Carcass Characteristics Research Articles

Effects of Cattle Breeds and Dietary Energy Density on Intake, Growth, Carcass, and Meat Quality under Thai Feedlot Management System

This study determines the effects of varying dietary metabolizable energy densities on Holstein Friesian and Charolais crossbred beef cattle in fattening phases. The research focuses on nutrient utilization, ruminal fermentation, growth performance, carcass traits, and meat quality. Thirty-six steers were used in the feeding trial that lasted for six months according to a 2 × 3 factorial arrangement in a randomized complete block design (Factor A, cattle breeds (Holstein Frisian, Charolais crossbred); B, metabolizable energy density (10.5, 11.1 and 11.8 MJ/kg DM)) with six replications. The dietary energy density had no interaction with the cattle breeds (p > 0.05). Despite fewer carcass yields, Holstein Friesian crossbreds indicate superior eating quality to Charolais crossbreds on drip loss, meat iron content, and Warner–Bratzler shear force due to increased intramuscular fat content (p < 0.05) with similar meat color (p > 0.05). Increased dietary energy density positively impacts nutrient and energy intake and rumen fermentation (p < 0.05) but did not affect growth and carcass traits (p > 0.05). This research suggests the potential of Holstein Friesian crossbreds for intensive beef production, providing valuable insights into optimal feeding strategies for achieving quality meat outcomes. On-farm feeding trials are needed to develop a practical and economical Thai beef feedlot management system

Trace mineral source and chromium propionate supplementation affect performance and carcass characteristics in feedlot steers.

Angus-crossbred steers (n = 400; 369.7 ± 7.6kg) were used to determine the influence of trace mineral (TM) source and chromium propionate (Cr Prop) supplementation on performance, carcass characteristics, and ruminal and plasma variables in finishing steers. Steers were blocked by body weight (BW) and randomly assigned within block to treatments in a 2 x 2 factorial arrangement, with factors being: 1) TM source (STM or HTM) and 2) Cr supplementation (0 or 0.25mg Cr/kg DM, -Cr or +Cr, respectively). Treatments consisted of the addition of: 1) sulfate TM (STM; 90, 40, and 18mg/kg DM of Zn, Mn, and Cu, respectively), 2) STM and 0.25mg Cr/kg DM from Cr Prop, 3) hydroxychloride TM (HTM; 90, 40, and 18mg/kg DM of Zn, Mn, and Cu, respectively), and 4) HTM and 0.25mg Cr/kg DM from Cr Prop. Each treatment consisted of 10 replicate pens with 10 steers per pen. Body weights were obtained on consecutive days at the initiation and termination of the 154-d study. Steers were fed a steam-flaked corn-based finishing diet. Ractopamine hydrochloride was fed for the last 31 d of the study. Ruminal fluid and blood samples were obtained from one steer per pen on d 28 and 84 for ruminal volatile fatty acids (VFA) and plasma TM and glucose analysis. Steers were slaughtered at the end of the study and individual carcass data were collected. No Cr x TM source interactions were detected. Steers supplemented with HTM had greater (P ˂ 0.04) hot carcass weight (HCW), dressing percentage (DP), longissimus muscle (LM) area, and USDA yield grade (YG), and tended (P ˂ 0.12) to have greater average daily gain (ADG) than those receiving STM. Average daily gain, gain:feed, dressing percentage, and longissimus muscle area were greater (P ˂ 0.04) for +Cr steers compared to - Cr steers. Hot carcass weight tended (P ˂ 0.06) to be greater for +Cr steers. Ruminal acetate concentrations at 28 d were lesser (P ˂ 0.01) for HTM vs. STM steers, and greater (P ˂ 0.04) for +Cr steers compared to - Cr steers. Plasma concentrations of Zn, Cu, and Mn were not affected by TM source or Cr supplementation. Steers supplemented with Cr had greater (P ˂ 0.05) plasma glucose concentrations than - Cr steers at 28 but not at 84 d. Results of this study indicate replacing STM with HTM improved carcass characteristics in finishing steers, and Cr Prop supplementation improved steer performance and carcass characteristics.

