Applied Animal Science最新文献_第8页

Efficacy of ultrasonography to detect liver abscesses in cattle* 超声检查牛肝脓肿的疗效观察*

IF 1.4 Q3 AGRICULTURE, DAIRY & ANIMAL SCIENCE

Applied Animal Science

Pub Date : 2025-02-01 DOI: 10.15232/aas.2024-02639

A.B. Thompson , T.L. Perkins , T.E. Lawrence , R.G. Amachawadi , T.G. Nagaraja , P.R. Broadway , N.C. Burdick Sanchez , V. Machado , M.S. Grant , M.L. Galyean , K.E. Hales

Objective

Our aim was to evaluate the use of ultrasonography to identify liver abscesses in cattle.

Materials and Methods

Finishing steers (n = 160, mean final BW = 649 kg) were used in Exp. 1 and Exp. 2 (n = 63, mean final BW = 593 kg). Liver abscess images were obtained 24 h before slaughter. Steers in Exp. 3 (n = 40; mean final BW = 168 kg) and 4 (n = 40; mean final BW = 159 kg) were beef × dairy steers used in a study to experimentally induce liver abscesses. Real-time ultrasound imaging of the liver was conducted on the day of slaughter.

Results and Discussion

In Exp. 1, the sensitivity of ultrasonography for detection of liver abscesses in finishing beef steers was 14.6%, and in Exp. 2 the sensitivity was 5.6%. In the lightweight beef × dairy steers, sensitivity was 50% in Exp. 2 and 41.1% in Exp 3. Ultrasound accuracy ranged from 70% to 75% within all 4 experiments. Specificity of ultrasonography ranged from 84.6% to 100% among all experiments.

Implications and Applications

Low sensitivity of detection in all experiments indicates ultrasonography has limited value for detecting liver abscesses in live cattle. Nonetheless, the greater specificity observed indicates that ultrasonography is effective at diagnosing a steer as negative, but the likelihood of detecting a negative is greater than detecting a positive because of the low prevalence of liver abscesses among the steers in each study. Even with modern ultrasound equipment with improved resolution, liver abscesses remain difficult to detect in live cattle, but sensitivity seems to be improved in lighter versus heavier weight cattle.

目的探讨超声在牛肝脓肿诊断中的应用价值。材料与方法试验1和试验2选用肥育阉牛（n = 160，平均末重649 kg）（n = 63，平均末重593 kg）。屠宰前24小时获得肝脓肿图像。试验3中的舵手(n = 40；平均最终体重= 168 kg)和4 (n = 40；平均最终体重= 159 kg)的牛×乳阉牛用于实验性肝脓肿的研究。在屠宰当天对肝脏进行实时超声成像。结果与讨论在实验1中，超声检查育肥牛肝脓肿的灵敏度为14.6%，在实验2中，超声检查肝脓肿的灵敏度为5.6%。在轻量级牛肉×乳牛中，试验2的敏感性为50%，试验3的敏感性为41.1%。在所有4个实验中，超声准确度在70%至75%之间。超声检查的特异性为84.6% ~ 100%。意义和应用所有实验的检测灵敏度都较低，表明超声在检测活牛肝脓肿方面的价值有限。尽管如此，观察到的更大的特异性表明超声检查在诊断阴性方面是有效的，但由于在每项研究中，肝脓肿的患病率较低，因此检测阴性的可能性大于检测阳性的可能性。即使使用分辨率提高的现代超声设备，肝脓肿仍然难以在活牛中检测到，但与体重较重的牛相比，体重较轻的牛的灵敏度似乎有所提高。

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引用次数: 0

Case Study: Assessment of greenhouse gas intensities on exemplary small and mid-sized US dairy farms 案例研究：美国中小型示范性奶牛场温室气体强度评估

IF 1.4 Q3 AGRICULTURE, DAIRY & ANIMAL SCIENCE

Applied Animal Science

Pub Date : 2025-02-01 DOI: 10.15232/aas.2024-02624

L.A. Olthof , K.R. Briggs , J.R. Knapp , B.J. Bradford

Objective

Our objective was to estimate greenhouse gas (GHG) intensities for 4 dairy farms representing the Northeast, Great Lakes, West, and Southeast US regions using the Farmers Assuring Responsible Management: Environmental Stewardship (FARM ES) life-cycle analysis model.

