Ciência e Tecnologia Veterinária

Studies on the Effects of Substituting Soya Bean Meal (SBM) with Blood Meal (BM) on External Eostrus Signs and Hormonal Profile of Gilts

Abstract

Abonyi Festus Otaka, Omeke Benjamin Chigozie O and Marire Benjamin N

This study was conducted to evaluate the effects on external eostrus signs and hormonal profile of pigs reared with feed formulated by subtitling soya bean meal (SBM) with blood meal (BM). Blood, used to formulate the experimental diets was collected from apparently healthy cattle at slaughter, boiled and sun dried. Thereafter, the BM was used to formulate four grower pig diets: A, B, C and D, containing 50.0, 75.0, 100.0 and 0.0% (control) SBM as replacement for BM. Following feed formulation, 16 Landrace×Large White crossbred weanling pigs were selected and used for the study. They were aged 6.0 to 6.5 weeks, with average body weight of 12.24 kg. The pigs were randomly allotted to the 4 treatment groups, each of which was further divided into two; with 2 pigs as replicate. Individual animal was maintained on experimental diet that was equivalent to 5.0% of its average body
weight as ration from beginning to the end of study. At their 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, respectively. Similarly on their forth eostrus cycle, the gilts were bled every 30 min for 6 hours and sera obtained was used to determine their hormonal profile. Hormone assay was done by ELISA technique. Results showed no dietary treatment affected most of the parameters investigated within the study period. Thus, 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) variation, when compared to the control. The study showed that while the duration of standing reflex increased, intensity and duration of reddening and swelling of vulva rather decreased with eostrus cycle number. The hormonal assay showed that estradiol-17β levels of groups A, B and C were significantly (P<0.05) higher than the control group D animals. BM inclusion had no significant effect on Luteinizing and Follicle Stimulating Hormonal profile of the gilts, but their pulsatile release at the 3rd and 6th hours was evident. It is concluded that inclusion of BM in formulating pig diets under tropical humid conditions is safe. It does not interfere with some key reproductive parameters in gilts, such as their age at puberty, manifestation of eostrus signs and reproductive hormonal profile.