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1.
Trop Anim Health Prod ; 54(2): 131, 2022 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-35260924

RESUMEN

The current trial was carried out to evaluate the impacts of adding licury cake (Syagrus coronata) in high-concentrate diets for goat kids feedlot-finished on growth performance and metabolic parameters. Forty crossbred non-castrated Boer goat kids with approximately four months and similar initial live weights (20.15 ± 2.79 kg). The experimental design used in this study was a completely randomized, with four diets (0, 10, 20, and 30% of licury cake inclusion in a dry matter basis (DM)). Licury cake inclusion decreased nutrient intake and digestibility (P < 0.05). Times spent in feeding (P < 0.001) and rumination (P = 0.003) activities, number of events in feeding (P < 0.001) and idling (P = 0.015) increased, whereas a linear reduction occurred in feeding and rumination efficiencies of DM and neutral detergent fiber (P < 0.001). Nitrogen (N) intake, retained N (P < 0.001), triglycerides concentrations (P = 0.002), aspartate-aminotransferase, alanine-aminotransferase, and gamma-glutamyltransferase decreased with the licury cake inclusion (P < 0.05). Final body weight (P = 0.008), average daily gain (P = 0.001), and total weight gain (P = 0.001) decreased linearly when licury cake was included in diets. High-concentrate diets containing increasing levels of licury cake decrease intake and apparent digestibility of nutrients and performance when supplied for goat kids feedlot-finished. Therefore, the inclusion of the studied levels of licury cake in goat kids fed high-concentrate diets is not recommended for feedlot-finished systems.


Asunto(s)
Alimentación Animal , Cabras , Alimentación Animal/análisis , Animales , Dieta/veterinaria , Digestión , Ingestión de Alimentos , Conducta Alimentaria , Cabras/metabolismo , Nitrógeno/metabolismo
2.
Trop Anim Health Prod ; 53(6): 539, 2021 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-34761279

RESUMEN

We executed two studies to investigate time to reach steady state (EXP1) and diurnal variations (EXP 2) of markers, in order to recommend spot fecal sampling in sheep. Eight lambs were used in EXP 1. Each animal has received titanium dioxide (TDOX) and chromium oxide (COX) together during two periods of 15 days. Thirty sheep of the Santa Ines breed were used in EXP 2. Fecal samples were taken with 2-h intervals in the last 5 days of each period, simultaneously to total feces collection. A sine-cosine model was used to evaluate EXP 2, and broken-line model for EXP 1. TDOX could complete its recovery after 2.3 days, and it could accurately promote fecal estimates after 3 days of marker infusion. COX could stabilize after 4.1 days, and it could promote fecal estimates after 5 days. However, estimated fecal excretion became similar to total feces output after 3 days for TDOX and after 6 days for COX. For both markers, a total 6 days of adaptation period could be summed to a 3-day collection period. Spot sampling was similar to total fecal output at 6:00 to 8:00 on morning and between 5:00 and 7:00 on afternoon for TDOX. Also, COX could be sampled at 6:00 to 8:00 on morning and between 5:00 and 7:00 on afternoon. External markers could be evaluated from 3-day fecal spot collection. Fecal collections could be made before the morning feeding, and around 6 p.m. for both markers.


Asunto(s)
Heces , Animales , Biomarcadores , Ovinos
3.
Trop Anim Health Prod ; 53(5): 454, 2021 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-34536113

