Search

Background: The trace element lithium (Li) is known for its therapeutic mood-stabilizing application in humans, but also for its various bioactivities, which have been uncovered in model organisms. According to the literature, Li may interfere with the homeostasis of other minerals in mammals, namely sodium, calcium and magnesium. In addition, Li was found to influence the composition and diversity of the intestinal microbiota in vertebrates, an observation that may be related to the many bioactivities of Li., Methods: Based on these previous findings, we employed the model organism Drosophila melanogaster to decipher whether Li exhibits similar bioactivities in invertebrates. First, we examined the influence of increasing dietary Li supply (0 -100 mM LiCl) on the status of Li and ten other minerals via Inductively coupled plasma - mass spectrometry (ICP-MS) in heads and remaining body parts of the three wildtype strains w 1118 , Oregon-R-C and Canton-S. In addition, we investigated the potential impact of Li feeding (0, 0.1, 1 mM LiCl) on the total bacterial load, α- and β-diversity via real-time quantitative polymerase chain reaction (RT q-PCR) and 16S rDNA sequencing in the intestines of female w 1118 ., Results: Our observations revealed that Li accumulates linearly in both sexes and all body parts of the three Drosophila strains as the dietary Li supply increases. While the status of most elements remained unchanged, the sodium levels of the fly also correlated positively with the Li content of the diet. The intestinal microbiota, however, remained largely unaffected by Li feeding in terms of both, bacterial load and diversity., Conclusion: These findings support the hypothesis that elevating the Li supply affects sodium homeostasis in Drosophila, a finding coherent with observations in mammals. Furthermore, our data opposes a possible involvement of the bacterial intestinal colonization in the bioactivity of Li in Drosophila., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests. Gerald Rimbach reports financial support was provided by German Research Foundation. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier GmbH.. All rights reserved.)

The filamentous fungus Aspergillus oryzae has a long tradition in East Asian food processing. It is therefore not surprising that in recent years fermentation products of A. oryzae have attracted attention in the emerging field of postbiotics. This review aims to provide a comprehensive summary of the potential postbiotic effects of fermentation products from A. oryzae , by discussing possible mechanisms of action against the background of the molecular composition determined so far. In particular, cell wall constituents, enzymes, extracellular polymeric substances, and various metabolites found in A. oryzae fermentation preparations are described in detail. With reference to the generally assumed key targets of postbiotics, their putative beneficial bioactivities in modulating the microbiota, improving epithelial barrier function, influencing immune responses, metabolic reactions and signaling through the nervous system are assessed. Drawing on existing literature and case studies, we highlight A. oryzae as a promising source of postbiotics, particularly in the context of animal health and nutrition. Challenges and opportunities in quality control are also addressed, with a focus on the necessity for standardized methods to fully harness the potential of fungal-based postbiotics. Overall, this article sheds light on the emerging field of A. oryzae -derived postbiotics and emphasizes the need for further research to fully realize their therapeutic potential., Competing Interests: The authors declare that the Institute of Human Nutrition and Food Science (including YS, GR, II, and KL) received funding from BioZyme Incorporated. YS and II received consulting fees from BioZyme Incorporated. GV is a board member of the ISAPP., (Copyright © 2024 Seidler, Rimbach, Lüersen, Vinderola and Ipharraguerre.)

Background & Aims: We aimed to investigate the relative efficacy of feeding different bile acids in preventing PNALD in neonatal pigs., Methods: Newborn pigs given total parenteral nutrition (TPN) combined with minimal enteral feeding of chenodeoxycholic acid (CDCA), or increasing doses of obeticholic acid (OCA) for 19 days., Results: Enteral OCA (5 and 15 mg/kg), but not CDCA (30 mg/kg) reduced blood cholestasis markers compared to TPN controls and increased bile acids in the gallbladder and intestine. Major bile acids in the liver and distal intestine were CDCA, HCA, HDCA and OCA, and their relative proportions were increased by the type of bile acid (CDCA or OCA) given enterally. High doses of OCA increased the total NR1H4-agonistic bile acid profile in the liver and intestine above 50% total bile acids. Both CDCA and OCA treatments suppressed hepatic cyp7a1 expression, but only OCA increased hepatobiliary transporters, ABCB11, ABCC$ and ABCB1. Plasma phytosterol levels were reduced and biliary levels were increased by CDCA and OCA and hepatic sterol transporters, abcg5/8, expression were increased by OCA. Both CDCA and OCA increased plasma FGF19 and OCA increased intestinal FGF19, FABP6, and SLC51A. Both CDCA and OCA increased intestinal mucosal growth, whereas CDCA increased the plasma GLP-2, GLP-1 and GIP., Conclusions: Enteral OCA prevented cholestasis and phytosterolemia by increased hepatic bile acid and sterol transport via induction of hepatobiliary transporter FXR target genes and not by suppression of bile acid synthesis genes. We also showed an intestinal trophic action of OCA that demonstrates a dual clinical benefit of FXR agonism in the prevention of PNALD in piglets., Competing Interests: Conflict of interest The obeticholic acid used in the study was provided as a gift from Intercept Pharmaceuticals, Inc.

Plant extracts are increasingly recognized for their potential in modulating (postprandial) blood glucose levels. In this context, root extracts are of particular interest due to their high concentrations and often unique spectrum of plant bioactives. To identify new plant species with potential glucose-lowering activity, simple and robust methodologies are often required. For this narrative review, literature was sourced from scientific databases (primarily PubMed) in the period from June 2022 to January 2024. The regulatory targets of glucose homeostasis that could be modulated by bioactive plant compounds were used as search terms, either alone or in combination with the keyword "root extract". As a result, we present a comprehensive methodological toolbox for studying the glucose homeostasis modulating properties of plant extracts and its constituents. The described assays encompass in-vitro investigations involving enzyme inhibition (α-amylase, α-glucosidase, dipeptidyl peptidase 4), assessment of sodium-dependent glucose transporter 1 activity, and evaluation of glucose transporter 4 translocation. Furthermore, we describe a patch-clamp technique to assess the impact of extracts on K ATP channels. While validating in-vitro findings in living organisms is imperative, we introduce two screenable in-vivo models (the hen's egg test and Drosophila melanogaster ). Given that evaluation of the bioactivity of plant extracts in rodents and humans represents the current gold standard, we include approaches addressing this aspect. In summary, this review offers a systematic guide for screening plant extracts regarding their influence on key regulatory elements of glucose homeostasis, culminating in the assessment of their potential efficacy in-vivo . Moreover, application of the presented toolbox might contribute to further close the knowledge gap on the precise mechanisms of action of plant-derived compounds., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Bauer, Rimbach, Cordeiro, Bosy-Westphal, Weghuber, Ipharraguerre and Lüersen.)

Non-protein nitrogen ( NPN ) supplements improve animal performance in backgrounding diets. However, there is scarce information regarding the effect of different NPN sources and combinations on ruminal fermentation profile. The current study aimed to evaluate the effect of different NPN sources and their combinations on in vitro fermentation, microbial N synthesis, and methane (CH 4 ) production in a backgrounding diet. Incubations were conducted on three separate days for 24 h using corn silage and cotton gin byproduct (70% and 30% of DM, respectively) as substrate. Treatments were control (without NPN), urea, and five different proportions of urea-biuret and nitrate (100:0, 75:25, 50:50, 25:75, and 0:100). Each treatment, except control, was formulated to be isonitrogenous and equivalent to 1% urea inclusion. Ruminal fluid was collected from two ruminally cannulated Angus crossbred steers fed ad libitum corn silage and cotton gin byproduct plus 100 g of a urea-biuret-nitrate mixture. The concentration of volatile fatty acids ( VFAs ) and ammonia nitrogen ( NH 3 -N ) were determined at 12 and 24 h of incubation. Final pH, in vitro dry and organic matter digestibility, total gas production, and concentration of CH 4 were determined at 24 h. The supplementation of NPN increased ( P  < 0.05) the concentration of NH 3 -N at 12 and 24 h. Although NPN supplementation increased ( P  < 0.05) the concentration of total VFA and acetate at 12 h, treatments did not differ ( P  > 0.05) at 24 h. Supplementation of NPN increased ( P  < 0.05) the proportion of acetate at 12 and 24 h but tended to reduce ( P  = 0.054) the proportion of propionate only at 12 h. Digestibility and pH were not different ( P  > 0.05) among treatments. Increasing nitrates in the NPN supplement increased ( P  < 0.05) the proportion of acetate and reduced ( P  < 0.05) the proportion of butyrate at 12 and 24 h. The supplementation of NPN increased ( P  < 0.05) microbial N synthesis. Furthermore, increasing nitrate proportion in the NPN supplement increased ( P  < 0.05) the microbial N synthesis and efficiency of N use. Supplementation of NPN did not modify ( P  > 0.05) total gas or CH 4 production. However, increasing nitrate proportion in the NPN supplement linearly reduced ( P  < 0.05) CH 4 production. Supplementation of NPN increased NH 3 -N concentration and microbial N while increasing the inclusion of nitrate decreased the production of CH 4 and increased the microbial N synthesis in a corn silage-based substrate under in vitro conditions., Competing Interests: Isabel Ruiz-Ascacibar works in the R&D department of YARA Industrial Solutions. The other authors declare no real or perceived conflicts of interest., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science.)

