Efficiency Of Feed Utilization Research Articles

Influence of Addition of Murbei (Morus alba L.) Flowers to Food for Fathering Mangrove CRABS (Scylla serrata) Apartment Systems

Mangrove crab (Scylla serrata) is one of the fishery commodities that has high economic value. In Indonesia, crab cultivation has been widely developed, it can be seen from the cultivation media used, namely using vertical crab houses (apartments) with the RAS system. However, the problem in the mangrove crab cultivation system lies in the feed, the lack of nutrients in the feed results in non-optimal crab growth so that it is less attractive to consumers and causes its economic value to decline. Therefore, alternative feed is needed in the form of feed pellets that are in accordance with the nutritional needs of mangrove crabs and the addition of feed raw materials in the form of mulberry leaf flour in feed that can stimulate the growth of mangrove crabs. Therefore, this study aims to determine the optimal dose of mulberry leaf flour for mangrove crab feed in stimulating growth. This study used an experimental method conducted using a completely randomized design (CRD) consisting of 5 treatments and 3 replicates. Treatments in this study include: A (Control), B (7.5%), C (15%), D (22.5%) and E (30%). The results showed that the administration of mulberry leaf flour with different doses in mangrove crab feed had a real effect (P<0.05) on the growth of absolute weight (W), absolute length (P), specific growth rate (SGR), feed conversion ratio (FCR) and feed utilization efficiency (EPP) and had no real effect (P>0.05) on the Survival Rate (SR). Treatment C (15%) is the best dose of mulberry leaf flour that can support the growth and survival of mangrove crabs. the highest values were W (14.6±2.6 d), P (0.6±0.3 b), SGR (0.34±0.06 s), FCR (18.39±3.50 a) and EPP (48.51±2.80 c).

Evaluation of black soldier fly (Hermetia illucens) larvae oil as a potential lipid source for largemouth bass (Micropterus salmoides): Growth performance, myofiber development and glucolipid metabolism

Black soldier fly larvae oil (BSFLO) is considered as a by-product of the production process of defatted black soldier fly larvae meal at present, and may show the potential to be used as a lipid source for aquafeeds. In this study, a total of 300 largemouth bass (initial body weight 7.95g) were fed diets containing different levels of BSFLO for 56 d to evaluate its effects on the growth performance, fatty acid composition, antioxidant capacity and glucolipid metabolism. Five isonitrogenous and isolipidic diets were designed with fish oil supplemented feed (FO) as the control diet and then feeds with BSFLO replacing 12.5%, 25%, 50% and 100% of the fish oil (BSFLO12.5, BSFLO25, BSFLO50, BSFLO100) as the treatment diets. No significant changes in weight gain and specific growth rate were observed between groups, but BSFLO100 showed a significant change in feed conversion ratio, higher than the control group (P < 0.05). The muscle and liver C12:0 and ∑n-6 PUFA content increased with the addition of BSFLO, while C20:5n-3, C22:6n-3 and ∑n-3 PUFA content gradually decreased, and significant differences were observed between FO and BSFLO100 (P < 0.05). Expression of hepatic Δ6fad and FABP genes was lower in the FO group and the highest in BSFLO50 and BSFLO100 (P < 0.05). In terms of myofiber development, Dietary BSFLO led to e a progressive increase in myofiber diameter and area, while the expression of smad-2 gene in muscle was significantly reduced in BSFLO25 and BSFLO50 (P < 0.05). Besides, the serum glucose levels were significantly lower in BSFO12.5, BSFLO50 and BSFLO100, and dietary 8% BSFLO (BSFLO100) resulted in a decrease in hepatic glycogen content from 94mgg-1 to 71.78mgg-1, along with the expression of glycolysis-related genes (GK, PK and PFK) and enzyme (PK and PFK) activities (P < 0.05), while the expression of gluconeogenesis-related genes (G6Pase) was significantly increased (P < 0.05). Dietary 4% BSFLO (BSFLO50) increased muscle and liver T-SOD activity and simultaneously reduced muscle MDA content (P < 0.05), which has the best antioxidant properties. One-variable linear regression analysis revealed that various parameters of feed utilization, glucose metabolism, and muscle development in fish were significantly and linearly affected by dietary BSFLO levels (P < 0.05). In summary, if only optimal glucose lowering is considered, 8% BSFLO is recommended. However, if feed utilization efficiency is taken into account, it is recommended that dietary BSFLO be added at no more than 4%.

