Orally Administered Ovine Serum Immunoglobulins Influence Growth Performance, Organ Weights, and Gut Morphology in Growing Rats

Abstract

In this study, our aim was to determine whether orally administered ovine serum Ig improved growth performance, organ weights, and gut morphology in growing rats and whether the method of manufacture of ovine serum Ig affected its bioactivity. Ninety Sprague-Dawley male rats were used in a 21-d growth study and were fed a basal control diet (BD; no Ig) and 5 test diets: spray-dried porcine plasma (SDPP), freeze-dried ovine Ig (FDOI), 2 concentrations of spray-dried ovine Ig (SDOI(100) and SDOI(150)), and inactivated ovine Ig (IOI). Diets were isocaloric and contained the same amount of the first limiting amino acids, methionine plus cysteine. The body weight gain:feed ratio was higher (P < 0.05) for the FDOI-fed rats than for the BD- and IOI-fed groups. FDOI rats had higher jejunum (P < 0.05) and colon weights (P < 0.05) at the end of the study than rats in the BD group. Compared with the SDOI(100)-fed group, the FDOI group supported higher (P < 0.05) duodenum and colon weights. For gut morphology, the FDOI and the BD and IOI groups differed (P < 0.05). The FDOI-fed rats had longer (P < 0.05) villi and greater villi surface areas in the duodenum, jejunum, and ileum than the rats fed SDOI(100). An ovine Ig fraction selectively improved growth performance, organ weight, and gut morphology in growing rats. Compared with spray-drying, a freeze-drying procedure appears to preserve a higher degree of immunological activity.

Dietary supplementation with ovine serum immunoglobulin attenuates acute effects on growth, organ weights, gut morphology and intestinal mucin production in the growing rat challenged with Salmonella enteritidis

“…Preparation and quantitation of ovine serum immunoglobulin FDOI and inactivated ovine Ig (IOI) were prepared as described by Balan et al (2009). Briefly, ovine Ig was precipitated from fresh lamb's blood using ammonium sulphate and the resulting precipitate freeze-dried.…”

“…The IgG content in the ovine Ig fraction was determined in quadruplicate by direct ELISA using a rabbit anti-sheep IgG (AbD Serotec, Oxford, UK) as described by Balan et al (2009). The respective protein and Ig concentrations of the FDOI were 96.5% and 73.6%, whereas in the IOI they were 94.3% and 71.9%, respectively.…”

“…All diets exceeded the recommended nutrient requirement levels for the growing rat for all nutrients (National Research Council, NRC, 1995). The FDOI and IOI fractions were included in the respective diets at a concentration approximately equal to the amount of spray-dried porcine plasma (SDPP) IgG used in previous studies (Pierce et al, 2005;Balan et al, 2009 Values for nutrients were from chemical analysis except for carbohydrate that was calculated by difference using the formula (100 2 (moisture 1 ether extract 1 ash 1 CP) 5 carbohydrate).…”

“…From each tissue, transverse sections were cut, stained with haematoxylin, eosin and alcian blue and examined under a light microscope. The five longest and straightest villi and their associated crypts from each transverse tissue section were selected from 10 rats for each experimental treatment, and the villus height, crypt depth and villus surface area (VSA) for each section measured as described previously (Balan et al, 2009). Colon tissue samples were prepared as described for the small intestine samples and the crypt depths were measured for five elongated and straight crypts from each transverse tissue section selected from 10 rats for each experimental treatment.…”

“…Recently, our own group has reported that feeding freeze-dried ovine serum Ig (Ig extracted from lamb's blood) to normal growing rats improved growth performance, increased the weight of some digestive organs and improved the gut architecture (Balan et al, 2009). It also supported a higher degree of immunological activity , selectively altered the composition of the gut microbiota and modulated the transcription and translation levels of mucin in the GIT (Balan, 2010).…”