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1.
Anim Sci J ; 91(1): e13454, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32959464

RESUMO

This study investigated the effects of substituting ear corn silage (ECS) for commercial formula feed on milk production and milk fatty acid profiles in grazing dairy farms during the summer season. A field survey was conducted on five grazing dairy farms in every summer month of 2017, 2018, and 2019. Three of the five farms substituted fresh ECS for the commercial formula feed at a ratio of 2:1 from July of each year (ECS farms). Other farms maintained the same feeding management as before (non-ECS farms). An interview survey was conducted on each farm to calculate feed intake and milk yield per cow. Feed and milk samples were collected in each survey. Milk compositions and milk fatty acid profiles were determined. The substitution of ECS for the commercial formula feed did not affect milk yield or milk composition, but ECS farms maintained low levels of milk urea compared with non-ECS farms (p < .01). The ECS substitution also influenced some of the milk fatty acid proportions; C16:0 and C16:1 increased, and trans-11 C18:1, cis-9,trans-11 C18:2, and the sum of polyunsaturated fatty acids decreased, while these fatty acid proportions were maintained in non-ECS farms throughout the summer season (p < .05).


Assuntos
Ração Animal , Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Bovinos/metabolismo , Bovinos/fisiologia , Indústria de Laticínios , Dieta/veterinária , Suplementos Nutricionais , Ácidos Graxos/análise , Herbivoria/fisiologia , Lactação/fisiologia , Leite/metabolismo , Silagem , Zea mays , Animais , Feminino
2.
PLoS One ; 15(9): e0239308, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32956396

RESUMO

BACKGROUND: Vitamin A deficiency is highly prevalent in low-income countries and is a major public health problem worldwide. Lactating mothers are the most vulnerable population group to vitamin A deficiency. Despite this, there is limited study on vitamin A-rich food consumption by lactating mothers in Ethiopia. Therefore, this study aimed to assess adequate vitamin A rich food consumption and associated factors among lactating mothers visiting child immunization and postnatal care centers in health institutions of Gondar Town. METHODS: An Institution-based cross-sectional study design was employed at a health institution in Gondar Town from February to March 2019, and included 631 study participants. Simple random sampling followed by a systematic sampling technique was used to select participants. The data were collected using the Helen Keller International Food Frequency Questionnaire, entered using Epi-Info 7 statistical software and exported to STATA version 14 for analysis. A multivariable logistic regression analysis was used to identify factors associated with the outcome variable and variables with p-value <0.05 were considered as statistically significant. RESULT: A total of 624 lactating mothers participated in the study giving a response rate of 98.89%. The study shows adequate consumption of vitamin A-rich food was 38.94% (95% CI: 35%- 43%). Predictors such as attending college diploma and above (AOR = 2.26, 95% CI; 1.02-4.99), having household family size ≤ 3 (AOR = 4.04, 95% CI; 1.60-10.17), being in higher economic class (AOR = 1.93, 95% CI; 1.18-3.14), having dietary diversity score of ≥ 5 (AOR = 1.59, 95% CI; 1.09-2.32) and meal frequency of ≥ 4 (AOR = 1.64, 95% CI; 1.09-2.32) were statistically significant. CONCLUSION AND RECOMMENDATION: The majority of respondents had inadequate consumption of foods rich in vitamin A. Educational status, family size, wealth index, dietary diversity, and meal frequency were found to be factors that affect adequate consumption of vitamin A-rich foods. Encouraging and educating lactating mothers to consume foods rich in vitamin A is crucial.


Assuntos
Dieta , Lactação/efeitos dos fármacos , Deficiência de Vitamina A/dietoterapia , Vitamina A/uso terapêutico , Adulto , Instituições de Assistência Ambulatorial , Criança , Etiópia/epidemiologia , Características da Família , Feminino , Humanos , Imunização/métodos , Lactação/fisiologia , Masculino , Refeições , Pessoa de Meia-Idade , Mães , Estado Nutricional , Pobreza , Prevalência , Deficiência de Vitamina A/epidemiologia , Deficiência de Vitamina A/metabolismo
3.
Adv Exp Med Biol ; 1252: 3-7, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32816256

