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1.
Data Brief ; 54: 110488, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38779409

RESUMO

The dataset described in this paper was constructed from 90 publications available from bibliographic databases. It presents the values of various quantitative components of ingestive behaviour of grazing ruminants (bite weight, biting rate, intake rate, grazing time, etc.). These values were coded according to the experimental factors tested and described in the publications, of a temporal nature (season, year, grazing cycle) or linked to the sward management strategies (overall density bulk or of the stems, the stage regrowth or the fertilization) or other pasture management strategies (herbage allowance, pasture access time, stocking rate). Other essential factors were also coded, specifying the characteristics of the grass grazed (height of the grass, apparent density, forage species), the characteristics of the animals used (species, stage, age and body weight) or the measurement methods of behavioural components. This coding process aims to facilitate the identification of subsets of data of interest, and have been analysed for example to highlight the main components determining bite weight or the components linking bite weight to intake rate and daily intake (see reference).

2.
Obes Surg ; 34(4): 1168-1173, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38372880

RESUMO

INTRODUCTION: Sleeve gastrectomy (SG) is an effective treatment for obesity in adolescents. The underlying weight loss mechanism may impact the peripheral and central gustatory system along with reward circuits in the brain. This study aims to assess changes in appetitive behavior in short-, medium-, and long-term follow-up. METHODS: In this prospective observational study, a total of 8 adolescents with obesity who underwent SG and 9 comparator unoperated participants were studied. Appetitive behaviour towards fat and sweet taste stimuli was assessed using the Progressive Ratio Task (PRT) over a 6 year period. RESULTS: Mean body mass index (BMI) of the surgical patients dropped from 51.5 ± 2.8 kg/m2 to 31.4 ± 1.9 and 30.9 ± 2.3 kg/m2 at 1 and 6 years follow-up, respectively. (p < 0.001). The median (interquartile range) total rewards earned during the PRT was 6 (5-7) pre-surgery, 5 (3-6) after one year and 4 (2-4) after six years from surgery (p = 0.007). CONCLUSION: SG reduced appetitive behaviour at 1 year with maintained the benefit over 6 years as measured by the progressive ratio task.


Assuntos
Obesidade Mórbida , Adolescente , Humanos , Obesidade Mórbida/cirurgia , Paladar , Obesidade/cirurgia , Resultado do Tratamento , Gastrectomia , Estudos Retrospectivos
3.
Trop Anim Health Prod ; 56(2): 53, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38261014

RESUMO

The study aimed to evaluate the inclusion effects of Stryphnodendron rotundifolium (barbatimão) extracts in substitution of the lasalocid sodium on the ingestive behaviour, intake, ruminal parameters, and digestibility of feedlot lambs. Twenty-four pantaneiro lambs were used, with an average age of 150 ± 4.59 days and an initial body weight of 21.2 ± 3.63 kg. The lambs were distributed in three treatments in an experimental design with randomized blocks. The treatments correspond to the additive supplements: LAS (0.019 g of lasalocid sodium/lamb/d); DGB (1.50 g of barbatimão dried ground bark/lamb/d); DHE (0.30 g of barbatimão dry hydroalcoholic extract/lamb/d). The DHE increased 59.74 min in the time spent for ingestion per day, resulting in an efficiency reduction of dry matter (DM) ingestion (127 g of DM/h of feed). There was a reduction of 1.8 mg/dL in the ammoniacal nitrogen concentration with extract supplementation compared to LAS. The DGB reduced total volatile fatty acids by 48.9% compared to the control treatment. The inclusion of barbatimão extracts (DGB and DHE) reduced 12.05% of ruminal butyrate content. The supplementation of barbatimão extracts replacing lasalocid sodium in the diet of feedlot lambs did not affect intake and caused small changes on ingestive behaviour.


