186 Young Scholar Presentation: Immunometabolism during periods of negative nutrient balance or heat stress is altered by dietary methyl donor supply in dairy cows

Abstract Our research examined the effects of enhancing methyl donor supply on immunometabolism during periods of negative nutrient balance (NNB) or heat stress (HS). The first experiment examined the effects of post-ruminal choline supply during NNB on production and pathways of 1-carbon metabolism. Ten primiparous rumen-cannulated cows (158±24 DIM) were used in a replicated 5×5 Latin square design with 4d treatment periods and 10d of recovery. Treatments were unrestricted intake with abomasal infusion of water, restricted intake (R; 60% of net energy for lactation requirements) with abomasal infusion of water or R plus abomasal infusion of 6.25, 12.5, or 25 g/d choline ion. Liver tissue was collected at the end of each treatment period. Enhancing choline supply increased milk yields, but decreased liver triacylglycerol. Activity of betaine homocysteine methyltransferase increased with choline, while methionine synthase tended to increase, and cystathionine β-synthase was decreased. These changes were associated with increased liver and plasma Met. Overall, enhanced supply of choline during NNB increases flux through the Met cycle to regenerate Met and reduce liver triacylglycerol. The second experiment examined the effects of rumen-protected Met (RPM) during HS on mTOR (mechanistic target of rapamycin)-related signaling proteins in the mammary gland. Thirty-two multiparous cows (184±59 DIM) were assigned to an environmental treatment, and a dietary treatment [TMR with RPM (0.105% DM) or without (CON)] in a crossover design. There were 2 periods with 2 phases per period. In phase 1 (9d), all cows were in thermoneutral conditions (TN) and fed ad libitum. During phase 2 (9d), group 1 (n=16) was exposed to HS using electric heat blankets while group 2 (n=16) remained in TN but were pair-fed to HS counterparts. After a washout period (21d), the study was repeated (period 2), with environmental treatments being inverted and dietary treatments remaining the same. Mammary tissue was collected at the end of phase 2. Abundance of phosphorylated mTOR was greater with RPM and tended to be greater with HS. Control cows had a greater decrease in milk protein (%) during phase 2 (difference from phase 1) compared with RPM cows, suggesting that RPM supplementation during HS may support greater milk protein synthesis via mTOR activation. The third experiment investigated the effects of RPM during HS on the response of mammary gland explants to lipopolysaccharide (LPS). Twenty-five mg of tissue obtained from cows in the second experiment was incubated with 0 or 3 μg/mL of LPS for 2h. Incubation with LPS increased abundance of genes associated with inflammation, while HS decreased genes associated with antioxidant responses. Expression of NFKB1was greater in LPS-treated explants from non-HS compared with HS cows. These data indicate that HS reduced immune and antioxidant responses while RPM did not attenuate the inflammatory response induced by LPS in vitro. Overall, data indicated a beneficial effect of choline during NNB and Met during HS on immunometabolism in dairy cows.

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The role of the mammary gland during heat stress

10.32469/10355/72201 ◽

2019 ◽

Author(s):

◽

Ricardo Oliveira Rodrigues

Keyword(s):