RESUMEN

This study was conducted to evaluate the effects of including palm kernel cake (PKC) in high-concentrate diets for feedlot goat kids on nutrient intake, digestibility, feeding behavior, nitrogen balance, blood metabolites, and performance. Thirty-two castrated crossbred Boer × mixed breed goat kids with an average age of 4 months and an initial body weight of 19.65 ± 3.00 kg were distributed in a completely randomized design. The diets included one of four levels (0, 12, 24, and 36%) of PKC on a total dry matter basis. The PKC inclusion in the diets promoted quadratic effects in the nutrient intakes (P ≤ 0.05). The digestibility of ether extract increased (P = 0.010), whereas the digestibility of non-fibrous carbohydrates decreased (P = 0.017) with the inclusion of PKC. Palm kernel cake inclusion promoted a quadratic effect on the time spent per episode feeding and decreased the times spent idling and ruminated bolus per day (P ≤ 0.05). The ingested and retained nitrogen decreased with the inclusion of PKC (P ≤ 0.05). The inclusion of PKC in the diets had quadratic effects in the cholesterol concentrations, albumin (A), globulin (G), A:G ratio, and gamma-glutamyltransferase enzyme activity (P ≤ 0.05). The PKC inclusion promoted a quadratic increase in total weight gain (P = 0.026), with the highest value achieved at the inclusion level of 11.68%. The inclusion of up to 12% PKC in high-concentrate diets increases the intake and growth performance without compromising the digestibility of nutrients and feed efficiency.


Asunto(s)
Digestión , Cabras , Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Dieta/veterinaria , Ingestión de Alimentos , Conducta Alimentaria , Nitrógeno
4.
Trop Anim Health Prod ; 54(1): 17, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34910258

RESUMEN

This study aimed to evaluate the intake, digestibility, feeding behavior, performance, carcass traits, and meat quality of feedlot Santa Inês (locally adapted breed) and Dorper (transboundary breed) lambs. Twenty non-castrated lambs were used (10 from the Santa Inês genetic group and 10 Dorper), with approximately 3 months of age and an initial body weight of 22.95 ± 2.1 kg (mean ± standard deviation), distributed in a completely randomized design. Nutrient intake and digestibility, feeding behavior, and liver metabolism enzymes were similar (P > 0.05) between genetic groups. Dry matter (DM) feeding and ruminating efficiency were higher (P < 0.05) in the Santa Inês genetic group. There was also no difference (P > 0.05) in the subjective evaluation and morphometric measurements. Genetic groups showed differences and trend to differences (P < 0.05) in performance and commercial cuts. The physicochemical characteristics, centesimal composition, and sensory attributes of the Longissimus lumborum muscle did not differ between the genetic groups (P > 0.05). The Santa Inês genetic group showed higher feeding efficiency and productive parameters when compared to Dorper lambs. Therefore, Santa Inês lambs have greater potential for meat production than Dorper lambs, when kept in the same breeding system as the feedlot.


Asunto(s)
Carne , Ovinos , Animales , Peso Corporal , Dieta , Ingestión de Energía , Conducta Alimentaria , Ovinos/genética
5.
Trop Anim Health Prod ; 53(2): 201, 2021 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-33687567

RESUMEN

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.


Asunto(s)
Fenómenos Fisiológicos Nutricionales de los Animales , Búfalos/metabolismo , Dieta/veterinaria , Proteínas en la Dieta/administración & dosificación , Omaso/química , Rumen/metabolismo , Fenómenos Fisiológicos Nutricionales de los Animales/efectos de los fármacos , Animales , Fibras de la Dieta/metabolismo , Proteínas en la Dieta/farmacología , Digestión , Glicerol , Gossypium , Masculino , Omaso/efectos de los fármacos , Omaso/metabolismo , Rumen/química , Rumen/efectos de los fármacos , Proteínas de Soja , Zea mays
6.
Mol Biol Rep ; 46(1): 451-460, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30443821

RESUMEN

This study was conducted to evaluate the fermentative profile and microbial populations of wilted and non-wilted alfalfa silages ensiled with or without inoculant and the population dynamics of lactic acid bacteria (LAB) of wilted alfalfa plant and theirs silage. A 2 × 2 × 6 factorial arrangement was used, with the absence or presence of wilting (W), with and without bacterial inoculant (I) and six fermentation periods (P) (1, 3, 7, 14, 28 and 56 days), in a completely randomized design, with three replicates. The alfalfa was slightly wilted for 6 h and increased the dry matter content from 133.9 to 233.4 g/kg. It was performed the cultivation, followed by the isolation of LAB from samples of alfalfa forage before ensiling and its silage only in non-inoculated silages, after different fermentation periods. DNA was extracted from the isolated strains of LAB; the 16S rRNA gene sequences were amplified by PCR and the sequences were compared to those available from the GenBank database. Wilting provided silages with lower pH, ammonia nitrogen and acetic acid concentrations. The wilting process did not alter the amount of LAB; however, it affected the LAB diversity of the silages. The Lactobacillus plantarum was the predominant species in non-wilted and wilted silages.