Materials and Methods

Four herds with <1,000 lactating cows, on farms selected as excellent environmental stewards, were assessed, with mean (±SD) production of 10,782 ± 2,037 kg/yr fat- and protein-corrected milk (FPCM). Data from 2021 were gathered from management software, interviews, and on-farm evaluations. Soil OM data for ≥7 yr were available on 3 farms. Emissions intensity was quantified as net CO₂ equivalents (CO₂e) emitted per unit of FPCM sold.

Results and Discussion

Mean (±SD) GHG emissions intensity was 0.97 ± 0.16 kg of CO₂e/kg of FPCM. In terms of point sources, FARM ES attributed 42 ± 6% of the farms’ emissions to enteric methane and 28 ± 9% to manure emissions. The remaining emissions were associated with feed production and energy use. Two farms that used manure separation had an average emissions intensity 0.20 kg of CO₂e/kg of FPCM less than farms that did not. Average annual soil carbon sequestration rates ranged from −0.82 to 3.52 Mg of carbon/ha, decreasing mean net GHG emissions intensity by 18% on these farms (0.81 vs. 0.99 kg of CO₂e/kg of FPCM).

Implications and Applications

Management practices have wide-ranging implications for dairy farm emissions intensities, and quantifying soil carbon sequestration is key for estimating net GHG emissions for a dairy farm.

我们的目标是使用农民保证负责任的管理：环境管理（FARM ES）生命周期分析模型来估计代表美国东北部、五大湖、西部和东南部地区的4个奶牛场的温室气体（GHG）强度。材料与方法选取环境管理优秀农场的4个奶牛群，共1000头泌乳奶牛，平均（±SD）产量为10,782±2,037 kg/年脂肪和蛋白质校正乳（FPCM）。2021年的数据从管理软件、访谈和农场评估中收集。3个农场有≥7年的土壤有机质数据。排放强度被量化为每单位销售的FPCM所排放的净二氧化碳当量（CO2e）。结果与讨论平均（±SD）温室气体排放强度为0.97±0.16 kg /kg FPCM。在点源方面，FARM ES将农场排放的42±6%归因于肠道甲烷，28±9%归因于粪便排放。其余的排放与饲料生产和能源使用有关。两个使用粪肥分离的农场的平均排放强度比没有使用粪肥分离的农场低0.20 kg CO2e/kg FPCM。年平均土壤固碳率为- 0.82至3.52毫克碳/公顷，这些农场的平均净温室气体排放强度降低了18%（0.81比0.99千克CO2e/千克FPCM）。影响和应用管理实践对奶牛场的排放强度有广泛的影响，量化土壤碳固存是估计奶牛场温室气体净排放量的关键。

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引用次数: 0

"February" Cover “二月”封面

IF 1.4 Q3 AGRICULTURE, DAIRY & ANIMAL SCIENCE

Applied Animal Science

Pub Date : 2025-02-01 DOI: 10.1016/S2590-2865(25)00005-9

引用次数: 0

Call for Submissions 征集意见书

IF 1.4 Q3 AGRICULTURE, DAIRY & ANIMAL SCIENCE

Applied Animal Science

Pub Date : 2025-02-01 DOI: 10.1016/S2590-2865(25)00010-2

引用次数: 0

Effects of initiating dietary narasin, at different production stages, on growth performance and carcass characteristics of growing-finishing pigs 不同生产阶段饲粮中添加纳拉西辛对生长肥育猪生长性能和胴体特性的影响

IF 1.4 Q3 AGRICULTURE, DAIRY & ANIMAL SCIENCE

Applied Animal Science

Pub Date : 2024-12-01 DOI: 10.15232/aas.2023-02515

Roger A. Arentson , Mark Knauer , Joe Gooding , Michael Shields , Scott N. Carr

Objective

Our objective was to determine the effects of initiating narasin, at different production stages, on growing-finishing pig performance.

Materials and Methods

In Exp. 1, 360 barrows (BW = 23.0 ± 0.13 kg) were used in a completely randomized design (45 pens; 15 replications) with 90-d treatments: (1) an unmedicated diet (CON), (2) 15 mg/kg narasin (NAR-90d), or (3) 11 mg/kg virginiamycin (VIR-90d). In Exp. 2, 480 barrows (BW = 26.3 ± 0.14 kg) were used in a completely randomized design (60 pens; 15 replications) with the following treatments: (1) unmedicated CON diet, (2) 15 mg/kg narasin (0 to 91 d; NAR-91d), (3) CON (0 to 56 d) followed by 15 mg/kg narasin fed from 56 to 91 d (NAR-35d), or (4) 27.6 mg/kg zinc bacitracin (0 to 91 d; ZB-91d). In Exp. 3, 416 barrows and gilts (BW = 84.3 ± 0.39 kg) were used in a randomized complete block design (52 pens; 26 replications) with 35-d treatments: (1) unmedicated CON diet or (2) NAR-35d.

