| dc.description.abstract | protejn_rich forages (PRFs) could be cheaper alternative crude protein supplements for ruminants compared to commercial concentrates which are unaffordable to many smallholder farmers. However, effect of supplementation with PRFs on performance of the Kenya dual-purpose goats (KDPGs) in the country has not been well evaluated. Therefore, the objective of this study was to I investigate the effects of supplementing KDPGs on a basal diet of Rhodes grass {Chloris gayana) hay (confined feeding) (CF) or on natural pastures (free-range) (FR) with different levels of two (2) PRFs, Calliandra calothyrsus and Lucerne {Medicago sativci) on nutrients intake, lactation performance, pre-weaning kid performance and post-weaning weight gain. To achieve this, four (4) I experiments were conducted.
In experiment 1, to investigate the effects of supplementation on milk yield (MY), birth weight (BWT), pre-weaning average daily gain (pre-ADG) and weaning weight (WWT), 55 pregnant DPGs 1(25 for FR and 30 for CF) were selected at random from a flock of 200 does. They were randomly allocated to five (5) treatment diets four (4) weeks prior to kidding. Composition of the diets was:- |Tl, (control) - Rhodes grass hay or grazing only for CF or FR respectively; T2 and T3, 250 and 500 jgd'1 of C. calothyrsus respectively; T4 and T5, 250 and 500 gd'1 of Lucerne respectively. For CF,
daily milk yields were significantly lower at 260, 414, 640, 370 and 521 gd'1 for T1 to T5
respectively than FR. The respective values for FR were 355, 568, 813, 508 and 693 gd . Kids born to supplemented does had a significantly higher BWT than the control, 1.9, 2.5, 3.3, 2.2 and 2.9 kg jfor T1 to T5 respectively, for CF, and 2.1, 3.0, 3.8, 2.7 and 3.3 kg for FR. The kids pre-ADG reflected the trend in MY and BWT at 47.8, 64.3, 91.5, 53.8 and 72.9 gd'1 for Tl to T5 respectively, for CF, and 57.4, 78.3, I 12.4, 66.3 and 90.7 gd'1 for FR. Kids bom to the supplemented does also had higher (P<0.05) WWT than the control. The respective WWT (kg) for Tl to T5 were 7.8, 9.5, 13.3, 8.4 and 10.7 for CF; and 9.0, 11.7, 14.7, 10.1 and 13.5 for FR. Under both management systems, at both levels of supplementation, animals on Calliandra performed significantly (P<0.05) better than those on Lucerne based diets in MY, BWT, pre-ADG and WWT. These results indicated that supplementation with PRFs improved MY, BWT, Pre-ADG and WWT and that animals on FR performed significantly (P<0.05) better compared to those on CF, while those on Calliandra had significantly (P<0 05) better performance than those on Lucerne based diets
In experiment 2, to investigate the effects of supplementation with PRFs on post-weaning Performance, 60 weaner DPGs (30 for each management system) were randomly allocated to 5
treatment diets for 8 months as follows:- Tl (control) - Rhodes grass hay or grazing only for CF or PR respectively. T2 and T3, 100 and 200 gd ' of C. calothyrsus respectively; T4 and T5, 100 and ^00 ud'1 of Lucerne respectively. For CF, the respective values for post-ADG (gd ') for Tl to T5 were, 17.4, 30.8, 56 8. 26 1 and 40.1 The respective values for FR were, 32.2, 46.1, 61.3, 41.1 and 50 0 The values for YVVT (kg) for CF were 12.0, 14.6, 20.0, 12.8 and 16.3 for Tl to T5 respectively. p0r FR the respective values were 15.6, 19.6, 23.0, 17.3 and 21.4. Supplementation significantly /p<0.05) increased post-weaning growth. At both levels of supplementation, under both management systems weaners on ('alhandra performed significantly (P<0.05) better than those on Lucerne based diets in post-ADG and YWT, while those under FR performed significantly (P<0.05) better than those under CF.
In experiment 3, to investigate the effects of supplementation with PRFs on in-vivo digestibility, N balance and rumen fermentation parameters, Rhodes grass hay was supplemented with graded levels of C. calothyrsus and Lucerne. Five (5) mature dual-purpose castrates surgically fitted with rumen cannulae were fed on a basal diet of Rhodes grass hay in a 5 x 5 Latin square design. The 5 treatment diets were Tl, control (Rhodes grass hay only); T2 and T3, 250 and 500 gd'1 of C. calothyrsus respectively; T4 and T5, 250 and 500 gd'1 of Lucerne respectively. Supplementation increased (P<0.05) OM in-vivo digestibility 60.3, 70.1, 72.3, 68.5 and 71.2% for Tl to T5 respectively; and N retention, the respective values of N retained were 4.1, 34.8, 52.3, 29.5 and 43.5% of N intake for Tl to T5. At similar levels of supplementation, N retention was higher (P<0.05) in animals on Calliandra than those on Lucerne based diets and increased (P<0.05) with level of supplementation. Supplementation increased concentration of rumen NH3-N 12.4, 13.2, 17.9, 12.6 and 16.4 mg 100ml' and VFA 10.6, 11.4, 14.9, 10.9 and 13.7 mmol 100ml'1 forTl to T5 respectively and lowered rumen pH 6.8, 6.5, 6.4. 6.5 and 6.5 for Tl to T5 respectively. These results indicated that supplementation with PRFs increased in-vivo digestibility, N balance and rumen fermentation. At both levels of supplementation these values were higher for Calliandra than Lucerne based diets and increased with level of supplementation
In experiment 4, to investigate the effects of supplementation with PRFs on rumen degradation characteristics five (5) mature dual-purpose castrates surgically fitted with rumen cannulae were fed on a basal diet of Rhodes grass hay in a 5 x 5 Latin square design The 5 treatment diets were similar to experiment 3. Supplementation increased (P<0.05) OM disappearance and potential degradability (PD) and effective degradability (ED) of OM and CP in the rumen, with level of supplementation.
The available organic matter fermented in the rumen (DOMR) increased (P<0.01) from 193.5 for the control to 372.0, 570.4, 332.0 and 494.6 gd'1 for T2 to T5 respectively. By-pass protein (BP) increased (P<0.01) from 494.5 for the control to 524.4, 540.3, 523.7 and 535.5 g kg'CP for T2 to T5 the respective values of intestine degradable protein (IDP) were 188.7, 256.6, 286.3, 241.0 and
262.2 g kg'CP for TI to T5 respectively. For each of the parameters the values were higher for (\illiandra than Lucerne based diets at both levels of supplementation and increased with level of supplementation for both legumes.
It was concluded that supplementation improved (P<0.05) animal performance in terms of milk yield and growth rate through improved nutrients intake, in-vivo digestibility, N retention, rumen fermentation and rumen degradability and that Calliandra was a better supplement for goats than Lucerne. | |
