RESUMO
Following a comparison of nutrient total-tract digestibility estimates in lactating buffaloes using single-point undigestible NDF (uNDF) or acid-insoluble ash (AIA) as internal markers, the potential of fecal near-infrared spectroscopy (NIRS) to provide calibration equations for the assessment of the chemical composition of feces and nutrient total-tract digestibility estimated with internal markers was explored. Chemical analyses were performed on 147 fecal samples from lactating buffaloes reared on 5 farms in central Italy (Naples). Each farm fed a silage-based TMR to the buffaloes, and the TMR was sampled in the 2 d before the fecal collection. The TMR and individual fecal samples were collected and analyzed for DM, OM, ash, AIA, ether extract (EE), starch, fiber fractions (amylase-treated NDF without residual ash [aNDFom], amylase-treated NDF inclusive of residual ash [aNDF], ADF without residual ash [ADFom], ADF, hemicellulose, cellulose, ADL, uNDF), N, CP and CP bound to aNDF (NDICP) and to ADF (ADICP). The uNDF content was determined through a 240-h in vitro fermentation and employed, together with AIA as markers, to estimate the total-tract apparent digestibility and total-tract digestibility of DM, OM, ash, N, CP, EE, aNDFom, aNDF, NDIP, ADFom, and ADF, ADIN, ADL, hemicellulose, cellulose, starch, NFC, and the B3 fraction of N (NB3). No correlation was found between DM and OM digestibility estimated with AIA and uNDF as internal markers. Weak correlations were detected for all the other nutients digestibilities, and strong correlations were observed for EE, ADFom, hemicellulose, NDIN, ADIN, NB3, NFC, and starch. The sample set (n = 147) was divided in a calibration set (n = 111) and a validation set (n = 36) to "train" and "validate" the fecal NIRS curve through an external validation process. An estimation usable for preliminary or initial evaluation was obtained for N, CP, and aNDF fecal content. An excellent prediction was obtained for total tract digestibility of ADIN (R2 = 0.90) when estimated with uNDF as the internal marker. The NIRS technology was not able to accurately predict all the other traits and the estimated nutrient digestibility of lactating buffalo diets from fecal spectra.
Assuntos
Búfalos , Fibras na Dieta , Digestão , Fezes , Lactação , Espectroscopia de Luz Próxima ao Infravermelho , Animais , Fezes/química , Feminino , Espectroscopia de Luz Próxima ao Infravermelho/veterinária , Dieta/veterinária , Ração Animal/análise , Nutrientes/análise , SilagemRESUMO
A network meta-analysis was conducted to determine the effects of feeding feed-grade urea (FGU) or slow-release urea (SRU) as a replacement for true protein supplements (control; CTR) in high-producing dairy cattle diets. Research papers were selected (n = 44) from experiments published between 1971 and 2021 based on the following criteria: dairy breed, detailed description of the isonitrogenous diets fed, provision of FGU or SRU (or both), high-yielding cows (>25 kg/cow per day), and results that included at least milk yield and composition, but data on nutrient intake, digestibility, ruminal fermentation profile, and N utilization were also considered. Most studies compared only 2 treatments, and a network meta-analysis approach was adopted to compare the effects among CTR, FGU, and SRU. Data were analyzed using a generalized linear mixed model network meta-analysis. Forest plots of milk yield were used to visualize the estimated effect size of treatments. Cows included in the study produced 32.9 ± 5.7 L/d of milk, 3.46 ± 5.0% of fat, and 3.11 ± 0.2% of protein with an intake of 22.1 ± 3.45 kg of dry matter. Average diet composition was 1.65 ± 0.07 Mcal of net energy for lactation, 16.4 ± 1.45% CP, 30.8 ± 5.91% neutral detergent fiber, and 23.0 ± 4.62% starch. Average supply of FGU was 209 g/cow per day, whereas the average supply of SRU was 204 g/cow per day. With some exceptions, feeding FGU and SRU did not affect nutrient intake and digestibility, N utilization, and milk yield and composition. However, the FGU reduced the acetate proportion (61.6 vs. 59.7 mol/100 mol) and the SRU reduced the butyrate proportion (12.4 vs. 11.9 mol/100 mol) compared with CTR. Ruminal ammonia-N concentration increased from 8.47 to 11.5 and 9.3 mg/dL in CTR, FGU, and SRU, respectively. Urinary nitrogen excretion increased from 171 to 198 g/d in CTR versus the 2 urea treatments, respectively. The use of moderate doses of FGU in high-producing dairy cows may be justified based on its lower cost.