Assuntos
Fabaceae , Lasalocida , Ovinos , Animais , Casca de Planta , Carneiro Doméstico , Extratos Vegetais/farmacologia , Sódio
4.
Diabetes Obes Metab ; 25(3): 856-877, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36495318

RESUMO

OBJECTIVES: Oxytocin (OT) has a well-established role in reproductive behaviours; however, it recently emerged as an important regulator of energy homeostasis. In addition to central nervous system (CNS), OT is found in the plasma and OT receptors (OT-R) are found in peripheral tissues relevant to energy balance regulation. Here, we aim to determine whether peripheral OT-R activation is sufficient to alter energy intake and expenditure. METHODS AND RESULTS: We first show that systemic OT potently reduced food intake and food-motivated behaviour for a high-fat reward in male and female rats. As it is plausible that peripherally, intraperitoneally (IP) injected OT crosses the blood-brain barrier (BBB) to produce some of the metabolic effects within the CNS, we screened, with a novel fluorescently labelled-OT (fAF546-OT, Roxy), for the presence of IP-injected Roxy in CNS tissue relevant to feeding control and compared such with BBB-impermeable fluorescent OT-B12 (fCy5-OT-B12; BRoxy). While Roxy did penetrate the CNS, BRoxy did not. To evaluate the behavioural and thermoregulatory impact of exclusive activation of peripheral OT-R, we generated a novel BBB-impermeable OT (OT-B12 ), with equipotent binding at OT-R in vitro. In vivo, IP-injected OT and OT-B12 were equipotent at food intake suppression in rats of both sexes, suggesting that peripheral OT acts on peripheral OT-R to reduce feeding behaviour. Importantly, OT induced a potent conditioned taste avoidance, indistinguishable from that induced by LiCl, when applied peripherally. Remarkably, and in contrast to OT, OT-B12 did not induce any conditioned taste avoidance. Limiting the CNS entry of OT also resulted in a dose-dependent reduction of emesis in male shrews. While both OT and OT-B12 proved to have similar effects on body temperature, only OT resulted in home-cage locomotor depression. CONCLUSIONS: Together our data indicate that limiting systemic OT CNS penetrance preserves the anorexic effects of the peptide and reduces the clinically undesired side effects of OT: emesis, taste avoidance and locomotor depression. Thus, therapeutic targeting of peripheral OT-R may be a viable strategy to achieve appetite suppression with better patient outcomes.


Assuntos
Ingestão de Alimentos , Ocitocina , Ratos , Masculino , Feminino , Animais , Ocitocina/farmacologia , Motivação , Paladar , Sistema Nervoso Central , Vômito
5.
Animal ; 15(9): 100336, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34371468

RESUMO

Many of the studies in Campos grasslands focus on management aspects such as the control of herbage allowance, and application of nutrients and/or overseeding with legumes. However, there is little literature on how the Campos grassland resource is utilised, especially regarding the grazing pattern and the relationship between pasture quantity and quality on daily grazing activities. The study of the ingestive behaviour in species-rich and heterogeneous native grasslands during daylight hours, and understanding how animals prioritise quality or quantity of intake in relation to pasture attributes, are important to comprehend the ingestive-digestive processes modulating the energy intake of animals and to achieve a better grazing management. Therefore, the objective was to describe and quantify the daily grazing behaviour of growing cattle grazing native pasture with different structures as a result of different management practices, and study the relationship of pasture attributes and intake through multivariate analysis. The study was carried out at the Faculty of Agronomy, Paysandú, Uruguay. Treatments were native grassland, overseeding with Trifolium pratense and Lotus tenuis + phosphorus, and native pasture + nitrogen-phosphorus. Grazing activities were discriminated into grazing, searching (defined when animals take 1-2 bites in one feeding station and then change to another feeding station and so on), ruminating and idling. The probability of time allocated to each activity was continuously measured during daylight hours (0700-1930) and was related to pasture structure and forage quality using regression tree models, while the bite rate was determined every 2 h. The diurnal pattern of growing cattle showed grazing and searching sessions, followed by ruminating and idling sessions. The length of sessions (as the probability of time allocated to each activity) varied throughout the day. The grazing probability was greater during afternoon than morning and midday (0.74 vs 0.45 vs 0.46, respectively), and it was associated with higher bite rate (34.2 bites/min). Regression tree models showed different grazing, searching and ruminating strategies according to pasture attributes. During the morning, animals modified grazing, searching, ruminating and idling strategies according to bite rate, crude protein in diet and herbage allowance. At midday, they only adjusted ruminating and idling, while during afternoon sessions, grazing activities were modified by pasture quantity attributes such as herbage mass and herbage allowance. By controlling the herbage allowance, herbage mass and pasture height, animals prioritise quality in the morning and quantity in the afternoon, integrating and modifying the grazing-searching and ruminating-idling pattern.


