Effect of dietary l-carnitine supplementation and energy level on oxidant/antioxidant balance in laying hens subjected to high stocking density

Potential for the development of Taraxacum mongolicum aqueous extract as a phytogenic feed additive for poultry

Introduction

Taraxacum mongolicum (TM) is a kind of medicinal and edible homologous plant which is included in the catalogue of feed raw materials in China. It is rich in polyphenols, flavonoids, polysaccharides and other active substances, and shows many benefits to livestock, poultry and aquatic products. The study aimed to assess the potential of TM aqueous extract (TMAE) as a substitute for poultry AGPs.

Methods

A total of 240 one-day-old Arbor Acker broilers were randomly assigned to four groups and fed a basal diet (Con) supplemented with 500, 1000, and 2000 mg/kg TMAE (Low, Medium, and High groups). The growth performance of the broilers was measured on day 21 and day 42. At the end of the trial, the researchers measured slaughter performance and collected serum, liver, spleen, ileum, and intestinal contents to investigate the effects of TMAE on serum biochemistry, antioxidant capacity, immune function, organ coefficient, intestinal morphology, flora composition, and short-chain fatty acids (SCFAs).

Results

The results showed that broilers treated with TMAE had a significantly higher average daily gain from 22 to 42 days old compared to the Con group. Various doses of TMAE resulted in different levels of improvement in serum chemistry. High doses increased serum alkaline phosphatase and decreased creatinine. TMAE also increased the antioxidant capacity of serum, liver, and ileum in broilers. Additionally, middle and high doses of TMAE enhanced the innate immune function of the liver (IL-10) and ileum (Occludin) in broilers. Compared to the control group, the TMAE treatment group exhibited an increase in the ratio of villi length to villi crypt in the duodenum. TMAE increased the abundance of beneficial bacteria, such as Alistipes and Lactobacillus, while reducing the accumulation of harmful bacteria, such as Colidextracter and Sellimonas. The cecum's SCFAs content increased with a medium dose of TMAE. Supplementing broiler diets with TMAE at varying doses enhanced growth performance and overall health. The most significant benefits were observed at a dose of 1000 mg/kg, including improved serum biochemical parameters, intestinal morphology, antioxidant capacity of the liver and ileum, immune function of the liver and ileum, and increased SCFAs content. Lactobacillus aviarius, norank_f_norank_o__Clostridia_UCG-014, and Flavonifractor are potentially dominant members of the intestinal microflora.

Conclusion

In conclusion, TMAE is a promising poultry feed additive and 1000 mg/kg is an effective reference dose.

Synthetic and phytogenic antioxidants improve productive performance, antioxidant activity, gene expression, and offspring quality in breeder hens subjected to heat stress

This study aimed to investigate the efficacy of a synthetic source (a combination of vitamin E, vitamin C, selenium, and L-carnitine) and phytogenic sources (a combination of clove, green tea pomace, and Vietnamese coriander) in overcoming heat stress (HS) damage in female breeder hens on production, blood chemistry, sperm survival in the oviduct, antioxidant properties, gene expression, and quality of offspring. One hundred SUT female breeder hens were housed in individual cages and divided into 4 treatment groups: T1) basal diets in the thermoneutral (TN) zone; T2) basal diets under HS; 3) basal diets with synthetic antioxidants under HS; and T4) basal diets with phytochemical antioxidants under HS. The result revealed that HS condition had a negative effect on reducing final body weight, egg weight, and 1-day-old chick weight while increasing water intake and FCR and altered blood chemicals in breeder hens compared to TN breeder hens (P < 0.05). However, either synthetic or phytogenic antioxidants resulted in increased egg production and hatchability, while decreasing the number of late stages of embryo death during the incubation (P < 0.05). Furthermore, the synthetic antioxidants also improved the uniformity of chicks and reduced late-stage embryo death compared with phytogenic antioxidants (P < 0.05). HS breeder hens fed with either of the antioxidant sources exhibited higher antioxidant capacity in terms of DPPH and ABTS radical scavenging (in yolk, liver, and breast meat) and FRAP radical scavenging (in yolk and liver) and lower liver malondialdehyde than HS breeder hens fed with the control diet (P < 0.05). Additionally, the gene expression of antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) in the liver was upregulated, whereas the expression of proinflammatory cytokines (nuclear factor-κB) and heat shock proteins (HSP70 and HSP90) was downregulated in breeder hens that received both antioxidant sources (P < 0.05). Future investigations should focus on the potential for combinations of synthetic and phytogenic antioxidants in diets for HS breeder hens.

