Animal - Open Space最新文献

Due to the evolution of welfare laws and the search for novel methods to study pig microbiota, the development of precise and non-invasive sampling methods is key to studying the microbial communities that inhabit the guts of pigs. Administering swallowable devices to pigs is always a challenge due to factors such as anatomy, the requirement for specific materials, and the need to restrain the animals. In this study, we describe a step-by-step protocol on how to administer Capsule for Sampling (CapSa), a biocompatible non-invasive device to study pig’s microbiota without harming the animals. The validation of the protocol was done through two different studies. In Study 1, 92 Swiss Large White pigs (BW: 6.45–71.3 kg) were administered two capsules each and monitored for the following 3 days for capsule retrieval. On day 3, all pigs were euthanised to locate the missing capsules directly from their gastrointestinal tracts. In Study 2, 16 Swiss Large White pigs were selected at weaning and administered CapSas at five different timepoints (T1: 52 ± 3; T2: 70 ± 3; T3: 83 ± 3; T4: 110 ± 3; T5: 126 ± 3 days of age). To retrieve the capsules in the faeces, pigs were monitored 3 days postadministration. At T5, the pigs were slaughtered, and CapSas that were not found in the faeces, termed as missing CapSas, were retrieved from their gastrointestinal tracts. The protocol entails acclimation of the animals, housing modifications, administration of a prokinetic agent (prucalopride) to facilitate gastric emptying, and oesophageal intubations to overcome challenges related to administration, gastric blockage, and retrieval of the capsules. In Study 1, 46.74% of the administered CapSas were found in the faeces within 72 h postadministration, with 47.67% retrieved within the first 24 h, and 28.26% were located in the stomach. The CapSa retrieval was lowest in light pigs (<12 kg). In Study 2, 75.6% of CapSas were recovered in the faeces within 72 h postadministration, with 51.23% retrieved within the first 24 h. The CapSa retrieval rates varied depending on the administration time point being lowest at T1 and T3 and highest at T2 with intermediate values at T4 and T5. In both studies, the pH levels were affected by transit time (P < 0.01), resulting in a more acidic content when capsules were expelled after 36–40 h. To the contrary, the volume of the CapSa content was never affected by transit time (P < 0.05). In both studies, postmortem observations showed no health-related issues except one pig from Study 2 excluded due to respiratory distress. The present study describes a valid procedure for administering CapSa or any other swallowable devices in pigs. Moreover, this procedure is applicable to singular and repetitive administrations over the lifespan of pigs.

Measuring individual intake in animals raised in groups is a paramount aspect for different fields of animal production, both with a direct implication and relevance on the production itself, i.e. within breeding programmes for the improvement of feed efficiency; or for research in different disciplines such as animal behaviour or animal nutrition. The rabbit is one of the few species for which there is no device for measuring this trait. Thus, we aimed to design and manufacture a feeding device (eFeederRab) allowing such recording. In the present study, we describe the methods behind the tool we have developed, accompanying the description with a set of descriptive statistics showing the performance of the tool. We use records from 430 animals belonging to lines selected for different feed efficiency criteria − some of them raised using the eFeederRab -, as well as from their control unselected population. Measurements were taken from 35-38 to 56–59 days of age. The lines selected for reducing residual feed intake clearly show a lower daily feed intake, 8–15% when the lines were compared using eFeederRab, and 7–10% when the lines were compared using conventional feeders. These are clear indications about the validity of the device for recording data to be used in selection to improve feed efficiency, i.e., biologically meaningful records. In spite of the biological relevance of the recorded data, when comparing performances of the lines raised using eFeederRab or conventional feeders, it was evident that feed intake was reduced by around 12–20% when using the electronic feeder, with the subsequence growth penalization. Note however that this penalty is proportional to the intake; therefore, the feed conversion ratio remains fairly similar (2.99–3.13) between the two types of feeders also reflecting the expected tendency according to the different selection criteria across lines. We hypothesise that this reduction in the intake is a consequence of the less comfortable eating posture that eFeederRab imposes: each animal must eat alone and inside a tunnel for leading the animals one by one towards the feeder to grant their proper identification by radio frequency. We can conclude that although the eFeederRab is a device with different animal feeding conditions than those on conventional feeder, the records, despite being noisy, can be successfully used to improve the genetic selection of feed efficiency in rabbits.