Background: Ahiflower oil from the seeds of Buglossoides arvensis is rich in α-linolenic acid (ALA) and stearidonic acid (SDA). ALA and SDA are potential precursor fatty acids for the endogenous synthesis of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are n3-long chain polyunsaturated fatty acids (n3-LC-PUFAS), in humans. Since taurine, an amino sulfonic acid, is often associated with tissues rich in n3-LC-PUFAS (e.g., in fatty fish, human retina), taurine may play a role in EPA- and DHA-metabolism., Objective: To examine the capacity of the plant-derived precursor fatty acids (ALA and SDA) and of the potential fatty acid metabolism modulator taurine to increase n3-LC-PUFAS and their respective oxylipins in human plasma and cultivated hepatocytes (HepG2 cells)., Methods: In a monocentric, randomized crossover study 29 healthy male volunteers received three sequential interventions, namely ahiflower oil (9 g/day), taurine (1.5 g/day) and ahiflower oil (9 g/day) + taurine (1.5 g/day) for 20 days. In addition, cultivated HepG2 cells were treated with isolated fatty acids ALA, SDA, EPA, DHA as well as taurine alone or together with SDA., Results: Oral ahiflower oil intake significantly improved plasma EPA levels (0.2 vs. 0.6% of total fatty acid methyl esters (FAMES)) in humans, whereas DHA levels were unaffected by treatments. EPA-levels in SDA-treated HepG2 cells were 65% higher (5.1 vs. 3.0% of total FAMES) than those in ALA-treated cells. Taurine did not affect fatty acid profiles in human plasma in vivo or in HepG2 cells in vitro . SDA-rich ahiflower oil and isolated SDA led to an increase in EPA-derived oxylipins in humans and in HepG2 cells, respectively., Conclusion: The consumption of ahiflower oil improves the circulating levels of EPA and EPA-derived oxylipins in humans. In cultivated hepatocytes, EPA and EPA-derived oxylipins are more effectively increased by SDA than ALA., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Seidel, Eberhardt, Wiebel, Luersen, Ipharraguerre, Haegele, Winterhalter, Bosy-Westphal, Schebb and Rimbach.)

This graduate student literature review provides an examination of the ontological adaptations of the calf's immune system and how the intestinal microbiota influences calf immune function in health and disease. Within dairy rearing systems, various nutritional and management factors have emerged as critical determinants of development influencing multiple physiological axes in the calf. Furthermore, we discuss how multiple pre- and postnatal maternal factors influence the trajectory of immune development in favor of establishing regulatory networks to successfully cope with the new environment, while providing early immune protection via immune passive transfer from colostrum. Additionally, our review provides insights into the current understanding of how the intestinal microbiota contributes to the development of the intestinal and systemic immune system in calves. Lastly, we address potential concerns related to the use of prophylactic antimicrobials and waste milk, specifically examining their adverse effects on intestinal health and metabolic function. By examining these factors, we aim to better understand the intricate relationship between current management practices and their long-term effect on animal health., (The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Recent studies indicate that heat stress pathophysiology is associated with intestinal barrier dysfunction, local and systemic inflammation, and gut dysbiosis. However, inconclusive results and a poor description of tissue-specific changes must be addressed to identify potential intervention targets against heat stress illness in growing calves. Therefore, the objective of this study was to evaluate components of the intestinal barrier, pro- and anti-inflammatory signals, and microbiota community composition in Holstein bull calves exposed to heat stress. Animals (mean age = 12 wk old; mean body weight = 122 kg) penned individually in temperature-controlled rooms were assigned to (1) thermoneutral conditions (constant room temperature at 19.5°C) and restricted offer of feed (TNR, n = 8), or (2) heat stress conditions (cycles of room temperatures ranging from 20 to 37.8°C) along with ad libitum offer of feed (HS, n = 8) for 7 d. Upon treatment completion, sections of the jejunum, ileum, and colon were collected and snap-frozen immediately to evaluate gene and protein expression, cytokine concentrations, and myeloperoxidase activity. Digesta aliquots of the ileum, colon, and rectum were collected to assess bacterial communities. Plasma was harvested on d 2, 5, and 7 to determine cytokine concentrations. Overall, results showed a section-specific effect of HS on intestinal integrity. Jejunal mRNA expression of TJP1 was decreased by 70.9% in HS relative to TNR calves. In agreement, jejunal expression of heat shock transcription factor-1 protein, a known tight junction protein expression regulator, decreased by 48% in HS calves. Jejunal analyses showed that HS decreased concentrations of IL-1α by 36.6% and tended to decrease the concentration of IL-17A. Conversely, HS elicited a 3.5-fold increase in jejunal concentration of anti-inflammatory IL-36 receptor antagonist. Plasma analysis of pro-inflammatory cytokines showed that IL-6 decreased by 51% in HS relative to TNR calves. Heat stress alteration of the large intestine bacterial communities was characterized by increased genus Butyrivibrio&#95;3, a known butyrate-producing organism, and changes in bacteria metabolism of energy and AA. A strong positive correlation between the rectal temperature and pro-inflammatory Eggerthii spp. was detected in HS calves. In conclusion, this work indicates that HS impairs the intestinal barrier function of jejunum. The pro- and anti-inflammatory signal changes may be part of a broader response to restore intestinal homeostasis in jejunum. The changes in large intestine bacterial communities favoring butyrate-producing organisms (e.g., Butyrivibrio spp.) may be part of a successful response to maintain the integrity of the colonic mucosa of HS calves. The alteration of intestinal homeostasis should be the target for heat stress therapies to restore biological functions, and, thus highlights the relevance of this work., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Two experiments were conducted to evaluate the effect of nonprotein nitrogen (NPN) supplementation on in vitro fermentation and animal performance using a backgrounding diet. In experiment 1, incubations were conducted on three separate days (replicates). Treatments were control (CTL, without NPN), urea (U), urea-biuret (UB), and urea-biuret-nitrate (UBN) mixtures. Except for control, treatments were isonitrogenous using 1% U inclusion as a reference. Ruminal fluid was collected from two Angus-crossbred steers fed a backgrounding diet plus 100 g of a UBN mixture for at least 35 d. The concentration of volatile fatty acids (VFA) and ammonia nitrogen (NH3-N), in vitro organic matter digestibility (IVOMD), and total gas and methane (CH4) production were determined at 24 h of incubation. In experiment 2, 72 Angus-crossbred yearling steers (303 ± 29 kg of body weight [BW]) were stratified by BW and randomly allocated in nine pens (eight animals/pen and three pens/treatment). Steers consumed a backgrounding diet formulated to match the diet used in the in vitro fermentation experiment. Treatments were U, UB, and UBN and were isonitrogenous using 1% U inclusion as a reference. Steers were adapted to the NPN supplementation for 17 d. Then, digestibility evaluation was performed after 13 d of full NPN supplementation for 4 d using 36 steers (12 steers/treatment). After that, steer performance was evaluated for 56 d (24 steers/treatment). In experiment 1, NPN supplementation increased the concentration of NH3-N and VFA (P < 0.01) without affecting the IVOMD (P = 0.48), total gas (P = 0.51), and CH4 production (P = 0.57). Additionally, in vitro fermentation parameters did not differ (P > 0.05) among NPN sources. In experiment 2, NPN supplementation did not change dry matter and nutrient intake (P > 0.05). However, UB and UBN showed lower (P < 0.05) nutrient digestibility than U, except for starch (P = 0.20). Dry matter intake (P = 0.28), average daily gain (P = 0.88), and gain:feed (P = 0.63) did not differ among steers receiving NPN mixtures. In conclusion, tested NPN mixtures have the potential to be included in the backgrounding diets without any apparent negative effects on animal performance and warrant further studies to evaluate other variables to fully assess the response of feeding these novel NPN mixtures., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The objective of this study was to evaluate the effects of prophylactic neomycin administration on Holstein bull calves' intestinal microbiota, bile acid (BA) metabolism, and transcript abundance of genes related to BA metabolism. A total of 36 calves were blocked by body weight and assigned to either non-medicated milk replacer (CTL), or neomycin for 14 days (ST) or 28 days (LT) in their milk replacer. At the end of the study, calves were euthanized to collect tissue and digesta samples from the gastrointestinal tract, liver, and adipose tissue for analysis of intestinal microbial diversity, bile acid concentration and profile in various body tissues, and gene expression related to bile acid, lipid, carbohydrate metabolism, and inflammation. Calves that received prophylactic administration of neomycin for 28 d (LT) had reduced species richness (chao1 index), and tended to have reduced phylogenetic diversity in the ileum tissue. The relative abundance of Lactobacillus , and Bifidobacterium in ileum and colon digesta were decreased in LT compared with CTL. Concentrations of primary, secondary, and total BA were increased by ST in ileal tissue. In plasma, ST and LT treatments had lower concentrations of secondary BA. Gene expression of the BA receptor FXR was increased in ileum and liver by LT compared to CTL. The expression of FXR and TGR5 in the liver was increased in the ST group compared with CTL, and in adipose tissue, 5 genes related to triglyceride, gluconeogenesis, and immune activation were differentially expressed between CTL and ST. In conclusion, we provide evidence that prophylactic administration of neomycin leads to aberrant changes in BA concentration and profile in different compartments of the enterohepatic system through a process that possibly entails antimicrobial disruption of key bacterial groups, which persists even after cessation of neomycin administration. Additionally, we uncovered an apparent link between dysregulated BA metabolism and changes in lipid metabolism and immune activation in adipose tissue and liver., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Cangiano, Ipharraguerre, Guan, Buss, Amorin-Hegedus, Chirivi, Contreras and Steele.)

The objective of this study was to determine the effects of Aspergillus oryzae prebiotic (AOP) on nutrient digestibility in growing pigs fed high-fiber diets. Eighteen growing barrows (initial body weight = 50.6 ± 4.9 kg) were surgically equipped with a T-cannula at the distal ileum. Corn and soybean meal-based diets were formulated with fiber from cereal grain byproducts corn (distillers dried grains with solubles, DDGS ), rice (rice bran, RB ), or wheat (wheat middlings, WM ) to meet or exceed all nutrient requirements for 50 to 75 kg growing pigs. Three additional diets were formulated to contain 0.05% AOP supplemented at the expense of corn in the DDGS diet ( DDGS + AOP ), RB diet ( RB + AOP ), and WM diet ( WM + AOP ). All diets contained 0.5% of titanium dioxide as an indigestible marker. Pigs were allotted randomly to a triplicated 6 × 2 Youden square design with six diets and two successive periods. Ileal digesta and fecal samples were collected for 2 d after a 21-d adaptation period, and dry matter (DM ), gross energy ( GE ), crude protein ( CP ), ether extract ( EE ), neutral detergent fiber ( NDF ), and ash were analyzed to calculate apparent ileal digestibility ( AID ) and apparent total tract digestibility ( ATTD ). Standardized ileal digestibility ( SID ) of amino acids ( AA ) was calculated by correcting AID with basal endogenous AA losses from the same set of pigs. Pigs fed the DDGS+AOP diet had greater ( P < 0.05) AID of EE compared with those fed the DDGS diet. However, supplementation of AOP did not ( P > 0.05) affect AID of GE, DM, CP, NDF, ash or SID of AA of any high-fiber diet. Supplementation of 0.05% AOP increased ( P < 0.05) ATTD of DM, GE, CP, NDF, and ash in DDGS, RB, and WM diets. Diet digestible energy was 35 kcal/kg greater ( P < 0.05) in pigs fed AOP supplemented diets compared with those fed diets without AOP. In conclusion, supplementation of AOP increased ATTD of nutrients and energy value in high-fiber diets containing DDGS, RB, or WM., (Published by Oxford University Press for the American Society of Animal Science 2023.)

