Effect of plant spacing and nitrogen fertilizer levels on the growth,dry‐matter yield and nutritive quality of Columbus grass (Sorghum almum stapf) in southwest Nigeria

A field experiment was conducted in 2006 and 2007 to determine the agronomic performance and nutritive value of Sorghum almum for introduction in the derived savannah area of Nigeria. The experiment was arranged in a 2 × 4 factorial design with 2 plant spacings (0·5 × 0·5 m and 1·0 × 1·0 m) and 4 nitrogen (N) fertilizer levels (0, 60, 120 and 180 kg N ha^?1). Plant height, tiller number, leaf proportion, biomass yield and nutritive value of the herbage were evaluated as part of the search for alternatives (especially drought tolerant) to local forages for dry season feeding of ruminants. Herbage yield data were tested for linear, quadratic and cubic trends to identify the optimal fertilizer levels for both spacings. Spacing × N interactions (P < 0·05) were observed for plant height and tiller number in both years. Agronomic performance was marginally better in 2007 compared with 2006. The maximum dry‐matter (DM) yield of 3500 and 3740 kg ha^?1 for the more dense row spacing (0·5 × 0·5 m) was achieved at N fertilizer levels of 144 and 149 kg N ha^?1 for 2006 and 2007 respectively. For the less dense (1·0 × 1·0 m) row spacing, the maximum DM yield of 3020 and 3240 kg ha^?1 was achieved at 51 and 97 kg N ha^?1 for 2006 and 2007 respectively. The crude protein content of the grass ranged from 61 to 89 g kg^?1 DM, while the neutral detergent fibre (NDF) content ranged from 700 to 734 g kg^?1 DM. The ability of S. almum to persist into the second year in this region is seen as a promising index as persistence is one of the characteristics of a good forage plant. Considering the exorbitant price of N fertilizer, less dense row spacing with N fertilizer rate in the range of 50–100 kg N ha^?1 is hereby recommended for this region.     

Chemical composition and nutritive value of four varieties of cassava leaves grown in South-Western Nigeria

The nutritive value of leaves of four varieties of cassava - MS 6, TMS 30555, Idileruwa and TMS 30572 was evaluated based on their chemical composition and in vitro fermentation. Crude protein (CP) contents of cassava leaves ranged from 177 to 240 g/kg dry matter (DM), with TMS 30555 showing the highest CP contents. Neutral detergent fibre (NDFom) and acid detergent fibre (ADFom) contents of cassava leaves ranged from 596 to 662 and 418 to 546 g/kg DM respectively. Condensed tannin (CT) and hydrocyanic acid contents ranged from 1.0 to 3.8 g/kg and 58.5 to 86.7 mg/kg DM respectively. The range of volatile fatty acids (VFA) in the supernatant after in vitro incubation of the cassava varieties was: acetate (14.7-31.5 mmol/l); propionate (4.5-6.3 mmol/l); butyrate (3.1-3.9 mmol/l); valerate (0.4-0.6 mmol/l); iso-butyrate (0.6-1.3 mmol/l); iso-valerate (1.1-1.9 mmol/l). The acetate:propionate ratio resulting from fermentation of TMS 30555 was higher(p < 0.05) than that of the other leaves. The highest in vitro gas production of 50.5 ml/200 mg DM was recorded for MS6 being higher (p < 0.05) than for TMS 30572, but similar to TMS 30555 and Idileruwa. The DM, CP, ADF and HCN contents of cassava leaves were positively correlated with gas production, while CT content was negatively correlated with gas production. The study showed that leaves of the varieties MS 6 and TMS 30555 are superior to the others in terms of CP and gas production indicating a higher digestibility and energy content and thus nutritive potential. They may therefore serve as supplements for ruminants fed on poor roughages.     

Haematological and serum biochemical parameters of West African Dwarf goats fed dried cassava leaves-based concentrate diets

The study was conducted to investigate the effects of feeding different levels of dried cassava leaves at 0%, 20%, 40% and 60%, respectively, using guinea grass as basal feed, on the haematological and serum biochemical parameters of West African Dwarf (WAD) goats. The study lasted for 116 days during which haematological and serum biochemical parameters were monitored in 40 male goats before and after, using a completely randomized design. At the start of the experiment, packed cell volume (PCV) ranged from 21.5% to 25.5% while haemoglobin concentration (Hb) and RBC significantly (P < 0.01) ranged from 7.3 to 8.6 g/dl and 10.4 to 13.2 × 10¹²/l, respectively. White blood cells reduced significantly (P < 0.05)) from 16.4 to 11.7 × 10⁹/l) as dried cassava leaves increased in the diets. At the end of the trial, there was a slight increase in the values of PCV and Hb in the diets (P > 0.05). Lymphocyte reduced significantly (P < 0.05) from 50.0% to 63.5% in the diets. Neutrophils, however, increased (P > 0.05) at the 0% to 40% levels and reduced at the 60% level of dried cassava leaves inclusion. At the start of the experiment, values for glucose significantly (P < 0.05) ranged from 40.1 to 56.0 mg/dl. Total protein and albumin values ranged significantly (P < 0.05) from 56.0 to 68.5 g/dl and 30.6 to 38.4 g/dl, respectively. At the end of the experiment, serum creatinine increased significantly (P < 0.05) as the level of dried cassava leaves increased from 0% to 60% in the diets. The study revealed that inclusion of dried cassava leaves in the diets of West African Dwarf goats had no deleterious effects on the haematological and serum biochemical parameters of WAD goats and could therefore be included in ruminant diets up to 60%.     

