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Articles by N.P. Chiezey
Total Records ( 7 ) for N.P. Chiezey
  N.P. Chiezey , O.J. Ajanusi and E.O. Oyedipe
  Reproductive performance of a flock of 63 ewes carrying natural infections of gastrointestinal worm burdens was studied. Parameters monitored included: ovarian activity through progesterone profiles, parturition intervals, birth weights, mortality rates of offspring and worm burdens through faecal egg counts. Mean lamb birth weight was 2.6±0.48, litter size was 1.1 lambs and up to 50% of the ewes lambed two or more times within the 18 month period. Twining rate was 6%, with 4.5% abortions and a mortality rate of 37% up to three months of age. There were significantly less lambs born in the late wet season, than any other season, lambing percentages being 9.9, 23.3, 25.9 and 38% for the late wet, late dry, early wet and early dry seasons, respectively. Mean lambing intervals was 192±7.5 days in 17% of ewes and 220±10.4 days in another 34.8% of the animals. The remaining 47.8% had mean LI of between 250-349 days. EPG was significantly lower (p<0.05) in ewes with mean LI of 192 days (5025EPG) but was not significantly different in ewes with longer LI. EPG ranged from 13011 to 16317 in these groups. Progesterone profiles showed that long lambing intervals was due to delayed resumption of ovarian activity post partum. In addition to seasonal variation in availability of quantity and quality of feed, helminthosis may have an effect on reproductive efficiency in sheep, mediated mainly through effects on body condition which ultimately affects re-breeding intervals.
  T.A. Dare , P.I. Rekwot , Y.O. Aliu , M. Mamman , J.A. Obidi , N.P. Chiezey and B.O. Omontese
  The effect of season and Progesterone-Releasing Intravaginal Device (PRID) alone or with Pregnant Mare Serum Gonadotropin (PMSG) on ovarian function of 106 Bunaji cows was investigated in two seasons. In the dry season trial, 46 cows were randomly distributed into the following treatment groups: PRID alone (n = 16), PRID+PMSG (n = 15) and control (15). In the rainy season trial, 60 cows were randomly distributed into the following treatment groups: PRID alone (n = 20); PRID+PMSG (n = 20) and control (20). During the dry season, Bunaji cows treated with PRID alone had a significantly (p<0.05) lower estrus response than the cows administered with PRID+PMSG (37.5 vs 66.7%, respectively). During the rainy season, 65.0% of Bunaji cows treated with PRID+PMSG were found to be in estrus; this was not significantly higher than the value of 60.0% estrus rate recorded in Bunaji cows treated with PRID only. In PRID treated Bunaji cows, pregnancy rates of 25.0 and 45.0% was recorded during the dry and rainy season, respectively. Pregnancy rates in PRID+PMSG treated cows were 46.7 and 50.0%, respectively. Pregnancy rate was generally lower in the dry season than in the rainy season in both PRID only, PRID+PMSG and control groups. However, the highest pregnancy rate of 50.0% was obtained in PRID+PMSG treated Bunaji cows during the rainy season. Conception rate in Bunaji cows treated with PRID only (66.7%) was lower than cows treated with PRID+PMSG (70%) during the dry season although not significantly. Similarly during the rainy season, Bunaji cows treated with PRID+PMSG had a higher conception rate than cows treated with PRID only (76.9 vs 75.0%, respectively). This study suggests that the rainy season enhances greater ovarian function in dairy cows in the Northern Guinea Savannah zone of Nigeria and that administration of PMSG may potentiate fertility rates.
