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1.
Schweiz Arch Tierheilkd ; 163(6): 411-418, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34097635

RESUMO

INTRODUCTION: This study was aimed to determine the effect of advanced pregnancy on the topography and size of the omasum in 22 healthy Murrah buffaloes. The omasum was scanned 15-20 days before and after parturition, as per the standard procedure. The dorsal and ventral margins of the omasum were identified and marked at each intercostal space (ICS). The dorsal and ventral limits up to the dorsal midline were measured. The omasum was scanned in 6th to 11th ICS during advanced pregnancy and 7th to 11th ICS after the parturition. Irrespective of the pregnancy, the dorsal and ventral margins of the omasum were located farther dorsal and close to the spine in the 6th, 7th and 11th ICS. Except in one buffalo, the omasum was scanned in four consecutive ICS during the advanced pregnancy. After parturition the omasum was scanned in four and five consecutive ICS in 17 and five buffaloes, respectively. The mean dorsal and ventral limits of the omasum increased significantly (P .


Assuntos
Búfalos/anatomia & histologia , Búfalos/fisiologia , Lactação/fisiologia , Omaso/diagnóstico por imagem , Ultrassonografia/veterinária , Animais , Feminino , Parto/fisiologia , Gravidez
2.
J Dairy Sci ; 104(5): 5319-5331, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33663832

RESUMO

Eight lactating cows were fed 4 diets in which dietary crude protein (CP) was increased in steps of approximately 2 percentage units from 11 to 17% of DM by replacing high-moisture corn with soybean meal supplemented with rumen-protected Met to maintain a Lys:Met ratio of 3:1 in metabolizable protein. Trial design was a replicated 4 × 4 Latin square; experimental periods lasted 28 d, with data and sample collection being performed during wk 3 and 4 of each period. Digesta samples were collected from the rumen as well as the omasum to measure metabolite concentrations and ruminal outflow of N fractions using infusion of 15N-enriched ammonia to quantify microbial nonammonia N (NAN) and nonmicrobial NAN. Data were analyzed using the MIXED procedure of SAS (SAS Institute Inc.). There were linear increases in the yields of milk and true protein and concentration of milk urea N, and a linear decrease in N efficiency, with increasing dietary CP. Apparent ruminal and total-tract N digestibility increased linearly with increasing dietary CP, but estimated true total-tract N digestibility was not affected. Apparent digestibility of the other macronutrients was not influenced by diet. Ruminal ammonia, total AA and peptides, and branched-chain VFA also increased linearly with dietary CP. The 15N enrichment of liquid- and particle-associated microbes linearly declined with increasing dietary CP due to decreasing 15N enrichment of the ammonia pool. Although no effect of dietary CP on nonmicrobial NAN flow was detected, total NAN flow increased linearly from 525 g/d at 11% CP to 637 g/d at 17% CP due to the linear increase in microbial NAN flow from 406 g/d at 11% CP to 482 g/d at 17% CP. Under the conditions of this study, when dietary CP was increased by adding soybean meal supplemented with rumen-protected Met, improved milk and protein yields were driven not by RUP supply but by increased ruminal outflow of microbial protein.


Assuntos
Lisina , Omaso , Animais , Bovinos , Dieta/veterinária , Proteínas na Dieta , Digestão , Feminino , Lactação , Metionina , Leite , Nitrogênio , Rúmen
3.
Trop Anim Health Prod ; 53(2): 201, 2021 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-33687567

RESUMO

This study aimed to evaluate the effects of different traditional or alternative energy and protein sources, associated or not, on feeding behavior, ruminal kinetics, and post-ruminal flow of nutrients. Besides, it was assessed diets' effects on different sites (reticulum and omasum) of buffaloes. Four ruminally cannulated male Murrah buffaloes (average initial weight of 637 ± 66.37 kg) were randomly distributed in a 4 × 4 Latin square design. Treatments were arranged as 2 × 2 factorial arrangement. The first factor evaluated was the inclusion of energy sources (ground corn and crude glycerin), and the second factor was the inclusion of protein sources (soybean meal and cottonseed cake). Buffaloes fed cottonseed cake had a higher content of neutral detergent fiber (NDF) and potentially digestible detergent fiber (pdNDF) in the rumen environment than buffaloes fed soybean meal. There was a sampling site effect on rumen digestion rates of pdNDF, passage rates of indigestible neutral detergent fiber (iNDF), and pdNDF, and flow of iNDF. In this study, omasal collections were more representative. Total replacement of ground corn by crude glycerin promoted less NDF ruminal digestibility, and care should be taken to include this energy source. The cottonseed cake does not cause a difference in rumen dynamics and can totally replace soybean meal in feedlot buffaloes' diet.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Búfalos/metabolismo , Dieta/veterinária , Proteínas na Dieta/administração & dosagem , Omaso/química , Rúmen/metabolismo , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , Animais , Fibras na Dieta/metabolismo , Proteínas na Dieta/farmacologia , Digestão , Glicerol , Gossypium , Masculino , Omaso/efeitos dos fármacos , Omaso/metabolismo , Rúmen/química , Rúmen/efeitos dos fármacos , Proteínas de Soja , Zea mays
4.
J Dairy Sci ; 103(12): 11332-11348, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33069418

