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1.
J Agric Food Chem ; 67(40): 11167-11178, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31542928

RESUMO

Milk contains a number of beneficial fatty acids including short and medium chain and unsaturated conjugated and nonconjugated fatty acids. In this study, microRNA sequencing of mammary tissue collected in early-, peak-, mid-, and late-lactation periods was performed to determine the miRNA expression profiles. miR-16a was one of the differentially expressed miRNA and was selected for in-depth functional studies pertaining to fatty acid metabolism. The mimic of miR-16a impaired fat metabolism [triacylglycerol (TAG) and cholesterol] while knock-down of miR-16a promoted fat metabolism in vitro in bovine mammary epithelial cells (BMECs). In addition, the in vitro work with BMECs also revealed that miR-16a had a negative effect on the cellular concentration of cis 9-C18:1, total C18:1, C20:1, and C22:1 and long-chain polyunsaturated fatty acids. Therefore, these data suggesting a negative effect on fatty acid metabolism extend the discovery of the key role of miR-16a in mediating adipocyte differentiation. Through a combination of bioinformatics analysis, target gene 3' UTR luciferase reporter assays, and western blotting, we identified large tumor suppressor kinase 1 (LATS1) as a target of miR-16a. Transfection of siRNA-LATS1 into BMECs led to increases in TAG, cholesterol, and cellular fatty acid concentrations, suggesting a positive role of LATS1 in mammary cell fatty acid metabolism. In summary, data suggest that miR-16a regulates biological processes associated with intracellular TAG, cholesterol, and unsaturated fatty acid synthesis through LATS1. These data provide a theoretical and experimental framework for further clarifying the regulation of lipid metabolism in mammary cells of dairy cows.


Assuntos
Bovinos/metabolismo , Células Epiteliais/enzimologia , Metabolismo dos Lipídeos , Glândulas Mamárias Animais/enzimologia , MicroRNAs/metabolismo , Leite/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Bovinos/genética , Colesterol/metabolismo , Células Epiteliais/metabolismo , Ácidos Graxos/metabolismo , Feminino , Regulação da Expressão Gênica , Glândulas Mamárias Animais/metabolismo , MicroRNAs/genética , Proteínas Serina-Treonina Quinases/genética , Triglicerídeos/metabolismo
2.
J Agric Food Chem ; 67(37): 10513-10520, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31475823

RESUMO

Amino acids can stimulate milk fat synthesis, but the underlying molecular mechanism is still largely unknown. In this study, we studied the regulatory role and corresponding molecular mechanism of cAMP response element-binding protein-regulated transcription coactivator 2 (CRTC2) in amino acid-induced milk fat synthesis in mammary epithelial cells. We showed that leucine and methionine stimulated CRTC2 but not p-CRTC2(Ser171) expression and nuclear localization in cow mammary epithelial cells. Knockdown of CRTC2 decreased milk fat synthesis and sterol regulatory element binding protein 1c (SREBP-1c) expression and activation, whereas its overexpression had the opposite effects. Neither knockdown nor overexpression of CRTC2 affected ß-casein synthesis and phosphorylation of the machanistic target of rapamycin (mTOR), suggesting that CRTC2 only regulates milk fat synthesis. CRTC2 knockdown abolished the stimulation of leucine and methionine on SREBP-1c expression and activation. Knockdown or overexpression of CRTC2 did not affect the protein level of cAMP-response element-binding protein (CREB) and its phosphorylation but decreased or increased the binding of p-CREB to the promoter of SREBP-1c gene and its mRNA expression, respectively. Mutation of Ser171 of CRTC2 did not alter the stimulation of CRTC2 on SREBP-1c expression and activation, further suggesting that CRTC2 functions in the nucleus. mTOR inhibition by rapamycin totally blocked the stimulation of leucine and methionine on CRTC2 expression. The expression of CRTC2 was dramatically higher in the mouse mammary gland of lactation period, compared with that of the dry and puberty periods, whereas p-CRTC2(Ser171) was not changed, further supporting that CRTC2 is a key transcription coactivator for milk fat synthesis. These results uncover that CRTC2 is a key transcription coactivator of amino acid-stimulated mTOR-mediated milk fat synthesis in mammary epithelial cells.


Assuntos
Aminoácidos/metabolismo , Bovinos/metabolismo , Células Epiteliais/metabolismo , Gorduras/metabolismo , Glândulas Mamárias Animais/citologia , Leite/metabolismo , Fatores de Transcrição/metabolismo , Animais , Bovinos/genética , Feminino , Glândulas Mamárias Animais/metabolismo , Camundongos , Fosforilação , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Fatores de Transcrição/genética
3.
J Agric Food Chem ; 67(38): 10756-10763, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31483626

RESUMO

AFEX treatment of crop residues can greatly increase their nutrient availability for ruminants. This study investigated the concentration of acetamide, an ammoniation byproduct, in AFEX-treated crop residues and in milk and meat from ruminants fed these residues. Acetamide concentrations in four AFEX-treated cereal crop residues were comparable and reproducible (4-7 mg/g dry matter). A transient acetamide peak in milk was detected following introduction of AFEX-treated residues to the diet, but an alternative regimen showed the peak can be effectively mitigated. Milk acetamide concentration following this transition was 6 and 10 ppm for cattle and buffalo, respectively, but also decreased over time for cattle while tending to decrease (p = 0.08) for buffalo. There was no difference in acetamide concentration in the meat of cattle consuming AFEX-treated residues for 160 days compared to controls. Further investigation is necessary to determine the metabolism of acetamide in ruminants and a maximum acceptable daily intake for humans.


