Improved Feed Efficiency Research Articles

Does the Use of the Yeast Probiotic Saccharomyces cerevisiae Actisaf Sc 47 Reduce the Environmental Impacts of Beef Cattle? A Study Based on Life Cycle Assessment

Increasing animal protein, especially from beef, is necessary to satisfy the requirements of the growing global population. However, this is becoming increasingly challenging due to stakeholders prioritizing sustainable systems with low environmental impacts. To answer these challenges, the use of feed additives such as yeast probiotics seems to be an effective route for improvements in feed efficiency and growth performance. The current study was performed to quantify the environmental impacts of the production and use of a yeast probiotic (Actisaf® Sc 47) through an LCA method in four trials performed during the fattening period: France (French trial), Spain (Spanish trial), and Italy (Italian trials A and B). During each trial, two groups of animals with the same characteristics were compared during the fattening period: the control group without Actisaf® Sc 47 supplementation used as a baseline, and the experimental group with Actisaf® Sc 47 supplementation. The calves started the trial at the ages of 224, 92, and 186 days during the French, Spanish, and Italian trials A and B, respectively. Of the sixteen impact category indicators, nine were analyzed. In Italian trials A and B, the Spanish trial, and the French trial, the use of Actisaf® Sc 47 reduced CC by 4.8, 3.8, 6.6, and 5.4%; FE by 4.8, 3.9, 8.2, and 6.3%; ME by 4.9, 4.0, 6, and 6.4%; and TE by 5.3, 4.1, and 6.2%, respectively. Moreover, during the same trials, Actisaf® Sc 47 reduced AC by 6.0, 4.1, 6.3, and 7.1%; LU by 4.7, 3.9, 5.8, and 6.1%; WU by 4.5, 3.4, 5.2, and 5.9%; RU (fossils) by 4.8, 3.7, 7.3, and 4.8%; and PM by 5.2, 4.1, 6.3, and 7.1%, respectively. The use of Actisaf® Sc 47 has beneficial effects on the environment. Regarding Actisaf® Sc 47 production, the results showed that the production of 1 kg of Actisaf® Sc 47 emitted 2.1 kg of CO2 eq, 60% of which came from the fermentation process and 39% from drying. The results demonstrate the interest in using Actisaf® Sc during the fattening period for its multiple positive outcomes: improving performance and efficiency, while reducing the global carbon footprint.

Effect of a Bacillus subtilis-based direct-fed microbial, on milk yield, milk components, feed intake and plasma hormones and metabolites in lactating Holstein cows

To investigate the effects of a Bacillus-based direct-fed microbial on milk production and related factors, a study was conducted on Holstein cows (n = 28) starting at 90 ± 11 DIM. The cows were divided into two dietary groups: a control group (CON) that received a total mixed ration (TMR), and a Bacillus-fed group (DFM) that received the same TMR along with a Bacillus subtilis product containing two strains (747 and 1781) in equal amounts. The study lasted for 25 wk and included both primiparous and multiparous cows. The cows were housed in a free-stall barn and were provided with ad libitum TMR, which was fed twice a day. Their daily meals and dry matter intake (DMI) were recorded during wk 1–4 and wk 19–25 using electronic feeders. Milk samples were collected weekly during morning and evening milkings and analyzed for milk fat, protein, lactose, and milk urea nitrogen (MUN). Blood samples were also collected weekly and analyzed for plasma glucose, insulin, cholesterol, insulin-like growth factor 1 (IGF1), and progesterone concentrations. Additionally, rumen fluid samples were collected and evaluated for various species of bacteria. One of the key findings was that daily 4 % fat-corrected milk production (FCM) was influenced by the interaction between treatment (DFM vs. CON) and parity (primiparous vs. multiparous), with multiparous DFM cows producing 11 % more FCM compared to CON. The DFM cows also had a higher milk fat percentage (4.41 % vs. 4.02 %) and MUN concentrations were 1.0 mg/dL higher in the DFM group. In terms of blood metabolites and hormones, multiparous DFM cows had lower plasma cholesterol, glucose, and insulin concentrations compared to CON multiparous cows. However, there were no significant differences between the groups in terms of plasma IGF1 concentrations, insulin-to-glucose ratios, and luteal phase plasma progesterone concentrations. The analysis of rumen fluid samples revealed that the abundance of Ruminococcus albus and Fibrobacter succinogenes group I was greater in the DFM cows compared to CON cows. Furthermore, during the periods when feed intake was measured, the DFM cows had a 9 % reduction in feed intake and a 14 % improvement in feed efficiency (FCM per DMI) compared to CON cows. In conclusion, the two-strain Bacillus product used in this study (Certillus) showed potential as an effective direct-fed microbial. It was found to increase feed efficiency and milk production by altering the composition of ruminal microbiota and metabolism in the cows.

