Sesbania and lablab supplementation of oat hay basal diet fed to sheep with or without maize grain

This study investigated the effects of supplementing oat hay (OH; milk stage at harvest) with 250 g(as-fed) of either lablab (Dolichos lablab, 50 percent flowering at harvest) hay or sun dried leaves of sesbania (Sesbania sesban) with or without 91 g dry matter (DM) of crushed maize grain on rumen pH and ammonia concentration (RAC), intake, degradability, rumen particle passage rate (kl) (in Experiment 1), digestibility, microbial N synthesis and live weight gain (LWG) (in Experiment 2). A randomized complete block design with a 2 X 2 factorial structure was used in both experiments. In sacco DM and N degradabilities of the feeds were also determined in three sheeSesbania degraded faster and to a greater extent than lablab DM. Lablab N was more soluble than sesbania N. Maize-free diets of sesbania and lablab had similar k1 but k1 was lower (P0.05) affected the rate of OH degradation. Sesbania sustained higher (P<0.001) RAC, lower (P<0.05) potential degradability of OH and higher intakes (P<0.01; OH, DM and N), N digestibility (P<0.05), N retention (P<0.01) and microbial N synthesis (P<0.07) than lablab. Sesbania and lablab diets had similar rates of OH degradation, digestibility (DM, OM or NDF) and LWG. It was concluded that sesbania promoted higher OH intake and tended to increase (P<0.08) microbial N supply but had no effect on LWG. Maize grain tended to depress OH degradation rate but promoted faster LWG

Comparison between reconstituted sheep faeces and rumen fluid inocula and between in vitro and in sacco digestibility methods as predictors of intake and in vivo digestibility

This study (conducted in Debre Zeit, Ethiopia in 1993) examined (i) the effect of source of inoculum on in vitro dry matter (DM) digestibility (IVDMD) and gas production (GP) and (ii) the IVDMD, GP and in sacco degradability as predictors of in vivo DM digestibility (DMD( and intake. Six ruminally cannulated male sheep (used in the degradability studies and from which rumen fluid was harvested for the in vitro studies) and six intact sheep (from which faeces for reconstitution was obtained) were given teff straw ad libitum supplemented with 200 g/day of concentrate (1:1 mixture of noug (Guizotia abyssinica) cake and wheat middlings). In determining IVDMD on 26 feeds, pepsin HCl digestion was replaced with neutral detergent extraction. Microbial GP was measured on these feeds incubated with rumen fluid or reconstituted faeces inocula at various time periods. The degradability of each feed was determined by the nylon bag technique in three sheeEighty-eight intact male Ethiopian Menz type sheep (mean liveweight 25.6 (S.D. = 1.98) kg) were used in a randomized complete block experiment to determine intake and digestibility. Gas production using faeces inoculum (GP-F) was strongly related to GP using rumen fluid inoculum (GP-R) particularly at 48 h (R2 = 0.85; P<0.001) of incubation. The IVDMD obtained with reconstituted sheep faeces inoculum (IVDMD-F) had a strong positive relationship (R2=0.88; P<0.0001) with IVDM measured using rumen fluid (IVDMD-R). The IVDMD values obtained by centrifugation were positively related to those obtained by filtration for the rumen fluid (R2=0.61) and reconstituted faeces (R2=0.47) inocula. The relationship between degradability and in vivo DMD was generally poor for roughages but improved with the length of incubation for forage legumes, being strongest at 24 h (R2=0.54). The in vivo DMD had the strongest relationship with GP-R at 24 h of incubation for roughages (R2=0.64) and legumes (R2=0.84). Dry matter degradability was poorly related to DM intake for roughages (R<0.10), while these were closely related for legumes particularly at 6 h of incubation (R2=0.55). The relationship between GP-R and intake was strongest at 12 h of incubation for roughages (R2=0.41) but was generally weak for legumes. The IVDM accounted for a very low proportion of the variation in intake of roughages and legume forages. The gas production method was the best among the methods tested in predicting voluntary roughage intake, but not the intake of legumes. The nylon bag technique gave the best predictors (solubility, rate constant `c' and Lag phase) of legume intake (R2=0.98). The discussion suggests explanations for why the nylon bag technique predicted performance from forage legumes better than from roughages, why the technique was much better as a predictor of intake than of in vivo DMD, and why the gas production technique predicted in vivo DMD and not the intake of legumes. Reconstituted faeces inoculum may replace rumen fluid inoculum in in vitro procedures. The IVDM method is a less accurate predictor of in vivo DMD than GP and rumen degradability constants. Both feed factors and practices inherent in the methodologies may modify the predictiveness of indirect digestibility methods

