Crude Protein Content Research Articles

Evaluation of physicochemical and flavor characteristics and primary on lipid oxidation of crucian carp under different cooking methods

This study aimed to reveal the effects of steaming, frying and boiling on the sensory and quality of the cooked crucian carp. 46, 27 and 37 volatiles were detected in the steamed fish, fried fish (FF) and boiled fish (BF), respectively, of which 7 were identified as the key volatiles. Compared with the BF and FF, the SF was richer in esters, aldehydes, alkenes and the kinds and contents of the key volatiles. The contents of moisture and crude protein were the highest in the SF. The FF exhibited the most distinctive aroma profile, much possibly associated with the highest thiobarbituric acid reactive substances (TBARS) value observed in the FF. The content of total free amino acid in the BF was the lowest while the content of umami amino acid content in the SF was the highest (p < 0.05). The nutrition of fatty acids was highest in the SF due to its highest ƩUFA/ƩSFA ratio. PLS-DA analysis showed that SF was positively correlated with the most key volatiles and several free fatty acids. These results indicated that the flavor and nutrition of SF were the highest, providing appropriate cooking methods of crucian carp for the standardized production of bean paste fish.

Hemp Seed (Cannabis sativa L.) Varieties: Lipids Profile and Antioxidant Capacity for Monogastric Nutrition.

The present research aimed to study the proximate composition, fatty acid profile, antiox-idant activity, total phenolic and N-trans-Caffeoyltyramine content of three distinct varieties of hemp seeds (Carmaenecta, Enectaliana and Enectarol, grown in a Mediterranean area (Central Italy), as feed in the diet of farm animals. Proximate composition was determined using the official methods of analyses; the fatty acid profile was determined by gas chromatography, total phenolic content (TPC) and the scavenging activity (DPPH• and ABTS•+) by the colorimetric method, and N-trans-Caffeoyltyramine content by HPLC analysis. The hemp seed Enectarol showed the highest total lipid content and the best antioxidant activity with the highest TPC, N-trans-Caffeoyltyramine content, and ABTS•+, and the lowest peroxidation index and DPPH•; Carmaenecta showed the best fatty acid profile and nutritional indices (atherogenic and thrombogenic indices and hypocholesterolemic/hypercholesterolemic ratio), and Enectaliana showed the highest crude protein and dietary fiber content. The differences observed in the chemical composition, fatty acid profile and antioxidant activity are because of the varieties, considering that all other growing conditions were the same. The results obtained suggest that hemp seed can be used as a source of lipid and protein in animal diets due to their valuable antioxidant activity and as a rich source of essential fatty acids.

Biological responses of an elite centipedegrass [Eremochloa ophiuroides (Munro) Hack.] cultivar (Ganbei) to carbon ion beam irradiation.

Carbon ion beam irradiation (CIBI) is a highly efficient mutagenesis for generating mutations that can be used to expand germplasm resources and create superior new germplasm. The study investigated the effects of different doses of CIBI (50 Gy, 100 Gy, 150 Gy, 200 Gy and 300 Gy) on seed germination and seedling survival, seedling morphological and physiological traits of an elite centipedegrass cultivar Ganbei. The results showed that irradiation greater than 50 Gy cause inhibition of seed germination, and the semi-lethal dose (LD50) is around 90 Gy for CIBI treated seeds of Ganbei. A carbon ion beam-mutagenized centipedegrass population was generated from Ganbei, with irradiation dosages from 50 Gy to 200 Gy. More than ten types of phenotypic variations and novel mutants with heritable tendencies mainly including putative mutants of stolon number, length and diameter, of internode length, of leaf length and width, of leaf chlorophyll content, of stolon growth rate, of aboveground tissue dry weight, of sward height were identified. While the total sugar content of the plants from irradiated seeds showed no obvious change in all treatments as compared to the control, the crude protein content displayed significant reduction at a high-dose treatment of 200 Gy. Genetic polymorphism was detected in mutagenized centipedegrass population using SSR-PCR analysis, suggesting that CIBI caused alteration of larger fragments of the DNA sequence. As a result, a preliminary batch of mutants was screened in this study. In summary, carbon ion beam mutagenesis is an effective way for developing centipedegrass germplasm with wider variation, and treating seeds with CIBI at a dosage of ~100 Gy could be effective in centipedegrass mutation breeding.

Co-expression of endoglucanase and cellobiohydrolase from yak rumen in lactic acid bacteria and its preliminary application in whole-plant corn silage fermentation.

