R.J. Kaitho

Palatability of wilted and dried multipurpose tree species fed to sheep and goats

Palatability indices of dry and wilted 18 multipurpose tree species (MPTs) were determined using 12 wethers and 12 bucks (mean ± SD liveweight 17.5 ± 1.24 kg and 20.5 ± 1.46 kg, respectively), blocked into two groups on liveweight and age, housed in a roofed and half-walled shed with individual feeding pens. The 18 MPTs were randomly grouped into sets of six by form (dried and wilted), such that each animal received three samples of each form. Each animal received 0.5 kg teff straw (Eragrostis tef) in addition to 0.4 kg and 0.2 kg of the wilted and dry forms of the appropriate MPTs, respectively, daily at 08,00 h over a 12-day experimental period. Dry matter intake of MPTs on day 1 (A1), average intakes on days 2–4 (A2), days 5–8 (A3), days 9–12 (A4) and days 2–12 (A5) were compared. A significant (P < 0.0001) decrease in intake, with correlation coefficients of r = 0.92 (A1 and A2), r = 0.88 (A1 and A5) and r = 0.85 (A1 and A3) in sheep, was observed. A similar trend was observed for palatability indices R1, R2, R3 and R4. A close relationship was observed between R2 and R5 (r = 0.91), R3 and R5 (r = 0.97), and R4 and R5 (r = 0.94). R1 was poorly correlated with R5 (r = 0.61). The same trend was found in goats. Linear regressions of A5 on A1 A5 on A2, A5 on A3 and A5 on A4 (adj. r2 = 0.81, 0.95, 0.97, 0.94 and r2 = 0.64, 0.90, 0.97, 0.94 in sheep and goats, respectively) showed that the best relationship existed between A5 and A3. The results of analysis of variance for palatability index R5 showed that the palatability index significantly (P < 0.001) depended on previous clustering and animal species. The cluster means for R5 were 1.34, 1.02, 0.68 and 0.54 for clusters 1, 2, 3 and 4, respectively. However, the palatability indices for goats were more than double those for sheep (1.33 vs. 0.48). There were no significant interaction effects for cluster, form and animal species. In this study the form of feed (wilted or dry) did not affect the palatability index. Acacia persiciflora, Leucaena leucocephala and Chamaecytisus palmensis were ranked high by both sheep and goats.

Relationships between preference, rumen degradability, gas production and chemical composition of browses

The aim of this work was to assess whether degradability, gas production or chemical constituents could predict the preference of browses. Forty tropical browse species leaves with a crude protein (CP) content ranging from 79 to 307 g kg-1 DM were used for this study. The neutral detergent fibre (NDF) ranged from 220 to 694 g kg-1 DM, while acid detergent fibre (ADF) ranged from 146 to 523 g kg-1 DM. The NDF-bound nitrogen (NDFN) and ADF-bound nitrogen were particularly high in Calliandra calothyrsus, Acacia polyacantha, Sesbania sesban, Acacia venosa and Acacia hockii. High levels of tannins were observed in Acacia species especially A. dolichocephala, A. hockii, A. microbotrya and A. salicina. High levels were also observed in Flemingia macrophyla and Leucaena pallida. The browse species differed (P < 0.05) in DM in sacco degradability coefficients. High potential degradability (PD) and effective degradability (ED) were observed in Sesbania spp, Moringa stenopetala, Indigofera arrecta, Chamaecytisus palmensis and Atriplex spp. The browses differed (P < 0.05) in asymptotic gas (Ag) production (ml g-1 OM), but had similar (P > 0.05) times of incubation at which half of the asymptotic gas had been formed. Preference and DM intake were positively correlated (P < 0.01) to NDFN, but negatively correlated (P < 0.05) to NDF and ADF. The PD and Ag were negatively (P < 0.001) related to NDF, ADF and lignin. Total phenols (TP) and condensed tannins (CT) were negatively (P < 0.05) related to PD, ED and Ag. A positive correlation was observed between CT and NDF-bound condensed tannins (r = 0.55, P < 0.001) and, CT and TP (r = 0.40, P < 0.01). Prediction equations were poor for DM intake and preference, moderate for gas production and good for potential and effective degradabilities. The phenolic components were more related to dry matter degradation and gas production than to preference and dry matter intake. NDFN and Ag made a positive contribution to both preference and DM intake. It was concluded that chemical constitutes such as N, NDF, NDFN, ADF and lignin are essential to predict the nutritive value of browses.