Eighty-four Angus crossbred heifers (13 ± 1 mo of age, 329.5 ± 61.92 kg of body weight [BW]) were used in a generalized randomized block design with a 2 × 2 factorial arrangement of treatments. The factors evaluated were: 1) diet type (whole plant sorghum silage [SS] vs. byproducts-based [BP]), and 2) feed additive: Aspergillus oryzae prebiotic (AOP; 2 g/d) vs. Negative control (CTL; 0 g/d), resulting in four treatments: sorghum silage-control (SC), sorghum silage-AOP (SA), byproducts-control (BC), and byproducts-AOP (BA). Heifers were stratified by body weight (BW), randomly assigned to treatments (21 heifers per treatment) and housed in 12 pens equipped with two GrowSafe feed bunks each to measure individual dry matter intake (DMI). After a 14-d adaptation, BW was measured every 14 d for 56 d. Chewing activity was monitored through collar-mounted HR-Tags (heat-related tags). Following the performance period, apparent total tract digestibility was measured in 40 heifers, using indigestible neutral detergent fiber as a marker. Heifers fed with the BP diets had greater DMI (2.92% vs. 2.59% of BW, P < 0.01) and average daily gain (ADG; 1.16 vs. 0.68 kg, P ≤ 0.01) than heifers fed with SS diets. Compared with BP-fed animals, heifers consuming the SS diets had 23 more visits/d to the feed bunks (P ≤ 0.01), consumed 53% less dry matter on each visit (P ≤ 0.01), and spent 39% more min chewing/d and 63% more min chewing/kg of DMI (P ≤ 0.01). However, chewing measured in min/kg of neutral detergent fiber intake was not affected by treatment (average 111.3 min/kg of NDF intake). Feeding AOP improved gain:feed (GF) by 15% in BP-fed heifers (0.120 vs. 0.104 kg/kg; P < 0.05). Inclusion of AOP increased organic matter digestibility (OMD) in SS diets (55.88% vs. 49.83%; P < 0.01), whereas it decreased OMD in BP diets (61.67% vs. 65.77%; P < 0.05). In conclusion, ADG and GF of BP-fed heifers was greater than SS-fed heifers, and GF was greater with AOP supplementation in BP-fed heifers. Improvement in GF in BP-fed heifers was likely not related to differences in nutrient digestibility as AOP inclusion did not enhance digestibility in the BP diet. Additionally, the effects of the AOP inclusion appear to be diet-dependent, where the 15% improvement in GF by AOP occurred in heifers fed with the more fermentable diet. Therefore, further research should explore the mechanisms responsible for the observed improvements in growth performance when feeding AOP to BP-fed heifers., (© The Author(s) 2023. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

This study was designed to develop a protocol for repeated intramuscular indomethacin injections to replicate leaky-gut-like symptoms in male Holstein calves to model and study the detrimental effects of leaky gut on gut tissue function and inflammatory response. A generalized randomized block design was used to evaluate how repeated indomethacin intramuscular injections affected the development of leaky gut in 18 male Holstein calves. Animals were enrolled at 3 ± 1 d of life, and after 21 d of adaptation, they were randomly assigned to 1 of 3 treatments consisting of intramuscular saline or indomethacin injections every 12 h for 48 h: (1) control (CTL), saline injection, (2) low intramuscular indomethacin (INDO-L) dosed at 1.2 mg/kg of body weight (BW), and (3) high intramuscular indomethacin (INDO-H) dosed at 2.4 mg/kg of BW. During the challenge, milk intake, starter intake, fecal scores, and rectal temperature were measured daily, and BW was measured at the beginning and at the end of the challenge. Plasma samples were used to measure the recovery of markers of intestinal permeability before and after the challenge by dosing lactulose, d-mannitol, and chromium-EDTA. In addition, several cytokines were measured in plasma during the challenge. Calves were dissected at the end of the challenge to obtain tissue and digesta samples from the gastrointestinal tract and liver. No treatment differences were observed for starter and milk intakes, fecal scores, BW, and rectal temperature. The difference in marker concentrations between pre and post challenges was higher for INDO calves compared with CTL calves in the case of lactulose and chromium-EDTA. In addition, chemokine ligand 2 and 4 and IL-6 were higher for INDO-H calves compared with CTL. Both doses of indomethacin resulted in reductions in villus length and surface area in the distal jejunum and ileum and reductions in crypt depth and width in the colon. We showed that repeated indomethacin injections over a 48-h period induced leaky-gut-like symptoms in a region-specific manner, affecting mainly the distal section of the intestine. This outcome was characterized by histomorphological changes in the distal jejunum, ileum, and colon and by increased gut permeability. Interestingly, changes in liver morphology and immune function also occurred, possibly due to the increased translocation of foreign antigens breaching the epithelial cell wall. The leaky gut challenge model described here could be used to improve understanding of the pathogenesis of intestinal disorders in cattle and provide a reliable alternative for testing feed additives with intestinal health benefits., (© 2022, The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Bioactive compounds present in Olea europaea have shown promising antimicrobial potential as an alternative to conventional coccidiostats. These effects are exerted by triterpenic acids ( TT ) present in the olive plant, namely, oleanolic acid ( OA ), ursolic acid ( UA ), and maslinic acid ( MA ). The objective of this study was to determine the effects of OA, UA, and MA on in vitro ruminal fermentation in comparison with monensin ( MON ). The study consisted of two experiments conducted as randomized complete block designs using bahiagrass hay or a high-concentrate mixed ration as basal substrates. In the first experiment ( Exp. 1 ), a batch culture was performed with increasing doses of OA, UA, or MA. In Exp. 2, to increase the solubility of OA, two chemical forms were evaluated: a sodium salt ( OA-NA ) or a phyto-phospholipid complex ( OA-PHYT ) at 0, 4, 40, 100, and 200 mg/L of incubation inoculum. In both experiments, the dose 0 was used as control ( CTL ) and monensin ( MON ) as a positive control. Data were analyzed as a randomized complete block design with a factorial arrangement of treatments. For Exp. 2, orthogonal polynomial contrasts, adjusted for unequal spacing were used to determine the linear effects of increasing doses of OA-NA and OA-PHYT. In Exp. 1, OA reduced the concentration of CH 4 in the high-concentrate substrate compared with CTL ( P = 0.04). In Exp. 2 the total gas production was linearly decreased with increasing doses of OA-NA in both substrates ( P ≤ 0.02). Furthermore, OA-NA and OA-PHYT decreased in vitro organic matter digestibility ( P < 0.01) in the bahiagrass substrate to the same extent that MON did. However, the concentration of CH 4 /g of incubated DM was only reduced by the highest doses of OA-NA ( P < 0.02). Lastly, no effects were observed for total VFA nor the VFA profile; however, OA-NA linearly decreased the A:P ratio in the bahiagrass substrate ( P = 0.03). In conclusion, the acid form of OA as well as the sodium salt and phyto-phospholipid complex of OA were able to modify some fermentation parameters in this study; however, the magnitude of the responses was lower compared with monensin. Future studies should test OA in vivo to determine if the effects on ruminal fermentation observed here can translate into improve production efficiency while reducing carbon emissions., (© The Author(s) 2022. Published by Oxford University Press on behalf of the American Society of Animal Science.)

Evidence supports a causal link between anomalous intestinal function and impaired performance in dairy cows. Consequently, digesta pH values obtained from colon, cecum, and rectum are increasingly used to monitor intestinal function in dairy cows. We conducted a study to describe the daily dynamics of fecal pH in lactating dairy cows. The study lasted 4 d and individual records of dry matter intake, milk yield, and fecal pH were taken. Samples of feces were taken every 4 h during the 4-d study, and sampling time was adjusted ahead by 1 h daily so that a sample was obtained for each 1-h interval of the day. Data were analyzed using a mixed-effect model including time as fixed effect and cow as a random factor. We performed a cosinor analysis using pH data at different time points to determine whether fecal pH followed a biorhythmic pattern. On average, cows consumed 19.1 ± 1.55 kg/d of dry matter and produced 26.3 ± 4.16 kg/d of milk. The most relevant results confirmed a biorhythmic pattern for feces pH around feeding time: mesor (midline estimating statistic of rhythm) 6.20, amplitude 0.28, and acrophase 5.66. Additionally, we found a positive relationship between dry matter intake and amplitude, possibly because of an increase in the amount of fermentable carbohydrate reaching the hindgut in response to increasing intake. When using fecal pH as an indicator of intestinal function, it is critical to obtain samples at several time points to capture its daily rhythmicity and to report sampling time relative to feeding., (© 2022.)

Increased ambient temperature causes heat stress in mammals, which affects physiological and molecular functions. We have recently reported that the dietary administration of a postbiotic from Aspergillus oryzae (AO) improves tolerance to heat stress in fruit flies and cattle. Furthermore, heat-induced gut dysfunction and systemic inflammation have been ameliorated in part by nutritional interventions. The objective of this study was to characterize the phenotypic response of growing calves to heat stress compared to thermoneutral ad libitum fed and thermoneutral feed-restricted counterparts and examining the physiologic alterations associated with the administration of the AO postbiotic to heat-stressed calves with emphasis on intestinal permeability. In this report, we expand previous work by first demonstrating that heat stress reduced partial energetic efficiency of growth in control (45%) but not in AO-fed calves (62%) compared to thermoneutral animals (66%). While heat stress increased 20% the permeability of the intestine, AO postbiotic and thermoneutral treatments did not affect this variable. In addition, AO postbiotic reduced fecal water content relative to thermoneutral and heat stress treatments. Heat stress increased plasma concentrations of serum amyloid A, haptoglobin and lipocalin-2, and administration of AO postbiotic did not ameliorate this effect. In summary, our findings indicated that heat stress led to reduced nutrient-use efficiency and increased systemic inflammation. Results suggest that the AO postbiotic improved energy-use efficiency, water absorption, and the intestinal permeability in heat stress-mediated increase in gut permeability but did not reduce heat stress-mediated rise in markers of systemic inflammation., (© 2022. The Author(s).)