Blood Flow ◽

Heat Stress ◽

Mammary Gland ◽

Dairy Cows ◽

Prolonged Exposure ◽

Transcriptional Profiling ◽

Mammary Tissue ◽

Secretory Cells ◽

University Of Missouri ◽

Lactating Dairy Cows

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Disruptive effects of climate change, such as increasing environmental temperature, have direct impacts on economic viability and efficiency of food production. In lactating dairy cows, heat stress reduces milk production and alters function of mammary secretory cells, at least partly by disturbing local protein metabolism. We hypothesized that hyperthermia would not only reduce mammary blood flow but would also reduce mammary extraction of nutrients from blood. In addition, we hypothesized that transcriptional profiling of mammary tissue would reveal disruption of cellular homeostasis. Our objective was to determine the effects of hyperthermia on mammary function. More specifically, we aimed to profile mammary blood flow and the changes in mammary transcriptome of heat-stressed lactating dairy cows. We investigated the effects of early and prolonged exposure of lactating dairy cows to hyperthermia by exposing cows to programmed constantly elevated temperature and humidity to induce and maintain body temperature approximately 1[degree]C above normal. Experiments were conducted to evaluate the production responses of hyperthermic lactating dairy cows, to characterize total and nutritive mammary blood flow, and to elucidate the regulation of mammary function during early and prolonged exposure to hyperthermia. Results from these studies established that 1) hyperthermia reduces total and nutritive mammary blood flow, limiting nutrient disappearance across the mammary gland; 2) hyperthermia does not induce shunting of blood away from the gland; 3) hyperthermia affects mammary tissue transcriptome, mainly altering processes associated with ECM and cell adhesion; 4) the effects of exposure to prolonged heat stress on mammary gene expression are distinct from the effects of feed restriction, in lactating dairy cows; and 5) mammary function is reestablished within 8 days after cessation of heat stress.

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Peptide utilisation by the mammary gland of lactating goats.

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600025794 ◽

1994 ◽

Vol 1994 ◽

pp. 26-26

Author(s):

F.R.C. Backwellf ◽

B J. Bequettet ◽

J.A. Metcalf ◽

D. Wray-Cahen ◽

L. Crompton ◽

...

Keyword(s):

Mammary Gland ◽

Dairy Cows ◽

Milk Protein ◽

Dairy Goats ◽

Small Peptides ◽

Lactating Goats ◽

Uptake Studies ◽

Milk Casein ◽

Casein Synthesis

During lactation the ruminant mammary gland removes relatively large quantities of circulating amino acids (AA) to meet the requirements for milk protein synthesis but arterio-venous uptake studies in dairy cows (1) have indicated that the uptake of certain AA may be insufficient to account for their output as milk protein. The apparent deficit may be accounted for by the use of AA supplied to the gland as small peptides or proteins. A dual-labelled tracer approach involving infusion of [13C]-labelled peptides into the external pudic artery which supplies blood directly to the mammary gland demonstrated that dipeptide-bound AA can be utilised as direct precursors for milk casein synthesis in lactating dairy goats (2). However, previous studies using vascular infusion of [13C]-labelled free AA (3) have provided equivocal data on involvement of non-labelled extra-mammary derived peptides/proteinsin vivoin the biosynthesis of milk protein.

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Identification of circRNA-Associated-ceRNA Networks Involved in Milk Fat Metabolism under Heat Stress

International Journal of Molecular Sciences ◽

10.3390/ijms21114162 ◽

2020 ◽

Vol 21 (11) ◽

pp. 4162

Author(s):

Dongyang Wang ◽

Zujing Chen ◽

Xiaona Zhuang ◽

Junyi Luo ◽

Ting Chen ◽

...

Keyword(s):

Fatty Acids ◽

Heat Stress ◽

Mammary Gland ◽

Dairy Cows ◽

Milk Fat ◽

Unsaturated Fatty Acids ◽

Negative Impact ◽

Biological Activities ◽

Fat Metabolism ◽

Milk Quality

Summer temperatures are generally high in Southern China, and cows are likely to suffer a heat stress reaction. Heat stress will have a negative impact on the performance of dairy cows; however, the mechanism by which high temperature affects lactation is not clear. CircRNA is a type of non-coding RNA discovered in recent years, which performs a crucial function in many biological activities. However, the effects of circRNA on lactation function of dairy cows under heat stress is unknown. The present study aimed to explore the expression levels of circRNA in the mammary gland tissue of cows under heat stress. Firstly, we collected blood and milk samples of summer and winter cows and evaluated lactation performance using serum indicators, milk production, and milk composition. Incorporating the calculation of the temperature and humidity index, we conformed the heat stress status of cows in summer. Heat stress increased the concentration of HSP70 and decreased the concentration of SOD and PRL. Heat stress not only reduced milk yield but also affected milk quality, with milk lactose and milk protein decreasing with increased temperature. The analysis of the fatty acid composition in summer milk found significantly reduced concentrations of unsaturated fatty acids, especially long-chain unsaturated fatty acids. Sequencing of the cow’s mammary gland transcriptome revealed that compared to the appropriate temperature (ST) group, the heat stress (HS) group had a total of 2204 upregulated and 3501 downregulated transcripts. GO enrichment and KEGG pathway analysis showed that these genes were mainly related to milk fat metabolism. In addition, 19 upregulated and 19 downregulated circRNA candidates were found in response to heat stress. We used Pearson’s test to establish the correlation of circRNA-mRNA and identified four pairs of circRNA-miRNA networks between four circRNAs, six miRNAs, and the CD36 gene. In this study, we revealed the possible role of circRNAs in lactation of dairy cows and identified that circRNA-miRNA-mRNA networks might exist in the cow’s mammary glands, providing valuable experience for dairy lactation and milk quality.

