奶牛采食含有玉米加工副产品日粮时的氮利用、养分消化率和嘌呤衍生物的排泄。

Nitrogen utilization, nutrient digestibility, and excretion of purine derivatives in dairy cattle consuming rations containing corn milling co-products.

机构信息

Department of Animal Science, University of Nebraska, Lincoln 68583-0908, USA.

出版信息

J Dairy Sci. 2010 Aug;93(8):3641-51. doi: 10.3168/jds.2009-2598.

DOI:10.3168/jds.2009-2598

PMID:20655434

Abstract

The objectives of this experiment were to determine the effects of feeding a combination of modified wet distillers grains with solubles (WDGS) and wet corn gluten feed (WCGF) on nutrient digestion, purine derivative excretion, and N utilization. Multiparous (n=20) and primiparous (n=20) cows were arranged in a replicated 5 x 5 Latin square with 21-d periods. Animals were fed one of 5 treatment diets during each period: 1) 0% co-products (control); 2) 15% WDGS (15WDGS); 3) 15% WCGF (15WCGF); 4) 7.5% WDGS and 7.5% WCGF (15MIX); and 5) 15% WDGS and 15% WCGF (30MIX; dry matter basis). A portion of forages, corn, and soy-based protein was replaced with WDGS, or WCGF, or both. Dry matter intake was greater for 15WDGS (25.1 kg/d) and 30MIX (25.5 kg/d) than for control (22.4 kg/d), 15WCGF (23.2 kg/d), or 15MIX (23.5 kg/d). Dry matter digestibility was greatest for 15WCGF and 30MIX (63.6 and 64.1%, respectively) and least for 15WDGS (59.8%), and neutral detergent fiber and N digestibility were greatest for 30MIX (50.7 and 68.6%, respectively) and lowest for 15WDGS (41.3 and 61.5%, respectively). Excretion of purine derivatives in urine was greater for co-product treatment diets than for control. Fecal N was greatest for 15WDGS compared with other treatment diets (311.0 vs. 263.3 g/d), whereas urinary N was greatest for 30MIX (330.0 g/d), intermediate for 15WCGF and 15MIX (319.3 and 320.5 g/d, respectively), and lowest for control and 15WDGS (308.5 and 312.2 g/d, respectively). Manure N (fecal+urinary N) was greatest for 15WDGS, intermediate for 15MIX and 30MIX, and lowest for control and 15WCGF. Treatment diets did not differ in 4% fat-corrected milk production. Compared with the ration containing WDGS, the ration with a 30% mixture of WDGS and WCGF improved nutrient digestibility and N utilization with reduced manure N excretion and increased N retention. Thus, it appears feeding WDGS and WCGF in combination reduces some of the negative effects of feeding WDGS alone.

摘要

本实验的目的是确定饲喂组合的改性湿酒糟和可溶物（WDGS）和湿玉米蛋白粉（WCGF）对养分消化、嘌呤衍生物排泄和氮利用的影响。多胎（n=20）和初产（n=20）奶牛按复制的 5 x 5 拉丁方排列，每个周期为 21 天。在每个时期，动物都被喂食 5 种处理日粮中的 1 种：1）0%副产品（对照）；2）15% WDGS（15WDGS）；3）15% WCGF（15WCGF）；4）7.5% WDGS 和 7.5% WCGF（15MIX）；5）15% WDGS 和 15% WCGF（30MIX；干物质基础）。一部分饲料、玉米和基于大豆的蛋白质被 WDGS 或 WCGF 或两者替代。15WDGS（25.1 kg/d）和 30MIX（25.5 kg/d）的干物质摄入量高于对照（22.4 kg/d）、15WCGF（23.2 kg/d）或 15MIX（23.5 kg/d）。15WCGF 和 30MIX 的干物质消化率最高（分别为 63.6%和 64.1%），15WDGS 的最低（59.8%），中性洗涤剂纤维和氮消化率最高（分别为 50.7%和 68.6%），15WDGS 的最低（41.3%和 61.5%）。尿液中嘌呤衍生物的排泄在含有副产品的日粮中大于对照。15WDGS 的粪便氮含量最高，与其他处理日粮相比（311.0 比 263.3 g/d），而 30MIX 的尿氮含量最高（330.0 g/d），15WCGF 和 15MIX 中等（319.3 和 320.5 g/d），对照和 15WDGS 最低（308.5 和 312.2 g/d）。粪便氮（粪便+尿氮）最高的是 15WDGS，15MIX 和 30MIX 中等，对照和 15WCGF 最低。在 4%脂肪校正乳产量方面，处理日粮没有差异。与含有 WDGS 的日粮相比，含有 30% WDGS 和 WCGF 混合物的日粮提高了养分消化率和氮利用率，同时减少了粪便氮的排泄，增加了氮的保留。因此，似乎饲喂 WDGS 和 WCGF 的组合减少了单独饲喂 WDGS 的一些负面影响。