Effect of hygiene and medication on preweaning survival and growth of Djallonké sheep in Atacora, Benin

Biosecurity and water, sanitation, and hygiene (WASH) interventions in animal agricultural settings for reducing infection burden, antibiotic use, and antibiotic resistance: a One Health systematic review

Prevention and control of infections across the One Health spectrum is essential for improving antibiotic use and addressing the emergence and spread of antibiotic resistance. Evidence for how best to manage these risks in agricultural communities-45% of households globally-has not been systematically assembled. This systematic review identifies and summarises evidence from on-farm biosecurity and water, sanitation, and hygiene (WASH) interventions with the potential to directly or indirectly reduce infections and antibiotic resistance in animal agricultural settings. We searched 17 scientific databases (including Web of Science, PubMed, and regional databases) and grey literature from database inception to Dec 31, 2019 for articles that assessed biosecurity or WASH interventions measuring our outcomes of interest; namely, infection burden, microbial loads, antibiotic use, and antibiotic resistance in animals, humans, or the environment. Risk of bias was assessed with the Systematic Review Centre for Laboratory Animal Experimentation tool, Risk of Bias in Non-Randomized Studies of Interventions, and the Appraisal tool for Cross-Sectional Studies, although no studies were excluded as a result. Due to the heterogeneity of interventions found, we conducted a narrative synthesis. The protocol was pre-registered with PROSPERO (CRD42020162345). Of the 20 672 publications screened, 104 were included in this systematic review. 64 studies were conducted in high-income countries, 24 studies in upper-middle-income countries, 13 studies in lower-middle-income countries, two in low-income countries, and one included both upper-middle-income countries and lower-middle-income countries. 48 interventions focused on livestock (mainly pigs), 43 poultry (mainly chickens), one on livestock and poultry, and 12 on aquaculture farms. 68 of 104 interventions took place on intensive farms, 22 in experimental settings, and ten in smallholder or subsistence farms. Positive outcomes were reported for ten of 23 water studies, 17 of 35 hygiene studies, 15 of 24 sanitation studies, all three air-quality studies, and 11 of 17 other biosecurity-related interventions. In total, 18 of 26 studies reported reduced infection or diseases, 37 of 71 studies reported reduced microbial loads, four of five studies reported reduced antibiotic use, and seven of 20 studies reported reduced antibiotic resistance. Overall, risk of bias was high in 28 of 57 studies with positive interventions and 17 of 30 studies with negative or neutral interventions. Farm-management interventions successfully reduced antibiotic use by up to 57%. Manure-oriented interventions reduced antibiotic resistance genes or antibiotic-resistant bacteria in animal waste by up to 99%. This systematic review highlights the challenges of preventing and controlling infections and antimicrobial resistance, even in well resourced agricultural settings. Most of the evidence emerges from studies that focus on the farm itself, rather than targeting agricultural communities or the broader social, economic, and policy environment that could affect their outcomes. WASH and biosecurity interventions could complement each other when addressing antimicrobial resistance in the human, animal, and environmental interface.

The combined effects of the provision of feed and healthcare on nutrient utilization and growth performance of sheep during the early or late dry season

An on-farm study was conducted to determine the combined effects of the provision of feed and healthcare on nutrient use and growth performance of sheep during the early or late dry season. A total of 36 smallholder sheep farmers with a flock size of ≤7 was randomly selected within each of the three administrative regions in Northern Ghana. The sheep grazed on a heterogeneous natural pasture and offered crop residues as basal diet (control) or were additionally provided with a concentrate feed plus orthodox healthcare to control diseases and pests (CH) in a completely randomized block design. The provision of orthodox healthcare included scheduled control of endo- and ecto-parasites and administration of broad-spectrum antibiotics. Data was analyzed for the fixed effects of CH, season, or CH × season using the mixed model procedure of Genstats^®. The CH regimen had no effect (P = 0.098) on intake of natural pasture but pasture intake increased (P = 0.012) during the late dry season. Sheep on the CH regime had higher DM (P = 0.026) and N (P = 0.068) digestibility and improved ADG (P = 0.001) and feed conversion efficiency (P = 0.020) than those on the control. We hypothesize that improvements in growth performance of sheep on the CH regimen could be related to availability of nutrients for growth that will otherwise have been used for repair of damaged tissues caused by gastrointestinal parasites and ticks. Sheep on the CH regimen also had a higher concentration of fecal N during the late dry season when CP concentration was relatively higher than that in the early dry season (63.2 vs 60.9 g/day DM) when CP concentration of pasture was lower.

Mitogenome revealed multiple postdomestication genetic mixtures of West African sheep

Notable diversity observed within African ovine breeds makes them of great interests, but limited studies on genetic origins and domestications remain poorly understood. Here, we investigate the evolutionary status of West African native breeds, Djallonke and Sahelian sheep using mitogenome sequencing. Compared with other ovine mitogenome sequences, West African sheep were revealed a Eurasian origin, and the initially tamed sheep breeds in West Africa have been genetically mixed with each other and mixed with European breeds. Worldwide domestic sheep is deemed the Eurasian origin and migrated west to Europe and Africa and east to the Far East, in which dispersed and received selection for acclimation to autochthonic environment independently and ultimately evolved into different native breeds, respectively. Our results contribute to the comprehensive understanding of the domestic sheep origin and reveal multiple postdomestication genetic amelioration processes.