RESUMO

The objective of this study was to evaluate the effect of rolled barley grain (RB) supplementation on rumen metabolism, omasal flow of nutrients, and microbial dynamics in lactating dairy cows fed fresh perennial ryegrass (Lolium perenne L.; PRG)-based diets. Ten ruminally cannulated Holstein cows averaging (mean ± standard deviation) 49 ± 23 d in milk and 513 ± 36 kg of body weight were assigned to 1 of 2 treatments in a switchback design. The treatment diets were PRG only (G) or PRG plus 3.5 kg of dry matter RB (G+RB). The study consisted of three 29-d periods where each period consisted of 21 d of diet adaptation and 8 d of data and sample collection. A double marker system was used to quantify nutrient flow entering the omasal canal along with labeled 15N-ammonium sulfate to measure bacterial, protozoal, and nonmicrobial N flow. Rumen evacuation techniques were used to determine nutrient and microbial pool size, allowing the calculation of fractional rates of digestion and microbial growth. There was no difference in daily milk yield or energy-corrected milk yield between treatments. Milk fat concentration and milk urea N decreased, whereas milk protein concentration increased in cows fed the G+RB diet. During the omasal sampling phase, dry matter intake was higher in cows fed the G+RB diet. Ruminal and total-tract neutral detergent fiber digestibility was lower in G+RB cows; however, no difference was observed in reticulorumen pH. The rumen pool size of fermentable carbohydrate was increased in cows fed the G+RB diet; however, the fractional rate of digestion was decreased. Flow of nonammonia N and bacterial N at the omasal canal increased in cows fed the G+RB diet compared with the G diet. Protozoa N flow was not different between diets; however, protozoa appeared to supply a much larger amount of microbial N and exhibited shorter generation time than previously considered. Feed N ruminal digestibility, corrected for microbial contribution, was similar for both treatments (88.4 and 89.0% for G and G+RB, respectively). In conclusion, RB supplementation did not benefit overall animal performance; however, it reduced ruminal neutral detergent fiber digestibility and increased bacterial N flow. The results demonstrate the large dependence of cows consuming PRG-based diets on microbial N as the main source of nonammonia N supply. Additional quantitative research is required to further describe the supply of nutrients and microbial dynamics in cows consuming PRG-based diets in an effort to determine most limiting nutrients.


Assuntos
Bovinos/fisiologia , Suplementos Nutricionais/análise , Hordeum , Lolium , Leite/metabolismo , Animais , Peso Corporal , Bovinos/microbiologia , Dieta/veterinária , Fibras na Dieta/metabolismo , Digestão , Grão Comestível , Feminino , Fermentação , Lactação , Leite/química , Nutrientes/metabolismo , Omaso/metabolismo , Rúmen/metabolismo , Rúmen/microbiologia , Ureia/metabolismo
5.
In Vitro Cell Dev Biol Anim ; 56(7): 495-499, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32839903

RESUMO

The establishment and culture of bovine omasal epithelial cells (BOECs) in vitro is a valuable tool for the study of the physiological function, nutrient absorption, and transport mechanisms of the omasum in dairy cows. This paper proposes a method for the culture of primary BOECs. Trypsin digestion was used to subculture the BOECs, which were passaged for 20 generations in vitro, and showed typical epithelial-like characteristics and a cobblestone morphology. The primary BOECs had a fast growth phase (between days 4 and 5) and were validated by their slight ß-galactosidase and visible cytokerat in 18 expression. In addition, RT-PCR results demonstrated that the monocarboxylate transporter 1 (MCT1), Na+/H+exchanger 1 (NHE1), and Na+/H+ exchanger 3 (NHE3) were expressed in the isolated primary BOECs. In conclusion, this primary BOEC isolation and culture model is a promising method for the study of nutrient absorption and regulation, as well as the immune regulation of epithelial cell transport in vitro.


Assuntos
Células Epiteliais/citologia , Omaso/citologia , Animais , Bovinos , Proliferação de Células , Forma Celular , Células Cultivadas , Senescência Celular , Células Epiteliais/metabolismo , Queratina-18/metabolismo
6.
J Dairy Sci ; 103(3): 2347-2362, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31954580

RESUMO

Although the omasal sampling technique (OST) has been successfully used to estimate ruminal fermentation and nutrient flow, alternatives to invasive animal trials should be pursued and evaluated. The objective of this study was to evaluate carbohydrate and N metabolisms using a meta-analytical approach to compare 2 methods: dual-flow continuous culture system (DFCCS) and OST. To be included, studies needed to report diet chemical composition and report at least 1 of the dependent variables of interest. A total of 155 articles were included, in which 97 used the DFCCS and 58 used the OST. The independent variables used were dietary nonfiber carbohydrate concentration, neutral detergent fiber (NDF) degradability, true crude protein (CP) degradability, and efficiency of microbial protein synthesis (EMPS). In addition, 12 dependent variables were used. Statistical analyses were performed using the Mixed procedure of SAS (SAS Institute Inc., Cary, NC). A random coefficients model was used considering study as a random effect and including the possibility of covariance between the slope and the intercept. The effect of method (DFCCS or OST) was included and tested in the estimates of the intercept, linear, and quadratic effects of the independent variable. There was no method effect when NDF degradability was regressed with total volatile fatty acids concentration, true CP degradability, and EMPS. Molar proportions of acetate and propionate were quadratically associated with NDF degradability. When NDF degradability was regressed with acetate and propionate there was a method effect, differing only in the intercept (ß0) estimate. True organic matter digestibility, bacterial N/total N, efficiency of N utilization, total volatile fatty acid concentration, and molar proportion of butyrate linearly increased as dietary nonfiber carbohydrate concentration increased, and none of these variables were affected by method. Concentration of ammonia N had a linear and positive association with true CP degradability. This was the only variable that had a method effect when regressed with true CP degradability, differing only in the estimate of the intercept (ß0). As EMPS increased, efficiency of N utilization also increased, and it was affected by method. Overall, the majority of DFCCS responses were similar to OST. When a method effect was observed, it was mainly on the estimate of the intercept, demonstrating that the magnitude of these responses was different. However, the relationships between independent and dependent variables were similar across methods.