Endoglucanase (EG) and cellobiohydrolase (CBH) which produced by microorganisms, have been widely used in industrial applications. In order to construct recombinant bacteria that produce high activity EG and CBH, in this study, eg (endoglucanase) and cbh (cellobiohydrolase) were cloned from the rumen microbial genome of yak and subsequently expressed independently and co-expressed within Lactococcus lactis NZ9000 (L. lactis NZ9000). The recombinant strains L. lactis NZ9000/pMG36e-usp45-cbh (L. lactis-cbh), L. lactis NZ9000/pMG36e-usp45-eg (L. lactis-eg), and L. lactis NZ9000/pMG36e-usp45-eg-usp45-cbh (L. lactis-eg-cbh) were successfully constructed and demonstrated the ability to secrete EG, CBH, and EG-CBH. The sodium carboxymethyl cellulose activity of the recombinant enzyme EG was the highest, and the regenerated amorphous cellulose (RAC) was the specific substrate of the recombinant enzyme CBH, and EG-CBH. The optimum reaction temperature of the recombinant enzyme CBH was 60°C, while the recombinant enzymes EG and EG-CBH were tolerant to higher temperatures (80°C). The optimum reaction pH of EG, CBH, and EG-CBH was 6.0. Mn2+, Fe2+, Cu2+, and Co2+ could promote the activity of CBH. Similarly, Fe2+, Ba2+, and higher concentrations of Ca2+, Cu2+, and Co2+ could promote the activity of EG-CBH. The addition of engineered strains to whole-plant corn silage improved the nutritional quality of the feed, with the lowest pH, acid detergent fiber (ADF), and neutral detergent fiber (NDF) contents observed in silage from the L. lactis-eg group (p < 0.05), and the lowest ammonia nitrogen (NH3-N), and highest lactic acid (LA) and crude protein (CP) contents in silage from the L. lactis-eg + L. lactis-cbh group (p < 0.05), while the silage quality in the L. lactis-cbh group was not satisfactory. Consequently, the recombinant strains L. lactis-cbh, L. lactis-eg, and L. lactis-eg-cbh were successfully constructed, which could successfully expressed EG, CBH, and EG-CBH. L. lactis-eg promoted silage fermentation by degrading cellulose to produce sugar, enabling the secretory expression of EG, CBH, and EG-CBH for potential industrial applications in cellulose degradation.

Comparative Analysis of the Phytochemicals, Minerals, Antioxidant and Antimicrobial Activities of Aqueous and Ethanolic Extracts of Rauvolfia vomtoria Leafs

In this study, the phytochemicals, B vitamins, minerals, antioxidants and antimicrobial activities of aqueous and ethanolic extracts of Rauvolfia vomtoria leaves were determined and compared. Qualitative and quantitative phytochemical analysis, mineral and B vitamin composition, in vitro antioxidant capacity and antimicrobial properties of both extracts were determined using standard protocols. Precise analysis of R. vomtoria revealed that the moisture content of the leaves was 8.90%, ash content was 7.70% and crude fiber content was 20.00%. The carbohydrate content of the leaves was 41%, crude protein content was 17. 00% and total fat content was 5.28%. Cardiac glycosides, tannins, phenols, saponins, phytates, steroids, terpenoids and alkaloids were detected in both aqueous and ethanolic extracts. However, significantly higher concentrations of saponins, tannins, flavonoids, steroids, alkaloids, cardiac glycosides and phytates were detected in the ethanolic extract compared to the aqueous extract. There was no significant difference in the amount of phenols and terpenoids in the two extracts (p&gt;0.05). The thiamine content in the aqueous extract was 0.20 whereas that in the ethanolic extract was 0.27. The riboflavin content was higher in the ethanolic extract (1.80) than in the aqueous extract (1.40). Similarly, the niacin content of the ethanolic extract was 0.81 whereas that of the aqueous extract was 0.81. There was no significant difference in the calcium, magnesium and phosphorus values recorded for the two extracts (p&gt;0.05). In contrast, there was a significant difference in the sodium, potassium, zinc, iron and copper contents of the two extracts with the aqueous extract containing higher amounts of potassium and zinc. The aqueous and ethanolic extracts had zones of inhibition against Enterobacter faecalis, Klebsiella pneumoniae, Salmonella typhi, Cetrobacter freundii and Shigella flexlerii. However, the zone of inhibition of the ethanolic extract against the tested organisms was higher than that of the aqueous extract. At a concentration of 10%, the aqueous and ethanolic extracts showed 87.29% and 92.03% DPPH scavenging activity, respectively. The percentage of inhibitory activity of the extracts against DPPH radical increased in a dose-dependent manner, with the ethanolic extract showing the highest DPPH radical inhibitory activity at a concentration of 50%. The results confirm that ethanol is a suitable solvent for the extraction of biologically active molecules from R.vomtoria leaves.

Effects of fasting on golden pompano Trachinotus ovatus: Physiological and biochemical responses

