Evaluating the nutritive value of sorghum Stover, with graded levels of Rhodes grass hay

Abstract

This study was conducted to assess the nutritive value of the sorghum Stover when mixed with a less fibrous Chloris gayana, which is also highly abundant in the Uganda. Dairy farmers often suffer from scarcity of the forage to feed their dairy animals especially in the dry seasons. Although there is normally abundant sorghum Stover after harvest during this same time, farmers hardly utilize this resource due its high fiber content at that stage of maturity affecting its palatability. This study was conducted at the National Livestock Resources Research Institute (NaLiRRI) to evaluate the nutritive value of sorghum Stover when mixed with graded levels of Rhodes grass hay. Samples of ground sorghum Stover to which Chloris hay was added at varying inclusion levels of 0%, 25%, 50%, 75% and 100% in a Completely Randomized Design and were analyzed for their proximate composition and were digested following the standard procedures of the In vitro gas production technique. Data obtained was analyzed using SAS analytical software and was used for estimating the nutritive value of the combinations in terms of energy, protein content, fat, fiber content, inorganic mineral levels and degradability of the dry matter. Results showed that the CP, EE and Ash content of the Stover were significantly (P<0.05) increased as more Chloris was added while the fiber content of the combination was decreased. Analyzing the samples for all nutritional parameters indicated that Sorghum Stover with 25% Chloris hay in combination was the most nutritious with high energy value (8.18 MJ/kgDM), the most degradable NDF (17.22%) and Organic matter (82.45%). The feed combination was also the most degradable amongst the SCCs and hence may be better utilized by the animals. The results of the study concluded that the nutritive value of the Stover and thus its utilization can be enhanced when Rhodes hay is added to it at 25% inclusion level. The study thus recommends that sorghum Stover may be used in a strategic basal diet in ruminant feeding such as critical classes of cattle, goats and other ruminants, particularly lactating female when other energy rich forages are scarce. Further studies may be done to determine the levels of intake of the combination for ruminants at other physiological states than lactating.