Effects of stocking rate and physiological state of meat goats grazing grass/forb pastures on forage intake, selection, and digestion, grazing behavior, and performance

TitleEffects of stocking rate and physiological state of meat goats grazing grass/forb pastures on forage intake, selection, and digestion, grazing behavior, and performance
Publication TypeJournal Article
Year of Publication2013
AuthorsAskar, AR, Gipson, TA, Puchala, R, Tesfai, K, Detweiler, GD, Asmare, A, Keli, A, Sahlu, T, Goetsch, AL
JournalLivestock Science
Issue154
Start Page82
Abstract

Effects of forage conditions with different stocking rates on performance and grazing behavior of goats could vary with animal physiological state, as influencing nutrient demand and usage. Therefore, Boer goat does nursing two kids (D; 1 month after kidding), growing wethers (G; 4 month initial age), and yearling wethers (Y; 14 month initial age) grazed 0.4-ha grass/forb pastures, with one animal per type in each pasture (four per stocking rate; SR) for a low SR and two for the high SR. The experiment started in late spring and was 114 days in length, with four periods of 33, 28, 30, and 23 days (P1, P2, P3, and P4, respectively). Data were analyzed by mixed models with a repeated measure of period. Forage mass was 2517, 2433, 2506, and 2452 kg/ha for the low SR and 2680, 1932, 1595, and 1393 kg/ha for the high SR in P1, P2, P3, and P4, respectively (SE=335.1). Botanical composition of the diet determined from n-alkane concentration in simulated grazed forage samples and feces was similar among animal types (P>0.10). Likewise, chemical composition of forage samples did not differ between animal types (P>0.10), with average dietary levels of 11% CP and 53% NDF. Digestibility of OM, determined from the concentration of the n-alkane hentriacontane (C31) in forage samples and feces, was greatest for growing wethers (P