Assuntos
Comportamento Alimentar , Pradaria , Ração Animal/análise , Animais , Bovinos , Dieta/veterinária , Ingestão de Alimentos , Feminino , Lactação
6.
Nutrients ; 12(9)2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32899675

RESUMO

Taste hedonics drive food choices, and food choices affect weight maintenance. Despite this, the idea that hyper-palatability of sweet foods is linked to obesity development has been controversial for decades. Here, we investigate whether interpersonal differences in sweet-liking are related to body composition. Healthy adults aged 18-34 years from the UK (n = 148) and the US (n = 126) completed laboratory-based sensory tests (sucrose taste tests) and anthropometric measures (body mass index; BMI, body fat; fat-free mass; FFM, waist/hips circumferences). Habitual beverage intake and lifestyle and behavioural characteristics were also assessed. Using hierarchical cluster analysis, we classified participants into three phenotypes: sweet liker (SL), sweet disliker (SD), and inverted-U (liking for moderate sweetness). Being a SD was linked to higher body fat among those younger than 21 years old, while in the older group, SLs had the highest BMI and FFM; age groups reflected different levels of exposure to the obesogenic environment. FFM emerged as a better predictor of sweet-liking than BMI and body fat. In the older group, sweetened beverage intake partially explained the phenotype-anthropometry associations. Collectively, our findings implicate underlying energy needs as an explanation for the variation in sweet-liking; the moderating roles of age and obesogenic environment require additional consideration.


Assuntos
Fatores Etários , Composição Corporal , Açúcares da Dieta/análise , Preferências Alimentares/fisiologia , Paladar , Tecido Adiposo , Adolescente , Adulto , Antropometria , Índice de Massa Corporal , Análise por Conglomerados , Feminino , Voluntários Saudáveis , Humanos , Estilo de Vida , Masculino , Obesidade/psicologia , Filosofia , Adulto Jovem
7.
Animal ; 14(11): 2288-2297, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32381153

RESUMO

Breeding values for feed intake and feed efficiency in beef cattle are generally derived indoors on high-concentrate (HC) diets. Within temperate regions of north-western Europe, however, the majority of a growing beef animal's lifetime dietary intake comes from grazed grass and grass silage. Using 97 growing beef cattle, the objective of the current study was to assess the repeatability of both feed intake and feed efficiency across 3 successive dietary test periods comprising grass silage plus concentrates (S+C), grazed grass (GRZ) and a HC diet. Individual DM intake (DMI), DMI/kg BW and feed efficiency-related parameters, residual feed intake (RFI) and gain to feed ratio (G : F) were assessed. There was a significant correlation for DMI between the S+C and GRZ periods (r = 0.32; P < 0.01) as well as between the S+C and HC periods (r = 0.41; P < 0.001), whereas there was no association for DMI between the GRZ and HC periods. There was a significant correlation for DMI/kg BW between the S+C and GRZ periods (r = 0.33; P < 0.01) and between the S+C and HC periods (r = 0.40; P < 0.001), but there was no association for the trait between the GRZ and HC periods. There was a significant correlation for RFI between the S+C and GRZ periods (r = 0.25; P < 0.05) as well as between S+C and HC periods (r = 0.25; P < 0.05), whereas there was no association for RFI between the GRZ and HC periods. Gain to feed ratio was not correlated between any of the test periods. A secondary aspect of the study demonstrated that traits recorded in the GRZ period relating to grazing bite rate, the number of daily grazing bouts and ruminating bouts were associated with DMI (r = 0.28 to 0.42; P < 0.05 - 0.001), DMI/kg BW (r = 0.36 to 0.45; P < 0.01 - 0.001) and RFI (r = 0.31 to 0.42; P < 0.05 - 0.001). Additionally, the number of ruminating boli produced per day and per ruminating bout were associated with G : F (r = 0.28 and 0.26, respectively; P < 0.05). Results from this study demonstrate that evaluating animals for both feed intake and feed efficiency indoors on HC diets may not reflect their phenotypic performance when consuming conserved forage-based diets indoors or when grazing pasture.


