Animal - Open Space最新文献

Negative energy balance (NEB) in high-yielding cows during the peripartum period raises the risk of postpartum diseases. High-level concentration of non-esterified fatty acid (NEFA) is a good indicator of excessive NEB. The current low-cost and high-throughput mid-infrared (MIR) spectroscopy method is gradually applied to predict NEFA concentrations for NEB identification. The objective of this study was to compare different pre-processing methods and analysis models for optimal predictions of serum NEFA using milk MIR spectra. Four spectral pre-processing methods: standard normal variate, first-order derivative (FD), second-order derivative, and Savitzky-Golsy convolution smoothing, and four prediction models: partial least squares regression, ridge regression, lasso regression (LassoR), and random forest regression were investigated. In total, 366 collected serum and milk samples within the 1–7 weeks postpartum were randomly divided into the training (70%) and test (30%) sets for cross-validations. The results showed that the combined strategy of FD-LassoR model when parity and days in lactation information were considered resulted in the highest R² = 0.643, RMSE = 0.153 mmol/L, and highest residual predictive deviation = 1.665 of predictions on the test set. In addition, R² and RMSE values of FD-LassoR combined with other information were still higher than the other four prediction scenarios. Therefore, our study enables the optimal prediction of serum NEFA concentrations using milk MIR spectra in the further research and practical applications.

Collection of blood samples by venipuncture requires isolation, restraint and immobilisation, which is stressful for piglets and may result in unreliable readings. A jugular vein catheter allows frequent blood sampling with minimal stress to the piglets. Techniques for jugular vein catheter implantation in older pigs have been described, but less information is available for suckling piglets. This report describes the procedure of catheter implantation into an external jugular vein for longer-term frequent blood sampling in 48 12-day (d)-old suckling German Landrace piglets with a mean BW of 3.4 ± 0.7 kg. Catheterisation was performed either under general anaesthesia by injection of azaperone and ketamine (a/k) or by inhalation of isoflurane (IsoF). To determine the optimal incision site in the sulcus jugularis, the centre between the caudal edge of the mandibula, cranial shoulder and sternum was identified. After a small incision of the skin, the jugular vein was bluntly dissected and a catheter was inserted. The tip of the catheter was placed near the beginning of the right atrium. After wound closure, the surgical area was secured by disinfection and bandages. The piglets were returned to their littermates in the farrowing pen immediately after full recovery from anaesthesia, which was 5–7 h in a/k and 0.75 h in IsoF anaesthetised piglets after the onset of the surgery, respectively. The catheter was flushed daily with 0.9% NaCl-0.1% sodium citrate solution. To demonstrate the longer-term benefits of the catheter, on d 4 after surgery, a series of frequent blood sampling were performed after an oral xylose bolus. In total, 10 samples of 0.5 mL were taken before and every 30 min after the oral xylose bolus for 5 h; the blood volume was replaced with 0.9% NaCl solution. On d 4 after surgery, 41 of 48 implanted catheters were considered fully functional (90% of desired samples collected), three as partially functional, and four as non-functional, whereas two catheters were non-functional already from d 1 after surgery. The catheterised animals remained clinically healthy but showed less daily BW gain from age d 12 (day of surgery) to d 15 than non-catheterised control animals (0.12 ± 0.01 vs 0.23 ± 0.01 kg; n = 46; P < 0.05). In conclusion, the catheter implanted into an external jugular vein in 12-d-old suckling piglets remaining with the sow was patent for 4 d after surgery and allowed frequent blood sampling with minimal stress for the piglets.

Mechanistic models are valuable tools for studying the underlying mechanisms of complex biological phenomena. For example, cow lifespan models can be used to identify differences in resource acquisition and allocation strategies between individuals, which is relevant for decision-making in breeding programs. In such models, differences in simulated traits between individuals are consequences of the parameter set that represents the genetic potential of each animal and its interaction with the environment. This indicates that the identification of these differences is essentially a search for individual parameters. In mechanistic models, this search is generally a non-convex problem that has different local minima because the parameters interact within these models. Due to this and to the simulation time length (e.g. years), there is uncertainty associated with the inference of the parameter values for each individual. This uncertainty can be quantified using Bayesian inference since this approach treats the model parameters as random variables with an underlying probability distribution that describes them. The objective of this work was to employ the Delayed Rejection Adaptive Metropolis (DRAM) algorithm to identify the parameters of a cows’ lifespan model using two datasets of Holstein cows. The datasets contain periodic measurements of Milk Yield (MY), BW, and Body Condition Score (BCS). Additionally, one of the two datasets has information of BW from birth to first calving. The average Mean Absolute Percentage Error (MAPE) minimisation between the simulated and experimental data (MY, BW and BCS) was used as the objective function for parameter search. The Bayesian inference performance was compared with four optimisation metaheuristic approaches: Differential Evolution, Genetic Algorithm, Particle Swarm Optimisation, and Simulated Annealing. Although the results show that all methods are efficient in finding parameter values that reduce the distance between the simulated and experimental data (MAPE < 10%), the DRAM method is more efficient in terms of computational cost, and the parameter distributions obtained with this method offer more information about the statistical properties of each parameter (e.g. median).

