The Impact of Harvest Frequency on Herbage Yield and Quality of Cynodon nlemfuensis

Ruminants in Ghana experience feed deficit in the dry season leading to loss of weight and condition. To curb this problem of weight loss, there is the need to raise their plain of nutrition in the critical months of the year when feed is low in quantity and quality. This can be achieved by maximising forage production through appropriate harvest management practices. This study sought to find the effect of repeated harvest on dry matter (DM) yield of Cynodon nlemfuensis (Cynodon) in the coastal savanna of Ghana. It was hypothesised that infrequent repeated harvest will improve DM yield and nutritive value of Cynodon. An area of 7.0 m by 5.5 m was used for a two year study (2013 and 2014). The treatments were harvest of Cynodon at 24 (T1), 12 (T2) and 6 (T3) weeks intervals. The Randomised Complete Block Design was used with four replicates per treatment. Dry matter yield and plant cell wall constituents viz. NDF, ADF and Cellulose contents decreased significantly (P < 0.05) in the order T3<T2<T1, indicating that DM yield and plant cell wall constituents decreased with increasing harvest frequency. Crude protein content (CP) decreased significantly (P < 0.05) in the order T1<T2<T3, indicating that CP content increased with increasing harvest frequency. The study has shown that repeated harvest of Cynodon provided lower DM yield of better quality, with harvest at six weeks interval exceeding the minimum CP level required for adequate intake and digestibility by ruminant livestock

Chemical composition, in vitro dry matter digestibility and Gas production of four browse species and their combinations used as feed for small ruminants

Browse species as complete feed for ruminants is uncommon. This may be due to low dry matter (DM) and high condensed tannins (CT) contents limiting its potential to influence weight gain. Drying however improves DM content and reduces CT levels and its astringency. The objective of this study was to determine chemical composition, in vitro parameters and to evaluate the potential benefits of feeding small ruminants on dried browse leaves and their combinations. The browse species were Albizzia lebbek, Gliricidia sepium, Moringa oleifera and Millettia thoningii. Rumen fluid was obtained from two fistulated forest type wethers for the in vitro evaluation. The DM, crude protein (CP), ash, CT, neutral detergent fibre (NDF), acid detergent fibre (ADF), cellulose and lignin were 866-916 g/kg, 101-303 g/kg DM, 74.7-200 g/kg DM, 0.9-1.3 g/kg DM, 202-552 g/kg DM, 205-520 g/kg DM, 94-381 g/kg DM and 105-192 g/kg DM respectively. The organic matter digestibility (OMD), in vitro dry matter digestibility (IVDMD), in vitro gas production (IVGP), metabolisable energy (ME) and short chain fatty acids (SCFA) of the four browse species and their combinations recorded were 314.9-721.6 g/kg DM, 515.4-721 ml/g DM, 139-602 ml/g DM, 314.6-1406.9 ml/g DM and 3.1-14.4 ml/g DM respectively. There were positive associative effects shown by the combined browse leaves between IVDMD and IVGP. The regression analyses revealed that relationships between IVGP and CP and IVDMD and CT and all relationships between OMD, SCFA, ME and IVGP were significant (p<0.05). All the browse species and their combinations had IVDMD values of more than 500 g/kg DM and low gas production. The high CP and ash contents, low CTs, low to moderate fibre components, moderate to high IVDMD and low IVGP of the four browse species and their combinations make them potentially valuable as feed resources for small ruminant production

Grazing capacity estimates : why include biomass estimates from arable lands?