Medicinal plant extracts are becoming increasingly important as an alternative for traditional drugs against diabetes mellitus (DM). For this reason, we initialized a target-based screening of 111 root extracts from an open access plant extract library (PECKISH) by ascertaining their in-vitro inhibitory efficacy on α-glucosidase. The two most active extracts Geum urbanum L. (roseroot) and Rhodiola rosea L. (avens root) were further tested for their antidiabetic activities in terms of their impact on different regulatory key points of glucose homeostasis. To this end, various enzyme- and cell culture-based in-vitro assays were employed including the determination of sodium-dependent glucose transporter 1 (SGLT1) activity in Caco-2 monolayers by Ussing chambers and of glucose transporter 4 (GLUT4) translocation in a GFP-reporter cell line. Subsequently, the antidiabetic potential of the root extracts were further evaluated in in-vivo models, namely hen's eggs test and the fruit fly Drosophila melanogaster . Avens root extract was found to be a more potent inhibitor of the enzymes α-glucosidase and dipeptidyl peptidase-4 (DPP4) than roseroot extract. Most importantly, only avens root extract exhibited antidiabetic activity in the two in-vivo models eliciting a reduced blood glucose level in the in-ovo model and a decline of the triglyceride level in a dietary starch-induced D. melanogaster obesity model. Analyses of the polyphenolic composition of the avens root extract by HPLC revealed a high content of ellagic acid and its derivatives as well as ellagitannins such as pedunculagin, stenophyllanin, stachyurin, casuarinin and gemin A. In conclusion, avens root extract represents a promising medicinal plant that should be considered in further in-vivo studies on hyperglycemia in laboratory rodents and humans., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Günther, Rimbach, Nevermann, Neuhauser, Stadlbauer, Schwarzinger, Schwarzinger, Ipharraguerre, Weghuber and Lüersen.)

Heat stress is detrimental to food-producing animals and animal productivity remains suboptimal despite the use of heat abatement strategies during summer. Global warming and the increase of frequency and intensity of heatwaves are likely to continue and, thus, exacerbate the problem of heat stress. Heat stress leads to the impairment of physiological and cellular functions of ectothermic and endothermic animals. Therefore, it is critical to conceive ways of protecting animals against the pathological effects of heat stress. In experiments with endothermic animals highly sensitive to heat (Bos taurus), we have previously reported that heat-induced systemic inflammation can be ameliorated in part by nutritional interventions. The experiments conducted in this report described molecular and physiological adaptations to heat stress using Drosophila melanogaster and dairy cow models. In this report, we expand previous work by first demonstrating that the addition of a postbiotic from Aspergillus oryzae (AO) into the culture medium of ectothermic animals (Drosophila melanogaster) improved survival to heat stress from 30 to 58%. This response was associated with downregulation of genes involved in the modulation of oxidative stress and immunity, most notably metallothionein B, C, and D. In line with these results, we subsequently showed that the supplementation with the AO postbiotic to lactating dairy cows experiencing heat stress decreased plasma concentrations of serum amyloid A and lipopolysaccharide-binding protein, and the expression of interleukin-6 in white blood cells. These alterations were paralleled by increased synthesis of energy-corrected milk and milk components, suggesting enhanced nutrient partitioning to lactogenesis and increased metabolic efficiency. In summary, this work provides evidence that a postbiotic from AO enhances thermal tolerance likely through a mechanism that entails reduced inflammation.

Plant extracts have been widely used in animal production systems due to the benefits promoted by their bioactive components, mainly through their antioxidant effects and positive effects on animal growth, health, and meat quality. We determined whether bioactive compounds (BC) from grape (Vitis vinifera), olive (Olea europaea), and pomegranate (Punica granatum) have beneficial effects on lamb growth while controlling gastrointestinal parasitism and reducing skeletal lipid peroxidation in muscle. Fourteen lambs (4 to 5 mo of age) were housed in individual pens and assigned to two treatment groups (seven animals/group), where they received: 1) a basal diet of beet pulp:soybean meal (90:10) (CONTROL) and 2) the same diet, but containing 0.3% of BC extracted from grape, olive, and pomegranate (BNP). After 21 d of consuming their respective rations (period 1), all lambs were dosed with 10,000 L3 stage larvae of Haemonchus contortus. Intake, production, and physiological parameters were determined before infection (period 1), after oral dosage with L3 (period 2), and during early (period 3) and later (period 4) developmental stages of infection. Groups of animals did not differ in their ration intake or average daily gain, either before or after the infection, or in their parasitic burdens estimated through fecal egg counts (P > 0.05). Lambs under BNP showed greater feed efficiency before infection (P < 0.001), but the pattern reversed after infection. In addition, the inclusion of plant bioactives to the diet did not have an effect (P > 0.05) on blood or lipid peroxidation in muscle or on hemogram, serum concentration of haptoglobin, and immunoglobulin E. These results could be explained by low dietary doses and constrained absorption or ruminal inactivation of these compounds. Changes in feed efficiencies suggest a negative interaction between BC in the diet and parasitism, which warrants further research., (© The Author(s) 2021. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Lithium (Li) is an important micronutrient in human nutrition, although its exact molecular function as a potential essential trace element has not yet been fully elucidated. It has been previously shown that several mineral waters are rich and highly bioavailable sources of Li for human consumption. Nevertheless, little is known about the extent in which other beverages contribute to the dietary Li supply. To this end, the Li content of 160 different beverages comprising wine and beer, soft and energy drinks and tea and coffee infusions was analysed by inductively coupled plasma mass spectrometry (ICP-MS). Furthermore, a feeding study in Drosophila melanogaster was conducted to test whether Li derived from selected beverages changes Li status in flies. In comparison to the average Li concentration in mineral waters (108 µg/L; reference value), the Li concentration in wine (11.6 ± 1.97 µg/L) and beer (8.5 ± 0.77 µg/L), soft and energy drinks (10.2 ± 2.95 µg/L), tea (2.8 ± 0.65 µg/L) and coffee (0.1 ± 0.02 µg/L) infusions was considerably lower. Only Li-rich mineral water (~1600 µg/L) significantly increased Li concentrations in male and female flies. Unlike mineral water, most wine and beer, soft and energy drink and tea and coffee samples were rather Li-poor food items and thus may only contribute to a moderate extent to the dietary Li supply. A novelty of this study is that it relates analytical Li concentrations in beverages to Li whole body retention in Drosophila melanogaster .

Gamma-cyclodextrin (γCD) is a cyclic oligosaccharide consisting of eight α-(1,4)-linked glucopyranose subunits, which is often used in the food and pharmaceutical industries. However, little is known regarding the metabolic activity of "empty" γCD per se. Therefore, in the present study young C57BL/6 male mice received a control diet (CON) or an experimental diet that was supplemented with 12.88% γCD exchanged against corn starch. After 6 weeks of treatment, the voluntary wheel running activity was monitored and the muscle strength of mice was measured by employing Kondziela's inverted screen test and forelimb grip strength assay. The γCD-treated mice covered a significantly larger distance per night (CON 8.6 km, γCD 12.4 km) and were significantly longer active (CON 340 min, γCD 437 min). Moreover, γCD-treated mice significantly performed better at the inverted screen test indicated by an enhanced Kondziela score (CON 3.10, γCD 4.63). These data suggest that dietary γCD leads to an increased endurance. We also found a slightly anti-glycemic effect of γCD during oral glucose tolerance test. However, our mice from the γCD group exhibited no difference in terms of GLUT2 protein level in ileum tissue nor increased muscle glycogen storage. Furthermore, γCD exhibited no DPP-4 inhibitory activity in vitro. By analysing candidate muscle genes and proteins related to endurance and muscle performance we did not observe any differences in terms of Sirt1, Pgc1α, Cpt1b, Mef2c, Myh1 and Myh2 gene expression levels as well as total oxidative phosphorylation (OXPHOS), mtTFA and GLUT4 protein expression levels in skeletal muscle in response to γCD. We could not fully establish the exact underlying molecular mechanisms of the fitness improvement by dietary γCD which warrants further investigations.

The present study aims to investigate the effects of supplementing broiler diets with a bioactive olive pomace extract (OE) from Olea europaea on growth performance, digestibility, gut microbiota, bile acid composition, and immune response. To this end, three hundred and six 1-day-old broiler chickens (Ross 308) were housed in floor pens (6 pens/treatment, with 17 birds/pen). Animals were fed with a standard non-medicated starter diet for 21 D, and from 22 to 42 D of age with their respective experimental diet: a negative control with no additives (Control), a positive control with 100 ppm of monensin (Monensin) and the basal diet supplemented with 750 ppm of an OE (Lucta S.A., Spain). Feed intake and growth rate were monitored weekly throughout the trial. From 21 to 42 D of age, no significant differences in feed intake were observed among dietary treatments; however, lower average daily gain and higher feed conversion ratio (P < 0.05) was observed in birds fed the Control compared to Monensin and OE groups. Performance of birds fed OE or Monensin was similar throughout the trial. The apparent ileal digestibility of crude protein was higher in birds fed Monensin than Control treatment (P < 0.05). No significant changes on bacterial composition at a family level were observed in the caeca of birds fed the experimental diets. Moreover, no significant differences on plasma and intestinal bile acid composition were observed among treatments. Birds fed the OE showed a significant decrease of IL-8 expression in the ileum (P < 0.05). Additionally, the expression of TGF-β4, and Bu-1 was significantly upregulated (P < 0.01) in broilers fed the OE and Monensin diets compared to those fed the Control. In conclusion, the inclusion of 750 ppm of a bioactive olive pomace extract from Olea europaea in broiler chicken diets improved animal growth likely as result of its anti-inflammatory properties., (Copyright © 2019 The Author(s). Published by Elsevier Inc. All rights reserved.)

