Isolation and characterization of biosurfactant-producing microbes isolated from the gastrointestinal system of broiler birds fed a commercial diet.

Antimicrobial drug resistance (AMR) from improper use of antibiotics in various livestock products is a growing hazard for humans worldwide, with current death rate in excess of 700,000 per annum linked to the problem. Microorganisms are a rich source of structurally distinct bioactive compounds designed to protect the microbes and can offset AMR challenge. A study was conducted at Chinhoyi University of Technology to isolate, identify and characterize biosurfactant secreting microbes from broiler bird's gastrointestinal tract. Analysis of variance was performed in Genstat software. 16S rRNA technique was used to identify the DNA of isolates, annotated by similarity using BLASTn analysis against the NCBI nucleotide database. Phylogenetic analysis was performed on the BLASTn outcome to have an appreciation of the evolutionary genetic relationships. Small intestine-derived samples had a wider hemolytic activity of 5.6 mm, with a 39% emulsification index. At 98.29% sequence similarity, the bacterium producing biosurfactants was identified as an Escherichia coli strain similar to the 7.1994/NIST 0056 strain. The biosurfactant substance is a derivative of decane with beta lactams, tetracyclines and sulfa drugs properties which were responsible for the observed antibacterial activity. We recommend endogenous biosurfactant production optimization experiments and in-vivo trials to evaluate the potential impacts of a biosurfactant based feed additive in broilers.

Constraints and opportunities of sweet sorghum (Sorghum bicolor L.) silage production and utilisation by smallholder milk production sector in Zimbabwe.

The objective of the scoping research was to evaluate the current situation, constraints and opportunities of sweet sorghum (Sorghum bicolor L.) silage production and utilisation by the smallholder dairy farmers in Zimbabwe. Cross sectional surveys were conducted from 61 households of six milk producers' associations (MPAs) in Chipinge, Gokwe, Mutasa, Seke, and Umzingwane districts, which were in different agro-ecological regions of Zimbabwe. Purposive and stratified random sampling was done to select households to administer structured questionnaires so as to collect data on socio-economic characteristics and dairy production. Key informant' interviews, case studies, and focus group discussions were the other data collection tools used. Total MPA dairy herd size mean differed (P < 0.05) in all MPAs averaging 16, ranging from 1 to 41 herd. Mafumise MPA had the least (P < 0.05) dairy herd size (7), whilst Gokwe, Tsonzo, Marirangwe, Claremont, and Umzingwane MPAs, had similar herd sizes (P > 0.05). There were positive (P < 0.001) relations between MPAs by seasonal milk yields, lactation days, calving intervals, dry days for different dairy breeds. Milk yields across MPAs and breeds were seasonally sensitive, being high in the wet season than dry season. All farmers (100%) had access to formal milk markets such as Milk Collection Centres, large dairy processors, and parallel markets. Farmers indicated non preference of sweet sorghum silage by their cattle as well as recurring drought affected their maize silage production. Farmers lacked knowledge on how to improve utilisation of sweet sorghum silage by using yeast, and bacteria and this justifies the need to use these probiotics in mitigating utilisation challenges for sustainable milk production.

Potential of ethno-veterinary medicine in animal health care practices in the South Pacific Island countries: a review.

The South Pacific island countries (SPIC) are among the most vulnerable countries in the world to economic shocks, climate change and natural disasters. Agriculture including livestock production makes important contribution to socio-economic development in the region. However, the livestock sector is marred by many livestock diseases, which are crippling the economies as well as threatening the food security of the island nations, most of which have high dependence on imports. Limited veterinary medical facilities, high cost of conventional medicine and remoteness of some rural farming communities make it difficult for farmers to treat their diseased animals. Nevertheless, the island nations are endowed with vast reserves of medicinal plants in diverse ecosystems including mangroves, rainforests and tropical dry forests. Despite the ubiquity of traditional medicine systems, most of the plant species have been used to treat human aliments in the SPIC and very few farmers utilise herbal medicine to treat their animals. This review highlights the common diseases affecting livestock production in the SPIC, threats to ethno-veterinary knowledge, and potential plant species and their efficacies to treat animal diseases and parasites. It also discusses the common methods of preparation of veterinary herbal medicine and possible ways of making the medicine available in the formal and informal markets in the region. It is envisaged that the review will stimulate further ethno-veterinary research among livestock disease management practices in the SPIC.

