丙酸钙对泌乳早期奶牛泌乳性能和代谢产物的影响

选用32头经产奶牛,根据泌乳期、上个泌乳期305 d产奶量和预产期,采用随机区组设计分为4组,对照组饲喂基础日粮,处理1、2、3组分别在基础日粮基础上添加丙酸钙100、200、300 g/d.结果显示,日粮添加丙酸钙对奶牛的采食量、乳脂率、乳蛋白率、乳糖率和乳干物质率无显著影响,200、300 g/d组产奶量和饲料转化效率显著高于对照组(P<0.05).200、300 g/d组血浆葡萄糖和胰岛素浓度显著高于对照组(P<0.05),而血浆游离脂肪酸和β-羟丁酸浓度显著低于对照组(P<0.05);200、300 g/d组尿酮浓度显著低于对照组和100 g/d组(P<0.05).试验结果表明,丙酸钙适宜添加量为200 g/d.     

丙酸镁对泌乳早期奶牛体况、泌乳性能和代谢参数的影响

选用36头经产奶牛,根据泌乳期、上一泌乳期305 d产奶量和预产期,采用随机区组设计分为4组,对照组饲喂基础日粮,处理1,2和3组分别在基础日粮基础上添加丙酸镁50,100和150 g/d,研究丙酸镁对泌乳早期奶牛采食量、泌乳性能、血液代谢参数和尿酮浓度的影响。结果表明,添加丙酸镁对奶牛的采食量、乳脂率、乳蛋白率、乳糖率和乳干物质率无显著影响,添加丙酸镁100和150 g/d对产乳量、饲料转化效率、体况及代谢参数有改善,该二处理组产奶量、饲料转化效率、体况评分、能量平衡、血浆葡萄糖和胰岛素浓度均显著高于对照组(P<0.05),而血浆游离脂肪酸和β-羟丁酸浓度显著低于对照组(P<0.05),尿酮浓度(除100 g/d组产后7 d测定值与50 g/d组无显著差异外)显著低于对照组和50 g/d组(P<0.05)。根据试验结果,丙酸镁适宜添加量为100 g/d。     

丙酸钙对泌乳早期奶牛体况和能量平衡的影响

选用32头经产奶牛,根据泌乳期、上一泌乳期305 d产奶量和预产期,采用随机区组设计分为4组,研究丙酸钙(0、100、200 g/d和300 g/d)时泌乳早期奶牛体况评分、体重变化和能量平衡的影响.结果表明:日粮添加丙酸钙对奶牛体况评分无显著影响,添加丙酸钙200 g/d和300 g/d显著改善了泌乳早期奶牛能量负平衡.减少了体重的下降.总之,添加丙酸钙明显改善了泌乳早期奶牛能量平衡,丙酸钙适宜添加量为200 g/d.     

脂肪酸钙对中国荷斯坦牛营养物质全消化道消化率影响的研究

选择6头经产、胎次相同、产后10～20d的中国荷斯坦奶牛，采用3×3重复拉丁方设计，研究脂肪酸钙对中国荷斯坦奶牛泌乳早期营养物质全消化道消化率的影响。试验处理分别为处理A组为基础日粮；处理B组为基础日粮+200g脂肪酸钙；处理C组为基础日粮+400g脂肪酸钙。试验结果表明日粮中添加脂肪酸钙对干物质、粗蛋白、酸性洗涤纤雏、中性洗涤纤维的全消化道消化率没有影响(p＞0.05)；使脂肪消化率升高(p＜0.05)，且脂肪消化率与脂肪酸钙的添加量呈线性正相关，相关系数为0.87。     

Combinations of cactus pear with different roughage sources on the production,chemical composition,and milk fatty acid profile of F1 Holstein/Zebu cows

Tropical Animal Health and Production - The qualities of food, mainly of animal origin, have always been of concern to consumers. It is known that the composition of animals’ diets can...     