Assuntos
Metabolismo dos Carboidratos , Bovinos/metabolismo , Fibras na Dieta/metabolismo , Nitrogênio/metabolismo , Ração Animal/análise , Animais , Técnicas de Cultura , Dieta/veterinária , Digestão , Ácidos Graxos Voláteis/metabolismo , Feminino , Fermentação , Omaso/metabolismo , Omaso/microbiologia , Rúmen/metabolismo , Rúmen/microbiologia
7.
Meat Sci ; 160: 107962, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31683256

RESUMO

Two studies were carried out, the first with the objective to evaluate performance, beef quality and expression of genes involved in lipid metabolism in the muscle of bulls fed with or without low-fat dried distillers grains with solubles (DDGS, 21% DM) in the diet. In the second, eight rumen-fistulated bulls were assigned in a switch back design to evaluate the fatty acid profile of omasal fluid. We hypothesized that bulls fed DDGS may have an improved fatty acid profile and expression of genes involved in lipid metabolism may be altered, without affecting performance. Bulls fed DDGS had greater (P < .05) concentrations of PUFA n-6 in the omasum and muscle. CLA t10, c12 content was higher and there was lower expression of the LPL gene (P = .05) in the muscle of animals fed DDGS (P = .03). In conclusion, DDGS can be used as a protein feedstuff because it maintains beef quality.


Assuntos
Bovinos/fisiologia , Dieta/veterinária , Carne Vermelha/análise , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Grão Comestível , Ácidos Graxos/metabolismo , Expressão Gênica , Lipogênese/genética , Masculino , Omaso/química
8.
J Dairy Sci ; 102(7): 6088-6108, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31056327

RESUMO

The objective of this study was to determine whether the partial replacement of barley starch with lactose (fed as dried whey permeate; DWP) affects N utilization, whole-body urea kinetics, and production in dairy cows. Eight lactating Holstein cows were used in a replicated 4 × 4 Latin square design with 28-d periods. Four cows in one Latin square were ruminally cannulated and used to determine dietary effects on whole-body urea kinetics and N utilization. Cows were fed a barley-based diet that contained 3.6% (dry matter basis) total sugar (TSG; designated control), or diets that contained 6.6, 9.6, or 12.6% TSG. Dietary TSG content was increased by the replacement of barley grain with DWP (83% lactose). Diets were isonitrogenous (∼17.3% crude protein), and starch contents of the control, 6.6, 9.6, and 12.6% TSG diets were 24.3, 22.2, 21.2, and 19.1%, respectively. Whole-body urea kinetics were measured using 4-d infusions of [15N15N]-urea with concurrent total collections of feces and urine. Dry matter intake (mean = 26.7 kg/d), milk yield (mean = 34.9 kg/d), and milk protein and fat contents were unaffected by diet. Ruminal ammonia-N concentration decreased linearly as TSG content increased, whereas ruminal butyrate concentration increased linearly as TSG content increased. Urinary excretion of total N and urea-N changed quadratically, whereas urinary excretion of total N (% of N intake) tended to change quadratically as TSG content increased. Fecal N excretion linearly increased as TSG content increased. A quadratic response was observed for total N excretion as TSG content increased. Milk N and retained N were not affected by diet. As TSG content increased, we observed quadratic responses in the omasal flow of fluid-associated and total bacterial nonammonia N, endogenous production of urea-N, urea-N recycled to the gastrointestinal tract, and urea-N returned to the ornithine cycle. Dietary TSG content did not affect the anabolic utilization of recycled urea-N or the proportion of recycled urea-N that was used for bacterial growth. Our results indicate that feeding DWP did not influence dry matter intake, milk yield, or milk composition. Feeding DWP decreased ruminal ammonia-N concentration, but this did not result in positive responses in milk protein secretion or N balance. The quadratic response in omasal flow of total bacterial nonammonia N indicated that including TSG beyond 9.6% of diet dry matter might depress ruminal microbial protein synthesis.