Digestible energy (DE) accounts for the major fraction of the energy content of hay fed to equines, but DE measurements are difficult to carry out, and researchers have developed models for predicting the DE content of hays for horses from their chemical composition. Digestible energy varies depending on botanical family, species, and agronomic and climatic conditions. A database of 61 hays harvested in a temperate zone (32 natural grassland hays, 16 grass hays and 13 lucerne hays) was set up from studies carried out at the French National Institute of Agricultural Research (INRAe) or extracted from the literature using a similar methodological corpus, to test the relevance of crude fibre (CF), NDF, ADF, total free reducing sugars (TFRS), CP as potential criteria for the prediction of organic matter digestibility (OMD), energy digestibility (ED) and digestible energy (DE). Models were developed for natural grassland hay, grass hay and lucerne hay. The adjusted cross-validation R² values (R²CV) of the models obtained using CF, ADF or NDF as single variables or in combination with CP for the prediction of OMD, ED and DE of natural grassland hay ranged from 0.84 to 0.86, from 0.83 to 0.86 and from 0.82 to 0.84, respectively. For grass hay, the R²CV were lower and ranged from 0.65 to 0.71, from 0.63 to 0.71 and from 0.62 to 0.68, for the prediction of OMD, ED and DE, respectively. Finally, for lucerne hay, the R²CV ranged from 0.65 to 0.72, from 0.34 to 0.74 and from 0.25 to 0.67, for the prediction of OMD, ED and DE, respectively. The R²CV of the prediction models of ED and DE were more heterogeneous for lucerne hay than for grassland and grass hay. The TFRS content of hay was never a significant predictive variable of OMD, ED or DE, either as single variable or combined with any cell wall content criterion. The models obtained in the present study improved those proposed by INRA to date.

This study compared two collection methods (CMs) to obtain ileal content from broiler chickens to determine apparent ileal amino acid digestibility coefficients (AIAAD). CM1 consisted of collecting the digesta by gently squeezing the ileum, while in CM2, the ileal digesta was flushed with distilled water. A total of 130 one-day-old male chicks were randomly distributed among 10 cages, using five replicate cages per CM. Birds were fed ad libitum with a standard starter diet from 0 to 18 d of age. At 18d, the diet switched to a corn-based semi-purified diet with 0.5% titanium dioxide (TiO2) as the indigestible marker. At 21d, birds were euthanized, and ileal digesta was collected using one of the two CMs. Bird performance was monitored; feed and lyophilized ileum content samples were analyzed to determine amino acids (AAs) and Ti content to determine AIAAD. A two-sided T-test and an F-test two-sided were performed to determine differences among the CMs’ means and variances, respectively. All significant differences were considered at a P-value < 0.05. Bird performance was similar for both groups throughout the experiment (P > 0.05). No significant differences between CMs were observed in the AIAAD coefficients for any of the amino acids analyzed (P < 0.05). The variances were significantly different for 6 AA (Iso, Lys, Thr, Ala, Asp, Glu; P < 0.05). In addition, four AAs approach significance (Leu, Met, Val, Pro; P < 0.1). The numeric values of the AAs variances were consistently higher when the sample was obtained using CM1. Squeezing may increase variability by enhancing endogenous losses like sloughed cells and mucin, underestimating digestibility in some samples. Using CM2 (flushing with distilled water) would provide more consistent and uniform results. This approach not only diminishes the likelihood of errors but also contributes to the standardization of methodologies applied in digestibility trials within the poultry research field.

The infection of the endophytic fungus (Epichloë festucae var. lolii) within perennial ryegrass (Lolium perenne) pastures can produce toxic alkaloids, including lolitrem B and ergovaline which can negatively impact animal welfare and behaviour through causing ryegrass staggers as well as poor growth and increased sensitivity to heat stress. Wearable 3-axis acceleration sensors can provide an alternative to automatically monitor individual grazing livestock who need essential treatment to minimise the impact of grazing pastures infected with an endophyte. The objective of this study was to categorise changes in ruminating, eating and other behavioural activities of grazing lambs exposed to endophyte-infected perennial ryegrass via commercial accelerometer sensors. Lambs were fitted with the ear-mounted accelerometer sensors (CowManager SensOors, Agis, Harmelen, the Netherlands) and allocated randomly within live-weight strata to graze either endophyte-free (Control) or wild−type endophyte-infected (Endophyte) perennial ryegrass pasture. Live weight change, behaviour and incidence of staggers were monitored over a 2-month grazing period. Moderately severe staggers (score 4/5) occurred in 40% of lambs in the Endophyte treatment with a mean staggers score of 2.33 ± 0.41 across the group. Compared with control lambs, endophyte-infected lambs compensated for reduced eating (−36.0 min/day) and inactive (−43.7 min/day) duration in favour of increased ruminating (+40.2 min/day) and active (+29.9 min/day) duration. The sensors also identified diurnal adaptations in behaviour of lambs which were affected by endophyte staggers, presenting significant effects of endophyte challenge by hour interaction on the diurnal eating duration (P < 0.001), diurnal ruminating duration (P < 0.001), diurnal inactive duration (P < 0.001), diurnal active duration (P < 0.001) and diurnal highly active duration (P < 0.001). In conclusion, these sensors were able to detect subtle changes in the behaviour of grazing sheep that can be used to detect subclinical symptoms of ryegrass staggers when consuming ryegrass staggers.