Carbon kinetics of milk formation in Holstein cows in late lactation

Carbon transfer to milk in Holstein cows in late lactation was measured by introducing changes in the natural stable carbon isotope composition of the feed. Six Holstein cows in mid-lactation were placed on a diet naturally low in 13C (-25.0% vs Pee Dee belemnite [PDB] an international carbon isotope standard), based on alfalfa-barley, and six others were placed on a diet naturally enriched in 13C (-11.5% vs PDB), based on corn. After a 7-wk equilibration period on these diets, three cows were switched from alfalfa-barley to corn, and three were switched from corn to alfalfa-barley. The three other cows in each group served as controls. 13C/12C ratios were measured in daily morning milk samples during the week before and for 6 wk after the changes in diet. After the diets had been switched, milk isotope ratios rapidly approached the isotopic composition of the new diet, indicating rapid transfer of dietary carbon into milk. The data were consistent with a model whereby milk was synthesized from a single precursor pool that responded rapidly to dietary perturbation. The milk precursor pool had a half-life of approximately .9 d and had a mass of approximately 7 kg of carbon, which was renewed daily by the entry of 5 kg of digestible dietary carbon.     

Relationships of first lactation yields with lifetime performance traits in Holstein cows

SUMMARY: Genetic and phenotypic correlations between the first lactation and lifetime yields of milk, fat and protein, herdlife, productive life and number of lactations initiated in the herd were estimated from records of 24,231 progeny of 234 young and 119 proven Holstein sires in 1791 herds using a multivariate REML technique to fit a sire model with relationships among young sires. Proven sires were fitted as fixed effects. Genetic correlations between first lactation and lifetime yields were highest for milk (0.666) followed by fat (0.660) and protein (0.512). Genetic as well as phenotypic correlations of herdlife, productive life and number of lactations were higher with first lactation milk yield than with first lactation fat and protein yields. Direct selection for higher lifetime yields would not be effective because of low heritabilities. However the high, positive genetic correlations of lifetime yields of milk and fat with first lactation yields suggested that first lactation yields might be used for indirect selection for higher lifetime yields. ZUSAMMENFASSUNG: Beziehung zwischen Erstlaktations- und Lebensleistung bei Holstein-Kühen Zwischen Erstlaktations- und Lebensleistung für Milch, Fett, Protein, Verbleibedauer, produktiver Lebensdauer und Zahl von Laktationen in der Herde wurden von 24.291 T?chtern, 234 Jung- und 119 geprüften Holsteintieren in 1.791 Herden genetische Beziehungen gesch?tzt, wobei eine multivariate REML-Technik zur Analyse eines Stiermodells mit Verwandtschaft zwischen jungen Stieren angewendet worden ist. Die geprüften Stiere wurden als fixe Effekte angesehen. Genetische Korrelationen zwischen Erstlaktation und Lebensleistung war am h?chsten für Milch (0,666), gefolgt von Fett (0,660) und Protein (0,512). Genetische und ph?notypische Korrelationen mit Verbleibedauer, produktiver Lebensdauer und Zahl der Laktationen waren ebenfalls für Erstlaktations-milchmenge h?her als bei Fett und Protein. Direkte Selektion auf h?here Lebensleistung würde wegen der niedrigen Heritabilit?t nicht wirksam sein. Allerdings k?nnten die hohen positiven genetischen Korrelationen des Merkmals mit Erstlaktationsleistungen diese als geeignetes indirektes Selektionskriterium für h?here Lebensleistung anzeigen.     

Relationship between the lactation curve and udder disease incidence in different lactation stages in first‐lactation Holstein cows

We examined the relationships between the shape of the first parity lactation curve and udder disease incidence at different stages of lactation in 538 Holstein cows. Data used were first‐parity daily milk yields and treatment records. Each cow was classified according to whether or not it had had udder disease at least once over the whole lactation period or in one of three stages within the lactation period. We then examined the differences in the shapes of the lactation curves between the disease incidence and non‐incidence group in each stage. Cows that had high rates of increase in milk yield and high milk yields in early lactation were predisposed to udder disease afterwards. Cows with high milk production over a long period but with low lactation persistency were predisposed to udder disease after the peak of lactation. There was no difference in total milk yield between incidence and non‐incidence groups in all stages, suggesting that, for a comparable level of lactation, cows without udder diseases have flatter lactation curves.     