Exploring the molecular basis of efficient feed utilization in low residual feed intake slow-growing ducks based on breast muscle transcriptome

Residual feed intake (RFI) has recently gained attention as a key indicator of feed efficiency in poultry. In this study, 800 slow-growing ducks with similar initial body weights were reared in an experimental facility until they were culled at 42 d of age. Thirty high RFI (HRFI) and 30 low RFI (LRFI) birds were selected to evaluate their growth performance, carcass characteristics, and muscle development. Transcriptome and weighted gene co-expression correlation network analyses of pectoral muscles were conducted on six LRFI and six HRFI ducks. The results revealed that selecting for LRFI significantly reduced feed consumption (P < 0.05) and improved feed efficiency without affecting the growth performance, slaughter rate, or meat quality of ducks (P > 0.05). Moreover, compared with HRFI ducks, LRFI ducks had a lower pectoral muscle fat content (P < 0.05), larger muscle fiber diameter and area (P < 0.05), and lower muscle fiber density (P < 0.05). There were significant differences in gene expression between LRFI and HRFI ducks, with 102 upregulated and 258 downregulated genes, which were enriched in the PPAR signaling pathway, adipocytokine signaling pathway, actin cytoskeleton regulation, ECM-receptor interaction, and focal adhesion. The expression of genes associated with fat and energy metabolism, including ACSL6, PCK1, APOC3, HMGCS2, PRKAG3, and G6PC1, was downregulated in LRFI ducks, and weighted gene co-expression correlation network analysis identified PRKAG3 as a hub gene. Our findings indicate that reduced mitochondrial energy metabolism may contribute to the RFI of slow-growing ducks, with PRKAG3 playing a pivotal role in this biological process. These findings provide novel insights into the molecular changes underlying RFI variation in slow-growing ducks.

Combined effects of vitamin E and temperature on the growth, biochemistry, and natural immune response of juveniles snubnose pompano (Trachinotus blochii)

This study investigates the combined effects of Vitamin E and temperature on the growth, biochemical composition, and immune responses of juvenile snubnose pompano (Trachinotus blochii). A 70-day experiment was conducted with six treatments combining two levels of dietary Vitamin E (0 and 400 mg/kg) and three temperature levels (28°C, 31°C, and 34°C). The results revealed that both temperature and Vitamin E significantly influenced growth performance, feed utilization efficiency, protein and lipid content, and certain immune parameters (P &lt; 0.05). Fish reared at 34°C with 400 mg/kg vitamin E demonstrated the highest growth indicators (SGRL, SGRW), protein efficiency, hepatosomatic index (HSI), and immune response, as indicated by elevated serum lysozyme levels, phagocytic activity, and white blood cells. Temperature notably affected lysozyme and respiratory burst activity, with values increasing at higher temperatures. Vitamin E supplementation improved these metrics regardless of temperature, increasing protein efficiency and reducing feed intake and feed conversion ratio (FCR). Moreover, Vitamin E enhanced immune responses, including increased white blood cell (WBC) counts and phagocytic activity. No interactive effects between Vitamin E and temperature were observed (P &gt; 0.05). Overall, Vitamin E (400 mg/kg) positively influenced growth, biochemical composition, and immunity in snubnose pompano, particularly at elevated temperatures. The findings demonstrate that dietary vitamin E can enhance growth and immune performance, particularly under elevated temperatures, providing a basis for optimizing vitamin E use in snubnose pompano aquaculture.

Dietary intervention of propolis and/or turmeric boosted growth, hematology, biochemical profile, and antioxidant-immune responses and their associated gene expression in Nile tilapia (Oreochromis niloticus) challenged with Edwardsiella tarda

Immunostimulant phytogenic feed additives are given great concern for improving fish health, growth, immune responses, and resistance to diseases. This research investigated the impact of dietary propolis (PRO), turmeric (TUR), and their combination on the growth, hematology, antioxidant-immune responses, and their regulating genes in Nile tilapia (Oreochromis niloticus) during Edwardsiella tarda challenge. For 8 weeks, a total number of 320 fish (20.70 ± 0.14 g) were allocated into four groups at random, each with eight replicates (10 fish each). The first group (1st) was given the basal diet (control) without any supplements. The 2nd, 3rd, and 4th groups were supplemented with 1% PRO, 1% TUR, and the mixture (1%PRO + 1%TUR), respectively. The experimental groups were challenged intraperitoneally with E. tarda at a dose of 0.1 mL (1 × 105 CFU) at the termination of the feeding trial, and the fish survival was estimated for an additional 7 days. The results demonstrated that fish-fed diets supplemented with PRO and/or TUR showed higher body weight, condition factor, specific growth rate, feed intake, and feed efficiency utilization than the control group (P < 0.05). The hematological, protein profile, and antioxidant-immune (total antioxidant capacity, lysozymes, and IgM) parameters were substantially improved in the challenged fish fed on PRO and/or TUR diets compared to the challenged non-fed fish. The lipid profile and malondialdehyde were substantially decreased in the challenged fish fed on PRO and/or TUR diets compared to the challenged non-fed group. Notably, a down-turning of nuclear factor kappa B (NFκB) and tumor necrosis factor-alpha (TNF-α) expression with up-turning of nuclear factor erythroid 2-related factor 2 (Nrf2) and transforming growth factor-beta (TGF-β) expression was noticed in the challenged fish fed on PRO and/or TUR diets compared to the challenged non-fed fish. Noteworthy, dietary PRO and/or TUR improved the fish survival during E. tarda challenge. The mixture of PRO and TUR can be added to Nile tilapia diets to enhance their growth, immune response, and resistance to E. tarda. These outcomes help in the sustainable development of the Nile tilapia culture industry.Graphical