The natural feed resources for ruminant animals in Nigeria

The paper assesses the feed resources available for ruminant production in Nigeria. The paper highlights ruminant animal contribution and feed situation and describes forage resoruces of the Savanna. Crop residue yield and utilization anare discussed and low and high cost input improvement scheme are summarised

Inter-relationships between chemical constituents, rumen dry matter and nitrogen degradability in fresh leaves of multipurpose trees

This work determined the inter-relationships between constituents, rumen dry matter (DM) and nitrogen (N) degradabilities of fresh leaves from 20 multipurpose tree (MPTs) accessions belonging to the following genera: Acacia(2), Cajanus (2), Chamaecytisus (2), Erythrina (2), Leucaena (8) and Sesbania (4). Significant differences were observed among genera in all assayed chemical attributes except hemicellulose. There was apparently no disappearance of N in A saligna after the initial solubility. All genera had similar DM and N solubility but varied in degradation rate of DM, effective degradability of DM and effective degradability of N. Except for A saligna, synchronization indices of the release of nutrients for each accession ranged from perfect (0.93) to poor (-0.31) for soluble nutrients and from moderate (0.75) to very poor (-0.81) for insoluble slowly degradable nutrients because N was in excess. Inter-relationships among chemical constituents, DM and N degradation constants were established using correlation and regression analyses. Negative correlation occured between N solubility and proanthocyanidins, N degradation rate and hemicellulose and either NDF or hemicellulose or PAs, while N degradation rate was positively correlated with N content. Equations for predicting N degradability characteristics were set. Practical implications of DM degradability and nutrient release synchrony indices in relation to basal roughage intake and microbial protein synthesis were discussed. It was concluded that a mixed model could adequately predict N degradability of fresh forages and alleviate analytical cost. A functional approach of classifying browses is outlined

Degradability of forage protein supplements and their effects on the kinetics of digestion and passage

Degradability characteristics of oats hay (harvested at milk stage), oats straw, wheat middlings and forage legumes (lablab (Lablab purpureus)) hay, leaves of sesbania (Sesbania sesban) and tagasaste (Chamaecytisus palmensis)) were evaluated in three sheep given native hay supplemented with cottonseed cake. In Trial 2, 18 fistulated male sheep were given six dietary treatments: ad libitum oats straw with 250 g (as fed) of lablab hay, wheat middlings (WM), sesbania or tagasaste. The effect of these diets on degradabilities of oats hay and oats straw and rumen particulate passage rate (k1) were determined. Oats hay had higher (P0.05) on the intake of oats hay, total DM or NDF. It was concluded that supplementation with forage legumes had no effect on oats hay DM degradation rate but tended to enhance k1. Forage legumes that disappear fast from the rumen may induce lower substitution rates

The effects of cottonseed cake with or without molasses on feed utilization, purine excretion, and milk production of Boran (Bos indicus) cows fed a mixture of wheat and oat straw

The effects of 1.35, 1.8, or 2.25 kg dry matter (DM) of cottonseed cake, with (1.85 kg DM) or without molasses, on straw intake, diet digestibility, live-weight change, excretion of purine derivative (PD), and milk production of Boran (Bos indicus) cows were studied. There were no significant (P > 0.05) interactions. Straw intake tended also to decrease from 5.18 to 4.94 kg DM (P 0.05)