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Feeding concentrates based on individual cow requirements improves the yield of milk solids in dairy cows grazing restricted pasture

Australian Journal of Experimental Agriculture ◽

10.1071/ea05349 ◽

2007 ◽

Vol 47 (5) ◽

pp. 502 ◽

Cited By ~ 15

Author(s):

S. C. García ◽

M. Pedernera ◽

W. J. Fulkerson ◽

A. Horadagoda ◽

K. Nandra

Keyword(s):

Dairy Cows ◽

Milk Fat ◽

Milk Protein ◽

Nutrient Balance ◽

Maize Silage ◽

Fixed Rate ◽

Milk Protein Content ◽

Holstein Friesian ◽

Fat Yield ◽

Milk Solids

A grazing experiment involving 50 lactating Holstein–Friesian dairy cows was conducted to test the hypothesis that feeding concentrates (range 3–7 kg as fed/cow.day; average 5 kg/cow.day) to grazing cows based on individual (I) cow requirements would increase milk solids yield in comparison to fixed rate (F) allocation to the whole herd (average 5 kg/cow.day for all cows). The experiment comprised two sequential periods that differed only in the way maize silage was offered to cows (either 100% on a feed pad at night or 75% on a feed pad at night, with 25% in a paddock in the morning). Intake of individual cows was estimated using the 13C and n-alkanes method. The rumen degradability of the feeds (lucerne pasture, maize silage and commercial dairy pellets) was measured in parallel, using six rumen-fistulated sheep. Compared with cows in the F group, milk yield and milk fat yield for the I cows increased (P < 0.05) by 3.0 and 11.1%, respectively. As neither milk protein content nor milk protein yield was affected (P > 0.05) by treatment, total milk solids yield (milk fat plus milk protein) was 7.0% higher (P < 0.05) for I cows than for F cows. The increase in milk fat yield was presumably associated with an improved diet nutrient balance in the I cows, as indicated by a significant correlation between fibre intake and milk fat yield for cows in the I group but not for cows in the F group. This is also supported by the results of the rumen degradability of the feeds. In this study, higher-producing cows compensated for their higher requirements by increasing intake of maize silage, rather than pasture, as the former was the less restricted feed on offer. This highlights the importance of offering at least one feed to cows in a less restricted way, in order to enable high-producing cows in the herd to compensate for their higher intake requirements. In conclusion, under the conditions of the present study, feeding concentrates to cows based on individual cow requirements increased milk solids yield at no extra cost.

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Whole-body fluxes and partitioning of amino acids to the mammary gland of cows fed fresh pasture at two levels of intake during early lactation

British Journal Of Nutrition ◽

10.1079/bjn2003886 ◽

2003 ◽

Vol 90 (2) ◽

pp. 271-281 ◽

Cited By ~ 3

Author(s):

D. Pacheco ◽

M.H. Tavendale ◽

G. W. Reynolds ◽

T. N. Barry ◽

J. Lee ◽

...