Fermented Palm Kernel Cake Improves the Rumen Microbiota and Metabolome of Beef Cattle.

In this study, we utilised palm kernel cake as a substrate and fermented it with a composite of bacteria (Pediococcus pentosaceus CGMCC No. 27203 and Lactobacillus plantarum CGMCC No. 27202) and enzymes. We conducted a trial with twenty-four cattle, randomly divided into two groups of twelve cattle each. The control group (CON) was fed the standard farm diet, whereas the treatment group (PKC) received a diet with 3% of soyabean replaced by fermented palm kernel cake. The trial lasted for six weeks. The results showed no significant differences in growth performance between the PKC and CON groups. The abundance of Firmicutes, Bacteroidetes, Proteobacteria, and Spirochaetes was significantly higher in the PKC group than in the CON group. At the genus level, the abundances of Anaeroplasma, norank_f__Bacteroidales_UCG-001, norank_f__Absconditabacteriales_SR1, norank_f__p-251-o5, Prevotellaceae_NK3B31_group, Prevotellaceae_UCG-001, Prevotellaceae_UCG-004, and Treponema significantly increased in the PKC group. Lipid digestion and absorption pathways were significantly enriched in the PKC group. The results indicate that adding fermented palm kernel cake to the diet can increase the abundance of Bacteroidetes and Fibrobacteres in the rumen of beef cattle, enhancing the ability of the PKC group to degrade protein, carbohydrates, and fibrous materials in the feed, thereby improving the feed utilisation efficiency in beef cattle. Adding fermented palm kernel cake to the diet improved carbohydrate metabolism, metabolism of cofactors and vitamins, and nucleotide metabolism. Correlation analysis between the rumen microbiota and metabolic pathways showed that Prevotellaceae_UCG-001 and Prevotellaceae_UCG-003 were positively correlated with amino acid metabolism, Rikenellaceae_RC9_gut_group and Succiniclasticum were positively correlated with metabolism of cofactors and vitamins, and Prevotella and Ruminococcus were positively correlated with nucleotide metabolism. These findings elucidate the differences in rumen microbiota when fermented palm kernel cake is added to the diet, providing a theoretical basis for the application of fermented palm kernel cake in the diet of beef cattle.

Evaluating the Potential of Marine Algae as Sustainable Ingredients in Poultry Feed

Algae are a complex source of crucial nutrients, including proteins, minerals, vitamins, and carbohydrates. The use of marine algae, specifically Sargassum species, Gracilaria species, and Spirulina species, as feed ingredients in poultry feed was examined in the current research. This study’s aims were to carry out lipid profiling, proximate analysis, and heavy metal toxicity testing, as well as to evaluate the presence of hazardous hydrocarbons in the algae and investigate the effect of the fatty acid profile of Sargassum species on broilers. The proximate analysis was conducted on the algae types containing considerable quantities of fats and proteins and a sizable quantity of omega-3 fatty acids. This research assessed the productive effectiveness of broilers with 2.5%, 6%, and 10% algal additions in their diet. Fatty acid profiling of Sargassum species was performed at 1% and 2% levels in the bursa, fat pads, heart, liver, spleen, thymus, thighs, and breast. The findings showed no significant differences in the development performance or feed utilization efficiency of broilers with 2.5%, 6%, and 10% algae supplementation in their diet. The results of fatty acid profiling showed changes in the heart, liver, and spleen at 1% and 2% supplementations levels. However, this research concludes that if algae partially replaces the imported feed proteins used in animal feed, then these can achieve maximum beneficial effects on poultry health and performance. Algae are sustainable, easy to produce, and cost-effective sources of nutrients and contain numerous bioactive compounds, which will contribute to sustainability and food safety.

