and hatching. Increased levels of testosterone, estradiol, and vitellogenin (Vtg) were observed in the D-II fed group whereas increased level of progesterone was observed in D-I fed group followed by D-II and D-III. Serum cholesterol was higher in the D-III and D-I group. Visceral fat accumulation prior to ovarian maturation is a normal phenomenon in this species which serves as a lipid reservoir required for the later transfer to the gonad as yolk or is utilized as an energy source for gonad maturation. However higher level of protein or carbohydrate in the diet disrupted normal gonad maturation and lead to abnormal visceral fat accumulation, sex steroid level, failure in spawning response and seed production.

A feeding trial was conducted to detect the optimal dietary protein requirement for ship sturgeon (Acipenser nudiventris) juveniles. Four isoenergetic diets were formulated to contain different protein levels i.e. 40 % (P40), 45 % (P45), 50 % (P50), and 55 % (P55). A total of 180 ship sturgeon juveniles, with an average weight of 63.5 ± 1.3 g, were randomly distributed into triplicated groups (15 fish per tank) and fed on the experimental diets for 10 weeks. Significant (P < 0.05) increases in growth indices and feed intake were noted with increasing dietary protein levels up to 50 % after which (P55) fish growth was declined. The highest values of protein and lowest value of lipids and ash contents were noted in the whole-body of fish fed on the P50 diet. The levels of red blood cells, hemoglobin, and hematocrit were markedly influenced (P < 0.05) by varying dietary protein concentrations, and the most elevated values were identified in the P50 treatment. Linear increases were observed in alanine aminotransferase and alkaline phosphate levels; while quadratic increases were observed in aspartate aminotransferase activities due to the increase in dietary protein levels. Quadratic increases in total protein (TP), total immunoglobulin (total Ig), and lysozyme (LYZ) were observed due to feeding the fish on higher protein levels. The highest level of TP was significantly (P < 0.05) found in P50 and P55 with no significant (P > 0.05) difference between them. Levels of total Ig and LYZ were significantly (P > 0.05) highest in the P50 treatment. Based on the regression fitting curves of growth indices, the optimum dietary protein level for ship sturgeon (A. nutiventis) juveniles is found to be 46.5 % – 50 %.

Data Availability

All data of this study are included in this article.

This study investigated the effect of preserving wheat and barley grains with an organic acid liquid surfactant mould inhibitor compared to conventional artificial drying and assessed its effects on the health and performance of pigs post-weaning (PW). A 2 × 2 factorial arrangement was conducted to investigate the interaction between grain preservation method (dried vs. preserved) and zinc oxide (ZnO) inclusion (yes vs. no) on growth performance, diarrhoea scores and incidence, and total tract nutrient digestibility. One hundred and ninety-two pigs (3 pigs/pen; 16 replicates/treatment) were assigned to one of four experimental diets for 35 days: (1) dried grain diet, (2) preserved grain diet, (3) dried grain diet with ZnO and (4) preserved grain diet with ZnO. Diets were formulated to contain similar levels of net energy and standardised ileal digestible lysine. On day 35 PW, 24 pigs (12 replicates/treatment) from the non-ZnO supplemented groups were euthanised and digesta was collected for coefficient of apparent ileal digestibility (CAID), gut microbial population and volatile fatty acid analysis. Stomach tissue was also collected for gene expression analysis, as well as small intestine samples for gut morphology. Notable improvements in grain quality were observed in the preserved grain, including a reduction in grain pH, mould presence, and contamination by mycotoxins, specifically deoxynivalenol in wheat and barley, and ochratoxin A and HT-2 toxin in barley. The preserved grain diet improved average daily gain (ADG; P < 0.01) and body weight (BW; P < 0.01) compared to the dried grain diet. The incorporation of ZnO increased average daily feed intake (ADFI; P < 0.01) and BW (P < 0.05) in the dried grain diet, however, ZnO did not affect ADFI (P > 0.05), and reduced ADG and BW in the preserved grain diet (P < 0.05). Pigs offered the preserved grain diet had reduced faecal scores and diarrhoea incidence compared to those offered the dried grain diet (P < 0.05). Supplementation of ZnO reduced faecal scores and diarrhoea incidence compared to non-supplemented pigs (P < 0.001). On day 35 PW, the preserved grain diet had improved CAID of nitrogen and gross energy (P < 0.05), lower levels of colonic branched-chain volatile fatty acids (P < 0.05), and beneficial shifts in gut microbial populations. Specifically, there was a reduction in ileal Streptococcus (P < 0.001) and an increased abundance of colonic Faecalibacterium (P < 0.05). In conclusion, organic acid preservation improved grain quality, benefiting post-weaned pigs through improved nutrient digestibility and gut health, thus enhancing overall growth performance PW.

