Nutrient Composition and Feed Hygiene of Alfalfa, Comparison of Feed Intake and Selected Metabolic Parameters in Horses Fed Alfalfa Haylage, Alfalfa Hay or Meadow Hay.

The aim of this study was to examine the nutrient composition and feed hygiene of alfalfa as well as investigate the feed intake, blood, urine and faecal parameters of horses fed alfalfa haylage (AS) compared with alfalfa hay (AH) and meadow hay (MH). A total of 11 geldings were fed ad libitum (2.1% dry matter (DM) of body weight (BW)) with alfalfa haylage, alfalfa hay and meadow hay (MH) in a Latin square design. On days 0 and 21 of the feeding period, blood samples were analysed for kidney and liver parameters. Faecal samples were analysed for pH, DM and short-chain fatty acids (SCFAs). Spontaneous urine was collected during the feeding period to analyse selected parameters. Forage was analysed in terms of feed hygiene and crude nutrients. In several feed samples of AS, AH and MH, the microbial reference ranges were exceeded for product-typical and spoilage-indicating bacteria and fungi. Crude nutrient analyses revealed a median crude protein content of 139 (138/142) g/kg DM for AS, which was similar to that in AH (127-135 g/kg DM) and substantially higher than in MH (79.1-87.7 g/kg DM). The calcium level in AS (11.3 g/kg DM) was significantly higher than that in MH (4.00-4.95 g/kg DM) but not compared with that in AH (9.80-10.4 g/kg DM). All blood parameters were within the reference ranges. Fractional excretion (FE)Ca for AS-fed horses ranged from 8.13 to 22.0%; the FECa for AH-fed horses ranged from 6.48 to 24.8%; the FECa for MH-fed horses ranged from 6.69 to 53.2%. No significant differences were found in faecal pH or SCFA content in AS-fed horses compared with AH-fed and MH-fed horses. We concluded that alfalfa haylage provides an alternative forage for equine nutrition.

Stepwise Reduction of Dietary Phosphorus in Diets for Piglets and Fattening Pigs of Different Genetic Origin Housed under Various Station Environments-A Ringtest.

The reduction of emissions of nutrients from livestock is one of the main topics in areas with intensive animal husbandry. In order to minimize the loss of nutrients into the environment, it is common practice to feed animals as close as possible to metabolic demands. For phosphorus (P), there are various studies for swine and poultry, which showed that a reduction of dietary P levels is possible, if a sufficient level of phytase is added to the diet. The supplementation of a sufficient dosage of phytase to plant-based diets leads to an increase in digestible phosphorus (dP) upon the hydrolisation of phytate (InsP6) to P and lower inositol-phosphates. However, most of these studies were conducted under standardized experimental conditions. In terms of transfer to practical conditions with varying housing, management and genetics, there are concerns that have led to speculation by farmers and veterinarians whether the reduction of dietary P could negatively affect bone health and therefore animal welfare. In order to test whether a reduction of dietary P according to the recommendations for dP of the German Society of Nutrition Physiology (GfE) affects bone mineralization and growth performance, a ringtest was conducted where piglets and fattening pigs were fed at four experimental stations with three centrally produced diets from the same batches. The diets contained three different levels of P and were designed to reflect practical diets. The P level decreased from diet one to three, respectively. Diets one and two were calculated to contain P levels, which are typically fed under practical conditions in Germany. The third diet was optimized to fulfill the requirements of dP by the GfE. The animals were fed in two phases as post-weaning piglets (8-15 kg and 15-28 kg BW) followed by a three-phase fattening regime (28-60 kg, 60-90 kg and 90-120 kg BW). Individual body weight and feed consumption (pen basis or individually, depending on the experimental station) were recorded for every feeding phase. At the end of the experiment, animals were slaughtered. At one experimental station, additional blood serum, metatarsi of the left leg and kidney tissue were sampled to analyze serum P concentration, expression of P transporters in the kidney and bone traits. In two experimental stations, femur and vertebra were sampled, and bone ash was determined. Overall, animal performance and all other traits analyzed did not differ between the treatment with the highest and the treatment with the lowest dietary P concentration. The results demonstrate that it is possible to decrease dietary P according to the recommendations for dP of the GfE, without impairing the animals' performance or mineral homeostasis and health. A reduction of total P by reducing mineral P to the levels of the present study require the supplementation of phytase to achieve sufficient concentrations of dP.