Forage for ruminants in the dry season were assessed and matched with feed requirements in three villages in Zimbabwe, namely; Chiweshe, Makande and Mudzimu. Stocking rates were compared with grazing capacity to determine grazing intensities. Grazing capacities were estimated with and without crop residues to assess the importance of crop residues in livestock feeding during the dry season. 333, 742 and 5,320 tonnes of forage DM were estimated from crop yields on arable lands in Chiweshe, Makande and Mudzimu, representing 31.8, 19.2 and 83.1% respectively of total available forage DM produced in the villages. When including crop residues in the estimation of grazing capacity, all three villages were understocked. However, without the contribution of crop residues, the grazing intensities changed. Grazing capacities for Chiweshe, Makande and Mudzimu declined from 2.8 to 4.9, 1.5 to 2.8, and 1.1 to 8.2 ha/LU representing a reduction of 44, 46 and 87% respectively, making all three villages overstocked. Results obtained revealed that in areas with intensive crop production, crop residues assume great importance in decreasing the level of feed deficit in the dry season. When the contribution of crop residues is taken into account in grazing capacity estimates, the level of grazing intensity is not as high as is normally depicted.Le fourrage pour les ruminants pendant la saison sèche a été évalué en tenant compte des exigences alimentaires dans trois villages au Zimbabwe, à savoir : Chiweshe, Makande et Mudzimu. Les taux de charge étaient comparés avec la capacité de pâturage pour déterminer l'intensité de pâturage. La capacité de pâturage était évaluée avec et sans les résidus de récolte, afin de déterminer l'importance des résidus de récolte pour l'alimentation du bétail durant la saison sèche. 333 ; 742 et 5 320 tonnes de matière sèche (MS) du fourrage ont été évalués à partir du rendement des cultures sur les terres arables de Chiweshe, Makande et Mudzimu, soit 31,8 ; 19,2 et 83,1% de MS totale du fourrage produite dans les villages. Lorsqu'on a inclus les résidus de récolte dans l'évaluation de la capacité de pâturage, on a observé un sous-pâturage dans tous les trois villages. Cependant, sans les résidus de récolte, l'intensité de pâturage a changé. Les capacités de pâturage pour Chiweshe, Makande et Mudzimu ont diminué de 2,8 à 4,9 ; 1,5 à 2,8 et 1,1 à 8,2 ha/UB, soit une réduction de 44; 46 et 87% respectivement, ce qui a entrainé une surcharge pastorale dans tous les trois villages. Les résultats obtenus ont montré que dans les zones à production agricole intensive, les résidus de récolte ont une grande importance puisqu'ils réduisent le niveau de déficit alimentaire pendant la saison sèche. Lorsqu'on tient compte des résidus de récolte dans l'évaluation de la capacité de pâturage, le niveau de l'intensité de pâturage n'est pas aussi élevé que ce qu'il est normalement.Bulletin of Animal Health and Production in Africa Vol. 54 (4) 2006: pp. 33-4

Substrates most preferred for black soldier fly Hermetia illucens (L.) oviposition are not the most suitable for their larval development

Larvae of black soldier fly (BSF), Hermetia illucens (L.1758) (Diptera: Stratiomyidae), are increasingly being used as animal feed ingredients. Larvae are usually produced by placing eggs, obtained from adult rearing on growing substrates but can also be obtained by exposing substrates to naturally occurring BSF females. In the latter system, the substrate needs not only to be nutritious for the larvae but also attractive to the females for oviposition. The ‘preference-performance principle’ suggests that female insects prefer to oviposit in substrates that maximise offspring fitness. In this study conducted in Ghana, six organic substrates known to be suitable for BSF production were evaluated for their suitability as oviposition attractants and larval development: pito mash (waste from a locally brewed sorghum drink), millet porridge mash, pig manure, chicken manure, fruit waste, and waste from roots and tubers. These were first exposed outdoors to measure the quantity of eggs laid on them by naturally occurring BSF females. In a second experiment, the quality of the substrates as larval rearing media was tested by placing a standard amount of young larvae to measure the individual and total weights of prepupae obtained, their number, and their development time. The nutritional profiles of both the prepupae and the substrates were determined. The substrate used significantly influenced the quantity of eggs laid and the development of the resulting prepupae, but the substrates most favourable for larval development were not the most favoured by gravid BSF for oviposition. In the oviposition tests, millet porridge mash was the most attractive substrate, whereas only a few eggs were recovered from the other substrates. All substrates allowed the successful development of larvae but pig manure was more productive than the others