Effects of fermented Chinese herbal medicine feed additives on growth performance and intestinal microbiota of piglets.

Fermented Chinese medicine (FCM), as a functional feed additive, has been widely recognized to play a significant role in protecting the intestinal health of piglets and enhancing productive performance. However, the relationship between the active components of FCM, gut microbiota, and their beneficial effects on animal performance remains unclear. In this study, metabolomics analysis revealed a significant increase in the main contents of lactic acid and propionic acid in FCM, while most glycosides and their derivatives decreased after three days of microbial fermentation. Subsequently, piglets were fed a basic diet supplemented with 1% FCM, while the control group received only the basic diet. The results indicated a significant increase in feed intake and average daily gain within 14 days (P<0.05) due to FCM supplementation. Additionally, FCM significantly improved feed efficiency from 1.76 to 1.50 (P<0.05), and piglets in the FCM group exhibited significantly lower frequencies of diarrhea and coughing, which indicated improved health condition by FCM. Moreover, high-throughput sequencing analysis revealed higher abundances of Lactobacillus agilis, Megasphaera elsdenii, Ligilactobacillus, and Veillonellaceae in FCM group. In summary, FCM increased the content of active metabolites through microbial fermentation and regulated the intestinal microbiota to improve the health of piglets. FCM offers a promising potential for enhancing production performance and economic efficiency in the livestock industry.

Differential expression of nuclear-derived mitochondrial succinate dehydrogenase genes in metabolically active buffalo tissues.

Buffaloes are crucial to agriculture, yet mitochondrial biology in these animals is less studied compared to humans and laboratory animals. This research examines tissue-specific variations in mitochondrial succinate dehydrogenase (SDH) gene expression across buffalo kidneys, hearts, brains, and ovaries. Understanding these variations sheds light on mitochondrial energy metabolism and its impact on buffalo health and productivity, revealing insights into enzyme regulation and potential improvements in livestock management. RNA-seq data from buffalo kidney, heart, brain, and ovary tissues were reanalyzed to explore mitochondrial SDH gene expression. The expression of SDH subunits (SDHA, SDHB, SDHC, SDHD) and assembly factors (SDHAF1, SDHAF2, SDHAF3, SDHAF4) was assessed using a log2 fold-change threshold of + 1 for up-regulated and - 1 for down-regulated transcripts, with significance set at p < 0.05. Hierarchical clustering and differential expression analyses were performed to identify tissue-specific expression patterns and regulatory mechanisms, while Gene Ontology and KEGG pathway analyses were conducted to uncover functional attributes and pathway enrichments across different tissues. Reanalysis of RNA-seq data from different tissues of healthy female buffaloes revealed distinct expression patterns for SDH subunits and assembly factors. While SDHA, SDHB, and SDHC showed variable expression across tissues, SDHAF2, SDHAF3, and SDHAF4 exhibited tissue-specific profiles. Significant up-regulation of SDHA, SDHB, and several assembly factors was observed in specific tissue comparisons, with fewer down-regulated transcripts. Gene ontology and KEGG pathway analyses linked the up-regulated transcripts to mitochondrial ATP synthesis and the respiratory electron transport chain. Notably, tissue-specific variations in mitochondrial function were particularly evident in the ovary. This study identifies distinct SDH gene expression patterns in buffalo tissues, highlighting significant down-regulation of SDHA, SDHB, SDHC, and assembly factors in the ovary. These findings underscore the critical role of mitochondria in tissue-specific energy production and metabolic regulation, suggest potential metabolic adaptations, and emphasize the importance of mitochondrial complex II. The insights gained offer valuable implications for improving feed efficiency and guiding future research and therapies for energy metabolism disorders.

Effect of Long-Term Supplementation of AZOMITE (Hydrated Sodium Calcium Aluminosilicate) in Finishing Diets on Growth Performance, Dietary Energy, and Carcass Yield of Hairy Lambs.

