External Eostrus Signs, Hormonal Profile and Pre- Weaning Performance of FI Piglets of Pigs Fed Soya Bean Meal Replaced Blood Meal Diets

The focus of this study was to evaluate the effects of feeding pigs soya bean meal (SBM) replaced
blood meal (BM) diets on external eostrus signs, hormonal profile and pre-weaning performance of FI
piglets. Blood was collected from apparently healthy cattle at slaughter; boiled, sun dried and used to
formulate starter and finisher diets (T1, T2, T3 and T4). The diets contained 0.00 (T1, control), 50.00
(T2), 75.00 (T3) and 100.00% (T4) BM as replacement for SBM, respectively. Twenty four Landrace ×
Large White crossbred pigs with a mean weight of 12.24 kg and age range of 6.0 to 6.5 weeks were
randomly allotted to the four treatment groups. The pigs were maintained on their group specific diet
at 5.0% average body weight as ration until they were mated. At 6.5 months of age, the gilts were
observed two times daily for symptoms of eostrus. Following the manifestation of eostrus signs,
scoring for the vulva changes was carried out and values obtained were compared between treatment
groups at first, second and third eostrus cycles. On second day of forth eostrus cycle, one gilt from
each group (n=16) was randomly selected and bled every 30 min for 6 hours. The sera obtained was
used to determine hormonal profile using ELISA technique. After blood collection, the twenty four pigs
were crossed and fed 20.20, 2.00 and 2.50 kg feed per day at first, second and third stages of
gestation and additional 0.20 kg feed per piglet farrowed at lactation. Litter size, daily weight gain,
weaning size and weight of the FI offspring were determined. Results showed that age at puberty,
duration of standing reflex, intensity of reddening, and swelling of the vulva and eostrus cycle length
showed no significant (p > 0.05) difference to the control. Whereas duration of standing reflex
increased, intensity and duration of reddening and swelling of vulva rather decreased with eostrus
cycle number in all the groups. The hormonal assay showed that estradiol-17β levels of groups T2, T3
and T4 were significantly (p < 0.05) higher than the control. The BM inclusion had no significant (p >
0.05) effect on Luteinizing and Follicle Stimulating Hormonal profiles of the gilts, but pulsatile release
at the 3rd and 6th hours was evident. There was no significant (p > 0.05) difference in performance
indices of the F1piglets, although those fed 75% BM diet tended to have performed better than others.
It was concluded that inclusion of locally processed BM in pigs' diets under tropical humid conditions
is safe and does not interfere negatively with some key reproductive parameters of primigravid
crossbred pigs and pre-weaning performance of their F1 offspring.