Assuntos
Ração Animal , Bovinos/metabolismo , Hordeum , Lactose/administração & dosagem , Nitrogênio/metabolismo , Omaso/metabolismo , Ureia/metabolismo , Amônia/metabolismo , Ração Animal/análise , Animais , Nitrogênio da Ureia Sanguínea , Indústria de Laticínios , Dieta/veterinária , Feminino , Lactação , Lactose/metabolismo , Leite , Proteínas do Leite/metabolismo , Nutrientes/metabolismo , Amido/administração & dosagem , Amido/metabolismo
9.
Arch Anim Nutr ; 73(3): 171-193, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31033355

RESUMO

This study was designed to determine the rumen outflow of fatty acids (FA) and biohydrogenation (BH) extent using alternative sampling sites (reticulum and omasum) to abomasum in dry cows fed different sources of FA. Four Holstein non-pregnant dry cows (≥3 parturitions, and 712 ± 125 kg BW), cannulated in the rumen and abomasum, were randomly assigned to a 4 × 4 Latin square design experiment, containing the following treatments: 1) control (CON); 2) soya bean oil (SO), dietary inclusion at 30 g/kg; 3) whole raw soya beans (WS), dietary inclusion at 160 g/kg; and 4) calcium salts of FA (CSFA), dietary inclusion at 32 g/kg. Rumen outflow of nutrients was estimated using the three markers reconstitution system (cobalt-EDTA, ytterbium chloride, and indigestible neutral detergent fibre [NDF]). Diets with FA sources decreased feed intake and increased FA intake. No differences in nutrient intake and digestibility were detected among cows fed diets supplemented with different FA sources. Diets with FA sources reduced the rumen outflow of DM and NDF, hence decreasing their passage rates. In addition, SO diet reduced the ruminal outflow of DM and NDF in comparison with WS and CSFA. Omasal sampling yielded the highest values of rumen outflow of NDF and potentially degradable NDF (pdNDF), whereas the reticular and abomasal samplings yielded intermediate and least values, respectively. The interaction effect between diet and sampling site was observed for rumen outflow of majority FA (except for C16:0, C18:0, and C18:2 trans-10, cis-12) and BH extension of C18:1 cis, C18:2, and C18:3. Calculations derived from abomasal sampling revealed that WS and CSFA diets had lower BH extent of C18:1 cis and C18:2 in comparison with SO, whereas cows fed CSFA had greater BH extent of C18:3 and lower BH extent of C18:1 cis compared to those fed WS. However, the latter results were not similar when calculations were performed based on the reticular and omasal samplings. Thus, there is evidence that neither reticular nor omasal samplings are suitable for estimating rumen outflow of FA in dry cows. In addition, WS and CSFA diets can increase the abomasal flow of polyunsaturated FA in dry cows.


Assuntos
Abomaso/fisiologia , Criação de Animais Domésticos/métodos , Digestão/fisiologia , Ácidos Graxos/fisiologia , Ácido Linoleico/metabolismo , Retículo/fisiologia , Rúmen/fisiologia , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bovinos , Dieta/veterinária , Suplementos Nutricionais/análise , Feminino , Lactação , Ácido Linoleico/administração & dosagem , Omaso/fisiologia , Distribuição Aleatória , Óleo de Soja/administração & dosagem , Óleo de Soja/metabolismo , Soja
10.
J Dairy Sci ; 102(6): 5148-5160, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30904304

RESUMO

Diet-induced milk fat depression (MFD) in lactating cows has been attributed to alterations in ruminal lipid metabolism leading to the formation of specific fatty acid (FA) biohydrogenation intermediates that directly inhibit milk fat synthesis. However, the mechanisms responsible for decreased lipid synthesis in the mammary gland over time are not well defined. The aim of this study was to evaluate the effect of diet on milk FA composition and milk fat production over time, especially during MFD, and explore the associations between MFD and FA biohydrogenation intermediates in omasal digesta and milk. Four lactating Finnish Ayrshire cows used in a 4 × 4 Latin square with a 2 × 2 factorial arrangement of treatments and 35-d experimental periods were fed diets formulated to cause differences in ruminal and mammary lipid metabolism. Treatments consisted of an iso-nitrogenous total mixed ration based on grass silage with a forage to concentrate ratio of 65:35 or 35:65 without added oil, or with sunflower oil at 50 g/kg of diet dry matter. The high-concentrate diet with sunflower oil (HSO) induced a 2-stage drop in milk fat synthesis that was accompanied by specific temporal changes in the milk FA composition. The MFD on HSO was associated especially with trans-10 18:1 and also with trans-9,cis-11 conjugated linoleic acid (CLA) in milk and omasal digesta across all diets and was accompanied by the appearance of trans-10,cis-15 18:2. Trans-10,cis-12 CLA was increased in HSO, but milk fat secretion was not associated with omasal or milk trans-10,cis-12 CLA. The temporal changes in milk fat content and yield and milk FA composition reflect the shift from the predominant ruminal biohydrogenation pathway to an alternative pathway. The ambiguous role of trans-10,cis-12 CLA suggests that trans-10 18:1, trans-9,cis-11 CLA and trans-10,cis-15 18:2 or additional mechanisms contributed to the diet-induced MFD in lactating cows.


