Relationship of retinoid and carotenoid metabolism with caecotrophy in rabbits.

Abstract

The relationship of retinoid and carotenoid metabolism with caecotrophy was studied in adult female New Zealand White rabbits kept in individual metabolic cages. Caecotrophy was prevented by the use of plastic collars. The dry matter, crude protein, fibre, fat and ash contents of hard and soft faecal samples were determined. The retinoid (retinol and retinyl palmitate) and carotenoid (canthaxanthin, β-carotene, β-cryptoxanthin, lutein and zeaxanthin) levels of the blood, liver, kidney, caecal content and faeces were also measured by high-performance liquid chromatography (HPLC). The prevention of caecotrophy resulted in a significant decrease of blood retinol (P < 0.001) and retinyl palmitate (P < 0.01) concentration but it did not cause any significant change in the retinol and retinyl palmitate contents of the liver and kidney. The caecal content (25.78 ± 6.87 µg/g) and the soft faeces (34.52 ± 10.48 µg/g) contained the retinoids in similar amounts. Various carotenoids were found in considerable amounts in different types of faeces, while in the tissues (blood, liver and kidney) these pigments did not occur in substantial amounts. Total carotenoid concentration was similar in the caecal content (11.23 µg/g) and in the caecotroph (13.85 µg/g). On the basis of the results it can be assumed that the retinoid content of rabbit feed could be lowered in the presence of adequate caecal function and caecotrophy.Key words: Retinoid, carotenoid, metabolism, caecotrophy, rabbit In the present day, retinoids (vitamin A) and provitamin A carotenoids are a major focus of research around the world owing to their cytoprotective, immunostimulating and antitumour effects. Retinoids are known to be involved in fetal development and in regulating the proliferation and differentiation of many cells and tissues throughout life. They are also essential for the maintenance of normal reproductive processes and immune response (Blomhoff et al., 1990).In the past decade the effects of high or low dietary vitamin A levels on growth and reproductive performance were investigated in rabbits. High

Impact of diet on faecal output and caecotroph consumption in rabbits

“…, Kerti et al . ), and the higher protein and energy content of concentrates allows nutritional requirements to be met solely from the diet, resulting in increased numbers of uneaten caecotrophs. Other factors implicated in reduced caecotroph consumption include obesity, perineal dermatitis, dental and musculoskeletal diseases (Harcourt‐Brown ).…”

The Role of Nutrition in Immunity and Diseases Resistance in Rabbits

“…Β-Carotene is the major precursor of vitamin A that occurs naturally in feedstuffs. Research suggests that β-carotene may affect immune function, independent of its role as a source of vitamin A. β-Carotene, as such, can serve as an antioxidant, while vitamin A is not an important antioxidant (Kerti et al, 2005(.…”

Microbiome-Metabolome Analysis of the Immune Microenvironment of the Cecal Contents, Soft Feces, and Hard Feces of Hyplus Rabbits

“…Soft feces of rabbits contain a large number of bacterial proteins and nutrients. Eating soft feces can prolong the time of feed passing through the digestive tract, improve the digestion and absorption efficiency of feed, help to maintain the normal microbiota of the digestive tract, and alleviate nutritional diseases [ 13 , 14 ]. Preventing rabbits from eating their feces reduces the content of vitamin A in the blood, causes them to slowly lose weight, increases the content of acetic acid and propionic acid in the blood, reduces the content of butyric acid, and causes skin damage to the eyes and ears.…”