Effects of spent substrate of oyster mushroom (Pleurotus ostreatus) on ruminal fermentation, microbial community and growth performance in Hu sheep.

The study aimed to evaluate the effects of Pleurotus Spent Mushroom Substrate (P.SMS) on the rumen microbiota, encompassing bacteria and fungi, as well as their interactions in Hu sheep. A total of forty-five 3-month-old Hu sheep were randomly assigned to five groups. Each group was fed diets in which whole-plant corn silage (WPCS) was substituted with P.SMS at varying levels: 0% (CON), 5% (PSMS5), 10% (PSMS10), 15% (PSMS15), or 20% (PSMS20). The results indicated that higher proportions of P.SMS during the experimental period might have a detrimental effect on feed utilization efficiency, kidney function, and blood oxygen-carrying capacity. Notably, moderate levels of P.SMS, specifically below 15%, were associated with improvements in rumen NH3-N levels and absorption capacity. The results indicated that (1) PSMS20 exhibited a significantly higher feed-to-gain ratio compared to CON (P < 0.05); (2) PSMS15 showed a significantly higher NH3-N content than CON, PSMS5, and PSMS20. Additionally, PSMS10 and PSMS20 had elevated concentrations of NH3-N compared to CON and PSMS5 (P < 0.05); (3) The length and width of rumen papillae were significantly greater in PSMS20 compared to CON and PSMS5 (P < 0.05); (4) Creatinine levels were significantly higher in PSMS20 than in CON, PSMS5, and PSMS10 (P < 0.05); (5) By the conclusion of the experiment, hemoglobin concentration in PSMS20 showed a significant increase compared to CON (P < 0.05). Furthermore, the addition of P.SMS influenced microorganisms at both the phylum and genus levels: (1) At the phylum level, the prevalence of Patescibacteria was significantly lower in PSMS20 compared to the other groups; (2) PSMS15 exhibited significantly higher relative abundances of Basidiomycota compared to CON and PSMS10, while PSMS20 also demonstrated significantly higher relative abundances compared to CON (P < 0.05); (3) At the genus level, the prevalence of Candidatus_Saccharimonas in PSMS20 was significantly lower than in PSMS5, PSMS10, and PSMS15. Conversely, the prevalence of Phanerochaete in PSMS15 was notably higher than in CON and PSMS10, and it was also significantly elevated in PSMS20 compared to CON (P < 0.05); (4) Correlation analysis indicated no significant correlation between changes in the structure of bacterial and fungal communities. Considering these findings, a high percentage of P.SMS negatively impacted feed utilization efficiency, blood oxygen carrying capacity, and kidney function, while a moderate percentage of P.SMS promotes rumen absorption capacity, indicating that feeding 10% P.SMS is optimal.

The Effect of Saccharomyces cerevisiae in Commercial Feed on Feed Utilization Efficiency, Growth Performance, and Blood Profile of Freshwater Pomfret (Colossoma macropomum) Fingerlings

The Effect of Saccharomyces cerevisiae in Commercial Feed on Feed Utilization Efficiency, Growth Performance, and Blood Profile of Freshwater Pomfret (Colossoma macropomum) Fingerlings

Safety Assessment of Camelid-Derived Single-Domain Antibody as Feed Additive for Juvenile Whiteleg Shrimp (Litopenaeus vannamei) Against White Spot Syndrome Virus.