RESUMO

The mature breast is located within the anterior thoracic wall, lying atop the pectoralis major muscle. Pubertal changes lead to incomplete development of the breast , a process which is only completed during pregnancy . The incomplete breast consists mostly of adipose tissue but also lactiferous units called lobes. These eventually drain into the lactiferous ducts and then into the lactiferous sinus and then to the nipple-areolar complex. During pregnancy , the breast undergoes both anatomic and physiologic changes to prepare for lactation. During the first trimester, the ductal system expands and branches out into the adipose tissue in response to the increase of estrogen. Elevated levels of estrogen also cause a decrease in adipose tissue and ductal proliferation and elongation. Estrogen also stimulates the pituitary gland which leads to elevated levels of prolactin. By the twentieth week of gestation, mammary glands are sufficiently developed to produce components of milk due to prolactin stimulation. Milk production is inhibited by high estrogen and progesterone levels and colostrum is produced during this time. In the third trimester and then rapidly after birth, these levels decrease, allowing for milk production and eventual let-down to allow for breastfeeding. Most pregnancies cause the areola to darken, the breast to increase in size, and the Montgomery glands to become more prominent. Post-lactational involution occurs at the cessation of milk production caused by a decline in prolactin.


Assuntos
Mama/anatomia & histologia , Mama/fisiologia , Lactação/fisiologia , Gravidez/fisiologia , Estrogênios , Feminino , Humanos , Leite Humano , Parto , Prolactina
4.
Adv Exp Med Biol ; 1252: 9-16, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32816257

RESUMO

Physical exam of the breast is a very important part of breast assessment both for breast cancer screening, and when approaching breast lesions. Examination during pregnancy and breastfeeding follows exactly the same method as non-pregnancy periods. However, physical changes that occur in the breast during these times due to hormonal effects cause alterations that can on one hand conceal some pathologic disorders, and may on the other hand appear as pathologic findings while being purely physiologic. This chapter focuses first on some key points for an accurate breast examination, and then reviews some challenging controversial findings that may be noticed during breast exam in a pregnant or lactating woman.


Assuntos
Doenças Mamárias/diagnóstico , Mama/anatomia & histologia , Mama/patologia , Lactação/fisiologia , Exame Físico , Mama/fisiologia , Doenças Mamárias/patologia , Aleitamento Materno , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/patologia , Feminino , Humanos , Gravidez
5.
Adv Exp Med Biol ; 1252: 27-32, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32816259

RESUMO

Breast tissue reveals some physiologic changes during pregnancy and lactation due to hormonal alterations. Whole range of breast diseases including inflammatory, benign and malignant neoplasms can be seen in pregnancy but due to concurrent physiologic changes, may lead to diagnostic challenges. This chapter reviews sampling methods and histologic features of common benign breast lesions in pregnancy and lactation periods.


Assuntos
Doenças Mamárias/patologia , Mama/citologia , Mama/patologia , Lactação/fisiologia , Complicações na Gravidez , Gravidez/fisiologia , Neoplasias da Mama/patologia , Feminino , Humanos
6.
PLoS One ; 15(8): e0235357, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760112

RESUMO

We evaluated the between-cow (b-cow) variation and repeatability in omasal and milk fatty acids (FA) related to methane (CH4) emission. The dataset was originated from 9 studies with rumen-cannulated dairy cows conducted using either a switch-back or a Latin square design. Production of CH4 per mole of VFA (Y_CH4VFA) was calculated based on VFA stoichiometry. Experiment, diet within experiment, period within experiment, and cow within experiment were considered as random factors. Empirical models were developed between the variables of interest by univariate and bivariate mixed model regression analysis. The variation associated with diet was higher than the b-cow variation with low repeatability (< 0.25) for milk odd- and branch-chain FA (OBCFA). Similarly, for de novo synthesized milk FA, diet variation was ~ 3-fold greater than the b-cow variation; repeatability for these FA was moderate to high (0.34-0.58). Also, for both cis-9 C18:1 and cis-9 cis-12 cis-15 C18:3 diet variation was more than double the b-cow variation, but repeatability was moderate. Among the de novo milk FA, C4:0 was positively related with stoichiometric Y_CH4VFA, while for OBCFA, anteiso C15:0 and C15:0 were negatively related with it. Notably, when analyzing the relationship between omasal FA and milk FA we observed positive intercept estimates for all the OBCFA, which may indicate endogenous post-ruminal synthesis of these FA, most likely in the mammary gland. For milk iso C13:0, iso C15:0, anteiso C15:0, and C15:0 were positively influenced by omasal proportion of their respective FA and by energy balance. In contrast, the concentration of milk C17:0, iso C18:0, C18:0, cis-11 C18:1, and cis-9 cis-12 cis-15 C18:3 were positively influenced by omasal proportion of their respective FA but negatively related to calculated energy balance. Our findings demonstrate that for most milk FA examined, a larger variation is attributed to diet than b-cow differences with low to moderate repeatability. While some milk FA were positively or negatively related with Y_CH4VFA, there was a pronounced effect of calculated energy balance on these estimates. Additionally, even though OBCFA have been indicated as markers of rumen function, our results suggest that endogenous synthesis of these FA may occur, which therefore, may limit the utilization of milk FA as a proxy for CH4 predictions for cows fed the same diet.