Assuntos
Lactação , Ureia , Feminino , Bovinos , Animais , Ureia/metabolismo , Ração Animal/análise , Metanálise em Rede , Digestão , Melhoramento Vegetal , Leite/química , Dieta/veterinária , Rúmen/metabolismo , FermentaçãoRESUMO
Although there are several studies comparing organic and conventional milk characteristics, very few focused on dairy processed products such as cheese. Thus, this study aimed for a detailed controlled examination of gross composition, minerals, and the fatty acid profile of organic (ORG) and conventional (CON) Italian cheeses from parallel production. Four Italian cheese types were analyzed: Latteria (ORG, n = 9; CON, n = 10); Asiago Protected Designation of Origin (PDO) fresco (ORG, n = 9; CON, n = 9); Caciotta (ORG, n = 8; CON, n = 8); and Mozzarella Traditional Specialty Guaranteed (TSG; ORG, n = 14; CON, n = 14). Cheese samples were collected from September 2020 to August 2021. Gross composition, minerals, and fatty acids were determined using infrared spectroscopy. Within each cheese type, paired ORG and CON samples were compared using a nonparametric Wilcoxon signed-rank test. Latteria showed lower PUFA, n-3, and n-6 content, and greater Fe, K, C10:0, C12:0, and C16:0 content in ORG than in CON. Asiago PDO fresco showed lower protein and Zn content and greater salt, ash, and Na content in ORG than in CON. Caciotta showed lower ash, n-3, and n-6 content and greater K, C4:0, C8:0, C10:0, C14:0, and C16:0 content in ORG than in CON. Mozzarella TSG showed lower fat and, therefore, fatty acid content, and greater moisture, ash, and Mg content in ORG than in CON. In conclusion, few significant differences in chemical composition were observed between ORG and CON cheeses, regardless of the type considered. Moreover, Asiago PDO fresco showed fewer significant differences between ORG and CON compared with Latteria, Caciotta, and Mozzarella TSG.
Assuntos
Queijo , Animais , Leite/química , Ácidos Graxos/análise , Minerais/análise , ItáliaRESUMO
A short-term study was conducted to compare the effect of using poplar wood chips (PWC) instead of wheat straw (WS) litter in dairy cows. A total of 38 lactating Holstein cows (204 ± 119 days in milk, 26.9 ± 6.5 kg of milk yield [MY]) were housed in a tiestall farm for a 10-d trial including 5 d of adaptation followed by 5 sampling days (from d 5 to 10). Cows were divided into 2 homogeneous groups: one group was bedded with WS, and the second with PWC. Both litter materials were provided in the amount of 7 kg/stall per d. Each group was composed of 3 subgroups of 6 or 7 cows; the subgroups were physically separated along the feeding line by wooden boards. During the sampling days, fecal composition, used litter composition, and bacterial count (Clostridium spp., Salmonella spp., Escherichia coli, Lactobacillus, and total bacterial count) were analyzed by subgroup twice a day. On d 1 and from d 5 to 10, udder hygiene score and cow cleanliness score were also evaluated individually twice a day. Meanwhile MY, milk hygiene (total bacterial count [TBC], coliform bacterial count [CBC], and spore-forming units [SFU]) and quality were measured and analyzed from 9 animals per group. Moreover, individual animal behavior (body position and behavioral traits) and subgroup dry matter intake were measured on d 9 and 10. Fecal dry matter did not differ between groups, PWC had the lowest used litter moisture and N content favoring the highest clean cow frequency, but also gave rise to the greatest used litter microbial contamination. The MY, milk quality, TBC, SFU, and CBC were similar. The lying behavior frequency was similar between groups. However, the PWC group showed the lowest sleeping frequency, the highest frequency of other behaviors (including discomfort signs), and the lowest dry matter intake. However, despite this apparent reduction in cow comfort, no biologically important differences were observed in this short-term study between cows on PWC and WS in milk production or hygiene.
