Submitted to: Journal of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 7/21/1999
Publication Date: N/A
Technical Abstract: Postweaning performance, apparent total tract nutrient disgestibility, and plasma metabolite profiles of growing Spanish (S), Boer X Angora (BA), and Boer X Spanish (BS) castrates were investigated. Kids were weaned at 8 wk of age and fed a commercial goat starter diet (25% CP, 2.71 Mcal/kg DE, 34.7% NDF, and 18% ADF) ad libitum for 16 weeks. Feed intake was recorded daily and BW taken at 2-wk intervals. Digestibility was measured in wk 17 for 5d. Boer X Angora and BS castrates had greater (P <.001) initial and final BW than S(7.3, 7.2, and 6.6 SE .2kg; 24.4, 25.2, and 19.5 SE .25kg, for BS, BA, and S, respectively). Final BW of BA was greater than BS (P <.03). Average daily gain (154, 161, and 117 SE 5.6 g/d), DMI (646, 683, and 522 SE 21.5 g/d), and gain:feed (263, 261, and 235 SE 8.0 g of BW gain/kg of feed consumed) were also greater (P <.05) for BS and BA vs S, respectively. Average daily gain, DMI, and feed:gain were similar (P >.05) )between BA and BS. The rate at which BW and DMI changed over time was greater (P <.001) for Boer crosses than S. Average daily gain increased linearly (P <.001) while feed efficiency decreased (P <.001) linearly and quadratically over the 16 wk feeding period. Genotype had no effect (P >.05) on digestibilities of dietary DM, OM, CP, or gross energy (687 SE 1.4%, 70.6 SE 1.3%, 69.9 SE 1.4% and 69.3 SE 2.4%, respectively). Genotype also had no effect on plasma concentrations of total protein, glucose, or NEFA (P >.05). However, BA had greater (P <.05) concentrations of plasma urea N compared with S and BS (25.5, 19.6, and 21.3 SE 1.0 mg/dL, respectively). Under intensive management, the use of Boer bucks as terminal sires has the potential to produce crossbred kids which grow faster and achieve heavier BW as compared to fullblood Spanish goat kids.