Asunto(s)
Lactobacillales/genética , Medicago sativa/genética , Medicago sativa/microbiología , Ácido Acético , Amoníaco , Fermentación , Genética de Población/métodos , Concentración de Iones de Hidrógeno , Ácido Láctico , Lactobacillus/genética , Lactobacillus plantarum/genética , Nitrógeno , Ensilaje/microbiología , Clima Tropical
7.
BMC Vet Res ; 15(1): 401, 2019 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-31703601

RESUMEN

BACKGROUND: Dyslipidemias induce angiogenesis and accelerate the development and in vitro growth of breast tumors. The aim of this study was to assess the lipid and metabolic profile of female dogs with mammary carcinomas and their correlations with body condition score and degree of tumor malignancy, as well as to study the effect of dietary fish oil supplementation on these animals. RESULTS: Overweight or obese dogs had more aggressive carcinomas and higher triglyceride (p = 0.0363), VLDL (p = 0.0181), albumin (p = 0.0188), globulin (p = 0.0145) and lactate (p = 0.0255) concentrations. There was no change in the lipid profile after supplementation with fish oil at any concentration. However, in relation to the metabolic profile, glucose (p = 0.0067), total protein (p = 0.0002) and globulin (p = 0.0002) concentrations were increased when 90% omega-3 fish oil was used as a dietary supplement. CONCLUSION: Obese dogs showed altered lipid and metabolic profiles and more aggressive tumors, suggesting an important relationship between dyslipidemia and tumor aggressiveness. Supplementation with fish oil, rich in omega-3 fatty acids, may alter metabolic parameters in cancer patients.


Asunto(s)
Carcinoma/veterinaria , Aceites de Pescado/farmacología , Lípidos/sangre , Neoplasias Mamarias Animales/metabolismo , Metaboloma , Animales , Carcinoma/metabolismo , Suplementos Dietéticos , Perros , Femenino , Aceites de Pescado/administración & dosificación , Neoplasias Mamarias Animales/cirugía , Mastectomía/veterinaria , Obesidad , Ovariectomía/veterinaria
8.
Trop Anim Health Prod ; 50(4): 721-726, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29260488

RESUMEN

In this study, we evaluated the effects of including cassava wastewater in the diet on the feeding behavior of feedlot lambs in 35 male uncastrated Santa Inês × Dorper crossbred lambs at an approximate age of 3 months, with an average live weight of 20.0 ± 3.4 kg. Diets were formulated with hay of cassava shoots (roughage) and a concentrate based on corn and soybean, with a roughage:concentrate ratio of 50:50, plus inclusion of cassava wastewater at the levels of 0, 12, 24, 36, or 48 g/kg of the total diet. Feeding behavior was evaluated between the 46th and 52nd days of the experiment. Increasing cassava wastewater levels in the diet reduced (P < 0.05) the intakes (kg/day) of dry matter and neutral detergent fiber as well as the efficiency of rumination (g/cud and g/h) of dry matter and neutral detergent fiber. The other behavioral parameters were not affected by wastewater inclusion in the diet. Therefore, the inclusion of up to 48 g/kg of cassava wastewater on fresh matter of diets is not recommended for feedlot lambs.


