Nutritive value of lentil and vetch straws as compared with alfalfa hay and wheat straw for replacement ewe lambs

Abstract

The objective of this study was to compare the nutritive value of lentil straw (LS) and vetch straws (VS) with alfalfa hay (AH) and wheat straw (WS). Forty Awassi ewes (body weight (BW)=56.2 kg) were assigned randomly to four dietary treatments (10 ewes per treatment) for 6 weeks using a complete randomize design. In each dietary treatment, ewes were fed 550 g per day of concentrate mix formulated to supply 40% of the metabolizable energy requirement. After the consumption of the concentrate mix, ewes had ad libtum access to AH, LS, VS, or WS. Forage intake, total dry matter intake (DMI), and organic matter intake (OMI) were higher for AH and LS and lowest for WS. Final weight of ewes fed AH and LS diets were higher ( P<0.05) than VS and WS diets. However, ewes fed VS diet gained more weight (2.5 kg) than ewes on WS diet (0.2 kg). Dry matter digestibility was higher for the AH and LS diets (59.4%), and lowest for WS diet (49.6%). The VS diet had an intermediate value (54.4%). Ruminal passage rate was higher for AH and LS (3.4% per hour) compared with WS (1.9% per hour). Eating time for the AH diet was lowest compared with the rest of the forages. Eating time, expressed as minutes per kilogram NDF intake, was highest for WS and VS diets (680 min) compared with AH and LS diets (535 min). WS diet required more time for rumination (395 min per day) compared to AH, LS, and VS diets. However, ewes on VS diet spent more time ruminating per kilogram NDF consumed (954 min) compared with WS, LS, and AH diets (901, 617, and 597 min, respectively). These results were significant and demonstrate that the nutritive value of LS is greater than VS and close to the nutritive value of AH. VS nutritive value is slightly greater than WS.