Assuntos
Acetamidas/análise , Ração Animal/análise , Bovinos/metabolismo , Produtos Agrícolas/química , Resíduos de Drogas/análise , Contaminação de Alimentos/análise , Carne/análise , Leite/química , Acetamidas/metabolismo , Amônia/química , Animais , Búfalos , Dieta/veterinária , Digestão , Leite/metabolismo
4.
Int J Food Microbiol ; 308: 108304, 2019 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-31425789

RESUMO

Streptococcus thermophilus strains are used in fermented dairy products for their capacity to metabolize lactose into lactic acid. The rate of lactic acid production in milk is of major economic importance, as rapid acidification prevents growth of undesirable microorganisms. It is also of paramount significance for aroma, texture and flavor of the end product. Besides achieving customer satisfaction, improvement of production rate and operational costs incite industrials into selecting fast acidifying strains. Another important trait of S. thermophilus influencing acidification is the urease, which catabolizes urea into ammonia and has a detrimental effect on acidification. Unfortunately, most of the S. thermophilus strains possess the urease, and the urease-negative ones are necessary for industrial applications. Urease activity is a widely distributed activity in S. thermophilus species, and urease-negative strains are rare. The later are however interesting from an industrial point of view, as they may give faster acidification in dairy applications, because lactic acid is not buffered by urea-derived ammonia. Nowadays, the efforts to improve the characteristics of strains for industrial applications are based on natural strategies such as random mutagenesis. This implies the need of a screening method that is efficient in terms of time and success. In this context, the aim of this study was the development of a new medium that allows selection of urease-defective mutants based on S. thermophilus colony morphology. Discrimination capacity of the new medium was verified using previously characterized urease-negative recombinant strains. The new milk-based medium, applied to industrial S. thermophilus strains subjected to UV mutagenesis, allowed the selection of 3 mutants, partially or completely defective in urease activity. Genetic characterization of urease-defective mutants highlighted the presence of nonsense or missense mutations in the ureA, ureC and ureG genes, thus supporting their phenotype. Evaluation of milk acidification revealed increased performance for one out of three urease-defective mutants compared to wild-type strains.


Assuntos
Amônia/metabolismo , Streptococcus thermophilus/genética , Streptococcus thermophilus/metabolismo , Ureia/metabolismo , Urease/genética , Animais , Ácido Láctico/biossíntese , Lactose/metabolismo , Leite/metabolismo , Fenótipo
5.
J Dairy Sci ; 102(10): 9468-9480, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31400898

RESUMO

Reducing milk production during early lactation might be of interest to improve the energy balance (EB) of high-yielding dairy cows. Therefore, the objective of this study was to determine how reducing the milking frequency (MF) of high-yielding dairy cows from thrice to twice a day during the first 30 d in milk (DIM) affects yields, intake, efficiency, metabolic status, and carryover effects. To this end, 42 multiparous cows were divided into 2 groups according to their previous lactation performance, parity, and body weight. The control cows were milked 3 times a day (3ML) and the treated cows were milked twice a day (2ML) until 30 DIM and then both groups were milked 3 times a day. Milk samples were taken twice a week from 2 or 3 consecutive milkings until 45 DIM for analysis of milk solids, and both groups were followed until 100 DIM to determine the carryover effects of MF until 30 DIM. Individual dry matter intake (DMI), milk yield, and body weight were recorded daily. Blood samples were taken 3 times weekly from 14 d prepartum until 45 DIM. Milk yield during the first 30 DIM was 8.6% higher (49.3 and 45.4 kg/d, respectively), milk fat percentage was lower (3.96 and 4.27%, respectively), and the yields of all milk solids were higher in the 3ML cows than in the 2ML cows. Dry matter intake and 4% fat-corrected milk were similar between groups. The EB during the first 30 DIM was lower in the 3ML cows than in the 2ML cows, and milk yield, but not 4% fat-corrected milk yield, per unit of DMI was higher in the 3ML cows. No differences were observed between groups from 31 to 100 DIM in milk yield (∼56.3 kg/d for both groups), milk solids yield, DMI, or milk/DMI; however, fat percentage was lower and EB was higher in the 3ML cows. Blood glucose concentrations between 0 and 30 DIM were lower and ß-hydroxybutyrate concentrations were higher in the 3ML cows than in the 2ML cows, but nonesterified fatty acids concentrations were lower, which may be attributed to the lower clearance frequency of nonesterified fatty acids from the blood stream in the 2ML cows. A lower proportion of the 3ML cows (10%) ovulated ≤15 DIM compared with the 2ML cows (40%), with no beneficial effects on preovulatory follicle characteristics. Reducing the MF from thrice to twice a day during the first 30 DIM improved EB and metabolic status, with only minor effects on production.