The utilization of teff (Eragrostis tef) straw by sheep fed supplementary forage legumes with or without either crushed maize grain or wheat bran

This study examined the interaction of high energy substrates (ES: crushed maize grain (MG) and wheat bran (WB) with forage legumes (FLs), such as Lablab purpureus hay, sun dried leaves of Sesbania sesban and tagasaste (Chamaecytisus palmensis), on ruminal microbial activity (indexed by the degradability and digestibility of teff (Eragrotis tef) straw (TS), urinary excretion of purine derivatives (PD)) and on nitrogen retention. The diets comprised TS fed alone ad libitum (TSA) or TSA supplemented with either of the above FLs (175 g/day) with or without 47 g/day of either MG or WB. The 10 diets were fed to 20 ruminally cannulated sheep in two periods during which each of the degradabilities of TS and of the FL corresponding to that which the sheep were consuming were determined in sacco. The particulate rate of passage was also determined using chromium mordanted TS. Forty castrated male Ethiopian Menz sheep were used in a randomised complete block design to determine the effects of the above diets on intake, digestibility, urinary PD, microbial N synthesis and N retention. Both the potential and the effective degradabilities indicated that sesbania was the most degradable, and lablab the least. Supplementation with Fs alone increased the rate of degradation of TS by 50 to 142 percent, the rate of passage of particles (kp), the intake of TS, dry matter (DM), organic matter (OM), nitrogen (N) and neutral detergent fibre (NDF); had no effect on the digestibility of DM, OM, teff and NDF; increased faecal N. urinary N, N retention, urinary allantoin, total and microbial PD, microbial N and the efficiency of microbial N synthesis. Forages were similar in the degradation rate of TS but differed in the intake of TS, DM and OM in the order: sesbania > tagasaste > lablab. Lablab diets sustained higher kp than either the sesbania or tagasaste diets. Sesbania diets, compared to lablab or tagasaste diets, depressed the digestibilities of DM, OM, NDF, ADV and TS; increased faecal, urinary and retained N, urinary allantoin, total and microbial PD, microbial N and efficiency of microbial N synthesis. Further supplementation with high ES depressed kp, tended to depress (P>0.05) the degradation rate of TS by 14-45 percent, and that of FLs by 21-47 percent; increased faecal N, retained N, urinary allantoin, total and microbial PD, microbial N and the efficiency of microbial N synthesis; had no effect of digestibility and urinary N. Maize depressed the digestibility of ADF and urinary N. but increased urine allantoin relative to wheat bran while both energy substrates elicited similar N retention and microbial N synthesis. Supplementing straw diets with FLs is beneficial in terms of intake, microbial N synthesis and yield. These benefits correlate positively with the degradability of FLs and are further improved by a complementary high energy substrate

Digestible organic matter requirements of Ethiopian Menz sheep: Model and application

A static model for predicting either the growth rates or digestible organic matter (DOMI) required to meet predetermined levels of growth is developed. Parameters in the model were derived using data collected in ILRI-DZ laboratory from 6 growth studies (involving a total of 242 Ethiopian Menz sheep) supported by metabolism studies. DOMI = alpha W0.75 + WG/(Emax e-k1W.f(WG); f(WG)=e K2.WG where a = 28.20 = Maintenance DOMI/kg W0.75, Emax = 0.949 = is the maximum WG that can be achieved per unit DOMI, k1 = 0.0241 = fractional decline rates of the efficiency with increasing W, k2 = 0.0070 = fractional decline rates of the efficiency with increasing WG, W and WG = live weight and live weight gain, respectively. The performance of the model was tested using published data. There was a good agreement between the observed and predicted requirements of tropical highland sheep, but not for sheep inhabiting the hot humid tropical habitat. The discussion suggested why some proportion of the variation in DOMI was unexplained by the model. Since the model could not account for 0.37 of the variation, it was concluded that there is scope for improvement of the model with the advent of new evidence on the subject