Assuntos
Lactação , Leite , Feminino , Bovinos , Animais , Triticum , Madeira , Comportamento Animal , Higiene , Dieta/veterináriaRESUMO
The theme of iodine in the dairy sector is of particular interest due to the involvement and the interconnection of several stakeholders along the dairy food chain. Iodine plays a fundamental role in animal nutrition and physiology, and in cattle it is an essential micronutrient during lactation and for fetal development and the calf's growth. Its correct use in food supplementation is crucial to guarantee the animal's recommended daily requirement to avoid excess intake and long-term toxicity. Milk iodine is fundamental for public health, being one of the major sources of iodine in Mediterranean and Western diets. Public authorities and the scientific community have made great efforts to address how and to what extent different drivers may affect milk iodine concentration. The scientific literature concurs that the amount of iodine administered through animal feed and mineral supplements is the most important factor affecting its concentration in milk of most common dairy species. Additionally, farming practices related to milking (e.g., use of iodized teat sanitizers), herd management (e.g., pasture vs. confinement), and other environmental factors (e.g., seasonality) have been identified as sources of variation of milk iodine concentration. Overall, the aim of this review is to provide a multilevel overview on the mechanisms that contribute to the iodine concentration of milk and dairy products.
Assuntos
Iodo , Oligoelementos , Feminino , Bovinos , Animais , Iodo/análise , Leite/química , Lactação/fisiologia , Ração Animal/análise , Dieta/veterináriaRESUMO
Several studies have reported gross composition differences between organic and conventional milk; however, most studies have not considered other factors such as breed and diet ingredients, which are known to influence milk composition. Thus, this study aimed to provide a detailed characterization of Holstein-Friesian cow milk from organic (ORG) and conventional (CONV) herds with similar diet ingredients and in the same geographic area. Bulk milk samples (n = 225) of 12 ORG and 12 CONV farms were collected from September 2019 to August 2020. Farms were located in Northern Italy, included corn (meal, silage, or both) in the lactating diets, and had similar management conditions, but ORG herds spent a period on pasture. Factors affecting milk composition were tested using a linear mixed model, which included calendar month, farming system (ORG and CONV), and their interactions as fixed effects, and farm nested within farming system as random effect. Results showed that total fat, lactose, vitamin E, and AA did not significantly differ between farming systems. Total protein and casein contents were significantly lower in ORG than CONV herds, and somatic cell score (SCS) was greater in ORG than CONV. Among minerals, differences were observed for Fe, K, Mg, and S in some months, being lower in ORG than CONV for K, Mg, and S and greater or lower for Fe depending on the month. Among fatty acid (FA) groups, index, and ratios, only polyunsaturated FA and n-3 FA tended to be greater in ORG than CONV, and cis-FA were greater in ORG than CONV during October. Among the most abundant individual FA, only C16:1n-9 differed, being lower in ORG than CONV. The calendar month (and hence seasonal feed ration) was significant for milk gross composition, SCS, vitamin E, mineral profile (except for Mo, Sr, and Zn), AA profile, FA groups (except for medium-chain FA), FA index and ratios, and individual FA (except C16:0). We conclude that the overall milk composition was quite similar between the 2 farming systems. This could be related to the similarity of the selected farms, the Holstein-Friesian breed, and generally high level of intensity in both farming systems.
Assuntos
Lactação , Leite , Animais , Bovinos , Dieta/veterinária , Ácidos Graxos/metabolismo , Feminino , Leite/metabolismo , Melhoramento Vegetal , Silagem , Vitamina E/metabolismoRESUMO
The aim of the present study was to investigate sources of variation of milk composition and technological characteristics routinely collected in field conditions in the Italian dairy industry. A total of 40,896 bulk milk records from 620 herds and 10 regions across Italy were analyzed. Composition traits were fat, protein, and casein percentages, urea content, and somatic cell score; and technological characteristics were rennet coagulation time, curd firming time, curd firmness 30 min after rennet addition to milk, and titratable acidity. Data of herd bulk milks were analyzed using a model that included fixed effects of region, herd nested within region, and season of milk analysis. An average good milk quality was reported in the dairy industry (especially concerning fat, protein, and casein percentages), and moderate to high correlations between composition and technological traits were observed. All factors included in the statistical model were significant in explaining the variation of the studied traits except for region effect in the analysis of casein and somatic cell score. Northeast and central-southern Italian regions showed the best performance for composition and technological features, respectively. Traits varied greatly across regions, which could reflect differences in herd management and strategies. Overall, less suitable milk for dairy processing was observed in summer. Results of the present study suggested that a constant monitoring of technological traits in the dairy industry is necessary to improve production quality at herd level and it may be a way to segregate milk according to its processing characteristics.