Genome-wide association for milk production and lactation curve parameters in Holstein dairy cows

The aim of this study was to identify genomic regions associated with 305-day milk yield and lactation curve parameters on primiparous (n = 9,910) and multiparous (n = 11,158) Holstein cows. The SNP solutions were estimated using a weighted single-step genomic BLUP approach and imputed high-density panel (777k) genotypes. The proportion of genetic variance explained by windows of 50 consecutive SNP (with an average of 165 Kb) was calculated, and regions that accounted for more than 0.50% of the variance were used to search for candidate genes. Estimated heritabilities were 0.37, 0.34, 0.17, 0.12, 0.30 and 0.19, respectively, for 305-day milk yield, peak yield, peak time, ramp, scale and decay for primiparous cows. Genetic correlations of 305-day milk yield with peak yield, peak time, ramp, scale and decay in primiparous cows were 0.99, 0.63, 0.20, 0.97 and −0.52, respectively. The results identified three windows on BTA14 associated with 305-day milk yield and the parameters of lactation curve in primi- and multiparous cows. Previously proposed candidate genes for milk yield supported by this work include GRINA, CYHR1, FOXH1, TONSL, PPP1R16A, ARHGAP39, MAF1, OPLAH and MROH1, whereas newly identified candidate genes are MIR2308, ZNF7, ZNF34, SLURP1, MAFA and KIFC2 (BTA14). The protein lipidation biological process term, which plays a key role in controlling protein localization and function, was identified as the most important term enriched by the identified genes.     

Dietary roughage sources affect lactating Holstein x Zebu cows under experimental conditions in Brazil: a meta-analysis

Tropical Animal Health and Production - To reduce costs, lactating cows are often fed a higher proportion of roughage and alternative feeds; however, such protocols may not lead to optimal milk...     

Response of dairy cows to protein level in early lactation

The comparison of cows' protein requirements with the supply of microbial and feed proteins digestible in the intestine shows a large deficit for the first weeks just after calving. The magnitude and duration of the deficit is reflected in the blood parameters of the protein status (protein, urea and free amino acid contents and composition) and of the energy status (glucose, free fatty acid content). Great increases in milk production are noted in this period by meeting protein requirements at all times during the first eight weeks after calving. Sometimes they are achieved at the expense of body stores, but in other cases they can be related to an increase in the efficiency of microbial digestion in the rumen, in the ingestibility of the feeds, or in the intake capacity of the cows. The effects on milk protein synthesis and on the intake capacity of the cows seem to be due to the supply of some essential amino acids, particularly methionine, but also to the supply of non-essential glucose precursor amino acids. More studies are needed on the mechanisms involved, on the long-term effects, and on the secondary effects on reproduction and health.     

Effects of malic acid on feed intake, milk yield, milk components and metabolites in early lactation Holstein dairy cows

The objective of this study was to evaluate the effects of malic acid (MA) on feed intake, milk yield and composition, blood metabolites and energy balance in early lactation Holstein dairy cows from 1 to 63 day in milk (DIM). Twenty-eight multiparous Holstein dairy cows, blocked by lactation number, previous 305-d mature equivalent milk production, and expected calving date, were arranged into four groups in a randomized block design. Treatments were: control (without MA), LMA, MMA and HMA with 70, 140 and 210 g malic acid per cow per day, respectively. The supplement of food grade MA (99.8% of MA) was hand-mixed into the top one-third of the daily ration. Cows were fed ad libitum a total mixed ration consisting of equal proportion of forage and concentrate. Milk yield increased (P = 0.04), but feed intake and milk components were not affected (P > 0.05) by MA supplementation. The energy balance, expressed as the difference between energy input and output, tended to be higher (P = 0.08) for MA supplemented cows during the 63-DIM period MA and supplemented cows showed a trend (P = 0.07) toward less loss of BW during the 63-day period, especially during the first 21-day of lactation. Concentrations of plasma glucose and serum insulin were higher for cows fed LMA, MMA, and HMA relative to control and linearly (P < 0.01) increased with increasing MA supplementation. Concentrations of non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA) and urine ketones were lower for MA-supplemented cows at 7, 14 and 21 DIM of lactation and linearly (P < 0.01) decreased with increasing MA supplementation. Although feed intake was not affected, milk yield increased, MA-supplemented cows experienced higher concentrations of plasma glucose and serum insulin, lower concentrations of plasma BHBA and NEFA, and lower concentrations of urine ketones, suggesting that nutrient digestibilities and energy availability may have been improved.     