Assuntos
Bovinos/fisiologia , Metabolismo Energético , Leite/metabolismo , Ácido 3-Hidroxibutírico/sangue , Animais , Peso Corporal , Colostro , Indústria de Laticínios , Ácidos Graxos não Esterificados/sangue , Feminino , Lactação , Paridade , Gravidez
6.
J Dairy Sci ; 102(10): 9488-9494, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31421876

RESUMO

Ample research has described the assessment of dimensional changes for different teat traits, whereas diagnostic techniques to reliably assess blood circulation in teats of dairy cows are limited. Here, we describe the development and evaluation of a scanning technique to quantify blood flow in teats of dairy cows using power Doppler ultrasonography. In 2 consecutive trials, 384 teat scans [trial 1, n = 256 (sagittal plane, n = 128; transverse plane, n = 128); trial 2, n = 128 (transverse plane)] from 16 cows were obtained by the same 2 operators. Perfusion intensity from single images (trial 1) and video images (trial 2) were assessed using a commercially available software program. Intraclass correlation coefficients (ICC) and concordance correlation coefficients (CCC) were used to assess interoperator reproducibility (agreement between measurements performed by different operators) and intraoperator repeatability (agreement between measurements performed by the same operator). In trial 1, interoperator ICC and CCC indicated poor agreement (ICC ≤0.26, CCC ≤0.26). Intraoperator ICC and CCC demonstrated poor agreement between duplicate measurements within operators (ICC ≤0.19, CCC ≤0.19). Modifications after trial 1 included (1) a different ultrasound device, (2) analysis of video clips rather than single images, (3) restriction to 1 sectional plane (i.e., transverse), and (4) a scanning sequence such that repeated scans within operators were measured one after another. Through these modifications, intraoperator repeatability in trial 2 yielded fair to good agreement, with intraoperator ICC and CCC over both operators ranging from 0.44 to 0.70 and from 0.57 to 0.69, respectively, whereas interoperator ICC and CCC showed poor agreement (ICC = 0.35, CCC = 0.34). We conclude that repeatable measurements of blood perfusion intensity of teats in dairy cows can be attained with power Doppler ultrasonography. Power Doppler ultrasonography is a suitable tool to quantify slow flow in small vessels and may be an acceptable diagnostic technique to assess changes in blood circulation that result from machine milking in teats of dairy cows, although further research is necessary to validate this hypothesis.


Assuntos
Bovinos/sangue , Leite/metabolismo , Software , Ultrassonografia Doppler/veterinária , Animais , Feminino , Glândulas Mamárias Animais/irrigação sanguínea , Glândulas Mamárias Animais/diagnóstico por imagem , Mamilos/irrigação sanguínea , Mamilos/diagnóstico por imagem , Fenótipo , Reprodutibilidade dos Testes
7.
J Agric Food Chem ; 67(34): 9532-9542, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31369265

RESUMO

Murine mammary gland is an ideal model for studying the development and milk synthesis in dairy animals. MicroRNAs play an important role in milk synthesis and mammary gland development; however, the molecular mechanism of miR-142-3p continues to be poorly understood. Here, we knocked down miR-142-3p expression in vitro and vivo, increased the prolactin receptor expression and activated many downstream cellular proteins, such as mammalian target of rapamycin, sterol regulatory element-binding transcription factor 1, cyclin D1, and signal transducer and activator of transcription 5. Additionally, miR-142-3p knockdown in mouse mammary gland epithelial cells increased proliferation but not viability, induced cell cycle progression, decreased apoptosis, and increased the expression of triglycerides and ß-casein. Moreover, miR-142-3p knockdown in murine mammary gland tissue in vivo affected the structure and function of the mammary gland, which showed an increased number of lobules and ducts and was more capable of producing milk. However, overexpression of miR-142-3p had the opposite effects. In summary, these data reveal that miR-142-3p regulates milk synthesis and the structure of murine mammary glands via PRLR-mediated multiple signaling pathways.


Assuntos
Glândulas Mamárias Animais/metabolismo , MicroRNAs/metabolismo , Leite/metabolismo , Receptores da Prolactina/metabolismo , Animais , Caseínas/metabolismo , Células Epiteliais/metabolismo , Feminino , Glândulas Mamárias Animais/crescimento & desenvolvimento , Camundongos , Camundongos Endogâmicos BALB C , MicroRNAs/genética , Receptores da Prolactina/genética , Transdução de Sinais , Triglicerídeos/metabolismo
8.
J Agric Food Chem ; 67(34): 9477-9491, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31429552

RESUMO

Lipopolysaccharide (LPS) is a bacterial endotoxin that induces intestine inflammation. Milk exosomes improve the intestine and immune system development of newborns. This study aims to establish the protective mechanisms of porcine milk exosomes on the attenuation of LPS-induced intestinal inflammation and apoptosis. In vivo, exosomes prevented LPS-induced intestine damage and inhibited (p < 0.05) LPS-induced inflammation. In vitro, exosomes inhibited (p < 0.05) LPS-induced intestinal epithelial cells apoptosis (23% ± 0.4% to 12% ± 0.2%). Porcine milk exosomes also decreased (p < 0.05) the LPS-induced TLR4/NF-κB signaling pathway activation. Furthermore, exosome miR-4334 and miR-219 reduced (p < 0.05) LPS-induced inflammation through the NF-κB pathway and miR-338 inhibited (p < 0.05) the LPS-induced apoptosis via the p53 pathway. Cotransfection with these three miRNAs more effectively prevented (p < 0.05) LPS-induced cell apoptosis than these miRNAs individual transfection. The apoptosis percentage in the group cotransfected with the three miRNAs (14% ± 0.4%) was lower (p < 0.05) than that in the NC miRNA group (28% ± 0.5%), and also lower than that in each individual miRNA group. In conclusion, porcine milk exosomes protect the intestine epithelial cells against LPS-induced injury by inhibiting cell inflammation and protecting against apoptosis through the action of exosome miRNAs. The presented results suggest that the physiological amounts of miRNAs-enriched exosomes addition to infant formula could be used as a novel preventative measure for necrotizing enterocolitis.