Asunto(s)
Alimentación Animal/efectos adversos , Conducta Alimentaria/efectos de los fármacos , Manihot , Ovinos , Aguas Residuales/toxicidad , Animales , Dieta/veterinaria , Fibras de la Dieta , Masculino , Oveja Doméstica , Glycine max , Verduras , Zea mays
9.
Trop Anim Health Prod ; 49(2): 389-395, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27981417

RESUMEN

An investigation was made into the feeding behavior of goats to evaluate the effects of a detoxified castor bean meal in the diet of goats. Thirty-six ½ crossbred Boer goats were used, with an average weight of 20 ± 3.2 kg. A completely randomized design was used with four treatments (diets with of 0, 100, 200, and 300 g detoxified castor bean meals/kg dry matter) and nine replicates. Castor bean meal was detoxified using calcium oxide. Diets were formulated to be isonitrogenous, and the forage:concentrate ratio was 50:50. The feeding behavior was observed on the 17th, 45th, and 70th days of the experiment. For the evaluation of feeding behavior (feeding, idle, and rumination times), the animals were observed in 5-min intervals for 24 h. The addition of detoxified castor bean meal did not change (P > 0.05) the evaluated behavioral variables. Linear reduction was observed (P < 0.05) in the efficiencies of feeding and rumination, expressed in g dry matter/h. The variables related to the time series discretization of the feeding behavior of goats did not change (P > 0.05) with the inclusion of detoxified castor bean meal. The inclusion of detoxified castor bean meal in growing goats' diets does not change the feeding, rumination, and idle times, however, decreases intake, feeding, and rumination efficiencies of dry matter.


Asunto(s)
Alimentación Animal/análisis , Dieta/veterinaria , Conducta Alimentaria , Cabras , Animales , Biocombustibles , Peso Corporal , Ricinus communis , Femenino , Semillas
10.
Trop Anim Health Prod ; 46(2): 419-26, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24233571

RESUMEN

Beef cattle (24) with an average initial body weight of 417 ± 54 kg were assigned in a 2 × 2 factorial design with six repetitions. The factors studied were two levels of CP: 11 (low CP) or 13 % (high CP) in the initial feedlot phase (days 1 - 36) and in the final phase (days 37 - 72). After 36 days, half of the bulls fed with each level of CP were selected to reverse the CP level. No interaction was observed (P > 0.05) between the level of protein in the initial and final phases on the intake of the nutrients evaluated. There was no effect (P > 0.05) of the protein levels in the initial and final phases on intake of dry matter, organic matter, CP, non-fiber carbohydrates, and total digestible nutrients. No differences were observed among treatments (P > 0.05) for average daily gain (X = 1.99 kg/day) and carcass traits. We conclude that it is possible to feed Holstein-Zebu crossed bulls with an average daily gain of approximately 2 kg using a fixed level of 11 % CP during the entire feedlot period, and this diet is economically viable and environmentally sound.


Asunto(s)
Alimentación Animal/análisis , Composición Corporal/efectos de los fármacos , Bovinos/fisiología , Proteínas en la Dieta/farmacología , Compuestos de Nitrógeno/química , Animales , Peso Corporal , Dieta/veterinaria , Masculino
11.
Trop Anim Health Prod ; 44(6): 1303-10, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22246541

RESUMEN

The objective of this study was to evaluate the nutrient intake and milk production in Holstein × zebu (F1) cows in feedlot. Eighteen F1 cows were used, divided into three treatments; six were Holstein × Gir (HGI), six were Holstein × Guzerat (HGU), and another six were Holstein × Nelore (HNE), which had recently calved, distributed into simple, random samples, under the same feeding conditions of corn silage and concentrate with 20% crude protein. The three-marker method was used (LIPE, titanium dioxide, and iADF) to estimate the individual intake and digestibility of the nutrients for the cows in group. The mathematical model used to establish the lactation curves was: Y = at(b)e(-ct) by Wood (Nature 216:164-165, 1967). The statistical analyses for the nutrient intake and digestibility, as well as parameters of metabolic efficiency, were performed using multiple linear regression (α = 5%). No effect (P > 0.05) of genetic group was observed for any of the variables studied. The intake and digestibility of the nutrients and the microbial nitrogen presented quadratic curves as a function of the lactation period (P < 0.05). The HGU cows exhibited an accumulated milk production of 4,946.81 kg at 305 days, whereas the HGI cows produced 4,821.78 kg. The HNE cows displayed inferior performance, with a production of 3,674.98 kg. It was concluded that, in confinement, F1 cows from different genetic groups do not exhibit different intake, digestibility, or metabolic efficiency. The HGU and HGI cows have greater cumulative production at 305 days.