Genetic relationships among female fertility disorders,female fertility traits and productivity of Holstein dairy cows in the early lactation period

Fertility health disorders from the early lactation period including retained placenta (REPLA), metritis (MET), corpus luteum persistence (CLP), anoestria/acyclia (AOEAC) and ovarial cysts (OC), as well as overall disease categories (disorders during the postpartal period (DPP), ovary infertility (OINF), overall trait definition “fertility disorders” (FD)), were used to estimate genetic (co)variance components with female fertility and test‐day traits. The disease data set comprised 25,142 Holstein cows from parities 1, 2 and 3 resulting in 43,584 lactations. For disease traits, we used the binary trait definition (sick or healthy) and disease count data reflecting the sum of treatments for the same disease within lactation or within lactation periods. Statistical modelling included single and multiple trait repeatability animal models for all trait combinations within a Bayesian framework. Heritabilities for binary disease traits ranged from 0.04 (OC) to 0.10 (REPLA) and were slightly lower for the corresponding sum trait definitions. Correlations between both trait definitions were almost one, for genetic as well as for permanent environmental effects. Moderate to high genetic correlations were found among puerperal disorders DPP, REPLA and MET (0.45–0.98) and among the ovarian disorders OINF, AOEAC, CLP and OC (0.59–0.99). Genetic correlations between puerperal and ovarian disorders were close to zero, apart from the REPLA–OC association (0.55). With regard to fertility disorders and productivity in early lactation, a pronounced genetic antagonistic relationship was only identified between OC and protein yield. Genetic correlations between fertility disorders and test‐day SCS were close to zero. OINF and all diseases contributing to OINF were strongly correlated with the female fertility traits “interval from calving to first service,” “interval from service to pregnancy” and “interval from calving to pregnancy.” The strong correlations imply that fertility disorders could be included in genetic evaluations of economic fertility traits as correlated predictors. Vice versa, a breeding focus on female fertility traits will reduce genetic susceptibility to OC, CLP and AOEAC.     

Effect of preventive intrauterine ozone application on reproductive efficiency in Holstein cows

The aim of the research was to determine the influence of preventive application of two different ozone preparations on reproductive efficiency in dairy cows with physiological puerperium. The research was conducted on 404 Holstein cows aged 2–8 years, divided into three groups. The first group consisted of cows treated using 6 intrauterine ozone pearls (RIPROMED OVULI O₃^®, Novagen, Italy) at once. The second group consisted of cows treated with ozone foam spray (RIGER SPRAY^®, Novagen, Italy) application in the body of uterus for 5 s, and the third group was the control group. Cows from the first two groups were observed and treated during early puerperium, 24–48 h after parturition. To assess the reproductive performance of Holstein cows, interval from calving to first insemination (days open to first service, DOFS), interval from calving to pregnancy (days open to pregnancy, DOP), relative pregnancy rate (%), first service conception rate (FSCR, %) and all service conception rate (ASCR, %) were measured. The estimate of hazard ratio (HR) for group B relative to group C for DOFS was 0.62 (p = 0.0002), implying that the relative rate of first service decreased in the control group by 38%. The estimate of HR for group B relative to group C for DOP was 0.65 (p = 0.0006), implying that the relative rate of pregnancy decreased in group C by 35%. Cows treated with Riger spray (group B) became pregnant earlier and had better FSCR and ASCR. It is supposed that the form of ozone preparations and the amount of active substance were decisive. A conclusion may be made that preventive ozone intrauterine application during early puerperal period, especially the foaming form of ozone preparations (spray), improved the reproductive efficacy in dairy cows.     

复方中草药添加剂对荷斯坦奶牛免疫和泌乳性能的影响

试验旨在研究自制的复方中草药添加剂对泌乳奶牛免疫机能与泌乳性能的影响。试验采用4×4拉丁方设计。选择4头胎次、泌乳天数、体重均相近的健康荷斯坦奶牛,分为4组,其中A组为对照组,饲喂基础饲粮,B、C、D组分别在基础饲粮中添加30、50和80 g/d复方中草药。试验分4期进行,每期28 d(预试期7 d,正试期14 d,排空期7 d)。结果显示:1)添加复方中草药显著增加了白细胞数、嗜中性细胞百分比及血小板数(P<0.05);但对血液生化指标无显著影响(P>0.05)。2)添加复方中草药显著降低了丙二醛(MDA)含量(P<0.05);与对照组相比,添加30 g/d复方中草药显著增加了血清免疫球蛋白M(IgM)及超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)活力(P<0.05)。3)复方中草药添加剂可以增加血清生长激素(GH)和催乳素(PRL)含量,且添加30 g/d时显著增加(P<0.05)。4)与对照组相比,日粮添加30、50和80 g/d可以使产奶量分别增加10.18%、6.79%和5.19%,但是对产奶量、乳成分及体细胞数的影响均不显著(P>0.05)。试验结果表明,复方中草药添加剂可以调节奶牛机体免疫性能和提高抗氧化能力,且每头牛添加30 g/d时效果最佳。但其对奶牛泌乳性能无显著影响。     