To gain a better understanding of how nitrate may affect carbohydrate and lipid metabolism, female wild-type mice were fed a high-fat, high-fructose diet supplemented with either 0, 400, or 800 mg nitrate/kg diet for 28 days. Additionally, obese female db/db mice were fed a 5% fat diet supplemented with the same levels and source of nitrate. Nitrate decreased the sodium-dependent uptake of glucose by ileal mucosa in wild-type mice. Moreover, nitrate significantly decreased triglyceride content and mRNA expression levels of Pparγ in liver and Glut4 in skeletal muscle. Oral glucose tolerance as well as plasma cholesterol, triglyceride, insulin, leptin, glucose and the activity of ALT did not significantly differ between experimental groups but was higher in db/db mice than in wild-type mice. Nitrate changed liver fatty acid composition and mRNA levels of Fads only slightly. Further hepatic genes encoding proteins involved in lipid and carbohydrate metabolism were not significantly different between the three groups. Biomarkers of inflammation and autophagy in the liver were not affected by the different dietary treatments. Overall, the present data suggest that short-term dietary supplementation with inorganic nitrate has only modest effects on carbohydrate and lipid metabolism in genetic and dietary-induced mouse models of obesity., Competing Interests: AM is an employee of Yara, and IRI provides consulting services to Yara. All authors had complete and independent control over the study design, analysis and interpretation of data, report writing and publication, regardless of results., (Copyright © 2020 JCBN.)

Weaning is one of the most stressful periods in the life of a ruminant. Several factors entrenched within typical management practices pose challenges to the calf gastrointestinal health. Weaning is associated with losses in BW and feed intake. In addition, increasing highly fermentable carbohydrates in the diet at the expense of physically effective fiber after weaning predisposes the development of rumen acidosis and increases the concentration of endotoxin in rumen fluid and the permeability of the lower gut to luminal contents. Endotoxin translocation can elicit immune activation, shifting the metabolic priorities toward the immune system, which if sustained over time can hinder animal health and performance. Strategic supplementation of additives with anti-inflammatory capacity could represent a suitable approach to decrease systemic inflammation, restoring barrier function to luminal contents. Bioactive extracts from Olea europaea have anti-inflammatory activity and have been shown to reduce systemic inflammation in other animal models. A generalized randomized block design was used to evaluate the impact of feeding an olive oil bioactive extract (OBE) to newly weaned heifers injected intravenously with sequentially increasing doses of lipopolysaccharide (LPS). A total of 36 heifers, distributed across 3 experimental periods, were randomly assigned to 1 of 4 treatments that consisted of intravenous injection of either saline (CTL-) or with 6 sequentially increasing doses of LPS (0.10, 0.25, 0.50, 0.75, 1.00, and 1.25 µg/kg of BW) over a 10-d period (CTL+), and CTL+ plus dietary supplementation with a low (OBE-L; 0.04% of diet DM) or a high (OBE-H; 0.16% of diet DM) dose of OBE. Feeding OBE reduced some of the negative effects of prolonged immune activation with LPS, such as improved DMI and decreased intravaginal temperature in some, but not all of the days of LPS challenge (P < 0.05). In addition, feeding OBE reduced circulating concentration of inflammatory markers such as IL-6 and haptoglobin (P < 0.05). Heifers supplemented with OBE had reduced cell surface expression of the cluster of differentiation 14 (CD14) in monocyte cells (P < 0.01), a key receptor for LPS recognition, which was correlated with a faster recovery of immune cell counts in plasma. In conclusion, dietary supplementation with OBE was successful in mitigating the negative effects of sustained immune activation in newly weaned heifers., (© The Author(s) 2019. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Enteroendocrine L cells and glucagon-like peptide 2 (GLP-2) secretion are activated in the intestinal adaptation process following bowel resection in patients with short bowel syndrome. We hypothesized that enteral activation of Takeda G protein-coupled receptor 5 (TGR5), expressed in enteroendocrine L cells, could augment endogenous GLP-2 secretion and the intestinal adaptation response. Our aim was to assess the efficacy of different TGR5 agonists to stimulate GLP-2 secretion and intestinal adaptation in a piglet short-bowel model. In study 1 , parenterally fed neonatal pigs ( n = 6/group) were gavaged with vehicle, olive extract (OE; 10 or 50 mg/kg), or ursolic acid (UA; 10 mg/kg), and plasma GLP-2 was measured for 6 h. In study 2 , neonatal pigs ( n = 6-8/group) were subjected to transection or 80% mid-small intestine resection and, after 2 days, assigned to treatments for 10 days as follows: 1 ) transection + vehicle (sham), 2 ) resection + vehicle (SBS), 3 ) resection + 30 mg UA (SBS + UA), and 4 ) resection + 180 mg/kg OE (SBS + OE). We measured plasma GLP-2, intestinal histology, cell proliferation, and gene expression, as well as whole body citrulline-arginine kinetics and bile acid profiles. In study 1 , GLP-2 secretion was increased by UA and tended to be increased by OE. In study 2 , SBS alone, but not additional treatment with either TGR5 agonist, resulted in increased mucosal thickness and crypt cell proliferation in remnant jejunum and ileum sections. SBS increased biliary and ileal concentration of bile acids and expression of inflammatory and farnesoid X receptor target genes, but these measures were suppressed by UA treatment. In conclusion, UA is an effective oral GLP-2 secretagogue in parenterally fed pigs but is not capable of augmenting GLP-2 secretion or the intestinal adaptation response after massive small bowel resection. NEW & NOTEWORTHY Therapeutic activation of endogenous glucagon-like peptide 2 (GLP-2) secretion is a promising strategy to improve intestinal adaptation in patients with short bowel syndrome. This study in neonatal pigs showed that oral supplementation with a selective Takeda G protein-coupled receptor 5 (TGR5) agonist is an effective approach to increase GLP-2 secretion. The results warrant further study to establish a more potent oral TGR5 agonist that can effectively improve intestinal adaptation in pediatric patients with SBS.

The health and life span of Drosophila melanogaster are partly determined by intestinal barrier integrity, metabolic rate as well as stress response and the expression of longevity-associated genes, depending on genetic and dietary factors. Ursolic acid (UA) is a naturally occurring triterpenoid exhibiting potential antimicrobial, anti-inflammatory, and antiobesity activity and counteracting age-related deficits in muscle strength. In this study, UA was dietarily administered to w 1118 D. melanogaster which significantly elongated the health and life span of males. Spargel (srl) is the Drosophila orthologue of mammalian peroxisome proliferator-activated receptor-gamma coactivator 1 α(PGC1α), an important regulator of energy homeostasis and mitochondrial function. Our results indicate that the health-promoting effect of UA, demonstrated by a significant increase in climbing activity, occurs via an upregulation of srl expression leading to a metabolic shift in the fly without reducing fecundity or gut integrity. Moreover, UA affected the flies' microbiota in a manner that contributed to life span extension. Srl expression and microbiota both seem to be affected by UA, as we determined by using srl-mutant and axenic flies. © 2018 BioFactors, 45(2):169-186, 2019., (© 2018 International Union of Biochemistry and Molecular Biology.)

Recent studies suggest that the use of vegetable oils at expense of fish oil in aquaculture feeds might have potential negative effects on fish redox homeostasis and adiposity. Resveratrol (RESV) is a lipid-soluble phytoalexin present in fruits and vegetables with proven in vivo antioxidant function in animals. The present study aims to assess the potential use of RESV in Atlantic salmon feeds. To this end, post-smolt salmons with an initial BW of 148±3 g were fed four experimental diets for 15 weeks. A diet low in fish oil served as a control and was supplemented with 0, 0.5, 1.5 and 2.5 g/kg of RESV, respectively. The effect of the experimental diets on animal performance, tissue fatty acid composition, and the expression of genes encoding proteins involved in antioxidant signalling, lipid peroxidation, and metabolism were studied. Resveratrol significantly reduced feed intake and final BW of the salmon. Feeding RESV did not affect the sum of saturated and monounsaturated fatty acids or total lipids in the fillet. While the content of total polyunsaturated fatty acids was not affected, the percentages of some fatty acids in the liver and fillet were changed by RESV. Furthermore, in liver, the relative expression of glutathione peroxidase 4b, nuclear factor-like 2, and arachidonate 5-lipoxygenase remained unchanged across treatment groups. In conclusion, the negative impact of dietary RESV on FI and hence reduction of the BW discourages its inclusion in low fish oil diets for Atlantic salmon.

Feeding behavior in dairy cattle has a significant impact on feed efficiency, which is important for increasing the profitability of livestock and, at the same time, reducing the environmental impact. Feeding behavior can be measured by feeding time, meal duration, meal frequency, feeding rate, and rumination time. Higher feed intake is related to lower feed efficiency; whereas, an increase in feeding time facilitates chewing, reduces feed particle size and increases its digestibility. More frequent and shorter meals are usually associated with a more efficient use of feed due to improvement of feed digestibility. Rumination time is positively associated with milk production. Impaired health is associated with variations in feeding behavior, which can be used to identify and predict some diseases such as ketosis, mastitis, or lameness. Changes in rumination time are also a reliable indicator of mastitis, lameness, ketosis, abomasal displacement, and the onset of calving. In addition to the cause-effect relationship between disease and changes in feeding behavior, there are also some cases in which changes in feeding behavior may lead to an increased risk of disease, as exemplified by the relationship of feeding rate with sub-acute ruminal acidosis. Feeding behavior is regulated by internal and external factors and some of them are relevant for animal welfare. The main welfare-associated factors influencing feeding behavior are social behavior and temperament, and environmental effects. Cattle are social animals and hierarchy has a notable impact on feeding behavior, especially when access to feed is limited. Competition for feed causes a reduction in the average feeding time but increases feeding rate. Excitable animals visit the feeder more often and spend less time per meal. High environmental temperature affects feeding behavior, as heat-stressed cattle change their feeding pattern by concentrating the feeding events in crepuscular hours, leading to an increased risk of sub-acute ruminal acidosis. In conclusion, feeding behavior is a determinant feature for improving efficiency, productivity and welfare of dairy cattle. Routine assessment of feeding behavior allows monitoring of health and production status of dairy cattle at the individual and farm level, which is a useful tool to optimize the management of livestock.