Chromium propionate supplementation to energy- and protein-reduced diets reduces feed consumption but improves feed conversion ratio of yellow-feathered male broilers in the early period and improves meat quality

Growth performance and carcass traits may be retarded by low nutrient density diets. Organic chromium propionate (CrProp) can improve growth, carcass traits, and meat quality in farmed lambs, white broilers, and fish. Limited data regarding CrProp's impacts on yellow-feathered broilers are available. Eight hundred yellow-feathered male broilers (1-day old) were randomly allocated to 4 dietary groups and reared for 56 d. The trial was a 2 (dietary nutrient density) ×2 (CrProp) factorial arrangement with 4 diets: regular nutrient diet and low nutrient density (LND, reduction in metabolizable energy by 81 kcal and crude protein by 0.43%) diet supplemented with or without 200 mg/kg CrProp. Broilers were euthanized at d 56 after blood collection. The results indicated that the LND diet led to greater average daily feed intake (ADFI) from d 1 to 42 and feed conversion ratio (FCR) from d 22 to 42 (P < 0.05). Supplementation of CrProp improved body weight (BW) from d 1 to 56, average daily gain (ADG), and FCR during d 1 to 42 but reduced ADFI during d 1 to 21, as well as lowered abdominal fat percentage (P < 0.05). Supplementation with CrProp to regular and LND diets reduced ADFI but improved FCR from d 1 to 21 (P < 0.05). The LND diet lowered total antioxidant capacity (T-AOC) concentration and total superoxide dismutase (T-SOD) activity in the jejunal mucosa. CrProp elevated T-AOC levels and glutathione peroxidase activity (GSH-Px, P < 0.05). Dietary CrProp upregulated (P < 0.05) the expression of fatty acid transporter (FABP1) gene and peptide transporter (Pept1) gene. CrProp administration increased jejunal FABP1 expression and lowered cooking loss of breast meat (P < 0.05) in the LND group while reducing shear force (P = 0.009) of broilers treated by regular diet. In summary, CrProp administration to the LND diet can improve growth performance in the starter period and meat quality on d 56, possibly through upregulated nutrient transporter gene expression in the jejunum and enhanced antioxidant capability.

The antioxidative influence of dietary creatine monohydrate and L-carnitine on laying performance, egg quality, ileal microbiota, blood biochemistry, and redox status of stressed laying quails

The experiment was implemented to assess the influence of dietary supplementation of laying quails with creatine monohydrate (CrM), L-carnitine (CAR) and their mixture (CrMCAR) as antioxidants against oxidative stress (OS) induced by 2.5 ppm lead acetate (LA) in drinking water on productive, physiological and microbial aspects. In total, 400 laying quail females at 10 wk of age were divided into a randomized design with 5 groups and 4 replicates of 20 birds each. Birds were fed ad libitum with a balanced diet for 8 wk. The control group was kept under no-stress conditions and was given fresh water without any additives (G1). While birds in other groups were exposed to OS induced experimentally by 2.5 ppm LA in drinking water with no feed additive (G2) or supplemented with 500 mg/kg CrM (G3) or 500 mg/kg CAR (G4) or combination of 250 mg/kg each of CrM and CAR (CrMCAR, G5) to feed mixture. Compared to G2, G5 demonstrated the reduction (P ≤ 0.05) of feed conversion ratio, feed intake, mortality and ileal total coliform, as well as serum and egg malondialdehyde and serum lipid hydroperoxide, uric acid, glucose, cholesterol, enzymatic activities (alanine aminotransferase, aspartate transaminase, alkaline phosphatase, creatine phosphokinase, γ-glutamyl transferase), and heterophils/lymphocytes ratio. In the meanwhile, there was an increase (P ≤ 0.05) in egg production, egg mass, and weight with the improvement of egg quality, serum sex hormones level and ileal lactic acid bacteria for G5 followed by G4 and G3. Moreover, G5 enhanced (P ≤ 0.05), the total antioxidant capacity of egg and serum glutathione, superoxide dismutase, catalase, glutathione peroxidase, protein and calcium levels. Therefore, dietary CrMCAR, CAR and CrM have analogous influence to control by improving the antioxidant and physiological parameters which resulted in better productive performance and egg characteristics of stressed quails. These antioxidants, especially in their equal combination, are beneficial to alleviate oxidative stress incidence and can be recommended for poultry feeding under various aspects of environmental stresses.

