Lower Feed Efficiency Research Articles

In vitro ruminal fermentation of treated alfalfa silage using ruminal inocula from high and low feed-efficient lactating cows

To assess the effect of two additives on alfalfa silage and on invitro ruminal fermentation when using ruminal inocula from high feed-efficient (HE) and low feed-efficient (LE) lactating cows. First- and second-cut alfalfa was harvested at 40% bloom stage, treated with control (no additive), Lactobacillus plantarum (LP) or formic acid (Formic), ensiled in 1·0l minisilos, and fermented for 60days. Fermented alfalfa was incubated invitro for 24h using ruminal inoculum from HE and LE lactating cows. The pH was lower in alfalfa silage treated with LP and Formic, and produced lower ammonia-N than did the control. In vitro true dry matter digestibility (IVTDMD) was higher with ruminal inoculum from HE than LE cows, but there was no consistent effect of treated alfalfa on microbial biomass yield and invitro volatile fatty acids. The IVTDMD was numerically greater with ruminal inoculum from higher feed-efficient cows although statistical significance was only demonstrated with the first-cut alfalfa. However, treated alfalfa silage did not show the effect expected on invitro microbial biomass yield. The feed efficiency of cows used as a source of ruminal inocula may affect IVTDMD and be a source of variation across invitro runs. Differences in ruminal fermentation between cows of different feed efficiency could help to explain differences in milk yield and other parameters of dairy cattle performance.

Effects of dietary carbohydrate-to-lipid ratio on the growth performance and feed utilization of juvenile turbot (Scophthalmus maximus)

A 9-week feeding trial was conducted to investigate the effects of dietary carbohydrate to lipid ratio (CHO:LIP) on the growth performance and feed utilization of juvenile turbot Scophthalmus maximus (initial body weight 8.75 g ± 0.04 g). Four isonitrogenous and isoenergetic low protein level (39%) diets were formulated with increasing ratios of dietary carbohydrate to lipid (2:18, 6:18, 18:12 and 28:6). A high protein level (50%) diet with the 2:12 ratio of carbohydrate to lipid was used as the control. Results showed that the survival rate, contents of moisture, crude protein and ash in muscle were not significantly affected by dietary treatments. With the dietary CHO:LIP ratio increased from 2:18 to 18:12, weight gain rate significantly increased (P < 0.05). Higher dietary CHO:LIP ratio (28:6) resulted in the significantly decreased weight gain rate (P < 0.05). Meanwhile, this treatment also resulted in the highest daily feed intake and liver glycogen content, as well as the lowest feed efficiency (P < 0.05). Muscle glycogen content in fish fed the diet with 2:12 or 2:18 CHO:LIP ratio was significantly lower than those fed with the other three diets (P < 0.05). The present results confirmed that the juvenile turbot can utilize carbohydrate. Furthermore, the appropriate ratio of dietary carbohydrate to lipid was important to the growth and feed utilization of turbot. The proper CHO:LIP ratio based on the growth performance in the present study was determined to be 18:12 when the dietary protein level was 39%.

Effects of seaweed replacement by hydrolyzed soybean meal on growth, metabolism, oxidation resistance and body composition of sea cucumber Apostichopus japonicus