Plant bioactives can potentially benefit herbivores through their effects on health and nutrition. The objective of this study was to determine the importance of polyphenols and terpenes on the ability of lambs to self-select these compounds when challenged by a parasitic infection and the subsequent impact on their health and productivity. Thirty-five lambs were housed in individual pens and assigned to five treatment groups (7 animals/group), where they received: 1) A basal diet of beet pulp:soybean meal (90:10) (CONTROL); 2) The same diet, but containing 0.3% of bioactive natural plant compounds extracted from grape, olive and pomegranate (BNP); 3) A simultaneous offer of the diets offered to the Control and BNP groups (Choice-Parasitized; CHP-1); 4) The Control diet, and when lambs developed a parasitic infection, the choice described for CHP-1 (CHP-2); and 5) The same choice as CHP-1, but animals did not experience a parasitic burden (Choice-Non-Parasitized; CHNP). Lambs, except CHNP, were dosed with 10,000 L 3 stage larvae of Haemonchus contortus. Infected lambs under choice treatments (CHP-1 and CHP-2) modified their feeding behavior in relation to the CHNP group as they increased their preference for the feed containing polyphenols and terpenes, interpreted as a behavior aimed at increasing the likelihood of encountering medicinal compounds and nutrients in the environment that restore health. This change in behavior corresponded with an improvement in feed conversion efficiency. However, an increased preference for the diet with added plant bioactives did not have an effect on parasitic burdens, hematological parameters, blood oxidation, or serum concentration of IgE., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Scope: Primary bile acids are produced in the liver, whereas secondary bile acids, such as lithocholic acid (LCA), are generated by gut bacteria from primary bile acids that escape the ileal absorption. Besides their well-known function as detergents in lipid digestion, bile acids are important signaling molecules mediating effects on the host's metabolism., Methods and Results: Fruit flies (Drosophila melanogaster) are supplemented with 50 μmol L -1 LCA either for 30 days or throughout their lifetime. LCA supplementation results in a significant induction of the mean (+12 days), median (+10 days), and maximum lifespan (+ 11 days) in comparison to untreated control flies. This lifespan extension is accompanied by an induction of spargel (srl), the fly homolog of mammalian PPAR-γ co-activator 1α (PGC1α). In wild-type flies, the administration of antibiotics abrogates both the LCA-mediated lifespan induction as well as the upregulation of srl., Conclusion: It is shown that the secondary bile acid LCA significantly induces the mean, the median, and the maximum survival in D. melanogaster. Our data suggest that besides an upregulation of the PGC1α-homolog srl, unidentified alterations in the structure or metabolism of the gut microbiota contribute to the longevity effect mediated by LCA., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Fibroblast growth factor-19 (FGF19) is an emerging endocrine factor involved in the regulation of bile acid homeostasis and energy metabolism in rodents and humans. In pigs, however, the FGF19 system remains largely unexplored. This study was designed to investigate the developmental regulation of the FGF19 system in domestic pigs. Samples of intestinal sections, liver, and plasma were collected from 24 pigs ( n = 6) at four developmental stages (birth, preweaning, postweaning, and adulthood). In the intestine, expression of the farnesoid X receptor (FXR) and FGF19 showed a congruent time- and region-dependent regulation, beginning soon after birth to achieve maximal expression in ileum during adulthood. The same temporal pattern was followed by the circulating concentration of FGF19, and these changes were accompanied by a time-related increase in the ileal proportion of bile acids that potently activate FXR. Conversely, genes belonging to the FGF19 signaling machinery achieved maximal expression in the small intestine at birth to decrease sharply afterward. In the liver, gene expression of FGF19 receptors and enzymes involved in bile acid biosynthesis paralleled after-birth changes in plasma concentration of this enterokine and attained a maximum during postweaning when plasma FGF19 was the lowest. Although detectable at birth, the hepatic expression of genes belonging to the bile acid-FXR-FGF19 pathway was low before the onset of enteral feeding. In summary, the porcine FGF19 system is present from birth, operative before the onset of enteral feeding, and regulated in a temporal and section-specific manner. NEW & NOTEWORTHY Fibroblast growth factor-19 (FGF19) is an emerging endocrine factor. The domestic pig is a translational model of value in biomedical research. We show for the first time that in pigs the intestinal FGF19 system is present from birth, operative before the onset of enteral feeding, and regulated in a temporal and section-specific manner. This work identifies pigs as a suitable model for investigating the implications of FGF19 signaling within and beyond the gut-liver axis.

Non-alcoholic fatty liver disease (NAFLD) affects 25% of adults and at present no licensed medication has been approved. Despite its complex patho-physiology, dietary strategies aiming at delaying or preventing NAFLD have taken a reductionist approach, examining the impact of single components. Accumulating evidence suggests that n-3 LC-PUFAs are efficacious in regulating lipogenesis and fatty acid oxidation. In addition, plant derived flavonoids are also emerging as a dietary strategy for NAFLD prevention, with efficacy attributed to their insulin sensitising and indirect antioxidant effects. Based on knowledge of their complementary molecular targets, we aimed to demonstrate that the combination of n-3 LC-PUFA (n-3) and flavan-3-ols (FLAV) prevents NAFLD. In a high-fat high-fructose (HF/HFr) fed C57Bl/6J mouse model, the independent and interactive impact of n-3 and FLAV on histologically defined NAFLD, insulin sensitivity, weight gain, intestinal and hepatic gene expression, intestinal bile acids were examined. Only the combination of FLAV and n-3 (FLAVn-3) prevented steatosis as evidenced by a strong reduction in hepatocyte ballooning. While FLAV reduced body (-28-30%), adipose tissue (-45-50%) weights and serum insulin (-22-25%) as observed following an intra-peritoneal glucose tolerance test, n-3 downregulated the expression of Srebf1 and the lipogenic genes (Acaca, Fasn). Significant impacts of interventions on intestinal bile acid metabolism, farnesoid X receptor (Fxr) signalling in the intestine and liver, and hepatic expression of fatty acid transporters (Fabp4, Vldlr, Cd36) were also evident. FLAVn-3 may be a novel intervention for NAFLD. Future research should aim to demonstrate its efficacy in the prevention and treatment of human NAFLD., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In this study we addressed the questions whether an Atlantic brown algae extract (BAE) affects diet induced obesity in mice and which would be the primary targets and underlying key mechanisms. Male C57 BL/6 mice were fed a hypercaloric diet, referred to as high fat diet (HFD), supplemented with a freeze-dried aqueous BAE from Saccorhiza polyschides (5 %) for 8 months. Compared to the control group, dietary BAE supplementation significantly attenuated increase in body weight and fat mass. We observed apparent metabolic improvement including normalization of blood glucose, reduced plasma leptin, reduced fecal bile salt hydrolase activity with lower microbial production of toxic bile acid metabolites in the gut and increased systemic bile acid circulation in BAE-fed mice counteracting adverse effects of long term HFD feeding. Survival of mice receiving dietary BAE supplementation appeared slightly enhanced; however, median and maximal life spans as well as hepatic mTOR activation were not significantly different between BAE and control mice. We suggest that the beneficial metabolic effects of our BAE are at least partly mediated by alterations in gut microbiota associated with fermentation of indigestible polysaccharides that are major components of brown algae such as alginates and fucoidans. We moreover propose a multi-factorial mechanism that involves profound alterations in bile acid homeostasis, changes in intestinal and systemic glucose metabolism likely including increased intestinal gluconeogenesis, increased activity of the intestinally derived hormone GLP-1 contributing to promote systemic insulin sensitivity, and inhibition of α-amylase activity, which expectably limits dietary carbohydrate digestion and glucose release., Competing Interests: CONFLICTS OF INTEREST The authors declare no conflicts of interest.

Subclinical chronic inflammation (SCI) is associated with impaired animal growth. Previous work has demonstrated that olive-derived plant bioactives exhibit anti-inflammatory properties that could possibly counteract the growth-depressing effects of SCI. To test this hypothesis and define the underlying mechanism, we conducted a 30-day study in which piglets fed an olive-oil bioactive extract (OBE) and their control counterparts (C+) were injected repeatedly during the last 10 days of the study with increasing doses of Escherichia coli lipopolysaccharides (LPS) to induce SCI. A third group of piglets remained untreated throughout the study and served as a negative control (C-). In C+ pigs, SCI increased the circulating concentration of interleukin 1 beta (p < 0.001) and decreased feed ingestion (p < 0.05) and weight gain (p < 0.05). These responses were not observed in OBE animals. Although intestinal inflammation and colonic microbial ecology was not altered by treatments, OBE enhanced ileal mRNA abundance of tight and adherens junctional proteins (p < 0.05) and plasma recovery of mannitol (p < 0.05) compared with C+ and C-. In line with these findings, OBE improved transepithelial electrical resistance (p < 0.01) in TNF-α-challenged Caco-2/TC-7 cells, and repressed the production of inflammatory cytokines (p < 0.05) in LPS-stimulated macrophages. In summary, this work demonstrates that OBE attenuates the suppressing effect of SCI on animal growth through a mechanism that appears to involve improvements in intestinal integrity unrelated to alterations in gut microbial ecology and function.

