Effect of feeding on reproductive performance in Finnish dairy cows

The effect of 2 types of feeding on the involution of the genital tract and on the fertility was studied in 79 Finnish dairy cows on a research farm. The cows were fed twice a day with home-produced feed in accordance with the Finnish feeding standard. The cows were divided according to the type of feed into a hay-urea group and a silage group. The cows were examined clinically by rectal palpation 3 times a week during 8 weeks postpartum. The time required for the complete involution of uterus and cervix was recorded. The cows in the silage group had a significantly longer time in uterine involution, a lower fertility rate at first insemination and a longer interval from calving to conception than those in the hay-urea group. The pregnancy rate in the first insemination was in the hay-urea group 91% and in the silage group 57%. The interval between calving and the first insemination was shorter in the hay-urea group than in the silage group: 71.4 +/- 10.6 and 74.0 +/- 10.3 days, respectively. The interval between calving and conception was in the hay-urea group significantly (p less than 0.01) shorter than in the silage group; 74.8 +/- 15.1 and 89.5 +/- 24.4 days, respectively.     

哺乳动物妊娠期钙代谢的研究进展

哺乳动物体内的钙代谢通常包括钙平衡和钙稳态。钙平衡是指体内总钙含量保持相对恒定的状态,钙稳态则指细胞内外的钙离子浓度保持稳定。肾脏、肠道、骨骼及雌性动物乳腺是动物体钙代谢的主要器官,其中存在着许多精细而复杂的调控网络。妊娠期钙代谢紊乱会严重影响母畜及胎儿的营养健康,维持体内钙代谢稳态对围产期哺乳动物尤为重要。本文综合近年来国内外妊娠期哺乳动物钙代谢相关研究,从不同组织器官钙代谢情况及钙代谢过程中重要的调节因子的调控作用进行综述,旨在为妊娠期哺乳动物钙代谢调控相关研究提供思路。     

叶面施钙对猕猴桃钙含量、品质及贮藏性的影响

为提高猕猴桃营养价值,改善果实品质和贮藏性。以“贵长”猕猴桃为试验材料,采收前对叶面喷施不同钙,比较不同处理果实钙含量、品质及贮藏性指标。结果表明,叶面施钙能提高猕猴桃果实钙含量,提升猕猴桃综合品质,其中Ca(NO3)2 处理的猕猴桃平均单果重、果形指数和维生素C均大于其它处理,分别达87.49g、 1.72和213.54mg/100g;叶面喷施Ca(C6H11O7)2 的果实糖酸比达11.42;叶面施钙能降低猕猴桃维生素C和可滴定酸含量的下降速度,推迟可溶性固形物和可溶性总糖含量的峰值期,延缓猕猴桃软化。试验表明,叶面施钙能提高猕猴桃营养价值,提高品质和贮藏性,提升商品性。     

钙生境对紫花苜蓿种子萌发生长特性影响及其耐钙综合评价研究

为筛选出耐钙胁迫的紫花苜蓿（Medicago sativa）品种,本研究选取14个紫花苜蓿品种作为试验材料,配制不同Ca²⁺浓度的霍格兰营养液模拟钙生境进行种子萌发试验,通过测定发芽指标、形态指标、生物量指标,基于隶属函数法综合评价紫花苜蓿品种间种子萌发期的耐钙性。结果表明:在0~320 mmol·L^-1钙浓度下,大多数紫花苜蓿品种的发芽率、胚芽长等指标随钙浓度提高先略微上升后呈下降趋势,且钙浓度越高下降幅度越大,其中在120 mmol·L^-1钙浓度下各品种间发芽率产生显著差异（P<0.05）,可视为拐点浓度;最适宜的发芽浓度为0.4~4 mmol·L^-1,半致死浓度为120~160 mmol·L^-1,致死浓度为160~200 mmol·L^-1。通过聚类分析将14个品种的抗钙能力划分为5个类群。基于隶属函数综合评价结果筛选出耐钙能力最强的品种为‘WL525HQ’,最弱的为‘WL656HQ’。研究结果表明紫花苜蓿‘WL525HQ’品种在高钙胁迫下具有较强的耐钙性和生存能力,建议将该品种作为岩溶区紫花苜蓿牧草种植推广的首选品种。     

哺乳母猪钙磷营养研究进展

对20年来哺乳母猪钙磷需要及其相关方面的研究进展作了全面综述.包括哺乳母猪钙磷需要的建立,对钙磷需要的探讨,钙磷的吸收和代谢,钙磷的生物效价,钙磷比例问题,母猪钙磷缺乏症,影响钙磷需要的因素.     