Effect of dietary ascorbate fortification on lipolysis activity of juvenile black sea bream Acanthopagrus schlegeli

ABSTRACT:   Hatchery-reared black sea bream Acanthopagrus schlegeli juveniles averaging 0.05 g in body weight were fed either a control diet (commercial diet) or an experimental diet in which the commercial diet was fortified with 50 mg l -ascorbyl 2-monophosphate Mg (APM)/100 g diet for 50 days. Calcium ascorbate supplemented as a vitamin mixture in the control diet was completely destroyed during storage. Fortification with APM significantly increased the ascorbic acid levels in the muscle, liver, brain and eye. Although APM fortification did not influence growth, survival or fish body composition, adipocyte diameter in the intraperitoneal fat body (IPF) was significantly reduced. After the feeding experiment, the fish were kept for 39 days without feeding. Fortification with APM resulted in high survival, high muscle protein retention and low body weight loss. The results suggested the necessity of fortification with an adequate amount of ascorbate in the diet. While fatty acid compositions of the IPF, muscle and liver were not significantly influenced by APM fortification, characteristic changes in the fatty acid profile were found after starvation. Vitamin C and highly unsaturated fatty acids seemed crossly interactive in relation to lipolysis activity in black sea bream juveniles.     

Effects of urea-treated fibrous diets on nutrient intake, digestibility, performance and haematological parameters of Yankasa rams

An experiment was conducted to investigate the effects of urea-treated fibrous diets on the intake, nutrient digestibility, performance and haematological parameters of Yankasa rams. A total of 48 Yankasa rams (BW 10.00?±?1.50 kg; 6–8 months old) were allocated into four treatment groups in a completely randomised design (12 rams per treatment). Animals were placed on complete rations of yam peels, maize bran and rice husk treated with 0, 1.0, 1.5 or 2.0 % urea. The experiment lasted for 18 weeks. Yankasa rams fed with urea-treated diets had higher feed intake (949.88 and 938.04 g/day for U₁₅ and U₂₀, respectively), daily weight gain (227.67 and 181.00 g/day for U₁₅ and U₂₀, respectively) and better feed conversion ratio (4.17 and 5.18 for U₁₅ and U₂₀, respectively). Rams on urea-treated diets had higher haemoglobin and red blood cell contents and higher weight gains, indicating that urea treatment enhanced nutrient supply and utilisation at the tissue level. It was concluded that urea treatment of fibrous farm by-products is a promising feeding strategy especially during the dry season when there is scarcity of high-quality forages. Addition of 1.5 % urea to roughage diets and farm by-products to form a total mixed ration may preclude the search for supplements.     

Morphology of Dromedary Camel Oocytes and their Ability to Spontaneous and Chemical Parthenogenetic Activation