Synergic Effects of Carica papaya Leaves and Fermented Fish Waste on Growth Performance, Carcass Yields, Sensory Attributes, and Profitability in Broiler Production

Poultry production sustainability requires innovative dietary supplements to improve performance while addressing environmental concerns. This research investigates the effects of supplementing broiler chicken diets with Carica papaya leaf meal (CPL) and fermented fish waste (FFW) in water on various growth parameters, carcass traits, sensory attributes, and profitability. A Randomized Complete Block Design (RCBD) with a 2x4 factorial arrangement was employed, evaluating two factors: CPL dietary supplementation at 10% and FFW water supplementation at 0%, 5%, 10%, and 15%. Each treatment combination was replicated four times with five broiler chicks per replication, totaling 160-day-old broilers. Results indicated that while CPL negatively influenced final body weight and weight gain, FFW positively impacted feed intake, final weight, and weight gain. Additionally, FFW supplementation led to significant increases in drumstick and thigh weights compared to the control, with notable interactions observed between CPL and FFW for breast, wing, and back weights. However, neither CPL nor FFW affected the weights of edible visceral organs. Sensory evaluation revealed no significant differences in meat quality attributes across treatments. Despite increased production costs, supplementation with CPL and FFW resulted in higher dressed weights and profitability, with the highest return on investment achieved by broilers receiving the standard diet plus 15% FFW supplementation. These findings suggest that optimized utilization of CPL and FFW at 10% and 15% respectively, presents an economically viable strategy for enhancing broiler growth, carcass quality, and profitability while leveraging nutritional benefits and reducing environmental waste.

Production and use of dry-rolled hybrid rye grain as a replacement for barley grain on growth performance and carcass quality of feedlot steers

Abstract The objectives were to compare cereal grain and straw yield between barley and hybrid rye (HR), and to evaluate whether the inclusion of dry-rolled HR grain as a replacement for barley grain affected feed intake and growth for growing cattle, and feed intake, growth, and carcass characteristics for finishing cattle. Crop yield was measured by directly weighing harvested grain and straw bales (n=3 plots/grain type). Three-hundred sixty steers with an initial body weight (BW) of 348 ± 40 kg were stratified by BW and randomly assigned to 1 of 24 pens during the growing phase (n=8; 65 d). The control diet (BCON) included 60.22% barley grain with HR included by replacing 50 (BMID) or 100% (BHIGH) of the barley grain on a dry matter (DM) basis. Steers were re-randomized for the finishing phase (n=6; 118 d) and treatments included a control diet containing 88.60% barley grain (FCON) with HR replacing 33 (FLOW), 67 (FMED), or 100% (FHIGH) of the barley grain (DM basis). The grain yield was greater (P = 0.04) and straw yield tended (P = 0.06) to be less for HR than barley. There were no effects of HR inclusion on DM intake (DMI) or G:F during the growing phase, but ADG responded quadratically (P = 0.02) with cattle fed 50% HR having the greatest gain. During finishing, DMI decreased linearly as HR grain inclusion increased (P < 0.01). Average daily gain initially increased from FCON to FLOW followed by a decrease with increasing HR inclusion (quadratic, P < 0.01), but G:F was not affected. Hot carcass weight was greatest for FCON with the magnitude of difference between FCON and the HR treatments increasing with increasing inclusion of HR (quadratic, P = 0.02). There was a linear increase in dressing percentage (P = 0.02) and a linear reduction in back fat thickness (P = 0.04) with increasing inclusion of HR. Increasing the inclusion of HR during finishing cubically (P < 0.01) affected the proportion of minor and severe liver abscesses with an average of 34.60% severely abscessed livers when HR was included compared to 11.11% for BCON. Hybrid rye may have greater grain yield than barley, and partial replacement of barley grain with HR may improve ADG without affecting DMI or G:F during the growing phase. However, replacing barley grain in finishing diets with HR decreases DMI, increases risk minor and severe liver abscesses, but does not affect feed conversion, suggesting HR should not replace more than 33% of the barley grain to maintain ADG.