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

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 (Ai/Di). Using daily Eragrostis tef straw offer (TD) and intake (T), relative palatability indices were calculated as Ri = (Ai/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. polycantha, Tamarindus indica, Chamaecytisus palmensis, Tipuana tipu, Indigofera arrecta and Atriplex nummularia. Flemingia macrophylla, Erythrina abyssinica, Acacia salicina, Acacia coriacea, Albizia schimperiana, Ceratonia siliqua, Casuarina glauca 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 feeding graded levels of Leucaena leucocephala, Leucaena pallida, Sesbania sesban and Chamaecytisus palmensis supplements to teff straw given to Ethiopian highland sheep

Abstract The effect of feeding graded levels of Leucaena leucocephala , Leucaena pallida , Sesbania sesban and Chamaecytisus palmensis supplements on intake, digestibility and live weight changes was evaluated using 102 male Ethiopian highland sheep in a 90-day trial. Teff straw ( Eragrostis tef ) was fed ad libitum (control diet), or supplemented with graded levels (15, 30, 45, 60% of ration dry matter intake) of L. leucocephala, L. pallida, C. palmensis or S. sesban in a randomized complete block design. Significant ( P −1 supplement) increased with increasing levels of supplementation. Substitution rate varied from 162 to 528 in L. pallida , −89 to 312 in L. leucocephala, −566 to 231 in S. sesban and −10 to 134 in C. palmensis supplemented diets. Dry matter and digestible organic matter intake increased significantly ( P L. leucocephala , C. palmensis and S. sesban , but not in L. pallida . Live weight gain increased significantly ( P −1 ) while the supplemented ones gained weight in the range of 6.5–65.2 g d −1 . The maximum live weight gain (65.2 g d −1 ) was observed in sheep fed a diet with 60% L. pallida . The optimum levels of browse supplementation in terms of live weight gain per g supplement were 45, 45, 30, 30% DM of total ration for L. leucocephala , L. pallida , C. palmensis and S. sesban , respectively. A close relationship between live weight gain and amount of supplement was observed. The digestibilities of DM, OM, N and supplement DM increased significantly ( P P >0.05) differences were observed in NDF digestibility. Faecal nitrogen, urinary nitrogen output and nitrogen retention increased significantly ( P

Utilization of browse supplements with varying tannin levels by Ethiopian Menz sheep. 1. Intake, digestibility and live weight changes