Asunto(s)
Bovinos/fisiología , Cruzamientos Genéticos , Industria Lechera/estadística & datos numéricos , Ingestión de Alimentos/fisiología , Leche/fisiología , Animales , Ingestión de Alimentos/genética , Femenino , Lactancia/genética , Lactancia/fisiología , Modelos Lineales , Leche/estadística & datos numéricos , Modelos Biológicos , Titanio
12.
Sci Rep ; 12(1): 18154, 2022 10 28.
Artículo en Inglés | MEDLINE | ID: mdl-36307521

RESUMEN

The protein requirements of hair sheep are a key factor in increasing profitability and decreasing the environmental impacts of nitrogen excretion. The objective of this study was to evaluate the protein requirements of hair sheep. A database with 382 individual records (269 intact and 113 castrated males) comprising information from 11 studies was used. The studies provided different levels of metabolisable protein intake (MPI) and of N retention, allowing the development of equations to predict the net protein (NP) and the metabolisable protein (MP) requirements. The efficiency of MP use for gain (kpg) was calculated using the equation of daily protein retained against daily MPI above maintenance. The efficiency of MP use for maintenance (kpm) was computed as the ratio between the NP for maintenance (NPm) and the MP for maintenance (MPm). The NPm (1.32 g/kg0.75 EBW) did not differ between sex. The kpm was 0.34, and the kpg was 0.25. The MPm estimated was 3.21 g/kg0.75 BW. Sex affects the protein requirements for gain (NPg). The protein requirements of hair sheep differ from those recommended by feeding systems for sheep. The equations provided herein may improve the optimisation of protein nutrition of sheep, thereby minimising the environmental impacts of sheep production.


Asunto(s)
Fenómenos Fisiológicos Nutricionales de los Animales , Proteínas en la Dieta , Masculino , Ovinos , Animales , Necesidades Nutricionales , Proteínas en la Dieta/metabolismo , Alimentación Animal/análisis , Dieta/veterinaria , Composición Corporal , Metabolismo Energético , Peso Corporal
13.
Vet Anim Sci ; 11: 100168, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33598586

RESUMEN

This Research aimed to evaluate the metabolic status and behavior changes during the transition period in dairy goats from three breeds, under tropical conditions. Thirty multiparous female goats were kept in pens, distributed randomly by breeds. Infrared cameras were fitted in the pens to monitor the animals, and its activities were recorded. Goats displayed varied idle, standing, walking, and feeding behaviors at kidding day (P < 0.10) when compared with the days after and before. Agnostic interactions prevailed between 3.33 and 7.98% of the time on the day of kidding. There was a day effect for the exploratory activities (P < 0.10), where the most exploratory activities were observed on the day of kidding. The milk production and fat content differed according to breed and lactation week. Collective pens for lactating goats, kept in a tropical environment, do not compromise the social behavior and welfare.

