Field curing methods and storage duration affect the quality of hay from six rangeland grass species in Kenya

Abstract

Introduction

Rangelands are important source of pasture for livestock in Kenya since time immemorial to pastoral households. However, seasonality on forage availability has been a big challenge in meeting animals’ feed requirements. This demands harvest and storage of pastures for use during dry seasons. Hay making has been done to bridge this forage deficit periods. However, hay quality in the rangelands is affected by curing methods, phonological stage at harvest, and the storage duration. We therefore evaluated the effect of field curing and storage duration on the quality (Crude Protein (CP)) of hay from six rangeland grasses in Kenya. Methods

The grasses evaluated are Chloris roxburghiana, Eragrostis superba, Enteropogon macrostachyus, Cenchrus ciliaris, Chloris gayana, and Sorghum sudanense. These grasses are the common species in the rangelands of Kenya and have been promoted in the past for hay making and reseeding interventions. The grasses were harvested at the mature flowering stage (12 weeks phenological stage), which is a period that provides high biomass without much effect on quality as practiced in the study area. The grasses were then cured in the field for 1, 2, and 3 days before baling and stored indoors for 12, 24, and 36 weeks. Samples were taken for CP content determination at the three periods following Macro-Kjeldahl Method. Results

There was significant decline (p ≤ 0.05) in crude protein content in all the grass species with storage periods. Curing period did not affect the CP content for all the species at a given storage period; however, 3 days curing changed the hay color from green to brownish which reduces palatability and consequently reduced feed intake. Storage period of over 12 weeks adversely lowered CP to less than 6 % for all the species which is the required minimum level for animal under production and maintenance. S. Sudanense had significantly higher decline in CP after 24 weeks storage compared to the other species. Conclusions

Therefore, hay from the six grass species harvested at mature flowering stage (12-week phonological stage) and stored longer than 12 weeks supplies the animals with low CP. Also, to maintain palatability, 1–2 days curing is recommended for the six grass species.