The aim of this study was to evaluate growth performance, dietary energy utilization, and carcass characteristics (carcass weight, dressing percentage, and visceral organ mass) of feedlot lambs fed different levels of AZOMITE (AZO), a source of volcanic clay composed of hydrated sodium calcium aluminosilicate, the same as that included in a finishing diet. For this reason, 36 Pelibuey × Katahdin crossbred intact male lambs (18.81 ± 3.04 kg initial weight) were used in a feeding trial lasting 81 d. Lambs were grouped by initial weight and assigned within six weight groupings to 18 pens in a randomized complete block design. Diets, offered ad libitum, were corn-based finishing diets with an 88:12 concentrate-to-forage ratio supplemented as follows: 1) no AZO inclusion (CTRL), 2) AZO inclusion at a 0.75% level (0.75AZO) in diet dry matter, 3) AZO inclusion at a 1.50% level (1.5AZO) in diet dry matter. Cracked corn was replaced by AZO. After the feeding trial was finished, lambs were slaughtered and carcass weight was registered and dressing percentage was calculated. The data were analyzed as a randomized complete block design, with the pen as the experimental unit. Water consumption and dry matter intake were not affected (p ≥ 0.11) by supplemental AZO. The incorporation of AZO into the diet increased gain efficiency and observed dietary net energy (NE), being maximal with 0.75% AZO inclusion (quadratic effect, p = 0.02). The observed-to-expected dietary NE in the control group was as anticipated (1.00) according to the estimated energy based on the ingredient composition in diet, while in the 0.75AZO group, the observed dietary energy was 6% above expected, indicating a greater efficiency in energy utilization destined to growth (quadratic effect, p = 0.006). Lambs that were fed the AZO treatment showed an improvement (linear effect, p = 0.04) in hot carcass weight (HCW), and tended (linear effect, p = 0.06) to improve dressing percentage (DP) as AZO was increased in the diet. Visceral organ mass was not affected by the treatments. It is concluded that AZOMITE clay can be included up to 1.5% in finishing diets for lambs without negative effects on the intake of water and feed. Lambs that received diets supplemented with 0.75% AZO showed greater improvements in feed efficiency and dietary energy utilization, but an inclusion of 1.50% resulted in greater improvements to HCW and DP. This is the first report regarding the effects of AZO supplementation in the dietary energy utilization of fattening hairy lambs. Further research about the effects of AZO supplementation on ruminal and total tract digestion, carcass and meat quality, and the health of lambs is needed in order to more deeply understand the effects of AZO on its productivity performance.

Advanced chelate technology-based trace minerals reduce inflammation and oxidative stress in Eimeria-infected broilers by modulating NF-kB and Nrf2 pathways

This study investigated the effects of substituting inorganic trace minerals (ITM) with advanced chelate technology-based TM (ACTM) in broiler chicken feed on productive performance, metabolic profile, humoral immunity, antioxidant status, and modulation of NF-kB and Nrf2 signaling pathways in mixed Eimeria species exposure. The study involved 480 newly hatched male broiler chickens, which were divided into 5 treatment groups, each with 6 replicate cages and 16 chickens per replicate. The experimental treatments included an uninfected negative control group fed a basal diet with recommended inorganic TM levels (NC), an infected positive control group fed the same diet (PC), a PC group supplemented with salinomycin (SAL), and two PC groups in which the basal diet was replaced with 50% and 100% ACTM instead of inorganic TM (ACTM50 and ACTM100, respectively). All groups, except for the NC group, were orally challenged with mixed Eimeria species oocysts on day 14. According to the results, the PC group showed lower feed intake, breast yield, low-density lipoprotein-cholesterol concentration, lactobacillus spp. counts, and serum IgG levels, but higher jejunal TGF-β expression versus the NC group. The broilers in the NC, SAL, and ACTM100 groups showed higher body weight gain, carcass yield, and TGF-β expression, but lower serum alkaline phosphatase activity, ileal E. coli count, and jejunal expression levels of IL-1β, IL-6, IFN-γ, Nrf2, and SOD1 compared to the PC group, with the NC group having the highest body weight gain and lowest IL-1β and Nrf2 expression levels. Furthermore, the administration of ACTM100 treatment improved feed efficiency, increased serum iron, zinc, manganese, and copper levels, enhanced total antioxidant capacity and different antioxidant enzyme activities, and reduced malondialdehyde concentration. In conclusion, complete replacement of ITM with ACTM effectively protects broilers from Eimeria infection, with similar positive effects to SAL treatment in terms of productive performance and anti-inflammatory responses and better antioxidant responses and mineral availability.

Animal breeding and feeding tools may close human nutrition gaps

The last century has witnessed many innovations in agriculture and food technologies that have ensured the production of sufficient quantities of good hygienic food. Animal scientists have contributed substantially to efficient breeding and feeding practices by adapting animals for faster growth and improving feed efficiency and utilization. Breeding goals and feeding recommendations have been proposed with a primary focus on profitability to promote significant changes in the macronutrient content, i.e., animal body protein and fat reduction. However, improving the nutritional quality of meat was not included in the profit assessment. Increasing the lean meat fraction is consistent with the goal of public dietary guidelines for human nutrition proposed in 1980, emphasizing the importance of reducing the consumption of animal fat, particularly saturated fat. The application of breeding and feeding tools to modify and improve the fatty acid composition has been partly implemented in pigs and broiler chickens to supplement the dietary recommendations for humans. The health benefits of lean “red meat” have been questioned in recent years, with dietary guidelines and upper limits being introduced for human intake. Animal breeding indirectly reduces the total and heme iron (the redness generator) content in meat, due to covariation with priority breeding goals. Two micronutrients play important roles in the human diet and are derived largely from meat (selenium) and milk (iodine) if the amount provided and absorbed is sufficient and predictable. The iodine content can be highly dependent on the use of novel (more sustainable) feeds. The micronutrients discussed in this study (Fe, Se, I, and vitamin D) highlight opportunities for the utilization of breeding and feeding knowledge to adjust their levels to procure meat with a high nutrient density. The gaps in micronutrient levels in humans must be addressed by navigating within approved animal feeding levels. Animal scientists must recognize the nutritional impact of breeding and feeding and advertise them. In addition, human nutritionists must acknowledge the existing and potential changes in animal production to meet the dietary guidelines. Sustainable food production within the “One Health” concept can only be achieved through cooperation.