Assuntos
Apoptose , Células Epiteliais/citologia , Exossomos/metabolismo , MicroRNAs/metabolismo , Leite/metabolismo , NF-kappa B/metabolismo , Receptor 4 Toll-Like/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Células Epiteliais/metabolismo , Exossomos/genética , Mucosa Intestinal/citologia , Mucosa Intestinal/metabolismo , Lipopolissacarídeos/efeitos adversos , Masculino , Camundongos , MicroRNAs/genética , NF-kappa B/genética , Transdução de Sinais , Suínos , Receptor 4 Toll-Like/genética , Proteína Supressora de Tumor p53/genética
9.
Res Vet Sci ; 125: 244-252, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31323525

RESUMO

Bovine milk contains different components with nutritional and immunological benefits. It is easily accessible and a rich source of potential markers reflective of pathophysiological conditions; however, little is known about the changes in protein abundance associated with variation across breeds and seasons. In this study, we performed a comprehensive proteomic profiling of whey proteins from Holstein Friesian cow and Murrah buffalo across summer and winter seasons. Collectively, 490 proteins were identified with 113 and 144 differentially expressed proteins across seasons in cow and buffalo, respectively. Breed specific proteins like secretoglobin, e-cadherin and cathepsin-L were detected exclusively in HF, while basigin, conglutinin, and thrombomodulin were identified exclusively in Mu. Acute phase proteins (e.g. haptoglobin and α1AG) were more abundant in summer while antimicrobial proteins (e.g. conglutinin and osteopontin) were upregulated in winter. Similarly, proteins involved in lipid homeostasis (e.g. perilipin 2 and acyl CoA binding protein) showed breed specific variations. Selected representative mass spectrometric proteins (e.g. gelsolin and osteopontin) were validated by Western blot analysis. Results of this study indicate the dynamic nature of milk protein and provide a foundation for future studies of whey proteins which may be linked to diseases specific across breeds and seasons.


Assuntos
Búfalos/fisiologia , Bovinos/fisiologia , Estações do Ano , Proteínas do Soro do Leite/química , Soro do Leite/química , Animais , Feminino , Leite/metabolismo , Proteômica/métodos , Especificidade da Espécie , Proteínas do Soro do Leite/metabolismo
10.
J Dairy Sci ; 102(10): 9548-9557, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31326172

RESUMO

Recommended milking practices (RMP) are protective against mastitis. However, many producers do not adopt, or only partially adopt, these measures. This study aimed to explore the attitudes and perceptions of Ontario dairy farmers toward barriers to implementation of RMP and to investigate what motivates behavior change in relation to milking hygiene. Four focus groups with Ontario dairy producers were conducted, and verbatim transcripts were analyzed thematically. The main barriers to adoption of RMP were identified and categorized into 2 groups: intrinsic barriers and physical barriers. Intrinsic barriers included personal habits and convenience, not perceiving udder health as a priority on their farm, and lack of information. Physical barriers included employee training and compliance, convenience of implementing RMP, and time, money, and labor barriers. Producers used their bulk tank somatic cell count (SCC) as a measure of perceived severity of udder health problems on farm. Those with lower SCC were less likely to prioritize udder health compared with peers experiencing elevations in SCC. Lack of udder health problems translated for some producers into non-adoption of certain RMP, as they felt these practices were not needed unless a problem arose. Others felt motivated to implement more practices and work toward better udder health if such efforts translated into rewards for better-quality milk. Some producers perceived RMP as not meaningful or useful, seemingly due to a lack of education about the reasons behind RMP implementation. Understanding the importance of these practices is one key to implementing them. To overcome some of the intrinsic barriers, increased efforts in knowledge translation are needed, including efforts in retraining current practices, as well as in establishing best practices.


Assuntos
Atitude , Indústria de Laticínios/métodos , Fazendeiros/psicologia , Higiene , Mastite Bovina/prevenção & controle , Leite/metabolismo , Animais , Bovinos , Contagem de Células/veterinária , Fazendas , Feminino , Glândulas Mamárias Animais , Motivação , Ontário
11.
J Dairy Sci ; 102(10): 9495-9504, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31351712

RESUMO

Through clearing and use of fertilizer and legumes, areas of southwestern Australia's unique coastal sand plains can support relatively low-cost dairies. However, the ancient, highly weathered nature of the soils in this region makes the dairies susceptible to a range of threats, including nutrient leaching and erosion. Despite this, Western Australian dairy cows typically produce up to 5,500 L of milk per head annually supported by inorganic nitrogen (N) fertilizer (commonly 50:50 urea and ammonium sulfate) at rates up to <320 kg of N/ha per year. Where hotspots exist (up to 2,000 kg of N/ha per year), total N exceeds pasture requirements. We investigated plant and soil bacteria responses to N fertilizer rates consistent with Australian legislated production practices on dairy farms for pure and mixed swards of white clover (Trifolium repens) and Italian ryegrass (Lolium multiflorum) in a long-term pasture experiment in controlled glasshouse conditions. Although the soil bacterial community structure at phylum level was similar for white clover and Italian ryegrass, relative abundances of specific subgroups of bacteria differed among plant species according to the N fertilizer regimen. Marked increases in relative abundance of some bacterial phyla and subphyla indicated potential inhibition of N cycling, especially for N hotspots in soil. Ammonium concentration in soil was less correlated with dominance of some N-cycling bacterial phyla than was nitrate concentration. Changes in bacterial community structure related to altered nutrient cycling highlight the potential for considering this area of research in policy assessment frameworks related to nutrient loads in dairy soils, especially for N.