A feeding trial was conducted to assess effects of seaweed replacement by hydrolyzed soybean meal (HSBM) on growth performance, diet utilization, metabolism and body composition of sea cucumber Apostichopus japonicus. Six iso-energetic (11.39±0.08kJ/g) and isoprotein (13.62±0.05g/kg) diets were formulated by replacing 0%, 20%, 40%, 60%, 80% and 100% seaweed protein with graded HSBM levels of 0%, 4.09%, 8.18%, 12.27%, 16.36% and 20.45%. The seventh diet (S12.27%) used 12.27% soybean meal (SBM) instead of 12.27% HSBM. Triplicate tanks (40 sea cucumber per tank) were fed one of seven diets for 45days. The results showed that growth performance of sea cucumber increased with the increase of HSBM levels from 4.09% to 12.27% while decreased as the HSBM level increased to 20.45% (P<0.05). Sea cucumber fed diets with HSBM level from 8.18 to 16.36% have higher daily feeding intake (P<0.05), while those fed diet with HSBM level of 20.45% have lower feed efficiency compared with the control treatment (P<0.05). Apparent digestibility coefficients of dry material and crude protein of sea cucumber fed diets with HSBM levels from 8.18% to 20.45% were significantly higher than that of control group (P<0.05). High inclusion of HSBM (16.36% and 20.45%) significantly reduced intestine-body wall ratio, and moderate to high HSBM levels (8.18–20.45%) reduced viscera-body wall ratio and intestine-viscera ratio (P<0.05). Alkaline protease activity was elevated by dietary addition of HSBM at level of 8.18% but suppressed at level of 20.45% (P<0.05). Amylase activity was also elevated significantly by addition of HSBM levels from 12.27% to 20.45% (P<0.05). Intestinal glutamic-pyruvic transaminase (GPT) and glutamic-oxaloacetic transaminase (GOT) activities significantly increased in sea cucumber fed diets with HSBM levels from 4.09% to 12.27% but GPT activity of intestine and body wall decreased in those fed diets with HSBM levels from 16.36% to 20.45% compared with the control group (P<0.05). Intestinal superoxide dismutase (SOD) activity increased in sea cucumber fed diets with HSBM levels from 8.18% to 12.27% (P<0.05), but the activities of SOD and glutathione peroxidase of body wall showed significant declines at high HSBM levels (16.36% and 20.45%) (P<0.05). The contents of Ash, Mg, Ca, Zn and Se of body wall significantly increased in sea cucumber fed diet with HSBM level of 8.18% (P<0.05). Fe content of body wall significantly increased in sea cucumber fed diets with HSBM level from 12.27% to 20.45%. Sea cucumber fed diet with 12.27% HSBM have inferior growth performance, diet utilization, oxidation resistance and metabolism compared those fed diet with 12.27% SBM (P<0.05). Present study indicated that sea cucumber could utilize effectively HSBM as a seaweed powder replacer. Based on growth performance, we can conclude that the optimum dietary levels of HSBM for sea cucumbers is 8.03–8.15% (replacing 39.25–39.86% seaweed). Statement of relevanceOur paper provided an idea of optimizing the feed formula of sea cucumber by adding hydrolyzed soybean meal in sea cucumber culture. This optimized formula could improve diet utilization and promote growth of sea cucumber. More importantly, replacement of seaweed powder with hydrolyzed soybean meal could reduce the use of seaweed powder due to unstable supply and increased price.

(An) orexigenic hypothalamic neuropeptides are differentially expressed in high and low feed efficient quail lines

The livestock and poultry industry is facing numerous challenges to keep up with the increasing demand for high quality animal protein due to the continuously increasing global human population, severe drought conditions around the world, and grains being used for ethanol production. Since feed costs are the majority of the total cost required to produce a live bird, feed efficiency (FE) is a trait of importance. It is beneficial to develop a more deep molecular understanding of the mechanisms that determine feed efficiency. Recently, this study used Japanese quail that were divergently selected for high and low feed efficiency as a model to determine the differential expression of several feeding-related hypothalamic neuropeptides.

Evaluation of coffee ground as a feedstuff in practical diets for olive flounder Paralichthys olivaceus

A 10-week feeding trial was carried out to investigate the feasibility of using spent coffee ground (CG) as a potential feed ingredient for olive flounder. Growth, feed utilization, body composition and antioxidant enzyme activity were examined. A control diet was formulated and three other diets were prepared to contain 5, 10 or 15% CG (designated as Con, CG5, CG10 and CG15, respectively) by replacing for wheat flour. At the end of the feeding trial, fish fed the CG5 diet exhibited significantly (P <0.05) higher growth performance than those fed the control diet. Also, fish fed the CG10 diet had a comparable growth to that of the control group, but further increase of dietary CG inclusion level to 15% resulted in significant decrease of growth performance. Fish fed the CG15 diet showed significantly lower feed efficiency and protein efficiency ratio than other treatments. Significantly lower muscle protein content was observed in fish fed CG15 diet compared to the control. Significant reduction in plasma cholesterol concentration was found in fish fed CG15 diet compared to control. No significant changes were found in alkyle and superoxide radicals scavenging activities of plasma, muscle and liver among dietary treatments. Also, liver total protein, total antioxidant capacity, catalase and glutathione peroxidase activities were not significantly influenced by dietary inclusion of CG. According to these results, we concluded that CG can be included up to 10% in the diet for olive flounder without any adverse effects on growth, feed utilization and antioxidant enzyme activity.

