Effects of altering the ratio of C16:0 and cis-9 C18:1 in rumen bypass fat on growth performance, lipid metabolism, intestinal barrier, cecal microbiota, and inflammation in fattening bulls.

BACKGROUND: C16:0 and cis-9 C18:1 may have different effects on animal growth and health due to unique metabolism in vivo. This study was investigated to explore the different effects of altering the ratio of C16:0 and cis-9 C18:1 in fat supplements on growth performance, lipid metabolism, intestinal barrier, cecal microbiota, and inflammation in fattening bulls. Thirty finishing Angus bulls (626 ± 69 kg, 21 ± 0.5 months) were divided into 3 treatments according to the randomized block design: (1) control diet without additional fat (CON), (2) CON + 2.5% palmitic acid calcium salt (PA, 90% C16:0), and (3) CON + 2.5% mixed fatty acid calcium salt (MA, 60% C16:0 + 30% cis-9 C18:1). The experiment lasted for 104 d, after which all the bulls were slaughtered and sampled for analysis. RESULTS: MA tended to reduce 0-52 d dry matter intake compared to PA (DMI, P = 0.052). Compared with CON and MA, PA significantly increased 0-52 d average daily gain (ADG, P = 0.027). PA tended to improve the 0-52 d feed conversion rate compared with CON (FCR, P = 0.088). Both PA and MA had no significant effect on 52-104 days of DMI, ADG and FCR (P > 0.05). PA tended to improve plasma triglycerides compared with MA (P = 0.077), significantly increased plasma cholesterol (P = 0.002) and tended to improve subcutaneous adipose weight (P = 0.066) when compared with CON and MA. Both PA and MA increased visceral adipose weight compared with CON (P = 0.021). Only PA increased the colonization of Rikenellaceae, Ruminococcus and Proteobacteria in the cecum, and MA increased Akkermansia abundance (P < 0.05). Compared with CON, both PA and MA down-regulated the mRNA expression of Claudin-1 in the jejunum (P < 0.001), increased plasma diamine oxidase (DAO, P < 0.001) and lipopolysaccharide (LPS, P = 0.045). Compared with CON and MA, PA down-regulated the ZO-1 in the jejunum (P < 0.001) and increased plasma LPS-binding protein (LBP, P < 0.001). Compared with CON, only PA down-regulated the Occludin in the jejunum (P = 0.013). Compared with CON, PA and MA significantly up-regulated the expression of TLR-4 and NF-κB in the visceral adipose (P < 0.001) and increased plasma IL-6 (P < 0.001). Compared with CON, only PA up-regulated the TNF-α in the visceral adipose (P = 0.01). Compared with CON and MA, PA up-regulated IL-6 in the visceral adipose (P < 0.001), increased plasma TNF-α (P < 0.001), and reduced the IgG content in plasma (P = 0.035). Compared with CON, PA and MA increased C16:0 in subcutaneous fat and longissimus dorsi muscle (P < 0.05), while more C16:0 was also deposited by extension and desaturation into C18:0 and cis-9 C18:1. However, neither PA nor MA affected the content of cis-9 C18:1 in longissimus dorsi muscle compared with CON (P > 0.05). CONCLUSIONS: MA containing 30% cis-9 C18:1 reduced the risk of high C16:0 dietary fat induced subcutaneous fat obesity, adipose tissue and systemic low-grade inflammation by accelerating fatty acid oxidative utilization, improving colonization of Akkermansia, reducing intestinal barrier damage, and down-regulating NF-κB activation.

Effect of changing the proportion of C16:0 and cis-9 C18:1 in fat supplements on rumen fermentation, glucose and lipid metabolism, antioxidation capacity, and visceral fatty acid profile in finishing Angus bulls.

This study evaluated the effects of different proportions of palmitic (C16:0) and oleic (cis-9 C18:1) acids in fat supplements on rumen fermentation, glucose (GLU) and lipid metabolism, antioxidant function, and visceral fat fatty acid (FA) composition in Angus bulls. The design of the experiment was a randomized block design with 3 treatments of 10 animals each. A total of 30 finishing Angus bulls (21 ± 0.5 months) with an initial body weight of 626 ± 69 kg were blocked by weight into 10 blocks, with 3 bulls per block. The bulls in each block were randomly assigned to one of three experimental diets: (1) control diet without additional fat (CON), (2) CON + 2.5% palmitic calcium salt (PA; 90% C16:0), (3) CON + 2.5% mixed FA calcium salts (MA; 60% C16:0 + 30% cis-9 C18:1). Both fat supplements increased C18:0 and cis-9 C18:1 in visceral fat (P < 0.05) and up-regulated the expression of liver FA transport protein 5 (FATP5; P < 0.001). PA increased the insulin concentration (P < 0.001) and aspartate aminotransferase activity (AST; P = 0.030) in bull's blood while reducing the GLU concentration (P = 0.009). PA increased the content of triglycerides (TG; P = 0.014) in the liver, the content of the C16:0 in visceral fat (P = 0.004), and weight gain (P = 0.032), and up-regulated the expression of liver diacylglycerol acyltransferase 2 (DGAT2; P < 0.001) and stearoyl-CoA desaturase 1 (SCD1; P < 0.05). MA increased plasma superoxide dismutase activity (SOD; P = 0.011), reduced the concentration of acetate and total volatile FA (VFA) in rumen fluid (P < 0.05), and tended to increase plasma non-esterified FA (NEFA; P = 0.069) concentrations. Generally, high C16:0 fat supplementation increased weight gain in Angus bulls and triggered the risk of fatty liver, insulin resistance, and reduced antioxidant function. These adverse effects were alleviated by partially replacing C16:0 with cis-9 C18:1.