Assuntos
Bactérias/efeitos dos fármacos , Bovinos/metabolismo , Fertilizantes/microbiologia , Lolium/crescimento & desenvolvimento , Leite/metabolismo , Nitrogênio/farmacologia , Microbiologia do Solo , Trifolium/crescimento & desenvolvimento , Animais , Austrália , Bactérias/crescimento & desenvolvimento , Feminino , Itália , Nitratos/farmacologia , Nitrogênio/metabolismo
12.
J Dairy Sci ; 102(10): 9525-9535, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31351723

RESUMO

Dairy processing uses a significant amount of water for processing and cleaning. Withdrawing and distributing water and treating wastewater represent significant costs to the Irish dairy processing industry. Stringent discharge limits also add pressure for water use efficiency, particularly during peak production months. Improving water use efficiency is therefore critical for Irish dairy processing. We conducted a detailed analysis of water use efficiency in 4 Irish dairy processing plants. Using farm gate to processor gate (gate-to-gate) life cycle assessment, we assessed on-site water data quality and investigated gate-to-gate volumetric water use and eutrophication potential (EP) for 3 common dairy products. We also benchmarked the on-site water use and water balance, characterized wastewater nutrient load, analyzed the influencers of on-site water use, and identified scope for increased water use efficiency. We found that condensate from evaporation represented a significant input at the site level (0.51 to 1.14 L/L of fresh water purchased or extracted from nature). In terms of gate-to-gate volumetric water use, butter used 1,326 to 1,843 m3/t of solids, with electricity being the largest contributor, whereas milk powders used 3,006 to 3,754 m3/t of solids, with electricity and ingredients being the largest contributors. Eutrophication of butter was found to be 0.51 to 0.77 kg of PO4 equivalents (eq)/t of solids, with transportation and nutrient emissions from wastewater treatment being the largest contributors. Eutrophication of milk powder was found to be 0.96 to 3.35 kg of PO4 eq/t of solids, and contributions varied depending on powder specifications. Milk intake water use and various leakages were found to be hotspots that could be managed to reduce water use on site. Comprehensive metering is urgently needed to improve water use efficiency in light of the ongoing expansion of dairy production and hence processing in Ireland. Significant opportunities exist to optimize operator behavior, water reuse, and off-site transportation and energy. This study represents the first attempt to define water efficiency opportunities both at the site level and along the supply chain. Processors need to be aware of off-site contributors that significantly affect both volumetric water use and environmental impacts of processed dairy products.


Assuntos
Meio Ambiente , Leite/metabolismo , Águas Residuárias , Água , Animais , Manteiga , Indústria de Laticínios , Eutrofização , Irlanda , Transportes
13.
J Dairy Sci ; 102(10): 9512-9517, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31351724

RESUMO

This study aimed to compare measurements of methane (CH4) and carbon dioxide (CO2) concentrations in the breath of dairy cows kept in commercial conditions using the Fourier-transform infrared spectroscopy (FTIR) and nondispersive infrared spectroscopy (NDIR) methods. The measurement systems were installed in an automated milking system. Measurements were carried out for 5 d using both systems during milkings. The measurements were averaged per milking, giving 467 observations of CH4 and CO2 concentrations of 44 Holstein Friesian cows. The Pearson correlation between observations from the 2 systems was 0.86 for CH4, 0.84 for CO2, and 0.88 for their ratio. The repeatability of FTIR (0.53 for CH4, 0.57 for CO2, and 0.28 for their ratio) was somewhat higher than that of NDIR (0.57 for CH4, 0.47 for CO2, and 0.25 for their ratio). The coefficient of individual agreement was 0.98 for CH4, 0.89 for CO2, and 0.89 for their ratio; the concordance correlation coefficient was 0.48 for both gases and 0.24 for their ratio. We showed that FTIR and NDIR give similar results in commercial farm conditions. They can therefore be used interchangeably to generate a larger data set, which could then be further used for genetic evaluation.


Assuntos
Dióxido de Carbono/análise , Bovinos/fisiologia , Metano/análise , Leite/metabolismo , Espectrofotometria Infravermelho/veterinária , Espectroscopia de Infravermelho com Transformada de Fourier/veterinária , Animais , Feminino
14.
J Dairy Sci ; 102(10): 9481-9487, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31351729