Algae as an alternative source of protein in poultry diets for sustainable production and disease resistance: present status and future considerations

Integrating algae into poultry diets offers a promising avenue for enhancing nutrition, boosting sustainability efforts, and potentially stimulating disease resistance. This comprehensive review delves into the essence, diversity, chemical composition, and nutritional merits of algae, spotlighting their emergence as innovative nutrient sources and health supplements for poultry. The growing interest in algae within poultry nutrition stems from their diverse nutritional profile, boasting a rich array of proteins, lipids, amino acids, vitamins, minerals, and antioxidants, thus positioning them as valuable feed constituents. A key highlight of incorporating both macroalgae and microalgae lies in their elevated protein content, with microalgae varieties like Spirulina and Chlorella exhibiting protein levels of up to 50–70%, outperforming traditional sources like soybean meal. This premium protein source not only furnishes vital amino acids crucial for muscular development and overall health in poultry but also serves as an exceptional reservoir of omega-3 fatty acids, notably eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), presenting multiple health benefits for both poultry and consumers alike. Moreover, algae boast antioxidant properties attributed to bioactive compounds like phycocyanin and astaxanthin, mitigating oxidative stress and boosting the bird’s immune response, thereby fostering robust health and disease resilience. Incorporating macroalgae and microalgae into poultry diets yields positive impacts on performance metrics. Research evidence underscores the enhancement of growth rates, feed conversion ratios, carcass quality, and meat attributes in broilers, while in layers, supplementation promotes increased egg production, superior egg quality, and increased concentrations of beneficial nutrients such as omega-3 fatty acids. Furthermore, algae hold promise for mitigating the environmental footprint of poultry production, though significant outcomes from trials remain sporadic, necessitating further research to elucidate optimal dosages and blends for different algae species in poultry diets. Standardizing the composition of algae utilized in research is imperative, paving the way for potential applications in poultry nutrition as growth stimulants and substitutes for antibiotics. Nonetheless, a deeper understanding of dosage, combination, and mechanism of action through rigorous scientific investigation is key to unlocking algae’s full potential within poultry nutrition.

Accounting for dominance genetic variation in carcass quality traits of Canadian crossbred beef cattle

The objectives of this study were to evaluate the contribution of additive and dominance genetic effects to the phenotypic variation of carcass quality traits and to identify the underlying genetic variants associated with these traits. A total of 3,958 Canadian crossbred beef cattle with phenotype and genotype data were used in two models: 1) additive and 2) joint additive and dominance genomic model which included fixed contemporary group, and covariates of slaughter age, and the eigenvectors of five principal components to account for population structure. Variance components and genome-wide association analyses were performed, and a 10% genome-wide false discovery rate (FDR) was applied to declare associations as significant. Genomic heritability ranged from 0.31±0.03 for ultrasound rib eye area to 0.46±0.05 for marbling score. Up to 10% dominance genetic variation was observed for ultrasound rib eye area and marbling score, indicating the contribution of dominance genetic effects to these trait variations. Eleven overlapping significant SNP associations were identified across the studied traits and models. The identified candidate genes (e.g. BTC, SPP1, and SEPSECS) have biological functions related to tissue growth and skeletal muscle development and can be further validated in other cattle populations to determine their usefulness for beef cattle genetic improvement.

Effects of in ovo injection of organic selenium on the hatchability of broiler breeder hen eggs and resulting chick physiology and performance.

Selenium is an essential mineral for poultry. The conflicting reports about its in ovo injection are the justification for the more detailed investigation. The aim of this study was to investigate the effects of in ovo injection of organic selenium on the hatching traits of broiler chickens and their performance. Three hundred and twenty eggs of Ross 308 strain with an average weight of 65g and 160 chicks were randomly divided into 4 treatment groups (each with 8 replicates of 10 eggs each for hatching parameters and 4 replicates of 10 chicks for broiler farming parameters): negative control (no injection), positive control (in ovo injection of 0.272mL of normal saline solution) and 2 selenium treatments (in ovo injection of 2.72 or 5.44μg of organic selenium). Injection was into the amniotic sac on the 10th day of incubation. Effects of in ovo injection on hatching and performance traits, blood parameters, immune responses, carcass characteristics, meat fatty acid profile, cecal microbial population and selenium consternation in the tibia were measured. Fewer chicks from the injected treatments hatched than from the negative control group (p<0.01). However, the injection of selenium increased feed intake and the final weight of the birds (p<0.01). Blood parameters were also affected. Glucose and cholesterol in experimental treatment chicks was lower than those of the controls (p<0.01), whereas blood lipoproteins (VLDL, LDL and HDL) and the ratio of cholesterol to HDL was significantly increased in the treatments injected with selenium (p<0.01). There was no significant difference in the immune response or microbial population between the experimental groups, but carcass components, such as thigh, breast, wing and abdominal fat weight, were significantly greater in the selenium treatments. Intra-egg injection of organic selenium produced favourable effects on performance of broiler chickens, although it had no effect on immune response or microbial population. However, the negative effect on hatching of chickens needs to be prevented to result in an acceptable economic return for the producer.