The effect of tannins in browse supplements on intake, digestibility and live weight changes was evaluated using sixty-six male Ethiopian Menz sheep in a 90-day trial. Teff straw (Eragrostis tef) was fed ad libitum (control diet), or supplemented with 190 g dried leaves of six Sesbania sesban accessions with increasing levels of condensed tannin (S1, S2, S3, S4, S5 and S6), lablab (Dolichos lablab), tagasaste (Chamaecytisus palmensis), leucaena (Leucaena leucocephala) and goetzei (Sesbania goetzei), in a completely randomized block design. The condensed tannins were highest in goetzei, S6, S5 and leucaena, intermediate in S4, S3, S2 and S1, and lowest in tagasaste and lablab. The forages differed significantly (P < 0.05) in their rates of degradation and truly undegradable dry matter. Lablab had lower water solubility and higher (P < 0.05) truly undegradable dry matter than the other browse supplements. With increasing tannin levels among Sesbania accessions, there was a significant decrease (P < 0.05) in the rate of degradation. Animals supplemented with forage legumes with low condensed tannin levels such as lablab, S1, S2, and S3 had a lower teff straw intake than those on the control diet. The converse was true for those fed with the high tannin supplements such as S4, S5, S6 and goetzei. Supplementation significantly (P < 0.05) increased total dry matter intake and live weight gains (LWG). The animals on the control diet lost weight (–1.9 g/kgW0.75, while the supplemented animals gained between 2.9 and 4.4 g/kgW0.75 daily. Leucaena supplementation promoted higher (P < 0.05) LWG than lablab, S1 and goetzei. With increasing tannin levels among Sesbania accessions, there was an increase (S1 < S2 < S3 < S4) followed by a decrease (S6 > S5 > goetzei) in LWG. The digestibilities of total DM and the supplements did not differ significantly (P < 0.05) between the diets, although the neutral detergent fibre (NDF) digestibility decreased significantly (P < 0.05) with supplementation. The control diet had significantly higher NDF digestibility than the leucaena, S3, S4, S5 and S6 supplemented diets. Results have beneficial attributes at low levels in ruminants. Condensed tannins confer important advantages in ruminant nutrition with respect to the prevention of excessive degradation of protein in the rumen.

Effect of leucaena and sesbania supplementation on body growth and scrotal circumference of Ethiopian highland sheep and goats fed teff straw basal diet

The long term effect of supplementation of Leucaena pallida and Sesbania sesban on growth and reproduction performance was determined on 30 male Ethiopian highland sheep and 25 East African goats. Unchopped teff straw (Eragrostis tef) was given ad libitum and supplemented with either wheat bran (150 g), Leucaena (200 or 400 g) or Sesbania (200 or 400 g). The animals were blocked (by species) on live weight and scrotal circumference (SC), and randomly assigned within blocks to the five dietary treatments in a randomized complete block design. Animals supplemented with 400 g of the browses had significantly higher (P < 0.05) intake of DM and live weight gain than the other treatments. Sheep had significantly higher (P < 0.05) teff straw intake than goats (47.3 and 38.7 g kg W-0.75, respectively). The correlation between SC and body weight was high and significant in goats (r2 = 0.70, P < 0.001) and lower in sheep (r2 = 0.43, P < 0.01). Live weight gain and scrotal circumference changes were significantly (P < 0.01) different between treatments in both animal species. Supplementation with browses increased faecal nitrogen output and nitrogen retention. The results from this study indicated type and level of supplement variations on the growth and reproductive performance of sheep and goats.

Nitrogen in browse species: ruminal degradability and post-ruminal digestibility measured by mobile nylon bag and in vitro techniques.

This study determined nitrogen degradability and digestibility of rumen undegradable nitrogen using mobile nylon bag (MNB) and pepsin/ pancreatin in vitro technique (IV) of 40 browse species. Thirty Ethiopian highland sheep fitted with rumen cannulae were used in nitrogen (N) degradability studies. Six steers fitted with rumen cannulae were used in preparation of 16-h and 24-h ruminal undegraded residues and four steers fitted with distal abomasal cannulae were used in MNB technique. The browses varied widely in nitrogen solubility (15-468 g kg -1 ), potential degradability (223-976 g kg -1 ), rate of degradation (0.13-24% h -1 ) and effective degradability (135-821 g kg -1 ). The apparent N digestibility (ND) of the rumen undegraded residues differed significantly (P 0.05) was observed in ND of 16-h and 24-h residues. The ND of the 16-h residue varied from -218 to 759 g kg -1 and 169 to 851 g kg -1 for MNB and IV methods, respectively. Browse species with high tannin contents such as Acacia hockii, A horrida, A melanoxylon, A persiciflora, A salicina, A saligna and Flemingia macrophylla had high rumen by-pass and a low ND, while Sesbania spp and A nilotica with low tannin contents underwent rapid and extensive dry matter and nitrogen degradation in the rumen. Acacia sieberiana, Chamaecytisus palmensis, Erythrina spp, Gliricidia sepium, Samanea saman and Enterolobium cyclocarpum had high proportions of protein escaping rumen degradation (BP) and with a high proportion of the by-pass protein digested in the intestine, therefore these browses had a high potential as protein supplements. The ND measured with the MNB were significantly lower (P < 0.001) than by the IV method. The correlation between MNB and IV was high and significant (R 2 = 0.89, P < 0.0001) as also indicated by the regression equation (SE in parentheses): MNB = -22.8 (4.55) +1.0 (0.08)IV (RSD = 10.56, R 2 = 0.79, n = 40, P < 0.001). The intercept of the linear relationship obtained was different from zero while the slope was not different from unity. Multiple regression analysis suggested that some of the unexplained variation could be accounted for by either nitrogen, acid detergent fibre, total phenolics or neutral detergent fibre bound tannin levels in browses. The IV method is accurate for estimating digestibility of ruminally undegradable N, and hence its use would considerably reduce the need for delicate surgery and the elaborate procedures involving the MNB technique.