In practice, golden pompano (Trachinotus ovatus) reared in offshore cages may experience short-term fasting during extreme weather conditions, yet their physiological and biochemical responses remain poorly understood. To investigate the responses of this species to fasting, golden pompano weighing 138.0 ± 2.1 g were deprived of food for 0, 7, 14, 21 and 28 days, followed by assessments of body mass, somatic parameters, proximate composition, muscle glycogen, intestinal digestive enzymes, muscle amino acid and fatty acid profiles, nutritional value, and muscle texture and water holding capacity. Lower condition factor, hepatosomatic index, viscerosomatic index, hepatic glycogen, and intestinal activities of amylase, lipase and trypsin were found in the fasted fish than in the non-fasted fish, while a sharp decline in these parameters occurred on the first week of fasting. Fresh mass, dry mass, whole body and muscle contents of crude protein and lipid tended to decrease with prolonged fasting, while no statistical differences were found in these parameters between fish fasted for 7 days and the non-fasted fish. Furthermore, the decline rate of whole body crude lipid was consistently higher than that of whole body crude protein throughout the different stages of the 28-day fasting period, with the exception of the second week of fasting. No statistical differences were found in the total essential amino acids (∑EAA), non-essential amino acids (∑NEAA), ratio of ∑EAA to∑NEAA, chemical score, amino acid score, and essential amino acid index in the fasted fish compared to the non-fasted fish of group 0d. Fasting altered the muscle profile of SFA, MUFA and PUFA, sometimes reducing muscle springiness (groups 7d and 14d) and hardness (group 21d). Compared to non-fasted fish, fish fasted for 7 and 14 days exhibited statistically lower or equal drip loss, water loss rate, storage losses, and frozen exudate rate, whereas higher cooked meat rate. The above results indicate that during the 28-day fasting period, the visceral fat and hepatic glycogen are initially metabolized, followed by body proteins and lipids, to maintain the normal metabolism in fasted fish. Fasting has beneficial effects on the nutritional value of amino acids and fatty acids in muscle, although it modifies the muscle SFA, MUFA and PUFA composition and sometimes has negative effects on muscle texture. Considering the balance between body weight loss and flesh quality improvement, the duration of fasting for cultured golden pompano prior to harvesting should not exceed 14 days.

ВЛИЯНИЕ НОВОГО ОРГАНО-МИНЕРАЛЬНОГО КОМПЛЕКСА ГУМИТОН НА ПРОДУКТИВНОСТЬ И КАЧЕСТВО ЗЕРНА ОВСА

According to the data of microfield experience on soddy-podzolic neutral soil, it was shown that the treatment of oat crops with an organo-mineral complex based on Gumiton peat during the exit phase into the tube contributed to an increase in grain yield by 23% compared to the control. The content of crude protein, fiber and fat increased by 10.0; 11.6; 16.0%. The introduction of main fertilizer PhosAgro NPK (8:20:30) led to an increase in grain yield by 50.3% relative to the control. The content of crude protein, fiber and fat increased to the level of variants with use of Gumiton in the control. Processing of plots with PhosAgro NPK (8:20:30) Gumiton increased yields by 4.5% and indicators of protein, fiber, fat by 4.2; 6.5; 10.4%, respectively.

Effects of Maize–Lablab Intercropping and Lactic Acid Bacteria Additives on Forage Yield, Fermentation Quality and Profitability

Intercropping systems and exogenous microorganism additives are recognized for their potential to influence silage fermentation and quality. This study aims to evaluate the impacts of maize–lablab bean intercropping and lactic acid bacteria (LAB) additives on silage yield, nutritional quality, and economic profitability. A randomized block design was employed with two cropping patterns—maize monocrop (M) and maize–lablab intercrop (ML)—and five additive treatments: No additives (CK), and varying ratios of Lactobacillus Plantarum (LP) and Lactobacillus Buchneri (LB), T1 (100% LP), T2 (9LP:LB), T3 (8LP:2LB), and T4 (100% LB). The silage was analyzed and evaluated for its nutritional quality, fermentation quality, and fermentation effect after 90 days of fermentation. ML intercropping significantly enhanced the fresh matter yields by 8.59% and crude protein content by 8.73% compared to M. From the point of view of inoculation with different lactobacilli, the pH, AA, and NH3-N/TN were lower in the T2 and T3 treatments than in the other treatments, while LA was significantly higher. The V-score, which reflects the overall fermentation quality, was excellent across all treatments, with scores exceeding 80 points; the T2 treatment in ML silage achieved the highest score of 99.58. In addition, intercropping can increase the net income of farmers by 21.67%. In conclusion, maize–lablab intercropping combined with LAB inoculation, particularly with the T2 and T3 treatments, significantly enhances the silage quality and economic returns by reducing pH, increasing the LA content, and improving the CP levels. This study is the first to comprehensively analyze the synergistic effects of altering cropping systems and adding functional microorganisms on forage yield and fermentation quality, offering strategic insights for farms, especially mixed farms, to produce high-quality feed. We recommend adopting these methods to improve feed quality and maximize the profitability of silage production systems.

Comparative Study of Nutritional Composition, Physiological Indicators, and Genetic Diversity in Litopenaeus vannamei from Different Aquaculture Populations.

This study aimed to evaluate the quality and genetic diversity of farmed Litopenaeus vannamei across three distinct populations from Maoming City (MM), Zhanjiang City (ZJ), and Yangjiang City (YJ) in Guangdong Province. Muscle tissues from L. vannamei were analyzed for phenotypic traits, conventional nutrients, amino acids, and fatty acids, while genetic diversity was assessed using whole genome sequencing techniques. The analysis revealed that the crude protein content in shrimp across the three populations ranged from 20.87 to 21.95 g/100 g, crude fat content ranged from 0.90 to 1.50 g/100 g, essential amino acid content ranged from 5.55 to 5.86 g/100 g, total amino acid content ranged from 14.73 to 15.27 g/100 g, total fatty acid content ranged from 682.73 to 793.97 mg/100 g, total antioxidant capacity (T-AOC) ranged from 2.68 to 2.72 μmol/g, superoxide dismutase (SOD) activity ranged from 1021.97 to 1057.21 U/g, and catalase (CAT) activity ranged from 78.65 to 81.33 μmoL/min. No significant differences were observed in ash and crude fat levels among conventional nutrients, nor in the biochemical indexes T-AOC, CAT, and SOD. Genetic analysis showed that the single nucleotide polymorphism density (SNP/Kb) ranged from 15.323 to 17.461, nucleotide diversity (π) ranged from 2.98 × 10-5 to 15.84 × 10-5, polymorphism information content (PIC) ranged from 0.300 to 0.317, heterozygosity (Ho) ranged from 0.033 to 0.048, and inbreeding coefficients (FIS) ranged from 0.834 to 0.887. The genetic differentiation index (FST) values among the three populations ranged from 0.056 to 0.106. This study provides an evaluation of the germplasm resources and genetic diversity of farmed L. vannamei, offering insights for the efficient management and sustainable utilization of this species' germplasm resources.