Nursery performance of Pacific white shrimp (Litopenaeus vannamei Boone, 1931) cultivated in a biofloc system: the effect of adding different carbon sources

Effect of different carbon sources on nursery performance of Pacific white shrimp (Litopenaeus vannamei) cultivated in biofloc system was investigated. Shrimp postlarvae (98.47 ± 8.6 mg) were fed for 32 days in tanks with water volume of 130 L and density of 1 individual L−1. One control treatment and four biofloc treatments (BFT1, BFT2, BFT3 and BFT4) with adding different carbon sources including molasses, starch, wheat flour and mixture of them, respectively, were considered at equal weight ratios. According to the results, salinity, dissolved oxygen and pH were not significantly different among the biofloc treatments (P > 0.05). Maximum pH (8.27) and maximum dissolved oxygen (6.35 mg L−1) were recorded in the control. Maximum (0.43 mg L−1) and minimum (0.09 mg L−1) ammonia were recorded in the control and BFT2, respectively (P < 0.05). Using simple carbohydrates (molasses and starch) lowered the ammonia concentration significantly. The highest increase in body weight (1640.43 ± 231.28 mg), growth rate, specific growth rate (8.97 ± 0.42% per day) and biomass (190.29 ± 26.83 mg) were found in BFT1 and the highest survival (90 ± 0.77%) was found in BFT4. The highest feed conversion (1.52 ± 0.23) and the lowest feed efficiency (66.81 ± 7.95) were observed in the control (P < 0.05). The proximate composition analysis revealed an increase in lipid and ash in biofloc treatments. Results indicated that using biofloc technology with zero-water exchange system and adding carbon sources could help to recycle waste and improve the water quality. Moreover, the type of carbonaceous organic matter as a substrate for heterotrophic bacteria would be effective in degradation and metabolization of ammonia and nitrite.

Effects of Ambient Temperature on Growth Performance, Blood Metabolites, and Immune Cell Populations in Korean Cattle Steers.

Exposure to cold may affect growth performance in accordance with the metabolic and immunological activities of animals. We evaluated whether ambient temperature affects growth performance, blood metabolites, and immune cell populations in Korean cattle. Eighteen Korean cattle steers with a mean age of 10 months and a mean weight of 277 kg were used. All steers were fed a growing stage-concentrate diet at a rate of 1.5% of body weight and Timothy hay ad libitum for 8 weeks. Experimental period 1 (P1) was for four weeks from March 7 to April 3 and period 2 (P2) was four weeks from April 4 to May 1. Mean (8.7°C) and minimum (1.0°C) indoor ambient temperatures during P1 were lower (p<0.001) than those (13.0°C and 6.2°C, respectively) during P2. Daily dry matter feed intake in both the concentrate diet and forage groups was higher (p<0.001) during P2 than P1. Average daily weight gain was higher (p<0.001) during P2 (1.38 kg/d) than P1 (1.13 kg/d). Feed efficiency during P2 was higher (p = 0.015) than P1. Blood was collected three times; on March 7, April 4, and May 2. Nonesterified fatty acids (NEFA) were higher on March 7 than April 4 and May 2. Blood cortisol, glucose, and triglyceride concentrations did not differ among months. Blood CD4+, CD8+, and CD4+CD25+ T cell percentages were higher, while CD8+CD25+ T cell percentage was lower, during the colder month of March than during May, suggesting that ambient temperature affects blood T cell populations. In conclusion, colder ambient temperature decreased growth and feed efficiency in Korean cattle steers. The higher circulating NEFA concentrations observed in March compared to April suggest that lipolysis may occur at colder ambient temperatures to generate heat and maintain body temperature, resulting in lower feed efficiency in March.

