الفهرس 
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Abstract
Experiment 1 was carried out at the By-Products Utilization
Department, Animal Production Research Institute, Agricultural Research
Center, Ministry of Agriculture, at Dokki. Egypt, during January, 1997 to
determine the in vitro DM and OM disappearance values of four plant
protein sources (undecorticated cotton seed cake, UDSCS; linseed meal,
LSM; soybean meal, SBM and sunflower meal, SFM) each without or
with urea (U) or meat and bone meal (MBM) or U+MBM. The diets used
in this experiment contained nearly similar CP and TDN values.
Results obtained were as follows:
1- Soybean meal diets (regardless of protein supplement effect) recorded
the highest (best) IVDMD and IVOMD values (76.99 and 77.84%,
respectively), followed by those ofSFM ones (74.81 and 75.51 %),
while, UDCSC and LSM diets had nearly the same IVDMD (72.83
and 72.02%) and IVOMD (72.12 and 72.86%) values, respectively.
The differences in IVDMD and IVOMD values due to plant protein
source effect were significant (P < 0.05), except for those between
LSM and UDCSC values.
2- Regardless of plant protein source effect, diets supplemented with U
showed the highest (P< 0.05) IVDMD value (77.72%) compared with
that of the unsupp1emented diets (74.51 %). Whereas, diets
supplemented with either MBM or MBM + U recorded the lowest
(P< 0.05) IVDMD values being 72.18 and 72.25%, respectively,
without significant differences between these two values. Also, diets
supplemented with U achieved the highest IVOMD value (76.64%),
whereas, those supplemented with neither MBM nor MBM+U
showed the lowest ones (P < 0.05), being 73.10 and 73.11 %,
respectively. The differences in IVOMD due to protein supplement
effect between unsupplemented and U supplemented diets or between
MBM and MBM+U supplemented ones, were not significant.
Experiment 2 was conducted at El-Nobarya Experimental
Station, Animal Production Research Institute, Agricultural Research
Center, Ministry of Agricultural at summer season of 1997. Thirty six
Barki lambs of about 18 weeks old and an average initial live body
weight of 17.38 Kg were used in this experiment. Three sources of plant
proteins, being UDCSC, LSM and SFM were used to formulate three
rations, each was either unsupplemented or supplemented with 1% U. All
rations were isonitrogenous and isoenergetic. Rice straw was offered ad
lib., while the experimental rations were allowed according to the NRC
(1975) recommendations based on animal body weight. The effect of the
tested rations on nutrients digestibilities feeding values, nitrogen balance,
microbial protein synthesis as well as growth performance of fattening
lambs were studied. Rumen liquor parameters and some blood
constituents were also studied. The duration of the feeding trial was 126
days (18 weeks).
Results of this study could be summarized as follows:
1- Values recorded for nutrients digestibility were 68.61, 73.19, 70.46,
71.56,69.55 and 72.68% forDM; 71.58, 76.32, 74.31, 74.16, 73.00
and 74.95% for OM; 68.69, 69.82, 70.26, 72.22, 71.37 and 67.55%
for CP; 41.26, 54.03, 46.23, 41.73, 51.75 and 49.69% for CF; 85.75,
83.48,90.01,83.49, 75.90 and 85.76% for EE and 78.95,81.33,
79.85, 78.56, 78.11 and 80.00% for NFE, for Rl(UDCSC),
R2(UDCSC+U), R3(LSM),R4(LSM+U), R5(SFM) and R6(SFM+U),
respectively.
Concerningthe unsupplementedrations (with no U), RI(UDCSC)
showed the lowest digestibility values for most feed nutrients,
whereas, R3(LSM) recorded almost the highest ones. The differences
in digestibility values due to protein source effect were mostly not
significant
Regarding the supplemented rations, R2(UDCSC+U) had higher
digestibility values for all feed nutrients compared with those of
RI(UDCSC), except for EE digestibility. The differences in
digestibility values due to U supplementation of UDCSC were
significant (P< 0.05), for DM, OM and CF digestibility. Similar, SFM
supplemented with U(R6) showed higher digestion coefficients for
different nutrients compared to those of unsupplemented one (R 5)
except for CP and CF coefficients, but the differences were not
significant except for EE digestibility. In contrast, R4(USM+U) had
lower digestibility values for all approximate components than those
of R3(LSM), except for DM and CP digestibility values with no
significant differences due to U supplementation (except EE
digestibility).
