Distribution and developmental changes of IL-21 immunopositive cells in the bursa of Fabricius of Jinhu silky chicken.

Bursa of Fabricius (BOF) is a unique immune organ of birds. It is the place where lymphocytes develop, differentiate and mature. Young chicken BOF is susceptible to infection and damage, and even atrophy, causing immune suppression, and bringing huge economic losses to chicken production. Therefore, studying the regulatory mechanism of chicken bursa development is of great practical significance for disease prevention and diagnosis. Jinhu silky chicken (JSC) is a local excellent breed in the Fujian Province of China and with strong disease resistance. However, studies on the disease resistance of JSC are scarce. This study aimed to provide a theoretical basis for reproduction and disease control of JSC. Developmental features of the structure and the IL-21-positive cell (IL-21 PC) distribution on the BOF in JSC were measured from 7 to 300 days of age. Bursas of chicken (n = 36) were taken at 7, 35, 70, 150, 240, and 300 days of age for preparation of paraffin sections and stained with hematoxylin-eosin (HE) and immunohistochemistry. The microstructure of JSC's BOF was similar to that of other poultry. The cortical-medullary boundary of the bursa nodule was not obvious at 7 days of age, but it was evident after 35 days of age. Before 70 days of age, IL-21 positive cells (PC) were scattered on the BOF. At 150 days of age, the number of IL-21 PC in the bursa were the highest and the nuclei were clear. The level of IL-21 PC gradually decreased with age. The BOF degenerated and disappeared in 300-day-old JSC. The histological structure of the BOF was similar to that of other poultry. IL-21 PC were widespread in the BOF at different ages, but the numbers were different.

Serum electrolyte and mineral variations during pregnancy and lactation in Nili-Ravi buffalo.

The aim of present study was to determine the changes of sodium, potassium, chloride, copper, and zinc in serum of Nili-Ravi buffalo during pregnancy and lactation. The study was carried out on 25 Nili-Ravi buffaloes during March 2008 to February 2009 at Buffalo Research Institute, Pattoki, District Kasur. Blood samples were taken from each buffalo during early pregnancy (Phase EP), i.e., between 1 and 3 months gestation, mid pregnancy (Phase MP), i.e., between 4 and 6 months gestation, late pregnancy (Phase LP), i.e., between 7 and 10 months gestation, and during lactation (Phase LT). Serum sodium, potassium, and chloride were determined on a clinical chemistry analyzer whereas copper and zinc were determined on an atomic absorption spectrophotometer. The mean serum sodium, potassium, and chloride concentrations varied non-significantly (P > 0.05) during pregnancy and lactation. With advancing pregnancy, copper increased and was significantly high (P < 0.05) during late pregnancy whereas during lactation copper concentrations dropped significantly (P < 0.05). The zinc concentrations increased non-significantly during early and mid pregnancy. There were significant differences (P < 0.05) in zinc concentrations during lactation compared with late pregnancy. This study demonstrates that concentrations of serum sodium, potassium, and chloride remain unchanged during pregnancy and lactation whereas serum copper concentrations increased and zinc concentrations decreased with advancing pregnancy because of the demand of the fetus at different periods of pregnancy.