Assuntos
Variação Biológica da População , Efeito Estufa , Lactação/fisiologia , Metano/metabolismo , Leite/química , Ração Animal , Animais , Bovinos , Indústria de Laticínios , Conjuntos de Dados como Assunto , Ácidos Graxos/análise , Feminino , Rúmen/metabolismo
7.
PLoS One ; 15(8): e0235806, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32756565

RESUMO

INTRODUCTION: Oxytocin is a key hormone in breastfeeding. No recent review on plasma levels of oxytocin in response to breastfeeding is available. MATERIALS AND METHODS: Systematic literature searches on breastfeeding induced oxytocin levels were conducted 2017 and 2019 in PubMed, Scopus, CINAHL, and PsycINFO. Data on oxytocin linked effects and effects of medical interventions were included if available. RESULTS: We found 29 articles that met the inclusion criteria. All studies had an exploratory design and included 601 women. Data were extracted from the articles and summarised in tables. Breastfeeding induced an immediate and short lasting (20 minutes) release of oxytocin. The release was pulsatile early postpartum (5 pulses/10 minutes) and coalesced into a more protracted rise as lactation proceeded. Oxytocin levels were higher in multiparous versus primiparous women. The number of oxytocin pulses during early breastfeeding was associated with greater milk yield and longer duration of lactation and was reduced by stress. Breastfeeding-induced oxytocin release was associated with elevated prolactin levels; lowered ACTH and cortisol (stress hormones) and somatostatin (a gastrointestinal hormone) levels; enhanced sociability; and reduced anxiety, suggesting that oxytocin induces physiological and psychological adaptations in the mother. Mechanical breast pumping, but not bottle-feeding was associated with oxytocin and prolactin release and decreased stress levels. Emergency caesarean section reduced oxytocin and prolactin release in response to breastfeeding and also maternal mental adaptations. Epidural analgesia reduced prolactin and mental adaptation, whereas infusions of synthetic oxytocin increased prolactin and mental adaptation. Oxytocin infusion also restored negative effects induced by caesarean section and epidural analgesia. CONCLUSIONS: Oxytocin is released in response to breastfeeding to cause milk ejection, and to induce physiological changes to promote milk production and psychological adaptations to facilitate motherhood. Stress and medical interventions during birth may influence these effects and thereby adversely affect the initiation of breastfeeding.


Assuntos
Aleitamento Materno , Lactação/sangue , Ocitocina/sangue , Hormônio Adrenocorticotrópico/sangue , Ansiedade/sangue , Feminino , Humanos , Hidrocortisona/sangue , Lactação/fisiologia , Gravidez , Prolactina/sangue , Estresse Fisiológico
8.
Anim Sci J ; 91(1): e13414, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32618028

RESUMO

The purpose of this paper was to utilize the decision trees technique to determine the factors responsible for high monthly milk yield in Polish Holstein-Friesian cows from 27 herds equipped with milking robots. The applied statistical method-the decision tree technique-showed that the most important factors responsible for monthly milk yield of dairy cows using robots were, in descending order of importance: milking frequency, lactation number, month of milking, and type of lying stall. At the same time, it has been ascertained that the highest monthly milk yield (47.24 kg) can be expected from multiparous cows kept in barns with a deep bedding that were milked more frequently than three times per day. On the other hand, the lowest milk production (13.56 kg) was observed among dairy cows milked less frequently than two times a day, with an average number of milked quarters lower than 3.97. The application of the decision trees technique allows a breeder to select appropriate levels of environmental factors and parameters that will help to ensure maximized milk production.