The effects of L-carnitine-loaded solid lipid nanoparticles on performance, antioxidant parameters, and expression of genes associated with cholesterol metabolism in laying hens

The purpose of this study was to investigate the production performance, antioxidant parameters, egg yolk cholesterol content, and expression of genes related to cholesterol metabolism in laying hens fed L-carnitine (LC) and L-carnitine-loaded solid lipid nanoparticles (LC-SLNs). A total of 350 Hy-Line (w-36) laying hens at 50 wk of age (1520.0 ± 0.7 g) were randomly assigned to 35 units (5 replicates and 50 hens in each treatment) with seven dietary treatments as a completely randomized design. The dietary treatments were corn-soybean meal-based diets, including 1) Control (basal diet); 2) Basal diet +50 mg/kg LC (50LC); 3) Basal diet +100 mg/kg LC (100LC); 4) Basal diet +150 mg/kg LC (150LC); 5) Basal diet +50 mg/kg LC-SLNs (50LC-SLNs); 6) Basal diet +100 mg/kg LC-SLNs (100LC-SLNs) and 7) Basal diet +150 mg/kg LC-SLNs (150LC-SLNs). Results showed that the 50LC-SLNs had the least feed conversion ratio (FCR) in all groups (P < 0.05). The dietary supplementation of 100LC-SLNs decreased (P < 0.01) the egg yolk cholesterol concentration from 14.71 to 11.76 mg/g yolk (25%). The 50LC-SLNs group produced the most total antioxidant capacity with a difference of 58.44% compared to the control group (P < 0.01). The greatest amount of total superoxide dismutase was found for 50LC-SLNs (P < 0.05), while the glutathione peroxidase was not affected by the experimental treatments (P > 0.05). Serum malondialdehyde levels were reduced by 50.52% in laying hens fed 50LC-SLNs compared to the control group (P < 0.05). The transcript level of 3-hydroxy-3-methylglutaryl coenzyme A reductase was significantly decreased (P < 0.01) in the LC and LC-SLNs groups. The expression of cholesterol 7α-hydroxylase was significantly increased (P < 0.01) in the plain LC (∼83%) and LC-SLNs (∼91%) groups. The inclusion of LC-SLNs in the diet increased (P < 0.05) the villus height and decreased villus width in all three parts of the small intestine. Dietary inclusion of LC was found to reduce egg yolk and serum cholesterol content by improving the production performance and antioxidant status. The LC-SLNs groups were more affected than the plain LC groups, which may be attributed to the increased bioavailability of LC.

Peripartal Rumen-Protected L-Carnitine Manipulates the Productive and Blood Metabolic Responses in High-Producing Holstein Dairy Cows

This study aimed to monitor the effect of including rumen-protected L-carnitine (Carneon 20 Rumin-Pro, Kaesler Nutrition GmbH, Cuxhaven, Germany) in the transition diet on the productive and metabolic responses of multiparous high-producing Holstein dairy cows. Thirty-two multiparous cows were allocated in a completely randomized design to receive the same diet plus 60 g fat prill containing 85% palmitic acid (control, n = 16) or 100 g rumen-protected L-carnitine (RLC, n = 16); at 28 days before expected calving until 28 days in milk (DIM). Fat prill was included in the control diet to balance the palmitic acid content of both experimental diets. Milk production over the 28 DIM for the control and RLC groups was 46.5 and 47.7 kg, respectively. Milk fat content tended to increase upon rumen-protected L-carnitine inclusion (p = 0.1). Cows fed rumen-protected L-carnitine had higher fat- and energy-corrected milk compared with the control group. Pre- and post-partum administration of L-carnitine decreased both high- and low-density lipoprotein concentrations in peripheral blood of post-partum cows. The results of this study indicated that the concentration of triglycerides and beta-hydroxybutyrate was not significantly different between the groups, whereas the blood non-esterified fatty acid concentration was markedly decreased in cows supplemented with L-carnitine. Animals in the RLC group had a significant (p < 0.05) lower blood haptoglobin concentration at 7 and 14 DIM than the control. Animals in the RLC group had a lower concentration of blood enzymes than those of the control group. The mRNA abundance of Toll-like receptors 4, cluster of differentiation 14, and myeloid differential protein 2 did not significantly change upon the supplementation of L-carnitine in the transition diet. In summary, the dietary inclusion of RLC improved dairy cow's performance during the early lactation period. Greater production, at least in part, is driven by improved energy utilization efficiency and enhanced metabolic status in animals during the periparturient period.