Evaluation of Smoked Skipjack Processing Byproduct Meal as an Alternative Feed Ingredient for Juvenile Humpback Grouper Cromileptes altivelis

This study aimed to evaluate the utilization of smoked skipjack processing byproduct meal (SPBM) to reduce the use of fish meal (FM) for juvenile humpback grouper Cromileptes altivelis. This study consisted of digestibility test of SPBM and biological test to observe growth performance. Five isonitrogenous and isocaloric experimental diets were used: Diet A contains 0% SPBM as a control diet, and diets B, C, D, and E contain 25%, 50%, 75%, and 100% of SPBM protein to substitute FM, respectively. Digestibility trial was performed for 14 days by adding Cr2O3 into the experimental diets and collecting fecal matter 40–60 minutes after each feeding. For growth trial, juvenile humpback grouper were kept in glass aquariums and fed by the experimental diet until apparent satiation for 60 days. Our result shows that the dry matter and protein SPBM apparent digestibility coefficient is lower compared to FM. The fish that was fed with diet B and C performed a comparable specific growth rate, feed efficiency, and protein retention compared to control (p > 0.05). However, lower specific growth rate, feeding efficiency, and protein retention were observed in fish that was fed with diet D (75% SPBM) and diet E (100% SPBM; p < 0.05). These results indicate that up to 50% of smoked SPBM can be used for the diet of humpback grouper.

Differential expression of feeding-related hypothalamic neuropeptides in the first generation of quails divergently selected for low or high feed efficiency

Livestock and poultry sectors are facing a combination of challenges, including a substantial increase in global demand for high quality animal protein, general droughts and steady rise in animal feed cost. Thus feed efficiency (FE), which defines the animal's ability to convert feed into body weight, is a vital economic and agricultural trait. Genetic selection for FE has been largely used in chickens and has been applied without knowledge of the underlying molecular mechanisms. Although it has made tremendous progress (breast yield, growth rate, egg production), there have been a number of undesirable changes such as metabolic disorders.In the present study we divergently selected male and female quail for high and low FE and we aimed to characterize the molecular basis of these differences at the central level, with the long-term goal of maximizing FE and avoiding the unfavorable consequences.The FE phenotype in first generation quails seemed to be achieved by reduced feed intake in female and increased body weight gain in males. At the molecular level, we found that the expression of feeding-related hypothalamic genes is gender- and line-dependent. Indeed, the expression of NPY, POMC, CART, CRH, melanocortin system (MC1R, MC2R, MC4R, MC5R), ORX, mTOR and ACCα was significantly decreased, however ORXR1/2, AMPKα1, S6K1 and STAT1, 5 and 6 were increased in high compared to low FE males (P<0.05). These genes did not differ between the two female lines. ADPN gene expression was higher and its receptor Adip-R1 was lower in LFE compared to HFE females (P<0.05). In male however, although there was no difference in ADPN gene expression between the genotypes, Adip-R1 and Adip-R2 mRNA abundances were higher in the LFE compared to HFE line (P<0.05).This study identified several key central feeding-related genes that are differentially expressed between low and high FE male and female quails which might explain the differences in feed intake/body weight gain observed between the two lines. Of particular interest, we provided novel insights into central AMPK–mTOR–ACC transcriptional differences between low and high FE quail which may open new research avenues on their roles in the regulation of energy balance and FE in poultry and livestock species.

Short communication: Effect of canola meal use as a protein source in a starter mixture on feeding behavior and performance of calves during the weaning transition