The present work was conducted to examine (1) the morphology of dromedary cumulus‐oocytes complexes (COCs), (2) to study the incidence of spontaneous development of oocytes in vivo and (3) to assess the ability of in vitro matured dromedary oocytes to chemical parthenogenetic activation compared with in vitro fertilized (IVF) oocytes. COCs were recovered from dromedary ovaries classified according to their morphology into six categories. Oocyte diameter was measured using eye piece micrometer. For chemical activation, COCs with at least three layers of cumulus‐cells were in vitro matured (IVM) in TCM 199 + 10 μg/ml FSH + 10 IU hCG/ml + 10% FCS + 50 μg/ml gentamycin. COCs were incubated for 40 h at 38.5°C under 5% CO₂ in humidified air. After IVM, matured oocytes with first polar body (first Pb) were divided into two groups. Group 1: activated in 7% ethanol (E) for 5 min followed by culture in 2 mM 6‐dimethylaminopurin (6‐DMAP, E D, subgroup 1) or 10 μg/ml cycloheximide (CHX, E CHX, subgroup 2) for 3.5 h at 38.5°C under 5% CO₂. In group 2, oocytes were activated using 50 μM Ca A23187 (Ca A) for 5 min followed by culture in 2 mM 6‐DMAP (Ca D, subgroup 3) or 10 μg/ml CHX(Ca CHX, subgroup 4) for 3.5 h at 38.5°C under 5% CO₂. For control group, IVM oocytes were fertilized using frozen‐thawed camel spermatozoa separated by swim‐up method then suspended in Fert‐TALP medium supplemented with 6 mg/ml BSA (FAF) + 10 μg/ml heparin. In all groups, oocytes were in vitro cultured in SOFaa medium + 5% FCS and 5 μg/ml insulin + 50 μg/ml gentamycin. Cleavage rate and embryo development were checked on Days 2, 5 and 8. An average of 11.3 ± 0.3 COCs were recovered/dromedary ovary. Categories 1 and 2 represented 33.1% and 34.8%, respectively, and were significantly higher (p < 0.01) than the other categories (19.1, 9.2 and 2.6% for categories 3–5, respectively). Category 6 (embryo‐like structures) represented 1.2% of the recovered oocytes, staining of these embryo‐like structures with orcien dye indicated the presence of divided cells with condensed nuclei. Dromedary oocytes averaged 166.2 ± 2.6 μm in diameter with black cytoplasm. Chemical activation of IVM dromedary oocyte with first Pb in 7% ethanol or 50 μM Ca A followed by culture in 2 mM 6‐DMAP showed significantly higher (p < 0.01) cleavage and developmental rates to the morula stage than oocytes activated using 7% ethanol or 50 μM Ca A followed by 10 μg/ml CHX or in vitro fertilized control group. Higher (p < 0.01) proportion of oocytes sequentially cultured in 10 μg/ml CHX or that in vitro fertilized were arrested at the 2–4‐cell stage compared with that cultured in 6‐DMAP.     

Dormancy and viability of Phalaris minor seed in a rice–wheat cropping system

Seed placement, soil temperature and soil moisture content influenced the process of after-ripening in Phalaris minor seeds. Seeds of P. minor collected from the soil just after wheat harvesting exhibited higher germination than seeds from P. minor threshed directly. There was a pronounced impact of periodic inhabitation of seed into the soil on germination after its dispersal. Germination was strongly inhibited when the seed was kept in soil at more than field capacity (FC) or in water. Maximum germination of seed incubated in soil at FC occurred at 30°C while a temperature of 40°C favoured after-ripening of seed when mixed with dry soil or kept dry without any medium. Release from conditional dormancy was quicker in the seed retrieved from the soil kept at 20°C than at 10°C. Seed release from conditional dormancy and germination increased with a rise in temperature from 30 to 40°C when the seed was retrieved from incubation in soil at FC for 70 days. The seed kept immersed in water was least responsive to a rise in temperature. Seed recovered from dry soil, or kept without any medium, responded quickly at both temperatures. Light enhanced the germination of Phalaris minor seed. The seedbank subjected to rice (Oryza sativa) field management conditions lost vigour in comparison with the seed stored in laboratory. There was significant variability in seed viability when exposed to differential water management conditions in rice.     

Utilization of citrus pulp based diets and Enterolobium cyclocarpum (JACQ. GRISEB) foliage by West African dwarf goats

Sixteen West African dwarf goats weighing 5.0–5.6 kg were used in an experiment that lasted 112 days to investigate the utilization of citrus pulp based diets and E. cyclocarpum. A control diet which contained 88.5% dried brewers' grains (DBG) and other three experimental diets in which DBG was replaced with dried citrus pulp (DCP) at 25, 50 and 75% levels, respectively constituted the four treatments. The goats were divided into four groups of four animals each to balance for variation in live weight before they were assigned to the four different experimental diets. Significant differences (P < 0.05) were obtained in growth rate with (22.14–34.02 g/d) the highest and lowest value from 50 and 75% DCP inclusion respectively. The digestibility coefficients of DM, Ash, NFE, NDF, ADL, cellulose and hemicellulose increased with increasing levels of dried citrus pulp in the diets and were highest at 75% level of replacement. However, the CP digestibility of 83.85% was highest in the control diet and was significantly (P < 0.05) different from other diets containing citrus pulp. Nitrogen intake (g/d) decreased significantly (P < 0.05) with increasing levels of dried citrus pulp in the diets from 45.57–33.28 and was lowest in the control diet. Nitrogen balance also followed the same trend, being highest (42.07 g/d) at 25% DCP and lowest at 75% DCP. The Packed cell volume (PCV), haemoglobin concentration (Hb), red blood cells (RBC), white blood cells (WBC) and total blood protein (TBP) were significantly (P < 0.05) different across the dietary treatments at the start and end of the trial. The values for PCV, RBC, MCH, glucose and total protein decreased slightly in the control diet. Serum glutamate pyruvate transaminase (SGPT) values also increased significantly (P < 0.05) with increasing levels of dried citrus pulp in the diets at the end of the experiment and were highest (6.50 IU/L) at 75% level of citrus pulp. Therefore, the efficient utilization of citrus pulp and E. cyclocarpum by WAD goats was attained at the 50% level of inclusion in the diets.