Effect of lactation stage, season and parity on milk cortisol concentration in Holstein cows

This experiment was designed (1) to study the effects of lactation stage, season, and parity on milk cortisol concentrations in Holstein cows, and (2) to elucidate the relationships between milk yield, quality, and milk cortisol concentration. Subjects of this study were 24 dairy cows kept in a free stall barn. Milk samples were taken on test day in May, August, November, and February. Data of milk yield, quality, and cortisol concentration were collected. Random effects of animals and fixed effects of lactation stage, test day, and parity on milk yield, quality, and cortisol concentration were analyzed using mixed models. We estimated the best linear unbiased prediction of each trait (BLUP) which was an animal-specific value. Correlation among milk yield, quality, and cortisol concentration was calculated using raw data and BLUP. The effect of the lactation stage on milk cortisol concentration was significant: the value observed in early lactation was higher than in other stages. However, the correlation between milk yield and cortisol concentration was low. The beginning of lactation might be a strong stressor for every cow. Calculated with raw data, milk cortisol concentration had respectively significant negative correlation with milk protein contents and solid not-fat contents. Calculated with BLUP, milk cortisol concentration showed a significant and negative correlation with milk protein contents. The lactation stage and milk protein contents should be considered for measurement of milk cortisol concentrations.     

基于转录组测序的奶牛泌乳初期与干奶期肝脏差异表达基因分析

旨在通过对奶牛干奶期和泌乳初期肝脏组织进行转录组测序和生物信息学分析,探明其不同生理阶段的差异表达基因和差异代谢通路。选取305 d产奶量接近、干奶天数一致、怀孕天数接近的中国荷斯坦奶牛3头,分别在干奶期(产前50 d)和泌乳初期(产后15 d)活体采集肝脏组织,利用Illumina Hiseq~(TM)2500高通量RNA-seq测序技术对干奶期和泌乳初期肝脏RNA测序,使用TopHat2软件将测序得到的reads序列与牛(UMD3.1.66)参考基因组序列比对,在GO和KEGG数据库中进行聚类分析和富集分析。结果显示,泌乳初期和干奶期肝脏中差异表达基因共有409个,与干奶期相比,泌乳初期表达上调的基因有235个,下调的基因有174个。GO功能分类注释到生物学过程、细胞组成和分子功能数据库中的GO条目分别有63,41,15条。注释到KEGG的显著富集通路有21条(P0.05)。该研究结果为挖掘奶牛产奶性状的候选基因提供了技术依据。     

Changes in various metabolic parameters in blood and milk during experimental Escherichia coli mastitis for primiparous Holstein dairy cows during early lactation