Effect of dietary folic acid and energy density on immune response, gut morphology, and oxidative status in blood and breast muscle of broiler chickens

Folic acid (FA) plays essential roles in many metabolic functions and has been reported to have antioxidant effects. Therefore, dietary supplementation with high levels of FA may improve gut health and prevent potential oxidative stress caused by feeding a high energy density diet to broiler chickens. Broiler chickens were assigned into eight treatments, consisting of either a normal energy (NE) or high energy (HE) density diet, and four FA levels (2.2, 5, 10, and 15 ppm). Data were analyzed by SAS 16 GLM procedure. Birds-fed HE diets had increased (P < 0.05) plasma concentrations of calcium and albumin but reduced (P < 0.005) weights of ceca and bursa compared with those fed NE diets. Dietary supplementation with 10 ppm FA significantly increased (P < 0.05) birds’ heart weight and bile acid concentration. Folic acid and energy density interactions were significant for jejunal villus height (VH; P = 0.0226), villus width (VW; P < 0.0001), and crypt depth (CD; P = 0.0332). Among the NE group, birds fed 5–15 ppm FA had reduced (P < .0001) VW, while in the HE groups, 15 ppm FA supplementation resulted in an increased jejunal VH (P = 0.0317) compared with other treatments. In conclusion, dietary supplementation with increased levels of FA in HE diets could be beneficial for the intestinal health of broiler chickens.

Daily oxygen supplementation to the incubator at different stages of embryonic development alters the activity of antioxidant enzymes in the lung tissue of broiler chicks at a high altitude

1. Pulmonary hypertension, associated with mitochondrial function in the lung tissue of broilers, can occur at hypoxic high altitudes. The present research examined the impacts of O₂ supplementation at different embryonic stages on broiler organ development and antioxidant enzyme activities.2. In total, 360 eggs from Ross 308 broiler breeders at sea level were divided into a control group (O₂ non-supplementation group) and three experimental groups daily 1 h 23.5% O₂ supplementation from days 0 to 11 (O_0-11), from days 12 to 21 (O_12-21), and from days 18 to 21 (O_18-21) of embryonic age.3. The lung, heart, right ventricular (RV), and left ventricular (LV) + septum of newly hatched and seven day old chicks from every group were dissected and weighed. Antioxidant enzyme activities were examined in their lung tissue.4. The lung weight did not change in any group. At hatching, the heart weight (g and %) was higher in the O_12-21 and O_18-21 groups than in the O_0-11 and control groups, but the relative heart weight was the highest in the O_18-21 group in comparison with the O_12-21 group.5. Superoxide dismutase (SOD) activity increased in all experimental groups at both ages, but glutathione peroxidase (GPx) activity increased only in seven day old chicks. Catalase (CAT) exhibited high activity in the O_12-21 and O_18-21 groups at hatching. In the seven day old chicks, while the CAT activity did not change in the O_18-21 group, it decreased in the O_0-11 group and increased in the O_12-21 group.6. Glutathione reductase (GR) activity did not change in the O_18-21 group, but GR exhibited low activity in the O_0-11 group and high activity in the O_18-21 group in newly hatched chicks. The GR activity only decreased in the O_18-21 group of seven day old chicks.7. The results indicated that oxygen supplementation to the incubator caused alterations in the antioxidant enzyme activities in the lungs of broiler chicks, and this may have been in response to oxidative stress.