RESUMO

The main objective of this study was to evaluate the risk factors for late embryonic loss (LEL) in supplemented grazing dairy cows. Additional objectives were to assess the incidence of LEL and its association with the reproductive performance of cows. A data set containing productive, reproductive, and health records of 13,551 lactations was used. A retrospective case-control study involving 631 cows with LEL (cases) and 2,524 controls (4 controls per case within each study year) was run. A case of LEL was defined when the embryo had no heartbeat or there was evidence of detached membranes or floating structures including embryo remnants by ultrasonography (US) at 28 to 42 d post-artificial insemination (AI), whereas a non-case was defined as a cow diagnosed with positive pregnancy by US 28 to 42 d post-AI and reconfirmed as pregnant 90 ± 7 d post-AI. Four controls per case were randomly selected from the non-cases with a temporal matching criterion (±3 d around the date of the fecundating AI of the case). Multivariable logistic models were offered with the following predictors: year of LEL (2011 through 2015), season of LEL (summer vs. fall vs. winter vs. spring), parity (1 vs. 2 vs. ≥3), uterine disease (UD), non-uterine disease (NUD), body condition score at parturition, body condition score at 28 to 42 d post-AI (BCS-LEL), days in milk (DIM), and daily milk yield (MY). Statistical significance was set at P < 0.05 and a tendency was set at P ≤ 0.10. We found that 4.7, 22, and 23% of cows had LEL, UD, and NUD, respectively. Cases tended to have higher daily MY than controls (32.5 vs. 31.8 kg); also, cases had much longer calving to pregnancy interval (226 vs. 118 d), lower hazard of pregnancy [hazard ratio = 0.39, 95% confidence interval (CI) = 0.35-0.43], and higher odds for non-pregnancy [odds ratio (OR) = 2.89, 95% CI = 2.37-3.54] than controls. We found that the odds for LEL increased with parity number (OR = 2.48, 95% CI = 1.99-3.08 for parity ≥3) and with BCS-LEL <2.50 (OR = 1.81, 95% CI = 1.33-2.47). Conversely, the odds for LEL decreased with BCS-LEL >3.00 (OR = 0.70, 95% CI = 0.53-0.91). The odds for LEL increased with UD (OR = 1.23, 95% CI = 1.01-1.49), NUD (OR = 1.24, 95% CI = 1.01-1.54), DIM (OR = 1.03, 95% CI = 1.00-1.05), and daily MY (OR = 1.14, 95% CI = 1.04-1.25) in univariable models only. Finally, the odds for LEL were not associated with year, season, DIM, and body condition score at parturition. In conclusion, LEL is associated with extended calving to pregnancy interval, and among its risk factors are parity number and BCS-LEL.


Assuntos
Bovinos/fisiologia , Suplementos Nutricionais , Leite/metabolismo , Reprodução , Animais , Estudos de Casos e Controles , Bovinos/embriologia , Feminino , Inseminação Artificial/veterinária , Lactação , Paridade , Gravidez , Estudos Retrospectivos , Fatores de Risco
15.
J Agric Food Chem ; 67(31): 8485-8492, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31304752

RESUMO

How short-chain fatty acids (FAs) affect cell membrane morphology and milk fat biosynthesis in mammary epithelial cells (MECs) is yet unclear. This study investigated the primary bovine MEC response to different FAs. We observed that the cell surface ultrastructures were influenced by chain length and degree of saturability of FAs. The CD36, FATP1, and FABP3 gene expression was affected independent of the type of FA. FASN, LPIN1, PPARα, and PPARγ transcripts were more sensitive to the short-chain FAs (acetic and ß-hydroxybutyric acids). Furthermore, short-chain FAs inclined to regulate FA degradation-, elongation-, and metabolism-associated pathways, while long-chain FAs (stearic and trans-10,cis-12 conjugated linolenic acids) modulated extracellular matrix-receptor interaction-, transcriptional misregulation-, microRNA-, and ribosome biogenesis-related pathways. However, triacylglycerol accumulation in the cytoplasm was not changed by all of the FAs. Overall, FAs with different chain lengths and degrees of saturability could differentially alter primary bovine MEC cell morphology and influence protein profiles involved in milk fat synthesis pathways.


Assuntos
Bovinos/metabolismo , Células Epiteliais/metabolismo , Gorduras/metabolismo , Ácidos Graxos não Esterificados/química , Ácidos Graxos não Esterificados/metabolismo , Glândulas Mamárias Animais/metabolismo , Leite/metabolismo , Animais , Antígenos CD36/genética , Antígenos CD36/metabolismo , Bovinos/genética , Gorduras/química , Proteínas de Transporte de Ácido Graxo/genética , Proteínas de Transporte de Ácido Graxo/metabolismo , Feminino , Glândulas Mamárias Animais/citologia , Leite/química , PPAR alfa/genética , PPAR alfa/metabolismo , Triglicerídeos/metabolismo
16.
J Sci Food Agric ; 99(14): 6515-6521, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31321772

RESUMO

BACKGROUND: Fortification of animal products with natural bioactive compounds appears to improve their quality and protects consumers against oxidation effects. An experiment was therefore conducted to examine the effects of hesperidin or naringin on milk oxidative stability, yield, composition, coagulation properties, and the fatty acid profile in dairy sheep. Thirty-six Chios ewes were assigned to four groups. A control group was fed a concentrate diet without supplementation. The other three groups were provided with the same diet further supplemented with hesperidin (6000 mg kg-1 ), naringin (6000 mg kg-1 ), or α-tocopheryl acetate (200 mg kg-1 ). The efficacy of flavonoids after a change in diet composition that lowered milk oxidation values by itself was also tested. The duration of the experiment was 28 days with alfalfa hay being the only forage source for the first 14 days, whereas after the 15th day a mixture of alfalfa hay and wheat straw (65:35) was provided. RESULTS: The oxidative stability of milk was improved after 14 days of addition of the examined flavonoids (P < 0.05). Milk malondialdehyde (MDA) values were also decreased as a result of flavonoid dietary supplementation, 14 days after the modification of the forage source. On the other hand, no significant differences in yield, chemical composition, coagulation properties, and fatty acid profile of ewe milk were observed among the treatments throughout the experiment. CONCLUSION: Enrichment of dairy ewes' diets with hesperidin and naringin might be effective in improving milk's oxidative stability without any effects on the milk's chemical composition, coagulation properties, and fatty acid profile. © 2019 Society of Chemical Industry.


