Evaluation of Foot and Claw Lesions and Claw Horn Growth in Piglets from Birth to End of Nursery.

The objective of this study is to evaluate foot lesions and claw horn growth of piglets from the day of birth until the end of the suckling period and describe the prevalence and extent in three different genetic lines. Therefore, bruising, dorsal horn lesions, claw horn growth, and weight gain were evaluated five times during growth, starting with the day of birth (day 0 of life) and ending with the end of nursery (day 68 ± 2 of life). Totally, 74 piglets of three genetic lines (German Landrace × Large White; Piétrain × Piétrain-Duroc; pure German Landrace) were examined. Bruising and dorsal horn lesions reached maximum levels at day 7 (±1) of life (with up to 91% of piglets having bruising marks and up to 94.1% of piglets having dorsal horn lesions). Differences among genetic lines were detected, with German Landrace × Large White crossbreds showing the highest percentage of bruising, but Piétrain × Piétrain-Duroc crossbreds showed the highest score for dorsal horn lesions at day 0. Until weaning (day 28 ± 1), front feet were more affected by bruising than hind feet (70.3% of the front feet and 64% of the hind feet showed bruising), but at the end of nursery (day 68 ± 2), hind feet showed a higher percentage of affected feet than front feet (65.5% vs. 41.3%). Several factors affect bruising scores in piglets, including body weight, age at examination, litter size, sex, parity, breed, and claw horn length. Additionally, significant differences for claw horn length were detected among the genetic lines from birth to end of nursery.

Feed Efficiency and Physiological Parameters of Holstein and Crossbred Holstein × Simmental Cows.

This study aimed to compare the feed efficiency (FE) and physiological parameters of Holstein and crossbred Holstein × Simmental cows in a confinement system during winter and summer. The study was conducted in a dairy farm in southern Brazil by including a total of 48 multiparous cows. The cows were studied for 21 days in two periods, summer and winter, and their daily dry matter intake (DMI), milk yield (MY), rectal temperature (RT), respiratory rate (RR), body weight, and body condition score were recorded. An analysis of variance was conducted using the SAS statistical package. The results showed that crossbred Holstein × Simmental cows have a similar FE as Holstein cows in a high-production system (1.83 × 1.81 kg DMI/kg MY, respectively), and they can achieve the same production levels as purebred Holstein cows (43.8 vs. 44.5 milk/cow/day). Our findings indicated a difference for the period as both genetic groups achieved higher FE in winter than in summer (1.98 vs. 1.67 DMI/kg MY, respectively). In addition, we found evidence that crossbred cows are better at dissipating body heat during heat-stress situations, as they have higher RR in summer compared to purebred cows, while Holstein cows have higher RT in summer afternoons than crossbred cows. Therefore, using crossbred Holstein × Simmental cows is an alternative for high-production systems.

Magnetic Resonance Imaging Used to Define the Optimum Needle Length in Pigs of Different Ages.

Intramuscular injections result in tissue destruction and alteration. Therefore, it is necessary to evaluate the optimum injection point for intramuscular injections. As animals­especially pigs­vary in size and explicit information about injection depth is not available. To determine the predicted optimum injection depth, magnetic resonance imaging was used in pigs of different ages and weight groups. In total, 730 magnetic resonance images of 136 pigs were used to calculate the optimum injection depth for intramuscular injections. Four age groups were evaluated: <29 days of age, 29−70 days of age, 71−117 days of age and >170 days of age. For fattening pigs (71−117 days of age), the present study recommends a needle length of 20 mm (range: 40−58 mm). For younger pigs (<70 days of age), a needle length of 12 to 14 mm (range: 10−18 mm), and for older pigs (>170 days of age), a needle length of 30 mm (range: 25−37 mm) is recommended. However, more data are needed. Therefore, further studies are necessary, especially in the youngest (suckling pigs) and oldest (sows) age groups, as these are the groups mainly injected/vaccinated. Additionally, age and weight should be examined in more detail compared to fat distribution in the neck, genetics and the sex of the animal.

Identification and Functional Annotation of Genes Related to Bone Stability in Laying Hens Using Random Forests.