PSXI-23 Development of sub-models to estimate protein requirements and supply of lactating dairy cows using machine learning algorithms

Abstract The objectives of this study were to develop sub-models for predicting protein requirements and supply, encompassing 1) net protein for maintenance (NPm), 2) lactation (NPl), 3) rumen undegradable protein (RUP), and 4) duodenal microbial nitrogen (MicN) from the feed protein. The dataset used in this study was constructed by integrating in vivo experimental data collected from open databases (the National Animal Nutrition Program) and articles (Journal of Dairy Science), which includes a total of 1,779 observations from 436 publications. In the development of the model, animal information and feed chemical components were used as candidate variables, and two types of machine learning algorithms, Random Forest Regression (RFR) and Support Vector Regression (SVR) were employed. After testing, the following predictors were selected for predicting: 1) NPm: body weight (BW) and dry matter intake (DMI), 2) NPl: BW, DMI, days in milk (DIM), and dietary organic matter (OM) and crude protein (CP) contents, 3) RUP: DIM, DMI, dietary DM content, and CP fraction intake (B and C), and 4) MicN: DIM, DMI, DM, dietary neutral detergent fiber (NDF) content, CP fraction intake (A, B, and C). The selected models were assessed using a cross-validation method with the following statistical metrics including the coefficient of determination (R2), root-mean-square error of prediction (RMSEP), residual analyses, and concordance correlation coefficient (CCC). For the RUP and MicN models, they were compared with the NASEM (2021) model. In predicting NPm, both SVR and RFR algorithms demonstrated increased precision (R2 = 0.965 vs. 0.969) and accuracy (RMSEP = 9.7 vs. 9.2 g/d); however, during residual analysis, the RFR model showed a statistically significant slope bias (P &amp;lt; 0.05). In the NPl prediction, the RFR algorithm showed slightly greater performance compared with SVR (R2 = 0.864 vs. 0.814 and RMSEP = 86.7 vs. 98.5 g/d). However, similar to the NPm prediction, the RFR model displayed a statistically significant slope bias (P &amp;lt; 0.05). In the supply model, the RFR model exhibited the greatest precision and accuracy in predicting RUP (R2 = 0.60, RMSEP = 0.326 kg/d, and CCC = 0.71) without any biases. This model achieved a 2.37-fold increase in R2 and a decrease of 0.111 kg/d in RMSEP compared with the NASEM model. As for MicN prediction, the SVR model performed the best (R2 = 0.76, RMSEP = 42.4 g/d, and CCC = 0.86) without biases. This model attained a 19-times improvement in R2 and a reduction of 38.7 g/d in RMSEP when compared with the NASEM model. In conclusion, the models developed using machine learning algorithms can be helpful for accurately and precisely predicting protein requirements and supply based on animal information and the chemical composition of feed.

PSI-26 Effects of particle size and enzyme supplementation on the energy value of field peas fed to growing pigs

Abstract An experiment was conducted to determine if particle size and enzyme supplementation affects the digestible energy (DE), metabolizable energy (ME), and net energy (NE) contents in field peas fed to growing pigs. Male weaned pigs [n = 30; TN70 × TN Tempo; body weight (BW) = 16.5 ± 0.4 kg] were assigned to 1 of 5 dietary treatments: 4 consisting of 50% peas and a corn-soybean meal basal diet. The experiment was carried out as a completely randomized design with treatments arranged in a 2 × 2 factorial design, based on two particle sizes (500μm, 700μm) and two levels of carbohydrase supplementation (0 g/mt, 1,000 g/mt) to give 6 replicates per treatment. Diets were formulated to meet or exceed NRC (2012) requirements. The study was carried out in 3 consecutive periods, each consisting of 15 d; the first 10 d were for adaptation, followed by 5 d of total fecal and urine collection (marker to marker procedure) to calculate DE and ME of diets. The energy content of peas was determined using the difference method. Data were analyzed using the MIXED procedure of SAS. The model included the particle size, enzyme supplementation, and their interaction as a fixed effect. The period was included as a random effect. Least squares means for each treatment were adjusted using Tukey post-hoc test. Dry matter (DM), acid detergent fiber, neutral detergent fiber, gross energy, starch, ash, crude protein, and ether extract contents were analyzed to allow for the prediction of NE content of peas. There were no interactions between particle size and enzyme supplementation on dietary energy values. Also, no main effects of particle size and enzyme supplementation were observed. The average DE, ME, and predicted NE contents for peas were determined to be 3,848, 3,735, and 2,691 kcal/kg DM, respectively. In conclusion, enzyme supplementation and particle size did not influence the DE, ME, and NE contents of the peas.