The aim of this study was to determine the effect of canola meal use as a protein source in a starter mixture (SM) on feeding behavior and performance of calves during weaning transition. A total of 36 female Holstein calves of a mean age 14.9±1.6d and body weight 40.1±4.2kg (mean ± SD) were allocated to 1 of 3 treatments differing in the main source of protein for the SM (12 calves per treatment): (1) soybean meal (TSBM); (2) soybean meal and canola meal (TSBM/TCM); and (3) canola meal (TCM). The SM was offered for ad libitum consumption beginning on the first day of the study, whereas milk replacer (MR) was fed in amounts equal to 900g (as fed) per day from d 1 to 35 and 450g/d from d 36 to 42 of the study. Calves were completely weaned on d 43 of the study (57.9±1.6d of age; mean ± SD), and their performance was monitored for an additional 2 wk. Calf body weight was recorded weekly, and MR and SM intake and fecal fluidity were recorded daily. Feeding behavior of calves during weaning transition, including frequency (no./d), time (min/d), and rate (g/min) of eating the SM as well as frequency and time of drinking water, was monitored on 6 calves per treatment for 2 consecutive days before MR step-down (d 34–35), at MR step-down (d 41–42), and after weaning (d 48–49 of study). Starter mixture intake tended to be higher for TSBM calves as compared with TSBM/TCM calves from d 1 to 35 of the study but was not different between TSBM and TCM calves and was not different between treatments in the whole study period. Calves from TCM treatment had reduced average daily gain (ADG) and feed efficiency (g of ADG/kg of dry matter intake) and a higher fecal score in the period from d 1 to 35 of the study and had lower feed efficiency and tended to have lower ADG in the whole study period as compared with TSBM calves. Average daily gain and feed efficiency did not differ between TSBM and TSBM/TCM calves. Frequency of eating the SM and drinking water as well as time and rate of eating the SM and time of drinking water did not differ between treatments. It is concluded that presence of canola meal in a SM does not affect feeding behavior and performance of calves during weaning transition but has a negative effect on ADG, feed efficiency, and number of days with diarrhea during the preweaning phase of rearing.

Synchronization of Protein and Energy Supply in the Rumen to Improve Low Quality Feed Efficiency

Agricultural by-products which can be used as source of roughage, have some limitations as they contain low crude protein and low dissolved organic material and high crude fiber. Synchronization of nutrients through supplementation can provide a positive effect on microbial protein synthesis, especially on ruminants fed low quality forage. Contribution of protein from rumen microbes is essential for feed management based on agricultural by product. Microbial protein can supply 70-100% of the total protein available for ruminants fed low quality feed. Microbial protein has amino acid profile which is ideal to meet ruminant’s requirement. This paper describes synchronization of protein and energy supply in the rument that has been applied by several countries. Application of this synchronization in Indonesia is still limited on: (1) Arranging the use of feedstuffs through the ratio of forage and concentrate; (2) Supplementation of protein and energy sources; and 3) Feeding frequency regulation. The application of synchronization through the use of feed ingredients based on degradation level and its index value is still limited due to lack of data on protein and energy degradation of feed ingredients used in Indonesia. Therefore, the information on the degradation value of protein and energy of feed ingredients in Indonesia is necessary in order to optimize the use of low quality feed ingredients.

Effect of phosphorus supplementation on cell viability, anti-oxidative capacity and comparative proteomic profiles of puffer fish (Takifugu obscurus) under low temperature stress

The aim of this study was to investigate the effects of dietary phosphorus (P) on the growth and response of obscure puffer under low temperature stress. Six diets were supplemented with graded levels (0, 0.2, 0.4, 0.6, 0.8, 1.2%) of P from Monocalcium phosphate. The analyzed total P contents of the six diets were 0.40, 0.60, 0.81, 0.98, 1.19 and 1.55% respectively. The results showed fish fed diets supplemented with 0 and 0.2% P had significantly lower weight gain, feed efficiency and feed intake than fish fed diets supplemented with 0.6, 0.8 and 1.2% P. After the 8-week feeding trial, puffer fish were exposed to acute low temperature challenge (12±2°C) and sampled at different time points (0, 3, 6, 12, 24, 48h). The blood cell numbers were significantly higher in fish fed diets supplemented with 0.6, 0.8 and 1.2% P than in fish fed diets without P supplement at 6, 12, 24 and 48h. The highest rate of viable blood cells was observed in fish fed diets supplemented with 0.6 or 0.8% P at 3 and 6h. At 6, 24 and 48h, the respiratory burst activities tended to decrease with increasing dietary P supplement up to 0.6, 1.2 or 0.8%, respectively. At 12, 24 and 48h, plasma CAT activity increased with increasing dietary P supplement up to 0.8%. The highest plasma SOD activity was in fish fed diets supplemented with 0.6 and 0.8% P at 6h. At 3, 6, 12, 24 and 48h, liver GPx activity increased significantly with the increase of dietary P supplement, and GPx activity in the 0.8% feed group achieved the highest. Fish fed diet without P supplement showed the highest plasma MDA level at 3h and 6h, highest liver MDA level at 12h and 24h. Two-dimensional electrophoresis proteomic approach was used to investigate altered proteins between P deficient (P=0) and adequate (P=0.8%) group in liver of puffer fish during cold stress treatment. MALDI-TOF/TOF MS analysis revealed that adequate P diet significantly up-regulated three energy generation related enzymes (ribose-5-phosphate isomerase-like 5, ribulose-phosphate 3-epimerase-like and alpha-enolase-like isoform 2) and two lipid transport proteins (ApoA-I and FABP), and down-regulated an intermediate filament protein (keratin type I cytoskeletal 13-like) of puffer fish during cold stress. These results clearly indicated that dietary P supplement could improve cell viability, anti-oxidative capacity, energy generation and lipid transportation of puffer fish under cold stress. Statement of relevanceThis study indicates that dietary P improved cell viability, anti-oxidative capacity, energy generation and lipid transportation of puffer fish under cold stress. The results will contribute to our understanding of the role of phosphorus metabolism in aquatic animals.