Assuntos
Indústria de Laticínios/métodos , Leite/química , Animais , Bovinos , ItáliaRESUMO
The massive development of the pet food industry in recent years has lead to the formulation of hundreds of canine and feline complete extruded foods with the objective of meeting both the needs of the animals and numerous demands from pet owners. In the meantime, highly variable raw material compositions and the industry's new production techniques oblige manufacturers to monitor all phases of the extrusion process closely in order to ensure the targeted composition and quality of the products. This study aimed at evaluating the potential of infrared technology (visible and near-infrared spectrophotometer; 570-1842 nm) in predicting the chemical composition and peroxide value (PV) of unground commercial extruded dog foods. Six hundred and forty-nine commercial extruded dog foods were collected. For each product, an unground aliquot was analysed by infrared instrument while a second aliquot was sent to a laboratory for proximate analysis and PV quantification. The wide range of extruded dog food typologies included in the study was responsible for the wide variability observed within each nutritional trait, especially crude fibre and ash. The mean value of the 208 pet foods sampled for PV quantification was 17.49 mEq O2 /kg fat (min 2.2 and max 94.10 mEq O2 /kg fat). The coefficients of determination in cross-validation of NIRS prediction models were 0.77, 0.97, 0.83, 0.86, 0.78 and 0.94 for moisture, crude protein, crude fat, crude fibre, ash and nitrogen-free extract (NFE) respectively. PV prediction was less precise, as demonstrated by the coefficient of determination in cross-validation (0.66). The results demonstrated the potential of NIRS in predicting chemical composition in unground samples, with lower accuracy for moisture and ash, while PV prediction models suggest use for screening purposes only.
Assuntos
Ração Animal/análise , Manipulação de Alimentos/métodos , Peróxidos/química , Análise Espectral/métodos , Animais , Fibras na Dieta/análise , Proteínas Alimentares/análise , Valor NutritivoRESUMO
A combined experimental evaluation of methane production (obtained by anaerobic digestion) and detailed digestate characterization (with physical-chemical, thermo-gravimetric and mineralogical approaches) was conducted on two organic substrates, which are specific to Italy (at regional and national levels). One of the substrates was grape seeds, which have an agricultural origin, whereas the other substrate was vegetable-tanned leather dust, which has an industrial origin. Under the assumed experimental conditions of the performed lab-scale test series, the grape seed substrate exhibited a resulting net methane production of 175.0 NmL g volatile solids (VS)(-1); hence, it can be considered as a potential energy source via anaerobic digestion. Conversely, the net methane production obtained from the anaerobic digestion of the vegetable-tanned leather dust substrate was limited to 16.1 NmL gVS(-1). A detailed characterization of the obtained digestates showed that there were both nitrogen-containing compounds and complex organic compounds present in the digestate that was obtained from the mixture of leather dust and inoculum. As a general perspective of this experimental study, the application of diversified characterization analyzes could facilitate (1) a better understanding of the main properties of the obtained digestates to evaluate their potential valorization, and (2) a combination of the digestate characteristics with the corresponding methane productions to comprehensively evaluate the bioconversion process.