Flaxseed meal is a highly nutritious feed resource rich in protein and unsaturated fatty acids. However, the presence of antinutritional factors such as cyanogenic glycoside limits its practical use. Fermentation has been demonstrated to degrade these antinutritional factors. However, little research has been conducted to investigate the effects of fermented flaxseed meal (FFSM) on the growth performance of growing pigs. This study thus aims to examine the effects of supplementing with 10 %, 15 %, and 20 % FFSM on the growth performance, immune function, and intestinal microbiota in growing pigs. Utilizing a completely randomized design, ninety-six growing pigs, each averaging 39.57 ± 0.63 kg, were allocated into four dietary groups with eight replicates per group and three pigs per replicate. The dietary treatments included: a control group (corn-soybean meal-based diet without FFSM) and basal diets supplemented with 10 %, 15 %, and 20 % FFSM. The trial lasted for 30 days. Results showed that including FFSM at 10 %, 15 %, and 20 % did not affect the average daily gain and average daily feed intake of pigs. However, the gain-to-feed ratio exhibited a linear decrease as the level of FFSM increased. Furthermore, FFSM supplementation linear increases neutral detergent fiber (inclusive of residual ash) and acid detergent fiber digestibility (P < 0.05). Investigating immune parameters and metabolites revealed a linear increase in immunoglobulins (IgA and IgM) and total bile acid in serum with increasing levels of FFSM supplementation (P < 0.05). Delving deeper into the gut microbiota’s complex ecosystem reveals that the quadratic response in Lactobacillus abundance and linear increase in Bacillus abundance (P < 0.05), while a linear and quadratic decrease in Clostridium_sensu_stricto_1 abundance with increasing FFSM addition (P < 0.05). Additionally, the concentrations of butyric acid and total short-chain fatty acids in feces changed quadratically with increasing proportions of FFSM (P < 0.05). The collective findings underscore the valuable role of microbial fermentation in enhancing the nutritional profile and utilization of flaxseed meal in the diets of growing pigs. Incorporation of FFSM not only augments the immune functionality of pigs but also ameliorates the balance of the intestinal microecology.

This study evaluated whether the incorporation of condensed tannin (CT) extract from Cistus ladanifer in lamb diets induces the same antioxidant protection as the C. ladanifer plant. How dietary CT can enhance the antioxidant status of animals and the oxidative stability of their products was also explored. Thirty-six lambs were used to evaluate the effect of three levels of C. ladanifer CT (without CT enrichment, medium, and high level of CT) and two ways of CT supply (C. ladanifer plant or C. ladanifer CT extract) on meat lipid and colour stability, and antioxidant status of muscle, rumen, abomasum, and faeces. The presence of CT monomers in muscle and CT content in digestive contents and faeces was evaluated. Cistus ladanifer plant and CT extract did not improve the lipid stability and antioxidant status of meat, but both CT sources enhanced the meat colour stability over storage time. Condensed tannin monomers were not identified in muscle. Intake of α-tocopherol decreased with inclusion of CT sources in diets. However, muscle α-tocopherol content was not affected by diets, suggesting that CT increase the α-tocopherol availability in muscle. Both CT sources increased antioxidant activity in the digestive contents, although, in the abomasum, C. ladanifer plant resulted in higher antioxidant activity than CT extract for the same CT level in the diet. No CT were detected in the faeces and both CT sources had a minor effect on the antioxidant activity, which could indicate the CT transformation in the gastrointestinal tract.

An experiment was conducted to determine coefficients of standardized total tract digestibility (CSTTD) of P in canola meal (CM) fed to gestating and lactating sows without or with a multi-enzyme complex (MC). Eight sows cannulated on day 40 of gestation were assigned at random to the 4 dietary treatments in a replicated 4 × 4 Latin square design. The 4 diets included 2 cornstarch-based diets with 313 g/kg solvent-extracted CM as the only source of P, without or with MC, a casein-cornstarch diet to determine ileal endogenous amino acid losses (amino acid digestibility data reported elsewhere), and a P-free diet to determine the endogenous P losses. All diets contained 3 g/kg titanium dioxide as an indigestible marker. Gestating sows were fed 3.0 kg/day, whereas, during lactation, sows had ad libitum access to diets. Samples were collected over 3 phases; mid-gestation, late-gestation, and lactation. Each phase had 4 experimental periods lasting 8 days. In each period, after 5-day acclimation to the experimental diets, fecal samples were collected by grab sampling via rectal palpation on day 6. Results indicated no differences in total tract digestibility of nutrients between mid-gestation, late-gestation, and lactation. Enzyme supplementation improved (P < 0.05) the apparent total tract digestibility of dry matter and P, and CSTTD of P during lactation. The CSTTD of P in CM was 0.445 (without MC) and 0.504 (with MC) in mid-gestation, 0.455 (without MC) and 0.492 (with MC) in late-gestation, and 0.442 (without MC) and 0.489 (with MC) in lactation. In conclusion, the average CSTTD for P in CM fed to sows was 0.447 and MC significantly improved the CSTTD of P in CM during lactation.