Results and Discussion

In Exp. 1, pigs fed NAR-90d had greater BW (d 90) and ADG (d 0 to 90) compared with pigs fed the CON dietary treatment. The ADG of pigs fed NAR-90d were greater than those of pigs fed the CON treatment on d 0 to 28 and d 28 to 56 and VIR-90 on d 0 to 28. Pigs fed NAR-90d had greater hot carcass weights and yields than those fed CON or VIR-90d. In Exp. 2, pigs fed NAR-91d (d 0 to 56) and pigs fed NAR-35d (d 56 to 91) had greater ADG and ADFI than any of the other treatments. In Exp. 3, pigs fed NAR-35d had greater G:F than pigs fed the CON treatment.

Implications and Applications

Pigs fed narasin tended to have greater growth performance responses in the periods after first receiving narasin. However, when narasin is fed for the entire growing-finishing period, pigs may have carcass responses in some cases. Improvements in growth performance were realized whether narasin was initiated in the early grower or finishing phase.

我们的目的是确定在不同生产阶段启动纳拉西辛对生长肥育猪生产性能的影响。材料与方法在实验1中，采用完全随机设计(45只；15个重复)，90d处理：(1)无药饮食（CON）， (2) 15 mg/kg维吉尼霉素（NAR-90d），或(3)11 mg/kg维吉尼霉素（VIR-90d）。在实验2中，采用完全随机设计(60头；15个重复)，采用以下处理：(1)无药CON饮食，(2)纳拉西素15 mg/kg (0 ~ 91 d)；(3) CON (0 ~ 56 d)， 56 ~ 91d饲喂15 mg/kg纳拉辛（NAR-35d），或(4)27.6 mg/kg杆菌肽锌(0 ~ 91d；zb - 91 d)。在实验3中，416头母猪和后备母猪（体重= 84.3±0.39 kg）采用随机完全区组设计(52头；26个重复)，35d处理：(1)无药CON饮食或(2)NAR-35d。结果与讨论在试验1中，饲粮饲喂NAR-90d的猪的体重（90d）和平均日增重（0 ~ 90d）高于饲粮饲喂CON的猪。饲喂NAR-90d的猪在第0 ~ 28天和第28 ~ 56天和第0 ~ 28天的平均日增重均高于饲喂CON的猪。饲粮NAR-90d的猪热胴体重和产量高于饲粮CON和VIR-90d的猪。在试验2中，饲喂NAR-91d （0 ~ 56 d）和饲喂NAR-35d （56 ~ 91d）的猪ADG和ADFI均高于其他任何处理。在实验3中，饲喂NAR-35d的猪的G:F大于CON处理的猪。意义和应用饲喂纳拉西辛的猪在第一次接受纳拉西辛后的一段时间内往往有更大的生长性能反应。然而，如果在整个生长-肥育期都饲喂那拉西辛，在某些情况下猪可能会有胴体反应。无论在生长期早期还是育肥期开始使用纳拉西辛，生长性能都得到了改善。

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引用次数: 0

Perspectives and Commentary: Fat nutrition and metabolism of early-lactation dairy cows 展望与评论：泌乳早期奶牛的脂肪营养与代谢

IF 1.4 Q3 AGRICULTURE, DAIRY & ANIMAL SCIENCE

Applied Animal Science

Pub Date : 2024-12-01 DOI: 10.15232/aas.2024-02540

A.F. Kertz

Purpose

My objective was to review key factors involved in identifying and characterizing how dairy cows metabolize fat sources and their resultant effects on DMI, milk fat depression, and body condition, with emphasis on early lactation. Thus, short-term, mid-lactation studies were not included.

Sources

The main sources of information were peer-reviewed journal articles, some dairy nutrition conference proceedings, a monograph, several abstracts, a still pertinent periodical article (Lock and Bauman, 2007), and 50 yr of research and field experiences in this area.

