No abstract

A study to compare the effects of supplementing Delonix elata, Grewia similis, Tamarindus indica and sunflower seed cake on intake and growth rate of dual-purpose goats fed low quality Buffel grass (Cenchrus ciliaris) hay was carried out. Twenty-eight male goats aged five to seven months (mean weight 12.93±3.94 kg) were randomly allocated to four dietary groups in a completely randomised design. The diets were hay plus Grewia similis, hay plus Delonix elata, hay plus Tamarindus indica and hay plus sunflower seed cake. All diets were supplemented with maize bran. The experimental period was 90 days. Voluntary dry matter intake of the supplements was higher for Tamarindus indica (275.5 g/day) and Grewia similis (201.8 g/day) and lowest for sunflower seed cake (81 g/day). Goats supplemented with Grewia similis had the highest hay intake (183.8 g/day) while those supplemented with sunflower seed cake had the lowest hay intake (98.9 g/day). Animals fed browse supplements gained significantly more weight (p<0.001) than those with sunflower seed cake. There were no significant differences in live weight change between goats fed the different browses. However, those fed Tamarindus indica gained an average of 20.79 g/d which was slightly higher than the gains for those on Grewia similis and Delonix elata while those fed sunflower seed cake lost weight. Correspondingly, goats supplemented with browse leaf meals had higher feed conversion ratios than those supplemented with sunflower seed cake and required 23.91 to 35.06 g DM of feed to produce one g of weight gain per day. In a separate study, the DM disappearance pattern indicated that Grewia similis and Delonix elata were highly degradable compared to Tamarindus indica. At 24 h of incubation, DM degradability was 627, 588 and 345 g/kg DM for Grewia similis, Delonix elata and Tamarindus indica, respectively. In another study in vivo DM digestibility ranged from 46.1% (for hay alone) to 56.2% (for hay plus Grewia similis). It was concluded that the addition of Tamarindus indica, Grewia similis and Delonix elata leaf meals to Cenchrus ciliaris hay resulted in increased total DM intake, in vivo digestibility and growth rate. Therefore, leaf meals of indigenous browses particularly Tamarindus indica and Grewia similis could be used as supplementary feeds for small ruminants grazing on poor quality roughages during the dry season rather than use of expensive, less effective and intermittently available sunflower seed cake.

Goat production systems increasingly involve indoor feeding. To facilitate manger design, there is need for information on the ability to reach for food, such as that for cattle given food through tombstone barriers. In the first study, 20 castrated and 20 non-pregnant female Saanens of mean live weight (M) 39-3 (s.d. 14-42) kg were trained to reach, through a vertical tombstone barrier, for concentrate meal placed on a horizontal platform attached to the barrier. The barrier allowed the neck but not the shoulders to pass through. It was hypothesized that horizontal reach forwards (F, distance from mid point of barrier to uneaten meal) and sideways (S, distances sideways from mid point of barrier to uneaten meal adjacent to barrier) would be a function of height of platform above the floor and size of goat. Because of size, eight goats (mean M, 16-4 kg) were unable to reach meal when the platform height was 75 cm. Mean (s.e.) values for F at platform heights 0, 25, 50 and 75 cm were 55-9 (0-68), 58-8 (0-64), 57-8 (0-69) and 41-1 (1-23) cm respectively. Values for S were smaller, but followed a similar pattern (49-4 (0-64), 52-4 (0-56), 53-2 (0-53), 36-6 (1-17) cm). Linear regression of either F or S on M and linear body dimensions (e.g. body length, neck and head length, neck-joint height, withers height) showed high correlations with R 2 values being 0-8 or more. In the second study, 10 castrated and 10 non-pregnant females (M, 48-7 (s.d. 14-56) kg) were trained to reach through the tombstone barrier for concentrate pellets 'glued', using molasses, on to a vertical plate. It was hypothesized that vertical reach (V, distance from floor to uneaten pellets) would be a function of distance between barrier and plate (20, 30, 40, 45, 50 cm), height of step (0,14-2, 28-4, 42-6 cm) on which goats placed their forelegs and size of goat. Four goats (mean M, 29-9 kg) were unable to reach pellets when the plate was at 45 and 50 cm. Mean (s.e.) V values decreased with increasing plate distance and increased with step height (e.g. at 0 cm step heights respectively). Linear regression of V on body weight and body dimensions (e.g. body length, heart girth, withers height) showed high correlations (R 2 > 0-8). It is concluded that for practical purposes, body weight is a satisfactory predictor of reach. The results support the hypotheses. The data will facilitate the design of mangers for goats with body weights and dimensions in the range of those used in the present study.

Forty growing goats (20 males and 20 females) were used in a 90-day growth and intake study to evaluate the potential of Albizia lebbeck (ABC) based concentrate as compared with Gliricidia sepium (GBC), Leucaena leucocephala (LBC), and Moringa oleifera (MBC) based concentrates with cotton seed cake (CSC) as a control. The animals were fed a basal diet of maize stover and supplemented daily with 30 g/kg W 0.75 of ABC, GBC, LBC, MBC, and CSC. They were compounded so as to formulate iso-protein diets. Treatment effects were significant (p < 0.05) for growth rates in that with the exception of GBC, goats on CSC exhibited significantly higher gains compared to counterparts in other treatments. The total DM intake was between 50.6 and 52.6 g/kg W 0.75 /day and there were no significant (p > 0.05) differences among treatments. There were significant differences (p < 0.05) among treatments for maize stover intake. CSC based treatment showed the highest intake with insignificant (p > 0.05) differences amongst the leaf meal based concentrates. It can be concluded that Albizia lebbeck had similar potential to the other leaf meal based supplements studied but had lower potential compared to a cotton seed cake based supplement, as protein sources for growing goats fed a poor quality basal diet.

Two experiments were conducted in the Makambako division of the southern highlands of Tanzania to investigate the effects of regrowth period, season and harvesting frequency on the yield and nutritive value of Chloris gayana. The first experiment was conducted in 2002 in a 4X2 factorial arrangement in a complete randomised block design with six replications. The treatments were period of regrowth (three, six, nine and 12 weeks) and season (early wet season January-March and late wet season April-June). The second experiment was conducted in 2003 in a complete randomised design with six replications. The treatments were four cutting frequencies (three, six, nine and 12 weeks). In Experiment 1, the dry matter yield (DMY) ranged from 1.09-7.99t ha -1 and from 0.97-3.53t ha -1 (P < 0.05), while the crude protein (CP) content ranged from 13.9-8.25% and 16.09-9.85% (P < 0.05) in the early and late wet seasons, respectively. In vitro dry matter digestibility (IVDMD) and metabolisable energy (ME) declined faster with increasing periods of growth in the early than in the late wet season. ME ranged from 9.21-7.29MJ kg -1 DM (P < 0.05) and 8.02-7.87MJ kg -1 DM (P > 0.05) in the early and late wet seasons, respectively. For Experiment 2, the nine-and 12-week cutting frequencies did not differ (P > 0.05) in terms of cumulative DMY (19.07 versus 18.93t ha -1 ) but produced nearly twice as much as the three-and six-week cutting frequencies (10.18 and 8.32t ha -1 ). CP, IVDMD and ME decreased while neutral detergent fibre (NDF) increased with decreased cutting frequency. The results of the present study suggest that the optimal balance of dry matter yield and nutritive value of C. gayana at Makambako is reached at the ninth week of regrowth. Regardless of season, dairy farmers in this area who are feeding pure C. gayana must provide energy supplement to their dairy cows.