Keyword(s):

Amino Acids ◽

Protein Synthesis ◽

Mammary Gland ◽

Dairy Cows ◽

Milk Protein ◽

Essential Amino Acids ◽

Whole Body ◽

Early Lactation ◽

Isoleucine Leucine ◽

Ad Libitum

The utilisation of essential amino acids (EAA) by the mammary gland of lactating dairy cows fed fresh forages was studied to provide basic information useful in designing strategies to increase the production of milk protein from pasture-fed dairy cows. The relationship between the flux of EAA in the whole body and their uptake by the mammary gland was determined in four cows in early lactation (length of time in milk 44 (SD 14·5) d) producing 21 (SD 4·0) kg milk/d. The cows were maintained in metabolism stalls and fed fresh perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) pasturead libitumor restricted to 75 %ad libitumintake. The whole-body fluxes of amino acids (AA) were measured using an arterio-venous infusion of universally13C-labelled AA. Whole-body fluxes of fourteen AA were estimated. Isotope dilution indicated that mammary utilisation accounted for one-third of the whole-body flux of EAA, with individual AA ranging between 17 and 35 %. Isoleucine, leucine, valine and lysine were the EAA with the greatest partitioning towards the mammary gland (up to 36 % of the whole-body flux), which could reflect a potentially limiting effect on milk protein synthesis. In the case of AA with low partitioning to the mammary gland (for example, histidine), it is suggested that non-mammary tissues may have priority over the mammary gland and therefore the supply of this AA may also limit milk protein synthesis.

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Genome-Wide Identification and Functional Prediction of Circular RNAs in Response to Heat Stress in Chinese Holstein Cows

10.21203/rs.3.rs-51789/v1 ◽

2020 ◽

Author(s):

Ying Qi ◽

Qiuling Li ◽

Yuemei Guo ◽

Mingxing Chu ◽

Yiming Zhang ◽

...

Keyword(s):

Heat Stress ◽

Mammary Gland ◽

Dairy Cows ◽

Rna Sequencing ◽

Metabolic Regulation ◽

Economic Loss ◽

Circular Rnas ◽

Chinese Holstein ◽

Go Annotation ◽

Negative Effect

Abstract Background: Heat stress (HS) leads to substantial economic loss of dairy industry each year. The negative effect of HS in dairy cows is becoming one of the more urgent and important issue due to accelerating side-effects of global warming. At present, the best way to alleviate the effect of HS is breeding of thermotolerant cows which depends on the profound understanding of mechanism of HS. Various genes are involved in HS response but the information about the role of noncoding RNAs, especially circular RNAs (circRNAs) is largely unknown.Results: In our study, we aimed to investigate the different expression profile of circRNAs between HS and normal condition (NC) of Chinese Holstein cow’s mammary gland. CircRNAs were identified using RNA sequencing and bioinformatics analysis. In total, 37405 circRNAs were detected and 95 were differentially expressed (DE), including 15 downregulated and 80 upregulated circRNAs in HS group compared to NC. Eight circRNAs were randomly selected to verify the RNA sequencing result. Further, Sanger sequencing validated the backsplicing site of the eight circRNAs. Moreover, results obtained from the Quantitative real time PCR (qRT-PCR) showed consistent expression trend with that of RNA sequencing. GO annotation and KEGG analysis suggested that these DE circRNAs probably involved in the energy metabolic regulation. Furthermore, we constructed ceRNA network and the result indicated that these DE circRNAs could regulate lactation through IGF1 and PRL signaling pathway.Conclusion: During our study, it was evident that circRNAs were involved in regulation of HS response in Chinese Holstein cow’s mammary gland. This will help researchers to achieve a better understanding of mechanism related to HS response and can provide new insights in breeding of thermotolerant dairy cows.

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Immune and Metabolic Effects of Rumen-Protected Methionine During a Heat Stress Challenge in Lactating Holstein Cows

Journal of Animal Science ◽

10.1093/jas/skab323 ◽

2021 ◽

Author(s):

R T Pate ◽

D Luchini ◽

J P Cant ◽

L H Baumgard ◽

F C Cardoso

Keyword(s):

