An Interconnection between Elevated SCC Levels in Milk around the First Artificial Insemination and Pregnancy Rate in Dairy Cows

The aim of this study was to evaluate the impact of the somatic cell count (SCC) levels measured at 28-test-day intervals or pregnancy rate at the first artificial insemination of Holstein Friesian cows. All necessary information was taken from test day and farm records. Levels of SCC in milk, 30 days before, and 30 days after the first artificial insemination (FAI) date were divided into 4 categories and their interconnection with pregnancy rate (PR) at FAI was evaluated by applying logistic models. A SCC threshold of 150.000 cells/ml of milk was used to differentiate uninfected udders and infected udders of Holstein Friesian cows. A level of SCC > 150.000 cells/ml in milk, and a level of SCC < 150.000 cells/ml before and after FAI respectively were considered udders with new infections. A level of SCC > 150.000 cells/ml in milk before FAI as well as after FAI, was considered chronically infected udders or subclinical intramammary infections (IMI). Data from 792 FAIs from farm and test day records over a 4-year period (2019-2022) were evaluated. The outcome of this study revealed that the risk for low PR at the first AI was increased in cows with infected udders (OR = 1.33, CI 0.99 - 1.78), compared with uninfected udders. Increased levels of SCC after FAI had a negative effect on PR, while before FAI was not affected. To achieve a good PR, mastitis control measures must be fully adopted to a large extent around the first AI.

Assessment on Energy Self-Sufficiency Rate for Building Integrated Photovoltaics and Fuel Cell System in Japan

A building integrated photovoltaic (PV) and fuel cell (FC) system is proposed for assessment of the energy self-sufficiency rate in a city in Japan. The electricity consumed in the building is mainly supplied by solar panels, while the gap between the energy demand and supply is solved by the FC that is powered by the H2 produced by water electrolysis with surplus power of PV. A desktop case study of using the proposed system in Tsu city which is located in central part of Japan, has been conducted. The results found that the self-sufficiency rates of PV system to electricity demand of households (RPV) during the daytime in April and July are higher than those in January and October. The results also reveal that the self-sufficiency rate of FC system to the electricity demand (RFC) is 15% - 38% for the day when the mean amount of horizontal solar radiation is obtained in January, April, July and October. In addition, it is found the optimum tilt angle of solar panel installed on the roof of the buildings should be 0 degree, i.e., placed horizontally.

Evaluation and application of a milk antibody ELISA for assessing the prevalence and incidence of bovine tuberculosis in dairy herds in Hubei Province,China

Bovine tuberculosis(bTB)is a chronic zoonotic disease that is endemic in China.Current in-vitro tests for bTB are mainly based on blood assays.Collection of samples results in some stress to the sampled cattle and associated economic losses for the herd owner.This study was designed to investigate the relationship between milk and serum antibody tests for bTB in dairy cows using 85 cows with milk and corresponding blood samples.Totally 4,395 milk samples were used to assesse the apparent(test)prevalence and incidence of bTB using the milk antibody ELISA.The association between levels of bTB milk antibody and milk quality was also evaluated.Milk and serum antibody tests showed a good correlation with a 87.5%(95%CI:61.7%,98.4)positive agreement and 98.7%(95%CI:95.4,99.8)negative agreement.The animal level lactoprevalence ranged from 0.3%(95%CI:0,1.2)to 33.3%(95%CI:26.6,40.6)in different farms and the incidence rate ranged from 0 head/cow-month(95%CI:0,0.02)to 0.04 head/cow-month(95%CI:0.02,0.07).Twenty percent of sampled farms met the criteria for bTB control in China.The prevalence on large-scale farms was lower(p<0.001)than on small farms.The bTB milk antibody levels had a negative correlation with milk yield and a positive correlation with somatic cell count(SCC),milk protein percentage(MPP)and percentage of total solids(TS).According to this research,milk ELISA could be used as a supplement of blood samples to assist in the surveillance for bTB and for alerting control and eradication of bTB.

