Changes in the Expression of MIF and Other Key Enzymes of Energy Metabolism in the Myocardia of Broiler Chickens with Ascites Syndrome

Mechanism of pulmonary arterial vascular cell dysfunction in pulmonary hypertension in broiler chickens

Broiler ascites syndrome is a common and complex disease in broiler farming, which severely impacts broiler growth performance and health and brings huge economic losses to the breeding industry. Hypoxia has been shown to be an important cause of this disease. Prolonged exposure of broiler chickens to a hypoxic environment induces pulmonary vasoconstriction, which leads to an increase in pulmonary artery pressure, triggering pulmonary artery remodelling and compensatory right ventricular hypertrophy, and ultimately ascites. Pulmonary artery remodelling is a process in which the vascular wall tissue structure and function undergo pathological changes after the pulmonary artery is stimulated by various injuries or hypoxia, including endothelial dysfunction, abnormal proliferation of pulmonary artery smooth muscle cells, vascular fibrosis, etc. When these cells are damaged or stimulated, they may undergo programmed cell death, an orderly and regulated mode of cell death that is important for maintaining the stability of the body's internal environment. It has been demonstrated that death modes such as apoptosis and autophagy are involved in the pathophysiologic process of pulmonary hypertension, but their specific molecular mechanisms are still unclear. In this review, we first describe the pathogenesis of broiler ascites, then describe the specific mechanism of dysfunction of pulmonary artery vascular cells in broiler ascites syndrome, and finally elaborate the progression of different programmed cell death in broiler pulmonary hypertension. This study aims to elucidate the specific mechanisms underlying the dysfunction of pulmonary artery vascular cells in broiler pulmonary hypertension, thereby enhancing our understanding of the pathogenesis of this syndrome.

Omega-3 fatty acids mitigate histological changes and modulate the expression of ACACA, PFK1 and ET-1 genes in broiler chickens under environmental stress: a pulmonary artery, cardiomyocyte and liver study

The aim of this study was to investigate the effects of omega-3 fatty acids on blood biochemical parameters, histological changes in pulmonary artery, cardiomyocytes, and liver, as well as the expression of ACACA, PFK1, and ET-1 genes in broiler chickens under environmental stress (high stoking density). A total of 420 one-day-old male Ross broilers were used in a 2 × 2 factorial arrangements, with 2 levels of environmental stress (without and with stress; 9 and 17 birds/m2, respectively) and 2 levels of omega-3 fatty acids (low and high; 0.057 and 0.5% of the diet, respectively) in a completely randomized design comprising 4 treatments and 5 replicates per each. The body weight decreased at d 40 because of environmental stress (P ≤ 0.05). The ascites heart index (AHI) in broilers fed high omega-3 fatty acids diets was lower (P = 0.062) than broiler fed low omega-3 fatty acids diet (0.279 vs. 0.316). Stressed birds showed a higher neutrophil: lymphocyte ratio compared to non-stressed birds (P ≤ 0.05). Broiler chickens receiving high omega-3 fatty acids diets exhibited elevated levels of hematocrit (HCT), hemoglobin (HGB), and lymphocytes (P ≤ 0.05). The neutrophil: lymphocyte ratio, and serum concentration of alanine aminotransferase (ALT), and aspartate aminotransferase (AST) decreased in broilers fed high omega-3 fatty acids diets (P ≤ 0.05). In stressed broilers on a high omega-3 diet, pulmonary artery wall thickness decreased (P ≤ 0.05). Additionally, under stress, myocardial cell diameter, hepatocyte and cell nucleus diameter significantly increased (P ≤ 0.05). Stressed broilers showed an increased relative fold change in PFK1 enzyme activity but reduced ET-1 mRNA expression in the liver compared to stressed birds on a high omega-3 diet (P ≤0.05). In conclusion, the results indicate that dietary omega-3 fatty acids have the potential to alleviate the adverse histological changes in the pulmonary artery, cardiomyocytes, and liver, while also modulating the expression of genes ACACA, PFK1, and ET-1 that are influenced by environmental stress in broiler chickens.