  B.O. Omontese , P.I. Rekwot , H.J. Makun , J.A. Obidi , J.S. Ruwaan and N.P. Chiezey
  The efficiency of EAZI-Breed™ CIDR® and FGA-30® intravaginal sponges in synchronizing estrus was investigated in prepartum Yankasa Ewes. About 20 randomly cycling pre-partum Yankasa ewes aged between 1.5-2 years and weighing between 13-15 kg was used for this study. They were randomly assigned into two groups, Group A (FGA, n = 10) and Group B (CIDR®, n = 10) for 14 days. Natural mating by a fertile ram was performed following progestagen withdrawal for ewes detected to be on heat. Estrus response in Group A and B was 70 and 80%, respectively. The time to estrus onset following progestagen withdrawal for FGA-30 and CIDR (Mean±SEM) was 43.60±6.98 and 23.57±4.07 h, respectively. In Groups A and B, the duration of induced estrus was (46.65±3.08 and 53.90±5.87 h) while estrus cessation was (90.37±8.44 and 77.92±4.24 h) post withdrawal of the devices. The interval from withdrawal of progestagen to onset of estrus was (p<0.05) longer in FGA than in CIDR (43.60±6.98 vs. 23.57±4.07 h). However, the duration of induced estrus period was shorter in the FGA group than the CIDR group. Retention rate was lower in group A (60%) than B (90%). Drawstring breakage observed in FGA sponges was absent in CIDR devices (20% versus 0) while vaginal discharge rate was higher in group A. These results show that although FGA and CIDR devices are equally efficient in synchronizing estrus in prepartum Yankasa ewes, CIDR provides higher estrus response rate, shorter time to estrus, longer duration of estrus, higher retention rate and ease of application. Consequently, the use of CIDR is recommended.
  T.A. Dare , P.I. Rekwot , Y.O. Aliu , M. Mamman , J.A. Obidi , B.O. Omontese , N.P. Chiezey and J.S. Rwuann
  The effect of season and Progesterone-Releasing Intravaginal Device (PRID) alone or with Pregnant Mare Serum Gonadotropin (PMSG) on ovarian function of 106 Bunaji cows was investigated in two seasons. In the dry season trial, 46 cows were randomly distributed into the following treatment groups: PRID alone (n = 16), PRID+PMSG (n = 15) and control (15). In the rainy season trial, 60 cows were randomly distributed into the following treatment groups: PRID alone (n = 20); PRID+PMSG (n = 20) and control (20). During the dry season, Bunaji cows treated with PRID alone had a significantly (p<0.05) lower estrus response than the cows administered with PRID+PMSG (37.5 vs 66.7%, respectively). During the rainy season, 65.0% of Bunaji cows treated with PRID+PMSG were found to be in estrus; this was not significantly higher than the value of 60.0% estrus rate recorded in Bunaji cows treated with PRID only. In PRID treated Bunaji cows, pregnancy rates of 25.0 and 45.0% was recorded during the dry and rainy season, respectively. Pregnancy rates in PRID+PMSG treated cows were 46.7 and 50.0%, respectively. Pregnancy rate was generally lower in the dry season than in the rainy season in both PRID only, PRID+PMSG and control groups. However, the highest pregnancy rate of 50.0% was obtained in PRID+PMSG treated Bunaji cows during the rainy season. Conception rate in Bunaji cows treated with PRID only (66.7%) was lower than cows treated with PRID+PMSG (70%) during the dry season, although not significantly. Similarly during the rainy season, Bunaji cows treated with PRID+PMSG had a higher conception rate than cows treated with PRID only (76.9 vs 75.0%, respectively). In conclusion, this study suggests that the rainy season enhances greater ovarian function in dairy cows in the Northern Guinea Savannah zone of Nigeria and that administration of PMSG may potentiate fertility rates.
  N.P. Chiezey and E.O. Oyedipe
  The aim of this study was to evaluate the influence of different levels of H. contortus infections on parasitological and some haematological parameters in Nigerian Yankasa sheep as a basis for further genetic studies. Forty seven Yankasa rams were divided into 3 infected groups (n = 12) the fourth group (n = 11) served as control. The animals were infected with trickle infections of third stage larvae which totaled 35,000, 14,000 and 2800 for groups 1, 2 and 3, respectively. Faecal Egg Count (FEC), blood Packed Cell Volume (PCV), Peripheral Eosinophil (PE) response and Worm Burden (WB) at necropsy were used to assess resistance, over a 21 week period. The mean establishment rate decreased with increasing infection dose, being less than 2% of the infective larval doses, although there was wide individual variability in the response to infections irrespective of dose given. Thirty two percent of animals succumbed to infection in the first 4 weeks and these were regarded as susceptible animals and they had high FEC values (10,880-22,280), sharp decreases in PCV and low eosinophilic values compared to animals that survived to the end of the experiment. Surviving animals were refractory to the infections as shown by a delayed prepatent period (up to 49 days), low helminth egg output (626-1172 EPG) and low mean worm burden (44-357). There was negative correlation between FEC and PCV (r = -0.29) which was significant (p<0.05) and also a negative but insignificant correlation between FEC and PE (r = -0.09). These variable responses are indicative of acquired immunological responsiveness and resistance to infection with H. contortus which could be exploited to reduce production losses.