Effect of dawri‐damaa (Pentas schimperiana) leaf meal supplementation on performances, carcass characteristics, and economic feasibility of sheep fed native grass hay

AbstractWith a growing export and local market, sheep farming is critical to the economy of smallholder farmers; however, indigenous sheep breeds usually exhibit low carcass output and live weight due to nutritional constraints. The study aimed to investigate the impact of supplementing local sheep with dawri‐damaa leaf meal (DDLM) on their performance, carcass characteristics, and profitability when fed native grass hay. The research used a randomized complete block design (RCBD) to administer four feeding treatments (T1, T2, T3, and T4 at 0%, 30%, 50%, and 70% DDLM, respectively) to 20 local uncastrated male lambs having an average 23.72 ± 0.73 kg body weight and average age of 11.72 ± 0.74 months. Greater doses of DDLM in the diet resulted in greater average daily gain (ADG) of 51.4–83.8 g/day and feed conversion efficiency (FCE) of 0.066–0.089 in lambs, compared to 15.0 g/day ADG and 0.025 FCE in lambs under control diet (T1). Additionally, the lambs had increased slaughter body weight (SBW), empty body weight (EBW), and hot carcass weight (HCW) in T4 and T3 compared to other treatments (p &lt; .05). There were no significant differences in dressing percentages (DPs) across any treatment group. The study also discussed the economic viability of supplementing with DDLM, suggesting that feeding 70% daily dry matter of DDLM at 2.5% live weight might be beneficial depending on availability, access, and cost factors. In conclusion, feeding DDLM up to 70% has improved the performance of sheep and is economically feasible. Further research might be required to discover whether such levels of inclusion are harmful and apply different processing methods for feeding animals.

Addition of pyroligneous extract (wood vinegar) to the diet of growing and finishing pigs

The search for growth promoters from natural resources is essential for swine breeding. This study evaluated the effect of including different levels of eucalyptus wood vinegar (WV) in the swine diet on the performance, quantitative and qualitative characteristics of the carcass, and diarrhea index. Twenty-four crossbred females (Pietrain, Landrace, and Large White lines) were used, with an average initial weight of 31.2 + 5.6 kg. The animals received feed and water ad libitum. The feed was composed of corn, soybean meal, vegetable oil, and commercial supplement (evimix), and the dietary experiments consisted of rising levels of pyroligneous extract (0, 0.5, 1.0, and 1.5%). At the end of the experimental period (72 days), when the animals had an average weight of 97.5 kg, the following performance parameters were measured: daily feed consumption (DFC), daily weight gain (DWG), food recovery (FR), and quantitative and qualitative carcass limits. The results demonstrated no linear or quadratic effect (P&lt;0.05) on the growth phase between treatments. However, considering the total period (growth phase + termination) of the animals in the 1% group, they presented a linear effect (P&lt;0.05) for DFC but no significant effect for DWG and FR. There was no difference (P&lt;0.05) between quantitative and qualitative carcass values. Evaluation of the diarrhea index showed that the WV did not change like the animals' feces. So, WV can be used up to 1.5% of the diet of these animals without causing damage to performance or carcass quality, in addition to shortening the time to slaughter by 10%.&#x0D;  

Carcass and meat characteristics of Nellore young bulls fed diet using cottonseed cake as a replacer of the forage fiber source

The aim of this study was to assess the effects of substituting traditional forage fiber sources with cottonseed cake in the diet on both the quantitative and qualitative characteristics of carcass and meat in Nelore young bulls. Twenty-four Nelore steers starting with an average weight of 377.8 ± 43.5 kg, were individually housed in stalls and provided with individualized feeding over a 112-day confinement period. The study followed a completely randomized design with two treatments and 12 replications. The diets incorporated either whole plant corn silage (WPCS) and, cottonseed cake (CSC) as fiber sources, at a rate of 300 g/kg of dry matter. The CSC diet promoted higher carcass weight. Aging animal meat for seven days significantly decreased the shear force from 83.4 to 71.6 N. Although diets did not influence meat composition, WPCS diet provided higher concentrations of C16:1, C18:1n9c, C18:3n3, and C22:2 acid, and CSC diet higher concentrations of C15:0, C18:1n9t, C18:2n6c, and 20:3n3. The WPCS diet provided higher concentrations of monounsaturated fatty acids and ω9, and the CSC diet had higher concentrations of ω6 and ω6:ω3 ratio in meat. Cottonseed cake used as a fiber source increases the concentration of polyunsaturated fatty acids and ω6 fatty acids in the meat of young bulls finished in feedlot.

