Whole-crop wheat for dairy cows: effects of crop maturity, a silage inoculant and an enzyme added before feeding on food intake and digestibility and milk production
Whole-crop wheat for dairy cows: effects of crop maturity, a silage inoculant and an enzyme added before feeding on food intake and digestibility and milk production
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用于奶牛的整粒小麦：作物成熟度、青贮饲料接种剂和饲喂前添加的酶对食物摄入量、消化率和产奶量的影响
DOI：
10.1017/s1357729800052474
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
D. Humphries
中科院分区：
文献类型：
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作者：
J. Sutton;R. Phipps;E. Deaville;A. Jones;D. Humphries
连续两年在不同成熟期收获冬小麦，研究全麦成熟期对其营养成分、消化率和饲用价值的影响。在第1年，WCW以301（低干物质（DM））和511（高DM）g DM/kg收获并青贮，以584 g DM/kg收获并在储存前用40 kg尿素处理（尿素处理的WCW）。在收获时用含有布氏乳杆菌的添加剂处理部分高DM WCW。在第2年，WCW以321（低DM）和496（高DM）g DM/kg收获，并在两种作物提供给奶牛之前青贮，在饲喂前在饲料上喷洒或不喷洒纤维分解酶。在这两年中，WCW自由采食，WCW：草青贮DM比例为2：1，每天10 kg鲜重浓缩物，在13或15周的连续设计生产研究中向40头泌乳早期荷斯坦-弗里斯兰奶牛提供，并在4 Feat 4拉丁方实验中向4头瘘管泌乳奶牛提供，以测量饲料消化率。在这两年中，中性洗涤纤维（NDF）含量下降，淀粉含量增加，随着成熟度的推进。在生产试验中，随着成熟期的增加，干物质采食量显著增加（P 0·01），但对产奶量影响不显著。尿素处理的WCW提高了乳蛋白产量。添加剂对食物摄入量或牛奶产量没有影响。在第1年，除淀粉外，所有组分的消化率高DM WCW低于低DM WCW，但尿素处理的WCW只有淀粉和能量的消化率低于低DM WCW组分的消化率。接种剂没有显著效果。在第2年，作物成熟度对消化率没有显著影响，但酶降低了中性和酸性洗涤纤维（NDF和ADF）的消化率（P 0·05）。在第1年，每种饲料混合物提供给绵羊12克DM每公斤活重每天。对DM（P0.05）、有机物（P0.01）和DOMD（DM中可消化的有机物）的消化率有显著影响（P0.01），其中尿素处理的WCW的消化率最高，接种高DM的WCW的消化率最低。NDF和ADF的消化率系数最高的尿素处理的WCW，而淀粉消化率基本上是完全的所有WCW治疗。与基于化学组成的预测值（9.6，10.4和12.4）相比，当用泌乳奶牛（10.4，9.3和9.0）和绵羊（11.4，10.8和10.3）测量时，WCW的代谢能值（MJ/kg校正DM）随着成熟度的增加而降低。它的结论是，食物摄入量增加，推进作物成熟，但牛奶生产的反应很小。对消化率的影响是不一致的，但在奶牛中测得的能量值下降，在这两年推进成熟。随着成熟期的提前，每公顷作物产量的增加可能是影响晚收决定的最重要因素。测试的青贮饲料添加剂是没有好处的。
To measure the effect of stage of maturity of whole-crop (WCW) on its composition, digestibility and feeding value winter wheat was harvested at different maturities in two successive years. In year 1 WCW was harvested at 301(low dry matter (DM)) and 511(high DM) g DM per kg and ensiled and at 584 g DM per kg and treated with 40 kg urea per t DM before being stored (urea-treated WCW). Part of the high DM WCW was treated with an additive containing Lactobacillus buchneri at harvest. In year 2 WCW was harvested at 321 (low DM) and 496 (high DM) g DM per kg and ensiled before both crops were offered to the cows with or without a fibrolytic enzyme sprayed on the forage just before feeding. In both years the WCW was offered ad libitum in a 2: 1 WCW: grass silage DM ratio with 10 kg fresh weight concentrates per day to 40 early-lactation Holstein-Friesian cows in a 13-or 15-week production study with a continuous design and to four fistulated lactating cows in a 4 ✕ 4 Latin-square experiment for measurement of diet digestibility. In both years neutral-detergent fibre (NDF) content decreased and starch content increased with advancing maturity. In the production trials, DM intake increased (P 0·01) with advancing maturity but milk yield was not significantly affected. Milk protein yield was increased by urea-treated WCW. The additives had no effect on food intake or milk production. In year 1, digestibility of all fractions except starch was lower for high DM WCW than low DM WCW but for urea-treated WCW only the digestibility of starch and energy was lower than digestibility of the low DM WCW fractions. The inoculant had no significant effect. In year 2 crop maturity had no significant effect on digestibility but the enzyme reduced the digestibility of neutraland acid-detergent fibre (NDF and ADF, P 0·05). In year 1, each of the forage mixtures was offered to sheep at 12 g DM per kg live weight per day. There were significant treatment effects on the digestibility of DM (P 0·05) and organic matter (OM) (P 0·01) and on DOMD (digestible OM in the DM) (P 0·01) with the highest values being obtained for urea-treated WCW and the lowest for the inoculant-treated high DM WCW. Digestibility coefficients for NDF and ADF were highest for the urea-treated WCW while starch digestibility was essentially complete for all the WCW treatments. The metabolizable energy value (MJ/kg corrected DM) of the WCW decreased with advancing maturity when measured with both the lactating cows (10·4, 9·3 and 9·0) and the sheep (11·4, 10·8 and 10·3) in contrast to the predictions based on the chemical composition (9·6, 10·4 and 12·4). It is concluded that food intake increases with advancing crop maturity but milk production responses are small. Effects on digestibility were inconsistent but the energy value measured in the cows fell with advancing maturity in both years. The increase in crop yield per ha with advancing maturity is likely to be the most important factor influencing the decision to harvest later. The silage additives tested were not beneficial.