Assuntos
Reatores Biológicos , Resíduos Industriais , Metano/metabolismo , Eliminação de Resíduos/métodos , Curtume , Vitis , Anaerobiose , Biomassa , Cinética , Metano/análise , Sementes , EsgotosRESUMO
Nutrient synchronisation of protein and carbohydrates is a promising practice to improve ruminal nutrient utilisation. However, dietary sources supplying these nutrients can vary in ruminal nutrient availability due to differing degradation rates, therefore potentially affecting utilisation of nitrogen (N). The effects of the addition of non-fibre carbohydrates (NFCs) with different rumen degradation rates in high-forage diets on ruminal fermentation, efficiency and microbial flow were investigated in vitro using the Rumen Simulation Technique (RUSITEC). Four diets were tested: control with 100% ryegrass silage (GRS) and substitution of 20% on a DM basis of ryegrass silage with corn grain (CORN), processed corn (OZ) or sucrose (SUC). The four diets were assigned to 16 vessels in two sets of RUSITEC apparatuses in a randomised block design over a 17 d experimental trial; 10 d consisted of adaptation and 7 d for sample collection. Rumen fluid was collected from four rumen-cannulated dry Holstein-Friesian dairy cows and was treated without mixing. Then, rumen fluid from each cow was used to inoculate four vessels, and diet treatments were randomly allocated to each one. This was repeated for all cows resulting in 16 vessels. The inclusion of SUC in ryegrass silage diets improved DM and organic matter digestibility. The only diet to significantly lower ammonia-N concentration compared with GRS was SUC. The outflows of non-ammonia-N, microbial-N, and efficiency of microbial protein synthesis were not affected by diet type. However, the efficiency of nitrogen utilisation was improved by SUC compared with GRS. This indicates that the inclusion of an energy source with a high rumen degradation rate in high-forage diets improves rumen fermentation, digestibility, and N utilisation. Specifically, this effect was observed for the more readily available energy source, SUC, compared with the more slowly degradable NFC sources, CORN and OZ.
Assuntos
Lactação , Leite , Feminino , Bovinos , Animais , Leite/metabolismo , Rúmen/metabolismo , Dieta/veterinária , Silagem/análise , Zea mays/metabolismo , Carboidratos , Nitrogênio/metabolismo , Fermentação , DigestãoRESUMO
Camelina sativa is an alternative protein source (with a specific amino acid profile) rich also in bioactive compounds (such as polyunsaturated fatty acids and antioxidants), which have immunomodulatory properties. This study aimed to assess the impact of the dietary inclusion level of Camelina seeds, on the expression levels of key genes involved in ewes' innate immunity. Forty-eight dairy ewes were assigned into four homogenous groups of 12 animals that were fed individually with alfalfa hay, wheat straw, and concentrate. The concentrate of the control group (CON) had no Camelina seeds, while in the treated groups, Camelina seeds (CSs) were incorporated at 6 (CS6), 11 (CS11), and 16% (CS16) in the concentrates, respectively, as partial substitution of both soybean meal and maize grain. The relative transcript levels of the immune-related genes were determined using a real-time PCR platform. The relative transcript levels of toll-interleukin receptor-domain-containing adapter-inducing interferon-ß, tumour necrosis factor receptor-associated factor 3, Interferon regulatory factor 5, and Mitogen-activated protein kinase were upregulated in monocytes of the CS11-fed ewes. Furthermore, in the CS6-fed ewes, the relative transcript levels of Interleukin-1 beta (IL1B) were upregulated in monocytes compared to the CON, while those of IL1B, Interleukin-8, and Interleukin-10 were upregulated in neutrophils compared to the CON and the CS11-fed ewes. The highest inclusion level of CS (CS16) did not have a negative impact on ewes' innate immunity. The response of monocytes on dietary amino acid (mainly threonine, tyrosine, serine, and lysine) changes related to Camelina inclusion is different from that of neutrophils. The observed responses need to be further investigated.