Potential of different strategies to increase intramuscular fat deposition in sheep: A meta-analysis study

We evaluated the potential of different strategies to increase intramuscular fat (IMF) deposition in sheep meat through meta-analytical methods. Additionally, this study aimed to investigate the interrelationship among diet composition, performance, carcass traits, meat quality, marbling score and IMF in sheep. The dataset was composed by 102 peer-reviewed publications. The strategies to increase IMF deposition in sheep meat were evaluated by examining the weighted mean difference (WMD) between control treatment and increased-IMF treatment (beta-agonist; glycerin; essential oil; vitamin E; lipids; tannins; feeding system and sex class). The interplay between factors such as dietary composition, performance, carcass and meat quality traits highlights how the intensification of production systems, characterized by a high grain content in the diet and shorter finishing periods, reduces IMF content of meat. The IMF content was greater in females (WMD = 0.52%; P<.0001) and castrated males (WMD = 0.53%; P = 0.001) compared to intact males. Lambs finished in feedlots exhibited a 19.23% higher IMF content (WMD = 0.74%; P <.0001) compared to those finished in pasture systems. The inclusion of lipids sources to the diets increased in IMF content (WMD = 0.11%; P = 0.008), while tannins sources decrease in IMF (WMD = -0.07%; P = 0.029). Marbling score did not prove to be an adequate indicator of IMF deposition in sheep meat, potentially due to biases in subjective marbling assessments. In conclusion, our findings suggest that the most effective strategy for enhancing IMF in lambs involves utilizing female or castrated males rather than intact males followed by finishing lambs on high concentrate diets in a feedlot. Genetics did not impact IMF in the evaluated studies while other dietary strategies to alter IMF deposition had mixed effects on IMF deposition. Tannin marginally decreased IMF, vitamin E had no effect, and lipid supplementation had varied effects on IMF deposition depending on the lipid source.

Influence of graded levels of maize distillers dried grains with solubles (mDDGS) on the performance, digestive tract development and carcass characteristics of broilers

Abstract The present study investigated the feeding value of maize distillers dried grains with solubles (mDDGS) for broiler chickens. As the first step, the nutrient composition, apparent metabolisable energy (AME) and apparent ileal amino acid digestibility of mDDGS were determined. These values were used to formulate iso-nutrient and isocaloric diets to evaluate the influence of graded levels of mDDGS on broiler performance, digestive tract development and carcass characteristics. Five maize-soybean based diets containing 0 or 5, 10, 15 and 20% of mDDGS, were formulated and cold-pelleted at 65 °C. Each diet was offered ad libitum to six replicates (eight birds per replicate cage) during starter (day 1–21) and finisher (day 22–35) phases. The mDDGS was analysed to contain (% dry matter (DM) basis): CP, 27.8; total non-starch polysaccharides, 28.6 and soluble non-starch polysaccharides, 5.6. The AME was determined to be 10.23 MJ/kg DM. The average ileal digestibility coefficient of indispensable AA was 0.826. The Inclusion of 20% mDDGS resulted in poorer (P &lt; 0.05) feed per gain (quadratic effect, P &lt; 0.05) during the starter period, but no negative effects (P &gt; 0.05) were observed finisher period and the overall production period (day 1–35). Feed intake and feed per gain (linear effect, P &lt; 0.05) decreased with increasing inclusions of mDDGS during finisher period and overall period. A tendency (P = 0.06) for linear improvement in excreta quality was observed with increasing inclusion levels of mDDGS. Relative digestive tract weights and carcass and breast meat yields were not influenced (P &gt; 0.05) by dietary treatments. A linear (P &lt; 0.05) decrease was observed for the relative lengths of jejunum, ileum and the small intestine. The results indicated that, when balanced for metabolisable energy and digestible amino acids, mDDGS can be incorporated into broiler starter and finisher diets up to 15 and 20%, respectively, with no adverse effects on live performance, carcass characteristics or excreta quality.