Diarrhea episodes in dairy calves involve profound alterations in the mechanism controlling gut barrier function that ultimately compromise intestinal permeability to macromolecules, including pathogenic bacteria. Intestinal dysfunction models suggest that a key element of intestinal adaptation during the neonatal phase is the nutrient-induced secretion of glucagon-like peptide (GLP)-2 and associated effects on mucosal cell proliferation, barrier function, and inflammatory response. Bioactive molecules found in Olea europaea have been shown to induce the release of regulatory peptides from model enteroendocrine cells. The ability to enhance GLP-2 secretion via the feeding of putative GLP-2 secretagogues is untested in newborn calves. The objectives of this study were to determine whether feeding a bioactive extract from Olea europaea (OBE) mixed in the milk replacer (1) can stimulate GLP-2 secretion beyond the response elicited by enteral nutrients and, thereby, (2) improve intestinal permeability and animal growth as well as (3) reduce the incidence of diarrhea in preweaning dairy calves. Holstein heifer calves (n = 60) were purchased, transported to the research facility, and blocked by body weight and total serum protein and assigned to 1 of 3 treatments. Treatments were control (CON), standard milk replacer (MR) and ad libitum starter; CON plus OBE added into MR at 30 mg/kg of body weight (OBE30); and CON plus OBE added into MR at 60 mg/kg of body weight (OBE60). The concentration of GLP-2 was measured at the end of wk 2. Intestinal permeability was measured at the onset of the study and the end of wk 2 and 6, with lactulose and d-mannitol as markers. Treatments did not affect calf growth and starter intake. Compared with CON, administration of OBE60 increased the nutrient-induced response in GLP-2 by about 1 fold and reduced MR intake during the second week of study. Throughout the study, however, all calves had compromised intestinal permeability and a high incidence of diarrhea. The GLP-2 response elicited by OBE60 did not improve intestinal permeability (lactulose-to-d-mannitol ratio) and incidence of diarrhea over the course of the preweaning period. The response in GLP-2 secretion to the administration of OBE reported herein warrants further research efforts to investigate the possibility of improving intestinal integrity through GLP-2 secretion in newborn calves., (Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

An olive oil bioactive extract (OBE) rich in bioactive compounds like polyphenols, triterpenic acids, long-chain fatty alcohols, unsaturated hydrocarbons, tocopherols and sterols was tested (0, 0·08, 0·17, 0·42 and 0·73 % OBE) in diets fed to sea bream (Sparus aurata) (initial weight: 5·4 (sd 1·2) g) during a 90-d trial (four replicates). Fish fed diets containing 0·17 and 0·42 % OBE were 5 % heavier (61·1 (sd 1·6) and 60·3 (sd 1·1) g, respectively) than those of the control group (57·0 (sd 0·7) g), although feed conversion ratio and specific feed intake did not vary. There were no differences in lipid peroxidation (LPO) levels, catalase, glutathione reductase and glutathione S-transferase activities in the intestine and liver, although there was a tendency of lower intestinal and hepatic LPO levels in fish fed OBE diets. No differences in villus size were found among treatments, whereas goblet cell density in the control group was on average14·3 % lower than in fish fed OBE diets. The transcriptomic profiling of intestinal markers, covering different biological functions like (i) cell differentiation and proliferation, (ii) intestinal permeability, (iii) enterocyte mass and epithelial damage, (iv) IL and cytokines, (v) pathogen recognition receptors and (vi) mitochondria function, indicated that among the eighty-eight evaluated genes, twenty-nine were differentially expressed (0·17 % OBE diet), suggesting that the additive has the potential of improving the condition and defensive role of the intestine by enhancing the maturation of enterocytes, reducing oxidative stress, improving the integrity of the intestinal epithelium and enhancing the intestinal innate immune function, as gene expression data indicated.

Glucagon-like peptide 2 (GLP-2) is a peptide released by the lower gut that has potent trophic and restorative effects on the intestinal epithelium. Two experiments were conducted to assess the effects of feeding rate and either metabolizable or nonmetabolizable glucose supplementation on GLP-2 concentrations in plasma and intestinal development in Holstein calves. In the first experiment, 48 newborn calves were assigned to 12 treatments (n=4) corresponding to the factorial combination of 4 milk feeding amounts [1.75, 1.32, 0.88, and 0.44% of body weight (BW) as dry matter (DM)] and 3 oral supplementation treatments (nonsupplemented, glucose-supplemented, and 3-O-methyl glucose-supplemented). In the second experiment 30 newborn calves (n=10) were fed milk at a fixed rate of 1.75% of BW as DM and assigned to the same glucose supplementation treatments used in experiment 1 to investigate effects on intestinal development. In the first experiment, we found a saturating response of plasma GLP-2 to increasing feeding levels. The feeding rate at which 50% of the maximal GLP-2 release occurred was estimated to be 0.53% of BW as DM or 30.3% of the maximum feeding rate (1.75% of BW as DM), whereas maximal secretion was estimated to be about 98.6 pmol/L. In turn, feeding 75, 50, or 25% of the maximal feeding rate (i.e., 1.75% BW as DM) resulted in plasma GLP-2 concentrations 87, 72, and 49% of that in fully fed calves, respectively. Neither metabolizable nor nonmetabolizable glucose supplementation affected GLP-2 secretion and no interaction with feed intake level was detected. In the second experiment, no effect of glucose supplementation was observed on intestinal growth, mucosal cell proliferation, or expression of genes related to the actions of GLP-2. Nonetheless, we observed that a pool of genes of the GLP-2 signaling pathway was more abundantly and coordinately regulated in the colon than in the ileum of these animals, indicating an opportunity for dietary induction of the peptide in this organ. In conclusion, during this experiment, plasma GLP-2 concentrations responded in a diminishing return fashion to milk intake but not to glucose supplementation, even at milk consumption levels of only 0.4% of BW as DM., (Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Background: Previous work showed that weaning stress causes gut barrier dysfunction partly by triggering the release of corticotropin releasing factor (CRF) and thereby inducing the degranulation of intestinal mast cell (MC). This study investigated the hypothesis that attenuating the weaning-induced activation of the CRF-MC axis via administration of a MC stabilizing agent (cromolyn) may improve gut permeability and piglet performance after weaning., Results: To test the hypothesis twenty piglets were weaned (20 ± 1.0 d of age; 6.4 ± 0.4 kg of BW) and injected intraperitoneally with saline (control, n = 10) or 20 mg/kg BW of sodium cromolyn (cromolyn, n = 10) at - 0.5, 8 and 16 h relative to weaning. Piglets were housed individually and fed ad libitum a pre-starter diet from one to 15 d post-weaning followed by a starter diet until the end of the study on d 36. Cromolyn improved intestinal permeability as indicated by the reduced recovery of cobalt and mannitol in plasma samples. Cromolyn treated pigs consumed more feed (369 vs. 313 g/d; P < 0.009), gained more BW (283 vs. 238 g/d; P < 0.006), and grew more efficiently (0.60 vs. 0.40; P < 0.042) than their control counterparts. As a result, cromolyn treated pigs were 1.4 kg heavier than those in the control group by d 36 after weaning (16.5 vs. 17.9 kg; P < 0.002)., Conclusions: In agreement with our hypothesis, present data indicate that the cromolyn-mediated improvement of intestinal permeability is associated with enhanced pig performance after weaning.

Background: Early weaning (EW) results in a transient period of impaired integrity of the intestinal mucosa that may be associated with reduced plasma concentration of glucagon-like peptide-(GLP) 2. We have previously shown that intragastric infusion of chenodeoxycholic acid (CDC) increases circulating GLP-2 in early-weaned piglets. The aim of this study was to expand previous work to establish whether feeding piglets a cereal-based diet supplemented with CDC can improve gut integrity and animal performance immediately after EW. A cohort of 36 piglets weaned at 20 days of age, 6.2 ± 0.34 kg of body weight (BW) were randomly assigned (n = 18) to receive a standard prestarter diet or the same diet supplemented with 60 mg of CDC per kg of initial BW for ad libitum intake until day 14 postweaning. Thereafter, all pigs were fed the same untreated starter diet for 21 days until the end of the study on day 35. On days 1, 7 and 14 blood samples were collected from 6 pigs per treatment to measure plasma GLP-2. On day 15, 6 pigs per treatment were euthanized to obtain intestinal tissue samples for later histological and gene expression analyses., Results: Supplementing the diet with CDC tended to increase plasma GLP-2 (P < 0.07; 39 %) and the weight of the large intestine (P < 0.10; 11 %), and increased ileal crypt depth (P < 0.04; 15 %) after 14 days of treatment exposure. Although feed intake and BW gain were not affected by treatments, feeding CDC induced the expression of the cytokines TNF-α (P < 0.02; 1.9 fold), IL-6 (P < 0.01; 2.4 fold), and IL-10 (P < 0.006; 2.2 fold) and the tight junctional protein ZON-1 (P < 0.02; 1.5 fold) in the distal small intestine., Conclusions: This study showed that the oral administration of CDC to early-weaned pigs has the potential to improve the protection of the intestinal mucosa independently of relevant changes in gut growth.

In 3 experiments, we assessed preference of recently weaned dairy calves for (1) 8 high-energy feed types [barley meal, corn meal, corn gluten feed (CGF), oat meal, rice meal, sorghum meal, wheat meal, and wheat middlings meal]; (2) 6 high-protein feed types [corn gluten meal (CGM), wheat distillers dried grains, rapeseed meal, soybean meal (SBM), sunflower meal, and pea meal]; and (3) 4 mixtures (50:50) of the highest- and lowest-ranked high-energy and high-protein feeds, to assess whether calves maintain preference for feed ingredients that are included in a mixture. In all experiments, pairwise preference tests were conducted between all feed types (28 different pairwise preference tests in experiment 1, 15 tests in experiment 2, and 6 tests in experiment 3). Each pairwise preference test was conducted by offering ad libitum access to both feed types for 6h. All tests were repeated with 20 Holstein calves. Before this study, calves were offered milk replacer at a rate of 4 L/d and a pelleted starter feed ad libitum. After weaning at 62 d of age, each calf was involved in a pairwise preference test at 3 and 5d postweaning. A preference ratio was calculated for each calf in each test as (intake of feed type A)/(intake of feed type A + intake of feed type B). Preference for feed types was ranked across tests in each experiment using pairwise comparison charts. In experiment 1, the highest-ranked high-energy feed type was wheat meal and the lowest ranked were rice meal and CGF. In experiment 2, the highest-ranked high-protein feed type was SBM and the lowest ranked was CGM. According to the preference rankings from experiments 1 and 2, experiment 3 evaluated (50:50) mixtures of SBM + wheat meal, SBM + CGF, CGM + wheat meal, and CGM + CGF. The mixture of SBM + wheat meal was highest ranked, CGM + CGF was lowest ranked, and the mixtures containing one high-ranked and one low-ranked feed ingredient (SBM + CGF and CGM + wheat meal) were ranked equally. The results of this study indicate that young calves exhibit clear preferences for certain high-energy and high-protein feeds that may be considered highly palatable. Further, preference ranking of feed types provided as 50:50 mixtures was consistent with ranking of individual feed types, suggesting that palatability of mixed starter rations can be improved by inclusion of a preferred feed type., (Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Early weaning is a stressful event characterized by a transient period of intestinal atrophy that may be mediated by reduced secretion of glucagon-like peptide (GLP) 2. We tested whether enterally fed bile acids or plant sterols could increase nutrient-dependent GLP-2 secretion and improve intestinal adaptation in weanling pigs. During the first 6 d after weaning, piglets were intragastrically infused once daily with either deionized water (control), chenodeoxycholic acid (CDC; 60 mg/kg body weight), or β-sitoesterol (BSE; 100 mg/kg body weight). Infusing CDC increased plasma GLP-2 (P < 0.05) but did not affect plasma GLP-1 and feed intake. The intestinal expression of glucagon-like peptide 2 receptor, sodium-dependent bile acid transporter, farnesoid X receptor, and guanosine protein-coupled bile acid receptor genes were not affected by CDC treatment. The intragastric administration of CDC did not alter the weight and length of the intestine, yet increased the activation of caspase-3 in ileal villi (P < 0.02) and the expression of interleukin 6 (P < 0.002) in the jejunum. In contrast, infusing BSE did not affect any of the variables that were measured. Our results show that the enteral administration of the bile acid CDC potentiates the nutrient-induced secretion of endogenous GLP-2 in early-weaned pigs. Bile acid-enhanced release of GLP-2, however, did not result in improved intestinal growth, morphology, or inflammation during the postweaning degenerative phase.