A dietary two-generation reproductive toxicity study of (2R,4R)-monatin salt in Crl:CD(SD) rats

(2R,4R)-Monatin salt [sodium/potassium 2R,4R-2-amino-4-carboxy-4-hydroxy-5-(3-indolyl) pentanoate] was fed at 5000, 15,000, or 35,000 ppm to Crl:CD(SD) rats over two generations. Reduced body weights were observed at all dose levels. Sustained effect on body weight gain at 35,000 ppm in the F0 and F1 parental animals was associated with lower feed efficiency, soft stool, and slightly lower numbers of implantation sites. Lower numbers of pups born and live litter size at 35,000 ppm were considered secondary to slightly lower numbers of former implantation sites in the dams. Spermatogenic endpoints, estrous cyclicity, reproductive performance, mean gestation length, and parturition were unaffected in the F0 and F1 generations. There were no effects on F1 and F2 generation postnatal survival. Reduced pre-weaning pup body weights at 35,000 ppm resulted in lower F1 and F2 body weights at study termination. Slight delays in pubertal landmarks in the F1 offspring were considered secondary to the reduced pup body weights. The no-observed-adverse-effect level (NOAEL) was 15,000 ppm for systemic, reproductive, and neonatal effects based on test article-related effects on body weight and food efficiency, slight decrease in maternal implantation sites and corresponding reduction in live litter size, and reductions in pre-weaning pup body weights at 35,000 ppm.

Regrouping of pigs by body weight at weaning does not affect growth performance, carcass quality or uniformity at slaughter of heavy weight pigs.

We studied the influence of pen uniformity at weaning (7.5 ± 0.6 kg vs. 7.5 ± 1.2 kg body weight (BW ± SD)) and sex on growth performance during the nursery (7.5 to 27.3 kg BW) and the fattening (27.1 to 130.5 kg BW) phases and carcass quality of barrows and castrated females (CF). During the nursery phase, pigs from the more uniform pens had lower feed efficiency (P = 0.05) than pigs from the less uniform pens. Also, barrows had higher average daily feed intake (ADFI) (P < 0.05) and average daily gain (P < 0.001) and better feed efficiency (P < 0.001) than CF. During the fattening phase, initial pen uniformity did not affect growth performance of the pigs but barrows tended (P = 0.08) to have higher ADFI and worse feed efficiency than CF. Trimmed primal cut yield tended to be higher for the more uniform pigs and better for barrows than for CF (P = 0.09). It is concluded that regrouping of the pigs at weaning according to uniformity of BW did not affect growth performance or carcass quality of the pigs at slaughter. Castrated females might be used as an alternative to barrows for the production of carcasses destined to the dry-cured industry.

Substituição do milho pelo farelo de algaroba (Prosopis juliflora) em dietas para juvenis de tilápia do Nilo cultivados em baixa temperatura

The objective of this study was evaluating mesquite meal as a substitute for corn in diets for Nile tilapia juveniles. Four isoproteic (34% crude protein) and isocaloric (3,150 kcal kg-1 digestible energy) diets were formulated corresponding to replacement levels (0, 33, 66 and 100%) of corn by mesquite meal. Two hundred and forty tilapia juveniles (1.55 ± 0.02 g) were housed in circular tanks (20 fish per tank of 310 L) in a completely randomized experimental design (n = 3). Fish were fed to apparent satiation three meal per day (8:30 a.m., 12:30 p.m. and 4:30 p.m.) for 70 days. Because low water temperature (23.8 ± 1.2 °C), was registered low growth and feed efficiency of fish at experiment. Tilapia juveniles weight gain, feed intake, specific growth rate and body composition were similar (P > 0.05) in all treatments. Survival increased linearly (P < 0.05) with increasing whole mesquite meal levels in diets. Mesquite meal can completely replace corn in Nile tilapia juvenile diets during periods of low water temperature.