Complementing Plant and Animal Protein Sources for Broiler Production: Effects on Growth, Carcass Traits, and Economics

This study investigated the effects of complementing plant-based Sesbania grandiflora meal (SGM) and animal-based fermented golden apple snail extract (FGASE) protein sources on the growth performance, carcass characteristics, meat quality, and economic profitability of broiler chickens. A 2x4 factorial experiment was conducted, with SGM levels (0 and 15g kg-1) and FGASE levels in drinking water (0, 10, 20, and 30 mL L-1). SGM diet increased feed and water intake but did not affect final body weight or weight gain. FGASE in water did not influence feed or water intake. The combination of SGM and FGASE improved feed conversion ratio, but higher FGASE levels reduced dressing percentage. Neither SGM nor FGASE significantly impacted most meat cut weights or visceral organ weights, except for a significant interaction on back weight. Economic analysis revealed positive returns on investment for all treatments, with the highest net profit obtained from broilers fed a standard diet supplemented with 10 mL L-1 FGASE. The findings suggest the potential for incorporating SGM and FGASE in broiler diets to improve feed efficiency and profitability, though optimal inclusion levels and processing methods require further investigation.

Influence of feed intake management system on cattle intake and growth performance

Variation in feed intake systems and subsequent bunk management between research settings and the beef industry has increased over the last decade. Despite the need for both feed management application systems in the beef industry, a comparison of feed intake, cattle intake behavior, and growth performance between cattle fed in an open bunk system compared to an individual intake system has not been conducted. Therefore, the objective of this study was to evaluate feed intake, growth performance, and carcass characteristics of steers fed in an individual feed intake bunk system (FIMS) compared to a traditional, open bunk system. One hundred twelve crossbred yearling steers (n = 28 hd/pen) were randomly assigned to one of two treatment groups: 1) fed in individual feed intake systems (FIMS) or 2) fed in traditional open bunk system (OPEN) with 2 pens per treatment. Steers fed in FIMS were managed to allow for ad libitum feed access while steers fed in concrete open bunks were managed using the South Dakota State University 4-point bunk scoring system, targeting slick bunks or bunk score of 0 three to five days per week with the remainder of the days being bunk scores of &amp;frac12; to 1. Over the 103-day feeding period, no difference in body weight or growth performance were observed between the two treatment groups with a tendency for ribeye area to be smaller in steers fed in FIMS. Results of this study demonstrated minimal differences performance and carcass characteristics of steers fed in an open bunk system in comparison to an individual intake bunk system. However, additional research is needed to determine the impact of bunk feeding system on individual steer social behavior to account for variation within pen.

Xylanase Supplementation in Energy-deficient Corn-based Diets: Impact on Broiler Growth, Nutrient Digestibility, Chyme Viscosity and Carcass Proximates.

The goal of the current study was to investigate the impact of various concentrations of xylanase in energy-deficient corn-based diets on the growth performance, carcass characteristics, nutrient digestibility, and digesta viscosity in broilers from 7 to 35 days of age. A total of 280 seven-day-old Ross 308 broilers were randomly allocated to one of the five dietary treatments following a completely randomized design with 8 replicates and 7 birds per cage. The treatments were: i) positive control (PC, without xylanase); ii) NC-1 (80 kcal/kg ME reduced from PC); iii) NC-2 (100 kcal/kg ME reduced from PC); iv) NCX-1 (NC-1 + 2000 U/kg xylanase); and v) NCX-2 (NC-2 + 3000 U/kg xylanase). Body weight, weight gain, feed intake, and feed conversion ratio were determined weekly to evaluate growth performance. One bird per pen was sacrificed for ileal digesta collection to determine the viscosity and digestibility of energy, dry matter, crude protein on days 24 and 35, however breast and leg meat samples were obtained for proximate analysis (moisture, crude protein, fat, and ash) on day 35. Birds fed diets supplemented with xylanase regardless of the amount had higher (p<0.05) body weights, daily gains, and improved feed efficiency compared to NC diets all throughout the experimental period. Feed intake was not affected (p>0.05) by the addition of xylanase. Moreover, lowered (p<0.05) viscosity of the ileal digesta were observed upon xylanase inclusion in the diets compared to the birds fed NC diets on day 24. Ileal nutrient digestibility and meat proximate composition were not affected (p>0.05) by xylanase. The present study indicated that the xylanase at 2,000 U/kg and 3,000 U/kg levels compensates for the 80 kcal/kg and 100 kcal/kg dietary energy levels, respectively, without having adverse effects on the growth performance, carcass characteristics, nutrient digestibility, and digesta viscosity of broilers.