Enteric methane (CH₄) emissions are a major contributor to global greenhouse gas emissions. A number of different CH₄ mitigation strategies have been proposed, and the inclusion of alternative forages into grazing systems could be a practical and feasible option. Multispecies swards comprise a mixture of forage species and can increase grassland productivity, reduce nitrogen fertiliser requirements, and reduce fertiliser-associated nitrous oxide emissions. This study investigated the potential benefit of multispecies swards in reducing ruminal CH₄ production. Using the in vitro rumen simulation technique, we compared the effects of different forages (perennial ryegrass, timothy, red clover, white clover, chicory, ribwort plantain and their equi-proportional mixture) on CH₄ and gas production, ruminal fermentation parameters and nutrient digestibility. We also compared these responses to perennial ryegrass produced with a higher nitrogen application rate (300 N). The experiment was conducted over 21 d, with the initial 14 d allowed for dietary adaptation. Over the subsequent 7 d, there were significant effects of forage type on CH₄ production, ruminal fermentation and digestibility. Ribwort plantain, chicory and white clover showed lower CH₄ production; with chicory producing 73% and 57% less CH₄ (mmol d⁻¹) compared to 300 N perennial ryegrass and 150 N perennial ryegrass incubation, respectively. Chicory had 72% lower CH₄ produced per gram of organic matter digested (mmol g⁻¹) than that of 300 N perennial ryegrass. Chicory and 300 N perennial ryegrass had greater (P < 0.01) organic matter and nutrient digestibility (DM, CP, NDF, and ADF) than other forages. Greater ammonia nitrogen concentration was observed in chicory and both clover species, compared to the other forage species (P < 0.01). In general, the response of the six-species mixture was not significantly different to the average response of the six component monocultures. Thus, from these data, the performance of multispecies swards for these responses (in general) was predictable from the performance of the component monocultures. These results showed that different grassland forages, especially chicory and white clover, have the potential to reduce ruminal CH₄ emissions and could be a promising anti-methanogenic alternative to chemical CH₄ inhibitors and feed additives. More generally, the relatively wide variation in CH₄ abatement potential across a small sample of plant species suggests the merit of wider screening to identify grassland species with high CH₄ abatement potential in vitro.

Intensive animal production is facing a crisis of legitimacy linked to its contribution to pollution, biohazard risks, and animal suffering. With almost 97% of the production coming from intensive systems, rabbit farming is questioned. Similarly, the plant sector is under scrutiny linked to a high input dependency. Among the alternatives, organic farming and agroforestry systems (associating trees and animals) may contribute to a more sustainable agriculture. However, a number of elements should be evaluated when designing agroforestry systems, especially innovative systems with no previous references. Here, we describe the process of designing an agroforestry system combining rabbits and apple trees. We used an incremental process over three rounds of prototyping (P1, P2 and P3) to develop, refine and adapt a rabbit housing system to an apple orchard. Lessons learned from multiple measurements (thermal comfort, rabbit growth, etc.) and professional feedback (during a workshop) helped to create a functional system. The P1 focused on the design of two outdoor housing systems (mobile-cage vs fixed-pen) inspired by organic rabbit farming practices. Both housing protected the animals from extreme temperatures. However, the main lesson learnt from P1 is the necessity to vaccinate animals to prevent viral diseases. The aim of P2 was to evaluate the feasibility of installing the P1 housing in an apple orchard and to expose it to the observations and comments of professionals during a workshop. On the basis of the experimental observations and the feedback from professionals, the preference was for the fixed-pen over the mobile-cage. The fixed-pen, as opposed to the mobile-cage, allowed the rabbits to graze near the apple tree trunks, where the cleaning services were observed. However, participants questioned the fencing of the fixed-pen. They found it difficult to install and/or dismantle. Based on their comments, the P3 fences were designed to be lightweight and easy to handle. As grazing accounted for about 28% of the rabbits’ activities, and 12 rabbits were able to graze 25.5 m² of herbage in less than 10 days (P2), the new fencing allowed the fixed-pen to be converted into a mobile-pen. In short, rabbits provide an effective weeding service for the orchard, while benefiting from its microclimate, food resources and living environment, which enhances their well-being. This association was easier to implement in autumn (P2) than in spring (P3), the season of intensive orchard work. In short, this association is feasible and seems to be easily adaptable by farmers.