Assuntos
Bovinos/metabolismo , Dieta/veterinária , Ácidos Graxos/metabolismo , Leite/metabolismo , Animais , Feminino , Hidrogenação , Lactação , Ácidos Linoleicos Conjugados/farmacologia , Metabolismo dos Lipídeos , Leite/química , Omaso/metabolismo , Poaceae , Silagem , Óleo de Girassol
11.
J Dairy Sci ; 102(4): 3023-3035, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30799114

RESUMO

The objective of this study was to evaluate the effects of a fermentation byproduct on rumen fermentation and microbial yield in high producing lactating dairy cattle. Eight ruminally cannulated multiparous Holstein cows averaging (mean ± standard deviation) 60 ± 10 d in milk and 637 ± 38 kg of body weight were assigned to 1 of 2 treatment sequences in a switchback design. Treatment diets contained (dry matter basis) 44% corn silage, 13% alfalfa silage, 12% ground corn, and 31% premix containing either a control mix of urea and wheat middlings (CON) or a commercial fermentation byproduct meal (Fermenten, Arm and Hammer Animal Nutrition, Princeton, NJ) at 3% diet inclusion rate (EXP). Diets were formulated to be isonitrogenous and isocaloric, with similar levels of neutral detergent fiber and starch. The trial consisted of three 28-d experimental periods, where each period consisted of 21 d of diet adaptation and 7 d of data and sample collection. Omasal nutrient flows were determined using a triple-marker technique and double-labeled 15N15N-urea. The EXP diet provided 18 g/d more nonammonia N versus the CON diet, representing 3.0% of total N intake. Energy-corrected milk yield (41.7 and 43.1 kg/d for CON and EXP, respectively), milk fat, and protein yield and content did not differ between treatments. Total dry matter intake was similar between treatments (25.5 and 26.4 kg/d for CON and EXP, respectively). Ammonia N concentration and pool size in the rumen was greater in cows fed the EXP diet. No differences were observed in rumen or total-tract dry matter, organic matter, or neutral detergent fiber digestibility. Ruminal degradation of feed N was 15% lower in cows fed EXP diets, resulting in differences in omasal N flows. Results demonstrated the fermentation byproduct meal had a sparing effect on degradable feed protein, but did not increase microbial N flow from the rumen.


Assuntos
Dieta/veterinária , Lactação , Leite , Omaso/metabolismo , Rúmen/metabolismo , Ruminação Digestiva , Ureia/farmacologia , Amônia/metabolismo , Ração Animal , Animais , Peso Corporal , Bovinos , Fibras na Dieta/metabolismo , Feminino , Fermentação , Medicago sativa , Nutrientes , Silagem , Amido/metabolismo , Zea mays
12.
Arq. bras. med. vet. zootec. (Online) ; 71(1): 340-344, jan.-fev. 2019. tab
Artigo em Português | ID: biblio-1038588

RESUMO

The morphology of the ruminal and omasal mucosa and hepatic parenchyma of 44 young bulls submitted to four types of concentrates were evaluated by varying the inclusion level of crude Glycerin - CG (0, 6, 12 and 18%). The variables evaluated were number of ruminal papillae per cm² of wall; area of the papillae and total absorption surface per cm² of wall; Mitotic index - MI, height and area of ruminal and omasal papillae; and hepatic morphology. The samples processed for inclusion in paraffin and stained with Hematoxylin-Eosin. The different levels of inclusion of CG in the diet did not interfere either in the number of papillae per cm2 of rumen wall (P= 0,70) or in the ruminal absorptive surface area (P= 0,89). Animals that received diets with levels 12 and 18% had higher MI of the ruminal epithelium (P< 0.01), but higher cell proliferation wasn't reflected in height gain and papillary area (P= 0,82). The omasal mucosa wasn't influenced by the inclusion of CG (MI e height gain and papillary area, P= 0,43, P= 0,56 e P= 0,9, respectively). The inclusion of GB in up to 18% of diet dry matter didn't alter the morphology of the rumen and omaso mucosa; and the integrity hepatic parenchyma.(AU)


Assuntos
Animais , Bovinos , Omaso/anatomia & histologia , Rúmen/anatomia & histologia , Ruminantes/anatomia & histologia , Glicerol/administração & dosagem , Fígado/anatomia & histologia
13.
J Morphol ; 280(2): 259-277, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30615226

RESUMO

The omasum is the third forestomach compartment of pecoran ruminants. It is assumed that the re-absorption of fluid present in the forestomach digesta (that facilitates particle sorting, digestion, and harvest of microbes) is its main function, so that less diluted digesta is submitted to enzymatic digestion in the lower digestive tract. Here, we evaluate measures of omasum size (representing 84 ruminant species in the largest data set) against body mass and proxies of the natural diet (%grass) or forestomach physiology (fluid throughput), using phylogenetically controlled models. The origin of specimens (free-ranging or captive) did not have an effect in the data set. Models with the best support invariably either included %grass or a physiology proxy in addition to body mass. These effects were not necessarily additive (affecting the intercept of the allometric regression), but often indicated a change in the allometric body mass-exponent with diet or physiology. Only models that allowed an influence on the allometric exponent yielded basic exponents compatible with predictions derived from geometry. Species that include more grass in their natural diet, or that have a "cattle-type" physiology marked by a high forestomach fluid throughput, generally have larger omasa. However, the existence of outliers, as well as the overall data pattern, suggest that this is not an obligatory morphophysiological condition. Circumstantial evidence is presented leading to the hypothesis that the comparatively small and less complex omasa of "moose-type" species do not necessarily represent an "original" state, but may be derived from more complex states by ontogenetic reduction and fusion of omasal laminae.