14.
Front Vet Sci ; 8: 650248, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34179156

RESUMEN

Microbial crude protein (MCP) produced in rumen could be estimated by a variety of protocols of experimental sampling and analysis. However, a model to estimate this value is necessary when protein requirements are calculated for small ruminants. This model could be useful to calculate rumen degradable protein (RDP) requirements from metabolizable protein (MP). Then, our objective was to investigate if there is a difference in MCP efficiency between sheep and goats, and to fit equations to predict ruminal MCP production from dietary energy intake. The database consisted of 19 studies with goats (n = 176) and sheep (n = 316), and the variables MCP synthesis (g/day), total digestible nutrients (TDN), and organic matter (OM) intakes (g/day), and OM digestibility (g/kg DM) were registered for both species. The database was used for two different purposes, where 70% of the values were sorted to fit equations, and 30% for validation. A meta-analytical procedure was carried out using the MIXED procedure of SAS, specie was considered as the fixed dummy effect, and the intercept and slope nested in the study were considered random effects. No effect of specie was observed for the estimation of MCP from TDN, digestible Organic Matter (dOM), or metabolizable energy (ME) intakes (P > 0.05), considering an equation with or without an intercept. Therefore, single models including both species at the same fitting were validated. The following equations MCP (g/day) = 12.7311 + 59.2956 × TDN intake (AIC = 3,004.6); MCP (g/day) = 15.7764 + 62.2612 × dOM intake (AIC = 2,755.1); and MCP (g/day) = 12.7311 + 15.3000 × ME intake (AIC = 3,007.3) presented lower values for the mean square error of prediction (MSEP) and its decomposition, and similar values for the concordance correlation coefficient (CCC) and for the residual mean square error (RMSE) when compared with equations fitted without an intercept. The intercept and slope pooled test was significant for equations without an intercept (P < 0.05), indicating that observed and predicted data differed. In contrast, predicted and observed data for complete equations were similar (P > 0.05).

15.
PLoS One ; 15(11): e0242822, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33227032

RESUMEN

The objective of this study was to evaluate the effects of the association of cottonseed processing method with chitosan on carcass traits and meat quality of lambs finished in feedlot. Eighty lambs with an average body weight of 20.6 kg, with 04 months of age, were distributed in a completely randomized design, in a 2 x 2 factorial arrangement. The factors were represented by two cottonseed processing method (whole or ground) and two levels of chitosan (0 and 136 mg/kg BW). The association of cottonseed processing method with chitosan in the lamb diet did not affect (P>0.05) carcasses traits. The pH, color, cooking losses, shear force, and proximate composition of meat were also not affected (P>0.05) by the processing method of cottonseed or its association with chitosan in the lamb diets. There was an increase in palmitoleic (c9-C16:1; P = 0.01) and conjugated linoleic (P = 0.02) fatty acids when ground cottonseed was associated with chitosan. Ground cottonseed associated with chitosan increases the concentration of unsaturated fatty acids in the meat of feedlot lambs.


Asunto(s)
Alimentación Animal , Quitosano/química , Aceite de Semillas de Algodón/química , Manipulación de Alimentos , Animales , Composición Corporal/efectos de los fármacos , Peso Corporal , Ácidos Grasos Insaturados/química , Humanos , Carne/normas , Carne Roja , Ovinos/crecimiento & desarrollo , Oveja Doméstica
16.
J Anim Sci ; 96(6): 2453-2467, 2018 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-29668924

RESUMEN

The objectives of this study were to evaluate the effect of reducing dietary CP contents on 1) total and partial nutrient digestion and nitrogen balance and 2) on microbial crude protein (MCP) synthesis and true MCP digestibility in the small intestine obtained with 15N and purine bases (PB) in beef cattle. Eight bulls (4 Nellore and 4 Crossbred Angus × Nellore) cannulated in the rumen and ileum were distributed in duplicated 4 × 4 Latin squares. The diets consisted of increasing CP contents: 100, 120, or 140 g CP/kg DM offered ad libitum, and restricted intake (RI) diet with 120 g CP/kg DM. The experiment lasted four 17-d periods, with 10 d for adaptation to diets and another 7 for data collection. Omasal digesta flow was obtained using Co-EDTA and indigestible NDF (iNDF) as markers, and to estimate ileal digesta flow only iNDF was used. From days 11 to 17 of each experimental period, ruminal infusions of Co-EDTA (5.0 g/d) and 15N (7.03 g of ammonium sulfate enriched with 10% of 15N atoms) were performed. There was no effect of CP contents (linear effect, P = 0.55 and quadratic effect, P = 0.11) on ruminal OM digestibility. Intake of CP linearly increased (P < 0.01) with greater dietary CP. The NH3-N (P < 0.01) and urinary N excretion (P < 0.01) increased in response to dietary CP, whereas retained N increased linearly (P = 0.03). Liquid-associated bacteria (LAB) in the omasum had greater N content (P < 0.05) in relation to the particle-associated bacteria (PAB). There was no difference between LAB and PAB (P = 0.12) for 15N:14N ratio. The 15N:14N ratio was greater (P < 0.01) in RI animals in relation to those fed at voluntary intake. Microbial CP had a quadratic tendency (P = 0.09) in response to CP increase. Microbial efficiency (expressed in relation to apparent ruminally degradable OM and true ruminally degradable OM) had a quadratic tendency (P = 0.07 and P = 0.08, respectively) to CP increasing and was numerically greatest at 120 g CP/kg DM. The adjusted equations for estimating true intestinal digestibility of MCP (Y1) and total CP (Y2) were, respectively, as follows: Y1 =--16.724(SEM = 40.06) + 0.86X(SEM = 0.05) and Y2 = -43.81(SEM = 49.19) + 0.75X(SEM = 0.05). It was concluded that diets with 120 g/kg of CP optimize the microbial synthesis and efficiency and ruminal ash and protein NDF digestibility, resulting in a better use of N compounds in the rumen. The PB technique can be used as an alternative to the 15N to estimate microbial synthesis.