Assuntos
Bovinos/fisiologia , Indústria de Laticínios/instrumentação , Árvores de Decisões , Lactação/fisiologia , Leite , Robótica , Criação de Animais Domésticos/métodos , Animais , Indústria de Laticínios/métodos , Meio Ambiente , Feminino , Abrigo para Animais , Fatores de Tempo
9.
Sci Rep ; 10(1): 9421, 2020 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-32523093

RESUMO

Although shedding of zoonotic brucellae in milk has been demonstrated in natural hosts, these data are still missing for the standard murine infection model. We therefore analysed shedding kinetics and the niche of B. melitensis in murine milk. Pregnant Balb/cByJ mice were intraperitoneally infected with 105 CFU of the 16 M reference strain, a 16 M mCherry mutant or a human isolate. Milk was collected over the course of lactation, and subjected to culture and immunofluorescence assays. Bacteria were also quantified in spleen and mammary glands of maternal mice and in spleen of the litter. The shedding of the three strains did not differ significantly (p = 0.301), ranging from log10 1.5 to 4.04 CFU/ml. A total of 73% of the mice excreted B. melitensis into the milk with peak values at mid-lactation; up to 30 bacteria/cell were found in macrophages and neutrophils. While the bacterial counts in the spleen of lactating females confirmed a well-established infection, only 50% of the pups harboured brucellae in their spleen, including the spleen of an uninfected pup fed by an infected foster mother. In conclusion, the murine model of infection may contribute to a better understanding of the zoonotic transmission of brucellosis.


Assuntos
Brucella melitensis/fisiologia , Brucelose/microbiologia , Macrófagos/microbiologia , Leite/microbiologia , Animais , Modelos Animais de Doenças , Feminino , Lactação/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Gravidez , Baço/microbiologia , Virulência/fisiologia
10.
J Dairy Sci ; 103(8): 6741-6750, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32505406

RESUMO

Hepatic de novo production of glucose and oxidation of fatty acids are critical in supporting milk production during the transition to lactation period. During this period of metabolic challenge, there is an increase in fatty acids taken up by the liver. Although the primary fate for these fatty acids is complete oxidation, alternative fates include incomplete oxidation via ketogenesis, storage within the liver as triglycerides (TG), and secretion of TG within very low density lipoproteins. Influencing the relative capacity of these pathways, and thus shifting nutrient partitioning, may allow for improved hepatic efficiency and metabolic health. Hepatic nutrient partitioning reflects complex regulation of key metabolic pathways by factors such as fatty acids and other substrates. Relative flux of fatty acid through oxidation or re-esterification to TG leads to the onset of metabolic disorders that are associated with negative production outcomes, such as hyperketonemia and fatty liver. Although recent work has focused on understanding how stored TG are lipolyzed for subsequent oxidation, the mechanism and regulation of this remains unclear. The source of mobilized fatty acids is similarly important, both in terms of amount and profile of fatty acids mobilized. There is likely a complex, coordinated whole-body response, given that fatty acids mobilized from adipose tissue affect hepatic regulation. Fatty acids mobilized from adipose tissue have regulatory effects on genes such as pyruvate carboxylase; however, in vivo work suggests there may also be other influences resulting in differential regulation between cows that subsequently develop sub-clinical ketosis and those that do not. Optimizing nutrient partitioning between critical metabolic pathways may allow for nutritional opportunities to reduce incidence of metabolic challenges and improve feed efficiency. Although further research is needed to continue refining our understanding of the intricate balance regulating hepatic metabolism, shifting nutrient partitioning may be key in supporting both efficiency and metabolic health.


Assuntos
Bovinos/metabolismo , Ácidos Graxos/metabolismo , Lactação , Fígado/metabolismo , Nutrientes/metabolismo , Tecido Adiposo/metabolismo , Animais , Distinções e Prêmios , Doenças dos Bovinos/metabolismo , Feminino , Lactação/fisiologia , Leite/metabolismo
11.
An Acad Bras Cienc ; 92 Suppl 1: e20181058, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32491133