A six-week feeding trial was conducted to assess the safety of single-domain antibodies (sdAbs) derived from camelids against the white spot syndrome virus (WSSV) (WSSVvp28 was used as the antigen), focusing on the whole-organism responses and molecular-level changes in juvenile whiteleg shrimp (Litopenaeus vannamei). Five experimental diets with varying levels of sdAbs were formulated: CON (no sdAb supplementation); SDA8.2 (8.20% of sdAbs); SDA16.4 (16.40% of sdAbs); SDA24.6 (24.60% of sdAbs); and SDA32.8 (32.80% of sdAbs). In the CON diet, 450 mL of water per kg of diet (45%) was used to form a feed dough, while sdAbs were used to replace the water in the treatment diets. A total of 450 shrimp, with an initial body weight of 3.27 ± 0.02 g (mean ± SEM), were randomly distributed in 15 tanks (30 shrimp per tank; three tanks per treatment). Each tank was filled with 30 L of seawater (77 L capacity) in an indoor semi-recirculating system with a constant water flow rate of 1.2 L min-1. The photoperiod was maintained at 12 h of light and 12 h of dark. The water temperature, pH, salinity, and dissolved oxygen were 27.3 ± 0.1 °C, 7.61 ± 0.01, 34 ± 1 ppt, and 5.94 ± 0.04 mg L-1, respectively. During the feeding trial, the shrimp were fed the experimental diet (40% protein and 11% lipid) three times a day for six weeks. Following the feeding trial, an acute cold-water-temperature stress test was conducted by abruptly exposing the shrimp from each treatment to 15 °C for 4 h, down from 27 °C. The results showed no significant differences in the growth performance (weight gain, feed utilization efficiency, survival, etc.), plasma metabolites (aspartate aminotransferase activity, alanine aminotransferase activity, total protein, and glucose), or antioxidant enzymes (superoxide dismutase and glutathione peroxidase) among all the experimental diets (p > 0.05). In the acute cold-temperature stress test, there was no significant interaction between sdAb supplementation and temperature stress, nor any main effect from either factor, except for the main effect of temperature stress on the glucose levels, which was significantly higher in shrimp exposed to cold-temperature stress (p < 0.05). The next-generation sequencing of differentially expressed genes (DEGs) in the hepatopancreases of shrimp fed the CON, SDA16.4, and SDA32.8 diets, followed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, indicated that DEGs were significantly enriched in signaling pathways associated with growth, cold stress, and antioxidant systems. Overall, the results from conventional measurements suggest that the use of sdAbs against the WSSV may be safe for juvenile whiteleg shrimp. However, findings from the sophisticated analysis indicate that further research is needed to understand the molecular mechanisms underlying the observed changes, and to evaluate the long-term effects of sdAb supplementation in shrimp diets.

The Effect of Phytase Enzyme in Feed on Growth Performance, Feed Utilization Efficiency, and Survival Rate of Milkfish (Chanos chanos) Fingerlings

The aim of this study was to evaluate the effect of phytase enzyme supplementation on the growth performance, feed utilization efficiency, and survival rate of milkfish fingerlings. The experimental fish used in this study were milkfish fingerlings with an average weight of 2.89±0.46 g per fish. The feed used in this research was a formulated pellet feed containing 30% protein, with added phytase enzyme. The treatments consisted of different phytase enzyme doses, namely A (0 mg/kg feed), B (250 mg/kg feed), C (500 mg/kg feed), and D (750 mg/kg feed). The results showed that different doses of phytase enzyme in the feed significantly affected (P&lt;0.05) growth performance and feed utilization efficiency but did not significantly affect (P&gt;0.05) the survival rate of milkfish fingerlings. The optimal dose of phytase enzyme for improving growth performance and feed utilization efficiency in milkfish fingerlings was between 502-665 mg/kg feed, resulting in a maximum total feed consumption (TFC) of 140.43 g, Feed Conversion Ratio (FCR) of 1.18, feed efficiency (FE) of 78.16%, protein efficiency ratio (PER) of 2.6, and relative growth rate (RGR) of 4.43%.

Dietary curcumin supplementation enhances growth performance and anti-inflammatory functions by modulating gut microbiota, microbiota-derived metabolites, and expression of inflammation-related genes in broilers.

Curcumin (CUR) is a natural polyphenolic substance that has been widely used since ancient times for its multiple beneficial functions. However, whether CUR affects growth performance of broilers by altering gut microbiota and metabolite and the underlying mechanism are largely unknown. This study was conducted to evaluate the effect of dietary CUR supplementation on growth performance, anti-inflammatory function, intestinal morphology and barrier, cecum microbiota and metabolite profile of broilers. Sixty 1-day-old male broilers were randomly divided into control group (CON, fed a control diet) and CUR group (fed a control diet supplemented with 200mg/kg CUR) after 2 days of adaptation. Results showed that after feeding to 52-day-old, compared with CON broilers, the CUR broilers showed improved feed utilization efficiency and growth performance. Furthermore, the CUR broilers showed an improved intestinal morphology, which was demonstrated by a lower crypt depth in the jejunum. The 16S rRNA gene sequencing and non-targeted metabonomics (LC-MS/MS) analysis results showed that the cecum microbiota ecology and function were significantly improved, and the abundance of beneficial flora and metabolites were increased, while the harmful bacteria and metabolites were significantly decreased. In addition, RT-qPCR results showed that CUR significantly reduced inflammatory responses, promoted the formation of the mucosal barrier and enhanced digestion, absorption and transport of lipids and glucose related genes expression in the intestine. These above findings demonstrated that dietary CUR supplementation improved growth performance, intestinal morphology and anti-inflammatory functions, mainly by manipulating cecum microbiota and microbiota-derived metabolites, which provides a credible explanation for the growth-promoting effect and anti-inflammatory functions of CUR and aids our understanding of the mechanisms underlying.