Synthesis

Forms of fat, such as triglycerides or free fatty acids whether unsaturated or saturated, affect DMI, milk fat depression, and body condition. The more unsaturated that fatty acids (FA) are, especially the amount of linoleic acid, the more negatively these facets are affected.

Conclusions and Applications

Know what kinds of fat sources are being fed. What is the FA composition of feedstuffs fed and fat sources, especially the UFA and their levels? The more UFA sources there are, the more DMI and milk fat percentage may be negatively affected. Linoleic FA is a key marker for these negative effects, which may ensue if daily intake of linoleic acid is 300 to 400 g or more. This can be exacerbated by other factors such as low dietary forage levels, greater starch, wet forages, and finely chopped forages, which all contribute to lower rumen pH, which facilitates milk fat depression. Reduction in DMI is the major consideration when fat supplementation occurs, with digestibility of fat supplements being a secondary consideration. Either palmitic or stearic acid above 80%, but especially above 90%, in a fat supplement is of concern and may be less digestible because they can become more crystalline. This can also be a factor when physically blending these single sources together. However, if these 2 FA sources are melted and then prilled, this crystalline formation is not likely to occur. Palmitic and stearic acids melted together and then prilled incorporate the complementary benefits of both, potentially in ratios of 1:1 to 2:1, palmitic to stearic acid.

本研究的目的是回顾识别和描述奶牛代谢脂肪来源的关键因素，以及它们对DMI、乳脂抑制和身体状况的影响，重点是泌乳早期。因此，短期、中期泌乳研究未纳入。信息的主要来源是同行评议的期刊文章、一些乳制品营养会议记录、一本专著、几篇摘要、一篇仍然相关的期刊文章（Lock and Bauman, 2007），以及该领域50年的研究和实地经验。脂肪的合成形式，如甘油三酯或游离脂肪酸，无论是不饱和的还是不饱和的，都会影响DMI、乳脂抑制和身体状况。脂肪酸（FA）越不饱和，尤其是亚油酸的含量越高，这些方面受到的负面影响就越大。结论与应用了解饲料的脂肪来源，饲料中脂肪酸的组成和脂肪来源，特别是不饱和脂肪酸的含量及其水平。UFA来源越多，DMI和乳脂率可能受到的负面影响越大。亚油酸FA是这些负面影响的关键标志，如果每天摄入亚油酸300至400克或更多，这些负面影响可能会随之而来。其他因素如饲粮饲料水平低、淀粉含量高、湿饲料和切碎的饲料等也会加剧这种情况，这些因素都会降低瘤胃pH值，从而有助于降低乳脂。当脂肪补充发生时，DMI的减少是主要考虑因素，脂肪补充的消化率是次要考虑因素。棕榈酸或硬脂酸超过80%，特别是超过90%，在脂肪补充剂中是值得关注的，可能不易消化，因为它们会变得更结晶。在物理上将这些单一源混合在一起时，这也可能是一个因素。然而，如果这两种FA源被熔化，然后被碾压，这种晶体的形成就不太可能发生。棕榈酸和硬脂酸融化在一起，然后以1:1到2:1的比例，将两者的互补优势结合在一起。

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引用次数: 0

Economic returns and market risk of extending days on feed for beef × dairy cross heifers 延长肉牛和奶牛杂交母牛饲喂天数的经济回报和市场风险

IF 1.4 Q3 AGRICULTURE, DAIRY & ANIMAL SCIENCE

Applied Animal Science

Pub Date : 2024-12-01 DOI: 10.15232/aas.2024-02616

C.S. Schmaltz , T.C. Schroeder , L.J. Walter , J.P. Hutcheson

Objective

Our objective was to estimate economic net returns and return risk for beef × dairy cross heifers as days on feed (DOF) are extended.

Materials and Methods

Cattle production information and carcass performance data were obtained from a recent publication detailing a beef × dairy heifer cross serial slaughter study. Before final implant date heifers were treated the same through the first 265 DOF. At terminal implant, heifers were randomized into 4 treatment groups. Treatment 1 was fed for 58 d after randomization; treatment 2 for 79 d; treatment 3 for 97 d; and treatment 4 for 120 d. Baseline budgets were constructed using 5-yr average prices. Scenarios varying prices and costs and risk analysis of price changes over extended DOF were analyzed.