PSIX-19 Effect of protein and starch level on N balance and ruminal fermentation parameters in steers consuming low-quality forage: Bos taurus taurus

Abstract Globally cattle convert low-quality forage to beef and milk; therefore, understanding protein utilization in Bos taurus taurus is critical to enhancing sustainability as over and under-supplementation of protein are economically and environmentally costly. Low-quality forage lacks the N necessary for proper utilization and metabolic function. Supplemental protein improves low-quality forage utilization and is expected to increase N absorption and retention. Supplement starch can increase volatile fatty acid (VFA) production and energy supplied to the animal; however, too much starch decreases ruminally available N and pH potentially decreasing fibrolytic activity. Accordingly, our objective was to determine the effect starch supplementation on N balance and ruminal fermentation parameters in Bos taurus steers. Ruminally cannulated Angus steers [n = 5; body weight (BW) = 375 ± 45 kg] were used in a 4 × 4 Latin square to evaluate the effect of decreasing supplemental starch when consuming King Ranch Bluestem hay (3.5% CP, 73% NDF). Steers received four isonitrogenous (130 mg N/kg BW) supplements providing increasing levels of starch (2% starch = 100% soybean meal; 20% starch = 26.3% corn, 73% soybean meal, 0.7% urea; 38% starch = 51.6% corn, 47% soybean meal, 1.4% urea; 56% starch = 78.6% corn, 19% soybean meal, 2.4% urea). Five 14-d periods were conducted, consisting of 9 d adaptation and 4 d to measure intake and digestion, and 1 d for ruminal fermentation. Supplemental N intake decreased linearly (P &amp;lt; 0.01) with increasing starch as the crude protein content of the soybean was underestimated. Forage and total N intake were not affected by starch level (P ≥ 0.17). Fecal and total urinary N excretion were not different between starch levels (P ≥ 0.43). Urinary ammonia-N and urea-N averaged 6.6 and 16.8% of total urinary N excretion, respectively, but no differences between starch levels were observed (P ≥ 0.39). Level of starch supplementation had no effect on N retention and absorption (P ≥ 0.50). There was a treatment × time interaction observed for ruminal ammonia concentration (P &amp;lt; 0.01). All treatments, except 2% starch, peaked at 4 h post feeding, 20 and 38% treatments gradually decreased following four, but the concentration of ruminal ammonia decreased by 80% between 4 h and 8 h after feeding in the 56% starch treatment. Starch level had no effect total VFA concentration, VFA molar proportions, or ruminal pH (P ≥ 0.10). In conclusion, providing supplemental starch did not affect N balance or VFA production when fed to steers consuming low-quality forage. Nitrogen balance and VFA production likely were not affected because all supplements provided sufficient ruminally available N and, therefore, exerted minimal effects on forage utilization.

469 Reducing crude protein levels with amino acid supplementation in the finishing diets of heavy Duroc sire line pigs: Effects on carcass and meat traits in males and females

Abstract Nutrition represents 70% of pig production costs, particularly protein; therefore, decreasing protein costs is of capital importance. Reducing crude protein (CP) contents to levels below recommended whilst supplementing with amino acids (AAs) is an interesting strategy to reduce costs without decreasing production performances. It has been conducted essentially in lean genotypes during the growth stage. Few studies address heavy genotypes or sex differences during the finishing period. Our objective is to study carcass and meat (loin) traits of heavy [Duroc X (Landrace X Large-White)] male and female pigs during the finishing stage under a 2% CP reduction with crystalline AA supplementation, hypothesizing that both sexes will be affected equally. In total, 60 males and 60 females, 9 wk old animals were used and allotted in split-sex pens (6 pigs/pen) with water and dry feed ad libitum. At 15 wk of age, when pigs weighed an average of 68 kg, two isoenergetic diets with different CP levels were provided (145 and 125 g CP/kg, control and low-CP) during the last 42 d of fattening. In the low-CP diet, crystalline AAs were added. On last day of the trial, animals weighed 116.5 kg on average and were slaughtered. Hot carcass weights and yields, ham fat thickness, lean meat percentage and boar taint by human nose scoring were determined. Loin samples (one per pen) were used to determine thawing losses, pH, color, Texture Profile Analysis (TPA: hardness, cohesiveness, springiness) and chemical composition (moisture, ash, protein, collagen, fat, and saturated fat). Data were analyzed using the simple least squares models that included dietary treatment and sex and their interaction as fixed effects with the pen as the experimental unit. Carcass weights were greater in control males than in females (91.2 vs 85.7 kg; P &amp;lt; 0.05). No effect of sex or diet was detected on carcass yields, lean contents or ham subcutaneous fat thickness. There was a great impact of sex for loin subcutaneous fat thickness, with males having 7 to 8% greater values in both dietary treatments (P = 0.011). Low-CP females had a greater percentage of carcasses of greater lean content compared with the three other groups (P &amp;lt; 0.05). Boar taint, carcass pH, color traits, chemical analysis and TPA did not differ across diets. A strong dietary influence was noticeable with animals of both sexes in the Low-CP diets having greater fat and saturated fat contents than animals in the control groups (P = 0.02). In conclusion, the 20g/kg CP reduction supplemented with AAs can efficiently be used in heavy Duroc sire line genotype during the finishing phase without leading to major impairments in carcass or meat traits, regardless of sex.