Interactions between feed protein source and feeding frequency on growth performance and health status of largemouth bass (Micropterus salmoides).

In order to evaluate the effects of the interaction between different proteins and feeding frequency on largemouth bass (Micropterus salmoides) and to provide scientific guidance for the application of novel proteins and the corresponding optimal feeding strategy, a two-factorial design (5 × 3) with five protein feeds (fishmeal (FM), Clostridium autoethanogenum protein (CAP), Tenebrio molitor (TM), Chlorella meal (ChM), cottonseed protein concentrate (CPC)), and three feeding frequency (1, 2, and 3 times/d; FF1, FF2, FF3) was designed in culturing largemouth bass (initial weight, 2.98 ± 0.22g/fish) for 8weeks. Z-score combined with cluster analysis was used to analyze and compare the effects of different treatments on different indicators, such as growth performance, feed utilization, antioxidant capacity, and immune response to draw a general picture of the relationship among all these massive biomarkers. The results showed that different protein sources and feeding frequencies had significant interactive effects on growth performance, feed utilization efficiency, body lipid, and health status of largemouth bass. Fish fed with ChM feed showed similar performance to that in FM group, implying its potential for complete replacement of fishmeal in largemouth bass. Fish fed with CAP, TM, and CPC feeds showed worse performance compared to FM and ChM groups, characterized by poor growth and feed utilization, enhanced stress, chronic inflammation, and varying symptoms of histological changes in the liver and intestine, which demonstrated the adverse effects of the complete replacement of fishmeal by these three proteins. In terms of feeding frequency, fish fed with FM feed in FF3 group led to liver hypertrophy, fat accumulation, and the risk of fatty liver, while inducing liver inflammation. In addition, the TM and CAP group had the higher expression levels of inflammatory factors at FF3 group, which displayed that the interactions between FM, CAP, TM feeds and feeding frequency at FF3 might aggravate the occurrence of liver inflammation and oxidative damage of hepatocytes. Overall, FF2 had higher feed efficiency, protein efficiency, antioxidant enzyme and lysozyme activities, lower MDA content, and lower gene expression of inflammatory cytokines and could be considered as the optimum feeding frequency for largemouth bass fed with different protein feeds.

191 Awardee Talk: Characterizing biological processes influencing the efficiency of nutrient utilization in growing cattle

Abstract 2Abstract: Residual feed intake (RFI), a metric of feed efficiency, is moderately heritable and minimally associated with body size and productivity, making it an ideal trait for investigation as a selection criterion to improve feed efficiency of growing cattle. The objective of this research was to characterize the inter-animal variation in biological processes of growing cattle selected to be divergent in RFI. Holstein heifers [n = 55; body weight (BW) = 351 ± 64 kg) with low- (n = 29) or high- (n = 26) genomically enhanced RFI (RFIg) were selected from a contemporary group of 453 heifers. Heifers were assigned to 1 of 2 pens, equipped with electronic feed bunks and a GreenFeed gaseous-exchange measurement system. Individual dry matter intake (DMI) and feeding behavior data were collected for 84-d. Body weight was measured weekly, and spot fecal samples collected at weighing. Phenotypic RFI (RFIp) was calculated as the residual from regression of DMI on ADG and mid-test BW0.75. On d 70 of the study a rumen fluid sample was collected via esophageal tubing. Blood samples were collected and analyzed for complete blood count (CBC). A mixed model including the fixed effect of RFIg classification and random effect of pen was used to evaluate the effect of RFIg classification on response variables. There were no differences (P &amp;gt; 0.05) in BW and ADG for heifers with divergent RFIg; however, low RFIg heifers consumed 7.5% less (P &amp;lt; 0.05) feed per day. Consequently, low RFIg heifers exhibited a more favorable (P &amp;lt; 0.05) RFIp (-0.188 vs 0.211 kg/d, respectively). Low RFIg heifers exhibited more favorable feeding behavior, with 8.7% fewer (P &amp;lt; 0.05) bunk visit events per day and an 11.2% slower (P ≤ 0.05) eating rate. Low RFIg heifers had 12.5% greater (P &amp;lt; 0.05) total rumen volatile fatty acid concentrations than high RFIg heifers, indicating potentially enhanced microbial fermentation and improved efficiency of feed utilization. Low RFIg heifers had 8.2% less (P &amp;lt; 0.05) methane emissions (g/d), 6.3% less (P &amp;lt; 0.05) carbon dioxide production (g/d), and 6.1% less (P &amp;lt; 0.05) heat production (Mcal/d) calculated according to Brouwer (1965) than high RFIg heifers. Dry matter digestibility did not differ (P &amp;gt; 0.05) between heifers with divergent RFIg. Overall, heifers selected to be more feed efficient exhibited more favorable energy efficiencies and feed efficiency phenotypes. To quantify the variation in RFIg explained by feeding behavior, gas flux, digestibility and rumen fermentation, and CBC partial least squares regression models were developed. Feeding behavior accounted for the largest proportion of variation in RFIg (28.8%). Upon sequential addition of gas flux, digestibility and rumen fermentation, and CBC to feeding behavior, 56.3% of the variation in RFIg was accounted for. Identifying the magnitude at which metabolic processes influence inter-animal variation in efficiency of nutrient utilization provides opportunities to discover valuable candidate biomarkers for selection of more feed efficient cattle.