Heat Stress ◽

Phase 1 ◽

Dietary Treatment ◽

Metabolic Effects ◽

Holstein Cows ◽

Phase 2 ◽

Amyloid A ◽

Serum Haptoglobin ◽

Environmental Treatment ◽

Dietary Treatments

Abstract Multiparous, lactating Holstein cows (n = 32) were randomly assigned to 1 of 2 dietary treatments [TMR with rumen-protected Met (RPM) or TMR without RPM (CON)], and within each dietary treatment group cows were randomly assigned to 1 of 2 environmental treatment groups in a split-plot crossover design. In phase 1 (9 d) all cows were fed ad libitum and in thermoneutral conditions (TN). In phase 2 (9 d), group 1 (n = 16) was exposed to a heat stress (HS) challenge (HSC). Group 2 cows (n = 16) were pair-fed (PFTN) to HSC counterparts and remained in TN. After a 21-d washout period, the study was repeated (period 2) and the environmental treatments were inverted relative to treatments from phase 2 of period 1, while dietary treatments remained the same for each cow. During phase 1, cows in RPM had greater plasma Met concentration compared to cows in CON (59 µM and 30 µM, respectively; P < 0.001). Cows in PFTN had a greater decrease (P < 0.05) in plasma insulin than cows in HSC at 4 h (-2.7 µIU/mL vs. -0.7 µIU/mL) and 8 h (-7.7 µIU/mL vs. -0.4 µIU/mL) during phase 2. Compared to cows in PFTN, cows in HSC had an increase (P < 0.05) in plasma serum amyloid A (-59 µg/mL vs. +58 µg/mL), serum haptoglobin (-3 µg/mL vs. +33 µg/mL), plasma lipopolysaccharide binding protein (-0.27 µg/mL and +0.11 µg/mL), and plasma interleukin-1β (-1.9 pg/mL and +3.9 pg/mL) during phase 2. In conclusion, HSC elicited immunometabolic alterations; however, there were limited effects of RPM on cows in HSC.

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Amino Acid Metabolism in Dairy Cows and their Regulation in Milk Synthesis

Current Drug Metabolism ◽

10.2174/1389200219666180611084014 ◽

2019 ◽

Vol 20 (1) ◽

pp. 36-45 ◽

Cited By ~ 2

Author(s):

Feiran Wang ◽

Haitao Shi ◽

Shuxiang Wang ◽

Yajing Wang ◽

Zhijun Cao ◽

...

Keyword(s):

Protein Synthesis ◽

Mammary Gland ◽

Dairy Cows ◽

Milk Fat ◽

Milk Protein ◽

Regulatory Element ◽

Mammalian Target Of Rapamycin ◽

Input Output ◽

Output Ratio ◽

Group 2

Background: Reducing dietary Crude Protein (CP) and supplementing with certain Amino Acids (AAs) has been known as a potential solution to improve Nitrogen (N) efficiency in dairy production. Thus understanding how AAs are utilized in various sites along the gut is critical. Objective: AA flow from the intestine to Portal-drained Viscera (PDV) and liver then to the mammary gland was elaborated in this article. Recoveries in individual AA in PDV and liver seem to share similar AA pattern with input: output ratio in mammary gland, which subdivides essential AA (EAA) into two groups, Lysine (Lys) and Branchedchain AA (BCAA) in group 1, input: output ratio > 1; Methionine (Met), Histidine (His), Phenylalanine (Phe) etc. in group 2, input: output ratio close to 1. AAs in the mammary gland are either utilized for milk protein synthesis or retained as body tissue, or catabolized. The fractional removal of AAs and the number and activity of AA transporters together contribute to the ability of AAs going through mammary cells. Mammalian Target of Rapamycin (mTOR) pathway is closely related to milk protein synthesis and provides alternatives for AA regulation of milk protein synthesis, which connects AA with lactose synthesis via α-lactalbumin (gene: LALBA) and links with milk fat synthesis via Sterol Regulatory Element-binding Transcription Protein 1 (SREBP1) and Peroxisome Proliferatoractivated Receptor (PPAR). Conclusion: Overall, AA flow across various tissues reveals AA metabolism and utilization in dairy cows on one hand. While the function of AA in the biosynthesis of milk protein, fat and lactose at both transcriptional and posttranscriptional level from another angle provides the possibility for us to regulate them for higher efficiency.