Growth performance, economic benefits and sensory characteristics of meat from broilers finished on Acacia anguistissima leaf meal-based diets.

The objective of the study was to determine growth performance, viscera organ development, economic benefit and sensory characteristics of meat from broilers finished on Acacia anguistissima leaf meal-based diets. One hundred and eighty Cobb 500-day-old chicks were used in the study. Acacia anguistissima was used as a protein source and included in broiler diets at 0, 50 and 100 g/kg. Total feed intake (TFI), average daily gain (ADG), and gain to feed ratio (G:F) and cost benefit analysis were determined. There were no differences in TFI of broilers across treatments diets. Average daily gain and gain to feed (G:F) ratio were low (P < 0.05) for broilers feeding on diet with100 g/kg acacia meal. Highest returns from weight gain were obtained from broiler chickens fed on diet with 50 g/kg inclusion level of A. anguistissima (P < 0.05). Intestinal length increased with inclusion level of A. anguistissima whereas liver and spleen weight decreased with inclusion level of A. anguistissima (P < 0.05). Female consumers gave higher scores for overall flavour intensity than male consumers (P < 0.05). Treatment diets influenced consumer sensory characteristics of broiler meat (P < 0.05). High sensory scores were observed for overall flavour intensity (OFI) for both boiled and deep fried meat from broilers fed 100 g/kg A. anguistissima. It can be concluded that A. anguistissima meal can be used effectively up to 50 g/kg in broiler diets without compromising performance of chickens and can influence a few sensory characteristics.

Growth performance of broilers fed on sprouted-roasted guar bean (Cyamopsis tetragonoloba) based diets.

In a completely randomized block design with 96 Cobb-500 broilers, a study was conducted to evaluate the potential of dietary inclusion of sprouted then roasted guar bean in broiler diets. The 96 male day-old broiler chicks, blocked by pen into equal weight groups of six chicks replicated four times per treatment, were randomly allocated to treatment diets containing graded levels of sprouted then roasted guar bean meal (GBM) at 0, 50, 100 and 150 g kg-1 inclusion level. The guar bean was sprouted and roasted to reduce guar gum effect. Total feed intake decreased significantly as the guar bean meal content increased in the starter phase (P < 0.05), but no significant differences in intake of the finisher phase (P > 0.05) were observed. Diets containing 0 and 50 g kg-1 GBM recorded significantly higher total feed intake compared to the diet containing 150 g kg-1 GBM. Although average weight gain was not significantly different in birds fed 0 and 50 g kg-1 GBM diets, it was significantly higher than in birds fed on 100 and 150 g kg-1 GBM diets. Feed conversion ratio was not significantly different among treatment groups (P > 0.05) but showed a general decreasing trend with increasing guar bean meal inclusion level, the effect being more pronounced during the starter phase. In conclusion, the optimum inclusion level of sprouted then roasted guar bean meal in broiler diets is 50 g kg-1.

Nutritionally related blood metabolites and performance of finishing pigs fed on graded levels of dietary fibre.

The objective of the study was to determine effect of feeding fibrous diets on performance and biochemical profiles of finishing pigs. A total of 84 clinically healthy male pigs were used in the experiment. Body weight of the pigs at the beginning of the experiment was 85 ± 10.1 kg. Maize cob (MC), sunflower hulls (SH), lucerne hay (LH) and dried citrus pulp (PU) were incorporated in a basal diet for finishing pigs at different inclusion levels of 0, 80, 160, 240, 320 and 400 g/kg. Effects of week of feeding, fibre source and inclusion level of fibre were significant (P < 0.05). Pigs consumed more LH compared to MC, SH and PU. Average daily gain was high for pigs consuming diets with inclusion levels of 0, 80, 160 and 240 g/kg and low for pigs consuming 320 and 400 g/kg inclusion level of fibre in a diet. There was an increase in serum total concentration (TP) with an increase in PU, MC and LH in pig diets (P < 0.05). Creatine kinase (CK) concentrations decreased as levels of PU, LH and MC increased (P < 0.05). Increasing inclusion level of LH and SH in pig diets resulted in an increase in glycated haemoglobin concentration (P < 0.05). It can be concluded that level of PU, LH, MC and SH in diets of finishing pigs negatively influences average daily feed intake, average daily gain and biochemical profiles.