Short-term starvation and refeeding in the greater amberjack (Seriola dumerili, Risso 1810): New insights on physiological and metabolic traits

The greater amberjack (Seriola dumerili) is a fish species with high commercial value and excellent growth rates, which has led to increasing interest in the aquaculture sector to optimize and expand its production. To gain a deeper insight into its physiological aspects, the present study aimed to evaluate the metabolic responses of S. dumerili juveniles after a short period of starvation and subsequent refeeding. For this purpose, the fish were fed ad libitum twice a day for four weeks and were then subjected to a starvation challenge followed by a refeeding period of seven days each. After one week of starvation, the fish showed weight loss but were able to adapt their metabolism by maintaining carbohydrate levels and using lipids and proteins as the main energy sources. All this was supported by decreased glycogenolytic potential during starvation, indicated by lower GP activity, and an increase in gluconeogenic pathway, as evidenced by the observed activity of FBP, LDH, and transaminases (ALT and AST). Moreover, the refeeding period stimulated growth processes by activating metabolic pathways, resulting in higher feed efficiency rates. Correspondingly, the highest plasma cortisol levels were observed during the refeeding period, stimulating anticipatory activity after starvation and contributing to metabolic recovery. In conclusion, S. dumerili can efficiently regulate its internal environment during a short period of starvation, improving feed efficiency and growth parameters after refeeding and rapidly restoring the initial metabolic state. These results could represent promising insights to enhance the feeding program for this species.

Feeding of bakery products as replacement of cereal grains alter fecal microbiome and improve feed efficiency in fattening pigs

The re-integration of former foodstuffs, such as bakery products (BP), into pig feed reduces the feed-food competition and increases the sustainability of pig production. Nevertheless, there are concerns about the altered fatty acid profile in BP compared to standard diets and their effects on meat quality and the intestinal microbiome. The present study investigated the effects of replacing 30% cereal grains with BP in the diet on performance, microbiome composition and metabolites in feces of fattening pigs, economic aspects and meat quality characteristics. A total of 132 pigs (Large White × Piétrain; 11 weeks of age) were fed two diets containing 0 or 30% BP until reaching slaughter weight in three replicate batches. Fecal samples were collected for 16S rRNA amplicon sequencing after 6 weeks, whereas body fat samples were collected after 9 weeks on the diet. The results showed that BP can replace cereals in pig diets by up to 30% without impairing animal performance, while improving feed efficiency and reducing feed costs by 9% compared to the control. Additionally, pigs fed the BP diet had a 50%-higher n-3 fatty acid content in the neck and abdominal fat compared to the control. The improved feed efficiency in BP-fed pigs may be related to positive effects on the fecal microbiome, such as a higher alpha diversity and a reduction of fungi and yeasts. Our study provides valuable insights into the benefits of including BP in diets of fattening pigs, which should be investigated in future studies on other BP types.

Investigating the impact of biochar on methane gas emissions and its effect on enteric fermentation

This study aims to evaluate the impact of biochar on methane gas emissions and to investigate its effect on enteric fermentation. Methane gas emissions from Naeemi ewes' ruminants were measured, with animals divided into two groups, each containing 14 ewes. The treatment group was fed a combination of biochar and a basal ration, while the control group received the basal ration alone. The results demonstrate that the initial gas emission for both animal groups at day 0 was 1082 ppm, and the inclusion of biochar in the diet significantly (P < 0.05) reduced CH4 gas emissions by 65.58 %–78.39%. Furthermore, feeding Naeemi sheep with biochar and the basal ration led to a significant (P < 0.05) increase in body weight (63.66 kg) and growth rate (length: 79.3 cm, waist: 81.75 cm, and height: 99.76 cm) compared to the control group. Additionally, it raised the average body condition score (BCS) to 3.56, in contrast to the control group's score of 2.83, primarily due to the positive impact of biochar on fat gain. The study revealed that biochar enhances nutrient utilization, improves feed efficiency, and significantly reduces methane gas emissions in livestock. When incorporated into the sheep's diet, biochar can modify digestive processes and promote better nutrient absorption.

