Nutritional Value of Raisin by- Product and its Effect on Late Flower Alfalfa Hay Fermentation Profile and Nutrient Availability in Ruminants

Introduction Using agro-industrial by-products in ruminants feeding could help in semi arid climate condition throughout the year. Raisin by-product is produced in huge magnitude in Malayer city, Hamedan province. Local different raisin by-products which produced during machinery cleaning and sorting of sun dried treated grapevine cluster (Vitisvinifera L. cv. Sultana), are as:1) some outer layer of flesh and skin and pedicle of berries; 2) rejected raisins mostly un-ripped berries with their pedicles and 3) peduncles and rachises with their lateral branches of clusters. They may have suitable nutritive value in ruminants. However, their nutrient profile and availability and anti nutrient factors such as lignin and tannin should be considered. Alfalfa hay is usually the important forage used in dairy cow’s diet. However, it has lower fiber digestibility and higher ruminal crude protein degradability. Increasing alfalfa hay fiber digestibility and decreasing ruminal crude protein degradability can help its feeding value. Raisin by-product may help to achieve those in the case of alfalfa hay. The objective of this study was to evaluate the nutritional value of raisin by-product in ruminant feeding compared with late flower alfalfa hay and consideration of its effect on in vitro fermentation of alfalfa hay.
Material and methods Based on completely randomized block design, two original samples (two blocks) for each of alfalfa hay and raisin by-product from local availabilities were collected. In first experiment, chemical and phenolic (total phenol and tannin) composition analysis was measured by two replicates for each block according to AOAC methods. In second experiment, in situ ruminal degradation kinetics of alfalfa hay and raisin by-product was measured using two fistulated Mehraban rams. For ruminal incubation times of 0, 3, 6, 16, 36, and 72 h respectively 2, 2, 4, 6, 8 and 10 filled nylon bags used which randomly assigned in animals. In situ trial was conducted in two runs. Nylon bag residuals from incubation time for each feed block within each run were pooled. In third experiment, gas production kinetics of alfalfa hay, raisin by product and their combination batches as 75:25, 50:50 and 25:75 in dry matter basis were measured at incubation times of 0, 2, 4, 8, 12, 24, 48 and 72 in two runs and with three vials per time of incubation. Orskov and Mcdonal model used to calculate the in situ and gas production parameters. Potential nutrient supply using 24 h cumulative and chemical compositions were measured. Data was analyzed based on completely randomized block design using proc mixed SAS (9.2) which the effect of treatment was as fixed and the effects of block and run were considered as random. The LSD used to compare means differences and level of significant was P≤0.05.
Results and discussion Chemical composition results showed that total phenol and tannin and organic matter content in raisin by-product were significantly higher and dry matter, crude protein, neutral detergent fiber, acid detergent fiber and ash were lower than alfalfa hay (P