Performance of Mashona doelings supplemented with different levels of velvet bean (Mucuna pruriens L. DC. var. utilis) seed meal.

The objective of the current study was to evaluate the effects of feeding increasing levels of velvet bean seed meal (VBM; 0, 12, 24, and 36 %) on the performance of Mashona doelings. Dry matter intake was lower (P < 0.05) for the control diet compared to VBM diets, but linearly declined (P < 0.05) with increasing levels of VBM. Average daily weight gain was significantly different between experimental groups. Doelings' final live weights and average daily gains were slightly higher in control group than other three supplemented groups where they linearly declined (P < 0.05) with increasing levels of VBM. The cost per kilogram of feed, however, decreased with high inclusion level of VBM. Result suggested that high inclusion level of VBM negatively influenced the growth of young goats probably due to the presence of some anti-nutritional factors which needs further investigation.

Efficacy of Strychnos spinosa (Lam.) and Solanum incanum L. aqueous fruit extracts against cattle ticks.

The efficacy of Solanum incanum and Strychnos spinosa aqueous fruit extracts was evaluated against cattle ticks in on-station experiments and laboratory tick bioassays. In the on-station experiment using cattle, fruit extracts were applied at three concentrations 5, 10, and 20 % (w/v) and compared with a commercial acaricide, Tickbuster (amitraz) spray (positive control) and no treatment (negative control). The treatments were applied at weekly intervals for 6 weeks as surface sprays on 32 Mashona cattle in a completely randomized design experiment. Ticks on individual cattle were identified, counted, and recorded daily. Peripheral blood samples were collected for parasite screening. In the laboratory, tick bioassays were conducted at four concentrations, 5, 10, 20, and 40% (w/v) fruit extracts compared to Tickbuster (amitraz) spray (positive control) and distilled water (negative control). The extracts were incubated with Rhipicephalus (Boophilus) decoloratus tick larvae and mortalities for each treatment level recorded after 24 and 48 h. The 5% Solanum incanum treatment had higher efficacy ratio (P < 0.05) than the other fruit extract concentrations of the same plant species. Efficacy ratio was higher (P < 0.05) in the 5% S. spinosa-treated cattle than in the untreated control but lower (P < 0.05) than that for the amitraz treatment. The bioassays indicated that there was a high efficacy ratio for the lowest fruit extract concentrations when ticks were exposed to acaricidal treatments for 48 h compared to 24 h. Overall, the results indicate that Solanum incanum and Strychnos spinosa individually have some acaricidal effect.

Potential for using indigenous pigs in subsistence-oriented and market-oriented small-scale farming systems of Southern Africa.

Indigenous pigs in South Africa are a source of food and economic autonomy for people in rural small-scale farming systems. The objective of the study was to assess the potential of indigenous pigs for improving communal farmer's livelihoods and to inform policy-makers about the conservation of indigenous pigs. Data were collected from 186 small-scale subsistence-oriented households and 102 small-scale market-oriented households using interviews and direct observations. Ninety-three percent of subsistence-oriented and 82 % of market-oriented households kept indigenous pigs such as Windsnyer, Kolbroek and non-descript crosses with exotic pigs mainly for selling, consumption and investment. Farmers in both production systems named diseases and parasites, followed by feed shortages, inbreeding and abortions as major constraints for pig production. Diseases and parasites were more likely to be a constraint to pig production in subsistence-oriented systems, for households where the head was not staying at home and for older farmers. Market-oriented farmers ranked productive traits such as fast growth rate, good meat quality and decent litter size as most important selection criteria for pig breeding stock, while subsistence-oriented farmers ranked good meat quality first, followed by decent growth rate and by low feed costs. We conclude that there is high potential for using indigenous pigs in subsistence-oriented production systems and for crossbreeding of indigenous pigs with imported breeds in market-oriented systems.

Market potential for guinea fowl (Numidia meleagris) products.