Assuntos
Suplementos Nutricionais/análise , Flavanonas/administração & dosagem , Hesperidina/administração & dosagem , Leite/metabolismo , Ovinos/metabolismo , Ração Animal/análise , Animais , Ácidos Graxos/análise , Ácidos Graxos/metabolismo , Feminino , Leite/química , alfa-Tocoferol/análise , alfa-Tocoferol/metabolismo
17.
J Dairy Sci ; 102(9): 8385-8399, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31301833

RESUMO

The primary objective of the present study was to estimate the effect of Streptococcus agalactiae intramammary infection on milk production and somatic cell count (SCC) in Norwegian dairy cows. A secondary objective was to assess differences in the effect of common Strep. agalactiae sequence types (ST) found in Norwegian dairy herds. We performed a cohort study combining registry data with sequence-type data from Strep. agalactiae isolates. Herds in which Strep. agalactiae had been detected in individual animals (bacteriological culture or quantitative PCR) between 2012 and 2015 were included. We accessed monthly test-day milk yield records for the entire period to compare milk yield and SCC between cows that were Strep. agalactiae positive and all other cows, within each herd. The study sample consisted of 150 herds, 15,757 cows, 30,850 lactations, and 204,126 test days. We evaluated the effects of Strep. agalactiae on test-day milk yield and SCC using mixed linear regression models, controlling for clustering by herd, cow, and lactation. Multilocus sequence typing of Strep. agalactiae was available for isolates from 86 herds. Additional models were fit to a subset of herds (n = 59) in which ST1, ST23, ST103, and ST196 had been found, to compare the effects of ST on milk production and SCC. In the period 3 to 2 mo before diagnosis, Strep. agalactiae-positive cows produced an average of 1.3 kg more DIM-adjusted milk/d than their negative herd mates. At the time of diagnosis, production was on average 0.13 kg less DIM-adjusted milk/d in Strep. agalactiae-positive cows than in negative cows; 2 to 3 mo after diagnosis, they produced 1.24 kg less DIM-adjusted milk/d than negative cows. Losses persisted for the rest of the investigated period. Cows with ST23, ST103, and ST196 followed a similar pattern as the overall analysis with respect to milk production, whereas ST1-affected cows produced similar amounts of milk before diagnosis as the negative cows. Cows with ST1 experienced the largest milk loss 1 to 2 mo after diagnosis but then recovered to some extent; for cows with ST103, the severe milk loss persisted for the rest of the investigation period. The cow-associated ST103 elicited a lower response in peak SCC compared with ST23, ST103, and ST196. The results indicate an effect of Strep. agalactiae on milk production and SCC. Production was lowest 2 to 3 mo after a positive sample. Peak SCC was reached the month before diagnosis, with notable differences between sequence types.


Assuntos
Mastite Bovina/fisiopatologia , Leite , Streptococcus agalactiae , Animais , Bovinos , Contagem de Células/veterinária , Estudos de Coortes , Indústria de Laticínios , Feminino , Lactação , Modelos Lineares , Mastite Bovina/patologia , Leite/metabolismo
18.
J Dairy Sci ; 102(9): 8417-8422, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31301848

RESUMO

The objective of this study was to evaluate the accuracy of inline milk fat-to-protein (F:P) data to detect hyperketonemia (HYK) in herds with automated milking systems (AMS). The F:P ratio has been investigated as a tool for detecting HYK with moderate accuracy in past studies, but inline F:P data in AMS may also be useful for HYK screening. To assess the accuracy of these data in commercial settings, we monitored 484 cows from 9 AMS herds for their first 3 wk of lactation, taking blood samples once per week (n = 1,427). Positive cases of HYK were defined by whole-blood ß-hydroxybutyrate (BHB) concentrations ≥1.2 or ≥1.4 mmol/L. Milk data were collected from the AMS software on each farm for each cow and converted into 4 different F:P values: (1) value from the same day as the BHB test; (2) 5-d centered-moving average (CMA); (3) 5-d backward-moving average (BMA); (4) 5-d forward-moving average (FMA). In linear regression models, all 4 values were associated with BHB, but slope estimates varied and R2 were low: same day (slope = 0.95, R2 = 0.07), CMA (slope = 1.05, R2 = 0.07), BMA (slope = 0.65, R2 = 0.04), and FMA (slope = 1.23, R2 = 0.09). In logistic regression models, the odds of having HYK (BHB ≥1.2 mmol/L) increased with every 0.1-unit increase from the mean F:P ratio (1.16) using same-day values (odds ratio = 1.35, 95% confidence interval = 1.25-1.47) and CMA (odds ratio = 1.39, 95% confidence interval = 1.27-1.51). The same increase in F:P from mean BMA (1.14) and FMA (1.17) was associated with 1.22 and 1.49 times the odds of HYK, respectively. For all 4 F:P variations, we evaluated the sensitivity, specificity, positive predictive value, and negative predictive value of different F:P thresholds with HYK status. As the F:P threshold increased from 1.17 to 1.50, sensitivity decreased (range: 77 to 9%) but specificity increased (range: 58 to 96%). Same-day and CMA F:P cutoffs at which a balance was reached between sensitivity and specificity ranged from 1.18 to 1.22; however, even at these values we found high rates of false positives and negatives (range: 31-39%). These results suggest that inline milk F:P data from inconsistently calibrated sensors should not be used alone to detect HYK in AMS herds.


