An experiment was conducted to investigate the effect of concentrations of certain blood nutrientsensitive metabolites and the resumption of postpartum ovarian cyclicity in 16 Sanga cows (mean BCS 5). Blood samples were taken from cows from weeks 1 to 13 (90 days) postpartum, processed and the plasma progesterone concentration measured to determine the resumption of postpartum ovarian cyclicity. The cows were classified as having resumed ovarian cyclicity when a plasma progesterone concentration of ≥1.0 ng/mL was recorded for two consecutive weekly samples. Based on the resumption of ovarian activity, cows were classified as early cycling, late cycling or non-cycling. The plasma glucose, cholesterol, total protein, albumin and globulin concentrations recorded were similar in the early cycling, late cycling and non-cycling cows. The mean blood glucose, cholesterol, total protein, albumin and globulin concentrations were 3.60 mmol/L, 2.47 mmol/L, 83.1 g/L, 29.9 g/L and 52.9 g/L, respectively. Plasma urea concentrations in late (6.57 ± 0.17 mmol/L) and non-cycling (6.59 ± 0.17 mmol/L) cows were higher than in the early cycling (5.99 ± 0.17 mmol/L) cows in weeks 1 to 13 postpartum. In addition, the plasma creatinine concentration in the early cycling cows was higher than in late cycling cows (101.8 ± 1.82 versus 94.0 ± 1.99 mmol/L). Cows with higher plasma concentrations of urea and lower creatinine concentrations were at risk of delayed resumption of postpartum ovarian cyclicity. Results suggest poor nutritional status, especially energy deficiency, as a major underlying factor suppressing the postpartum resumption of ovarian cyclicity.

No abstract

The physiological basis of seasonal breeding in the guinea fowl (Numida meleagris) still remains unknown, despite the socioeconomic importance of these birds, particularly in Ghana. A study involving a total of 50 local guinea cocks was conducted, and documented gross anatomical and histological differences in the reproductive organs of breeding and non-breeding male guinea fowls. The study also compared peripheral testosterone concentrations in breeding and non-breeding cocks. Seasonal differences in variables measured were determined using two-tailed t-test/Mann-Whitney U-test. All comparisons were made at 5% level of significance. Breeding males had significantly (P = 0.000) higher anatomical biometric parameters than their non-breeding counterparts. Also, breeding birds had thicker (P = 0.000) phalli than their non-breeding counterparts. Histologically, regressing testis was characterized by the presence of sloughed off cells and increased debris in the tubular lumen and within the excurrent duct system, collapsed tubules and reduction in tubular lumen. Germ and Sertoli cell populations and nuclear diameters and actual seminiferous tubular diameter and length in regressing testes were significantly (P = 0.000) lower than in active testes. Leydig cell nuclear diameters and populations were also significantly (P = 0.000) reduced. Relative volume of seminiferous tubules in the testis, testicular sperm production/mg testis and per testis and peripheral testosterone concentrations were all higher (P < 0.05) in breeding than non-breeding testis. The ducts in the epididymal region also saw significant (P < 0.05) reductions in luminal diameters in non-breeding birds. Significant regression in anatomical and histological structures of the guinea cock reproductive tract occurred during the non-breeding season, and lower peripheral testosterone concentrations may be responsible for this phenomenon.

These experiments were conducted to determine if 1) syndyphalin-33 (SD33), a mu-opioid receptor ligand, affects feed intake; 2) SD33 effects on feed intake are mediated by actions on opioid receptors; and 3) its activity can counteract the reduction in feed intake associated with administration of bacterial endotoxin. In Exp. 1, 5 mixed-breed, castrate male sheep were housed indoors in individual pens. Animals had ad libitum access to water and concentrate feed. Saline (SAL; 0.9% NaCl) or SD33 (0.05 or 0.1 micromol/kg of BW) was injected i.v., and feed intake was determined at 2, 4, 6, 8, 24, and 48 h after the i.v. injections. Both doses of SD33 increased (at least P < 0.01) feed intake at 48 h relative to saline. In Exp. 2, SAL + SAL, SAL + SD33 (0.1 micromol/kg of BW), naloxone (NAL; 1 mg/kg of BW) + SAL, and NAL + SD33 were injected i.v. Food intake was determined as in Exp. 1. The SAL + SD33 treatment increased (P = 0.022) feed intake at 48 h relative to SAL + SAL. The NAL + SAL treatment reduced (at least P < 0.01) feed intake at 4, 6, 8, 24, and 48 h, whereas the combination of NAL and SD33 did not reduce feed intake at 24 (P = 0.969) or 48 h (P = 0.076) relative to the saline-treated sheep. In Exp. 3, sheep received 1 of 4 treatments: SAL + SAL, SAL + 0.1 micromol of SD33/kg of BW, 0.1 microg of lipopolysaccharide (LPS)/kg of BW + SAL, or LPS + SD33, and feed intake was monitored as in Exp. 1. Lipopolysaccharide suppressed cumulative feed intake for 48 h (P < 0.01) relative to saline control, but SD33 failed to reverse the reduction in feed intake during this period. These data indicate that SD33 increases feed intake in sheep after i.v. injection, and its effects are mediated via opioid receptors. However, the LPS-induced suppression in feed intake cannot be overcome by the opioid receptor ligand, SD33.