The survey evaluated the market potential for guinea fowl (GF; Numidia meleagris) products in the city of Harare, Zimbabwe. Questionnaires were administered to traders/producers (n = 17), retailers (n = 12), cafeteria industry (n = 33) and consumers (n = 1,680) to establish their perceptions on guinea fowl products. The average household size was 6 ± 2. Each trader sold 10 ± 6.30 keets (mean ± standard error), 33 ± 15.05 growers, 20 ± 12.69 breeders and 20 ± 10.1 crates of 30 eggs per month. Each household consumed 2.5 ± 1.39 kg of GF meat and 3 ± 0.65 dozens of GF eggs per month. Retailers purchased 52 ± 44.42 crates of GF eggs and 41 ± 30.50/kg of GF meat whilst cafeteria purchased 33.6 ± 14 crates of GF eggs and 65.5 ± 33.52 kg of GF meat per month. Growers for breeding were the major product for sale by traders (94.1%) at a price of US$7.50 ± 1.74/bird. Different industries were offering different prices for guinea fowl products because of their scarcity on the market. The mean purchase price per crate of 30 guinea fowl eggs sold to the retail and cafeteria were US$3.00 ± 0.58 and US$4.50 ± 0.50, respectively. The mean purchase prices for GF meat was lower (P < 0.05) for retailers (US$2.5 ± 0.81/kg) than cafeteria (US$3.67 ± 0.83/kg). The challenges faced by producers in the marketing of guinea fowl products included poor supply due to the absence of good road networks to connect source areas and the market, perishability of dressed chickens due to power cuts and poor publicity. Overall, the study showed that there is greater market potential for guinea fowl products and farmers can channel their products through traders, cafeteria and retail industries.

Acaricidal efficacy against cattle ticks and acute oral toxicity of Lippia javanica (Burm F.) Spreng.

In search for low-cost, safe and environmentally benign plant-based alternatives to commercial pesticides, the efficacy of Lippia javanica aqueous leaf extracts in controlling ticks on cattle, acute oral toxicity in mice and phytochemistry were evaluated. L. javanica aqueous leaf extracts at 10% and 20% w/v were effective at controlling cattle ticks but not as good as an amitraz-based acaricide Tickbuster. However, they can provide an effective tick control option where synthetic products are unavailable or unaffordable, particularly in remote parts of southern Africa. Peripheral blood samples collected showed no haemoparasites in treated cattle implying that animals did not suffer from clinical tick-borne diseases. The leaf aqueous extracts of L. javanica were tested for toxicity in BALB/c mice. While anecdotal evidence suggests L. javanica has low mammalian toxicity, within 48 h all mice fed with the L. javanica leaf aqueous extract at 12.5-37.5% v/v were lethargic, and overall mortality was 37.5% (n = 24). Thus, despite their apparent safety, water extracts of L. javanica leaves may have deleterious health implications on humans and animals if consumed at very high doses. Many compounds have been identified from L. javanica including an array of phenolic glycosides, flavonoids and essential oils but none of these are known to have acute toxic properties.

Milk yield and quality in Guernsey cows fed cottonseed cake-based diets partially substituted with baobab (Adansonia digitata L.) seed cake.

The objective of this study was to determine the effects of partially substituting cottonseed cake with graded levels of baobab (Adansonia digitata L.) seed cake (BSC) on milk yield and quality in Guernsey cows. Sixteen cows in mid-lactation and in their third parity were allocated to diets containing 0% (control), 5%, 10%, and 15% BSC in a completely randomized design. Each cow was given a daily feed ration of 6 kg and a basal diet of soya bean stover ad libitum. There were no differences in daily feed intake (P > 0.05), but basal intake differed among all treatment groups with cows on the control diet having the highest intake (30 ± 0.34 kg/day). Mean daily milk yield differed (P < 0.05) among all treatment groups. However, the control had higher milk yield of 12.1 ± 0.73 kg/day, and the 15% BSC had the least yield of 7.46 ± 0.73 kg/day. Cows on the control diet had higher milk butterfat content (6.12%; P < 0.05) than those on the BSC-based diets. Protein content differed (P < 0.05) across all treatment groups with cows on 15% BSC producing the highest protein content (3.43%) while the control had the least (2.6%). The concentration of milk total solids for cows fed on 15% BSC was higher (P < 0.05) than that from cows on other diets. Lactose content was not affected by the diets (P > 0.05). These results indicate that BSC can substitute soya bean cake in dairy diets, but milk production and butterfat content are compromised.