Skeletal disorders, including fractures and osteoporosis, in laying hens cause major welfare and economic problems. Although genetics have been shown to play a key role in bone integrity, little is yet known about the underlying genetic architecture of the traits. This study aimed to identify genes associated with bone breaking strength and bone mineral density of the tibiotarsus and the humerus in laying hens. Potentially informative single nucleotide polymorphisms (SNP) were identified using Random Forests classification. We then searched for genes known to be related to bone stability in close proximity to the SNPs and identified 16 potential candidates. Some of them had human orthologues. Based on our findings, we can support the assumption that multiple genes determine bone strength, with each of them having a rather small effect, as illustrated by our SNP effect estimates. Furthermore, the enrichment analysis showed that some of these candidates are involved in metabolic pathways critical for bone integrity. In conclusion, the identified candidates represent genes that may play a role in the bone integrity of chickens. Although further studies are needed to determine causality, the genes reported here are promising in terms of alleviating bone disorders in laying hens.

Keel Bone Damage in Laying Hens-Its Relation to Bone Mineral Density, Body Growth Rate and Laying Performance.

Keel bone damage is an important animal welfare problem in laying hens. Two generations of four layer lines, differing in phylogenetic background and performance level and kept in single cages or floor pens were weighed and scored for keel bone deformities (KBD) during the laying period. KBD, keel bone fractures (KBF) and the bone mineral density (BMD) of the keels were assessed post mortem. For BMD, relationships to laying performance and body growth were estimated. Caged hens showed more deformities, but fewer fractures and a lower BMD of the keel bone than floor-housed hens. White-egg layers had a lower BMD (0.140-0.165 g/cm2) and more KBD than brown-egg layers (0.179-0.184 g/cm2). KBF occurred more often in the high-performing lines than the moderate-performing ones. However, in the high-performing lines, BMD was positively related to total egg number from 18 to 29 weeks of age. The adult body weight derived from fitted growth curves (Gompertz function) had a significant effect (p < 0.001) on keels' BMD. The study contributes to the understanding of predisposing factors for keel bone damage in laying hens. It showed that the growth rate has a rather subordinate effect on keels' BMD, while the BMD itself greatly affects KBD.

Detection of Local Tissue Reactions after Anti-GnRF Injection in Male Pigs Assessed Using Magnetic Resonance Imaging.

This study aimed at evaluating the local tissue reaction of an anti-GnRF product, which is used for the so called "immunocastration" in male pigs. A total of 34 pigs were injected two times (including a booster injection) with an anti-GnRF product. Injection was performed using the prescribed safety vaccinator. Injection sites were evaluated three times post injection using magnetic resonance imaging. Two examinations were performed after the first injection and one after the booster. The local tissue reaction was evaluated three-dimensionally by semi-automatic analyses, by linear measurements of injection depth and length, and by scoring the kind of tissue affected. Results showed a long-lasting reaction in affected muscle tissue. Therefore, needle length should be discussed, and an evaluation of the injection site after slaughter should be performed include behavioural scorings post injection to evaluate the impact on animal well-being and carcass quality.

Correction: Jansen, S., et al. Relationship between Bone Stability and Egg Production in Genetically Divergent Chicken Layer Lines. Animals 2020, 10, 850.

The authors wish to make the following corrections to this paper [...].

Egg Production and Bone Stability of Local Chicken Breeds and Their Crosses Fed with Faba Beans.

Poultry production is raising concerns within the public regarding the practice of culling day-old chicks and the importation of soy from overseas for feedstuff. Therefore, an alternative approach to poultry production was tested. In two consecutive experiments, two traditional chicken breeds, Vorwerkhuhn and Bresse Gauloise, and White Rock as a commercial layer genotype as well as crossbreds thereof were fed diets containing either 20% vicin-rich or vicin-poor faba beans, though addressing both subjects of debate. Hen performance traits and bone stability were recorded. All parameters were considerably influenced by the genotype with White Rock showing the significantly highest (p < 0.05) laying performance (99.4% peak production) and mean egg weights (56.6 g) of the purebreds, but the lowest bone breaking strength (tibiotarsus 197.2 N, humerus 230.2 N). Regarding crossbreds, the Bresse Gauloise × White Rock cross performed best (peak production 98.1%, mean egg weight 58.0 g). However, only limited dietary effects were found as only the feeding of 20% vicin-rich faba beans led to a significant reduction of egg weights of at most 1.1 g (p < 0.05) and to a significant reduction of the shell stability in the crossbred genotypes. In terms of dual-purpose usage, crossing of Bresse Gauloise with White Rock seems to be the most promising variant studied here.