Background:The objective of this study was to characterize the changes in various metabolic parameters in blood and milk during IMI challenge with Escherichia coli(E.coli) for dairy cows during early lactation.Thirty,healthy primiparous Holstein cows were infused(h = 0) with-20-40 cfu of live ? coli into one front mammary quarter at ~4-6wk in lactation.Daily feed intake and milk yield were recorded.At-12,0,3,6,12,18,24,36,48,60,72,96,108,120,132,144,156,168,180 and 192 h relative to challenge rectal temperatures were recorded and quarter foremilk was collected for analysis of shedding of E.coli.Composite milk samples were collected at-180,-132,-84,-36,-12,12,24,36,48,60,72,84,96,132 and 180 h relative to challenge(h = 0) and analyzed for lactate dehydrogenase(LDH),somatic cell count,fat,protein,lactose,citrate,beta-hydroxybutyrate(BHBA),free glucose(fglu),and glucose-6-phosphate(G6P).Blood was collected at-12,0,3,6,12,18,24,36,60,72,84,132 and 180 h relative to challenge and analyzed for plasma non-esterified fatty acids(NEFA),BHBA and glucose concentration.A generalized linear mixed model was used to determine the effect of IMI challenge on metabolic responses of cows during early lactation.Results:By 12 h,E.coli was recovered from challenged quarters and shedding continued through 72 h.Rectal temperature peaked by 12 h post-challenge and returned to pre-challenge values by 36 h post-IMI challenge.Daily feed intake and milk yield decreased(P 0.05) by 1 and 2 d,respectively,after mastitis challenge.Plasma BHBA decreased(12 h;P 0.05) from 0.96 ± 1.1 at 0 h to 0.57 ±0.64 mmol/L by 18 h whereas concentration of plasma NEFA(18 h) and glucose(24 h) were significantly greater,11 and 27%,respectively,after challenge.In milk,fglu,lactose,citrate,fat and protein yield were lower whereas yield of BHBA and G6 P were higher after challenge when compared to pre-challenge values.Conclusions:Changes in metabolites in blood and milk were most likely associated with drops in feed intake and milk yield.However,the early rise in plasma NEFA may also signify enhanced adipose tissue lipolysis.Lower concentrations of plasma BHBA may be attributed to an increase transfer into milk after IMI.Decreases in both milk lactose yield and%after challenge may be partly attributed to reduced conversion of fglu to lactose.Rises in G6 P yield and concentration in milk after challenge(24 h) may signify increased conversion of fglu to G6 P.Results identify changes in various metabolic parameters in blood and milk after IMI challenge with E.coli in dairy cows that may partly explain the partitioning of nutrients and changes in milk components after IMI for cows during early lactation.     

Changes in various metabolic parameters in blood and milk during experimental Escherichia coli mastitis for primiparous Holstein dairy cows during early lactation

Background

The objective of this study was to characterize the changes in various metabolic parameters in blood and milk during IMI challenge with Escherichia coli (E. coli) for dairy cows during early lactation. Thirty, healthy primiparous Holstein cows were infused (h = 0) with ~20-40 cfu of live E. coli into one front mammary quarter at ~4-6 wk in lactation. Daily feed intake and milk yield were recorded. At –12, 0, 3, 6, 12, 18, 24, 36, 48, 60, 72, 96, 108, 120, 132, 144, 156, 168, 180 and 192 h relative to challenge rectal temperatures were recorded and quarter foremilk was collected for analysis of shedding of E. coli. Composite milk samples were collected at -180, -132, -84, -36, -12, 12, 24, 36, 48, 60, 72, 84, 96, 132 and 180 h relative to challenge (h = 0) and analyzed for lactate dehydrogenase (LDH), somatic cell count, fat, protein, lactose, citrate, beta-hydroxybutyrate (BHBA), free glucose (fglu), and glucose-6-phosphate (G6P). Blood was collected at -12, 0, 3, 6, 12, 18, 24, 36, 60, 72, 84, 132 and 180 h relative to challenge and analyzed for plasma non-esterified fatty acids (NEFA), BHBA and glucose concentration. A generalized linear mixed model was used to determine the effect of IMI challenge on metabolic responses of cows during early lactation.

Results

By 12 h, E. coli was recovered from challenged quarters and shedding continued through 72 h. Rectal temperature peaked by 12 h post-challenge and returned to pre-challenge values by 36 h post-IMI challenge. Daily feed intake and milk yield decreased (P <0.05) by 1 and 2 d, respectively, after mastitis challenge. Plasma BHBA decreased (12 h; P <0.05) from 0.96 ± 1.1 at 0 h to 0.57 ± 0.64 mmol/L by 18 h whereas concentration of plasma NEFA (18 h) and glucose (24 h) were significantly greater, 11 and 27%, respectively, after challenge. In milk, fglu, lactose, citrate, fat and protein yield were lower whereas yield of BHBA and G6P were higher after challenge when compared to pre-challenge values.

Conclusions

Changes in metabolites in blood and milk were most likely associated with drops in feed intake and milk yield. However, the early rise in plasma NEFA may also signify enhanced adipose tissue lipolysis. Lower concentrations of plasma BHBA may be attributed to an increase transfer into milk after IMI. Decreases in both milk lactose yield and % after challenge may be partly attributed to reduced conversion of fglu to lactose. Rises in G6P yield and concentration in milk after challenge (24 h) may signify increased conversion of fglu to G6P. Results identify changes in various metabolic parameters in blood and milk after IMI challenge with E. coli in dairy cows that may partly explain the partitioning of nutrients and changes in milk components after IMI for cows during early lactation.