RESUMO

The aim of this study was to evaluate the influence of two sub-periods of the calving season and two cow maturity stages on the efficiency of beef cows and their calves. A total of 159 cow-calf pairs were divided by calving time (early or late) within the calving season and maturity stage (young or adult). Calves were weaned at 42 or 63 days after birth and evaluated until 210 days of age. Cows and calves had their development examined based on their weight and body condition score at calving, at weaning, and at 210 days. Reproductive performance was evaluated on the basis of time to become pregnant again. Milk yield was assessed by the direct method on three occasions spaced 21 days apart. Adult cows were heavier than young cows, at calving (398.5 vs 327.5 kg, respectively), weaning (397.3 vs 324.1 kg, respectively) at the end breeding season (424.1 vs 342.1 kg, respectively). Reproductive performance was influenced by calving time. Adult cows had higher pregnancy rates (83.75 and 69.17%, for early and for late calving, respectively) than young cows (57.03 and 35.01% for early and for late-calving, respectively). Calves from early-calving young cows weighed 158.8 kg at 210 days of age vs. 123.7 kg for those born from late-calving adult cows. However, late-calving cows produced 10.7% more milk than those that calved early in the season (227.0 vs 205.0 liters, respectively). Early calving associated with non-requirement of growth determine higher productivity efficiency in beef cows.


Assuntos
Fatores Etários , Bovinos/crescimento & desenvolvimento , Lactação/fisiologia , Reprodução/fisiologia , Ganho de Peso/fisiologia , Animais , Animais Lactentes/crescimento & desenvolvimento , Bovinos/fisiologia , Feminino , Gravidez , Carne Vermelha , Estações do Ano
12.
Toxicol Appl Pharmacol ; 401: 115077, 2020 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-32479917

RESUMO

Triclocarban (TCC) is an antimicrobial compound, widely used in personal care products, such as soaps, toothpaste, and shampoo. This agent is incompletely removed by wastewater treatment and represents an environmental contaminant. Studies show that TCC has been associated with some endocrine disruptions. In vitro, TCC demonstrated potent androgen-augmenting activity and aromatase inhibition. In this sense, exposure during critical periods of development (gestation and lactation) could lead to some adverse health outcomes in offspring. Therefore, the present study evaluated if maternal exposure to three different doses of TCC could interfere in the reproductive parameters of male offspring. Pregnant female Wistar rats were separated into four groups: vehicle Control (CTR); TCC 0.3 mg/kg (TCC 0.3); TCC 1.5 mg/kg (TCC 1.5); TCC 3.0 mg/kg (TCC 3.0). Dams were treated daily by oral gavage from gestational day 0 to lactational day 21. The males were evaluated in different timepoint: infancy (PND 21), puberty (PND 50) and adult life (PND 90-120). The histomorphometric analysis of testis and testosterone level were assessed on PND 21, 50, 120; sexual behavior and sperm parameters at adulthood. In the TCC 3.0 group, a decrease in the testis interstitial volume and an increase in testosterone levels were observed on PND 21. Moreover, there was a decrease in the diameter of the seminiferous tubules on PND 50, and a decrease in sexual competency in adulthood. These results suggest that exposure to a human relevant dose of TCC may interfere with reproduction and could have implications for human health.


Assuntos
Anti-Infecciosos Locais/toxicidade , Carbanilidas/toxicidade , Lactação/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Reprodução/efeitos dos fármacos , Comportamento Sexual Animal/efeitos dos fármacos , Fatores Etários , Animais , Feminino , Lactação/fisiologia , Masculino , Gravidez , Efeitos Tardios da Exposição Pré-Natal/sangue , Efeitos Tardios da Exposição Pré-Natal/patologia , Ratos , Ratos Wistar , Reprodução/fisiologia , Comportamento Sexual Animal/fisiologia , Testículo/efeitos dos fármacos , Testículo/patologia , Testosterona/sangue
13.
Anim Sci J ; 91(1): e13389, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32515521

RESUMO

Efforts to improve dairy performance have been focused on increasing milk productivity of cows through improved feeding systems and genetic potential. However, methods for evaluating milking system performance based on milk productivity have not yet been established. Milking system performance was evaluated by measuring the claw vacuum at five flow rates (1.9-8.7 kg/min) produced using a flow simulator for a single eight-swing milking parlor with a high-line system. Based on these results, a double eight-parallel milking parlor with a low-line system was installed and tested. Farmers can take data obtained from evaluations of milking system performance into account for future management decisions, such as renewing the milking system. By renewing the milking system, average milking productivity, somatic cell linear score (LS) of bulk milk, and LS of each cow were significantly improved in the year after installing the new system (p < .01). In addition to checking conventional milking systems, this novel diagnostic method using a flow simulator can be used for checking new installations and also for proposing renovations.


