Palatability of multipurpose tree species: effect of species and length of study on intake and relative palatability by sheep

Abstract

The potential forage value and appropriate length of study on intake and relative palatability ranking of 40 multipurpose tree species (MPTs) were determined using 24 sheep blocked on live weight and age. As the MPTs had different dry matter contents, intakes were also expressed as a ratio of quantity offered (A/D3. Using daily Eragrostis tef straw offer (TD) and intake (T), relative palatability indices were calculated as R i = (A]DI)/(Ti/TDi).There was a significant (P < 0.0001) decrease in correlation of intake measured in day 1 and subsequent days (r = 0.88, 0.81 and 0.79 for days 2-4, days 5-8 and days 9-12, respectively). A similar trend was observed on corresponding palatability indices. Individual animal preference and blocking did not affect intake and palatability indices significantly (P > 0.05), however significant (P < 0.0001) tree species differences were observed. Results on linear regression, correlation coefficients, palatability ranking and standard errors of means (adjusted palatability indices) indicate that, if palatability is done to predict long-term intake of MPTs, at least 5 days are appropriate in palatability assessment for sheep.Using mean palatability index (days 2-12), the MPTs were grouped into four clusters. The MPTs such as Leucaena leucocephala and Sesbania sesban which are known to have good nutritive value had high palatability. In the same classification group, there were less known species such as Acacia venosa, A. persiciflora, A. melanoxylon, A. hockii, A. polyacantha, Tamarindus indica, Chamaecytisus palmensis, Tipuana tipu, Indigofera arrecta and Atriplex nummularia. and Erythrina burana had poor palatability. These species seem to have little forage value for animals with short-term adaptation periods. Gliricida sepium and Calliandra calothyrsus although currently being used by farmers had a medium palatability ranking.

Effect of the tropical tannin-rich shrub legumes Calliandra calothyrsus and Flemingia macrophylla on methane emission and nitrogen and energy balance in growing lambs

“…soil fertility). For example, Kaitho et al (1996) stated that F. macrophylla has a low palatability and feeding value, as compared to Calliandra, which was found to have a medium palatability. In the present study, the intake of Flemingia was slightly higher than that of Calliandra.…”

“…It was shown for many parts of the tropics that shrub legumes, due to their deep root system and their ability to fix nitrogen, associated with a relatively high crude protein (CP) content, might present an alternative for smallholders to improve protein supply in forage-based diets for ruminants (e.g. Kaitho et al, 1996). At the same time, the high content of condensed tannins (CT) of many species adapted to acidic soils with low fertility is a major constraint for their use in ruminant diets.…”

Blood profiles of indigenous Pedi goats fed varying levels of <i>Vachellia karroo</i> leaf meal in <i>Setaria verticillata</i> hay-based diet

“…The grass and V. karroo leaves were chopped into smaller sizes of 13 mm and mixed according to the dietary treatments in Table 1, to avoid diet selection. The goats were fed ad libitum, allowing a 15 % refusal of each diet, as suggested by Kaitho et al (1996). Water was provided ad libitum.…”

Intake pattern and nutrient supply of lactating sheep selecting dried forage from woody plants and straw offered in binary or multiple choice

“…The 'binary choice' group was offered one of the test plants (in a randomised order between animals) and barley straw in separate troughs during the test period while the control group received only barley straw. The allocation of the feeds to the troughs was changed daily in both groups to prevent a 'habit reflex' (Kaitho et al, 1996). In order to minimise carry-over effects of the previous choice situation, 2 days followed between sub-periods where only barley straw but no test plant was offered.…”