Assuntos
Tamanho Corporal , Dieta , Fenômenos Fisiológicos do Sistema Digestório , Omaso/anatomia & histologia , Ruminantes/anatomia & histologia , Animais , Animais de Zoológico/anatomia & histologia , Peso Corporal , Trato Gastrointestinal/anatomia & histologia , Análise dos Mínimos Quadrados , Filogenia
14.
J Dairy Sci ; 102(4): 3036-3052, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30660423

RESUMO

The objective of this study was to evaluate the effect of a fermentation by-product on rumen function, microbial yield, and composition and flows of nutrients from the rumen in high-producing lactating dairy cattle. Eight ruminally cannulated multiparous Holstein cows averaging (mean ± standard deviation) 60 ± 10 d in milk and 637 ± 38 kg of body weight were randomly assigned to 1 of 2 treatment sequences in a switchback design. Treatment diets contained (dry matter basis) 44% corn silage, 13% alfalfa silage, 12% ground corn, and 31% protein premix, containing either a control mix of urea and wheat middlings (CON) or a commercial fermentation by-product meal (Fermenten, Arm and Hammer Animal Nutrition, Princeton, NJ) at 3% diet inclusion rate (EXP). The trial consisted of three 28-d experimental periods, where each period consisted of 21 d of diet adaptation and 7 d of data and sample collection. A triple-marker technique and double-labeled 15N15N-urea were used to were used to measure protozoal, bacterial, and nonmicrobial omasal flow of AA. Rumen pool sizes and omasal flows were used to determine digestion parameters, including fractional rates of carbohydrate digestion, microbial growth, and yield of microbial biomass per gram of degraded substrate. Fermentation by-product inclusion in EXP diets increased microbial N and amino acid N content in microbes relative to microbes from CON cows fed the urea control. Microbial AA profile did not differ between diets. Daily omasal flows of AA were increased in EXP cows as a result of decreased degradation of feed protein. The inclusion of the fermentation by-product increased nonmicrobial AA flow in cows fed EXP versus CON. Average protozoal contribution to microbial N flow was 16.8%, yet protozoa accounted for 21% of the microbial AA flow, with a range of 8 to 46% for individual AA. Cows in this study maintained an average rumen pool size of 320 g of microbial N, and bacterial and protozoal pools were estimated at 4 different theoretical levels of selective protozoa retention. Fractional growth rate of all microbes was estimated to be 0.069 h-1, with a yield of 0.44 g of microbial biomass per gram of carbohydrate degraded. Results indicated that fermentation by-product can increase omasal flow of AA while maintaining adequate rumen N available for microbial growth and protein synthesis. Simulations from a developmental version of the Cornell Net Carbohydrate and Protein System indicated strong agreement between predicted and observed values, with some areas key for improvement in AA flow and bacterial versus protozoal N partitioning.


Assuntos
Aminoácidos/metabolismo , Bovinos/metabolismo , Dieta/veterinária , Fermentação , Nitrogênio/metabolismo , Omaso/metabolismo , Ruminação Digestiva , Animais , Bactérias/metabolismo , Feminino , Cinética , Lactação , Medicago sativa , Leite , Distribuição Aleatória , Rúmen , Silagem , Ureia/metabolismo , Zea mays
15.
J Sci Food Agric ; 99(1): 100-108, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-29797328

RESUMO

BACKGROUND: Peptide absorption from the forestomach plays a vital role in protein nutrition of dairy cows. This study was conducted to investigate the mechanism of dipeptide absorption in the forestomach of dairy cows using isolated omasal epithelial cells (OECs) and ruminal epithelial cells (RECs). RESULTS: Compared with RECs, the OECs formed a less tight monolayer, but had greater ability to transport glycylsarcosine (Gly-Sar) (P < 0.05). The OEC monolayers were immunopositive for the antibodies of anti-junction proteins. Gly-Sar transport was significantly greater at 37 °C than that at 4 °C, with an optimal pH of 6.0-6.5, and was decreased significantly by diethylpyrocarbonate and dipeptide Met-Gly (P < 0.05). The apical-to-basolateral transport was significantly greater than basolateral-to-apical transport (P < 0.05). Knockdown of peptide transporter 1 (PepT1) resulted in less Gly-Sar uptake in OECs, whereas overexpression of PepT1 in OECs resulted in higher Gly-Sar uptake (P < 0.05). Additionally, the expression of PepT1 was upregulated by the treatment with various dipeptides (P < 0.05). CONCLUSION: The OECs have a greater ability to transport Gly-Sar than RECs do. Both passive and active routes are involved in the process of Gly-Sar absorption in the isolated cultured forestomach epithelial cells from dairy cows. © 2018 Society of Chemical Industry.