Assuntos
Poaceae , Silagem , Ração Animal/análise , Animais , Bovinos , Dieta/veterinária , Ingestão de Alimentos , Europa (Continente) , Comportamento Alimentar , Silagem/análise
8.
R Soc Open Sci ; 7(2): 191338, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32257311

RESUMO

Animals fed a Western-style diet (WS-diet) demonstrate rapid impairments in hippocampal function and poorer appetitive control. We examined if this also occurs in humans. One-hundred and ten healthy lean adults were randomized to either a one-week WS-diet intervention or a habitual-diet control group. Measures of hippocampal-dependent learning and memory (HDLM) and of appetitive control were obtained pre- and post-intervention. HDLM was retested at three-week follow-up. Relative to controls, HDLM performance declined in the WS-diet group (d = 0.43), but was not different at follow-up. Appetitive control also declined in the WS-diet group (d = 0.47) and this was strongly correlated with HDLM decline (d = 1.01). These findings demonstrate that a WS-diet can rapidly impair appetitive control in humans-an effect that could promote overeating in consumers of a WS-diet. The study also suggests a functional role for the hippocampus in appetitive control and provides new evidence for the adverse neurocognitive effects of a WS-diet.

9.
Trends Cogn Sci ; 23(4): 349-361, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30824229

RESUMO

In the modern obesogenic environment, limiting calorie-dense food consumption is partially dependent on the capacity of individuals to override visceral reactions to hyperpalatable and rewarding food cues. In the current review, we employ a health neuroscience framework to outline: (i) how individual variations in prefrontal cortical structure and functionality, and by extension, executive functions, may predispose an individual to the overconsumption of appetitive calorie-dense foods via differences in dietary self-regulation; (ii) how obesity may result in changes to cortical structure and functionality; and (iii) how the relationship between the structure and function of the prefrontal cortex and obesity may be best described as reciprocal in nature.


Assuntos
Função Executiva , Comportamento Alimentar , Obesidade , Córtex Pré-Frontal , Autocontrole , Função Executiva/fisiologia , Comportamento Alimentar/fisiologia , Humanos , Neurociências , Obesidade/etiologia , Obesidade/fisiopatologia , Córtex Pré-Frontal/anatomia & histologia , Córtex Pré-Frontal/fisiologia
10.
Trop Anim Health Prod ; 51(6): 1717-1723, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30919319

RESUMO

The objective of this study was to evaluate the effect of the substitution of Tifton 85 hay (Cynodon spp.) with spineless cactus (Nopalea cochenillifera) on the intake, digestibility of nutrients and ingestive behaviour of sheep. Eight rumen-cannulated sheep were used, with an average body weight of 58.44 ± 13.5 kg. The treatments consisted of the replacement of Tifton 85 hay with cactus at levels of 0, 333, 666 and 1000 g/kg. Samples of food and leftovers were collected at the beginning of each trial period. Digestibility was estimated using indigestible acid detergent fibre. Ingestive behaviour was evaluated via scan sampling. The replacement of Tifton 85 hay with spineless cactus had a significant effect (P < 0.05) on the intake and digestibility of neutral detergent fibre and non-fibre carbohydrates. The rumination efficiency of neutral detergent fibre was not affected (P > 0.05) by the substitution of Tifton 85 hay with spineless cactus. However, plasma glucose, phosphorus and magnesium were linearly influenced by Tifton 85 hay replacement with spineless cactus. Therefore, spineless cactus can be used to replace up to 500 g/kg of Tifton 85 hay in complete diets for sheep.