Pig production is a commodity business, which makes it a cost-driven business. Pig producers and their advisors are appropriately reluctant to adopt technologies without confidence that improved production will more than pay for the cost of the technology. Physiological effects of technologies targeting gut sensory pathways must translate to demonstrably improved health and/or productive performance if they are to be adopted. The types and degrees of stressors experienced by pigs in commercial production vary widely and often differ from those in research herds, and those variations influence their productive responses to nutritional and health technologies. Pigs are most vulnerable to disease soon after weaning, and the diets fed to pigs at that time are more expensive and offered in much smaller amounts than those fed later in life. Those factors make it easier to justify expensive dietary technologies for young pigs than for older ones. New developments in gut chemosensing appear important, but their practical application is not yet clear. We suggest investigation of the potential to connect chemical detection by the gut to pig productivity and/or efficiency through these mechanisms: 1) trophic effects on the intestines, which lead to improved enteric health or enhanced nutrient digestion and absorption, 2) enhanced barrier function in the intestinal mucosa, 3) increased feed intake, 4) enhanced insulin secretion and sensitivity, which may be especially useful in lactating sows to improve subsequent reproduction, and 5) other signals triggered by products of enteric fermentation, possibly short-chain fatty acids, that may influence gut integrity, feed intake, and reproductive function. Each of these mechanisms relates to a practical issue in pig production. Practical application would likely be achieved through dietary changes, but separate management factors, drugs, or other interventions may also be developed.

Opioid peptides may participate in the control of feed intake through mechanisms involving pleasure reward linked to consumption of palatable feed. The objective of this study was to determine whether blocking opioid receptors might void oro-sensorial preferences of calves, and affect circulating glucose, insulin, and anorexigenic hormones in fasted and fed calves. Two experiments involved 32 Holstein calves [body weight (BW)=86.5±1.73 kg, age=72±0.6 d]. In experiment 1, all calves received an ad libitum choice of the same feed either unflavored or flavored with a sweetener (Luctarom SFS-R, Lucta, Montornès del Vallès, Spain). Feed consumption was recorded every 2 h from 0800 to 1400 h for 3 consecutive days to verify the establishment of an oro-sensorial preference for sweet feed (SF). The SF was preferred over the control feed (CF) at all recorded times. In experiment 2, calves were subjected to a 2 × 2 factorial design to study the interaction between opioid activity and metabolic state. Half of the calves were fasted for 14 h (FAS), whereas the other half remained well fed (FED). Within each of these groups, at feeding time (0800 h), half of the calves received an i.v. injection of naloxone (NAL, an opioid receptor antagonist; 1 mg/kg of BW) and the other half was injected with saline solution (SAL; 0.9% NaCl). Therefore, treatments were FED-NAL, FED-SAL, FAS-NAL, and FAS-SAL. Blood samples were taken at -10, 20, 180, and 240 min relative to NAL or SAL injections. As expected, cumulative consumption of starter feed was greater in FAS than in FED calves. Total feed consumption 2 h after feeding was lower in NAL than in SAL calves. Calves in the FAS group did not discern between CF and SF during the first 4 h after feed offer. Preference for SF was greater in SAL than in NAL calves. Calves in the FED-SAL treatment preferred SF at 2 and 6 h after feed offer and tended to prefer SF at 4 h after feeding. However, FED-NAL calves did not discern between SF and CF during the first 4 h after feeding and tended to prefer SF only after 6 h from feeding. Plasma glucose, insulin, and cholecystokinin concentrations were greater in FED than in FAS calves. Injection of naloxone decreased plasma glucagon-like peptide-1 (GLP-1) in NAL calves. Blocking opioid receptors reduced intake the first 2 h after naloxone injection in FED calves, altered oro-sensorial preferences, and reduced plasma GLP-1 concentration. In conclusion, the opioid peptide system may control short-term feed intake by modulating the oro-sensorial response triggered by feed consumption, especially when calves are fed ad libitum., (Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Thirty-two crossbred lambs (BW = 31.2 ± 4.7 kg; 16 females, 16 males) housed in individual pens were used to investigate the relationship between nutrient supply and taste preferences in ruminants. Experiment 1 determined whether an imbalanced CP supply would alter preferences for feeds containing flavors designed to elicit either umami (U) or a mixture (1/3:1/3:1/3) of umami, sweet, and bitter (M) tastes. Lambs were randomly allocated to either a low (LP; 10.9% CP) or a high (HP; 20.4% CP) CP diet for 21 d. Afterward, lambs were presented during 21 d with a choice of the same LP or HP diet unflavored (LPC or HPC, respectively) or flavored (0.1% as fed) with U (LPU or HPU, respectively) or M (LPM or HPM). Experiment 2 determined the influence of CP status on preference for dietary CP, bitter taste, and sweet taste elicited by sucrose or a noncaloric sweetener. In test 1, sixteen lambs previously fed LP or HP for 42 d in Exp. 1 could choose between the HP and LP diets. In test 2, the remaining 16 lambs from Exp. 1 were offered a choice between unflavored LP or HP diets or the same diets flavored (0.066% as fed) with a bitter flavor. In test 3, the 16 lambs from test 1 were offered a choice between an unflavored diet (LP or HP) and the same diet flavored with sucrose (0.2%) or a noncaloric sweetener (0.066%). In Exp. 1, when offered a choice, all lambs showed a preference (P < 0.05) for the unflavored diet except for LP lambs, who clearly preferred (P < 0.05) LPU (72% of total DMI) over LPC. However, preference for LPU progressively decreased (P < 0.05) as time of exposure to the choice increased. In Exp. 2 (test 1), lambs previously fed LP progressively increased (P < 0.05) total DMI when presented with LP and HP, whereas consumption was constant for lambs previously fed HP and offered a choice of LP and HP diets. At the onset of test 2, lambs fed LP progressively reduced (P < 0.05) preference for the bitter flavor from 53 to 34%. In test 3, lambs previously fed LP diets consumed less (P < 0.05) sweetener- than sucrose-supplemented diet, whereas lambs previously offered HP diets consumed more sweetener- than sucrose-supplemented diet. In summary, protein-restricted lambs were able to differentiate and increase consumption of U-flavored feeds. However, this increase disappeared over time. These results indicate that lambs are able to sense dietary CP content and modulate short-term consumption of flavored feeds based on their nutrient requirements.

This study determined whether early experiences of sheep with the same feed, but presented in multiple or single flavors, would influence intake, the profile of hormones involved in feed intake regulation, and the subsequent acceptability of novel feeds. Thirty-five 2-mo-old lambs were randomly assigned to 5 treatments (7 lambs/treatment). Lambs in 1 treatment (the diversity treatment) were simultaneously fed an unflavored plain ration of alfalfa (control) and barley (75:25; as-fed basis) and the same ration mixed (0.2%) with 1 of 3 flavors: 1) sweet, 2) umami, or 3) bitter. The other 4 treatments (monotonous diets) received only 1 of the 4 rations. All animals were fed their respective rations from 0800 to 1600 h for 60 d. On d 55, intake was recorded every 30 min for 8 h. On d 58, blood samples from lambs were collected at 1 h prefeeding and at 30, 60, 210, 300, and 540 min postfeeding. Preference tests were conducted by simultaneously offering novel feeds: 1) high-energy feed, 2) high-protein feed, 3) beet pulp mixed with phytochemicals, or 4) low-quality feed. Lambs in the diversity treatment consumed more feed than did lambs in the other treatments (P < 0.001). Lambs in the diversity treatment consumed equivalent amounts of plain and umami feeds, with a greater amount (P < 0.001) of the umami feed being consumed than the bitter and sweet feeds. Lambs in the diversity treatment tended to grow faster than did lambs in the other treatments (P=0.06). On d 55, lambs in the diversity treatment showed decreased (P < 0.05) feed intake compared with lambs in the other treatments during the 2 peaks of food consumption (30 and 270 min from feeding) and showed a trend for the least plasma concentrations of ghrelin (P=0.06). In contrast, lambs in the diversity treatment consumed more feed than did lambs exposed to monotonous flavors at 60, 90, 120, and 180 min from feeding (P < 0.05). Lambs in the diversity treatment also showed the least concentrations of cholecystokinin and glucagon-like peptide 1 (P < 0.001). There were trends for the greatest concentrations of leptin (P=0.14) and IGF-1 (P=0.16) in the diversity treatment, and for the least concentration of leptin in the bitter treatment (P=0.14). Previous experience with flavored feeds affected the preference of lambs for high-energy and low-quality feeds, and for beet pulp mixed with phytochemicals (treatment × feed × day effect; P < 0.05). Thus, exposure to diverse flavors has the potential to increase feed intake and induce a more even consumption of feed across time by reducing peaks and nadirs of intake compared with exposure to monotonous rations. Flavor diversity may also influence the initial acceptability of and preference for novel feeds., (© 2011 American Society of Animal Science. All rights reserved.)