Results and Discussion

Net returns varied in economically important ways as DOF were extended. In baseline scenario, treatment 1 had highest net return of $99.84/head (hd) and treatment 4 lowest return of $57.13/ hd. Changing feed cost, carcass base price, and QG adjustments generally did not alter ordering of net returns across DOF. With low feed prices or high carcass prices, extending DOF increased net returns in some scenarios. Sensitivity analysis changing prices revealed base carcass price was the dominant risk determinant representing >90% of return risk. Return standard deviations ranged $69.06/hd for 3 wk extended DOF to $114.52/hd for 9 wk.

Implications and Applications

Extending DOF reduced net returns in the baseline. With different market conditions from baseline, extending DOF could increase returns. Market risk, especially carcass base price changes, was prevalent when extending DOF.

我们的目的是估计随着饲料日长（DOF）的延长，牛乳杂交小母牛的经济净收益和收益风险。材料与方法犊牛生产信息和胴体性能数据来源于近期发表的一篇牛乳小母牛杂交连续屠宰研究。在最终植入日之前，小母牛通过前265 DOF进行相同的处理。末端植入时，将母牛随机分为4个处理组。处理1随机分组后饲养58 d；处理2为79 d；处理3为97 d；治疗4为120 d。基线预算采用5年平均价格构建。分析了价格变化的情景和成本，并对价格变化的风险进行了分析。结果和讨论网的回报在经济上重要的方式随着自由度的扩大而变化。在基线情况下，治疗1的净收益最高，为99.84美元/头（hd），治疗4的净收益最低，为57.13美元/头。改变饲料成本，胴体基础价格和QG调整通常不会改变跨DOF的净回报顺序。在低饲料价格或高胴体价格的情况下，在某些情况下，延长DOF会增加净收益。价格变化的敏感性分析显示，基本胴体价格是主要的风险决定因素，代表了90%的回报风险。返回标准差范围为69.06美元/hd，为期3周，DOF延长至114.52美元/hd，为期9周。影响和应用扩展DOF降低了基线的净收益。在与基线不同的市场条件下，延长DOF可以增加收益。市场风险，特别是胴体基础价格的变化，在扩大DOF时是普遍存在的。

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引用次数: 0

Restricting bunk space allotments to 15 or 25 centimeters per head has minimal effects on growth performance in limit-fed growing beef heifers 将每头牛的铺位分配限制在 15 厘米或 25 厘米，对限饲生长肉用小母牛的生长性能影响甚微

IF 1.4 Q3 AGRICULTURE, DAIRY & ANIMAL SCIENCE

Applied Animal Science

Pub Date : 2024-12-01 DOI: 10.15232/aas.2024-02625

W. Cole Ellis, Zachary M. Duncan, Madeline S. Grant, William R. Hollenbeck, Evan C. Titgemeyer, Dale A. Blasi

Objective

Our objective was to evaluate the effects of bunk allotment on growth performance of receiving beef heifers limit fed a diet based on high-energy corn and corn co-products, in pens that contained 18 to 28 heifers.

Materials and Methods

Beef heifers (291 ± 15.5 kg; n = 332) were used in a randomized complete block design. Heifers were blocked by origin, stratified by indi- vidual arrival weight, and assigned to pen within block. Pens were randomly assigned to 1 of 4 treatments, with 4 pens per treatment, that provided 15.2, 25.4, 35.6, or 45.7 cm of linear bunk per heifer. Heifers were limit fed a high- energy diet once daily at 2.0% of BW (DM basis) for 56 d. Individual BW were measured on d 0 and 56. Pen BW were measured weekly and used to adjust feed delivered for the following week.

Results and Discussion

Bunk allotments of 15.2, 25.4, 35.6, or 45.7 cm per heifer did not affect final BW, ADG, DMI, or G:F. At feeding, 43%, 62%, 79%, and 96% of heifers in the pen had access to the feed bunk when allotted 15.2, 25.4, 35.6, and 45.7 cm of linear bunk per heifer, respectively. The SD of ADG within the pen did not differ among feed bunk sizes.

Implications and Applications

Bunk allotments as low as 15.2 to 25.4 cm per heifer can be used without negatively influencing growth performance of growing beef heifers of about 290 to 360 kg of BW that are limit fed a high-energy diet at 2.0% of BW (DM basis) once daily in pens that contained 18 to 28 head.