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Influence of Ruminal Starch Degradability on Performance of High Producing Dairy Cows

10.32747/1994.7568748.bard ◽

1994 ◽

Author(s):

John Tal Huber ◽

Joshuah Miron ◽

Brent Theurer ◽

Israel Bruckental ◽

Spencer Swingle

Keyword(s):

Mammary Gland ◽

Dairy Cows ◽

Protein Production ◽

Milk Protein ◽

Amino Nitrogen ◽

Research Project ◽

Sorghum Grain ◽

Steam Flaking ◽

Urea Recycling ◽

Total Starch

This research project entitled "Influence of Ruminal Starch Degradability on Performance of High Producing Dairy Cows" had the following objectives: a) Determine effects of feeding varying amounts of ruminally degradable starch (RDS) on efficiency of milk and milk protein production; and 2) Investigate digestive and metabolic mechanisms relating to lactation responses to diets varying in ruminal and total starch degradability. Four lactation studies with high producing cows were conducted in which steam-flaked (~ 75% RDS) was compared with dry-rolled sorghum (~ 50% RDS) grain. All studies demonstrated increased efficiency of conversion of feed to milk (FCM/DMI) and milk protein as amount of RDS in the diet increased by feeding steam-flaked sorghum. As RDS in diets increased, either by increased steam-flaked sorghum, grinding of sorghum, or increasing the proportion of wheat to sorghum, so also did ruminal and total tract digestibilities of starch and neutral-detergent soluble (NDS) carbohydrate. Despite other research by these two groups of workers showing increased non-ammonia N (NAN) flowing from the rumen to the duodenum with higher RDS, only one of the present studies showed such an effect. Post-absorptive studies showed that higher dietary RDS resulted in greater urea recycling, more propionate absorption, a tendency for greater output of glucose by the liver, and increased uptake of alpha-amino nitrogen by the mammary gland. These studies have shown that processing sorghum grain through steam-flaking increases RDS and results in greater yields and efficiency of production of milk and milk protein in high producing dairy cows.

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Effects of sequential feeding with adjustments to dietary amino acid concentration according to the circadian rhythm on the performance, body composition, and nutrient balance of growing-finishing pigs

PLoS ONE ◽

10.1371/journal.pone.0261314 ◽

2021 ◽

Vol 16 (12) ◽

pp. e0261314

Author(s):

Alini Mari Veira ◽

Luan Sousa dos Santos ◽

Paulo Henrique Reis Furtado Campos ◽

Danilo Alves Marçal ◽

Alícia Zem Fraga ◽

...

Keyword(s):

Body Composition ◽

Phase 1 ◽

Nutrient Balance ◽

Average Daily Gain ◽

Finishing Pigs ◽

Phase 2 ◽

Phase 3 ◽

Body Protein ◽

Feeding Program ◽

Daily Gain

This study aimed to evaluate the effects of a sequential feeding program (SEQ) with diets varying in amino acid (AA) concentrations in the first and last 12 h of the day on the performance, body composition, and nutrient balance of growing-finishing pigs. Sixty-eight castrated male pigs were distributed in four treatments: a daily feeding program (DP) and three SEQs. In the DP, dietary requirements of AA were adjusted daily. In the SEQ, dietary daily requirements of AA were adjusted every 12 h, providing a low AA concentration in period 1 (P1; 00:00–11:59 h) and a high AA concentration in period 2 (P2; 12:00–23:59 h). In the SEQ, three different levels of low and high AA concentrations were evaluated: ±20%, ±30%, and ±40%. The experiment lasted 82 days and was divided into phase 1 (25–50 kg body weight; BW), phase 2 (50–70 kg BW), and phase 3 (70–100 kg BW). During phase 1, irrespective of dietary AA concentration, SEQ pigs had higher lysine intake, protein gain, and phosphorus efficiency than DP pigs (P ≤ 0.05). Pigs in the SEQ showed a tendency for greater average daily gain, body protein, and body lipids compared to the DP pigs (P ≤ 0.10). During phase 2, SEQ pigs showed a tendency for higher average feed intake in P2 compared to DP pigs (P = 0.07); consequently, average daily gain, body protein, and phosphorus retention tended to increase (P ≤ 0.10). During phase 3, SEQ pigs had a higher average feed intake in P2 than DP pigs (P = 0.03). However, they had a similar body composition (P > 0.05) and a tendency for higher nitrogen excretion (P = 0.06) than DP pigs. Our results suggest that SEQ is an effective approach for improving the performance and body composition of growing pigs.

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