Assuntos
Bovinos/metabolismo , Dipeptídeos/metabolismo , Células Epiteliais/metabolismo , Omaso/citologia , Rúmen/citologia , Animais , Transporte Biológico , Células Cultivadas , Células Epiteliais/química , Concentração de Íons de Hidrogênio , Omaso/química , Omaso/metabolismo , Rúmen/química , Rúmen/metabolismo
16.
J Anim Sci ; 96(12): 5311-5324, 2018 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-30295810

RESUMO

The aim of this study was to determine the effect of exogenous butyrate on the structure and selected functions of the stomach in sheep. Eighteen rams (30.8 ± 2.1 kg; 12 to 15 mo of age) were allocated to the study and fed a diet for 14 d without (CTRL) or with sodium butyrate (BUT; 36 g/kg of offered DM). Neither DMI nor initial BW differed between treatments (P ≥ 0.61), but final BW was greater for BUT compared with CTRL (P = 0.03). Butyrate concentration in the reticuloruminal fluid and abomasal digesta was greater for BUT compared with CTRL (P ≤ 0.01), but total short-chain fatty acids (SCFA) concentration, as well as concentration of other SCFA, did not differ between treatments (P ≥ 0.07). Relative to BW, reticuloruminal tissue mass tended (P = 0.09) to be greater and omasal digesta was less (P = 0.02) for BUT compared with CTRL. Dietary butyrate did not affect ruminal papillae length, width, and density nor did it affect ruminal epithelium thickness (P ≥ 0.12) in the ventral sac of the rumen. However, the DM of ruminal epithelium (mg/cm2) tended (P = 0.06) to be greater for BUT compared with CTRL. Omasal and abomasal epithelium thicknesses were greater (P ≤ 0.05) for BUT compared with CTRL. Mitosis-to-apoptosis ratio in the abomasal epithelium was less for BUT compared with CTRL (P = 0.04). Finally, the mRNA expression of peptide transporter 1 in the omasal epithelium was less (P = 0.02) and mRNA expression of monocarboxylate transporter 1 in the abomasal epithelium tended (P = 0.07) to be greater for BUT compared with CTRL. It can be concluded that exogenous butyrate supplementation affected not only the rumen but also omasum and abomasum in sheep.


Assuntos
Ração Animal/análise , Ácido Butírico/farmacologia , Ovinos/fisiologia , Abomaso/efeitos dos fármacos , Abomaso/metabolismo , Animais , Dieta/veterinária , Epitélio/efeitos dos fármacos , Epitélio/metabolismo , Ácidos Graxos Voláteis/análise , Trato Gastrointestinal/metabolismo , Masculino , Omaso/efeitos dos fármacos , Omaso/metabolismo , Rúmen/efeitos dos fármacos , Rúmen/metabolismo
17.
J Microbiol ; 56(10): 734-743, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30136259

RESUMO

The ruminant digestive system harbors a complex gut microbiome, which is poorly understood in the case of the four stomach compartments of yak. High-throughput sequencing and quantitative PCR were used to analyse microbial communities in the rumen, reticulum, omasum, and abomasum of six domesticated yak. The diversity of prokaryotes was higher in reticulum and omasum than in rumen and abomasum. Bacteroidetes predominated in the four stomach compartments, with abundance gradually decreasing in the trend rumen > reticulum > omasum > abomasum. Microorganism composition was different among the four compartments, all of which contained high levels of bacteria, methanogens, protozoa and anaerobic fungi. Some prokaryotic genera were associated with volatile fatty acids and pH. This study provides the first insights into the microorganism composition of four stomach compartments in yak, and may provide a foundation for future studies in this area.


Assuntos
Ração Animal , Bactérias/classificação , Bovinos/microbiologia , Gorduras/administração & dosagem , Microbioma Gastrointestinal , Abomaso/microbiologia , Agricultura , Animais , Bactérias/genética , Bactérias/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala , Masculino , Omaso/microbiologia , Rúmen/microbiologia , Estômago de Ruminante/microbiologia
18.
J Anim Sci ; 96(8): 3420-3432, 2018 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-29788095

RESUMO

Teff (Eragrostis tef cv. Moxie), a warm-season annual grass, could be an excellent forage for beef cattle. However, there is limited information on its nutritive value to cattle when harvested at different stages of maturity. Thus, the objective of this research was to determine the effect of feeding teff hay harvested at the boot (BT), early-heading (EH), or late-heading (LH) stages of maturity on nutrient intake, ruminal fermentation characteristics, omasal nutrient flow, and N utilization in beef cattle. Six ruminally cannulated beef heifers (mean initial BW ± SD, 476 ± 32.6) were used in a replicated 3 × 3 Latin square design with 28-d periods (18 d for adaptation and 10 d for measurements). Dry matter intake was measured daily. Indwelling pH loggers were used to measure ruminal pH from days 21 to 28. Ruminal fluid and omasal digesta were collected from days 26 to 28 to determine fermentation characteristics and omasal nutrient flow. Fecal and urine samples to quantify N excretion were also collected (days 26 to 28). Blood samples for plasma urea-N (PUN) determination were collected 3 h post-feeding on day 28. There were no changes (P > 0.28) in the ADF or NDF content of teff with advancing maturity, but indigestible NDF increased (P < 0.01) with increasing maturity. Maturity had no effect (P ≥ 0.14) on DMI, and ruminal total short-chain fatty acid (SCFA) concentration, pH, digestibility, and outflow of DM, OM, NDF, ADF, and CP. However, the CP content of BT hay was greater (P < 0.01) than for EH and LH hay (18.1, 14.1, and 11.5%, respectively, DM basis), and this resulted in the higher CP intake (P < 0.01) for heifers fed the BT than the EH and LH hay. Consequently, ruminal ammonia-N (NH3-N) concentration was greater (P < 0.01) for heifers fed BT than EH and LH hay, thereby possibly explaining the tendency for a decrease (P = 0.08) in PUN concentration, and a decrease (P < 0.01) in the excretion of total N, urine N, and urea-N (UUN) with advancing maturity. However, fecal N excretion (g/d) did not differ (P = 0.76). In conclusion, despite a decrease in CP intake and ruminal NH3-N concentration, feeding beef heifers EH and LH compared to BT teff hay did not compromise ruminal digestion and outflow of DM, OM, NDF, ADF, and CP, and microbial protein synthesis. Advancing maturity in teff hay also resulted in a decrease in the excretion of total N and urine N and UUN when fed to cattle.