稻草和紫云英协同还田下钾肥施用量对水稻产量及土壤供钾能力的影响

[目的]水稻生产对钾素的需求量大,研究稻草和紫云英协同还田条件下不同施肥处理对水稻产量和土壤钾素形态变化的影响,旨在保障我国南方水稻的高产和土壤钾素高效利用。[方法]不同轮作模式钾肥定位试验位于中国农业科学院红壤实验站内(始于2016年)。试验处理包括不施肥和冬闲(CK)、氮磷钾肥和冬闲(F)、氮磷钾肥和冬种紫云英(CM)、氮磷钾肥配合稻草还田和冬种紫云英(RCM)、氮磷减钾50%配合稻草还田和冬种紫云英(50%KRCM)。在试验第3年(2019年)于水稻收获后调查分析水稻产量和钾素含量,以及耕层土壤中速效钾和缓效钾含量,计算水稻钾素吸收量、钾素生理效率和钾素表观平衡,并进一步探讨水稻产量和钾素各指标之间的相关性。[结果]与CK处理相比,紫云英轮作显著提高水稻年产量,增幅以RCM、50%KRCM较高,分别为59.4%和59.7%。两者协同还田和紫云英单独还田均可显著提高有效穗数,相比化肥冬闲处理(F),增幅为53.1%~63.3%,在稻草和紫云英协同还田下,减钾对水稻产量构成因素的影响不明显。和F处理相比,RCM、50%KRCM处理显著提高了土壤速效钾和缓效钾含量,增幅分别为87.6%、41.1%和14.0%、12.1%,紫云英单独还田(CM)可显著提高土壤速效钾含量,对缓效钾含量的影响不显著。与RCM处理相比,50%KRCM处理的土壤速效钾含量显著降低了24.8%,缓效钾含量没有显著变化。和CK处理相比,RCM处理显著提高了稻谷含钾量,增幅为6.7%,4个施肥处理均显著提高了稻草和稻谷吸钾量,钾素表观平衡均表现为盈余,RCM和50%KRCM处理的钾素盈余量高于CM处理,但50%KRCM处理的钾素盈余量比RCM处理降低了119.7 kg/(hm^(2)·a)。钾素盈余量与土壤速效钾含量变化呈显著正相关,钾素盈余量每增加1 kg/(hm^(2)·a),土壤速效钾含量提高0.25 mg/kg。施肥降低了钾素生理效率,CM、RCM和F处理的钾素生理效率比CK降低了10.3%~15.5%。土壤速效钾含量、植株总吸钾量、钾素表观平衡和水稻产量之间均显著正相关,植株总吸钾量每增加1 kg/hm^(2),水稻产量提高30.5 kg/hm^(2),钾素表观平衡每增加1 kg/(hm^(2)·a),水稻产量提高9.5 kg/hm^(2)。[结论]稻草和紫云英协同还田可增加水稻有效穗数进而提高稻谷产量,增加钾素盈余量可提高土壤速效钾和缓效钾含量,两者协同还田提升水稻产量和土壤供钾能力的作用优于紫云英单独还田。稻草和紫云英协同还田条件下减少钾肥施用量,显著降低钾素盈余量,但没有降低土壤钾素的供应能力,因此,可适当减少钾肥的施用量。

高、低乳脂率哈萨克马血浆代谢组比较分析

本研究旨在分析不同乳脂率哈萨克马血浆代谢物的差异,筛选出高乳脂率哈萨克马血浆中的标志代谢物,为高乳脂率哈萨克马的选育提供数据支撑。选取年龄、胎次、体况相近,饲养管理条件一致的泌乳期哈萨克马12匹,采集产后第30~105天的乳样和血样各288份。根据测定的乳脂率结果,将乳脂率高(≥1.84%)的6匹哈萨克马的血样组成高乳脂率组,乳脂率低(≤0.90%)的6匹哈萨克马的血样组成低乳脂率组。之后,通过非靶向液相色谱-质谱(LC-MS)代谢组学技术分析血样本中的血浆代谢物。结果显示:从高、低乳脂率哈萨克马血浆中共检测出53种差异代谢物。高乳脂率哈萨克马血浆中花生四烯酸、D-赤式-1-磷酸鞘氨醇、前列腺素、5-羟基吲哚-3-乙酸、血栓素B2、尿酸等36种物质的浓度显著高于低乳脂率哈萨克马(P<0.05),L-焦谷氨酸、D-果糖-6-磷酸、生物素和D-高半胱氨酸等17种物质的浓度显著低于低乳脂率哈萨克马(P<0.05)。这些差异代谢物主要富集在花生四烯酸代谢、亚油酸代谢、嘌呤代谢、半乳糖代谢及甘氨酸、丝氨酸和苏氨酸代谢等代谢途径。本研究结果可为深层次探究乳脂的合成以及进一步提升马乳品质提供理论基础。