目标我们的目标是评估饲喂以高能玉米和玉米副产品为基础日粮的限位接收肉用小母牛的饲养栏（内有 18 到 28 头小母牛）中，铺位分配对其生长性能的影响。小母牛按产地分区，按到达体重分层，并分配到区块内的畜栏。围栏被随机分配到 4 种处理中的一种，每种处理有 4 个围栏，每头母牛的线性铺位分别为 15.2、25.4、35.6 或 45.7 厘米。小母牛每天限喂一次高能量日粮，喂量为体重的 2.0%（以 DM 为基础），持续 56 天。结果与讨论每头小母牛的体重分配为 15.2、25.4、35.6 或 45.7 cm 不会影响最终体重、ADG、DMI 或 G:F。饲喂时，当每头母牛分配到 15.2、25.4、35.6 和 45.7 厘米长的线性铺位时，栏内分别有 43%、62%、79% 和 96% 的母牛能接触到饲料铺位。对于体重约为 290 至 360 千克的生长中的肉用小母牛，可以使用低至每头 15.2 至 25.4 厘米的饲料铺，而不会对其生长性能产生负面影响，因为这些小母牛被限制饲喂高能量日粮，每天一次的饲喂量为体重的 2.0%（DM 基础值），饲养圈的数量为 18 至 28 头。

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引用次数: 0

Evaluation of extruded and expelled soybean meal as a partial replacement for dried distillers grains plus solubles in diets for finishing beef steers 膨化豆粕部分替代干酒糟和可溶物用于育肥肉牛饲粮的评价

IF 1.4 Q3 AGRICULTURE, DAIRY & ANIMAL SCIENCE

Applied Animal Science

Pub Date : 2024-12-01 DOI: 10.15232/aas.2024-02581

Zachary K. Smith, Becca B.G. Francis, Justin J. Delver, Forest L. Francis, Erin R. DeHaan, Thiago L.M. Ribeiro, Warren C. Rusche

Objective

This study evaluated the use of extruded and expelled soybean meal (EESBM) as a partial replacement (30% or 60% replacement; DM basis) of dried distillers grains plus solubles (DDGS) in diets offered to finishing beef steers.

Materials and Methods

Steers (n = 144 steers; 399 ± 28.9 kg) were used in a 150-d finishing trial. Steers were group housed in 18 pens (n = 8 steers/pen) and allocated to one of 3 dietary treatments in a randomized complete block design (n = 6 pens/treatment). Treatments included (1) finishing diet that included 15% DDGS (DM basis; CON); (2) finishing diet that included 30% replacement (DM basis) of DDGS with EESBM (EESBM30), and (3) finishing diet that included 60% replacement (DM basis) of DDGS with EESBM (EESBM60). Steers were fed twice daily and managed for maximum intake using a slick bunk management approach.

Results and Discussion

Dry matter intake increased linearly when EESBM replaced DDGS. Average daily gain and gain efficiency (both live-basis shrunk 4% and from carcass-adjusted final BW), as well as hot carcass weight, increased linearly with greater inclusion of EESBM. No other carcass trait outcomes, nor the distribution of USDA YG and QG, lung scores, or liver health outcomes were influenced by dietary treatment.

Implications and Applications

Using EESBM in replacement of DDGS results in greater intake, efficiency, and final body and carcass weight with no detriment to carcass yield or quality.

目的：本研究评估挤压和排出豆粕（EESBM）作为部分替代(30%或60%替代；以干酒糟和可溶性物（DDGS）为基础，添加到育肥牛饲粮中。研究对象（n = 144）；体重399±28.9 kg)，进行150 d的育肥试验。试验采用完全随机区组设计（n = 6个栏/处理），将18个栏（n = 8头/栏）分为3个饲粮处理中的一个。处理包括：(1)饲粮中添加15% DDGS (DM)；CON);(2)用EESBM30替代30% （DM基础）的DDGS，(3)用EESBM60替代60% （DM基础）的DDGS。每天喂食两次，并使用光滑的铺位管理方法进行最大摄入量管理。结果与讨论EESBM替代DDGS后干物质采食量呈线性增加。随着EESBM添加量的增加，平均日增重和增重效率（以活体为基础缩小4%，以胴体调整后的最终体重计算）以及热胴体重呈线性增加。其他胴体性状指标、USDA YG和QG的分布、肺评分或肝脏健康指标均不受饮食治疗的影响。使用EESBM替代DDGS可获得更高的采食量、效率、最终体重和胴体重，而不会损害胴体产量或质量。