Assuntos
Ração Animal/análise , Cactaceae , Dieta/veterinária , Digestão/fisiologia , Ovinos/metabolismo , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , Animais , Peso Corporal , Fibras na Dieta/metabolismo , Metabolismo Energético , Comportamento Alimentar , Rúmen/metabolismo
11.
Animal ; 13(1): 127-135, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29731001

RESUMO

The timing in which supplements are provided in grazing systems can affect dry matter (DM) intake and productive performance. The objective of this study was to evaluate the effect of timing of corn silage supplementation on ingestive behaviour, DM intake, milk yield and composition in grazing dairy cows. In total, 33 Holstein dairy cows in a randomized block design grazed on a second-year mixed grass-legume pasture from 0900 to 1500 h and received 2.7 kg of a commercial supplement at each milking. Paddock sizes were adjusted to provide a daily herbage allowance of 15 kg DM/cow determined at ground level. The three treatments imposed each provided 3.8 kg DM/day of corn silage offered in a single meal at 0800 h (Treatment AM), equally distributed in two meals 0800 and 1700 h (Treatment AM-PM) or a single meal at 1700 h (Treatment PM). The experiment was carried out during the late autumn and early winter period, with 1 week of adaptation and 6 weeks of measurements. There were no differences between treatments in milk yield, but 4% fat-corrected milk yield tended to be greater in AM-PM than in AM cows, which did not differ from PM (23.7, 25.3 and 24.6±0.84 kg/day for AM, AM-PM and PM, respectively). Fat percentage and yield were greater for AM-PM than for AM cows and intermediate for PM cows (3.89 v. 3.66±0.072% and 1.00 v. 0.92±0.035 kg/day, respectively). Offering corn silage in two meals had an effect on herbage DM intake which was greater for AM-PM than AM cows and was intermediate in PM cows (8.5, 11.0 and 10.3±0.68 kg/day for AM, AM-PM and PM, respectively). During the 6-h period at pasture, the overall proportion of observations on which cows were grazing tended to be different between treatments and a clear grazing pattern along the grazing session (1-h observation period) was identified. During the time at pasture, the proportion of observations during which cows ruminated was positively correlated with the DM intake of corn silage immediately before turn out to pasture. The treatment effects on herbage DM intake did not sufficiently explain differences in productive performance. This suggests that the timing of the corn silage supplementation affected rumen kinetics and likewise the appearance of hunger and satiety signals as indicated by observed changes in temporal patterns of grazing and ruminating activities.


Assuntos
Criação de Animais Domésticos/métodos , Bovinos/fisiologia , Comportamento Alimentar , Silagem/análise , Animais , Dieta/veterinária , Suplementos Nutricionais/análise , Feminino , Distribuição Aleatória , Fatores de Tempo , Zea mays/química
12.
J Anim Physiol Anim Nutr (Berl) ; 102(5): 1120-1130, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29907969

