EFFECT OF FEEDING LEVEL AND REPLACEMENT OF NIGELLA SATIVA MEAL IN DIET OF RAHMANI EWE LAMBS ON: 2. ONSET OF PUBERTY, OESTROUS ACTIVITY AND CONCEPTION RATE

SUMMARY
Influence of level of feeding (80% or 100 of NRC, 1985 allowance) and
substituting CFM protein by NSM protein at the rate of 50% at the two tested levels
on reproductive performance of Rahmani ewe lambs was studied. Forty Rahmani
ewe lambs aged 62.25±1.1days and weighed 14.8±0.4 kg were divided into four
comparable groups according to live body weight and age, 10 ewe lambs in each.
Ewe lambs were used in this study as follows: The 1st group (G1), ewe lambs
received 80% of NRC (1985) allowance of crude protein (CP) based on LBW for
early weaned lambs up to 30 kg LBW, then, the requirements were changed for
replacement ewe lambs up to the end of the experiment. The 2nd group (G2), ewe
lambs received as that in (G1), but 50% CFM protein was replaced by NSM
protein. The 3rd group (G3), ewe lambs received 100% of NRC (1985) allowance of
the same roughage: concentrate ratio (40:60, R: C). The 4th group (G4), ewe lambs
received as that in (G3), but 50% CFM protein was replaced by NSM protein. Daily
oestrous observation was started at 5 months of age to detect age and weight at
puberty. Also, LBW at mating and conception were recorded. Results indicted
similar effect of CP level and NSM, on puberty and mating ages. All ewe lambs
(100%) fed 80% CP level or diets with NSM came in oestros up to yearling
compared with 94.4% in those fed 100% CP level or diets without NSM. Only one
animal of each ewe lambs fed 100% CP (5.6%) or diets without NSM (5.3%) which
did not exhibit oestros up to yearling showed oestrous behavior after yearling.. All
ewe lambs (100%) fed 80% CP with or without NSM and those fed 100% with
NSM showed oestros up to yearling as compared to 88.9% in those fed 100%
without NSM up to yearling. Oestrous duration was insignificantly longer in ewe
lambs fed 80% than those fed 100% CP. Feeding ewe lambs on diet with NSM did
not affect oestrous duration, but slightly increased short duration and decreased the
normal one. Ewe lambs fed 80% without NSM showed the longest duration with
high distribution of normal type of duration. Feeding ewe lambs on 80% CP or diet
without NSM insignificantly increased oestrous duration compared with those fed
100% CP or diet with NSM. Average length of oestrous cycle was about 18 days
was not affected by CP level or NSM, being almost within the normal type between
17.44 and 19.61days. The highest normal cycles were recorded in ewe lambs fed
80% CP with NSM (75%) and the lowest were in those fed 100% CP with or
without NSM (50%). Occurrence of the 1st oestrus was nearly similar in ewe lambs
fed different dietary treatments. Percentages of mated ewe lambs fed 80% CP
(94.1%) or diets without NSM (93.3%) were higher than those fed 100% CP
(85.7%) or diets with NSM (87.5%) up to yearling. The opposite was observed after
yearling. The percentages of mated ewe lambs were associated with lower
percentages of oestrous incidence as affected by experimental diets. Lower
conception rate (CR) was recorded for ewe lambs, being almost slightly lower for
ewe lambs fed 80% CP or diets with NSM (76.5 and 75%) than those fed 100% CP
(78.6%) or diets without NSM.
It could be concluded that feeding Rahmani ewe lambs on 80% dietary CP or
diets with or without 50% replacement of CFM by NSM proteins had beneficial
effect on oestrous activity in terms of length of oestrous cycle and oestrous duration
as well as on conception rate.