Association of genomically enhanced residual feed intake with performance, feed efficiency, feeding behavior, gas flux, and nutrient digestibility in growing Holstein heifers.

Residual feed intake (RFI), a metric of feed efficiency, is moderately heritable and independent of 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 study was to examine the differences in performance, feed efficiency, feeding behavior, gas flux, and nutrient digestibility in Holstein heifers with divergent genomically enhanced breeding values for RFI (RFIg). Holstein heifers (n = 55; BW = 352 ± 64kg) with low (n = 29) or high (n = 26) RFIg were selected from a contemporary group of 453 commercial Holstein heifers. Heifers were rotated between 1 of 2 pens, each equipped with four electronic feed bunks and one pen with a GreenFeed gaseous exchange monitoring (GEM) system. Individual dry matter intake (DMI) and feeding behavior data were collected for 84-d. Body weight (BW) was measured weekly and spot fecal samples collected at weighing. Phenotypic RFI (RFIp) was calculated as the residual from regression of DMI on average daily gain (ADG) and mid-test metabolic BW (BW0.75). A mixed model including the fixed effect of RFIg classification and random effect of group was used to evaluate the effect of RFIg classification on response variables. There were no differences (P > 0.05) in BW and ADG for heifers with divergent RFIg; however, low RFIg heifers consumed 7.5% less (P < 0.05) feed per day. Consequently, low RFIg heifers exhibited a more favorable (P < 0.05) RFIp (-0.196 vs 0.222kg/d, respectively). Low RFIg heifers had 8.7% fewer (P < 0.05) bunk visit (BV) events per day and tended to have a 11.2% slower (P < 0.10) eating rate. Low RFIg heifers had 7.7% lower (P < 0.05) methane (CH4) emissions (g/d), 6.1% lower (P ≤ 0.05) carbon dioxide (CO2) production (g/d), and 5.6% lower (P ≤ 0.05) heat production (Mcal/d) than high RFIg heifers. However, CH4 yield and CO2 yield (g/kg DMI), and heat production per unit DMI (Mcal/kg DMI) did not differ (P > 0.05) between heifers with divergent RFIg. Dry matter and nutrient digestibility did not differ (P > 0.05) between heifers with divergent RFIg. Overall, heifers selected to be more feed efficient exhibited more favorable energy efficiencies and feed efficiency phenotypes. Results suggest that selection based on RFIg provides opportunities to select cattle with favorable feed efficiency phenotypes to increase the economic and environmental sustainability of the cattle industry.

Performance, Meat Quality and Gene Expression of Grazing Lambs Supplemented with Macadamia Oil and Vitamin E

Macadamia oil has high concentrations of oleic and palmitoleic fatty acids, which can increase tissue sensitivity to insulin, improving glucose absorption efficiency, and reducing lipogenesis through gene modulation. The objective of this study was to evaluate the effects of macadamia oil associated with vitamin E supplementation on performance, blood parameters, meat quality and sensory characteristics, meat fatty acid profile, and expression of genes associated with lipid metabolism in grazing lambs. The experimental treatments were control diet (Control), Control + 0.1% of body weight of macadamia oil (MO), MO + 745 IU of vitamin E/dry matter (MOVE). Macadamia oil improved feed efficiency, reflecting a lower dry matter intake, as the average daily weight gain did not differ from Control. Meat quality parameters were not affected by macadamia oil or vitamin E supplementation. Supplementation with macadamia oil improved meat appearance, flavor, and overall liking. Supplementation with macadamia oil provided a higher proportion of C18:3 n3 and a lower proportion of CLA. The expression of SREBP-1c, PPAR-α, SCD1, and ELOVL6 genes were not modified with the supplementation of macadamia oil and vitamin E. In conclusion, supplementation with macadamia oil improves feed efficiency and meat quality; and the inclusion of 745 IU of vitamin E/kg of dry matter for grazing lambs reduces 36% of lipid oxidation of the meat.

A New Strain of Saccharomyces cerevisiae in Diets of Lactating Holstein Cows Improved Feed Efficiency and Lactation Performance