2- Average feeding values were 59.61, 65.53, 63.41, 65.52, 60.91 and
64.67% as SV; 66.72, 71.78, 70.18, 70.59, 67.99 and 70.52% as TDN;
9.00,9.17,9.36, 10.11,9.29 and 9.04% as DCP and 6.42,6.86,
6.48, 5.98, 6.34 and 6.80 as NR for R [, R2, R3, R4, R5 and R6,
respectively.
R,(UDCSC) had the lowest SV, TDN and DCP values, among the
unsupplemented rations (R 1 , R3 and Rj ), while R3 (LSM) showed the
highest values. The differences in SV, TDN, DCP and NR values
between R, (SFM) and each of R I (UDCSC) and R3 (LSM) were not
significant. Whereas, the differences in SV and TDN values between
R](LSM) and Rl (UDCSC) were significant (R < 0.05).
Urea supplementation ofUDCSC ration, significantly (R < 0.05)
improved the SV, TDN and NR values. While, significant (R < 0.05)
improvement in DCP value was only observed when LSM containing
ration was supplemented with U.The same trend was observed for SV
and NR values for SFM containing ration supplemented with U(R 6)’
3- Nitrogen intake ranged between 20.46 g/d for lambs fed R 3 (LSM) and
22.81 g/d for those fed R6(SFM+U) with no significant differences
between all the experimental rations. Similarly, the differences in
nitrogen absorbed values were not significant, it ranged between
14.40 and 15.54 g/d. All groups of lambs showed positive nitrogen
balance values, it varied between 9.12 and 10.54 g/d without any
significant differences among all the experimental rations. Also, no
significant differences were detected between experimental rations for
nitrogen retained as ratios ofNB to N-intake and NB to N-absorbed.
The values ranged from 43.87 to 49.02% and 63.27 to 67.87%,
respectively.
4- The mean calculated microbial N production of the experimental
rations ranged from 8.00 to 9.3 g/d with no significant differences
among the experimental rations, indicating that neither protein source,
nor U supplementation had significant effect on microbial N
production.
5- At the first feeding period (42 days), lambs fed RI(UDCSC) and
R3(SFM) had higher final LBW, total and daily BWG values than
those fed R5 (SFM). In the same time, U supplementation of the
experimental rations (R2, UDCSC+U; R4, LSM+U and R6, SFM+U)
improved LBW, total and daily BWG values of lambs. Whereas,
throughout the second (42 days) and third (42 days) periods of the
feeding trial, lambs fed on R5(SFM) recorded higher LBW, total and
daily BWG values than those fed either Rl(UDCSC) or R3(LSM).
Urea supplementation of rations containing UDCSC and LSM (R2
and R4) improved the growth performance traits of lambs, while a
reverse trend was observed with the ration containing SFM (R ) 6 .
Results of the over all feeding period (126 days) affirmed the findings
of the second and third feeding periods, as R5 showed the best growth
performance values and U supplementation of UDCSC and LSM
rations (R2 and R4) slightly improved the growth performance of
lambs. However, the protein source and U supplementation had no
significant effect on the total and daily BWG values during all the
experimental periods.
6- The average daily feed intake as kg DM, SV, TDN and DCP for
lambs fed rations, R 1(UDCSC), R3 (LSM) and R 5(SFM) were nearly
similar. Values obtained varies between 0.762 and 0.792; 0.470 and
0.483; 0.526 and 0.536 and 0.071 and 0.074 Kg for DM, SV, TDN
and DCP intake, respectively. Urea supplementation ofUDCSC and
LSM rations (R2 and R4) caused an increase in average daily feed
intake as Kg DM, SV, TDN and DCP by 3.30, 13.62, 11.22 and
5.63% for R2 and 1.05,4.55, 1.68 and 9.86% for R4, respectively.
Whereas, supplementation of SFM with U(R6) decreased DM and
DCP intake oflambs by 2.46 and 5.71% and increased SV and TDN
intake by 3.73 and 1.68% , respectively.
