Blood Characteristics for High Altitude Adaptation in Tibetan Chickens

Abstract

Tibetan chickens, a unique chicken breed native to high altitude, have good adaptation to hypoxia. The experiment was conducted to determine the adaptive blood characteristics in Tibetan chickens. Fertile eggs from Tibetan and Dwarf Recessive White chickens were incubated, and the chicks were reared until 10 wk of age at low altitude (100 m) and high altitude (2,900 m). At 1 d and 2, 6, and 10 wk of age, the hematological characteristics, blood gas value, and blood volume were measured. Tibetan chickens had more red blood cells (RBC), smaller mean cell volume, lower pH and partial pressure of oxygen, and higher partial pressure of carbon dioxide at high altitude and had lower blood volume, erythrocyte volume, and plasma volume at low and high altitude than Dwarf Recessive White chickens. Tibetan chickens reared at high altitude retained a high level of RBC and a stable level of hematocrit from younger to older, but Dwarf Recessive White chickens reared at high altitude presented an increase in RBC and hematocrit values. It was concluded the adaptation was achieved in Tibetan chickens by increase in RBC and blood oxygen affinity, decrease in mean cell volume, and reducing susceptivity to hypocapnia.

Augmentation de la capacité photosynthétique avec l’altitude: mesures d’échanges gazeux à pressions partielles de CO2 ambiante et constante

“…Unfortunately, many studies have used CO 2 molar fractions instead of CO 2 partial pressure to express CO 2 availability, neglecting the fact that partial pressure decreases dramatically with elevation while molar fraction remains stable. As is the case for respiration in animals (Zhang et al, 2007), reduced partial pressure has a significant impact on gas exchange by plants; CO 2 assimilation closely depends on CO 2 partial pressure (P CO 2 ) and not CO 2 molar fraction (Farquhar et al, 1980). The decline in P CO 2 with elevation has led various authors to contend that the lack of CO 2 may be an important factor in the reduction of photosynthesis at high elevations (Decker, 1947;Tranquillini, 1964).…”

Effect of Altitudes on Blood Profiles of the Broilers

“…The lowland broilers have lower average erythrocytes when compared to the other lands. According to Zhang et al (2007), red blood cells (erythrocytes), hematocrit, and hemoglobin of broilers that live in the lowland (alt. 100 m) is tend to be lower than the highland.…”

“…Table 2 shows not much difference in hemoglobin average amount of the three altitudes, but the lowland tends to be lower than the others because of higher temperature in the lowlands and cause heat stress in broilers. According to Aengwanich and Chinrasri (2003), heat stress can decrease the amount of hemoglobin and the lowland broilers have lower amount of hemoglobin than those in the highland (Zhang et al, 2007). Low amount of hemoglobin is also…”

Síndrome de hipertensión pulmonar ¿un origen genético en pollos de engorde?

“…Investigaciones realizadas en pollos comerciales vs pollos criollos, en las que se midieron variaciones cardiopulmonares, valores de hemoglobina (Hb) y hematocrito en ambientes de hipoxia natural, los pollos nativos no presentaron susceptibilidad a desarrollar hipertensión pulmonar, como sí se presenta en la línea comercial (Moreno de Sandino y Hernández, 1985), lo que sugeriría que las estirpes sometidas a selección y mejoramiento genético serían presumiblemente más susceptibles a desarrollar el SHP (Pulido, 1996;Olkowski, 2007). Zhang et al (2007) explican que los pollos y mamíferos nativos de tierras altas poseen genotipos adaptados a grandes alturas, que fisiológicamente se caracterizan por alta afinidad hemoglobinaoxígeno, una respuesta moderada o nula a la policitemia, una baja presión parcial de oxígeno y una delgada pared vascular del árbol pulmonar, que se mantienen aun en tierras bajas y son transmitidos a su descendencia. Otra causa conocida de HAP en pollos es la exposición a bajas temperaturas (ejemplo 16 centígrados o menos) (Mejía, 1982;Pan et al, 2005).…”