Abstract This study compared the effects of feeding a new strain of Saccharomyces cerevisiae HSA2020 with a commercial strain on in vitro rumen fermentation and production performance of dairy cows. Permeate was used as a substrate for the laboratory production of the new strain of S. cerevisiae after the hydrolysis by β-galactosidase (5000 µ/mL at 37°C). Two experiments were conducted: in Experiment 1, the effects of three levels (1, 2 and 3 g/kg dry matter) of S. cerevisiae on in vitro ruminal fermentation kinetics were evaluated. In Experiment 2, for 60 days, sixty multiparous Holstein cows (639±24.8 kg BW, 3±1 parity, 7±1 days in milk, with a previous milk production of 23±2.0 kg/d) during the previous lactation, were randomly assigned to 3 treatments in a completely randomized design. Cows were fed without any additives (control treatment) or supplemented with 2 g/kg feed daily of laboratory produced (PY) or commercial (CY) S. cerevisiae. In Experiment 1, inclusion of PY and CY increased (P&lt;0.05) gas production, propionate, and nutrient disappearance, while decreased (P&lt;0.05) methane production and protozoal count. Moreover, in Experiment 2, PY followed by CY increased (P&lt;0.01) nutrient digestibility, and serum concentrations of total protein, albumin, and glucose (P&lt;0.05). Higher daily milk yield, and milk energy output were observed with PY and CY without affecting concentrations of milk components or milk fatty acid profile. Compared to control, increased feed efficiency was observed with PY and CY. Compared to PY, CY increased serum concentrations of urea-N and decreased triglycerides, while PY decreased serum aspartate transaminase and increased concentration of conjugated linoleic acids in milk. In early lactating cow diets, both strains of S. cerevisiae improved production performance at 2 g/kg, and minimal differences between strains were found.

Antioxidant and Immunological Properties of Dracocephalum moldavica Extract in Penaeus vannamei

Objectives: The effects of different concentrations of Dracocephalum moldavica extract (DME) supplement on growth, survival, antioxidants, some biochemical parameters and innate immunity of White leg shrimp (Penaeus vannamei) juveniles investigated. Methods: For 56 days, shrimp (4.5-5 g) received diets that were enhanced with 0 (control), 50, 100, 200 mg DME/kg feed to attain apparent satiety. Results: The results revealed that feeding shrimp with DME significantly improved Feed efficiency and Feed conversion ratio with an optimum level of 200 mg/kg diet. Dietary DME supplementation had no significant effects on their carcass composition. Total albumin and protein higher (P &gt; 0.05) in DME-fed particularly at 200 mg/kg treatment On the other hand, shrimp fed 200 mg DME/kg feed experienced significant decreases in aspartate and alanine aminotransferase levels. As dietary extract levels increased, there was a significant (P &lt; 0.05) increase in SOD and CAT activities, as well as LYZ and PO levels, so that treatments with 100 and 200 mg DME/kg feed had the highest values, and Significant (P &lt; 0.05) reductions in MDA and NO levels were observed at high dietary extract levels of 100 and 200 mg DME/kg. Conclusion: P. vannamei's growth, antioxidant capacity and innate immunity were boosted by diets that contained 200 mg DME/kg feed.

Genomic selection for individual feed efficiency in the European seabass: Response to selection on efficiency, commercial traits and sex

Feed efficiency is a key factor in the sustainability of fish farming. Improving feed efficiency not only results in cost savings, but also helps to reduce the environmental footprint associated with feed production and to mitigate competition for feed resources. However, improving feed efficiency through genetic selection poses challenges, mainly due to the difficulty of accurately estimating it in a large population, especially under conventional rearing conditions. In a previous study, a methodology was developed to estimate the individual feed efficiency of sea bass in separate tanks under controlled feeding regimes during the juvenile phase. This approach allowed precise measurement of growth, feed intake and individual feed conversion ratio (iFCR) of each fish. Daily growth rate (iDGC) was found to be highly heritable (h2 = 0.75), and a reliable predictor of iFCR under restricted feeding conditions. In the present study, we aim to demonstrate the response to selection on feed efficiency, commercial traits and sex.From a cohort of 399 sea bass with known iDGC and genotyped for 1110 SNP markers, we selected 27 future efficient parents (Eff+), 35 intermediate parents (Eff0) and 29 inefficient parents (Eff-) by genomic selection (GBLUP). Three years later, 3 groups of offspring were produced from 9 Eff + parents, 13 Eff0 parents and 19 Eff- parents. Performances in individual aquaria (iDGC, iFCR) were assessed for 259 of them, as well as group feed efficiency (gFCR) from 142 g. At 240 g, the fish were slaughtered to assess processing traits.The results showed that the Eff + group had superior efficiency (iFCR and iDGC) and better adaptability to tank conditions compared to the other groups. In the group evaluation phase, significant differences in feed efficiency were observed between Eff- (gFCR = 1.83) and Eff + (gFCR = 1.61) (p < 0.001), with Eff0 being intermediate. In addition, Eff + fish were larger (266 g, 27.4 cm) and leaner with lower Fulton K values compared to Eff0 (234 g, 26.1 cm) and Eff- (223 g, 25.5 cm). Although there were no differences in fillet yield, Eff + had a slightly higher viscerosomatic index. There was also a higher proportion of females in the Eff- (57.1 %) and Eff0 (51.6 %) groups compared to Eff + (43.9 %).In conclusion, selection for feed efficiency in individual tanks is an effective strategy for improving the performance of sea bass, resulting in significant improvements with a marked effect on growth rates. Despite a slight increase in the viscerosomatic index, fillet yield was not significantly affected.

