Effects of Spirulina (Arthrospira platensis) as a drinking water supplement during cyclical chronic heat stress on broiler chickens: Assessing algal composition, production, stress, health and immune-biochemical indices.

Spirulina, the blue green algae is considered to exhibit multifaceted benefits on both human health and animal production. Three hundred sixty day old unsexed broiler chicks of CARIBROVISHAL strain were assigned to five treatment groups each comprising nine replicates of 8 chicks. The experiment was carried out during the hot humid summer season (Mid-April to May) under deep litter rearing system with uniform managemental conditions. Birds were administered orally with Spirulina through drinking water in the morning (06:00-12:00 PM) on daily basis throughout the experimental period at 5, 10, 15 and 20 gL-1 concentration. Spirulina supplementation neither improved nor compromised production performance of broilers reared during hot climatic condition. Results based on one way analysis of variance indicated a significant effect on haemoglobin and total red blood cell count. Serum lipid content and transaminases were reduced, while serum protein concentration was higher (P < 0.01) in the groups administered with 15 and 20 gL-1 of Spirulina. The extent of imparting shank pigmentation was improved in all the supplemented groups. Cell mediated and humoral immunity against Phytoheamagglutunin-P and Newcastle disease vaccination respectively were maximized (P < 0.05) at 20 gL-1. These findings provide direct evidence of dose-related modulation of production, physiological and immunological attributes by Spirulina engendering its further investigation as a potential source of drinking water supplement for stress alleviation in broilers. From the results, it may concluded that Spirulina can be incorporated at 15 or 20 gL-1 for achieving optimal improvement of health and welfare attributes in broilers reared during hot summer without compromising production.

Impact of heat stress on broilers with varying body weights: Elucidating their interactive role through physiological signatures.

Physiological determinants of different body weight (BW) broiler chickens under heat stressed conditions were investigated to compare the performance at market age considering medium body weight group as standard. At 5 weeks, broilers were categorized randomly into 3 treatments (N = 24 per group) as high (HBW) (>1050 g), medium (MBW) (900-1050 g) and low (LBW) (<900 g) followed by simultaneous exposure to normal and heat stress (HS) conditions at 40 ± 1 °C and 45 ± 5% RH for 4 h/day for a period of 7 days (D) and sample collection was employed at D0, D3 and D7. Physiological and stress responses, haematological and biochemical profile, intestinal gross and histological aspects were estimated using standard protocols. Heart rate and mean arterial blood pressure were significantly (P = 0.000) higher in HBW broilers followed by low and medium ones. Heat stress exposure indicated significant (P = 0.000) increase in heart rate, arterial blood pressure, respiration rate and comb temperature while cloacal temperature remained unaffected. Lymphocytes, eosinophils, total red blood cell count, haemoglobin, and haematocrit were reduced (P = 0.000) whereas mean corpuscular volume and mean corpuscular hemoglobin, heterophil count and heterophil to lymphocyte ratio were increased (P = 0.000) in response to HS. Circulating corticosterone and tri-iodothyronine concentrations showed inverse relationship with respect to BW variation and HS duration respectively with significant interaction (P = 0.000). Higher protein in LBW was observed on D3. Serum triglycerides remained unaffected till D3 exposure but significantly (P = 0.017) reduced on D7 with lowest content in HBW group. Serum alkaline phosphatase increased in LBW group with significant heat stress interaction (P = 0.000) on D3. HS reduced villi length and crypt depth; but their corresponding ratio increased. In conclusion, HBW broilers are more affected than MBW or LBW groups. This study established interactive roles of BW and HS on physiological responses in broilers.

Use of Licorice (Glycyrrhiza glabra) Herb as a Feed Additive in Poultry: Current Knowledge and Prospects.

Supplementation of livestock and poultry diets with herbal plants containing bioactive components have shown promising reports as natural feed supplements. These additives are able to promote growth performance and improve feed efficiency, nutrient digestion, antioxidant status, immunological indices, and poultry health. Several studies have used complex herbal formulas with the partial inclusion of licorice. However, the individual use of licorice has been rarely reported. The major problem of the poultry industry is the epidemiological diseases, mainly confined to the respiratory, digestive, and immune systems. Licorice has certain bioactive components such as flavonoids and glycyrrhizin. The roots of this herb contain 1 to 9% glycyrrhizin, which has many pharmacological properties such as antioxidant, antiviral, anti-infective and anti-inflammatory properties. Licorice extracts (LE) have a positive effect on the treatment of high-prevalence diseases such as the immune system, liver, and lung diseases. Studies showed that adding LE to drinking water (0.1, 0.2, or 0.3 g/L) reduced serum total cholesterol (p < 0.05) of broiler chickens. Moreover, LE supplementation in poultry diets plays a significant role in their productive performance by enhancing organ development and stimulating digestion and appetite. Along with its growth-promoting effects, licorice has detoxifying, antioxidant, antimicrobial, anti-inflammatory, and other health benefits in poultry. This review describes the beneficial applications and recent aspects of the Glycyrrhiza glabra (licorice) herb, including its chemical composition and role in safeguarding poultry health.