Assuntos
Doenças dos Bovinos/diagnóstico , Gorduras/metabolismo , Cetose/veterinária , Proteínas do Leite/metabolismo , Leite/metabolismo , Ácido 3-Hidroxibutírico/sangue , Animais , Automação , Bovinos , Doenças dos Bovinos/sangue , Indústria de Laticínios/métodos , Feminino , Cetose/sangue , Cetose/diagnóstico , Lactação , Modelos Lineares , Modelos Logísticos , Sensibilidade e Especificidade
19.
J Dairy Sci ; 102(8): 6959-6970, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31255265

RESUMO

In this paper, we report the physicochemical and sensory properties of milk supplemented with a powder of microencapsulated lactase. The core material was lactase (ß-galactosidase), the primary coating material was medium-chain triglyceride (MCT), and the secondary (enteric) coating material was either hydroxypropyl methylcellulose phthalate (HPMCP) or shellac, comparing both against market milk as a control. The physicochemical properties of both types of microcapsules were analyzed, including the particle size, zeta potential, and in vitro release behavior. To survey the stability of the microcapsules in milk during storage, we studied the residual lactose content and pH. Furthermore, to determine the properties of milk supplemented with the microcapsules, changes in color and sensory properties were evaluated during storage. The particle sizes (volume-weighted mean; D[4,3]) of the microcapsules coated with HPMCP or shellac were 2,836 and 7,834 nm, respectively, and the zeta potential of the capsules coated with shellac was higher than the zeta potential of those coated with HPMCP. The pH levels of milk supplemented with the lactase microcapsules were similar to those of the control (unsupplemented market milk); however, for milk supplemented with HPMCP-coated microcapsules, the pH was slightly lower. The core material, lactase, was released from the microcapsules during 12-d storage, and 18.82 and 35.09% of lactose was hydrolyzed in the samples for HPMCP- and shellac-coated microcapsules, respectively. The sensory characteristics of milk containing microcapsules coated with HPMCP did not show significant differences from the control, in terms of sweetness or off-taste, until 8 d of storage. However, shellac-coated microcapsules showed significant difference in sweetness and off-taste at d 8 and 6 of storage, respectively. The color of milk containing HPMCP-coated microcapsules did not show a significant difference during storage. However, that containing shellac-coated microcapsules was somewhat higher in color values than others. In particular, it showed significance from 0 to 4 d storage in L* and C* values. In conclusion, a powder of lactase microcapsules coated with HPMCP can be suitable as a supplement for milk.


Assuntos
Suplementos Nutricionais , Kluyveromyces/enzimologia , Lactase/administração & dosagem , Metilcelulose/análogos & derivados , Leite/química , Animais , Cápsulas , Fenômenos Químicos , Composição de Medicamentos/veterinária , Proteínas Fúngicas/administração & dosagem , Hidrólise , Lactose/metabolismo , Metilcelulose/química , Leite/metabolismo , Tamanho da Partícula , Pós , Resinas Vegetais/química , Paladar , Triglicerídeos/química
20.
J Dairy Sci ; 102(9): 7619-7639, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31301829

RESUMO

The physiological control of lactation through coordinated adaptations is of fundamental importance for mammalian neonatal life. The putative actions of reduced insulin sensitivity and responsiveness and enhanced adipose tissue lipolysis spare glucose for the mammary synthesis of milk. However, severe insulin antagonism and body fat mobilization may jeopardize hepatic health and lactation in dairy cattle. Interestingly, lipolysis- and dietary-derived fatty acids may impair insulin sensitivity in cows. The mechanisms are undefined yet have major implications for the development of postpartum fatty liver disease. In nonruminants, the sphingolipid ceramide is a potent mediator of saturated fat-induced insulin resistance that defines in part the mechanisms of type 2 diabetes mellitus and nonalcoholic fatty liver disease. In ruminants including the lactating dairy cow, the functions of ceramide had remained virtually undescribed. Through a series of hypothesis-centered studies, ceramide has emerged as a potential antagonist of insulin-stimulated glucose utilization by adipose and skeletal muscle tissues in dairy cattle. Importantly, bovine data suggest that the ability of ceramide to inhibit insulin action likely depends on the lipolysis-dependent hepatic synthesis and secretion of ceramide during early lactation. Although these mechanisms appear to fade as lactation advances beyond peak milk production, early evidence suggests that palmitic acid feeding is a means to augment ceramide supply. Herein, we review a body of work that focuses on sphingolipid biology and the role of ceramide in the dairy cow within the framework of hepatic and fatty acid metabolism, insulin function, and lactation. The potential involvement of ceramide within the endocrine control of lactation is also considered.


Assuntos
Bovinos/fisiologia , Ceramidas/fisiologia , Esfingolipídeos/fisiologia , Animais , Indústria de Laticínios , Dieta/veterinária , Ácidos Graxos/metabolismo , Feminino , Insulina/fisiologia , Lactação/fisiologia , Fígado/metabolismo , Leite/metabolismo
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