No abstract

Despite the potentials and contributions of guinea fowls to economic and social life in Ghana, accurate sex identification in these birds is still a major problem. Three hundred and sixty guinea fowls (180 birds per sex) were used in determining a more accurate and farmer friendly sexing technique. The sexing methods explored were vent, biometric, and molecular techniques. Vent sexing was accomplished by measuring phalli in 28 and 32-week-old birds, while biometric sexing involved the measurement of morphometric traits and data analyzed using discriminant function analysis. Molecular sexing was carried out by DNA extraction and subsequent PCR using the 2550F/2718R primer set. Females had a wider (P<0.05) pelvic inlet than male birds from first week of age until the end of the study, while the opposite was true for wattle length. However, wattle length differed (P<0.05) between both sexes after 4 weeks of age. Combining the biometric variables in a discriminant function, males could be distinguished from females with an accuracy of 94%. During molecular sexing, the P2/P8 primer set was not effective in sexing guinea fowls because it amplified a single band in both sexes and in the same manner. The sex of guinea fowls was properly determined using the primer set 2550F/2718R. Females produced 2 bands of 396 bp and 344 bp, while males only produced the larger band. Phallus size in the 2 sexes were distinguishable from 8 weeks of age, with males having longer and thicker (P<0.05) phalli than their female counterparts. Combining the 2 variables in a discriminate function, males and females could be distinguished with 98.3% accuracy. While the molecular method remains the most accurate sexing technique, the biometric method emerged as the most farmer friendly approach to sexing guinea fowls.

An experiment was conducted to investigate the effect of plasma concentrations of the metabolic hormones [Growth hormone (GH), insulin and insulin-like growth factor -I (IGF-I)] and nutritional metabolites (Glucose, cholesterol, total protein, albumin, globulin, urea and creatinine) on the resumption of post-partum ovarian activity in sixteen Friesian-Sanga cows grazing extensively on native grassland. Blood samples were taken from cows from week 1 to 16 post-partum. Cows were classified as having resumed ovarian activity when a plasma progesterone concentration of ≥ 1.0 ng/ml was recorded for two consecutive weekly samples. Based on the resumption of ovarian activity, cows were classified as early-cycling, late-cycling or non-cycling. The concentrations of the metabolic hormones were measured from week 1 to 10, while those of the nutritional metabolites were measured during week 1, 3, 5, 7 and 9 during the study period. The concentrations of the metabolic hormones, GH and insulin were similar (p > 0.05) in the three ovarian activity groups, likewise the concentrations of the nutritional metabolites, glucose, total protein, globulin, urea and creatinine. Plasma IGF-I concentration was higher (p < 0.001) in early-cycling (18.7 ± 0.74 ng/ml) than in late-cycling (12.4 ± 0.75 ng/ml) and non-cycling (10.4 ± 0.91 ng/ml) cows. Plasma cholesterol concentrations were significantly lower (p < 0.05) in early-cycling (1.94 ± 0.15 mmol/l) compared with late-cycling (2.48 ± 0.12 mmol/l) and non-cycling (2.61 ± 0.11 mmol/l) cows. For plasma albumin concentrations, the levels recorded for early-cycling cows were higher (40.7 ± 2.85 g/l) than in late-cycling (34.4 ± 1.97 g/l) and non-cycling (33.6 ± 2.66) cows. The results suggest that cows with lower plasma concentrations of IGF-I and albumin, but higher plasma cholesterol concentrations were at risk of delayed resumption of post-partum ovarian activity.

The study documented gross anatomical and histological differences in the reproductive organs of 28 breeding and non-breeding female guinea fowls. Peripheral progesterone and 17β-oestradiol concentrations were also compared in breeding and non-breeding hens. In non-breeding females, all ovarian and oviducal gross anatomical features had significantly regressed. Histologically, some of the changes in a regressing oviduct include systematic changes in height and size of all epithelial cells in all regions of the duct, absence/sparse ciliation of portions of surface epithelium in the magnum, isthmian and uterine regions, general loss of cytoplasmic mass, reduction in size and degeneration of tubular glands. Mucosal folds in all regions of the oviduct except the infundibular lip were higher in breeding females. No difference was found between the two groups in plasma progesterone concentrations. Breeding females, however, had higher peripheral oestradiol concentrations than non-breeding females. About 2 h prior to oviposition, plasma oestradiol concentrations peaked at 2.4-fold (230 pg/ml) compared with baseline concentration and plasma progesterone concentrations by nearly 9-fold (5.29 ng/ml) of baseline. Significant regression and changes in the histological structure of the ovary and oviduct had occurred in non-breeding females, and lower peripheral oestrogen concentrations may be responsible for this phenomenon.