饲粮锌和钙水平对产蛋鸡生产性能、血液生化指标和组织中锌含量的影响

试验在玉米-豆饼型基础饲粮中(含锌29.2ppm)添加不同水平锌和钙研究了饲粮锌和钙水平对蛋用型鸡产蛋期生产性能、血液生化指标和组织中锌含量的影响。结果表明:1.仅喂未加锌的基础饲粮的试验鸡开产晚(P<0.05),产蛋率低(P<0.05)、蛋重小(P<0.05)、产蛋量少(P<0.01)、饲料利用效率差(P<0.01)、破壳率高(P<0.01)。饲粮加锌1000ppm与加锌40ppm对照相比,生产性能无显著差异。饲粮高钙对产蛋鸡生产性能无不良影响。2.血清碱性磷酸酶活性随饲粮加锌水平的提高而显著提高(P<0.01),但不受饲粮钙水平显著影响(P>0.05)。饲粮加锌1000ppm使血清总蛋白含量(P<0.01)、血清白蛋白和球蛋白含量(P<0.05)显著降低。饲粮高钙使血清总蛋白含量(P<0.01)和白蛋白含量(P<0.05)显著降低,而球蛋白含量不受影响(P>0.05)。3.随饲粮加锌水平的提高,肝脏(P<0.01)、胰脏(P<0.01)和胫骨(P<0.01)中锌含量大幅度升高;血液(P<0.01)、肾脏(P<0.01)和肺脏(P<0.05)中锌含量升高幅度较小;而输卵管(P>0.05)、心脏(P>0.05)和肌肉(P>0.05)中锌含量无显著变化。饲粮高钙使肝脏(P<0.05)和肌肉(P<0.01)中锌含量显著降低,对其它器官无显著影响(P>0.05)。     

仔猪钙需要量的研究

本试验研究了饲粮中不同钙水平（０．１３％,０．３５％,０．５７％,０．６８％,０．７４％,０．８０％）对７～２２ｋｇ三元杂交（杜×大×长）仔猪的生长性能、骨骼和血清有关指标的影响。结果表明,饲粮中钙水平对仔猪平均日增重、采食量和饲料利用率（Ｇ／Ｆ）都无显著影响（Ｐ＞０．０５）,但０．５７％～０．８０％钙水平组略优于０．１３％～０．３５％钙水平组。随着饲粮中钙水平的升高,单位体重的脱脂干股骨重及其中灰分、钙和磷含量、血清钙浓度上升,到０．７４％钙水平组达到最高,０．８０％钙水平组又降低。其中,各组间单位体重的脱脂干股骨重无明显差异（Ｐ＞０．０５）,而０．７４％钙水平组脱脂干股骨中灰分和磷含量分别显著或极显著高于０．１３％和０．３５％钙水平组（Ｐ＜０．０５,Ｐ＜０．０１）,０．５７％、０．６８％、０．８０％钙水平组显著高于０．１３％钙水平组（Ｐ＜０．０５）。０．７４％钙水平组脱脂干股骨中钙含量和血清钙浓度显著高于其他组（Ｐ＜０．０５）。饲粮钙水平对血清中碱性磷酸酶（ＡＬＰ）活性无显著影响（Ｐ＞０．０５）。因此认为,７～２２ｋｇ仔猪钙需要量为０．７４％。     

Intake and ruminal digestion determined using omasal and reticular digesta samples in cattle fed diets containing sugar cane in natura or ensiled sugar cane compared with maize silage

Sugar cane is widely used in an in natura forage in tropical countries, but the adoption of silage methods facilitates the preservation of its nutritional value and improves the logistics of its use. To explain differences in performance using alternative forages, it is important to conduct studies that evaluate the various digestion sites for the nutrients provided in diets. However, considering that the collection of omasal digesta is quite laborious and requires the use of a vacuum pump, reticular sampling has been suggested as a promising alternative. Thus, the objective of this study was to evaluate the intake and ruminal digestibility obtained from samples of digesta collected in the reticulum and omasum of cattle fed different diets. Five rumen-fistulated crossbred cattle with an average initial live weight of 336±16.6 kg were used, being distributed in a 5×5 Latin square design. Five diets were evaluated, which contained 60% forage and 40% concentrate on dry matter basis using different forages: maize silage (CS); sugar cane in natura (SCIN); sugar cane silage (SCS0%); sugar cane silage treated with 0.4% calcium oxide (SCS0.4%) or 0.8% calcium oxide (SCS0.8%) on wet basis. The percentage of crude protein (CP) in all of the forages was corrected to 11% based on dry matter (DM) using a mixture of urea/ammonium sulfate (9:1). Six collections of reticular and omasal digesta were obtained over three days at 12 h intervals. To calculate the flow of reticular and omasal nutrients, a double marker system was employed, using cobalt–EDTA and indigestible neutral detergent fiber (NDFi) as markers. The reticular and omasal digesta were similar (P>0.05) to estimate ruminal digestibility of DM, organic matter (OM), CP, neutral detergent fiber (NDF) and non-fiber carbohydrates (NFC). However, the ruminal digestibility of ether extract (EE) and the intestinal digestibility of CP and EE differed (P<0.05) between sampling sites. The results indicate that the omasal digesta is more suitable than the reticular digesta for measuring the ruminal digestion of diet components.