Assuntos
Aminoácidos , Brassicaceae , Ração Animal/análise , Animais , Dieta/veterinária , Ácidos Graxos/análise , Ácidos Graxos Insaturados , Feminino , Imunidade Inata , Fatores Reguladores de Interferon , Interferon beta , Interleucina-10 , Interleucina-1beta , Interleucina-8 , Lisina , Proteínas Quinases Ativadas por Mitógeno , Sementes/química , Serina , Ovinos , Treonina , Peptídeos e Proteínas Associados a Receptores de Fatores de Necrose Tumoral , TirosinaRESUMO
The economic damage that results from aerobic deterioration of silage is a significant problem for farm profitability and feed quality. This paper quantifies the dry matter (DM) and nutritional losses that occur during the exposure of corn and sorghum silages to air over 14 d and assesses the possibility of enhancing the aerobic stability of silages through inoculation with lactic acid bacteria (LAB). The trial was carried out in Northern Italy on corn (50% milk line) and grain sorghum (early dough stage) silages. The crops were ensiled in 30-L jars, without a LAB inoculant (C), with a Lactobacillus plantarum inoculum (LP), and with a Lactobacillus buchneri inoculum (LB; theoretical rate of 1 × 10(6) cfu/g of fresh forage). The pre-ensiled material, the silage at silo opening, and the aerobically exposed silage were analyzed for DM content, fermentative profiles, yeast and mold count, starch, crude protein, ash, fiber components, 24-h and 48-h DM digestibility and neutral detergent fiber (NDF) degradability. The yield and nutrient analysis data of the corn and sorghum silages were used as input for Milk2006 to estimate the total digestible nutrients, net energy of lactation, and milk production per Mg of DM. The DM fermentation and respiration losses were also calculated. The inocula influenced the in vitro NDF digestibility at 24h, the net energy for lactation (NE(L)), and the predicted milk yield per megagram of DM, whereas the length of time of air exposure influenced DM digestibility at 24 and 48 h, the NE(L), and the predicted milk yield per megagram of DM in the corn silages. The inocula only influenced the milk yield per megagram of DM and the air exposure affected the DM digestibility at 24h, the NE(L), and the milk yield per megagram of DM in the sorghum silages. The milk yield, after 14 d of air exposure, decreased to 1,442, 1,418, and 1,277 kg/Mg of DM for C, LB, and LP corn silages, respectively, compared with an average value of 1,568 kg of silage at opening. In the sorghum silages, the milk yield, after 14 d of air exposure, decreased to 1,226, 1,278, and 1,250 kg/Mg of DM for C, LB, and LP, respectively. When the estimated milk yield per megagram of harvested DM of corn and sorghum silage were related to mold count, it was shown that the loss of potential milk production occurred when the mold count exceeded 4 log cfu/g of silage, and it was almost halved when the mold count reached values greater than 8 log cfu/g of silage. Inoculation with L. buchneri, at a rate of 1 × 10(6) cfu/g of fresh forage, enhanced the stability of the silage after exposure to air, and, consequently, contributed to maintaining the nutritional value of the harvested forage over time, for air exposure up to 7 d.
Assuntos
Lactobacillus/metabolismo , Silagem/microbiologia , Sorghum/microbiologia , Zea mays/microbiologia , Ar , Animais , Microbiologia de Alimentos , Valor Nutritivo , Fatores de TempoRESUMO
In the pig industry, labour efficiency and animal welfare have become two of the most important factors for achieving technical goals and farming competitiveness. Blood sampling is one of the most common sample-collecting techniques, but routine on-field blood collection can be very demanding for farm operators and the welfare of the animals, in particular for lactating sows. The aim of this study was to describe and investigate the mammary vein as a novel means of blood access in lactating sows that does not require coercive restraint. The study involved a total of 68 sows: 34 animals were sampled from the jugular vein (Group J) and the other 34 sows from the mammary vein (Group M). Labour time and indicators of the sow welfare (vocalizations during collection and serum cortisol concentration in the 30min after the procedure) were collected from the two groups. The total amount of labour required, calculated as the time employed to perform blood collection multiplied by the number of operators involved in performing the technique (one for Group M and two for Group J, one for restraint and one for sampling), was significantly lower in Group M than Group J (Group M, 39.83±29.45s; Group J, 82.73±55.34s; P<0.001). Mean blood volume collected at T0 was 4.81±2.00mL and 4.84±1.73mL in Group J and Group M, respectively (P>0.05). The percentage of sows that vocalized in Group M was less than in Group J (2.94% vs. 94.12%; P<0.001). Serum cortisol concentrations were not statistically different between the two groups (P>0.05). The present study suggests greater efficiency in terms of saving labour time and reducing sow vocalization during blood collection with the use of mammary vein access compared with jugular vein access.
