Chemical composition of alfalfa silage with waste date and its feeding effect on ruminal fermentation characteristics and microbial protein synthesis in sheep
Feeding by‐products to livestock is a practice as old as the domestication of animals. The main advantages have been less dependency of livestock on grains that can be consumed by humans and the reduction of costs related to waste management. Date or date palm (Phoenix dactylifera L.) is recognised as a rich source of carbohydrates (total sugars, 44–88%, mainly glucose and fructose) fat (0.2–0.5%), crude protein (2.3–5.6%), dietary fibre (6.4–11.5%), minerals (the percentage of each mineral in dried dates varies from 0.1 to 916 mg/100 g date) and vitamins (such as vitamin C, B1, B2, A, riboflavin and niacin; Al‐Hooti et al., 1997). Date pits, also called pips, stones, kernels or seeds form part of the integral date fruit in the order of, depending on variety and quality grade, 6–12% of its total weight in the Tamr stage contains approximately 7–10% fat. Protein in date fruit is in the range of 1–3% but in date stone it is approximately 5–7% (Barreveld, 1993). The major date producers in the world are situated in the Middle East and North Africa. Iran is the second largest date producing country in the world. In 2013, it produced 1.08 million tonnes that makes 14% of world's dates production (FAO 2016). Waste date pulp, low‐grade rejected date fruits and the date seeds (pits, stones) are the three major by‐products coming out of the date fruit processing plants (Sidhu, 2012). Approximately 20–30% of total harvested dates are wasted date which is non‐edible for human consumption and could be beneficially used as an ingredient in the diets of small ruminants because of inadequate texture (too soft or too hard), or simply due to their low quality (MAJ 2016). Waste date can be used as a carbohydrate source during alfalfa ensiling. It is not clear whether using waste date as an additive to alfalfa before ensiling can improve the silage quality, therefore, the objectives of this study were to evaluate the effects of adding different levels of waste date into alfalfa forage during silage making on silage quality, physical characteristics and the effect of feeding the silages on ruminal fermentation characteristics and microbial protein synthesis.