Waste dates (most dominantly treated as waste) representing ~20–30% of total dates production have been used as a replacement of dietary starch in tilapia feed. This has led to the improvement of growth rate, feed conversion, specific growth rate and protein efficiency ratio. In another study, the addition of date palm seed—most dominantly treated as waste—to the diet of the African catfish has led to a considerable increase of the weight gain, specific growth rate, protein efficiency ratio and protein productive value, as well as the improvement of final fish carcass and hematological indices. The improved growth rate and nutrient utilization could be explained by the presence of a range of digestive enzymes in the date palm seeds. A research has been conducted in Kuwait to evaluate the technical feasibility of use of the locally and sustainably available date palm leaflets as a roughage to substitute the imported barley straw in feeding of Friesian and Holstein cows. The results of feeding experiments revealed that milk yields, milk composition and live weight gains of cows fed by either date palm leaflets or barley straw did not significantly differ. Therefore, it can be concluded that the date palm leaflets—a local sustainable resource treated as waste—can be used as an acceptable alternative roughage in feeding of cows to the expensive imported barley straw. Another research was devoted to the evaluation of ensilage, made from cardboxes, annually available with about 100,000 tons in Kuwait and date palm leaves resulting from annual pruning of date palm and treated as waste. The bioconversion and upgrading of nutritive value of cardboxes and date palm leaves to silages were investigated over 90 days through chemical and microbial treatments. The qualitative aspects of the produced silages for ruminants were evaluated. It can be concluded from the research results that cardboxes and date palm leaves can be effectively ensilaged, and the resultant silages are acceptable and palatable to be used as ruminant feed in arid regions. A research has been conducted to evaluate the potentiality of use of date palm leaves for feeding of Omani sheep. Oman and the whole gulf region suffer as an arid region from the shortage of animal feed representing an obstacle in livestock investment projects. This study has been conducted on 32 one-year old male Omani native sheep of starting body weight ~32 kg in a feeding trial for 120 days. The conducted feeding included two types of roughages: Rhodes grass hay (RGH) and urea-treated date palm leaves (UTPF). The experimental animals fed by the date palm leaves were in good health throughout the trial. But the sheep fed by UTPF had lower feed intake as compared with those fed by RGH, but feed intake/body weight was similar across diet groups. Therefore, date palm leaves can be used as a component of feed for Omani sheep in case of nutritional shortage frequently experienced in arid zones. A research has been conducted in Algeria to evaluate, in vitro, the ruminal fermentation and nutritive value of the date palm leaves, pedicels, date pits and waste dates. To conduct this study, 20–30 specimens of leaves, pedicels and date pits were taken from Deglet-Nour palm and waste dates from three varieties Bourus, Harchaya and Kentichi in Biskra in Saharan Atlas region in Algeria. Vetch-oat hay was taken as a control reference. All the samples including the control were oven-dried at 50 °C and ground to pass 1 mm screen. The results of this research showed that the date palm leaves have the highest NDF, ADF, lignin and crude protein contents (609, 435, 84, 649 kg−1 DM), respectively. The cumulative gas production at 144 h of incubation was greatest for Kentichi dates (330 mLg−1 DM) and lowest for date pits (69 mL−1 DM). Regardless of the variety, waste dates showed the highest DM effective ruminal degradability and organic matter digestibility. The date pits seemed to be a poorly degradable material. These results indicate that waste dates—though of low-protein content—are highly digestible with energy concentration as high as that of vetch-oat hay. The palm leaves and pedicels can be considered as highly fibrous emergency roughages for low-producing animals. Protein supplements should be added when date palm byproducts are used as feedstuff in order to balance the ruminant diets. An important study has been conducted with the objective of learning about farmer’s knowledge south of Tunisia on the use of date palm byproducts (DPBP) as forage resources. To conduct this study, samples of wasted dates, date pits, leaves, peduncles and pedicels of two dominant varieties (Deglet Nour and Kentah) were taken and analyzed for dry matter, crude protein, total ash, crude fiber, natural detergent fiber, acid detergent fiber and acid detergent lignin. The in vitro digestibility measurements have been taken on each sample using rumen juices from three species: sheep, goat and dromedary. An extensive socio-economic survey has been conducted in a sub-region of Nefazoua (EL Faoura) concerning the use of DPBP in livestock feeding. It can be concluded from the results of this study that DPBP, taken individually, are highly unbalanced for animal nutrition: high energy content in the cases of wasted dates and date pits and high fiber content for leaves, peduncles and pedicels and for all: low crude protein content (3–6.5% of dry matter). The in vitro dry matter digestibility for wasted dates were found 74.5, 79.7 and 79.2% for sheep, goats and dromedary, respectively. The corresponding figures for leaves, peduncles and pedicels were found much lower: 12.3, 19.6 and 18.3%, respectively. Thus, the main questions to be asked in use of DPBP in ruminant feeding are how to make a well-balanced DPBP-based forage? And how to conserve this feed to overcome the problem of seasonal unavailability? This indicates the significance of research on DPBP-based silage to improve the technical and economic feasibility of use of DPBP as a local and sustainable forage resource. An important study has been conducted to evaluate the effectiveness of a combined treatment of date palm leaves by sodium hydroxide and lime for conversion into a promising ruminant feed. Date palm leaves (DPL), annually available in Iran with big quantities (e.g., 300,000–400,000 t) are being treated as waste! One of the approaches to solve this problem is to use DPL in feeding of ruminants. But DPL in its natural form has a very low ruminal digestibility (16% in vitro dry matter digestibility). The alkaline pretreatment of DPL to improve the ruminal degradability at high temperature is fast and effective, but it is a capital-intensive process. Therefore, the idea of this research was to replace only a part of costly sodium hydroxide with less expensive lime to realize a cost-effective and efficient pretreatment of DPL at a mild temperature with low concentration of sodium hydroxide. To conduct this study, DPLs were collected in Jam country in Busher province in Iran. Raw milled DPLs were pre-washed, and 10 g of dry matter basis was mixed with a solution of sodium hydroxide and lime at a 1:8 solid-to-liquid ratio in a 250 ml bottle, purged with N2 stream (60 s) to remove probable CO2 in headspace which may react with lime, tightly closed and stirred at 500 rpm for 10 min. The statistical analysis of results revealed that the impact of sodium hydroxide, lime and residence reaction time is significant (p < 0.0001). Under the optimum pretreatment conditions (sodium hydroxide loading 0.06 g NaOH/g dry biomass, lime loading of 0.09 lime/g dry biomass and residence time 71.4 h), the amount of cumulative gas production after 24 h was 101.4 ml gas/g organic matter, versus 104.6 ml gas/g organic matter for the predicted value. Thus, the results of this study proves the applicability of this low-cost efficient on-farm pretreatment to overcome the recalcitrance of date palm leaves and holds a promise to use date palm leaves—this dominantly wasted resource—for feeding of ruminants particularly in arid and semi-arid regions.