Assuntos
Coleta de Amostras Sanguíneas/veterinária , Suínos/sangue , Bem-Estar do Animal , Animais , Coleta de Amostras Sanguíneas/métodos , Feminino , Veias Jugulares , Lactação , Glândulas Mamárias Animais/irrigação sanguínea , VeiasRESUMO
Feeding of neonates with artificial milk formulas is a popular trend toward early weaning of newborn dairy calves. These milk replacers (MR) should accelerate the rumen development, determining early solid feed intake and leading to better performances in cattle. Previous research demonstrated that sodium butyrate supplementation in MR can affect both small intestine and rumen development. Also acetate and propionate showed similar properties, while only a few studies indicate some potential benefit of monoglycerides on gut functions. The present study is aimed to determine the effect of the supplementation of a blend containing short and medium chain fatty acids monoglycerides (SMCFA) in milk replacer on rumen papillae development and growth performances in weaning calves. Twenty bull calves (about 2 weeks old, weighing around 43kg) were randomly allocated into two groups: control (C) and treated (T). Besides MR and starter diet, the latter offered at libitum, T calves received 0.2% SMCFA in MR. Animals were slaughtered after 56 days from the beginning of the trial. No difference was found between groups either in growth performances or in mean number of papillae/cm(2) of mucosa, total surface of papillae (mm(2))/cm(2) of mucosa or papillary size. In both groups, the morphology of the rumen epithelium was typical of parakeratosis. The cells of the stratum spinosum were directly transformed into swollen, ovoid, still nucleated keratinocytes, particularly at the papillary tip, probably as a result of unphysiological osmolarities caused by high concentrate intake. Degenerated squamous horn cells covered the "balloon like" cells forming several layers, particularly in the places of the rumen mucosa more protected from an abrasive action of solid feed. This was more evident in C animals. The squamous cells covering the papillary tip showed cytoplasmic protrusion, representing remains of the attachment sites of desmosomes, which increased the total absorptive surface and were more numerous and higher in T compared to C animals. It might be hypothesized that SMCFA supplementation in MR could better regulate epithelial cell proliferation and probably have an "emollient effect" leading to an easier "peeling" that might increase efficiency for nutrient transport across the epithelium.
Assuntos
Suplementos Nutricionais , Substitutos do Leite/administração & dosagem , Monoglicerídeos/administração & dosagem , Rúmen/efeitos dos fármacos , Rúmen/crescimento & desenvolvimento , Desmame , Administração Oral , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Animais , Animais Recém-Nascidos , Bovinos , Ácidos Graxos/administração & dosagem , Masculino , Substitutos do Leite/químicaRESUMO
Polynucleotide: adenosine glycosidases (PNAG) are a class of plant and bacterial enzymes commonly known as ribosome-inactivating proteins (RIP). They are presently classified as rRNA N-glycosidases in the enzyme nomenclature [EC 3.2.2.22]. Several activities on nucleic acids, other than depurination, have been attributed to PNAG: in particular modifications induced in circular plasmids, including linearisation and topological changes, and cleavage of guanidinic residues. Here we describe a chromatographic procedure to obtain nuclease-free PNAG by dye-chromatography onto Procion Red derivatized Sepharose((R)). Highly purified enzymes depurinate extensively pBR322 circular, supercoiled DNA at neutral pH and exhibit neither DNase nor DNA glycolyase activities, do not cause topological changes, and adenine is the only base released from DNA and rRNA, even at very high enzyme concentrations. A scanning force microscopy (SFM) study of pBR322 treated with saporin-S6 confirmed that (i) this PNAG binds extensively to the plasmid, (ii) the distribution of the bound saporin-S6 molecules along the DNA chain is markedly variable, (iii) plasmids already digested with saporin-S6 do not appear fragmented or topologically modified. The observations here described demonstrate that polynucleotide:adenosine glycosidase is the sole enzymatic activity of the four ribosome-inactivating proteins gelonin, momordin I, pokeweed antiviral protein from seeds and saporin-S6. These proteins belong to different families, suggesting that the findings here described may be generalized to all PNAG.