Evaluation of Coffee Ground as a Feedstuff in Practical Diets for Olive Flounder Paralichthys olivaceus

A 10-week feeding trial was carried out to investigate the feasibility of using spent coffee ground (CG) as a potential feed ingredient for olive flounder. Growth, feed utilization, body composition and antioxidant enzyme activity were examined. A control diet was formulated and three other diets were prepared to contain 5, 10 or 15% CG (designated as Con, CG5, CG10 and CG15, respectively) by replacing for wheat flour. Two hundred forty fish (<TEX>$104{\pm}0.7g/fish$</TEX>) were allotted to 12 circular tanks of 400 L capacity at a density of 20 fish per tank and fed the experimental diets twice daily. At the end of the feeding trial, fish fed the CG5 diet exhibited significantly (P < 0.05) higher growth performance than those fed the control diet. Also, fish fed the CG10 diet had a comparable growth to that of the control group, but further increase of dietary CG inclusion level to 15% resulted in significant decrease of growth performance. Fish fed the CG15 diet showed significantly lower feed efficiency and protein efficiency ratio than other treatments. Significantly lower muscle protein content was observed in fish fed CG15 diet compared to the control. Significant reduction in plasma cholesterol concentration was found in fish fed CG15 diet compared to control. No significant changes were found in alkyle and superoxide radicals scavenging activities of plasma, muscle and liver among dietary treatments. Also, liver total protein, total antioxidant capacity, catalase and glutathione peroxidase activities were not significantly influenced by dietary inclusion of CG. According to these results, we concluded that CG can be included up to 10% in the diet for olive flounder without any adverse effects on growth, feed utilization and antioxidant enzyme activity.

Deletion of Kinin B2 Receptor Alters Muscle Metabolism and Exercise Performance.

Metabolic syndrome is a cluster of metabolic risk factors such as obesity, diabetes and cardiovascular diseases. Mitochondria is the main site of ATP production and its dysfunction leads to decreased oxidative phosphorylation, resulting in lipid accumulation and insulin resistance. Our group has demonstrated that kinins can modulate glucose and lipid metabolism as well as skeletal muscle mass. By using B2 receptor knockout mice (B2R-/-) we investigated whether kinin action affects weight gain and physical performance of the animals. Our results show that B2R-/- mice are resistant to high fat diet-induced obesity, have higher glucose tolerance as well as increased mitochondrial mass. These features are accompanied by higher energy expenditure and a lower feed efficiency associated with an increase in the proportion of type I fibers and intermediary fibers characterized by higher mitochondrial content and increased expression of genes related to oxidative metabolism. Additionally, the increased percentage of oxidative skeletal muscle fibers and mitochondrial apparatus in B2R-/- mice is coupled with a higher aerobic exercise performance. Taken together, our data give support to the involvement of kinins in skeletal muscle fiber type distribution and muscle metabolism, which ultimately protects against fat-induced obesity and improves aerobic exercise performance.

RNA-Seq Analysis of Abdominal Fat Reveals Differences between Modern Commercial Broiler Chickens with High and Low Feed Efficiencies.