Relationship between Bone Stability and Egg Production in Genetically Divergent Chicken Layer Lines.

Impaired animal welfare due to skeletal disorders is likely one of the greatest issues currently facing the egg production industry. Reduced bone stability in laying hens is frequently attributed to long-term selection for increased egg production. The present study sought to analyse the relationship between bone stability traits and egg production. The study comprised four purebred layer lines, differing in their phylogenetic origin and performance level, providing extended insight into the phenotypic variability in bone characteristics in laying hens. Data collection included basic production parameters, bone morphometry, bone mineral density (BMD) and bone breaking strength (BBS) of the tibiotarsus and humerus. Using a multifactorial model and regression analyses, BMD proved to be of outstanding importance for bone stability. Only for the tibiotarsus were morphometric parameters and the bone weight associated with BBS. Within the chicken lines, no effect of total eggshell production on BBS or BMD could be detected, suggesting that a high egg yield itself is not necessarily a risk for poor bone health. Considering the complexity of osteoporosis, the estimated genetic parameters confirmed the importance of genetics in addressing the challenge of improving bone strength in layers.

"Sex" and body region effects on bone mineralization in male pigs.

Lameness in pigs is one of the major reasons for culling and early losses in pigs. This can be linked to osteoporosis due to pathologic alterations in bone mineral density (BMD) or bone mineral content (BMC) and may also be linked to the sex. Dealing with the ban on piglet castration without anaesthesia in Germany 2021, we have three male "sex" types: entire boars (EB), immunocastrated boars (IB), and surgically castrated boars (SB). The hypothesis of the present study is that BMC or BMD varies between different male sex types. If sex has an effect on bone mineralization (BMC or BMD) and if this affects leg health, it could result in more lameness and problems during fattening in the negatively affected sex type. The present study evaluated bone mineralization (in terms of BMD and BMC) and body composition traits using dual-energy X-ray absorptiometry (DXA) three times during growth at 30, 50, and 90 kg live body weight. Nine body regions were analysed for bone mineral traits and compared for different male sex types and the fattening season. Significant differences were found regarding BMD (and BMC) among EB, IB, and SB for whole-body BMD (BMC). Additionally significant differences were found in the front and lower hind limbs, where SB showed a significantly higher BMD compared to EB, with IB in between. Additionally regional differences were detected among the groups. Further studies are needed to evaluate the effect of these differences in bone mineralization on leg health.

Reproductive and productive performance, udder health, and conformation traits of purebred Holstein, F1, and R1 crossbred Holstein × Simmental cows.

The objective of this study was to compare the reproductive performance, milk yield and composition, and udder health and conformation traits of Holstein (Ho), F1, and R1 crossbred Ho × Simmental (Sim) cows. Three commercial dairy farms in south Brazil were used as the research units. All farms held Ho, F1, and R1 crossbred Ho × Sim (¾ Ho × » Sim and ¾ Sim × » Ho) cows. The collection of milk samples and evaluation of udder conformation traits occurred during four visits to each farm. In addition to the actively collected data, retrospective reproduction records of the farms served as the basis for the statistical analysis using analysis of variance models using SAS. The F1 crossbred Ho × Sim cows and ¾ Sim (first rotational crossbreeding generation = R1 using Sim semen) cows had a shorter calving interval and calving to first service interval compared to the Ho cows (P < 0.0001). Milk yield did not differ among the genetic groups except for R1 (¾ Sim) that produced approximately 10% less milk than the other groups (P = 0.0245). Fat plus protein yield and somatic cell score did not differ among the genetic groups. Ho cows had shallower udders (P < 0.0001) and a higher udder clearance (P < 0.0001) than the other groups. F1 and R1 crossbred Ho × Sim cows had shorter reproduction intervals than purebred Ho cows. Although udder conformation traits lacked high-quality scores in crossbred cows, somatic cell scores reached the same level as in purebred Ho cows.

