Growth performance and carcass characteristics of lambs fedhalophytes as a partial or whole replacement of berseem hay

Abstract

tThe aim of this study was to evaluate partial or whole substitution of berseem hay withAtriplex nummularia (AT) and/or Acacia saligna (AC) in the diet of Barki lambs. Thirty-sixmale lambs (body weight 26.5 ± 1.1 kg and age 13 ± 1.1 months) were divided into fourgroups and fed: (1) the control diet (70% concentrate mixture and 30% berseem hay), (2)AT (AT15 diet) or (3) AC (AC15 diet) replaced 50% of berseem hay in the diet, or (4) ATand AC at a ratio of 1:1 to replace 100% of berseem hay (TC30 diet), respectively. Lambgrowth performance, rumen fermentation, blood chemistry, carcass characteristics andintestine histological properties were investigated. Dry matter intake, daily weight gainand feed conversion were measured every two weeks (period) for 10 weeks. Interactionswere observed (P < 0.05) between period × diet for these measurements and period affected(P < 0.05) daily weight gain and feed conversion. Lambs in the AT15 and AC15 groups hadincreased (P < 0.05) dry matter intake (g/lamb/day), water consumption (L/lamb/day), dailyweight gain (g/lamb/day) and feed conversion (feed intake/body weight gain) during thelast 2, 6, 2 and 8–10 weeks, respectively. The treatments AT15, AC15 and TC30 had decreasedconcentrations (P < 0.01) of ruminal volatile fatty acids, but did not affect ruminal ammonia-N concentrations. Lambs fed the experimental diets had lower (P < 0.05) concentrations ofblood cholesterol, low density lipoproteins and glucose and higher (P < 0.05) concentrationsof serum urea. The treatment AT15 had increased (P < 0.05) gut fill, pelt and mesenteryweights, whereas the treatment AC15 increased (P < 0.05) spleen and lung weight as a per-centage of carcass weight. In regards to the protein content of the 9–11th ribs, the treatmentAT15 was similar to the control, but the AC15 and TC30 were lower (P < 0.05) than the con-trol. Lambs in the treatment groups showed a normal histology of ileum, sub-mucosa andPeyer’s patches. It could be concluded that AT or AC can replace 50% of berseem in the dietof Barki lambs without compromising lamb growth performance.