  J.S. Ruwaan , P.I. Rekwot , P.A. Abdu , B.O. Omontese , J.A. Obidi and N.P. Chiezey
  About fifty 20 weeks old Shika Brown (SB) cocks were used in this study. Five cocks consisting of three Red Shika-Brown (RSB) and two White Shika-Brown (WSB) were bled for serum samples for testosterone assay at weeks 1, 3 and 6 pre and post-infection with a Velogenic Newcastle disease virus. Blood samples were collected at 30 min interval for 3 h from each cock on the days of sampling. The blood samples were centrifuged in a Hermle Z364 centrifuge at 251.6x g for 15 min with the sera obtained stored in serum vials and kept in a deep freezer at -20°C until analysis using the Enzyme Linked Immunosorbent Assay (ELISA) technique. At the end of the study, twenty control (n = 20) and twenty infected (n = 20) cocks were slaughtered. Their testicles were removed, measured, minced and ground for the determination of gonadal sperm reserves. The mean testosterone concentration of both the control SB cocks and the pre-infected SB cocks had no particular pattern. The mean testosterone concentration post infection showed a decrease from week 1-6. The mean testosterone concentration peak for the control red SB cocks was 1, 2 and 2.5 nmols mL-1 at weeks 1, 3 and 6, respectively while the white SB cocks had 12.5, 5.5, 3 nmols mL-1 at weeks 1, 3 and 6, respectively. The infected red SB cocks had mean testosterone concentration peaks of 9.7, 6.3 and 2.7 nmols mL-1 at weeks 1, 3 and 6 post-infection, respectively while the white SB cocks had a mean testosterone concentration peak of 6.5, 14.5 and 6.5 nmols mL-1 at weeks 1, 3 and 6 post-infection, respectively. The gonadal sperm reserves of the control red and white SB cocks were not significantly different but the gonadal sperm reserves of the control white SB cocks was significantly (p>0.05) higher than the gonadal sperm reserves of the infected red and white SB cocks. The total gonadal sperm reserve of the control white cocks was significantly (p>0.05) higher than the total gonadal sperm reserves of the infected red and white SB cocks.
  B.O. Omontese , P.I. Rekwot , H.J. Makun , J.A. Obidi , J.S. Rwuaan and N.P. Chiezey
  The efficiency of EAZI-Breed™ CIDR® and FGA-30® intravaginal sponges in synchronizing estrus was investigated in prepartum Red Sokoto does. About 19 randomly cycling pre-partum Red Sokoto does aged between 1.5-2 years and weighing between 12-14 kg were used for this study. They were randomly assigned into two groups, Group A (FGA, n = 10) and Group B (CIDR®, n = 9) for 21 days. Natural mating was performed following progestagen withdrawal for animals detected to be on heat. Estrus response was 20 and 55.6% in groups A and B, respectively. The time to estrus onset following progestagen withdrawal for FGA and CIDR (Mean±S.D.) was 93.09±2.06 and 50.29±4.71 h; duration of induced estrus (0.08±0.05 and 39.99±6.05 h) while estrus cessation was (93.14±2.03 and 90.48±4.69 h) in group A and B, respectively. Interval between withdrawal of progestagen and onset of estrus was significantly (p<0.05) longer in FGA compared to CIDR. The duration of induced estrus period was significantly (p<0.05) longer in CIDR treatment. Retention rate was 100% (FGA) and 88.9% (CIDR) in group A and B, respectively. Drawstring breakage was observed in FGA sponges but absent in CIDR devices. Also, vaginal discharge rate was higher in FGA than CIDR groups. These results show that CIDR devices are more efficient in synchronizing estrus in prepartum Red Sokoto does. This is because CIDR provides higher estrus response rate, shorter time to estrus, longer duration of estrus, absence of drawstring breakage and better ease of application. Therefore, the use of CIDR is advocated.
 
 
 
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