荷斯坦牛关键奶流速指标筛选及影响因素分析

【目的】本研究旨在探究挤奶流速指标的群体表型变化规律、指标间相关性及主要影响因素,筛选荷斯坦牛关键奶流速指标。【方法】本研究收集了北京地区某规模化牧场2162头泌乳牛1181628条奶流速数据,包含班次奶量及11项奶流速指标(平均流速、挤奶时长、高峰流速、慢速出奶时间占比、脱杯流速、0―15 s流速、15―30 s流速、30―60 s流速、60―120 s流速、前2 min产量和前2 min产量占比),并对班次奶量与上述奶流速指标进行了正态性检验、回归分析、相关性分析,以及影响因素分析。【结果】班次奶量与11项奶流速指标均呈正态分布;其中0―15 s流速、15―30 s流速、30―60 s流速、60―120 s流速、前2 min产量、高峰流速、平均流速和挤奶时长与班次奶量呈正向回归关系,且在各因素水平下变化规律一致;各指标间均存在显著的相关关系(P<0.05),相关系数在—0.80~0.95之间;相关性分析结果表明,平均流速和前2 min产量可作为关键奶流速指标,随着班次奶量的增加均呈现逐渐增加的规律,且在不同年份、季节、胎次、泌乳阶段和挤奶班次均差异显著(P<0.05)。【结论】平均流速和前2 min产量可作为奶流速指标考核的关键指标,但在实际生产管理中,需根据牛群结构和环境变化来设定指标的参考值。随着精细化管理,对于平均流速和前2 min产量可以逐步设定更高参考阈值来获取更高的产奶量,进而增加经济效益。

奶酵益-X6对泌乳牛饲料消化率、采食量和产奶量的影响

[目的]为验证奶酵益-X6对奶牛消化率、采食量和产奶量的影响;[方法]采用随机对照试验方法。[结果]试验组粪便评分均有明显好转,对照组平均干物质采食量增加1.39 kg,试验组平均干物质采食量增加1.87 kg,同比增加0.48 kg(P<0.05)。对照组平均泌乳单产增长2.51 kg,试验组平均泌乳单产增长3.48 kg,同比增长0.97 kg(P<0.05)。[结论]奶酵益-X6对泌乳牛消化率、采食量、产奶量均有明显改善,能维持泌乳牛胃肠道微生物菌落正常功能,改善瘤胃健康状况和有效促进泌乳量,具有独特效果,深受养殖场青睐。

母乳嗅觉刺激联合音乐干预对静脉穿刺新生儿镇痛及穿刺成功率的影响

目的:探讨母乳嗅觉刺激联合音乐干预对静脉穿刺新生儿镇痛及穿刺成功率的影响。方法:选取2021年12月-2023年12月于本院行静脉穿刺的新生儿102例,分为观察组和对照组各51例,两组均给予常规静脉穿刺方法,观察组同时给予母乳嗅觉刺激联合音乐干预。比较两组新生儿疼痛评估量表(NIPS)评分、新生儿面部编码系统(NFCS)评分、新生儿哭闹开始时间和持续时间、一次穿刺成功率、心率(HR)、血氧饱和度(SpO_(2))和穿刺相关并发症。结果:观察组穿刺中、穿刺1 min和2 min后的NIPS评分(4.83±0.74分、2.35±0.67分、0.78±0.40分)、NFCS评分(5.02±1.14分、3.18±0.75分、1.04±0.33分)、哭闹持续时间(54.3±7.2s)、HR(148.1±4.9次/min、149.3±4.8次/min、142.1±4.2次/min)、穿刺相关并发症发生率(5.9%)均低于对照组(5.32±0.88分、3.49±0.56分、1.43±0.47分、5.78±1.09分、4.22±0.93分、1.51±0.48分、110.82±12.28 s、153.8±5.2次/min、155.4±4.9次/min、146.3±4.2次/min、19.6%),新生儿哭闹开始时间(2.8±0.4 s)晚于对照组(2.1±0.2 s),一次穿刺成功率(96.1%)及穿刺中、穿刺1 min和2 min后的SpO_(2)(95.8%±1.9%、95.2%±1.8%、95.0%±1.7%)均高于对照组(82.4%、94.5%±1.7%、94.0%±1.6%、93.6%±1.6%)(均P<0.05)。结论:母乳嗅觉刺激联合音乐干预可有效减轻新生儿对静脉穿刺的疼痛感知,减少新生儿的哭闹时间,有利于提高一次穿刺成功率,降低穿刺相关并发症风险。

