Guar meal germ and hull fractions differently affect growth performance and intestinal viscosity of broiler chickens

Abstract

High concentrations of guar meal in poultry diets deleteriously affect growth, feed intake, and digesta viscosity. These effects are attributed to residual gum in the meal. A 2 x 5 factorial experiment investigated the impacts of two guar meal fractions (germ and hull) at five inclusion levels (0, 2.5, 5.0, 7.5, and 10.0%) on intestinal viscosity, measures of growth, and feed conversion in broiler chickens fed to 20 d of age. Growth and feed conversion ratio were not affected by inclusion of as much as 7.5% of the germ fraction into poultry diets, while inclusion of the hull fraction reduced growth at all concentrations. The hull fraction increased intestinal viscosity at all inclusion levels fed, although feed conversion was not affected until the inclusion rate exceeded 5.0%. The germ fraction significantly increased intestinal viscosity at 7.5 and 10% inclusion rates. When germ fraction was fed, relative organ weights remained constant through all concentrations except for the ventriculus and duodenum at 7.5 and 10% inclusion levels. Relative pancreas weight was significantly increased at the 10% level of the hull fraction. Increases in intestinal viscosity corresponded with growth depression. These results suggest that residual gum was responsible for some deleterious effects seen when guar meal was fed. The germ fraction was a superior ingredient when compared with the hull fraction. The guar meal germ fraction constituting as much as 7.5% of the diet supported growth and feed conversion measures similar to those observed with a typical corn-soybean poultry ration.

The Effects of Guar Meal on Production Performances in Broiler Chicken

“…Similar results were also reported by Lee et al (2003). They reported that guar meal, administered in doses of 2.5% and 5% in feeds, had no negative effects on the growth performances of broiler chickens, whereas higher doses (7.5 and 10%) negatively influenced both growth performances and broiler chicken health.…”

Effects of Dietary Inclusion of Guar Meal Supplemented by β-Mannanase on Performance of Laying Hens, Egg Quality Characteristics and Diacritical Counts of White Blood Cells

“…In the study by Lee et al (2003a), the hull fraction of gaur increased intestinal viscosity at all inclusion levels fed (0, 2.5, 5.0, 7.5 and 10.0%). In their investigation, although FCR was not affected until the inclusion rate exceeded 5.0%; whereas, the germ fraction significantly increased intestinal viscosity at 7.5 and 10% inclusion rates.…”

“…Some studies reported that there was no negative impact on productive performance after adding GM without enzyme to diets at concentrations up to 2.5% in broiler chicks (Lee et al, 2003a;2003b) or 5% in laying hen diets (Gutierrez et al, 2007). Different indigestible polysaccharides, such as pectin, gum Arabic, gum agar, locust bean gum and guar gum, increase intestinal viscosity, which decreases growth and increases feed conversion.…”

Practical Application of Guar (Cyamopsistetragonoloba L. Taub) Meal in Poultry Nutrition

“…However, guar bean contains some anti-nutritional factors like trypsin inhibitor and a galactomannan (guar gum) which affect feed conversion ratio and growth performance in broilers (Saxena and Pradhan, 1974). Diets supplemented with guar bean increases intestinal viscosity due to β-galactomannan leading to reduced nutrient digestibility especially in a day old chickens (Lee et al, 2003;Abu Hafsa et al, 2017). This increase in the intestinal viscosity has also a negative effect on passage rate resulting in poor feed intake (Yasar, 2003).…”