RESUMO

Due to seasonal changes in the quality and quantity of herbage, the nutrient supply to grazing dairy cows is not always sufficient, which may increase their metabolic load. To investigate the temporal pattern of behavioural changes in relation to concomitant metabolic alterations, we subjected 15 multiparous early lactating Holstein dairy cows (24 (SD 7.4) days in milk) to a short-term metabolic challenge, which we provoked by abruptly withdrawing concentrate for 1 week. Cows grazed full-time and were supplemented with concentrate in experimental week (EW) 1 and EW 3, whereas concentrate was withdrawn in EW 2. We analysed milk and blood samples to characterise the metabolic changes and found that the total yield of milk and protein decreased (p < 0.05) and fat yield, fat-to-protein ratio and acetone content increased (p < 0.05) from EW 1 to EW 2. Plasma glucose and insulin concentrations were lower (p < 0.05), and concentrations of nonesterified fatty acids and beta-hydroxybutyrate were higher (p < 0.05) in EW 2 compared with EW 1. Apart from ingestive and rumination behaviour and activity, we also monitored the use of an automated brush on pasture. While time spent eating and ruminating increased (p < 0.05) in EW 2 compared with EW 1, time spent idling decreased (p < 0.05). Concomitantly, while time standing and moving increased (p < 0.05) from EW 1 to EW 2, walking time decreased (p < 0.05). The daily proportion of cows using the automated brush decreased (p < 0.05) in EW 2 compared with EW 1, as did the duration of brushing per day. In conclusion, grazing cows experiencing a metabolic challenge try to compensate for the nutrient deficiency by increasing eating time, a behavioural element important for short-term survival. Due to the strong impact of weather conditions, we cannot currently recommend observation of outdoor brushing activity to address short-term alterations in the metabolic state of grazing cows.


Assuntos
Criação de Animais Domésticos/métodos , Bovinos/metabolismo , Comportamento Alimentar , Lactação/metabolismo , Poaceae/metabolismo , Animais , Dieta , Suplementos Nutricionais , Ingestão de Alimentos , Feminino , Leite , Estações do Ano
13.
Ciênc. rural ; 46(9): 1662-1667, tab, graf
Artigo em Inglês | LILACS | ID: lil-787391

RESUMO

ABSTRACT: The experiment was carried out to identify changes in the behaviorr of lactating cows induced by severe feeding restriction and further refeeding that could serve as facilitators for the visual identification of cows more prone to produce milk with reduced stability. Twelve cows were separated into two groups: Control: full diet supply; Restriction: 50% of the full diet. Feed restriction lasted seven days (Period 1), with posterior supply of full diet for seven days (Period 2) for all treatments. Behavior was observed on the first and fifth days in each period from 08h40 to 19h00. Ingestive and social behavior were monitored. Cortisol assessed stress levels. Analysis of variance and multifactorial statistical analyzes were performed. Adequate feed supply reduced stress, improved animals' welfare and milk stability to the ethanol test. Elevation in the incidence of behavior related with hunger, frustration and discomfort is an indicator of cows more prone to produce milk with reduced stability.


RESUMO: O experimento foi conduzido para identificar alterações comportamentais de vacas lactantes submetidas à restrição alimentar severa e realimentação, as quais podem servir para identificação visual de vacas mais propensas a produzir leite de reduzida estabilidade ao álcool. Doze vacas foram separadas em dois grupos: controle: suprimento de dieta completa; restrição: 50% da dieta completa. A restrição alimentar durou sete dias (Período 1), com posterior suprimento de dieta completa por sete dias (Período 2) a todos os animais. O comportamento foi monitorado no primeiro e quinto dias de cada período, entre as 08h40min e 19h. Comportamentos ingestivo e social foram observados. Os níveis de cortisol foram utilizados para monitorar os níveis de estresse. Análises de variância e multifatorial foram realizadas. O suprimento adequado da dieta reduziu estresse, aumentou o bem-estar animal, bem como a estabilidade do leite ao teste do álcool. Elevação na incidência de comportamentos relacionados à fome, frustração e desconforto é um indicador de vacas mais propensas a produzir leite com reduzida estabilidade.