Assuntos
Bovinos/metabolismo , Bovinos/fisiologia , Indústria de Laticínios/instrumentação , Lactação/fisiologia , Leite/metabolismo , Animais , Indústria de Laticínios/métodos , Feminino , Qualidade dos Alimentos
14.
Anim Sci J ; 91(1): e13391, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32558027

RESUMO

One hundred Yorkshire × Landrace sows were randomly assigned to one of two dietary treatments (diet ND: 6,000 IU vitamin D3 /d feed; diet 25-D: 200 µg/day 25OHD3 feed). The experiment began on d 90 of gestation and continued until weaning on day 21 of lactation. In sows that received 25OHD3 , the growth rate of the piglets before weaning was significantly accelerated (0.266 kg/day, p < .05). Sow serum was collected after weaning, and those in the 25OHD3 group were found to have significantly higher serum calcium (CA) and phosphorus (PI) levels (p < .05). Interestingly, the oestrus cycle of sows fed 25OHD3 was significantly shortened (p < .05), the oestrus time was concentrated on the fifth day after weaning, and the piglets were born with a higher degree of uniformity (p < .05). Colostrum was collected on the day of delivery, and the colostrum of sows fed 25OHD3 contained higher milk fat content than the control group (p < .05). 25OHD3 supplementation increased the mRNA and protein expression of INSIG1 and SREBP1, which regulate milk fat synthesis, in the mammary gland of lactating sows (p < .05). In conclusion, 25OHD3 supplementation in maternal diets improved reproductive performance, milk fat content and the mRNA and protein levels of genes regulating milk fat synthesis in lactating sows.


Assuntos
25-Hidroxivitamina D 2/administração & dosagem , 25-Hidroxivitamina D 2/farmacologia , Fenômenos Fisiológicos da Nutrição Animal/genética , Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Dieta/veterinária , Suplementos Nutricionais , Expressão Gênica/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Lactação/genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Reprodução/efeitos dos fármacos , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Suínos/genética , Suínos/fisiologia , Animais , Cálcio/metabolismo , Estro/efeitos dos fármacos , Feminino , Glicolipídeos/metabolismo , Glicoproteínas/metabolismo , Lactação/fisiologia , Fósforo/metabolismo , Gravidez , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
15.
PLoS One ; 15(6): e0233926, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32492042

RESUMO

This study evaluated 53 primiparous cows (36.8±1.23 months old and 484±40.9 kg of body weight) performance tested (GrowSafe® System) from 22±5 to 190±13 days of lactation in order to obtain daily dry matter intake (DMI). The animals received a high-forage diet (forage-to-concentrate ratio of 90:10). Milk production of the cows was evaluated three times by mechanical milking and the energy-corrected milk yield (ECMY) was calculated. Energy status (through the indicators glucose, cholesterol, triglycerides, and ß-hydroxybutyrate), protein status (indicators albumin, urea, and creatinine), mineral status (indicators calcium, phosphorus, and magnesium), and hormonal status (indicators insulin and cortisol) were estimated four times throughout lactation. The residual feed intake (RFI) of cows was calculated considering DMI, average daily gain (ADG) and mid-test metabolic weight (BW0.75) obtained in early lactation (from 22±5 to 102±7 days), and the animals were classified as negative (most efficient) or positive RFI (least efficient). The RFI model explained 53% of the variation in DMI. The mean DMI, ADG, ECMY, and calf weight as a percentage of cow weight were 12.47±2.70 kg DM/day, 0.632±0.323 kg/day, 10.47±3.23 kg/day, and 36.6±5.39%, respectively. Negative RFI cows consumed 11.5% less DM than positive RFI cows, with performance and metabolic profile being similar to those of positive RFI cows, except for a lower milk protein content and higher blood cholesterol concentration. In conclusion, negative (most efficient) and positive RFI (least efficient) Nellore cows, fed an ad libitum high-forage diet, produced similar amounts of milk, fat and lactose and had similar subcutaneous fat thickness, weight, calf weight as a percentage of cow weight, and blood metabolite concentrations (except for cholesterol). Therefore, there are economic benefits to utilizing RFI in a cow herd since cattle had decreased DMI with similar overall performance, making them more profitable due to lower input costs.