Effects of Different Photoperiods on Growth Performance, Glucose Metabolism, Acetylcholine, and Its Relative Acetylcholine Receptor Modulation in Broiler Chickens

Photoperiods are crucial environmental factors in the growth and health of modern intensive broiler chicken production. To date, the effects of different photoperiods on glucose metabolism, acetylcholine (ACh), and its relative acetylcholine receptor modulation in broilers remain elusive. Herein, we aimed to identify the effects of different photoperiods on regulating glucose metabolism, ACh, nicotinic acetylcholine receptor alpha 4 (α4 nAChR) mRNA, and M3 muscarinic acetylcholine receptor (M3 mAChR) modulation in broilers. A total of 216 healthy 5-day-old Arbor Acres (AA) male broilers was randomly assigned to 12L:12D, 18L:6D, and 24L:0D photoperiods for 4 weeks. The results show that, compared with the 12L:12D photoperiod, the 18L:6D and 24L:0D photoperiods significantly increase the average daily gain (ADG) and average daily feed intake (ADFI) of broilers (p < 0.05). However, the feed efficiency (FE) of broilers significantly decreased in the 18L:6D and 24L:0D photoperiods (p < 0.05). Moreover, compared with the 12L:12D photoperiod, the ACh concentrations and α4 nAChR mRNA expression levels in the hypothalamus and medulla oblongata of broilers significantly increased (p < 0.05); M3 mAChR mRNA expression levels in cecum significantly reduced in the 18L:6D photoperiod and the 24L:0D photoperiod (p < 0.05). Compared with the 12L:12D photoperiod, the serum glucose (GLU), serum insulin (INS), serum triglyceride (TG) levels, and homeostasis model assessment of insulin resistance (HOMA-IR) of broilers significantly enhanced in the 18L:6D and 24L:0D photoperiods (p < 0.05). Our results indicate that extending the photoperiod can promote the growth rate, ACh expression, and α4 nAChR mRNA expression of broilers while reducing the feed efficiency, inhibiting M3 mAChR mRNA expression, and inducing glucose metabolism disorders in broilers.

Different fat-to-fiber ratios by changing wheat inclusion level impact energy metabolism and microbial structure of broilers

Introduction

Dietary nutrient content is crucial for energy metabolism and development of gut microbiota. Herein, this study aimed to explore the effects of fat-to-fiber ratios on nutrient transporter, energy metabolism and gut microbiota when ingredients composition was altered.

Methods

A total of 240 as-hatched broiler chickens were randomly assigned into three groups including low fat-high dietary fiber (LF-HD), medium fat-medium dietary fiber (MF-MD) and high fat-low dietary fiber (HF-LD), with diets being iso-protein, and broilers were offered the same commercial diets from 21 to 42 d. The data were analyzed using one-way ANOVA of SPSS.

Results and Discussion

Results showed that HF-LD diet significantly increased glucose content and decreased triglyceride in serum of broilers (p < 0.05). The mRNA abundance of jejunal gene involved in glucose transporter and tricarboxylic acid (TCA) cycle was significantly increased in broilers fed with HF-LD diets. Compared with LF-HD, HF-LD had a lower abundance of Anaerofilum and CHKCI001, and an increased proportion of beneficial bacteria such as Alistipes, Catenibacillus, Intestinimonas, Lactobacillus, and Peptococcus (p < 0.05). Functional prediction of these microbial changes indicated that HF-LD diet drove caecal microbiota to participate in carbohydrate metabolism and TCA cycle (p < 0.05). Dietary HF-LD-induced microbiota changes were positively correlated with growth performance of broilers (p < 0.05). Therefore, HF-LD diet increased glucose transporters and energy metabolism in intestine and shaped microbial structure and metabolic pathways, which may benefit the growth performance of broilers.