口腔运动干预方案在早产儿经口喂养中的应用价值

目的:探讨口腔运动护理干预对早产儿经口喂奶量变化趋势的影响及其应用效果。方法:采取便利抽样法,选取2019年6月—2020年6月样本医院收治的110例早产儿作为研究对象,按随机数表法分为对照组和运动组,每组各55例。对照组进行早产儿常规喂养护理干预,运动组采取口腔运动护理干预。比较两组早产儿经口喂奶比变化趋势、喂养达标情况。结果:干预后1 d、2 d、3 d、4 d、5 d、6 d、7 d,两组早产儿的经口喂奶比呈不断升高趋势,其中运动组干预后7 d内各时间点的经口喂奶比均高于对照组,差异有统计学意义(F=1 447.002,P<0.05);运动组的喂养达标率高于对照组,差异有统计学意义(χ^(2)=4.356,P<0.05);运动组的早产儿喂养效率和吸吮效率高于对照组,差异有统计学意义(t=12.580、10.074,P<0.05)。结论:口腔运动护理干预对早产儿经口喂奶量变化趋势有积极影响,并可提高其喂养达标率。

干法婴幼儿配方奶粉货架期内维生素衰减研究

本文研究了干法婴幼儿配方奶粉中维生素在24个月货架期内的衰减率。结果显示,衰减最明显的是维生素B_(1)和维生素D,平均衰减率均高于20%;其次是维生素A、维生素E、维生素K_(1)、维生素C,平均衰减率为12.91%~19.78%;维生素B_(6)、维生素B_(12)、叶酸、泛酸的平均衰减率低于精密度,未发生明显衰减,其余维生素未发生衰减。本研究旨在为干法婴幼儿奶粉配方设计提供一定的参考。

玉米籽粒乳线比例与籽粒相关性状的关系

选用3个不同粒型玉米品种马齿型郑单958(ZD958)、半马齿型先玉335(XY335)和硬粒型长单106(CD106)为试验材料,研究玉米籽粒乳线比例与粒长、粒宽、百粒鲜质量、含水率、灌浆速率、脱水速率的关系,以期为玉米最佳收获期的确定和适宜机械粒收玉米新品种的选育提供依据。结果表明,品种对玉米籽粒乳线比例的影响达到显著或极显著水平,XY335籽粒乳线比例增加速率最快,其次是CD106、ZD958。不同粒型玉米品种粒长、粒宽、百粒鲜质量对乳线比例的作用效应不同,粒宽、百粒鲜质量对乳线比例的作用效应较大。籽粒乳线比例与籽粒含水率、灌浆速率、脱水速率总体上呈显著或极显著负相关,含水率与灌浆速率、脱水速率呈显著或极显著正相关,灌浆速率与脱水速率呈极显著正相关。

干法婴幼儿配方奶粉货架期内矿物质衰减研究

为给婴幼儿配方奶粉营养强化剂设计提供参考,研究了干法婴幼儿配方奶粉在常温保存下,24个月货架期末时12种矿物质的衰减情况。结果显示,大部分矿物质较稳定,没有明显衰减,仅有锰、碘和硒衰减率大于检测方法国家标准中的精密度范围要求,判定为有衰减,可能与营养强化剂稳定性不佳、检测误差较大等有关。本研究可以为干法婴幼儿配方奶粉设计中的矿物质衰减分析提供参考。

发酵型雪菊乳饮料的稳定性研究

以发酵型雪菊乳饮料为研究对象,分别加入黄原胶、羧甲基纤维素钠、卡拉胶、蔗糖酯、果胶5种稳定剂进行单因素试验,以沉淀率为评价指标,筛选出影响较大的因素进行正交试验,以期获得最佳复合稳定剂组合,从而提高其稳定性。结果表明,当稳定剂羧甲基纤维素钠的用量为0.10%,蔗糖酯的用量为0.35%,果胶的用量为0.35%时,雪菊乳饮料的稳定性最佳,其沉淀率为0.19%,色泽为黄绿色,未分层,牛奶香与花香和谐,香味浓厚,无异味,无黏稠感。

不同体位护理在早产儿中的应用效果

目的探讨不同体位护理在早产儿中的应用效果。方法选取江苏省昆山市第一人民医院2022年6月至2023年6月收治的70例早产儿为研究对象,按照随机数字表法分为对照组和观察组,各35例。对照组给予常规仰卧体位,观察组给予自由体位,比较两组心率、呼吸频率及每日睡眠时间、每日进奶增长量。结果护理后第3天、第7天观察组心率、呼吸频率低于对照组,每日睡眠时间长于对照组,每日进奶增长量多于对照组(P<0.05)。结论早产儿应用自由体位能够改善心率、呼吸频率、睡眠时间及进奶量。