Utilization of browse supplements with varying tannin levels by Ethiopian Menz sheep 2. Nitrogen metabolism.

The effect of different condensed tannins concentrations on protein metabolism from browse supplements was investigated in a 90-day trial using sixty-six male Ethiopian Menz sheep. Teff straw (Eragrostis tef) was fed ad libitum (control diet), or supplemented with 190 g dried leaves of six Sesbania sesban accessions with increasing levels of condensed tannin (S1, S2, S3, S4, S5 and S6), lablab (Dolichos lablab), tagasaste (Chamaecytisus palmensis), leucaena (Leucaena leucocephala) and goetzei (Sesbania goetzei) in a completely randomized block design. The condensed tannins were highest in goetzei; S6, S5 and leucaena, intermediate in S4, S3, S2 and S1, and lowest in tagasaste and lablab. The supplemented animals had significantly (P < 0.05) higher total dry matter and nitrogen (N) intake than the ones fed teff straw alone. The digestibility of N was lower for the control diet than for any other treatment (P < 0.05). S1 and S2 supplemented diets had significantly higher (P < 0.05) N digestibilities than all other diets. Faecal N, urinary N and urinary N per kg N excreted were significantly different (P < 0.0001) between diets. With increasing tannin levels (among Sesbania accessions) there was a significant decrease (P < 0.05) in urinary N (S1 > S2 > S3 > S4 > S5), and an increase (P < 0.05) in faecal N (S1 < S2 < S3 < S4 < S5). Supplementation increased faecal N output significantly (P < 0.0001) as well as the N retention. Among the forage supplements, N retention was significantly (P < 0.0001) lower in lablab-, tagasaste-, leucaena-, S4- and goetzei-supplemented diets, than for S1, S2, S5 and S6. Apparent nitrogen digestibility was positively correlated (P < 0.001) with the supplement dry matter and crude protein (CP) degradation after 24 h (r = 0.93 and r = 0.85, respectively), the CP content (r = 0.87), and was negatively correlated with acid detergent fibre and neutral detergent fibre (r = –0.87 and –0.87, respectively). The CP degradability characteristics of the forages differed (P < 0.001) in water solubility (93–470 g kg-1 CP), rate of degradation (2.58–9.73 %/h), lag phase (–1.36–13.37 h), and estimated escape protein (262–619 g kg-1 CP). With increasing tannin levels (among Sesbania accessions), there was a significant decrease (P < 0.0001) in the rate of degradation (S1 > S2 > S3 > S4 > S5), and an increase in the estimated escape protein. The estimated rumen degradable protein (supplements) varied from 482 to 744 g kg-1 CP, while intestine digestible protein and the undegradable protein varied from 140 to 314 g kg-1 CP, hence the browses can supply adequate levels of rumen degradable and bypass protein.