Investigation of the Formal Pathogenesis of Green Liver Discoloration in Organically Reared Female Bronze Turkeys (Melleagris gallovapo).

Green liver discoloration (GL) in fattening turkeys is suspected to be a multifactorial disease complex with a compromised immune system as the key factor. This study aimed to identify the formal pathogenesis of GL and to investigate possible nutritional influences. A total of 360 Bronze turkey hens out of 10 flocks from 5 fattening farms were necropsied for detection of GL during 2 consecutive trials on 2 examination dates each (70th to 75th and 120th to 127th day of fattening, respectively). At each examination date, hematological and clinical chemistry analyses, as well as determination of vitamin E and selenium concentrations in the liver, were carried out in 6 hens with (if applicable) and 6 hens without GL, representing a total of 130 individuals. Raw nutrient, energy, amino acid, bulk and trace element, and vitamin E and D3 concentrations were analyzed in feed samples for each of the five feeding phases during each trial. The results of the hematological analyses, clinical chemistry analyses, and determination of vitamin E and selenium liver concentrations were statistically evaluated between: (i) individuals with and without GL, and (ii) individuals from flocks with and without turkeys with GL. At both fattening stages, the occurrence of GL was characterized by an inflammatory reaction. A subacute inflammatory reaction was detected in the early fattening stage, indicating a viral cause of the disease. In the late fattening stage, acute inflammation indicated a bacterial cause of the disease. The results of the feed sample analyses of the different flocks were generally quite homogeneous. However, the nutrient and energy content of the feed likely contribute to GL pathogenesis.

The Microbiological Quality of Concentrates for Horses-A Retrospective Study on Influencing Factors and Associations with Clinical Symptoms Reported by Owners or Referring Vets.

Evidence has already been provided that feed-borne mold spores and endotoxins can trigger chronic, non-infectious respiratory disease if inhaled. Furthermore, deficiencies in feed microbiology are suspected to trigger gastrointestinal and liver disorders in horses, but the connection needs further clarification. Most of the previous studies regarding horse feed hygiene focused on forage, whereas research regarding hygienic quality of concentrates is scarce. In the present study, results of reports on hygienic quality of compound feed and cereals for horses were evaluated secondarily. Results included sensory findings, and counts of aerobic bacteria, molds and yeasts determined by cultivation and lipopolysaccharide (LPS) contents. It was found that microbial counts of compound feed exceeded VDLUFA orientation values significantly more frequently than cereals (38.4 vs. 22.6%). However, average counts of bacteria, molds and yeasts were higher in cereals than in compound feeds (p < 0.0001, respectively). Mold counts in grains were significantly higher if dry matter contents were below 86% (p = 0.0201). No relation could be established between the anamnestically reported gastrointestinal disorders or elevated liver enzyme activities and microbiological deviations. Mold counts of concentrates which were suspected to cause coughing in horses were significantly higher than mold counts of control samples (3.29 vs. 2.40 log10 cfu g−1, p = 0.0313). These results indicate that hygienic status of concentrates is relevant for horse health in the respiratory tract.

Influence of Using Perforated Plastic Flooring Beneath the Waterline on Growth Performance, Litter Quality, and Footpad Health of Broiler Chickens: A Field Study.

The aim of this study was to evaluate the effect of slatted flooring beneath waterlines in broiler barns on litter quality and, subsequently, footpad health. The hypothesis tested was that installing slatted flooring underneath waterlines helps to improve litter quality and thus reduces footpad diseases, enhancing animal welfare as a result. Five experimental runs with two groups were conducted. Each run was defined as one fattening period of 32 days and consisted of 15,000 broiler Ross 308 of both sexes. Every barn was divided into three areas (drinkers, feeders, and comfort area) for weekly sampling. No influence on growth performance was noted. The slatted flooring influenced the litter quality by preventing the litter in the experimental group (EG = 690 ± 167 g/kg DM) from becoming moisture until day 14 of the fattening period compared to the control group (CON = 636 ± 198 g/kg DM). The footpad health was also influenced by using slatted flooring, with lower camera-based footpad scores in the EG (8.80) compared to CON (22.0) at the slaughterhouse (p = 0.0258). Installing slatted flooring beneath the waterline reduced the moisture of the litter compared to the control barn in the first two weeks of age and showed a positive effect on the footpad health of the broilers at the end of fattening, which indicates an improvement in animal welfare.