Relationship of Milk Line Position with Grain Weight and Mechanized Harvest of Summer Corn

To investigate the relationship of milk line position with grain weight and mechanized harvest of summer corn in Huang-Huai-Hai Region, 8 varieties （A, B, C, D, E, F, G, H） with large planting areas were selected to measure the grain filling rate, 100-grain weight, water content and milk line position, and the correlation was analyzed. Results showed that when the milk line position was 90%, the grain filling of all the 8 varieties finished and 100-grain weight reached the highest value, which was 43.02 g. The grain filling time was in positive correlation with 100-grain weight. However, when the milk line position completely disappeared, the 100-grain weight was reduced by 8.66% at most. There was no significant difference during the periods of grain weight rising, but in the periods of grain weight falling, the traits of D, E, H were significantly different with the other varieties, and water loss rate of C and A showed significant difference with the other six varieties. The water content of grain was negatively correlated with milk line position. When the milk line percentage was 90% , the grain water content was less than 30% . The key factor influencing the mechanized harvest of summer corn is harvesting time, rather than the varieties. Moreover, milk-line position of 90% is the best time for harvest; if the harvest is too late, the yield will be reduced with varying degrees.

Energy Assessment of Building Integrated Photovoltaics and Fuel Cell Systems: Design Study for Building(s) of Mie, Japan

A building integrated energy system (photovoltaic (PV) and fuel cell (FC)) is proposed for assessment of the energy self-sufficiency rate in five cities of Mie prefecture in Japan. In this work, it is considered that the electricity requirement of the building is provided by the building integrated photovoltaic (BIPV) system and the gap between the energy demand and BIPV supply is fulfilled by the FC. The FC is powered by the electrolytic H2 produced from the surplus power of PV. A design study of using the proposed system in five cities in Mie prefecture, which are in center part of Japan, has been performed. It has been observed that the monthly power production from BIPV is higher in spring and summer, while it is lower in autumn and winter at all considered locations. The self-sufficiency rate of the FC system is higher with decreasing households’ number and it has been observed that the 12 households are more suitable for full cover of the electricity demand by the combined system of PV and FC. The relationship between the households’ number and self-sufficiency rate of the FC system per solar PV installation area can be expressed by exponential curve. The coefficient of the exponential curve can predict the suitable city for the BIPV system with FC system utilizing electrolytic H2 generated by using excess energy from the PV system.

Energy Characteristics of an Integrated Power Generation System with Photovoltaic and Fuel Cell

An integrated energy system (with photovoltaic (PV) and fuel cell (FC) for building) is proposed and assessed in term of its energy self-sufficiency rate in seven cities (Nagoya, Toyota, Tajimi, Takayama, Ogaki, Hamamatsu, Shizuoka) in Tokai region in Japan in this paper. In this work, it is considered that the electricity requirement of the building for household users is provided by a building integrated photovoltaic (BIPV) system and the gap between the energy demand and BIPV supply is fulfilled by the FC. The FC is powered by the electrolytic H2 produced when PV power was in surplus. Based on the study of applying the proposed system in seven cities, which clarifies the effectiveness of the integrated BIPV, electrolytic H2 and FC power generation system, a universal system model has been developed in this paper. It has been observed that the monthly power production from BIPV as well as FC system are higher in spring and summer, while they are both lower in autumn and winter at all considered locations. The self-sufficiency rate of the FC system is higher with decreasing households’ number and it has been observed that 16 is the most appropriate number of households in a building, whose electricity demand could be fully covered by the integrated PV and FC system. Due to its climate condition, Hamamatsu is the best city in the region for installing the proposed system. The correlation between the households’ number and self-sufficiency rate of the FC system per solar PV installation area can be expressed by the regression curve in the form of y = ax-b well.

高ACE抑制活性乳酸菌的筛选及在乳制品中的应用

从传统食品分离的乳酸菌中筛选对血管紧张素转化酶(Angiotensin converting enzyme,ACE)具有强抑制活性的菌株,同时对目标菌株的发酵特性进行评价,探究发酵乳ACE抑制活性的稳定性。研究发现,瑞士乳杆菌WHH2580在10%脱脂乳中发酵后得到的发酵乳ACE抑制率高达97.10%±1.51%。瑞士乳杆菌WHH2580发酵特性优良,发酵制备的无糖发酵乳经胃蛋白酶和胰蛋白酶处理后ACE抑制率保持在高水平,分别为94.60%±0.43%和87.53%±1.04%。发酵乳室温放置5个月后,ACE抑制率、酸度和pH分别为89.27%±1.15%、(74.5±0.5)°T、4.30±0.00。瑞士乳杆菌WHH2580对青霉素、氨苄西林、亚胺培南、美罗培南、利奈唑胺和万古霉素等多种抗生素敏感。结果表明,瑞士乳杆菌WHH2580菌株特性优良,其发酵乳具有显著的ACE抑制活性,应用于降血压功能发酵乳品的开发具有市场前景。