Effect of Gum Arabic (Acacia senegal) on Growth Performance, Carcass Quality and Health of Clarias gariepinus Juveniles

The effect of Gum Arabic (GA) on growth, carcass quality, blood parameters, gut morphometry, and organ histology of African catfish Clarias gariepinus was studied. Five isonitrogenous diets with inclusion levels of GA at 0 g/100 g (GA0; control), 5 g/100 g (GA5), 10 g/100 g (GA10), 15 g/100 g (GA15), and 20 g/100 g (GA20) were formulated in a 40% crude protein diet. Juveniles of C. gariepinus with average weight (7.35±0.48 g/fish) were stocked at 13 fish/25 L of water for 12 weeks in a completely randomized design and fed at 3% body weight daily. Growth indices showed GA10 improved the mean weight gain (69.88±8.89 g) and specific growth rate (2.76±0.14 %/day) while at (GA15); (GA20) growth was depressed. Carcass quality revealed dietary levels were superior to control with GA10 significantly different (p &lt; 0.05) amongst treatments in protein and fat content. Hematological profile showed variations; erythrocyte indices compared to control, while plasma chemistry of aspartate aminotransferase, alkaline phosphatase, and alanine aminotransferase showed no difference (p &gt; 0.05). Gut morphometrics varied with no particular pattern. At inclusion above GA5 the gill, liver, and kidney were affected histologically with no changes in the intestines of all treatments. Diet supplemented with gum arabic at 10 g/100 g improved indices of performance of C. gariepinus juveniles in this study.

Evaluation of non-additive genetic effects on carcass and meat quality traits in Korean Hanwoo cattle using genomic models

The traditional genetic evaluation methods generally consider additive genetic effects only and often ignore non-additive (dominance and epistasis) effects that may have contributions in genetic variation of complex traits of livestock species. The available dense single nucleotide polymorphisms (SNPs) panels offer to investigate the potential benefits of including non-additive genetic effects in the genomic evaluation’s models. Data from 16,971 genotyped (Illumina Bovine 50K SNP chip) Korean Hanwoo cattle were used to estimate genetic variance components and prediction accuracy of genomic breeding values (GEBV) for four carcass and meat quality traits: carcass weight (CWT), eye muscle area (EMA), back fat thickness (BFT) and marbling score (MS). Five different genetic models were evaluated through including additive, dominance and epistatic interactions (additive by additive, A×A; additive by dominance, A×D and dominance by dominance, D×D) successively in the models. The estimates of additive genetic variances and narrow sense heritabilities (ha2) were found similar across the evaluated models and traits except when additive interaction (A×A) was included. The dominance variance estimates relative to phenotypic variance ranged from 1.7 to 3.4% for CWT and MS traits, whereas, they were close to zero for EMA and BFT traits. The magnitude of A×A epistatic heritability (haa2) ranged between 14.8 and 27.7% in all traits. However, heritability estimates for A×D and D×D epistatic interactions (had2 and hdd2) were quite low compared to haa2 and were contributed only 0.0 to 9.7% of the total phenotypic variation. In general, broad sense heritability (hG2) estimates were almost twice (ranged between 0.54 and 0.68) the ha2 for all of the investigated traits. The inclusion of dominance effects did not improve the prediction accuracy of GEBV but improved 2.0 to 3.0% when epistatic effects included in the model. More importantly, rank correlation revealed that partitioning of variance components considering dominance and epistatic effects in the model would enable to re-rank of top animals with better prediction of GEBV. The present result suggest that dominance and epistatic effects could be included in the genomic evaluation model for better estimates of variance components and more accurate prediction of GEBV for carcass and meat quality traits in Korean Hanwoo cattle.

Dietary replacement of maggot meal for soybean meal: implication on performance indices, nutrient digestibility, nitrogen utilisation and carcass characteristics of grower rabbits.

