Growth performance, carcass and blood traits, immunity, jejunal morphology and meat quality of heat-stressed broiler chickens fed urea-treated pomegranate (Punica granatum L.) peel

Dietary supplementation with ellagic acid improves the growth performance, meat quality, and metabolomics profile of yellow-feathered broiler chickens

The aim of this research was to explore the effects of ellagic acid (EA) on growth performance, meat quality, and metabolomics profile of broiler chickens. 240 healthy yellow-feathered broilers were randomly divided into 4 groups (6 replicates/group and 10 broilers /replicate): 1) a standard diet (CON); 2) CON+0.01% EA; 3) CON+0.02% EA; 4) CON+0.04% EA. Compared with the CON group, dietary 0.02% EA increased linearly and quadratically the ADG and lowered F/G ratio from 29 to 56 d and from 1 to 56 d of age (P < 0.05). The EA groups had higher spleen index and showed linear and quadratic improve thymus index (P < 0.05). A total of 0.02% EA linearly and quadratically increased the leg muscle percentage and quadratically increased the breast muscle percentage (P < 0.05). Compared to the control diet, 0.02% EA decreased quadratically the L* and increased a* of breast muscle at 45 min postslaughter (P < 0.05), and quadratically decreased (P < 0.05) the b* and increased linearly and quadratically (P < 0.05) drip loss. Additionally, EA improved linearly and quadratically (P < 0.05) serum total protein concentration and reduced linearly and quadratically (P < 0.05) serum blood urea nitrogen concentration. A total of 0.02% EA quadratically increased catalase activity and decreased malondialdehyde concentration in breast muscle compared with the control diet (P < 0.05). 0.02% and 0.04% EA could linearly and quadratically increase (P < 0.05) the concentrations of histidine, leucine and essential amino acids (EAA), 0.02% EA could linearly and quadratically increase (P < 0.05) the concentrations of threonine, glutamate, and flavored amino acids in breast muscle. 0.02% EA linearly and quadratically improved the C20:3n6, C22:6n3, polyunsaturated fatty acid (PUFA) concentrations, and the ratio of PUFA to saturated fatty acids (SFA), but reduced the C16:0 and the SFA concentrations in breast muscle than the CON group (P < 0.05). The EA diet linearly increased (P = 0.035) and quadratically tended (P = 0.068) to regulate the C18:2n6c concentration of breast muscle. Metabolomics showed that alanine metabolism, aspartate and glutamate metabolism, arginine and proline metabolism, taurine and hypotaurine metabolism, and glycerophospholipid metabolism were the most differentially abundant. These results showed that EA supported moderate positive effects on growth performance, meat quality, and metabolomics profile of broilers.

Chromium Supplementation on the Growth Performance, Carcass Traits, Blood Constituents, and Immune Competence of Broiler Chickens Under Heat Stress: a Systematic Review and Dose-Response Meta-analysis

Several studies have been conducted to assess the effects of supplemental dietary chromium (Cr) on broiler chickens under heat stress (HS) conditions, but the shape and strength of the associations between Cr supplementation and broiler chickens' responses to HS remain unclear. Therefore, the current systematic review and meta-analysis investigated the effectiveness and dose-response relationship of Cr. The results indicated non-linear dose-response associations between Cr supplementation and body mass gain (BMG), feed intake (FI), feed conversion ratio (FCR), carcass, breast, leg, and abdominal fat relative weight (P_{non-linearity} < 0.05). The maximum BMG, FI, and the relative weight of carcass, breast, and leg would be achieved with 1200, 1100, 900, 800, and 800 ppb of Cr, respectively, while the lowest FCR and abdominal fat relative weight might be obtained with the supplementation of 1100 and 1000 ppb of Cr, compared with no Cr supplementation. Referring to BMG, supplementation with 1200-1700 ppb inorganic Cr or 2700 ppb or less organic Cr had a significant beneficial effect on the BMG, while NanoCr supplementation did not influence this outcome variable. A non-linear association was observed for blood total cholesterol concentration (TC, P_{non-linearity} < 0.05), with the maximum reduction of TC concentration observed at approximately 900 ppb of Cr. The cholesterol-lowering effect of Cr (≤ 2400 ppb) was only found in severe HS conditions. Moreover, supplemental Cr caused a significant linear reduction in the blood triglycerides and glucose concentrations (P < 0.05). The blood concentrations of triiodothyronine, thyroxine, and insulin increased linearly, and the corticosterone concentration reduced, with increasing supplemental Cr (P < 0.05). There was a non-linear inverse association between Cr supplementation and cortisol level (P_{non-linearity} < 0.05), and the lowest concentration of cortisol was observed with the supplementation of 1000 ppb of Cr. Meanwhile, significant positive linear associations between Cr supplementation and bursa percentage, thymus percentage, infectious bronchitis vaccine titer, avian influenza vaccine titer, Newcastle disease vaccine titer, cutaneous basophil hypersensitivity response, and serum immunoglobulin G level were found (P < 0.05). However, Cr supplementation caused a linear reduction in the heterophil/lymphocyte ratio (P < 0.05). Based on the obtained results, the recommended optimum amount of supplemental Cr is 1100 ppb.

Dietary supplementation of Solanum aethiopicum and Solanecio biafrae leaves alters stress and immune responses, antioxidant status, and meat quality in broilers raised in a hot-dry environment

1. This study investigated the influence of dietary supplementation of Solanum aethiopicum and Solanecio biafrae leaves, which have nutraceutical properties, on stress response, cytokine expression, antioxidant status, blood chemistry, abdominal fat and meat quality in broilers reared in a hot, dry environment.2. One day old, Ross 308 chicks (n = 350) were randomly allotted to basal diets containing either no supplement (D1); 2.5 g/kg Solanum aethiopicum leaf (SAL; D2); 5 g/kg SAL (D3); 2.5 g/kg Solanecio biafrae leaf (SBL; D4); or 5 g/kg SBL (D5) for 42 d. Birds were reared at 34 ± 2°C and 40-50% relative humidity for 6 h/d from 22-42 d. Each dietary group was replicated in seven pens containing 10 chicks.3. In the period 1-21 d, body weight gain, feed efficiency and feed intake were not influenced by diet. At 22-42 and 1-42 d, birds supplemented with SAL and SBL had higher (P < 0.05) body weight gain and feed efficiency than the D1 birds. Cloaca temperature, carcase cuts and relative organ weight did not differ between diets. The D3 birds had higher (P < 0.05) erythrocytes and haemoglobin compared with other birds. Dietary supplements reduced (P < 0.05) mortality, abdominal fat, serum total cholesterol, corticosterone, glucose and blood aspartate aminotransferase levels.4. The treatments up-regulated (P < 0.05) splenic intelukin-10, and down-regulated (P < 0.05) tumour necrosis factor-α and interleukin-1β genes. A dose-dependent improvement (P < 0.05) in antioxidant enzyme activities and total antioxidant capacity of serum and breast muscle were found in the supplemented birds. The breast meat of the supplemented birds had lower (P < 0.05) carbonyl and malondialdehyde contents, and higher (P < 0.05) water holding capacity and redness compared with the non-supplemented meat.5. These results illustrated that supplementation with either 5 g/kg SAL or 5 g/kg SBL attenuated the deleterious effects of heat stress in broiler chickens.