Intake, performance, and blood parameters in young goats offered high forage diets of lespedeza or alfalfa hay

July-born F1 Boer x Spanish (BoerX), Nubian, and Spanish buck kids (n = 18) were used in an experiment to evaluate the use of lespedeza hay in goat diets. Bucklings were weaned at 60 d of age and maintained on pasture and in pens, before being assigned to the experiment at 6 months of age. Kids were randomly assigned to six pens and stratified by breed. The two diets were ad libitum: (1) sericea lespedeza [Lespedeza cuneata (Dum.-Cours) G. Don; LESP] hay, or (2) alfalfa (Medicago sativa L.; ALF) hay. All animals received a 16% crude protein (CP) corn/cottonseed-based supplement offered at 0.5% of body weight (BW) per head/d. Total dry matter intake (DMI) was higher (P < 0.001) for LESP-based (42.1 g/kg BW per day) than for ALF-based (38.7 g/kg BW per day) diets, and increased with time on trial for LESP, but not ALF (diet × time interaction: P < 0.05). Bucks offered ALF had higher average daily gain (ADG; 103 versus 56 g/d; P < 0.01) and final BW (31.3 versus 26.6 kg; P < 0.05) than those offered LESP. Initial body weights were higher (P < 0.001) for Nubian (24.7 kg) compared to BoerX (18.5 kg) or Spanish (19.7 kg) which were similar. This same trend was observed for final body weights (P < 0.05; Nubian 33.4 kg; BoerX 25.9 kg; Spanish 27.3 kg). There were no breed differences (P > 0.10) in ADG (mean 79 g/d). Bucks offered the ALF-based diet had higher (P < 0.001) plasma concentrations (mg/dl) of blood urea nitrogen (BUN; 21.1 versus 10.7) and glucose (67.7 versus 59.5) and lower (P < 0.001) creatinine (0.53 versus 0.62 mg/dl) compared to kids offered the LESP-based diet. Blood glucose concentrations were highest (P < 0.001) for Nubian (66.3 mg/dl) and lowest for Boer cross (60.9 mg/dl); Spanish was intermediate (63.6 mg/dl). Creatinine levels were similar among breeds (mean 0.57 mg/dl). More research is needed to evaluate goat breed, forage species, stage of forage maturity, condensed tannins, and supplementation effects on nutrient utilization by finishing goats.