470 Reducing crude protein levels with amino acid supplementation in the finishing diets of heavy Duroc sire line pigs: Effects on growth performance and nitrogen balance in males and females

Abstract Nutrition represents 70% of pig production costs, particularly protein; then, decreasing protein costs is of capital importance. Reducing crude protein (CP) contents to levels below recommended whilst supplementing with amino acids (AAs) is an interesting strategy to reduce costs without decreasing production performances with environmental benefits. It has been conducted essentially in lean genotypes during the growth stage. Few studies address heavy genotypes or differences between males and females during the finishing period. Our objective is to study productive performances of heavy [Duroc X (Landrace X Large-White)] male and female pigs during the finishing stage under a 2% CP reduction with crystalline AA supplementation, hypothesizing that both sexes will equally be affected. In total, 60 males and 60 females were used. At 9 wk of age, animals were allotted in split-sex pens (6 pigs/pen, 0.9 m2/animal) with water and dry feed ad libitum. At 15 wk of age, when pigs weighed an average of 68 kg, two isoenergetic diets with different CP levels were provided (145 and 125 g CP/kg, control and low-CP) during the last 42 d of fattening, under the ideal protein concept. In the low-CP diet, crystalline AAs were added. Feed intake was measured daily, and animals were weighed every 3 wk to calculate average daily feed intake (ADFI), average daily gain (ADG), feed conversion ratio (FCR) and N balance on d 21 and 42. Data were analyzed using the simple least squares models that included dietary treatment and sex and their interaction as fixed effects with the pen as the experimental unit. At d 21, animals weighed 90 to 95 kg with males being 5 to 6 % heavier (P &amp;lt; 0.01). No significant differences were recorded regarding diet. The same difference (P &amp;lt; 0.001) was recorded at day 42, with males (119-122 kg) being 7.25% heavier than females in both treatments. Males had 16% higher ADGs than females in both treatments (P &amp;lt; 0.0001) No differences were recorded for ADFI as a consequence of sex for both diets. FCRs were higher in females of both nutritional treatments (P &amp;lt; 0.0001). Retained N was 22% greater in males than in females for both dietary treatments. The N efficiency was greater in Low CP males by comparison with low CP females and control males, whereas control CP females had decreased N efficiency compared with all other experimental groups. Results demonstrate that the 20g/kg CP reduction supplemented with AAs can efficiently be used in heavy Duroc sire line genotypes during the finishing phase without a decrease in production parameters with females having poorer growth performances than males, whereas N efficiency was impaired when females had no limiting dietary CP.

224 Yield and nutritive values of a polycrop and annual cereal monoculture used in winter swath grazing

Abstract This 3-yr study evaluated a comparative biomass yield and nutritive values of 2 forage systems: 1) a cereal monoculture (CDC-SO1 oats) and 2) a polycrops (PC) consisting of oat, brassicas (turnip and rape) and forage pea (4010) harvested at the hard dough (HD) stage for winter swath grazing purpose. A 12-ha field was divided into six, 2-ha paddocks, where each paddock was randomly assigned to 1 of 2 replicated (n = 3) forage systems. Forages were seeded in June and sampled for biomass yield and nutritive value at the soft dough (SD) and HD stages of oats. The seeding rate of oat monoculture (OM) was 157 kg/ha, while the PC was 45 kg/ha (oat), 11 kg/ha (forage pea) and 6 kg/ha (brassica). Forage samples were collected from a 0.6 m2 area at 24 pre-selected GPS points (4 per paddock), weighed and then oven-dried to a constant weight to determine DM yield. Data were analyzed using the PROC MIXED procedure of SAS and included treatment effects and treatments × stage interactions. Year was treated as a random effect due to climatic variations across years. For OM, there was a significant difference (P = 0.03) in biomass yield between SD (7,762.7 ± 1,217.9 kg/ha) and HD (8,902.8 ± 1,217.9 kg/ha) stages, while PC biomass yield did not differ (P = 0.94) between SD (5,922.4 ± 1,217.9 kg/ha) and HD (6,163.1±1,217.9 kg/ha) stages. The biomass yields between the two forage systems were different (P &amp;lt; 0.05) at the SD and HD stages. Crude protein (CP) concentration did not differ (P &amp;gt; 0.05) between the OM and PC at SD (10.4 vs 10.3%) and HD (8.9 vs 9.6%) stages. At the SD stage, significant differences (P &amp;lt; 0.05) between OM and the PC were observed for neutral detergent fiber (NDF, 50.9 vs 44.1%), calcium (0.2 vs 0.5%), phosphorus (0.2 vs 0.3%), and RFV-relative feed value (120.3 vs 142.2). Similarly, the starch (20.9 vs 16.5%), calcium (0.2 vs 0.5%), and phosphorus (0.2 vs 0.3%) values for OM and PC, respectively, also differed (P &amp;lt; 0.05) at the HD stage. Differences (P &amp;lt; 0.05) were observed between the SD and HD stages of OM for acid detergent fiber (ADF, 30.1 vs 27.0%), total digestible nutrient (TDN, 65.4 vs 67.9%), and starch (14.9 vs 20.9%) content, respectively. Study results suggest that swathing OM at the HD stage would be beneficial in terms of greater biomass yield without compromising quality, while PC can be harvested at either SD or HD stages based on the annual cereal component. Also, the lack of significant difference in the RFV, CP and TDN values between the PC and OM at the HD stage suggests that PC could be a viable alternative forage system for winter swath grazing.