Vaccine safety testing using magnetic resonance imaging in suckling pigs.

Safety testing is one major part of the licensing procedure for veterinary vaccines and demands a large number of animals. Magnetic resonance imaging (MRI) was tested as an alternative, which may lead to a reduction in numbers of animals required for safety testing, and, correspondingly to a detailed description of the three-dimensional extent of the local tissue reaction repetitively in live pigs. In previous pig studies the following questions arose:To answer these questions the following study was performed by comparing two vaccine groups of suckling piglets (8 animals per group; A and B) with two control groups (4 animals per group; C and D). One control group was injected with a saline solution (C) and the other was only tattoo marked (D). The animals were examined using MRI at days 1, 8, 15, 22, 29, 36, and 43 post vaccination, ending with a final pathomorphologic examination. Pathomorphologic examination confirmed MRI findings. Saline solution does not result in a local tissue reaction as detected after injecting vaccines. Tattoo marking causes no local tissue reaction, neither in MRI nor in pathomorphologic examination. Therefore, MRI can be used as an alternative method for safety testing of vaccines in pigs of different age categories offering repetitive measurements of local tissue reactions. Involved cells might be examined only in a final pathomorphologic examination at the end of the trial on a reduced number of animals.

Magnetic resonance imaging to detect local tissue reactions after vaccination in sheep in vivo.

OBJECTIVES: Vaccination is one of the most effective methods to keep up the health status in humans and in livestock. Therefore, farm animals are vaccinated several times during their lifetime. Although vaccines are being checked regarding their local reactogenicity, side effects occur frequently-especially in the case of the application of adjuvanted products. Many reports exist about local reactions in sheep. The present study aimed at testing MRI as a method to document injection site reactions three-dimensionally. DESIGN: Two groups of Merino lambs (n=16 each) were vaccinated subcutaneously into the left neck side. Two different, licensed inactivated vaccines were used. Both groups of lambs were anaesthetised and scanned using MRI at days 1, 3, 8, 15, 22 and 29 after vaccination. SETTING: The study was performed on a commercial-like farm. PARTICIPANTS: Thirty-two Merino lambs entered the experiment, 16 male and 16 female ones (one animal died at day 22 after vaccination). At first examination day they were approximately three months old. PRIMARY AND SECONDARY OUTCOME MEASURES: Volume differences were measured between vaccination and control neck side to evaluate the time pattern of local tissue reactions. RESULTS: Local tissue reactions were visible on the skin surface and also appeared in deeper tissue layers on MRI. These deeper reactions would not have been found without MRI or, alternatively, without sacrificing the animals. Some of these extensive local reactions lasted for more than 29 days. CONCLUSIONS: The in vivo MRI results proved suitable to record local tissue reactions in terms of three-dimensional extent over a longer period of time in large farm animals without the need to sacrifice test animals. A three-dimensional MRI examination of the injection site during regulatory licensing studies offers an objective evaluation that could be used in a benefit-risk assessment of veterinary vaccines. TRIAL REGISTRATION NUMBER: District Government of Upper Bavaria:55.2-1-54-2532-2-13.

Assessment of local reaction to vaccines in live piglets with magnetic resonance imaging compared to histopathology.

The safety of veterinary vaccines is assessed in clinical trials in Europe. The assessment of the local tissue reaction to vaccination by magnetic resonance imaging (MRI) could reduce the number of animals needed because repeated examinations can be performed in the same animal over time. The present study compared the evaluation of local tissue reactions to vaccination using MRI in live pigs with histopathology of porcine tissue, the current gold standard in regulatory safety testing. Eight piglets each were administered one of two commercial vaccines into marked injection sites. All animals were sedated and scanned repeatedly by MRI using a contrast agent up to day 29 after vaccination. On day 29, the animals were euthanized and underwent a pathological examination. The MRI results were compared with the pathomorphological findings at the injection site by regression analysis. The MR images and the pathological examinations yielded matching results concerning the sizes of the affected tissue volumes or areas. The use of MRI for regulatory safety testing can reduce the number of animals needed to 8 per examination group. The volume of a local reaction and its progression over time can be evaluated and documented. If persistent lesions develop a final pathomorphological examination is needed to identify the kind and local distribution of the reaction.