This study investigated the impact of the age at which heifers conceive for the first time on the growth and reproductive development of their female offspring. A total of seven heifers pregnant at 15 months of age (15M), nine heifers pregnant at 27 months of age (27M) and seven multiparous pregnant cows (Adult) were used in the present trial. All dams were pregnant by AI from a single sire and managed in a single group during gestation, lactation and rearing stages. After weaning heifer calves were stocked on natural pastures. Progeny of heifers that gestated for the first time at different ages did not present differences in growth; however, progeny of 15 and 27M dams had reduced BW, longissimus muscle area and 12th fat thickness compared to progeny of adult dams (P < 0.05). Diameter of the largest follicle was greater in progeny born to Adult compared to progeny born to 15 and 27M (P = 0.04). Reproductive tract score (RTS) in heifers born to Adult at 399 days of age was greater compared to heifers born to 27M, and this category presented greater development than heifers born to 15M (P = 0.02). At 435 days of age, the heifers born to Adult had a greater percentage defined as pubertal compared to the progeny of 15 and 27M (P = 0.04). At 495 days of age, the weight of uterus, ovaries and corpora lutea were not affected by the age of dams at calving (P > 0.25). These data indicated that the age at which heifers received their first service affects female offspring growth RTS at early ages, but it does not have any impact in organ development after diet with a high energy level.

Considering the potential environmental impact of livestock production and the significance of accurate estimation methods, it is crucial to assess the differences between various methodologies. The study compared the gross energy intake (GEI) and enteric methane (CH₄) emission factors (EF = kg CH₄/head/year) of cattle based on three methodologies: Intergovernmental Panel on Climate Change (IPCC) Tier 1, IPCC Tier 2 and a modified Tier 2 methodology based on Commonwealth Scientific and Industrial Research Organization (‘CSIRO’) Tier 2. Data were collected from smallholder mixed crop-livestock systems in the upper highland sub-humid to semi-humid (AEZ-1) and lower highland sub-humid to semi-humid (AEZ-2) zones of North Shewa, Ethiopia, corresponding to the beginning and end of spring, summer, and winter. The results revealed that the IPCC Tier 2 methodology estimated a 39% higher GEI (104 vs 74 MJ/ head^/day) and a 51% higher implied EF (50 vs 33 kg CH₄ /head/year) compared to the ‘CSIRO’ Tier 2 methodology. When compared to the IPCC Tier 1 default values, both the IPCC and ‘CSIRO’ Tier 2 EF estimates were 20–37% and 37–59% lower, respectively. Furthermore, all cattle categories exhibited variations in implied daily CH₄ production across seasons. As all the GEI were estimated, it is not possible to determine which methodology is more accurate. Therefore, future research should compare predicted intakes and emissions with actual experimental data to ascertain the accuracy of the models.

The objective of the current trial was to evaluate the effect of feeding four different forage species on milk yield and composition, including protein and fatty acid profiles, in dairy goats. Two grasses (Timothy; mown at early heading, and Italian ryegrass; mown at 25 cm height) and two legumes (Alfalfa and White clover; both mown at 10% bloom) were harvested and conserved as silage. Twelve dairy goats of three different breeds (4 Alpine, 4 Toggenburg, and 4 Saanen) in late lactation were used in a replicated 4 × 4 Latin square design. Goats were offered ad libitum access to the tested forages supplemented with 180 g/d of concentrates based on rolled barley and heat-treated soybean meal. DM intake was lower with timothy, intermediate with ryegrass and white clover, and greater with alfalfa. Milk yield was lower with timothy as compared with the other three silages. Milk fat yield was similar among treatments. Milk CP yield was lower with timothy as compared with the other three silages. Milk N efficiency (N secreted/N intake) was greater with timothy, intermediate with ryegrass, and lower with the two legume silages. The proportion of true protein as a percentage of CP was lower in milk from goats fed legume as compared with grass silages. Proportions of casein and whey protein expressed as percentages of true protein were greater with timothy, intermediate with ryegrass and white clover, and lower with alfalfa. Among grass silages, intake and milk secretion of cis-9, cis-12 cis-15 18:3 was greater with ryegrass than with timothy. As a result, the transfer efficiency from dietary intake to secretion in milk was not different between these two treatments. Fewer differences were observed regarding legume forages, as cis-9, cis-12, cis-15 18:3 intake and milk secretion were similar with alfalfa and white clover. However, the transfer of cis-9, cis-12, cis-15 18:3 from diet to milk was highest when feeding alfalfa. In conclusion, forage species fed to dairy goats influence milk composition in terms of fatty acids and protein fractions, which can potentially impact the nutritive value and technological properties of milk.