Contents lists available at ScienceDirect Animal Feed Science and Technology journal homepage: www.elsevier.com/locate/anifeedsci Effects of replacing dietary maize grains with increasing levels of sugar beet pulp on rumen fermentation constituents and performance of growing buffalo calves H.M. Abo-Zeid a , H.M. El-Zaiat a, ⁎ , A.S. Morsy b , M.F.A. Attia a , M.A. Abaza a , S.M.A. Sallam a a Animal Production Department, Faculty of Agriculture, Alexandria University, Alexandria, Egypt b Livestock Research Department, Arid Lands Cultivation Research Institute, City of Scientific Research and Technological Applications, New Borg El- Arab, Alexandria, Egypt ARTICLE INFO Keywords: Digestibility Egyptian buffalo Growth performance Maize Rumen characteristics Sugar beet pulp ABSTRACT This study was conducted to evaluate the effects of replacing cracked maize with increasing levels of sugar beet pulp (SBP) on nutrients digestibility, blood biochemical and rumen fer- mentation constituents and animal performance of growing Egyptian buffalo calves. Forty male Egyptian buffalo calves (237.2 ± 24.46 kg of initial body weight, IBW) were allocated into a completely randomized design and stratified to one of four experimental diets. The basal diet was isonitrogenous (40:60 forage: concentrate) and was formulated to contain 60% of dietary DM cracked maize replaced by ascending levels of SBP (0, 333, 667, and 1000 g/kg respectively). The study lasted for a period of 143 days from which 21 days for adaptation while the remaining 122 days were used for data collection. Increasing the level of SBP resulted in a quadratic in- crease (P = 0.017) in the average daily gain (ADG) with a linear tendency of increase (P = 0.064) in dietary dry matter intake. A quadratic decrease of feed conversion ratio (FCR, P = 0.005) was observed with the ascending levels of SBP. In addition, the daily intake of or- ganic matter, neutral detergent fiber assayed with heat stable α-amylase and corrected for ash (aNDFom), acid detergent fiber corrected for ash (ADFom) were quadratically (P < 0.01) im- proved upon increasing the dietary SBP level while the daily intake and digestibility of ether extract were declined linearly (P < 0.01). Replacing SBP for maize resulted in linear increase (P < 0.01) in OM, aNDFom, cellulose and hemicellulose digestibility coefficients. Ruminal pH, total short chain fatty acids, proportions of acetate (C2) and butyrate were increased linearly (P < 0.05). In contrast, the proportions of propionate (C3) and isobutyrate were decreased linearly (P < 0.05) upon increasing the levels of SBP. In addition, the C2:C3 ratio and total protozoa were linearly (P < 0.01) increased while the ruminal NH 3 -N concentration was quadratically (P = 0.046) increased as SBP replaced maize in the diet. Furthermore, upon in- creasing the dietary SBP levels, the blood urea-N, cortisol and thyroxin (T4) concentrations were quadratically elevated (P < 0.01). Conversely, linear decreases in creatinine, (P = 0.027) and http://dx.doi.org/10.1016/j.anifeedsci.2017.09.011 Received 17 February 2017; Received in revised form 14 September 2017; Accepted 15 September 2017 ⁎ Corresponding author at: University of Alexandria, Faculty of Agriculture, Department of Animal Production, Aflaton St., El-Shatby, P.O. Box 21545, Alexandria, Egypt. E-mail addresses: hm_elzaiat@yahoo.com, hani.elzaiat@alexu.edu.eg (H.M. El-Zaiat). Abbreviations: ADFom, acid detergent fiber expressed exclusive of residual ash; aNDFom, neutral detergent fiber expressed exclusive of residual ash; ADG, average daily gain; AOAC, association of official analytical chemists; BWG, body weight gain; BUN, blood urea-N; CP, crude protein; C2:C3, acetate to propionate ratio; DM, dry matter; DMI, dry matter intake; EGP, Egyptian pound; FBW, final body weight; FCR, feed conversion ratio; GC, gas chromatography; IBW, initial body weight; Lignin(sa), lignin measured by solubilization of cellulose with sulphuric acid; ME, metabolic energy; MPBW, market price of body weight; MPF, market price of feeds; MT, million ton; NEm, net energy for maintenance; NEg, net energy for gain; OM, organic matter; SBP, sugar beet pulp; SCFA, short chain fatty acids; T3, triio- dothyronine; T4, thyroxine; TMR, total mixed ration Animal Feed Science and Technology 234 (2017) 128–138 0377-8401/ © 2017 Elsevier B.V. All rights reserved. MARK