14.
Trop Anim Health Prod ; 48(3): 539-44, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26739344

RESUMO

The aim of this study was to evaluate the effects of replacing Tifton-85 hay (0, 20, 40, 60 and 80 % on a dry matter basis) with water hyacinth hay (Eichhornia crassipes) on intake and digestibility of nutrients, feeding behaviour, rumen and blood parameters of sheep. Five uncastrated male sheep, cannulated in the rumen, with an average body weight of 40 kg were assigned in a 5 × 5 Latin square design. The water hyacinth hay contained 870 g/kg dry matter (DM), 159 g/kg crude protein (CP), 547 g/kg neutral detergent fibre (NDF) and 461 g/kg total digestible nutrients (TDN). The DM intake and digestibility of NDF and non-fibre carbohydrates (NFC) were linearly reduced by replacing the Tifton-85 hay with water hyacinth hay. Similarly, there was a linear reduction of rumination time and efficiencies of feeding and rumination of DM and NDF. The concentrations of urea, glucose, AST and GGT in blood plasma were not changed by replacing the Tifton-85 hay with water hyacinth hay. Although water hyacinth hay reduced the intake and digestibility of some nutrients, the Tifton-85 hay replacement could be economically advantageous for sheep feeding.


Assuntos
Ração Animal/análise , Criação de Animais Domésticos , Dieta/veterinária , Eichhornia , Ovinos/fisiologia , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , Animais , Peso Corporal , Fibras na Dieta/metabolismo , Digestão , Masculino , Rúmen/metabolismo
15.
Ciênc. rural ; 41(11): 2010-2013, nov. 2011. ilus
Artigo em Inglês | LILACS | ID: lil-608034

RESUMO

The aim of this study was describe the relationship between grazing time and herbage intake and identify tools to grazing management of dairy cows grazing Italian ryegrass (Lolium multiflorum Lam.) on a rotational grazing method. Six dairy cows in mid-lactation period were allowed to graze paddocks during three grazing cycles. During each cycle cows grazed two paddocks with 9 days of occupation by paddock and an herbage allowance of 30kg DM cow-1 day-1. Measurements were made in the last 9 days of each period and during intervals between cycles cows grazed an adjacent area with a mixed of temperate species. It was compared three grazing cycles and cows eating similar herbage amount with different daily grazing time. Independently of herbage intake, daily grazing time increased 12min by cm of the reduction on leaf height. Reductions on efficiency to graze are clearly associated to structural traits of canopy as proximity to ground level and stems + pseudo-stems content on the graze layer. In conclusion, under rotational grazing, daily grazing time is strongly associated with leaf height in the grazing layer, but it is not a good indicator of DM herbage intake. Structural traits of canopy are clearly associated with efficiency to graze, independently of daily herbage intake.


Objetivou-se descrever a relação entre o tempo de pastejo e o consumo de forragem e identificar possíveis indicadores de manejo para vacas leiteiras em pastos de azevém (Lolium multiflorum Lam.) no método rotativo. Foram utilizadas seis vacas leiteiras no terço médio de lactação durante três ciclos de pastejo. Em cada ciclo, os animais tiveram acesso a dois piquetes com nove dias de ocupação e oferta de forragem de 30kg MS vaca-1 dia-1. As medidas foram realizadas nos últimos nove dias de cada ciclo e, nos intervalos entre ciclos, os animais permaneceram em área adjacente com acesso a uma mistura de espécies forrageiras de clima temperado. Comparando os três ciclos, foi possível observar que as vacas obtiveram semelhante consumo de forragem com diferentes tempos de pastejo diário. Independente da quantidade de forragem ingerida, o tempo de pastejo diário aumentou 12min por cm de redução na altura residual de lâminas foliares e reduções na eficiência de pastejo foram claramente associadas a características estruturais da pastagem, como, a proximidade ao solo e a proporção de colmos + pseudocolmos no estrato pastejado. Em conclusão, sob pastejo rotativo, o tempo de pastejo está intimamente associado com a altura residual de folhas, mas não é um bom indicador do consumo de forragem. As características estruturais do pasto são claramente associadas à eficiência de pastejo, independente do consumo diário de forragem.

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