Effects of Feeding Frequency on Liver Transcriptome: Unveiling Appetite-Regulating Peptides in Mexican Pike Silverside (Chirostoma estor)

The Mexican pike silverside (Chirostoma estor) is a zooplanktivorous, agastric short-intestined species, and it has been found that increased-frequency feeding (twelve feedings a day) improved feed efficiency and promoted growth by 70%. This work determined the effect of different juvenile feeding frequencies upon the C. estor liver transcriptome. The level of the expression of appetite-regulating peptides was analyzed in silico to understand the mechanisms involved in appetite control in this species. Differential expression analysis showed that up-regulated genes between treatments were related to metabolism, digestive processes, immune system response, apoptosis, growth, and oxidative stress. This information explains the better performance of pike silverside fed 12 times daily. Appetite regulatory peptides were identified for the first time in the liver of C. estor in response to high feeding frequencies, contributing to the general knowledge of the roles of each family of neuropeptides in this agastric, short-intestined fish. The information presented here emphasizes the need to explore further the complex physiological processes involved in appetite regulation in C. estor. Additionally, it will serve as a basis for more specific targeted studies of appetite control to elucidate the mechanisms behind this process.

Polymorphisms of PRKAA1 and FABP4 genes and their association with feed efficiency in Hu sheep

Feed efficiency (FE) is an important economic trait in the sheep industry, influenced by biological processes such as digestion and metabolism. PRKAA1 gene participates in the synthesis and oxidation of fatty acids; the FABP4 gene is closely associated with intracellular fatty acid regulation. In this study, we use Sanger sequencing, KASPar genotyping, and qRT-PCR to investigate the association between variations in PRKAA1 and FABP4 genes and feed efficiency in Hu sheep, the expression patterns of PRKAA1 and FABP4 genes in different tissues, as well as the differences in expression of different genotypes in tail fat. The association analysis results indicated that PRKAA1 gene g.35431965 C > T locus and FABP4 gene g.62829807 C > T locus were significantly associated with the feed conversion ratio (FCR) of Hu sheep aged 80–180 days, with the dominant genotypes being CC and CC, respectively. Simultaneously, there existed notable disparities among various genotype combinations. The qRT-PCR results showed PRKAA1 and FABP4 genes were widely expressed in ten tissues, of which the PRKAA1 gene was lower expression level in rumen and lung, FABP4 gene was significantly highest expression in the tail fat than the other tissues; the expression of two different genotypes in tail fat also exhibits significant differences (P ≤ 0.05). Therefore, these findings suggested that the variation of PRKAA1 and FABP4 genes might be used as novel genetic marker for improving feed efficiency in sheep.

Insight into the Gut-Brain Axis and the Productive Performance and Egg Quality Response to Kudzu Leaf Flavonoid Supplementation in Late-Laying Hens.

(1) Background: Improving feed efficiency and the vitality of the reproductive system in the late stage of the egg-laying period is of great significance for prolonging the egg-laying cycle and improving egg quality. In the present study, a new flavonoid, which was extracted from kudzu leaf, was chosen to investigate its effects on the productive performance and egg quality of late-laying hens. (2) Methods: A total of 360 500-day-old Hy-Line Brown layer hens were randomly divided into a control treatment group (no KLF supplementation), and groups that received 0.2%, 0.4%, 0.6%, 0.8%, and 1.0% KLF supplement treatments. Each treatment contained 6 replicates, with 10 hens in each replicate. Productive performance metrics, including the daily egg production, egg weight, the number of deformed eggs, egg quality, egg density, egg shape index, eggshell strength, yolk color, and the Haugh unit, were meticulously recorded for each replicate. Furthermore, microbial communities and hypothalamus gene expressions were investigated based on the results of the productive performance and egg quality. (3) Results: KLF supplementation significantly decreased the deformity rate while significantly increasing the eggshell strength in the finishing phase afterward (p < 0.05). Specifically, hens supplemented with 0.6% KLF possessed the lowest deformed egg rate. KLF supplementation significantly increased the relative abundances of Bifidobacterium sp., Blautia sp., Lactococcus sp., and Lactobacillus sp., while significantly decreasing Parasutterella sp. and Escherichia-Shigella sp. (p < 0.05). Furthermore, the interactive analysis showed the hypothalamus gene expression mainly interacted with probiotics, such as Bifidobacterium sp. and Lactobacillus sp., through ribosome biogenesis, nucleocytoplasmic transport, and cAMP signaling pathways. (4) Conclusions: The findings of the present study indicate that KLF supplementation significantly proliferated probiotics, such as Bifidobacterium and Lactobacillus, which may have further interacted with hypothalamus genes, thus decreasing the deformity rate while increasing eggshell strength in the finishing phase.