Assuntos
Ração Animal , Criação de Animais Domésticos/métodos , Bovinos/fisiologia , Comportamento Alimentar/fisiologia , Lactação/fisiologia , Fenômenos Fisiológicos da Nutrição Animal , Animais , Feminino , Desmame , Ganho de Peso/fisiologia
17.
J Dairy Sci ; 103(8): 6751-6770, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32448584

RESUMO

Animal welfare can be negatively affected when dairy cattle experience heat stress. Managing heat stress has become more of a challenge than ever before, due to the increasing number of production animals with increased milk yield, and therefore greater metabolic activity. Environmental temperatures have increased by 1.0°C since the 1800s and are expected to continue to increase by another 1.5°C between 2030 and 2052. Heat stress affects production, reproduction, nutrition, health, and welfare. Means exist to monitor and evaluate heat stress in dairy cattle, as well as different ways to abate heat, all with varying levels of effectiveness. This paper is a summary and compilation of information on dairy cattle heat stress over the years.


Assuntos
Bovinos/fisiologia , Resposta ao Choque Térmico , Animais , Temperatura Corporal/fisiologia , Bovinos/psicologia , Indústria de Laticínios , Feminino , Lactação/fisiologia , Masculino , Leite
18.
J Dairy Sci ; 103(7): 6439-6453, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32359988

RESUMO

Dairy cows with high body condition score (BCS) in late prepartum are more susceptible to oxidative stress (OS). Nuclear factor erythroid 2-like 2 (NFE2L2) is a major antioxidant transcription factor. We investigated the effect of precalving BCS on blood biomarkers associated with OS, inflammation, and liver function, along with mRNA and protein abundance of targets related to NFE2L2 and glutathione (GSH) metabolism in s.c. adipose tissue (SAT) of periparturient dairy cows. Twenty-two multiparous Holstein cows were retrospectively classified into a high BCS (HBCS; n = 11, BCS ≥3.5) or normal BCS (NBCS; n = 11, BCS ≤3.17) on d 28 before parturition. Cows were fed a corn silage- and wheat straw-based total mixed ration during late prepartum, and a corn silage- and alfalfa hay-based total mixed ration postpartum. Blood samples obtained at -10, 7, 15, and 30 d relative to parturition were used for analyses of biomarkers associated with inflammation, including albumin, ceruloplasmin, haptoglobin, and myeloperoxidase, as well as OS, including ferric reducing ability of plasma (FRAP), reactive oxygen species (ROS), and ß-carotene. Adipose biopsies harvested at -15, 7, and 30 d relative to parturition were analyzed for mRNA (real-time quantitative PCR) and protein abundance (Western blotting) of targets associated with the antioxidant transcription regulator nuclear factor, NFE2L2, and GSH metabolism pathway. In addition, concentrations of GSH, ROS and malondialdehyde were measured. High BCS cows had lower prepartum dry matter intake expressed as a percentage of body weight along with greater BCS loss between -4 and 4 wk relative to parturition. Plasma concentrations of ROS and FRAP increased after parturition regardless of treatment. Compared with NBCS, HBCS cows had greater concentrations of FRAP at d 7 postpartum, which coincided with peak values in those cows. In addition, NBCS cows experienced a marked decrease in plasma ROS after d 7 postpartum, while HBCS cows maintained a constant concentration by d 30 postpartum. Overall, ROS concentrations in SAT were greater in HBCS cows. However, overall mRNA abundance of NFE2L2 was lower and cullin 3 (CUL3), a negative regulator of NFE2L2, was greater in HBCS cows. Although HBCS cows had greater overall total protein abundance of NFE2L2 in SAT, ratio of phosphorylated NFE2L2 to total NFE2L2 was lower, suggesting a decrease in the activity of this antioxidant system. Overall, mRNA abundance of the GSH metabolism-related genes glutathione reductase (GSR), glutathione peroxidase 1 (GPX1), and transaldolase 1 (TALDO1), along with protein abundance of glutathione S-transferase mu 1 (GSTM1), were greater in HBCS cows. Data suggest that HBCS cows might experience greater systemic OS after parturition, while increased abundance of mRNA and protein components of the GSH metabolism pathway in SAT might help alleviate tissue oxidant status. Data underscored the importance of antioxidant mechanisms at the tissue level. Thus, targeting these pathways in SAT during the periparturient period via nutrition might help control tissue remodeling while allowing optimal performance.