394 Cover crops for efficient grazing systems

Abstract Grazing of cool-season cover crops provides a sustainable solution for extending the grazing season while potentially reducing the environmental impact of conventional row-crop farming practices. The primary objective of this study was to evaluate how different mixtures of cover crops affect stocker performance when grazed. The study was conducted across 18 paddocks that were sown with grass [‘Coker’ oat (Avena sativa)], grass + legume [‘Dixie’ crimson clover (Trifolium incarnatum)], or grass + legume + brassica [‘Turnip’ brassica (Brassica rapa subsp.; rapa)] at the Wiregrass Research and Extension Center in Headland, AL. These paddocks were randomly assigned to either grazed or un-grazed conditions (n = 3). In this study, yearling beef steers with an average body weight (BW) of 266 ± 44 kg were grazed in paddocks using the put and take method to maintain a forage allowance of 1 kg dry matter per kilogram of BW. Forage samples were collected biweekly to analyze biomass, botanical composition, and forage nutritive value. Grazing occurred from January 17 to March 22, 2023 (65 d). Steer BW were recorded at the beginning and end of the grazing season to calculate average daily gain. The data were subjected to analysis as a two-way ANOVA using Glimmix in SAS 9.4 (SAS Institute, Cary, NC), harvest date was considered a repeated measure. No treatment × grazing interaction was observed on forage yield performance [average (AVG) forage yield kg DM/ha; P = 0.460]. In addition, no difference was observed among the different cover crop mixtures (AVG forage yield kg DM/ha; P = 0.670). Grazed paddocks had a greater crude protein when compared with ungrazed paddocks (Grazed vs. Ungrazed %; P = 0. 017). However, there was no effect of cover crop mixture on crude protein (CP) concentration (AVG CP %; P = 0.670 for treatment effect). These results indicate that cool-season annual cover crops can provide sufficient forage yield and quality to support sufficient animal gains, even during the relatively short grazing season. Incorporating cover crops not only improves agricultural sustainability but can also enhance the resilience and long-term health of the agroecosystem.

245 The influence of deferment and season of use on beef cattle diet quality and composition following a rangeland wildfire

Abstract Research has shown that forage quality increases after a fire. Greater crude protein content in forage can be beneficial for livestock, and even attract herbivores to recently burned areas. However, there has been little research into how forage quality changes within the first 2 yr after a fire and how it affects livestock diet quality or composition. Therefore, this project was conducted within a burn area of an August 2020 wildfire to evaluate the effect of seasonal deferment and annual rest on diet quality, botanical composition, and foraging efficiency of beef cattle grazing burned rangeland. A randomized complete block design was used comparing June grazing versus September grazing with cow/calf pairs, and no deferment versus a 1 yr deferment of grazing. Sixteen 4-hectare pastures were used, with eight being grazed in 2021 and 2022, and eight only grazed in 2022. Pastures were grazed in either June or September by cow-calf pairs for 2 d at a time. In June, 20 cow/calf pairs were used, and 16 pairs were used in September to account for calf growth/intake. Cattle diet composition and masticate samples were collected during 20-min bite-count periods using six ruminally cannulated cows in each pasture prior to and after 2 d grazing periods. Composition of diets upon pasture entry differed among treatments (P &amp;lt; 0.01) with June diets in greater proportions of forbs than September diets. In addition, June diets with no deferment had greater forb composition than June diets with 1 yr deferment (P &amp;lt; 0.01). Crude protein in June diets were substantially greater than September diets (P &amp;lt; 0.01) and within the June grazing period, greatest for the non-deferred treatment (P &amp;lt; 0.01). June diets had decreased neutral detergent fiber (NDF) concentrations than September diets (P &amp;lt; 0.01) and within the June grazing treatments, the first year after burning was least in NDF content (P &amp;lt; 0.01). There was no difference in ash concentration for all treatments and years (P ≥ 0.07) averaging 16.46% ash content. There was no effect of grazing treatment on grams per bite (P ≥ 0.34) averaging 1.36 grams per bite for pre- and post-grazing treatments. In summary, season of use and timing of grazing following a wildfire has an impact on cattle diet composition and quality with the greatest impact in the spring following a wildfire.