The aim of the current trial was to study the impact of a high somatic cell count (SCC) on milk volatilome of fresh raw milk, and its evolution during storage of processed fluid milk. Six Holstein cows were selected from our research dairy herd based on test-day SCC records. Three cows were used to produce low-SCC milk (20 × 10³ cells/mL). The three other cows had one-quarter infected by Staphylococcus aureus. Infected and healthy udder halves were milked separately, and high-SCC milk was standardized to 400 × 10³ cells/mL by mixing these two milks. The profile of milk volatile organic compounds (VOCs) was determined on raw milk and during the storage of processed milk. The processing included a standardization to 3.25% fat, followed by homogenization, and thermization (65 °C/30 min). This procedure was repeated four times over a period of 7 days. A total of 40 VOC were identified using the solid-phase microextraction technique followed by gas chromatography separation, mass spectrometry analysis, and database search. These VOC were grouped into seven different families, including alcohols (n = 4), free fatty acids (n = 5), sulfur compounds (n = 3), esters (n = 7), ketones (n = 7), aldehydes (n = 12), and aromatic hydrocarbons (n = 2). In raw milk, high SCC was associated with a tendency for lower concentrations of ethyl-hexanoate (P = 0.07), acetone (P = 0.06), and benzaldehyde (P = 0.07) and lower concentrations of trans-2 hexenal (P = 0.04). On the contrary, high SCC was associated with a tendency for greater concentrations of acetic acid (P = 0.09) and hexanoic acid (P = 0.07) and greater concentrations of 2-nonanone (P = 0.02) and pentanal (P = 0.01). Concentrations of most VOC increased during the storage of processed milk. Lower concentrations of butanoic acid (P = 0.09; tendency) and ethyl hexanoate (P = 0.04), and greater concentration of 1-ocen-3-ol (P < 0.01) were observed in high-SCC milk at all times of storage evaluated. Increases in concentrations over time were less pronounced for ethanol (P < 0.01), ethyl butanoate (P = 0.05), and propanal (P = 0.10) in high SCC as compared with low SCC milk. In conclusion, an increase in SCC has a limited effect on milk volatilome, when a SCC standard of 400 × 10³ cells/mL for bulk milk is respected.

Nitrogen pollution is an important issue in modern agriculture. For the dairy industry, increasing the efficiency of milk protein production may reduce the environmental impact of commercial farms. Optimal N utilization can be achieved by combining forage and concentrate varying in their degradability in the rumen. The aim of this study was to gain insight into the fate of dietary N as affected by forage type and rumen-degradable protein supply in lactating dairy cows, with an emphasis on milk N efficiency. Four rumen-fistulated Holstein cows were used in a 4 × 4 Latin square design balanced for residual effects. Four treatments consisting of a 2-by-2 factorial arrangement of alfalfa silage (AL) or red clover (RC)-based diets designed to satisfy 100 (rumen-degradable protein (RDP)-100) or 85% (RDP-85) of rumen degradable protein demand, by varying the amounts of ground and steam-flaked corn grain, as well as non-treated and heat-treated soybean meals. Dietary CP concentrations were greater in diets based on AL as compared with RC (P < 0.01). Kinetics of in sacco N disappearance revealed that the rapidly disappearing fraction was lower with RC than with AL diets, and this difference tended to be more pronounced for RDP-85 than RDP-100 (interaction, P = 0.06). On the contrary, slowly disappearing N fraction and fractional rate of disappearance were greater for RC as compared with AL diets (P < 0.01). Reducing RDP from 100 to 85% of requirements increased the slowly disappearing N fraction, but decreased the rapidly disappearing fraction and the fractional rate of disappearance of N (P < 0.01). Intakes of DM and N were lesser with RC compared with AL, and these differences were more pronounced with RDP-85 than with RDP-100 (interaction, P ≤ 0.04). As a proportion of N intake, fecal excretion tended to be greater (P = 0.09), whereas urinary excretion was lower (P = 0.04) with RC than with AL diets. Milk yield (tendency; P = 0.07) and total N secreted in milk were reduced (P < 0.01) with RC compared with AL diets. Feeding RC increased milk N efficiency (g of milk N/ kg of N intake) as compared with AL, and this difference tended to be of greater magnitude for RDP-85 than RDP-100 (interaction, P = 0.06). In conclusion, combining forage and concentrate of different CP degradability can improve milk N efficiency in dairy cows.