Assuntos
Antioxidantes/metabolismo , Composição Corporal/fisiologia , Bovinos/fisiologia , Glutationa/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Gordura Subcutânea/metabolismo , Animais , Feminino , Humanos , Lactação/fisiologia , Leite/metabolismo , Fator 2 Relacionado a NF-E2/genética , Período Periparto/fisiologia , Gravidez , Espécies Reativas de Oxigênio/metabolismo
19.
PLoS One ; 15(5): e0232400, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32384084

RESUMO

Metabolic parameters ranging from circulating nutrient levels and substrate utilization to energy expenditure and thermogenesis are temporally modulated by the circadian timing system. During critical embryonic developmental periods, maternal over-nutrition could alter key elements in different tissues associated with the generation of circadian rhythmicity, compromising normal rhythmicity development. To address this issue, we determine whether maternal over-nutrition leads to alterations in the development of circadian rhythmicity at physiological and behavioral levels in the offspring. For this, female rabbits were fed a standard diet (SD) or high-fat and carbohydrate diet (HFCD) before mating and during gestation. Core body temperature and gross locomotor activity were continuously recorded in newborn rabbits, daily measurements of body weight and the amount of milk ingested was carried out. At the end of lactation, tissue samples, including brown adipose tissue (BAT) and white adipose tissue (WAT), were obtained for determining the expression of uncoupling protein-1 (UCP1) and cell death-inducing DNA fragmentation factor-like effector A (CIDEA) genes. HFCD pups exhibited conspicuous differences in the development of the daily rhythm of temperature and locomotor activity compared to the SD pups, including a significant increase in the daily mean core temperature, changes in the time when temperature or activity remains above the average, shifts in the acrophase, decrease in the duration and intensity of the anticipatory rise previous to nursing, and changes in frequency of the rhythms. HFCD pups exhibited a significant increase in BAT thermogenesis markers, and a decrease of these markers in WAT, indicating more heat generation by brown adipocytes and alterations in the browning process. These results indicate that maternal over-nutrition alters offspring homeostatic and chronostatic regulation at the physiological and behavioral levels. Further studies are needed to determine whether these alterations are associated with the changes in the organization of the circadian system of the progeny.


Assuntos
Regulação da Temperatura Corporal/fisiologia , Ritmo Circadiano/fisiologia , Lactação/fisiologia , Locomoção/fisiologia , Tecido Adiposo Marrom/fisiopatologia , Tecido Adiposo Branco/fisiopatologia , Animais , Proteínas Reguladoras de Apoptose/genética , Regulação da Temperatura Corporal/genética , Ritmo Circadiano/genética , Modelos Animais de Doenças , Feminino , Expressão Gênica , Lactação/genética , Locomoção/genética , Fenômenos Fisiológicos da Nutrição Materna , Hipernutrição/complicações , Hipernutrição/genética , Hipernutrição/fisiopatologia , Gravidez , Complicações na Gravidez/genética , Complicações na Gravidez/fisiopatologia , Coelhos , Proteína Desacopladora 1/genética
20.
Anim Genet ; 51(4): 511-520, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32363588

RESUMO

Heat stress negatively impacts the reproductive performance of dairy cows. The main objective of this study was to dissect the genetic basis underlying dairy cow fertility under heat stress conditions. Our first goal was to estimate genetic components of cow conception across lactations considering heat stress. Our second goal was to reveal individual genes and functional gene-sets that explain a cow's ability to conceive under thermal stress. Data consisted of 74 221 insemination records on 13 704 Holstein cows. Multitrait linear repeatability test-day models with random regressions on a function of temperature-humidity index values were used for the analyses. Heritability estimates for cow conception under heat stress were around 2-3%, whereas genetic correlations between general and thermotolerance additive genetic effects were negative and ranged between -0.35 and -0.82, indicating an unfavorable relationship between cows' ability to conceive under thermo-neutral vs. thermo-stress conditions. Whole-genome scans identified at least six genomic regions on BTA1, BTA10, BTA11, BTA17, BTA21 and BTA23 associated with conception under thermal stress. These regions harbor candidate genes such as BRWD1, EXD2, ADAM20, EPAS1, TAOK3, and NOS1, which are directly implicated in reproductive functions and cellular response to heat stress. The gene-set enrichment analysis revealed functional terms related to fertilization, developmental biology, heat shock proteins and oxidative stress, among others. Overall, our findings contribute to a better understanding of the genetics underlying the reproductive performance of dairy cattle under heat stress conditions and point out novel genomic strategies for improving thermotolerance and fertility via marker-assisted breeding.


Assuntos
Bovinos/fisiologia , Fertilidade/genética , Lactação/fisiologia , Reprodução/genética , Animais , Bovinos/genética , Indústria de Laticínios , Feminino , Fertilização/genética , Resposta ao Choque Térmico
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