A study was conducted to investigate the effect of replacing soybean meal (SBM) with maggot meal (MM) in growing rabbits' diets on their performance, nutrient digestibility, and carcass characteristics. In the 56 days feeding trials, sixty unsexed mixed breeds (New Zealand White x California) rabbits were allotted on a weight equalization basis into five dietary treatments where a standard corn-soybean meal based diet (0% of maggot meal) (MM0 diet) served as the while other diets had soybean meal replaced with MM at graded levels of 25, 50, 75 and 100% to give MM25, MM50, MM75, and MM100 diets respectively. Each treatment comprises of four replicates having three rabbits each (12 rabbits per treatment). Growth performance parameters were monitored and recorded weekly, carcass and organ weights evaluation was conducted on day 56. Nutrient digestibility commenced on the 56th day and lasted for 6 days. Feed and water were offered to the rabbits ad-libitum throughout the experimental period. All the performance parameters were significantly (P < 0.05) affected by MM inclusion in the diet of rabbits. Rabbits fed MM100 diet had the highest (P < 0.05) final weight (FW), total weight gain(TWG), and the best feed conversion ratio (FCR). The feed cost reduced (P < 0.05) with inclusion of MM in rabbit's diet. Feed cost per kg live weight (FC/LW) (1110.79 ₦/kg) and feed cost per kg weight gain (FC/WG) (1110.62 ₦/kg) was lowest (P < 0.05) for rabbits fed MM100 diet. Crude protein digestibility (CPD) (74.05%) was highest (P < 0.05) for rabbits fed the MM100 diet. The feeding of MM75 and MM100 diets to rabbits resulted in increased (P < 0.05) dry matter digestibility (DMD) (68.22 and 69.34%), nitrogen free extract digestibility (NFED) (65.52 and 65.22%) and neutral detergent fibre digestibility (NDFD) (70.05 and 69.58%). The highest (P < 0.05) nitrogen retained (NR) (2.10g/d) occurred in rabbits fed the MM100 diet. The dressing percentage (DP) (71.01%) increased (P < 0.05) for rabbits fed the MM100 diet. The weight of forelimbs (10.48 and 10.45%) and hind limbs (17.42 and 18.07%) were highest (P < 0.05) for rabbits fed MM50 and MM100 diets respectively. Total gastrointestinal tract (GIT) and liver weight were highest (P < 0.05)for rabbits fed MM0 and MM100 diets respectively. It was concluded that MM can conveniently replace SBM in the diets of rabbits up to 100% for improved growth performance and increased nutrient digestibility. In addition, it can enhance DP and increase the carcass yield of rabbits.

Carcass characteristics, physicochemical traits, texture and microstructure of young and spent quails meat

Carcass characteristics, physicochemical traits, texture and microstructure of young and spent quails meat

Effect of feeding Bengal gram residual forage-based pelleted total mixed ration on growth performance, nutrient availability, carcass traits and composition in finisher Barbari kids.

The study aimed to assess the impact of feeding Bengal gram residual forage-based pelleted Total Mixed Ration (TMR) with varying concentrate (C) to roughage (R) ratios on feed intake, nutrient utilization, growth, and carcass characteristics in Barbari kids. Sixteen weaned male Barbari kids (av. age, 233 ± 11 days; weight, 13.86 ± 0.76kg) were divided into two groups (T1 and T2), each receiving different pelleted diets (TMR) with distinct concentrate to roughage ratios (T1 with 60:40; T2 with 40:60). The kids were fed for 133 days, and a digestion trial was conducted at the end of the study. After completion, all kids were slaughtered. Although, kids under T1 consumed higher (P < 0.001) amount of dry matter, and crude protein compared to T2, which was due to a higher concentrate to roughage ratio in T1. But, the average daily body weight gain (ADG) of finisher kids was 88.53, and 79.83g/d/kid in T1 and T2, respectively; however, the difference was non-significant. Digestibility of organic matter, crude protein, and total carbohydrate was also greater in T1 compared to T2. Total digestible nutrients intake was higher (P < 0.001) in T1; similarly intake of digestible energy, and metabolizable energy were significantly increased (P < 0.01) in T1 compared to T2. Concentrations of volatile fatty acids and NH3-nitrogen were also enhanced (P < 0.05) in T1 compared to T2. We observed similar carcass weight, and dressing percentage in both groups, and carcass composition remained unaffected. The pelleted diet containing greater ratio of concentrate: roughage (60:40) had no additional benefits in terms of ADG, and carcass traits in finisher kids. Therefore, it may be concluded that the Bengal gram residual forage-based pelleted TMR diet containing C40: R60 (TDN 57.13%, DCP 7.64%, ME 9.11MJ/kg feed) is suitable for optimizing growth performance with desirable carcass traits, and meat composition in finisher Barbari kids reared under the intensive system.