Ovenell K H, Lusby K S, Horn G W, McNew R W
Oklahoma Agricultural Experiment Station, Stillwater 74078-0425.
J Anim Sci. 1991 Jun;69(6):2617-23. doi: 10.2527/1991.6962617x.
Sixteen mature, lactating (453 kg) and 16 nonlactating (487 kg) Hereford and Angus x Hereford cows were used to determine effects of different dietary supplements and lactational status on forage intake, digestibility, and particulate passage rate. Supplement treatments and amounts fed (kg/d) were as follows: control, 0; and equal daily amounts of CP from soybean meal (SBM), 1.36; wheat middlings (WM), 3.41; or a blend of corn and soybean meal (corn-SBM; 22% corn and 76% SBM), 3.41. Cows were fed supplements at 0800 and had ad libitum access to prairie hay (4.9% CP) in stalls from 0800 to 1100 and from 1300 to 1600 for three 17-d periods. Lactational status and supplement type did not interact (P greater than .50) for hay DMI, DM digestibility, or particulate passage rate. Cows fed SBM ate more hay DM (P less than .01) and had greater hay DM digestibility (P less than .01) than did cows in other treatment groups. Average hay DMI (kg/100 kg of BW) was 1.95, 2.16, 1.94, and 1.89, and hay DM digestibility was 52, 61, 55, and 53% for control, SBM, WM, and corn-SBM supplements, respectively. Total diet DM digestibility was increased by supplementation (P less than .01), but no differences (P greater than .18) were observed among supplements. Lactating cows ate more (P = .13) hay DM (2.11 vs 1.87 kg/100 kg of BW) and had greater (P less than .05) fecal output (4.6 vs 4.3 kg/d) than did nonlactating cows. Dry matter digestibility and particulate passage rate were not affected (P greater than .35) by lactational status.(ABSTRACT TRUNCATED AT 250 WORDS)
选用16头成熟的、处于泌乳期（体重453千克）和16头非泌乳期（体重487千克）的赫里福德牛以及安格斯×赫里福德杂交母牛，以确定不同日粮补充剂和泌乳状态对牧草采食量、消化率和颗粒通过率的影响。补充剂处理及饲喂量（千克/天）如下：对照组，0；豆粕（SBM）提供等量的粗蛋白，1.36；小麦麸（WM），3.41；或玉米与豆粕的混合物（玉米-SBM；22%玉米和76%豆粕），3.41。每天08:00给母牛饲喂补充剂，从08:00至11:00以及13:00至16:00，母牛可在牛栏中自由采食草原干草（粗蛋白含量4.9%），共进行三个为期17天的阶段。泌乳状态和补充剂类型在干草干物质采食量、干物质消化率或颗粒通过率方面不存在交互作用（P大于0.50）。与其他处理组的母牛相比，饲喂豆粕的母牛采食更多的干草干物质（P小于0.01），且干草干物质消化率更高（P小于0.01）。对照组、豆粕组、小麦麸组和玉米-豆粕组补充剂的平均干草干物质采食量（千克/100千克体重）分别为1.95、2.16、1.94和1.89，干草干物质消化率分别为52%、61%、55%和53%。补充剂使总日粮干物质消化率提高（P小于0.01），但各补充剂之间未观察到差异（P大于0.18）。泌乳母牛采食更多（P = 0.13）的干草干物质（2.11对1.87千克/100千克体重），且粪便产量更高（P小于0.05）（4.6对4.3千克/天），高于非泌乳母牛。泌乳状态对干物质消化率和颗粒通过率无影响（P大于0.35）。（摘要截取自250词）