奶牛乳与血液中酮病预警新指标的研究

[目的]酮病是高产奶牛常发的代谢性疾病,本试验旨在通过分析奶牛泌乳早期的生产性能DHI(奶牛群体改良)以及外周血的血细胞成分分析数据,阐明酮病发生与以上指标的相关性,及早预警牧场牛群酮病的发展。[方法]连续3年(2018—2020年)追踪江苏省境内某规模化牧场高产奶牛产后前3个月酮病高发期的生产性能数据,筛选出25头健康和20头酮病奶牛,进一步采集2020年产后第1个月的外周血进行血细胞分析;通过二元Logistic回归模型分析各指标对酮病的预警作用,通过受试者工作特征(ROC)分析确定各指标对酮病的预警值。[结果]奶牛生产性能的回归分析结果显示:乳脂率与酮病显著正相关,乳糖率与酮病显著负相关;奶牛血细胞成分分析结果表明:淋巴细胞数和嗜酸性粒细胞数是与酮病正相关的指标;进一步相关分析发现:鲜牛乳中乳脂率和血液中淋巴细胞数两项联合指标对奶牛酮病具有显著的预警作用,其中乳脂率的最佳分界值为4.21%,淋巴细胞数的最佳分界值为4.815×109L-1。[结论]生鲜奶中的乳脂率和外周血中的淋巴细胞数可作为奶牛产后发生酮病的预警依据,用于指导牧场及时做好调控管理。

过瘤胃辣椒油树脂对夏季奶牛产奶量、干物质采食量、呼吸频率和血清生化指标的影响

为了研究过瘤胃辣椒油树脂对夏季奶牛产奶量、干物质采食量、呼吸频率和血清生化指标的影响,试验将465头胎次为(2.5±1.3)胎、泌乳天数为(109.0±52.3)d的中国荷斯坦奶牛随机分为2组,每组2个重复,对照组(236头)每个重复118头,试验组(229头)2个重复分别为114头和115头。对照组饲喂全混合日粮(TMR),试验组每头奶牛每天饲喂添加300 mg的过瘤胃辣椒油树脂的TMR。试验期为91 d,分为试验前期(1~30 d)、中期(31~60 d)和后期(61~91 d)三个阶段。试验期间,每天09:00、15:30使用手持温湿度计测定距地面1.8 m处环境温度、相对湿度,计算温湿度指数;每天早晨投料后采集TMR样品,测定各组的干物质采食量,同时记录每天每头奶牛的产奶量和呼吸频率;于正试期第30,60,91天采血,检测血清生化指标;应用Broken-stick回归模型分析温湿度指数与呼吸频率的关系。结果表明:试验期内共有62 d的温湿度指数>72试验前期、中期和后期平均温湿度指数分别为70.61±4.02、75.60±2.84、73.17±2.33,温湿度指数>72分别有11,27,24 d;试验后期奶牛产奶量显著低于试验前期(P<0.05),试验组奶牛试验前、后期产奶量和干物质采食量均显著高于对照组(P<0.05);试验中期奶牛呼吸频率显著高于试验前、后期(P<0.05),试验组奶牛试验前期呼吸频率显著低于对照组(P<0.05),奶牛呼吸频率的温湿度指数阈值由对照组72.13提高至试验组73.27;试验阶段显著影响奶牛血清葡萄糖(GLU)浓度(P<0.05),试验组奶牛试验前期血清ALP活性显著高于对照组(P<0.05),对照组奶牛试验后期血清低密度脂蛋白(LDL)和总胆固醇(CHO)浓度高于试验前期(P<0.05),试验组奶牛试验后期血清LDL浓度显著低于对照组(P<0.05)。说明日粮中添加300 mg/(d·头)的过瘤胃辣椒油树脂能够提高奶牛产奶量和干物质采食量,降低奶牛呼吸频率,提高呼吸频率的温湿度指数阈值,改善血清生化指标,在一定程度上缓解热应激,有益于奶牛的健康养殖。