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引用次数: 0

Evaluating the influence of heritable, metabolic, and production variables on the postpartum estrus expression of Holstein cows in a voluntary milking system 在自愿挤奶系统中评估遗传、代谢和生产变量对荷斯坦奶牛产后发情表达的影响

IF 1.4 Q3 AGRICULTURE, DAIRY & ANIMAL SCIENCE

Applied Animal Science

Pub Date : 2024-12-01 DOI: 10.15232/aas.2024-02603

S.G. Johnson, T.M. Marins, S. Tao, J.F. Bohlen

Objective

This observational study aimed to explore metabolic markers, nonesterified fatty acids (NEFA), glucose, insulin, and insulin resistance, alongside heritable fertility marker anti-Müllerian hormone (AMH), and their influence on postpartum estrus expression in a voluntary milking system (VMS).

Materials and Methods

Holstein cows (n = 95) were enrolled at 14 ± 3 DIM with blood samples taken weekly. All samples were analyzed for metabolic profiles of NEFA, glucose, and insulin until 49 ± 3 DIM. Insulin resistance was estimated at each time point using the Revised Quantitative Insulin Sensitivity Check Index (RQUICKI). Visits to the VMS and milk production data were collected on day of sampling and averaged with data from the preceding day and following day. Cows were fitted with DeLaval AM2 collars and monitored from calving until 100 DIM using DelPro Farm Manager. Both (++) (activity 5 SD above normal activity levels) and (+++) (activity 6 SD above normal activity levels) reproductive attentions in DelPro were used to identify an estrus event, with estrus intensity recorded. Cows were grouped by time to resumption of estrus expression, with the normal group (NG) having an estrus event on or before 45 DIM and the delayed group (DG) resuming beyond 45 DIM. Data were analyzed using the CORR and MIXED procedure of SAS.

Results and Discussion

Greater milk yield corresponded with increased VMS visits (r = 0.39). Blood glucose concentrations were greater for NG cows on d 35 and 42. Serum NEFA concentrations decreased in all animals over time. Insulin increased over time in all cows but did not differ between NG and DG cows. The RQUICKI did not change over time for either NG or DG cows. Estrus intensity was not different in NG (191% ± 6.6%) versus DG cows (179.1% ± 5.97%), and AMH was not different between NG (223.4 ± 28.62 pg/mL) and DG cows (217.6 ± 25.22 pg/mL).

Implications and Applications

Milk production and its association with glucose and VMS visits are key drivers for postpartum estrus expression of cows in a VMS.

目的本观察性研究旨在探讨代谢标志物、非酯化脂肪酸（NEFA）、葡萄糖、胰岛素和胰岛素抵抗，以及遗传性生育标志物抗勒氏激素（AMH），以及它们对自愿挤奶系统（VMS）产后发情表达的影响。材料与方法选取14±3岁的肖尔斯坦奶牛95头，每周采血一次。在49±3 DIM前分析所有样本的NEFA、葡萄糖和胰岛素代谢谱。使用修订的定量胰岛素敏感性检查指数（RQUICKI）估计每个时间点的胰岛素抵抗。在采样当天收集对VMS的访问和产奶量数据，并与前一天和第二天的数据进行平均。奶牛安装DeLaval AM2项圈，并使用DelPro Farm Manager从产犊到100 DIM进行监测。用DelPro的（++）（活动高于正常活动水平5 SD）和（+++）（活动高于正常活动水平6 SD）生殖关注来识别发情事件，并记录发情强度。按照奶牛恢复发情表达的时间进行分组，正常组（NG）在45 DIM时或之前发情，延迟组（DG）在45 DIM后恢复发情。采用SAS的CORR和MIXED程序分析数据。结果与讨论产奶量越大，VMS访问次数越多（r = 0.39）。NG奶牛在第35天和第42天血糖浓度较高。随着时间的推移，所有动物的血清NEFA浓度都有所下降。随着时间的推移，所有奶牛的胰岛素都有所增加，但在NG和DG奶牛之间没有差异。不管是NG牛还是DG牛，RQUICKI都没有随时间变化。NG奶牛的发情强度（191%±6.6%）与DG奶牛（179.1%±5.97%）无显著差异，AMH（223.4±28.62 pg/mL）与DG奶牛（217.6±25.22 pg/mL）无显著差异。意义和应用产奶量及其与葡萄糖和VMS访问的关联是VMS中奶牛产后发情表达的关键驱动因素。

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