RESPONSE OF BROILER CHICKENS TO VARYING LEVELS OF DIETARY BENZOIC ACID

An eight-week study was conducted to evaluate the response of broiler birds to varying levels of dietary benzoic acid. A total of one hundred and twenty (120) day-old unsexed “Arbor acre” strain broiler chicks were randomly assigned into five treatment groups. Each treatment group contained 24 birds replicated three times with eight birds per replicate in a completely randomized design (CRD). The treatments were designated as follows: Treatment 1,0g benzoic acid; Treatment 2, 2.5g benzoic acid per kg of feed; Treatment 3, 5.0g benzoic acid per kg of feed; Treatment 4, 7.5g benzoic acid per kg of feed and Treatment 5, 10g benzoic acid per kg of feed. Parameters assessed include final body weight (FBW), total weight gain (TWG), daily weight gain (DWG), total feed intake (TFI), daily feed intake (DFI) and feed conversion ratio (FCR). Feed and water were provided ad libitum. The results showed significant (p&lt;0.05) differences among treatments in FBW, TWG, DWG, TFI, DFI and FCR values. The FBW, TWG and DWG values increased significantly (p&lt;0.05) as the levels of benzoic acid in the diet increased from 0g to 7.5g. Birds fed diet containing 5g of benzoic acid per kg of diet (treatment3) had the highest (p&lt;0.05) FBW, TWG and DWG values (3380.71g, 3341.50g and 59.67g, respectively) but these values were similar to the FBW, TWG and DWG values (3236.98g, 3197.27g and 57.09g, respectively) recorded for birds in treatment2 (2.5g of benzoic acid per kg of diet). Birds fed diets containing 2.5g, 5g and 7.5g of benzoic acid had better efficiency of feed utilization as shown by their FCR values (1.89, 1.86 and 1.92, respectively) as compared to the FCR value(2.15) for birds fed the control diet. It was concluded that up to 7.5g of benzoic acid can be included in the diet of broiler birds for optimum growth performance without any deleterious effect on birds.

EVALUATION OF THE PERFORMANCE TRAITS OF CROSSES OF BROILER CHICKENS AND FULANI ECOTYPE CHICKENS

An experiment was conducted to evaluate the performance of hybrid chickens developed by crossing broiler parent stock and Fulani ecotype chickens. Two hundred (200) 1-day-old chicks were randomly allotted to 5 treatments. Each treatment had 4 replicates and each replicate had 10 birds. The experimental design was Randomised Complete Block Design. The treatments were Treatment 1: Commercial broiler chickens, Treatment 2: Commercial Noiler chickens, Treatment 3: Hybrid chickens developed by crossing broiler cocks with Fulani hens (Hybrid line 1), Treatment 4: Hybrid chickens developed by crossing Fulani cocks with broiler hens (Hybrid line 2) and Treatment 5: Fulani chickens. The experiment had both starter and finisher phases and lasted 10 weeks. The initial weights of the chicken genotypes reflected the sizes of their dam lines and the weights of the eggs they were hatched from. Genotypes with least initial weights had Fulani ecotype hens as their dam lines. The hybrid crosses T3 and T4 had better weight gain and final weights than the Noiler and Fulani ecotypes though lower than the commercial broilers (T1). Efficiency of feed utilisation followed the same trend. The carcass characteristics of the hybrids were also better than that of the Noiler and Fulani ecotypes as they laid more meat on their breasts.

