to determine effects of different harvesting heights (10, 30 and 50 cm above the ground) and cutting intervals (45, 60, 90 and 285 days) on yield of foliage and tubers, and chemical composition of the foliage. Cassava of the variety KM 94 grown in plots of 5 m×10 m at a planting distance of 30 cm×50 cm was hand-harvested according to respective treatments, starting 105 days after planting. Foliage from the control treatment (285 days) and all tubers were only harvested at the final harvest 285 days after planting. Dry matter and crude protein foliage yields increased in all treatments compared to the control. Mean foliage dry matter (DM) and crude protein (CP) yields were 4.57, 3.53, 2.49, and 0.64 tonnes DM ha -1 and 939, 684, 495 and 123 kg CP ha -1 with 45, 60, 90 and 285 day cutting intervals, respectively. At harvesting heights of 10, 30 and 50 cm the DM yields were 4.27, 3.67 and 2.65 tonnes ha -1 and the CP yields were 810, 745 and 564 kg ha -1 , respectively. The leaf DM proportion was high, ranging from 47 to 65%. The proportion of leaf and petiole increased and the stem decreased with increasing harvesting heights and decreasing cutting intervals. Crude protein content in cassava foliage ranged from 17.7 to 22.6% and was affected by harvesting height and cutting interval. The ADF and NDF contents of foliage varied between 22.6 and 30.2%, and 34.2 and 41.2% of DM, respectively. The fresh tuber yield in the control treatment was 34.5 tonnes ha -1 . Cutting interval and harvesting height had significant negative effects on tuber yield. The most extreme effect was for the frequent foliage harvesting at 10 cm harvesting height, which reduced the tuber yield by 72%, while the 90 day cutting intervals and 50 cm harvesting height only reduced the yield by 7%. The mean fresh tuber yield decreased by 56, 45 and 27% in total when the foliage was harvested at 45, 60 and 90 day cutting intervals, respectively. It is concluded that the clear effects on quantity and quality of foliage and the effect on tuber yield allow alternative foliage harvesting principles depending on the need of fodder for animals, value of tubers and harvesting cost. An initial foliage harvest 105 days after planting and later harvests with 90 days intervals at 50 cm harvesting height increased the foliage DM and CP yield threefold, but showed only marginal negative effect on tuber yield.

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In smallholder dairy farms (SDFs), farmers often build cowsheds using local materials and based on self-accumulated experience without due consideration to reducing the risk of heat stress. This study aimed to characterise the heat stress abatement strategies and microclimate within SDF cowsheds from four typical dairy regions of Vietnam (south lowland, south highland, north lowland and north highland) and identify the housing parameters most associated with the microclimate. The study was conducted on 32 SDFs (eight SDFs per region) in autumn 2017. Twelve housing management variables, illustrating cowshed design and heat stress abatement methods of each SDF, were collected. Six microclimate parameters, collected within the cowshed, were temperature (AT), humidity, air speed (AS), heat load index (HLI), Temperature-humidity index (THI) and accumulated heat load units (AHLU) during a day (06:00 h to 18:00 h). Factor analysis and cluster analysis was applied to group cowsheds of SDFs into clusters where SDFs in the cluster had the same cowshed characteristics. Multivariable linear models were applied to define the parameters most likely to inform future research into heat stress mitigation on SDF. Averaged from 08:00 h to 18:00 h, microclimate inside the cowsheds was considered hot (HLI > 79) in the highland and very hot (HLI > 86) in the lowland regions. Cows in the lowland regions accumulated high heat load (AHLU > 50) by 18:00 h. Cowsheds of SDFs varied widely and grouped into seven cowshed types, but no type was more effective than others in reducing heat stress conditions within cowsheds. Using roof soakers together with fans decreased AT and HLI by 1.3 °C and 3.2 units, respectively, at 14:00 h compared to 11:00 h. Each 100 m increase in altitude was associated with decreases of 0.4 °C in AT, 1.3 units in HLI and 0.8 units in THI (p < 0.001). Each meter increase in the eave height of the cowshed roof was associated with decreases of 0.87 °C in AT, 3.31 units in HLI and 1.42 units in THI, and an increase of 0.14 m/s in AS (p < 0.05). The cowshed parameters that should be prioritised for future research into the amelioration of heat stress in SDF cows include using the roof soakers together with fans, increasing altitude, eave roof height and floor area per cow.

Rice straw is a readily available, practical, and cheap source of fodder for feeding ruminants such as buffaloes, cattle, goats, and sheep. Livestock producers commonly haul and stack rice straw from their rice farm, which then forms reserved feed for their animals during lean months or when good-quality roughages are scarce. The feeding of pure rice straw to ruminants during the stages of fast growth and early lactation has been shown to affect both body condition score and animal performance. This is due to lower dry matter intake and protein content (from 4.0% to 4.7% crude protein) of the straw. The high silica and lignin contents of straw also contribute to poor nutrient (dry matter and protein) digestibility (<50%). So, pretreatment of straw is necessary to enhance its contribution to improving meat and milk production. Science-and technology-based farm strategies to optimize the nutritive and feeding values of rice straw had been developed with significant improvement on intake, nutrient digestibility, and animal performance. These technologies were also proven effective in contributing additional income to livestock producers from the sales of milk or live animals. This chapter presents and discusses current innovations and developed technologies on how the nutritive (nutrient composition and fiber fraction) and feeding values of rice straw can be improved.

In a 4 x 4 Latin square design study, four rumen-cannulated local yellow cattle, average weight 330 kg, were fed urea-treated fresh rice straw (UFRS) ad libitum and given 1 kg cassava root meal daily as basal diet in each 30-day trial period. Four treatment levels of crude protein of fresh cassava tops (FCT) were supplied: 0 (FCT0), 50 (FCT50), 100 (FCT100) and 150 g (FCT150) crude protein per 100 kg body weight. The results showed a continuous decrease in dry matter intake (DMI) of UFRS with increasing level of FCT supplementation (p<0.001). Total DMI for treatments FCT150, FCT100, FCT50 and FCT0 were 2.66, 2.42, 2.23 and 2.05 kg dry matter per 100 kg live weight per day, respectively. Increasing levels of FCT supplementation increased the concentration of total volatile fatty acids (p<0.05) and ammonia (p<0.001) and resulted in a decrease in pH (p<0.05). Rumen protozoa population varied widely but was significantly lower with increasing FCT supplementation (p<0.001), while rumen bacteria population was higher (p<0.05). Overall, average plasma triiodothyronine and thyroxine concentrations in the four groups were respectively 1.36, 0.94, 0.91, 0.80 ng/ml (p<0.01) and 60.9, 48.7, 45.2, 42.5 ng/ml (p<0.001). There were non-significant differences in alanine aminotransferase and aspartate aminotransferase concentrations among the treatments.