含有不同比例的混合饲料甜菜顶部-小麦秸秆青贮饲料(BS)的口粮,代替玉米青贮饲料(CS),对30头哺乳期中期的荷斯坦奶牛(均为2级)进行了试验,以测量对饲料消耗的影响,牛奶生产效率,牛奶化学,尿嘌呤衍生物(PD),血液化学,抗氧化剂水平,和体外甲烷(CH4)排放。BS是通过将饲料甜菜顶部与小麦秸秆以9:1的比例混合而制备的,基于鲜重。使用30头母牛(10只动物/处理)和3种处理将实验设计完全随机化(一个28-d周期,21-d适应)。治疗方法为1)仅含CS(25克/100克DM)(CSD)的饮食,2)含有50%CS(12.5g/100gDM)和50%BS(12.5g/100gDM)(CBSD)的饮食,和3)仅含BS的饮食(25g/100gDM)(BSD)。将每只动物(作为实验单元)单独饲养在领带摊位中,并随意获取其饮食。膳食用BS代替50%的CS在产奶量方面没有显着差异,脂肪校正牛奶,脂肪和蛋白质产量,饲料效率,和表观消化率,然而,在饲喂BSD的奶牛中,这些变量较小(P<0.05)。饲喂BSD的奶牛的DM摄入量较少,有机物,粗蛋白,和中性洗涤剂纤维,但更多的草酸摄入量和血尿素-N,与其他奶牛相比。牛奶中脂肪的百分比,蛋白质,乳糖,尿素N,血清葡萄糖,甘油三酯,胆固醇,总蛋白质,白蛋白,球蛋白,Ca,P,以及体外瘤胃pH,不受饮食的影响。在接受CBSD的奶牛的牛奶中,饱和脂肪酸浓度较低,单不饱和FA和多不饱和FA(PUFA)较高,与其他群体相比。在饮食中包含两种BS速率降低了体外气体产生,原生动物数量,与对照相比,CH4排放。饲喂BSD的奶牛尿尿囊素水平降低,PD排泄或吸收,和估计的微生物N合成比对照组和CBSD饲喂组。饲喂CBSD的动物的牛奶和血液总抗氧化能力(TAC)在奶牛中最高。总的来说,在目前的实验条件下,用BS代替50%的膳食CS并不影响产奶量,但增加了牛奶PUFA,以及血液和牛奶TAC,并减少体外CH4的排放,所以建议给泌乳的荷斯坦奶牛喂食。
Rations containing different rates of the mixed fodder beet tops-wheat straw silage (BS), instead of corn silage (CS), were given to 30 mid-lactation Holstein cows (all in parity 2) to measure the effects on feed consumption, milk production efficiency, milk chemistry, urinary purine derivatives (PD), blood chemistry, antioxidant levels, and in vitro methane (CH4) emission. The BS was prepared by mixing the fodder beet tops with wheat straw at a ratio of 9:1 based on fresh weight. The experimental design was completely randomized (one 28-d period with 21-d adaptation) using 30 cows (10 animals/treatment) and 3 treatments. The treatments were 1) a diet containing CS only (25 g/100 g DM) (CSD), 2) a diet containing 50% CS (12.5 g/100 g DM) and 50% BS (12.5 g/100 g DM) (CBSD), and 3) diet containing BS only (25 g/100 g DM) (BSD). Each animal (as an experimental unit) was housed individually in the tie stall and had ad libitum access to its diet. Dietary replacing 50% of CS with BS showed no significant differences in milk production, fat-corrected milk, fat and protein yields, feed efficiency, and apparent digestibility, however, these variables were less (P < 0.05) in the cows fed with BSD. Cows fed on BSD had less intakes of DM, organic matter, crude protein, and neutral detergent fiber but greater oxalic acid intake and blood urea-N, as compared to the other cows. Milk percentages of fat, protein, lactose, urea N, blood serum glucose, triglyceride, cholesterol, total protein, albumin, globulin, Ca, and P, as well as in vitro ruminal pH, were not affected by the diets. Saturated fatty acids concentration was less and monounsaturated FA and polyunsaturated FA (PUFA) was greater in the milk of cows receiving CBSD, compared to the other groups. The inclusion of both BS rates in the diet decreased the in vitro gas production, protozoa number, and CH4 emission in comparison to the control. Cows fed BSD had decreased levels of urinary allantoin, PD excreted or absorbed, and estimated microbial-N synthesis than the control and CBSD-fed groups. The milk and blood total antioxidant capacity (TAC) of the animals fed CBSD was the maximum among the cows. Overall, under the current experimental conditions, replacing 50% of dietary CS with BS did not affect milk production, but increased milk PUFA, as well as blood and milk TAC, and decreased in vitro CH4 emission, so it\'s feeding to lactating Holstein cows is recommended.
The effects of dietary replacing corn silage (CS) with a mixed fodder beet tops-wheat straw silage (BS) on feed consumption and milk production efficiency, milk chemistry, estimated microbial-N synthesis, blood chemistry, and the blood and milk antioxidant status of lactating Holstein cows were assessed. Replacing 50% of CS with BS increased milk polyunsaturated fatty acids (PUFA) concentration, and antioxidant capacity in blood and milk, but decreased in vitro methane production. There were no negative effects of partially feeding BS on intake, nutrient digestibility, animal performance, and blood metabolites. Therefore, replacing 50% of CS with BS is recommended in the diet of lactating Holstein cows.