In ovo feeding of l-arginine and selenium nanoparticles influences post-hatch growth, muscle development, antioxidant status, and meat quality in slow-growing chickens.

This study investigated the effects of in ovo feeding (IOF) of l-arginine (L-Arg), selenium nanoparticles (SeNP), and a combination of L-Arg and SeNP on the hatchability, post-hatch growth, muscle development, antioxidant status, and meat quality of slow-growing chickens. On day 18 of incubation, a total of 960 fertilized eggs with similar weights were randomly assigned to 4 treatment groups with 4 replicates of 60 eggs each: (1) non-injected control group (Control), (2) injected with 1% of L-Arg (IOF_L-Arg), (3) injected with 0.3 µg/egg of SeNP (IOF_SeNP), and (4), injected with 1% of L-Arg and 0.3 µg/egg of SeNP (IOF_L-Arg + SeNP). A completely randomized design was used. After hatching, 640 mixed-sex chicks were allocated to 4 treatment groups and split into 4 replicate pens (40 birds per pen). All groups of chicks were fed with commercial feed ad libitum until they reached 63 d of age and were subsequently weighed and slaughtered. The results of the present study showed that hatchability was similar among treatments. Final BW or breast muscle yield was not affected (P > 0.05) by IOF treatment. Chickens treated with IOF_L-Arg + SeNP exhibited decreased feed conversion ratio, drip loss, and increased protein content in breast meat (P < 0.05). The IOF_L-Arg + SeNP group exhibited a higher density of breast muscle fibers than the control group (P < 0.05). Overall, in ovo feeding of L-Arg combined with SeNP resulted in improved feed efficiency and enhanced antioxidant capacity at hatch without any adverse effects on chicken hatchability, health, or subsequent growth. Furthermore, meat from chickens in the IOF_L-Arg + SeNP group exhibited a preferable texture with a higher protein content.

Does Pelleted Starter Feed Restriction and Provision of Total Mixed Ration Ad Libitum during Weaning Influence the Behavior of Dairy Calves?

Currently, in dairy farming, there is growing concern for the welfare of calves during the critical period between the separation from their dams and weaning. During weaning, rationed feeding is a practice used to improve feed efficiency and control the calves’ growth, but it could also have negative consequences associated with hunger and feed restriction behavior. One such consequence could be the performance by calves of stereotyped behaviors indicative of poor welfare, such as non-nutritive oral behaviors. We hypothesized that making a Total Mixed Ration (TMR) available to calves, in addition to the standard pelleted starter diet, thanks to its structural and nutritional characteristics, could help to focus the oral behavior of the subjects towards nutritional activities and therefore limit the development of stereotyped behaviors, even when the amount of starter is restricted. To test this hypothesis, 30 female Holstein calves (equipped with an accelerometer based on an ear tag), were randomly assigned to one of three treatments: a control diet (CTR) with an ad libitum calf starter but without TMR; Treatment 1 (TRT1) with both ad libitum calf starter and ad libitum TMR; Treatment 2 (TRT2) with ad libitum TMR and a restricted amount of a calf starter (50% of the intake starter of the control group day by day). All animals were kept in individual cages equipped with a slow-flow teat bucket apparatus for milk feeding and with access to separated buckets (one for drinking water, one for the starter, and one for the TMR) placed on the outside of the front gate of each cage. Sucking behavior, as well as resting, ruminating and activity behavior, was recorded individually from 7 days of life to weaning (63 d of age) by an automated monitoring system based on ear-tag accelerometers (SCR eSense, Allflex, Irving, TX, USA). The results showed that in the CTR group, there was a greater sucking activity compared to the TRT1 group (26.25 min/head/day vs. 16.83 min/head/day, p = 0.0181), while the TRT2 group showed intermediate values (20.41 min/head/day). We hypothesized that this increased sucking activity may be explained by the oral activity directed at sucking the Milk Bar tube observed only in CTR calves after complete consumption of available milk and could indicate a higher stress level than in the TRT1 group. The time spent resting was significantly lower for the CTR group compared to the TRT1 group (9.20 h/day vs. 11.15 h/day, p = 0.0049) while the TRT2 group was in an intermediate situation (10.65 h/day). Furthermore, the increase in time dedicated to rest observed in TRT1, in light of the good vitality of the calves shown by the daily patterns of resting behavior and daily activity, also seems to suggest an improvement in welfare conditions compared to calves receiving pelleted starter alone. Based on these results, we can deduce that providing TMR ad libitum in the diet of weaning calves could be an effective strategy to improve calf welfare due to the reduction in stereotyped oral activity. However, further studies are needed to establish threshold values useful for distinguishing physiological from pathological resting times in weaning calves raised in individual cages.