7- Lambs fed R5(SFM) tended to have slightly higher feed efficiency
values (Kg gain/Kg DM; Kg gain/Kg SV; Kg gain/Kg TDN and Kg
gain/Kg DCP) than those for lambs fed either R1 (UDCSC) or
R3(LSM). Urea supplementation improved the feed efficiency values
as Kg gain/Kg DM, SV, TDN and DCP by 14.71,4.39,6.90 and
12.34% for UDCSC ration (Rz) and 15.65, 11.64, 15.31 and 6.47%
for LSM ration (R4), respectively. While, SFM supplemented with
U(R6) decreased the feed efficiency values as Kg gain/Kg DM, SV
and TDN by 2.78,9.46 and 6.86%, respectively, whereas values for
Kg gain/Kg DCP were similar for unsupp1emented and U
supplemented SFM rations (R, and R6). The effect of protein source
and U supplementation of the experimental rations on feed efficiency
values were always not significant.
8- Rs(SFM) recorded the lowest feed cost/Kg BWG value (3.444 LE)
among the three protein sources used in this study, while R [(UDCSC)
and R3(LSM) showed almost the same values being 3.897 and 3.884
LE, respectively. Urea supplementation ofUDCSC(R2) decreased
feed cost/Kg BWG value by about 16.99% compared with the
unsupplemented UDCSC(R [). Also, Rj(LSM+U) decreased feed
cost/Kg BWG value by about 20.58% compared with the unsupplemented
LSM (R3). In case of SFM a reverse trend was observed as
U supplementation of SFM (R 6) increased the feed costlKg BWG
value by 3.60%. Rations recorded the lowest feed cost/Kg BWG
values, achieved the highest (best) economic efficiency values.
Rs(SFM) showed the best economic feed efficiency value (2.179)
compared with those shown by Rl(UDCSC) and R3(LSM) being,
1.926 and 1.931, respectively. R2(UDCSC+U) and R4 (LSM+U)
showed better economic feed efficiency values compared with the
unsupplemented ones (2.253 vs 1.926 for UDCSC rations and 2.329
vs 1.931 for LSM rations), whereas, values for SFM unsupplemented
or supplemented with U were nearly similar, being 2.179 and 2.104,
respectively.
9- The minimum pH values throughout all the different periods of the
feeding trial were observed at 3 hrs post feeding and tended to
increase after that at 6 hrs post feeding. In the meantime,
R2(UDCSC+U)showed lower pH values than R I(UDCSC) during all
the feeding trial periods, but the differences in pH values due to urea
supplementation ofUDCSC were not significant except after 3 hrs
and 6 hrs of feeding at the end of the feeding trial (18 weeks). The
effect of urea supplementation of LSM and SFM rations as well as
nitrogen source (R I, R3 andRs) had no clear trend on pH values at all
periods studied, and the differences were always not significant.
10-The NH 3-N concentration was minimum before feeding, increased to
its maximum level at 3 hrs post feeding, then tended to decline at 6
hrs post feeding during all the feeding trial periods (after 2, 9 and 18
weeks). However, the differences in NH3-N concentration due to
protein source effect at all periods of the trial were almost not
significant. Urea supplementation of protein sources tested in this
study increased the ruminal NH 3-N concentration throughout the
different periods of the feeding trial, except for LSM ration (R4) after
2 and 9 weeks. The improvement in NH3-N concentration due to the
supplementation was significant (P < 0.05) only with R4 at the end of
the feeding trial and R6 after 9 and end of the feeding trial (18 weeks).
ll-Ruminal TVF A’s concentration reached the highest level after 3 hrs
post feeding after which it declined at 6 hrs post feeding. The
differences in TVF A’s due to protein source effect were always not
significant. Urea supplementation caused an increase in rumen
TVFA’s concentration at all periods studied, but the effect of urea
supplementation on TVFA’s concentration were not significant except
for R[ (UDCSC) and R3(LSM), both at the termination of the feeding
trial.
12-The molar proportions of individual VFA’s and acetic to propionic
acid ratio had no clear trend either for sampling time, nitrogen source
or U supplementation. The differences in molar proportions of
individual VFA’s and acetic to propionic acid ratios due to nitrogen
source or U supplementation effects were almost non-significant.
13- Values of all blood parameters obtained in this study be in normal
ranges reported in the literature and indicate a normal kidney
function.
Results of blood parameters showed that protein source (UDCSC,
LSM or SFM) and U supplementation had no significant effect on urea,
total protein, albumin, globulin concentrations and albumin: globulin
ratio in blood plasma of lams during different periods of the feeding trial.