Altering the ratio of palmitic, stearic, and oleic acids in dietary fat affects nutrient digestibility, plasma metabolites, growth performance, carcass, meat quality, and lipid metabolism gene expression of Angus bulls.

This study evaluated the effects of changing the ratio of palmitic, stearic, and oleic acids in dietary fat on nutritional metabolism, growth performance, and meat quality of finishing Angus bulls. Bulls received the following three treatments: (1) a control diet without fat supplement (CON), (2) CON + mixed fatty acid supplement (58% C16:0 + 28% cis-9 C18:1; MIX), (3) CON + saturated fatty acid supplement (87% C16:0 + 10% C18:0; SFA). In summary, both fat treatment diets simultaneously increased saturated fatty acids C16:0 (P = 0.025), C18:0 (P < 0.001) and total monounsaturated fatty acids (P = 0.008) in muscle, thus balancing the ratio of unsaturated to saturated fatty acids in muscle. MIX diet increased the digestibility of dry matter (P = 0.014), crude protein (P = 0.038), and ether extract (P = 0.036). SFA diet increased the daily gain (P = 0.032) and intramuscular fat content (P = 0.043). The high content of C16:0 and C18:0 in the SFA diet promoted weight gain and fat deposition of beef cattle by increasing feed intake, up-regulating the expression of lipid uptake genes and increasing deposition of total fatty acids, resulting in better growth performance and meat quality.

Effects of Dietary Lysophospholipid Inclusion on the Growth Performance, Nutrient Digestibility, Nitrogen Utilization, and Blood Metabolites of Finishing Beef Cattle.

This study was conducted to evaluate the effect of dietary supplementation with lysophospholipids (LPLs) on the growth performance, nutrient digestibility, nitrogen utilization, and blood metabolites of finishing beef cattle. In total, 40 Angus beef bulls were blocked for body weight (447 ± 9.64 kg) and age (420 ± 6.1 days) and randomly assigned to one of four treatments (10 beef cattle per treatment): (1) control (CON; basal diet); (2) LLPL (CON supplemented with 0.012% dietary LPL, dry matter (DM) basis); (3) MLPL (CON supplemented with 0.024% dietary LPL, DM basis); and (4) HLPL (CON supplemented with 0.048% dietary LPLs, DM basis). The results showed that dietary supplementation with LPLs linearly increased the average daily gain (p < 0.01), digestibility of DM (p < 0.01), crude protein (p < 0.01), and ether extract (p < 0.01) and decreased the feed conversion ratio (p < 0.01). A linear increase in N retention (p = 0.01) and a decrease in urinary (p = 0.04) and fecal N (p = 0.02) levels were observed with increasing the supplemental doses of LPLs. Bulls fed LPLs showed a linear increase in glutathione peroxidase (p = 0.04) and hepatic lipase (p < 0.01) activity and a decrease in cholesterol (p < 0.01), triglyceride (p < 0.01), and malondialdehyde (p < 0.01) levels. In conclusion, supplementation with LPLs has the potential to improve the growth performance, nutrient digestibility, and antioxidant status of beef cattle.

Effects of supplementation with lysophospholipids on performance, nutrient digestibility, and bacterial communities of beef cattle.

An experiment was conducted to investigate the influences of supplemental lysophospholipids (LPL) on the growth performance, nutrient digestibility, and fecal bacterial profile, and short-chain fatty acids (SCFAs) of beef cattle. Thirty-six Angus beef cattle [565 ± 10.25 kg body weight (BW)] were grouped by BW and age, and randomly allocated to 1 of 3 treatment groups: (1) control (CON, basal diet); (2) LLPL [CON supplemented with 0.5 g/kg LPL, dry matter (DM) basis]; and (3) HLPL (CON supplemented with 0.75 g/kg, DM basis). The Angus cattle were fed a total mixed ration that consisted of 25% roughage and 75% concentrate (dry matter [DM] basis). The results reveal that LPL inclusion linearly increased the average daily gain (P = 0.02) and the feed efficiency (ADG/feed intake, P = 0.02), while quadratically increasing the final weight (P = 0.02) of the beef cattle. Compared with CON, the total tract digestibilities of DM (P < 0.01), ether extract (P = 0.04) and crude protein (P < 0.01) were increased with LPL supplementation. At the phylum-level, the relative abundance of Firmicutes (P = 0.05) and ratio of Firmicutes: Bacteroidetes (P = 0.04) were linearly increased, while the relative abundances of Bacteroidetes (P = 0.04) and Proteobacteria (P < 0.01) were linearly decreased with increasing LPL inclusion. At the genus-level, the relative abundances of Clostridium (P < 0.01) and Roseburia (P < 0.01) were quadratically increased, and the relative abundances of Ruminococcus was linearly increased (P < 0.01) with LPL supplementation. Additionally, increasing the dose of LPL in diets linearly increased the molar proportion of butyrate (P < 0.01) and total SCFAs (P = 0.01) concentrations. A conclusion was drawn that, as a promising feed additive, LPL promoted growth performance and nutrient digestibility, which may be associated with the change of fecal microbiome and SCFAs.