Grazing Ecology of Sheep and Its Impact on Vegetation and Animal Health on Pastures Dominated by Common Ragwort (Senecio jacobaea L.)-Part 2: Animal Health.

Common ragwort (Senecio jacobaea L.) naturally occurs on species-rich grasslands. Containing pyrrolizidine alkaloids (PA), it endangers livestock health through contaminated feed. Although in vitro studies showed a detoxification capacity of PA in sheep, few field data are available on the ability of grazing sheep to cope with ragwort. During two grazing seasons on a ragwort-rich pasture, we studied: (1) To what extent do sheep voluntarily ingest ragwort and (2) What impact their grazing behavior has on animal health. Ragwort intake was monitored by counting missing plant parts and calculating their weight. From 70 sheep, seven were slaughtered at the beginning and in six-week intervals at the end of each grazing period to monitor blood parameters and liver tissue. Sheep continuously preferred ragwort. The daily intake was above the currently assumed lethal dose, varying between 0.2-4.9 kg per sheep. Clinical, hematologic, and blood biochemistry parameters mostly remained within the reference limits. Initially elevated liver copper content declined over time. The liver of all 70 animals displayed slight to moderate hepatitis, fibrosis, and proliferation of the bile ducts, but no morphological signs of liver cirrhosis. Sheep preferred and tolerated ragwort, making their grazing an option to control ragwort from both an animal health and nature conservation perspective.

The Hygienic Status of Different Forage Types for Horses-A Retrospective Study on Influencing Factors and Associations with Anamnestic Reports.

The hygienic quality of forage for horses is discussed as a potential health hazard, especially regarding respiratory diseases, colic, and hepatopathies. Therefore, the purpose of this study was to investigate the possible relations between microbiological counts, as well as endotoxin levels and disease symptoms. Data from microbiological examination reports were analyzed retrospectively, including the results of sensory examination, microbiological counts, and lipopolysaccharide contents. Sensory analysis gave an indication of deficiencies in microbiological analysis, but both methods did not give consistently equivalent results regarding the hygienic status of forage. The strongest agreements between sensory and microbiological findings were demonstrated in haylage regarding mold contamination. The influences of dry matter content on microbiological quality could be shown in haylage and hay, whereas this did not apply to straw. Deviations regarding molds and the detection of Aspergillus species occurred, especially in haylage, with values above 70% DM detected (39.6%, p=0.0021 and 47.2%, p = 0.0393). Aspergillus was detected more frequently, and average counts were higher in samples that were suspected to induce coughing in horses (p = 0.0118 and p = 0.0313, respectively). The results of the present study emphasize the importance of feed hygiene for equine respiratory health and the need for the microbiological examination of feedstuffs, since sensory analysis cannot provide an error-free prediction of microbial counts.

Grazing Ecology of Sheep and Its Impact on Vegetation and Animal Health in Pastures Dominated by Common Ragwort (Senecio jacobaea L.)-Part 1: Vegetation.

Species-rich pastures naturally contain potentially toxic plants such as common ragwort (Senecio jacobaea L.), whose pyrrolizidine alkaloids (PA) impose a risk, mainly for cattle and horses. Although in vitro studies showed detoxification capacity of PA in sheep, few field data are available to ascertain whether grazing sheep can both tolerate and reduce ragwort. In a two-year study in a ragwort-rich pasture with a stocking density of 12 sheep/hectare, we documented (1) the extent of voluntarily ingested ragwort, (2) the correlation of nutritional parameters and feeding behavior, and (3) the impact of grazing on the yield proportion and number of flowers of dominant plants. Every six weeks the vegetation underwent a botanical survey and a chemical analysis. Sheep continuously ingested ragwort between 1.2 and 4.9 kg (2020) and 1.0 and 2.2 kg (2021) per individual per day without any impact on animal health. The more biomass ragwort produced, the more it contained sugar (r = 0.59-0.74), and the more sheep ingested it (r = 0.94-0.95). Other herbs increased their yield proportion from 23.3 to 36.5%, while that of ragwort decreased from 26.3 to 18.8% (2020/2021), doubling its flowers. Sheep preferred and tolerated ragwort, making their grazing an option to control ragwort from both an animal health and a nature conservation perspective.