Asunto(s)
Aminoácidos/metabolismo , Alimentación Animal/análisis , Bovinos/fisiología , Proteínas en la Dieta/metabolismo , Nitrógeno/metabolismo , Animales , Bacterias/metabolismo , Dieta/veterinaria , Digestión , Íleon/metabolismo , Masculino , Purinas/metabolismo , Rumen/metabolismo
17.
PLoS One ; 11(12): e0169170, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-28036405

RESUMEN

The objective of this study was to evaluate the effects of increasing dietary crude protein (CP) levels and also comparing the effects of static versus oscillating dietary CP on ruminal nutrient digestibility, ruminal fermentation, nitrogen (N) metabolism, and microbial efficiency in beef cattle diets using a dual-flow continuous culture system. Eight fermenters (1,223 ± 21 mL) were used in a replicated 4 x 4 Latin square design with periods lasting 12 d each (8 d for adaptation and 4 d for sampling). Dietary treatments were: 1) 10% CP, 2) 12% CP, 3) 14% CP, and 4) 10 and 14% CP diets oscillating at 48-h intervals. Experimental diets consisted of 50% orchard hay and 50% concentrate. Fermenters were fed 72 g/d and solid and liquid dilution rates were adjusted to 5.5 and 11%/h, respectively. Data were analyzed using the MIXED procedure in SAS with α = 0.05. Apparent and true ruminal digestibilities of dry matter and organic matter were not affected (P > 0.05) by increasing dietary CP, nor by oscillating dietary CP. Total volatile fatty acids concentration and molar proportions of acetate, propionate, butyrate, valerate, iso-butyrate and iso-valerate were not affected (P > 0.05) by increasing or oscillating dietary CP. Ruminal NH3-N concentration increased linearly (P < 0.01) in response to increasing dietary CP. Total N, non-ammonia N, and rumen undegraded protein flows did not differ among treatments or between oscillating dietary CP and static 12% CP. Microbial N and NH3-N flows and microbial efficiency did not differ when comparing oscillating versus static CP (P > 0.05). However, there was a quadratic effect (P < 0.05) for these variables when dietary CP was increased. These results indicate that either ruminal microorganisms do not respond to oscillating CP levels or are capable of coping with 48-h periods of undernourishment.


Asunto(s)
Alimentación Animal/análisis , Reactores Biológicos , Dieta/veterinaria , Proteínas en la Dieta/análisis , Digestión/fisiología , Fermentación , Rumen/metabolismo , Amoníaco/metabolismo , Fenómenos Fisiológicos Nutricionales de los Animales/fisiología , Animales , Bovinos , Proteínas en la Dieta/administración & dosificación , Proteínas en la Dieta/química , Suplementos Dietéticos , Ácidos Grasos/metabolismo , Nitrógeno/metabolismo
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