This study characterized breeding, housing, feeding and health management practices in positive deviants and typical average performing smallholder dairy farms in Tanzania. The objective was to distinguish management practices that positive deviant farms deploy differently from typical farms to ameliorate local prevalent environmental stresses. In a sample of 794 farms, positive deviants were classified on criteria of consistently outperforming typical farms (p < 0.05) in five production performance indicators: energy balance ≥ 0.35 Mcal NEL/d; disease-incidence density ≤ 12.75 per 100 animal-years at risk; daily milk yield ≥ 6.32 L/cow/day; age at first calving ≤ 1153.28 days; and calving interval ≤ 633.68 days. The study was a two-factor nested research design, with farms nested within the production environment, classified into low- and high-stress. Compared to typical farms, positive deviant farms had larger landholdings, as well as larger herds comprising more high-grade cattle housed in better quality zero-grazing stall units with larger floor spacing per animal. Positive deviants spent more on purchased fodder and water, and sourced professional veterinary services (p < 0.001) more frequently. These results show that management practices distinguishing positive deviants from typical farms were cattle upgrading, provision of larger animal floor spacing and investing more in cattle housing, fodder, watering, and professional veterinary services. These distinguishing practices can be associated with amelioration of feed scarcity, heat load stresses, and disease infections, as well as better animal welfare in positive deviant farms. Nutritional quality of the diet was not analyzed, for which research is recommended to ascertain whether the investments made by positive deviants are in quality of feeds.

In smallholder dairy-cattle farming, identifying positive deviants that attain outstanding performance can inform targeted improvements in typical, comparable farms under similar environmental stresses. Mostly, positive deviants are identified subjectively, introducing bias and limiting generalisation. The aim of the study was to objectively identify positive deviant farms using the Pareto-optimality ranking technique in a sample of smallholder dairy farms under contrasting stressful environments in Tanzania to test the hypothesis that positive deviant farms that simultaneously outperform typical farms in multiple performance indicators also outperform in yield gap, productivity and livelihood benefits. The selection criteria set five performance indicators: energy balance, disease-incidence density, daily milk yield, age at first calving and calving interval. Findings proved the hypothesis. A few farms (27: 3.4%) emerged as positive deviants, outperforming typical farms in yield gap, productivity and livelihood benefits. The estimated yield gap in typical farms was 76.88% under low-stress environments and 48.04% under high-stress environments. On average, total cash income, gross margins and total benefits in dairy farming were higher in positive deviants than in typical farms in both low- and high-stress environments. These results show that the Pareto-optimality ranking technique applied in a large population objectively identified a few positive deviant farms that attained higher productivity and livelihood benefits in both low- and high-stress environments. However, positive deviants invested more in inputs. With positive deviant farms objectively identified, it is possible to characterise management practices that they deploy differently from typical farms and learn lessons to inform the uptake of best practices and extension messages to be directed to improving dairy management.

This study investigated the effects of feed on milk yield and quality through feed monitoring and quality assessment, and the consequent enteric methane gas emissions from smallholder dairy farms in drier areas of Rwanda, using the Tier II approach for four seasons in three zones namely; Mayaga and peripheral Bugesera (MPB), Eastern Savanna and Central Bugesera (ESCB), and Eastern plateau (EP). The study was carried out using 186 dairy cows with a mean live weight of 292 Kg in three communal cowsheds. The milk quality analysis was carried out on 418 samples. Data collected were subjected to ANOVA.The dry matter intake was lower (p<0.05) in the long dry season (7.24 Kg) with the ESCB zone having the highest value of 9.10 Kg. The Dry matter digestibility varied between seasons and zones ranging from 52.5 to 56.4% for seasons and from 51.9 to 57.5% for zones. The daily protein supply was higher (p<0.05) in the long rain season with 969 g. The mean daily milk production of lactating cows was 5.6 L with a lower value (p<0.05) during the long dry season (4.76 L) and MPB zone having the lowest value of 4.65 L. The yearly milk production per cow was 1179 L. The milk fat varied from 3.79 to 5.49% with a seasonal and zone variation. No variation was observed with milk protein. The seasonal daily methane emission varied from 150 g for the long dry season to 174 g for the long rain season (p<0.05). The mean emission factor was 59.4 Kg of methane/year. The methane emission per unit of milk production was lower in EP zone (46.8 g/L). Farmers should use high-quality feeds to increase the milk yield and reduce the methane gas produced per unit of milk

In dairy farming, deploying effective animal husbandry practices minimise disease infections and animal mortality. This improves animal health and welfare status, which is important in tropical smallholder dairy farming, where animals are persistently exposed to multiple environmental stresses. The hypothesis of this study was that animals managed in positive deviants and typical farms suffer different levels of disease infections and mortality, whether under low-or high-stress environments. The study adopted a two-factor nested design with farms contrasting in the level of animal husbandry (positive deviants and typical farms) nested within environments contrasting in the level of environmental stresses (low-and high-stress). A total of 1,999 animals were observed over 42 month period in the coastal lowlands and highlands of Tanzania. The disease prevalence was lower (p < 0.05) in positive deviant farms than in typical farms under low-stress (10.13 vs. 33.61 per 100 animal-years at risk) and high-stress (9.56 vs. 57.30 per 100 animal-years at risk). Cumulative disease incidence rate was also lower (p < 0.05) in positive deviant farms than in typical farms under low-stress (2.74% vs. 8.44%) and high-stress (2.58% vs. 14.34%). The probability of death for a disease infected dairy cattle was relatively lower in positive deviant farms compared to typical farms under low-stress (0.57% vs. 8.33%) and high-stress (0.60% vs. 6.99%). Per 100 animal-years at risk, the mortality density of cattle was lower (p < 0.05) in positive deviant farms compared to typical farms, 15.10 lower in low-stress and 2.60 lower in high-stress. These results show that compared to typical farms, positive deviant farms consistently attained

No abstract