Effects of waste milk feeding on rumen fermentation and bacterial community of pre-weaned and post-weaned dairy calves.

The objective of this study was to investigate the effect of waste milk with antibiotic residue on rumen fermentation and rumen bacterial composition of dairy calves during pre-weaned and post-weaned periods. A total of 24 Holstein male calves (43.4 ± 0.93 kg body weight, mean ± standard error) were allocated into four blocks based on birth date. Dairy calves were supplied 100% milk replacer (MR, n = 8), 50% milk replacer mixed with 50% waste milk (MM, n = 8), or 100% waste milk (WM, n = 8). Ruminal samples were collected at 49 and 63 days of age and then subjected to determinations of pH value, volatile fatty acids (VFA), ammonia nitrogen (NH3-N) and 16S rRNA gene amplicon sequencing. The results showed that feeding WM had no effect on the pH value, the concentrations of VFA (acetic acid, propionic acid, butyric acid, isovaleric acid, valeric acid), and NH3-N in dairy calves compared to feeding MR. However, from 49 to 63 days of age, the pH value (p < 0.001) was significantly increased, while the levels of total VFA (p = 0.004), acetic acid (p = 0.01), propionic acid (p = 0.003) and valeric acid (p < 0.001) were significantly decreased. For rumen microorganisms, there was no differences in bacterial diversity among the treatments. But the relative abundance of Veillonellaceae was significantly lower (p = 0.05) in the calves fed WM than that from MR group at 49 days of age; however, no difference was detected at 63 days of age. Feeding WM to calves tended to reduce family Veillonellaceae and genus Olsenella in the rumen at 49 days of age (p = 0.049). Analysis of temporal changes in rumen bacteria based on alpha-diversity and beta-diversity as well as the microbial relative abundances did not exhibit any difference. In addition, relative abundances of Clostridia_UCG-014, Prevotella, Syntrophococcus, Eubacterium_nodatum_group, Pseudoramibacter and Solobacterium were correlated with rumen pH value and the concentrations of TVFA, propionic acid, isovaleric acid, valeric acid and NH3-N. In conclusion, compare to MR, calves supplied with WM had little changes on the rumen pH value, NH3-N or VFAs contents. Additionally, limited effects could be found on rumen microbiota in the calves fed WM. However, further studies needed to explore if there exist any long-term effects of early-life rumen microbiota modulation on dairy cows.

Novel prefractionation method can be used in proteomic analysis.

For the first time, a novel prefractionation method used in proteomic analysis was developed, which is performed by a novel aqueous two-phase system (NATPS) composed of n-butanol, (NH(4))(2)SO(4), and water. It can separate proteomic proteins into multigroups by one-step extraction. The phase-separation conditions of n-butanol solutions were studied in the presence of commonly used inorganic salts. The NATPS was subsequently developed. Using human serum albumin, zein, and gamma-globulin as model proteins, the separation effectiveness of the NATPS for protein was studied under affection factors, i.e., pH, n-butanol volume, protein, or salt concentration. The model and actual protein samples were separated by the NATPS and then directly used for gel electrophoresis without separating the target proteins from phase-forming reagents. It revealed that the NATPS could separate proteomic proteins into multigroups by one-step extraction. The NATPS has the advantages of rapidity, simplicity, low cost, biocompability, and high efficiency. It need not separate target proteins from the phase-forming reagents. The NATPS has great significance in separation and extraction of proteomic proteins, as well as in methodology.

Multilayer films of carbon nanotubes and redox polymer on screen-printed carbon electrodes for electrocatalysis of ascorbic acid.

Multilayer films containing multiwall carbon nanotubes and redox polymer were successfully fabricated on a screen-printed carbon electrode using layer-by-layer (LBL) assembled method. UV-vis spectroscopy, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy and electrochemical method were used to characterize the assembled multilayer films. The multilayer films modified electrodes exhibited good electrocatalytic activity towards the oxidation of ascorbic acid (AA). Compared with the bare electrode, the oxidation peak potential negatively shifted about 350mV (versus Ag/AgCl). Furthermore, the modified screen-printed carbon electrodes (SPCEs) could be used for the determination of ascorbic acid in real samples.

A sensitive method for the detection of proteins by high-efficiency fluorescence quenching.

A successful method for the detection of electron transfer proteins such as cytochrome c, hemoglobin and myoglobin has been developed based on the fluorescence quenching of semiconductor nanocrystals. High sensitivity and a good linear relationship are obtained.