91 Awardee Talk: Using respiration calorimetry to estimate energy balance to estimate energy balance and methane emissions

Abstract Understanding relationships between chemical components of the diet and methane production will allow nutritionists to develop formulation strategies to decrease methane emissions. Diets that produce acetate liberate hydrogen that can be used by methanogenic archaea to produce methane. Propionate is a hydrogen sink and diets that lead to increased propionate production decrease acetate and methane production. The objective was to evaluate relationships between methane emissions and dietary chemical components and feed intake using published databases and make diet formulation recommendations that could be used to decrease methane production in finishing beef cattle. A total of 263 treatment mean observations from respiration calorimetry studies with beef cattle and dairy steers and heifers were used to evaluate relationships between methane emissions, dietary chemical components, and feed intake. Among the chemical components evaluated, dietary neutral detergent fiber and starch were strongly related to methane yield. The relationship between dietary ether extract and methane yield was variable and there was no relationship between dietary crude protein concentration and methane yield. Additionally, the ratio of metabolizable energy relative to gross energy intake had a strong relationship to methane yield. Formulation strategies to increase dietary starch and decrease dietary neutral detergent fiber should allow the feedlot industry to decrease enteric methane production.

Exploring agricultural waste substrate for enhancement of &lt;i&gt;Pleurotus ostreatus&lt;/i&gt; cultivation

The proximate composition of the organic waste substrates used in cultivating Pleurotus ostreatus was analyzed, and the results revealed significant variations in various nutritional components among the substrates. Palm Chaff had the highest ash content (7.14%), followed by Oil Palm Empty Bunch (5.08%), Yam Peel (4.29%), and Saw Dust (1.36%). This indicated that Palm Chaff was the richest in minerals, while sawdust had the lowest mineral content. In addition, Yam Peel had the highest moisture content (8.46%), followed by Palm Chaff (5.87%), Oil Palm Empty Bunch (4.62%), and Saw Dust (2.83%). This suggested that Saw Dust was the driest substrate. Furthermore, Oil Palm Empty Bunch had the highest crude lipid content (1.94%), followed by Palm Chaff (1.38%), Yam Peel (1.13%), and Saw Dust (0.04%). Moreover, Oil Palm Empty Bunch had the highest crude protein content (2.56%), followed by Yam Peel (2.1%) and Palm Chaff (2.02%). Saw Dust had the lowest crude protein content (1.74%). Besides, Oil Palm Empty Bunch had the highest crude fiber content (48.27%), followed by Palm Chaff (36.94%), Saw Dust (26.17%), and Yam Peel (14.36%). In addition, Saw Dust had the highest carbohydrate content (67.86%), followed by Yam Peel (69.64%) and Palm Chaff (46.65%). Oil Palm Empty Bunch had the lowest carbohydrate content (37.58%). These findings offered valuable insights into the suitability of each substrate for cultivating Pleurotus ostreatus Additionally, it enabled growers to make informed decisions about substrate selection based on the specific nutritional needs and growth requirements of the mushrooms. The impact of various organic waste substrates on the growth dynamics of Pleurotus ostreatus (oyster mushroom), revealed significant variations in several key parameters. In primordial Formation, the number of early-stage fruiting bodies formed varied between 12 and 36 across different substrate formulations. The highest primordial formation was observed in treatment A + B + C + D (36), while treatments involving individual substrates or their combinations had the lowest primordial formation (12). Furthermore, in Fruiting Body Production, the number of mature mushrooms produced varied across treatments. Treatment A + C resulted in the highest number of fruiting bodies (26), while treatments involving combinations of substrates (B + C + D, A + B + C, A + B + C + D, C + D) had the lowest number of fruiting bodies (3). Overall, the findings highlight the influence of specific substrate combinations on various aspects of mushroom growth dynamics. However, the choice of growth substrates did not significantly impact the overall weight and biological efficiency of Pleurotus ostreatus in this study. These results provide valuable insights for optimizing mushroom cultivation practices.

Hybrid meat products: the physicochemical and microstructural properties of beef meat emulsion produced with jackfruit (Artocarpus heterophyllus) flesh and bamboo (Bambusa polymorpha) shoot as meat substitutes

SummaryHybrid meat products are a beneficial approach to incorporating plant proteins into conventional meat formulations, taking into account current market trends that emphasise the partial decrease in animal protein content. This study aimed to evaluate the effects of using different percentages of beef meat (BM), jackfruit flesh (JF) and bamboo shoot (BS) as a meat substitute in beef meat emulsion. Emulsion with 100% BM (Control), (A) 50% JF + 50% BM, (B) 50% BS + 50% BM, (C) 50% BM + 25% JF + 25% BS, (D) 100% JF and (E) 100% BS were developed. Six formulations of meat emulsion samples were prepared and analysed in terms of physicochemical and microstructure properties. The substitution of JF and BS in meat emulsion resulted in more stable emulsion stability. The WHC and pH values showed no significant differences (P &gt; 0.05) between samples. The samples with different percentages of JF and BS had significantly increased (P &lt; 0.05) the moisture content and the crude fibre content, however, it significantly reduced (P &lt; 0.05) the crude protein content. No significant difference (P &gt; 0.05) in ash and fat content for the formulated meat emulsions from the control. One hundred per cent BS showed higher lightness (L*), yellowness (b*) and lower redness (a*) values significantly (P &lt; 0.05) compared to the control. One hundred per cent JF and 100% BS depicted significant differences (P &lt; 0.05) for the textural properties and gel strength compared to the control. The scanning electron microscopy (SEM) provided evidence for the microstructure that the higher the percentages of plant‐based ingredients, the smaller the cavities. Overall, the incorporation of 50% BM + 25% JF + 25% BS could produce the best‐suited meat substitution product.