Assuntos
DNA/metabolismo , Imunotoxinas , N-Glicosil Hidrolases/isolamento & purificação , N-Glicosil Hidrolases/metabolismo , Cromatografia em Gel/métodos , Corantes , DNA Glicosilases , DNA Super-Helicoidal/metabolismo , Desoxirribonucleases/metabolismo , Concentração de Íons de Hidrogênio , Microscopia de Força Atômica , N-Glicosil Hidrolases/química , Proteínas de Plantas/metabolismo , Plasmídeos/metabolismo , Proteínas Inativadoras de Ribossomos , Proteínas Inativadoras de Ribossomos Tipo 1 , Proteínas Inativadoras de Ribossomos Tipo 2 , Saporinas , Sementes/química , SefaroseRESUMO
A study was carried out to evaluate the prevalence of bacteria of the Legionella genus in the water from the pools and showers of 12 swimming pools in the city of Bologna (Italy). Sampling took place four times for every establishment, once for each season of the year. Legionella spp. were found in 2 of the 48 pool water samples (L. micdadei and L. bozenanii) and in 27 of the 48 samples taken from the hot water of the showers: 19 were positive for L. pneumophila (10-19,250 cfu/l) and 18 for other species (20-6000 cfu/l). The contamination was seen to be consistent throughout the year, since the same species of legionellae were isolated at different samplings and in concentrations that did not reveal any seasonal trend. The legionellae and the Gram negative bacteria were not found in shower water with a temperature above 43 degrees C. However, in the samples of shower water with a lower temperature a statistically significant inverse correlation was seen between legionellae and Pseudomonas aeruginosa (r = -0.51; p<0.01) as well as between legionellae and Gram negative bacteria (r = -0.70; p<0.01). The potential risk of contracting infections from Legionella spp. in the swimming pool environment does not seem to be linked to the pool water, but to that of the showers. The water temperature of showers should therefore be maintained at a level high enough to prevent the reproduction of these bacteria.
Assuntos
Legionella , Piscinas , Monitoramento Ambiental , Dinâmica Populacional , Prevalência , Estações do Ano , Temperatura , Microbiologia da Água , Abastecimento de ÁguaRESUMO
The most prominent neuropathological and behavioral changes induced by trimethyltin (TMT) in different mammalian species were reviewed. From the analysis of the reported literature it becomes evident that the neuropathological effects are selectively present in the limbic system structures. In particular, the granular neurons of the fascia dentata and the pyramidal cells of the Ammon's horn are involved, with a different pattern of severity and extension according to the various species studied and to the dosage-schedule used. The neurological damage produced by TMT to several limbic structures is related to overt behavioral changes. TMT acute exposure in adult rats produces a remarkable behavioral syndrome, consisting in tremors, spontaneous seizures, tail mutilation, vocalization, hyper-reactivity and intra-specific aggression. Impairments in learning and memory processes are also induced following acute treatment. Specific behavioral changes in various species reflect the different sensitivity and vulnerability to the chemical compounds. In addition, prenatal and postnatal exposure induce long-term behavioral and neurological effects on developing central nervous system.
Assuntos
Comportamento/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Compostos de Trimetilestanho/efeitos adversos , Animais , Animais Recém-Nascidos , Comportamento Animal/efeitos dos fármacos , Encéfalo/embriologia , Encéfalo/patologia , Desenvolvimento Embrionário e Fetal/efeitos dos fármacos , Feminino , Hipocampo/efeitos dos fármacos , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Degeneração Neural/efeitos dos fármacos , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Primatas , Ratos , Compostos de Trimetilestanho/toxicidadeRESUMO
Lack of physical activity and obesity represent important public health problems. The objectives of the current study is to evaluate the effects of a counseling intervention (the PACE protocol) conducted by general practitioners and designed to motivate persons who are overweight or obese to increase their levels of physical activity. The counseling was offered 145 patients with a BMI > or =27 who were seen between May 2002 and April 2003 in the offices of 10 general practioners. The intervention, which lasted 3-5 minutes, was conducted during routine visits, based on the Prochaska-DiClemente model of behavioral change. Changes in the motivation of the patients to engage in physical activity and actual changes in levels of activity were measured, as were BMI and abdominal circumference. The median followup was 9 months. Among the 145 eligible patients, 103 (71%) agreed to particpate. Six months following the counselling, there was a significant change in both the motivational status and physical activity of the group, and they experienced significant decreases in BMI and abdominal circumference. Counseling using the PACE model appears to positively influence levels motivation and of physical activity in those patients who agreed to participate. Further studies should be conducted to evaluate the effectiveness of this strategy in other settings and the public health benefits of such counseling.
Assuntos
Aconselhamento , Exercício Físico , Promoção da Saúde , Obesidade/prevenção & controle , Adolescente , Adulto , Idoso , Índice de Massa Corporal , Medicina de Família e Comunidade , Feminino , Seguimentos , Comportamentos Relacionados com a Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Motivação , Atenção Primária à Saúde , Fatores de TempoRESUMO
An intraoral device has been experimented to stabilize oro-gastric or oro-jejunal feeding tubes in low birth weight newborns.