UNDERSTANDING THE IMPACT OF DIET, HOST GENETICS AND EARLY LIFE INTERVENTIONS ON RUMEN MICROBIOME

The rumen microbiome often considered as the ruminant's second genome, facilitates the transformation of low quality feeds into high quality protein food (meat and milk) and other valuable animal products. These microbes alter the ruminal environment and help produce substrates for the host’s energy and body requirements. Several key factors influence rumen microbiota and fermentation, including diet, host genetics, and early life interventions. The potential to manipulate the rumen microbiome and meet global livestock challenges through animal breeding and introduction of dietary interventions during early life have recently emerged as promising new technologies. Advances in computational tools, high-throughput sequencing technologies and cultivation-independent “omics” approaches have provided profound insights into the rumen microbiome world, wherein a consortium of archaea, bacteria, protozoa, fungi, and viruses exist and interact. This will ultimately provide the knowledge framework needed to solve current and future ruminant livestock challenges. Understanding the effect of diet, host genetics, and early life interventions on the rumen microbiome is crucial for optimizing ruminant animal health, productivity, and efficiency of feed utilization while minimizing the environmental impact of ruminant production.

Application Of Microbubble Technology To Increase Oxygen Content In The Aquaculture Of Tambaqui (Colossoma Macropomum)

The oxygen consumed is used to oxidize food substances to produce energy. Therefore, the metabolic rate is usually indicated by the rate of oxygen consumption per time unit. In most intensive aquaculture systems, oxygen content is widely used due to the high stocking density and maximum feeding rates. This study aimed to evaluate the growth performance of freshwater pomfret (Colossoma macropomum) treated with increased oxygen in two different systems. The study was conducted in a laboratory scale by applying T-test data analysis. The difference of treatment level applied in the comparison of aeration and microbubble consists of two treatments and three replications. The researcher used commercial floating pellets PF0 with 25% protein content, the feeding rate was 5% of the biomass. The feed was given daily during the culture for two times a day. Data of the study were analyzed using T-test on the Statistical Product and Service Solutions (SPSS) software Version 17.0. Results of the study showed that aeration system using microbubble resulted in dissolved oxygen (DO) of 6.5 ± 0.17, 100% pomfret fish survival rate (SR), Survival Growth Rate (SGR) of 1.83 ± 0.24, Feed Conversion Ratio (FCR) of 1.37 ± 0.17, Protein Efficiency Ratio (PER) of 2.79 ± 0.37, Feed Utilization Efficiency (FUE) of 0.67 ± 0.09, Absolute Weight Growth of 52.02 ± 1.60; it was better than using aeration. This study has developed a model of freshwater pomfret fish aquaculture to provide growth value.

Effects of Low-Pressure Systems on Temperature, Humidity, Egg Production, and Feed Utilization Efficiency in Large-Scale Poultry Houses during Summer.

Low-pressure systems (LPSs) are among the most critical weather systems, producing excessive precipitation that causes air temperatures to drop and rise considerably. Acute temperature changes directly affect poultry feed intake (FI) and laying performance. To explore the effects of LPSs on hens, the parameters of air temperature, relative humidity, egg production, and feed utilization efficiency were evaluated during different LPSs in three houses. Results indicated that about 2.8 ± 0.7 d, 2.4 ± 0.5 d, and 2.4 ± 0.5 d before the LPS landfall in houses 1, 2, and 3, respectively, the indoor air temperature started to decrease, with the average decreases being 1.7 °C ± 0.4 °C, 2.4 °C ± 0.6 °C, and 1.8 °C ± 0.4 °C, respectively. Significant differences were observed between different LPSs for reducing indoor air temperature (p < 0.05) in the three houses. In house 1, the egg production rates (EPRs) were decreased by 6.6% and 1.1% when LPSs 1 and 2 landed. The average egg weight (AEW) and FI during the LPS landfall were significantly higher than those before the LPS landfall (p < 0.01). Under successive LPSs landfall in the three houses, the EPRs initially reduced by 3.9%, 4.0%, and 0.5%, respectively, but the second LPS event increased the EPRs by 1.8%, 5.3%, and 1.0%, respectively. Furthermore, the LPS landfall increased the feed conversion ratio (FCRe) in the three houses, all above 2.00. In conclusion, LPSs can reduce heat stress, lower the EPRs, and lead to higher FI, FCRe, and AEW.

Tank color affects growth, feed utilization efficiency, coloration, and biochemical composition of juvenile giant trevally (Caranx ignobilis Forsskål, 1775)

Tank color affects growth, feed utilization efficiency, coloration, and biochemical composition of juvenile giant trevally (Caranx ignobilis Forsskål, 1775)