Effects of cage size on growth performance, blood biochemistry, and antibody response in layer breeder males during rearing stage.

This study was conducted to investigate the effects of cage size on growth performance, blood biochemistry, and antibody response in layer breeder males during rearing stage. 575 one-day-old Jinghong layer breeder males were randomly allocated into 3 treatments and reared in 3 cage sizes: large (160 × 160 × 62 cm; LC), medium (120 × 120 × 62 cm; MC), and small (80 × 70 × 62 cm; SC). The stocking density of birds in 3 treatments was kept identical and adjusted every 2 wk, from 45 birds/m2 during the period of 0 to 2 wk of age to 12 birds/m2 during the period of 17 to 18 wk of age. Body weight and shank length were measured every 2 wk, and then the daily weight gain and daily feed intake were calculated. Tibia length and breaking strength were determined at 8 wk of age. Blood parameters including malodiadehyde (MDA), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), alkaline phosphatase (ALP) and corticosterone (CORT), and antibody titers against avian influenza viruses H5N1 (Re-5 strain) and H9N2 (Re-2 strain) and Newcastle disease virus in response to vaccination were determined at 18 wk of age, respectively. Body weight, shank length, and daily weight gain of birds in LC were similar with those in MC, and were greater than those in SC at 18 wk of age (P < 0.05), respectively. No significant difference was found in average daily feed intake among the 3 treatments from 11 to 18 wk of age. Birds in LC and MC had the similar tibia length; however, birds in SC were smaller (P < 0.05). Tibia breaking strength of birds in LC was higher than those in SC (P < 0.05), respectively. Birds in LC showed lower plasma MDA, GSH-Px, SOD, and CORT contents than those in MC and SC (P < 0.05); however, birds in LC exhibited higher levels of serum antibody titers against H5N1 and H9N2 avian influenza viruses as compared with MC and SC (P < 0.05). Consequently, LC and MC were superior to SC and were beneficial for birds' growth and development.

Descriptive epidemiology of deployment-related medical conditions and shipboard training-related injuries in a Chinese Navy population.

OBJECTIVES: To investigate the deployment-related medical conditions and shipboard tactical training-related injuries in a Chinese Navy population. STUDY DESIGN: A retrospective study with the Chinese Navy was conducted. METHODS: The medical records of 1543 Navy crewmembers from 2011 to 2015 were collected. The distribution and incidence rate (IR) of different types of medical conditions were provided and compared between the Aden Gulf deployment and nondeployment periods. The occurrence of military training-related injuries in crewmembers receiving 12-week shipboard tactical training was compared with that of 956 marines and 4371 recruits receiving combat and physical training, respectively. The anatomic locations and types of training-related injury were analyzed. RESULTS: Compared with the nondeployment period, the percentages of the following injuries were significantly higher during deployment: injuries and certain other consequences of external causes (16.97% vs 7.76%), diseases of the musculoskeletal system and connective tissue (15.40% vs 10.34%) and mental and behavioral disorders (11.23% vs 3.45%); however, respiratory system diseases had a lower percentage (19.84% vs 28.35%). Far seas deployment significantly increased the IRs of acute upper respiratory infection, skin and eye infection, sprains and low back pain as well as aphthous ulcer, insomnia, and seasickness (P < 0.05, 0.01 or 0.001). Shipboard training induced higher IRs of injuries to the upper extremities, spine and back and head and face than physical training and a higher incidence of head and face injury than combat training (P < 0.05 or 0.001). Physical training had higher IRs of overuse injuries than shipboard and combat training (P < 0.001). The IR of fracture was higher during combat and physical training than shipboard training (P < 0.01 and 0.001). CONCLUSIONS: The Chinese Navy has experienced novel health issues in crewmembers in recent years. Corresponding countermeasures should be taken to address deployment-related medical conditions and shipboard training-related injuries in the future.