Traditional reserved pastures namely ‘Olopololi/Alalili’ for Maasai, ‘Ngitili’ for Sukuma and ‘Milaga’ for Gogo have been in use among the pastoral and agropastoral communities for many years. These reserves provide dry season feed for ruminant livestock especially cattle, sheep and goats. Apart from the provision of forage materials, these reserves provide fuel wood, construction material and medicinal plants. These traditional forage conservation practices also contribute to soil conservation and forage species biodiversity. However, studies conducted in these traditional forage reserves at Tingatinga (Maasai), Makang’wa (Gogo) and in Mwamishali/Mwanyanhina (Sukuma) in Tanzania show limitations of the reserves especially, in providing adequate dry matter and proteins for both maintenance and production of livestock. Nevertheless, there are opportunities for improvement on these traditional practices through introduction of improved grasses, legumes and tree/shrub species as well as proper maintenance of the superior local species and cultivars.

The objective of this study was to assess the genetic improvement programme of the Mpwapwa dairy cattle breed over the past four decades, based on on-station selection and breeding. Estimates of genetic parameters and genetic trends for total lactation milk yield (LMY), 305-day lactation milk yield (305LMY), lactation length (LL), age at first calving (AFC), and calving interval (CI) were derived. The study used 1,003 lactation records from 385 cows and 78 sires collected from 1967 to 2012. Genetic parameters were estimated using an animal model procedure with ASReml software. The heritability for LMY and 305LMY were moderately high (0.33 ± 0.11-0.44 ± 0.04) and low for LL (0.13 ± 0.17.0). Repeatability for LMY and 305LMY was high (0.62 ± 0.04-0.70 ± 0.03) and moderate for LL (0.27 ± 0.06). The heritability for AFC (0.13 ± 0.11) and CI (0.10 ± 0.05) were low. The repeatability for CI was low (0.10 ± 0.05). Genetic correlation of 305LMY with LMY and CI were 0.87 ± 0.02 and -0.06 ± 0.009, respectively, while the corresponding phenotypic correlation estimates were 0.82 ± 0.01 and -0.01 ± 0.001. Variation among animal estimated breeding values (EBV) was significant, suggesting that selection to improve these traits is feasible. Thirty seven out of 78 sires had favourable EBV (0-900 kg) for milk yield, which suggests that selection for specific sires could result in increased LMY. Annual rates of sires EBV change for 305LMY, LL, CI, and AFC were -0.05, 0.15, and -0.14 days, respectively. All these traits showed that a decline in genetic progress for Mpwapwa dairy cattle in the on-station breeding programme.

Highlights This study evaluates the effect of heat stress on milk production and describes the pattern of response of milk yield to increasing heat load, in small holder dairy farms in sub-Saharan Africa. Milk yield showed a W-shaped pattern of response across the THI scale. Cows experienced heat stress in the THI window between THI values of 67 and 76. Milk loss plateaued beyond THI value of 76 suggesting that the animals acclimatized to the heat stress conditions despite the initial heat load shock.

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.

A study to compare the effects of supplementing Delonix elata, Grewia similis, Tamarindus indica and sunflower seed cake on intake and growth rate of dual-purpose goats fed low quality Buffel grass (Cenchrus ciliaris) hay was carried out. Twenty-eight male goats aged five to seven months (mean weight 12.93±3.94 kg) were randomly allocated to four dietary groups in a completely randomised design. The diets were hay plus Grewia similis, hay plus Delonix elata, hay plus Tamarindus indica and hay plus sunflower seed cake. All diets were supplemented with maize bran. The experimental period was 90 days. Voluntary dry matter intake of the supplements was higher for Tamarindus indica (275.5 g/day) and Grewia similis (201.8 g/day) and lowest for sunflower seed cake (81 g/day). Goats supplemented with Grewia similis had the highest hay intake (183.8 g/day) while those supplemented with sunflower seed cake had the lowest hay intake (98.9 g/day). Animals fed browse supplements gained significantly more weight (p<0.001) than those with sunflower seed cake. There were no significant differences in live weight change between goats fed the different browses. However, those fed Tamarindus indica gained an average of 20.79 g/d which was slightly higher than the gains for those on Grewia similis and Delonix elata while those fed sunflower seed cake lost weight. Correspondingly, goats supplemented with browse leaf meals had higher feed conversion ratios than those supplemented with sunflower seed cake and required 23.91 to 35.06 g DM of feed to produce one g of weight gain per day. In a separate study, the DM disappearance pattern indicated that Grewia similis and Delonix elata were highly degradable compared to Tamarindus indica. At 24 h of incubation, DM degradability was 627, 588 and 345 g/kg DM for Grewia similis, Delonix elata and Tamarindus indica, respectively. In another study in vivo DM digestibility ranged from 46.1% (for hay alone) to 56.2% (for hay plus Grewia similis). It was concluded that the addition of Tamarindus indica, Grewia similis and Delonix elata leaf meals to Cenchrus ciliaris hay resulted in increased total DM intake, in vivo digestibility and growth rate. Therefore, leaf meals of indigenous browses particularly Tamarindus indica and Grewia similis could be used as supplementary feeds for small ruminants grazing on poor quality roughages during the dry season rather than use of expensive, less effective and intermittently available sunflower seed cake.