Upon fermentation in the hindgut, gluconate acts as a prebiotic having shown benefits in multiple species. In previous studies, hydrogenated fat-embedded calcium gluconate (HFCG), developed to target the hindgut, improved milk and component yields in highly controlled research settings. The objective of the current study was to confirm these results in commercial dairy herds. Six farms, comprising a total of 907 lactating Holstein cows, were enrolled in a randomised cross-over design where the supplementation of HFCG (16 g/cow/d) was compared against a control. Farms were randomly assigned to one of the two possible treatment sequences and treatments were applied for ∼56 d. Milk yield and composition were measured on two milk test-days on approximately d 26 and 56 of each treatment period, and an average per animal per period was calculated. The effect of HFCG supplementation on performance was statistically analysed with two approaches: (1) using individually recorded milk yield and analysed milk composition from each test-day retrieved through the cattle improvement cooperative organization CRV (Arnhem, the Netherlands), and (2) using residual performance obtained by subtracting the observed from the predicted values estimated by the herd test-day model of CRV. Supplementing HFCG increased milk yield (3.6%; P = 0.02), protein content (1%; P = 0.01) and yield (4.6%; P = 0.01), and lactose yield (3.4%; P = 0.04); and tended to increase energy-corrected milk (3.1%; P = 0.10). The analysis of the residual performance retrieved similar trends, although with diminished statistical significancy. During the control period, milk yield, fat and protein yield, and urea content residuals were negative and significantly different from zero (P ≤ 0.05), indicating that farms underperformed relative to predictions. In contrast, during HFCG supplementation, farms performed as predicted. Overall, these results confirm the effectiveness of HFCG supplementation at improving performance at farm level.

Blood gas test evaluates hydroelectrolyte, acid-base balance, and lung function. The physiological parameters can be influenced by age and management and environmental factors, as well as the blood sample used: venous or arterial. The objective of this study was to analyze arterial and venous blood gas parameters of healthy Brahman cattle in Brazil, to determine reference values for this breed, comparing age and sex, in addition to evaluating the correlation between arterial and venous results. For the purpose of this research, 80 healthy cattle (40 males and 40 females) were grouped according to different age groups (Group I: from 5 to 30 days; Group II: from 31 days to 6 months; Group III: from 7 to 18 months; Group IV: from 19 to 36 months) and sex. The animals were examined by physical examination prior to the collection of the venous and arterial blood samples. Blood gas analyses were performed immediately after blood collections, using the I-STAT® portable device with EG7+ cartridge. There was a difference among age groups for rectal temperature (RT), respiratory rate (RR) and heart rate (HR), and age × sex interaction for RT and RR. Younger animals (Group I) had higher RT, HR and RR, regardless of sex. Females had higher RT than males, regardless of age. As for blood gas parameters, only oxygen pressure (PO₂) and arterial and venous concentrations of sodium ions (Na⁺) experienced the interaction between age × sex, while pH, carbon oxygen pressure (PCO₂), oxygen saturation (SO₂), potassium (K⁺), and calcium (iCa²⁺) concentrations of arterial and venous blood were influenced by the age of the animals. Calves in the Group I showed the main differences in blood gas parameters compared to adults (Groups III and IV). The neonates (Group I) had lower values of pH and SO₂, and higher values of PCO₂, K⁺ and iCa²⁺ of arterial and venous blood. High correlation could be observed in the values of pH, Na⁺, hematocrit and hemoglobin when measured in arterial and venous blood, therefore, one value can be obtained by the other. The other variables were very dispersed, confirming the differences pointed out in the literature between arterial and venous blood. Finally, the results of this study can be used as a reference for healthy animals of the Brahman breed.

Feed Passage Syndrome (FPS) is a prevalent condition that includes wet excreta, with undigested feed, and loss of feed efficiency, with multiple predisposing factors involved. Alternatives to antimicrobials, including phytogenics, are being studied to control this process. This study aimed to assess oregano essential oil (OEO) in broilers subjected to a natural field FPS challenge. Four broiler houses (two males; two females) presenting FPS were divided into two groups per house and assigned to a control or OEO-treated group through drinking water for five days. The FPS was characterized by >30% wet droppings, >50% with undigested feed, <5% with desquamated mucosa, >10% birds with enteritis, and 90% with undigested feed in the lower ileum, and flocks clinically positive for dysbacteriosis. After a five-day treatment, OEO-treated birds showed fewer abnormal droppings (P < 0.05), reduced the prevalence of dysbacteriosis (P = 0.0404), and a progressively recovering BW. The OEO treatment showed to influence the Gompertz growth curve parameters (growth rate, P = 0.0165; inflection point, P = 0.0359), potentially reducing the age at the target market weight in 0.8 days. In conclusion, the results indicate that the OEO treatment in drinking water for broilers naturally challenged with the Feed Passage Syndrome may improve excreta characteristics and attenuate the negative impact of the syndrome on the BW.