For economic and environmental reasons, chickens with superior feed efficiency (FE) are preferred in the broiler chicken industry. High FE (HFE) chickens typically have reduced abdominal fat, the major adipose tissue in chickens. In addition to its function of energy storage, adipose tissue is a metabolically active organ that also possesses endocrine and immune regulatory functions. It plays a central role in maintaining energy homeostasis. Comprehensive understanding of the gene expression in the adipose tissue and the biological basis of FE are of significance to optimize selection and breeding strategies. Through gene expression profiling of abdominal fat from high and low FE (LFE) commercial broiler chickens, the present study aimed to characterize the differences of gene expression between HFE and LFE chickens. mRNA-seq analysis was carried out on the total RNA of abdominal fat from 10 HFE and 12 LFE commercial broiler chickens, and 1.48 billion of 75-base sequence reads were generated in total. On average, 11,565 genes were expressed (>5 reads/gene/sample) in the abdominal fat tissue, of which 286 genes were differentially expressed (DE) at q (False Discover Rate) < 0.05 and fold change > 1.3 between HFE and LFE chickens. Expression levels from RNA-seq were confirmed with the NanoString nCounter analysis system. Functional analysis showed that the DE genes were significantly (p < 0.01) enriched in lipid metabolism, coagulation, and immune regulation pathways. Specifically, the LFE chickens had higher expression of lipid synthesis genes and lower expression of triglyceride hydrolysis and cholesterol transport genes. In conclusion, our study reveals the overall differences of gene expression in the abdominal fat from HFE and LFE chickens, and the results suggest that the divergent expression of lipid metabolism genes represents the major differences.

Dietary protein requirement of juvenile red spotted grouper (Epinephelus akaara)

An 8-week feeding trial was conducted to assess the dietary protein requirement of juvenile red spotted grouper (Epinephelus akaara). Six semi-purified diets were formulated with varying crude protein (CP) level (ranging from 32.20% to 61.85%). Each diet was given to triplicate groups (20 fish per group, 7.88±0.04g per fish). The growth of juvenile E. akaara was significantly affected by the different dietary CP levels (P<0.05). The results of feeding trial showed that fish fed diet with 50.45% CP exhibited the highest weight gain (WG) value. Both quadratic and linear responses were observed on the feed efficiency (FE) and protein efficiency ratio (PER) as the level of dietary CP increased (P<0.05). The lowest feed efficiency (FE) was noted in diet containing 32.20% CP treatment. Moreover, daily feed intake (DFI) was highest in fish fed 32.20% CP diet. There were quadratic and linear responses in viscerosomatic indexes (VSI) and hepatosomatic index (HSI) values with dietary CP increased (P<0.05). Fish fed 32.20% CP diet obtained the highest plasma aspartate transaminase (AST) and alanine transaminase (ALT) activities. Fish fed a diet with the lowest CP obtained relatively lower energy retention (ER), lipid retention (LR) and nitrogen retention (NR). The protein content in the dorsal muscle and liver was significantly affected by the different CP levels (P<0.05). Based on the second polynomial regression analysis of WG, the dietary protein requirement for E. akaara was estimated to be 50.83%.Statement of relevanceThe main aim of this study is to quantify the optimum amount of dietary protein for juvenile red spotted grouper (E. akaara). The research outcomes will develop formulated diets for E. akaara and will have good potential for being commercialized.

Kinin B1 and B2 receptor deficiency protects against obesity induced by a high-fat diet and improves glucose tolerance in mice.

The kallikrein-kinin system is well known for its role in pain and inflammation, and has been shown recently by our group to have a role also in the regulation of energy expenditure. We have demonstrated that B1 receptor knockout (B1KO) mice are resistant to obesity induced by a high-fat diet (HFD) and that B1 receptor expression in adipocytes regulates glucose tolerance and predisposition to obesity. However, it is also known that in the absence of B1 receptor, the B2 receptor is overexpressed and can take over the function of its B1 counterpart, rendering uncertain the role of each kinin receptor in these metabolic effects. Therefore, we investigated the impact of ablation of each kinin receptor on energy metabolism using double kinin receptor knockout (B1B2KO) mice. Our data show that B1B2KO mice were resistant to HFD-induced obesity, with lower food intake and feed efficiency when compared with wild-type mice. They also had lower blood insulin and leptin levels and higher glucose tolerance after treatment with an HFD. Gene expression for tumor necrosis factor-alpha and C-reactive protein, which are important genes for insulin resistance, was reduced in white adipose tissue, skeletal muscle, and the liver in B1B2KO mice after the HFD. In summary, our data show that disruption of kinin B1 and B2 receptors has a profound impact on metabolic homeostasis in mice, by improving glucose tolerance and preventing HFD-induced obesity. These novel findings could pave the way for development of new pharmacological strategies to treat metabolic disorders such as insulin resistance and obesity.