Assuntos
Ração Animal/análise , Bovinos/fisiologia , Suplementos Nutricionais , Ingestão de Energia , Eragrostis , Amônia/metabolismo , Animais , Digestão , Ácidos Graxos Voláteis/análise , Fezes/química , Feminino , Fermentação , Valor Nutritivo , Omaso/metabolismo , Poaceae , Rúmen/química , Rúmen/metabolismo
19.
Res Vet Sci ; 118: 324-330, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29601970

RESUMO

Transport of bicarbonate across the isolated epithelium of sheep omasum was studied in vitro in Ussing chambers in combination with the pH-Stat method. The transport of HCO3- occurred in both directions, but Jms HCO3- was significant larger than Jsm. Reducing the activity of the apical Na/H exchanger by a low mucosal Na concentration caused a significant reduction of Jms HCO3-. Mucosal amiloride or short chain fatty acids (25 mmol l-1 SCFA) numerically decreased Jms HCO3-, but their combination (amiloride + SCFA) caused a significant reduction, which was also observed after addition of the carboanhydrase inhibitor ethoxyzolamide. Concentrations of 5 or 15 mmol·l-1 mucosal ammonia did not change transport rates. The obtained results indicate the importance of an undisturbed cytosolic pH for transcellular HCO3- transport, which is probably mediated by an anion exchanger in both the apical and basolateral membranes. Possible impairment of HCO3- transport appears to be an overlooked factor in the pathogenesis of displacement of the abomasum.


Assuntos
Bicarbonatos/metabolismo , Omaso/metabolismo , Ovinos/metabolismo , Animais , Epitélio , Ácidos Graxos Voláteis , Feminino , Concentração de Íons de Hidrogênio , Masculino , Sódio
20.
J Anim Sci ; 96(1): 108-125, 2018 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-29385473

RESUMO

The objective of this study was to determine effect of ruminal acidosis (RA) and low feed intake [LFI] on the regional barrier function of the gastrointestinal tract. Twenty-one Holstein steers were fed for ad libitum intake for 5 d (control [CON]), fed at 25% of ad libitum intake for 5 d (LFI), or provided 2 d of ad libitum intake followed by 1-d of feed restriction (25% of ad libitum intake), 1 d where 30% of ad libitum dry matter intake (DMI) was provided as pelleted barley followed by the full allocation (RA) and fed for ad libitum intake the following day. Tissues and digesta from the rumen, omasum, duodenum, jejunum, ileum, cecum, proximal, and distal colon were collected. Permeability was assessed using the mucosal-to-serosal flux of inulin (JMS-inulin) and mannitol (JMS-mannitol). Digesta pH was 0.81, 0.63, and 0.42 pH units less for RA than CON in the rumen, cecum, and proximal colon; while, LFI had pH that was 0.47 and 0.36 pH units greater in the rumen and proximal colon compared to CON. Total ruminal short-chain fatty acid (SCFA) concentration were less for LFI (92 mM; P = 0.010) and RA (87 mM; P = 0.007) than CON (172 mM) steers. In the proximal colon, the proportion of butyrate (P = 0.025 and P = 0.022) and isobutyrate (P = 0.019 and P = 0.019) were greater, and acetate (P = 0.028 and P = 0.028) was less for LFI and RA, respectively, when compared to CON steers. Ruminal papillae length, width, perimeter, and surface area were 1.21 mm, 0.78 mm, 3.84 mm, and 11.15 mm2 less for LFI than CON; while, RA decreased papillae width by 0.52 mm relative to CON. The JMS-mannitol was less for LFI steers than CON in the proximal colon (P = 0.041) and in the distal colon (P = 0.015). Increased gene expression for claudin 1, occludin, tight-cell junction protein 1 and 2, and toll-like receptor 4 were detected for LFI relative to CON in the rumen, jejunum, and proximal colon. For RA steers, expression of toll-like receptor 4 in the rumen, and occludin and tight-cell junction protein 1 were greater in the jejunum than CON. An acute RA challenge decreased pH in the rumen and large intestine but did not increase tissue permeability due to increases in the expression of genes related to barrier function within 1 d of the challenge. Steers exposed to LFI for 5 d had reduced ruminal SCFA concentrations, smaller ruminal papillae dimensions, and increased tissue permeability in the proximal and distal colon despite increases for genes related to barrier function and immune function.


Assuntos
Acidose/veterinária , Doenças dos Bovinos/fisiopatologia , Ingestão de Alimentos , Acidose/fisiopatologia , Ração Animal , Animais , Bovinos , Dieta/veterinária , Ácidos Graxos Voláteis/metabolismo , Privação de Alimentos , Trato Gastrointestinal/metabolismo , Hordeum , Concentração de Íons de Hidrogênio , Intestino Grosso/metabolismo , Masculino , Omaso/metabolismo , Permeabilidade , Rúmen/fisiologia
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