Effects of Dietary Inclusion of Seaweed, Heat Stress and Genetic Strain on Performance, Plasma Biochemical and Hematological Parameters in Laying Hens

Abstract

This study was planned to investigate the effects of seaweed supplementation, genetic strain, heat stress and their interactions on laying hen performances, blood chemistry and hematology. In a short-term trial, laying hens of the two genetic lines Lohman LSL-Lite (White) and Lohman Brown-Lite (Brown) were supplemented with Chondrus crispus (CC) at 3% for 21 days, while a control group was not. In a long-term trial, the same two strains were assigned to control (0%), 3% red seaweed Chondrus crispus (CC) or 0.5% brown seaweed Ascophyllum nodosum (AN)-supplemented diets for 41 weeks, concluding with a four-week control or heat-stress period. The White hens displayed higher egg production and a lower feed/egg ratio. The short-term inclusion of CC significantly reduced the feed intake, weight gain and feed/egg ratio. The long-term seaweed intake affected the plasma albumin and gamma-glutamyl transferase (GGT) (p < 0.05), and there were significant strain-heat stress interactions; heat stress in the Brown birds was associated with reduced protein, globulin and glucose and increased cholesterol and GGT levels and higher heterophil-to-lymphocyte (H/L) ratios (p < 0.05) in response to heat stress (p < 0.05). In conclusion, a long-term seaweed supplementation affected the plasma protein and enzyme profiles, yet had little effect on hen leukocyte counts and the overall performance.

Impact of Dietary or Drinking Water Ruminococcus sp. Supplementation and/or Heat Stress on Growth, Histopathology, and Bursal Gene Expression of Broilers

“…Meanwhile, the total leukocytic count and monocytes are significantly decreased, and this decrease was inconsistent with the present results. Moreover, thermal stress increases leukocytic count, heterophils, and the ratio between heterophils and lymphocytes in the brown birds ( 61 ). These adverse effects were improved by treatments, especially with enzymes and probiotic supplementation.…”

An Acute, Rather Than Progressive, Increase in Temperature-Humidity Index Has Severe Effects on Mortality in Laying Hens

“…A 2-h heat stress at 32 • C did not have a significant effect on plasma corticosterone, glucose, and uric acid in laying hens before and after the stress (35). However, a long-term heat stress for 16 weeks reduced plasma corticosterone small but significantly and this result was influenced by age (36). In a study in which 68week-old Lohmann Brown-Lite hens were exposed either to 25 • C as a control or to high ambient temperatures gradually rising from 25 • to 33 • C from 11:00 to 18:00 h for 28 days, Borzouie et al (37) showed that heat stress resulted in a significant reduction in plasma protein (24.3%) and globulin (33.1%) while significantly increasing cholesterol (164.3%), alanine aminotransferase (300%), and glutamate dehydrogenase (885.2%).…”

Environmental Enrichment as Part of the Improvement of the Welfare of Japanese Quails

“…Among the physiological indicators of stress are some elements of the blood plasma biochemical profile, as well as cortisol or corticosterone levels. Biochemical indicators like AST, ALT and LDH are most often analysed in the contexts of heat or oxidative stress [ 42 ], but other authors show that the disruption of the basic biochemical blood profile can also be influenced by the rearing system [ 43 ] or the enrichment of the birds’ environment [ 44 , 45 ].…”