Influence of Feeding Compound Feed Rich in Fibre during Parturition and Lactation on Health and Performance of Sows.

The aim of this study was to investigate the influence of ad libitum access to compound feeds rich in fibre (ante partum (a.p.) and peri partum) on the DM intake, body mass development and performance of sows as well as excretion of Clostridium (C.) perfringens via sows' faeces. From day 109 (d-7) of gestation, 25 of 48 sows (23 considered as control) received access to one of two different high-fibre pellets from d-7 until the second day post partum (p.p.) (d2) (fibre groups (FG) 1 and 2) in additional to a lactation diet. The additional DM intake of the high-fibre pellets a.p. was 2.13 ± 1.15 kg in FG 1 and 3.14 ± 0.68 kg in FG 2. This led to higher DM intake in the first lactation week and significantly lower losses of weight and back fat thickness during lactation. The bacterial counts of C. perfringens in sows' faeces directly p.p. were 10 times lower in FG 1 and 100 times lower in FG 2 compared to the controls. High amounts of fibre led to higher DM intake throughout lactation, which had beneficial effects on sows' body conditions. It seems that high fibre intake influenced the excretion of C. perfringens at parturition, which could improve the health of newborns.

Feasibility Study on the Use of Infrared Thermography to Classify Fattening Pigs into Feeding Groups According Their Body Composition.

Fattening pig husbandry and associated negative environmental impacts due to nitrogen inputs by ammonia emissions are current issues of social discussion. New resource-efficient feeding systems offer great potential to reduce excess nutrient inputs into the environment. Using ultrasound measurements, fattening pigs can be divided into performance groups based on their backfat/muscle ratio to feed them according to their nutritional needs. Ultrasound measurements are not suitable for practical use, so alternatives have to be found. As a non-invasive, contactless method, infrared thermography offers many advantages. This study investigated whether infrared thermography can be used to differentiate between "fat" and "lean" animals. Two evaluation methods with different measurement spot sizes were compared. During a fattening period, 980 pigs were examined three times with an infrared camera. Both methods showed significant differences. Body surface temperature was influenced by factors like measurement spot size and soiling of the animals. Body surface temperature decreased (-5.5 °C), while backfat thickness increased (+0.7 cm) in the course of the fattening period. Significant correlations (R > |0.5|; p < 0.001) between both parameters were found. Differentiation between "fat" and "lean" animals, based on temperature data, was not possible. Nevertheless, the application of thermography should be investigated further with the aim of resource-efficient feeding. The results of this feasibility study can serve as a basis for this.

Validation of a New Resource-Efficient Feeding System for Fattening Pigs Using Increased Crude Fiber Concentrations in Diets: Feed Intake and Ammonia Emissions.

The feeding of fattening pigs and its associated ammonia emissions are current core problems in social debate that affects climate change and sustainability. Feeding methods offer great potential to increase animal welfare and sustainability, and negative impacts on the environment can be reduced. Fattening pigs differ in their performance potential and in their nutrient requirements. A high feed intake capacity can lead to luxury consumption. Diets rich in crude fiber should prevent excess feed intake and cause better nitrogen fixation by microorganisms in the animals' large intestines. In a pig fattening farm, it was investigated whether and how diets rich in crude fiber can influence feed intake and ammonia emissions. The animals were divided into feeding groups according to their presumed performance potential by ultrasound examinations. Therein, body compositions were evaluated, and feed intake capacity and body weight were automatically recorded. The aim of the study was to enable adapted feeding of the animals by regarding their individual differences in body composition and performance potential. Roughage-based diets had significant influence on feed intake and did not increase ammonia emissions. Based on the results of this study a performance-based control of the feed intake should be made possible.