Effect of replacing whole wheat with broken rye as a sustainable grain in diets of fattening turkeys on growth performance, litter quality, and foot pad health.

Introduction: Rye is one of the most important cereal crops in Central Europe, thus attempts have been made to include it in the diets of birds to reduce production costs, since the cost of feed accounts for as much as 50 %-70 % thereof. Nevertheless, the use of rye has been limited to date, particularly in turkeys. This study aimed to test the effects of rye inclusion up to 10 % on growth, excreta, and/or litter dry matter, and foot pad health. Methods: Four trials were performed with a total of 4,322, 4,307, 4,256, and 4,280 female turkeys (BUT BIG 6, Aviagen) for trials 1, 2, 3, and 4, respectively. All birds were fed commercial starter diets for the dietary phases 1 and 2 (up to d 35 of life). Thereafter, at the start of the study, the control group received commercial supplementary feed with 5 % or 10 % wheat until the end of the fattening period. The experimental group was offered supplementary feed to which instead of wheat increasing levels of rye were added stepwise from 5 % to 10 %. Results: Using supplementary feed with rye showed no significant differences in the final body weight between the control and experimental groups (10.9 vs. 10.8 kg). The dry matter content of fresh excreta for turkeys during the experimental period did not show significant differences between both groups, except at weeks 10 and 14 of life. The feed type (either control diet or experimental diet) did not significantly affect litter dry matter content between the groups throughout the experimental period. No significant differences were noted in food pad dermatitis scoring between both groups throughout the experimental period, except at weeks 11 and 16 of life. Overall, this study showed that including proportions of rye up to 10% could replace conventional ingredients and may increase sustainability in poultry production regardless of the addition of supplementary feed.

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.

Effects of Early Nutrition of Hatched Chicks on Welfare and Growth Performance: A Pilot Study.

This study aimed to investigate the possibility of rearing newly hatched chicks with immediate access to feed and water in the same hatching unit one week prior to transferring them to the conventional broiler house with special regards to foot pad health and growth performance. Two trials were performed with a total of 6900/6850 (trials 1/2) broiler chickens (ROSS 308). A total of 3318/3391 chicks (trials 1/2) were transported from the hatchery (duration of about 3 h) and reared in a conventional broiler house (control group: delayed nutrition on-hatchery hatched). The control group did not receive any form of nutrition until they were taken to conventional broiler housing. Additionally, a total of 3582/3459 (trials 1/2) embryonated eggs (d 18) were obtained from the same parent flock of the same commercial hatchery and taken to the farm facility. After on-farm hatch, the chicks had immediate access to water and feed (experimental group: early nutrition on-farm hatched). After d 6/7 of life, the on-farm hatched chicks (trials 1/2) were transferred to the broiler house on the same facility. The delayed nutrition on-hatchery hatched groups displayed a significantly lower dry matter content in the litter compared to the early nutrition on-farm hatched groups (two-factorial analysis) at d 6/7 and d 14 of life. However, thereafter, no significant differences were noted. Based upon two-factorial analysis, the early nutrition on-farm hatched groups revealed lower foot pad lesions from d 14 of life onwards and showed a higher body weight (BW) throughout the rearing period compared to the delayed nutrition on-hatchery hatched groups (p < 0.05). Overall, early nutrition on-farm hatched chickens is of critical importance together with using new litter at d 7 to maintain healthy foot pads as well as to enhance nutrient utilization and optimize the growth performance.

Impact of Nematode Infections on Non-specific and Vaccine-Induced Humoral Immunity in Dual-Purpose or Layer-Type Chicken Genotypes.

Nematode infections may induce immune-modulatory effects and influence host-immune responses to other pathogens. The aim of the study was to investigate whether a mixed nematode-infection influences non-specific and vaccine-induced humoral immunity against Newcastle Disease Virus (NDV), Infectious Bronchitis Virus (IBV), and Avian Metapneumovirus (AMPV) in already vaccinated hens of a dual-purpose (Lohmann Dual, LD) or a layer genotype (Lohmann Brown Plus; LB). Until 17 weeks-of-age, LD (n = 70) and LB (n = 109) hens were vaccinated against major bacterial and viral diseases and coccidiosis. At 24 weeks-of-age, the hens received either a placebo or an oral inoculation of 1,000 infectious eggs of A. galli and H. gallinarum. Plasma total immunoglobulin (Ig) isotypes (IgY, IgM, IgA) levels and vaccine-induced antibody titers against NDV, IBV, and AMPV were determined from 2 to 18 weeks post-infection (wpi). Infections had no suppressing effect on total Ig isotypes IgY, IgM, and IgA as well as on vaccine-induced antibody titers against NDV, IBV, and AMPV (P > 0.05). Overall, LB hens had higher levels of IgY, IgM, and IgA than those of LD hens (P < 0.05). There were no differences between IBV titers of the two genotypes (P > 0.05). Independent of infection status of the hens, NDV titers were higher in LB hens than in LD hens at wpi 2 (P < 0.05), but not in following weeks (P > 0.05). Uninfected LD hens had lower AMPV titers than their infected counterparts at 6 and 14 wpi (P < 0.05). Regardless of nematode infection, LD hens revealed a higher risk of responding weak to vaccination against NDV (odds ratio = 5.45; P = 0.021) and AMPV (odds ratio = 13.99, P < 0.001) than did LB hens (P > 0.05). We conclude that nematode infections have no adverse effects on non-specific and vaccine-induced humoral immunity in either genotype. LB hens have higher levels of total immunoglobulin isotypes than LD hens. Except for IBV, vaccine-induced humoral immune responses show a dependency on genotype. Dual-purpose hens show lower responsiveness to vaccinations against NDV and AMPV, possibly due to factors associated with increased body fat reserves in this genotype.

[Consequences of high ambient temperatures for lactating dairy cows - an issue under practical conditions in Northern Germany?] / Auswirkungen hoher Umgebungstemperaturen auf laktierende Milchkühe ­ unter praxisüblichen Bedingungen in Norddeutschland von Bedeutung?

OBJECTIVE: The aim of the presented study was to gather quantitative data regarding the impact of high ambient temperatures on dairy cows under practical conditions in southern Lower Saxony. MATERIAL AND METHODS: In summer 2018 (from mid of July to end of September), the climatic conditions in the dairy barn as well as the temperatures of feeds (silages and partial mixed ration, PMR) and feed leftovers were recorded on the Farm for Education and Research of the University of Veterinary Medicine Hannover in Ruthe. Furthermore, daily dry matter intake (of PMR) and milk yield on herd basis as well as respiration rate and rectal temperature of 10 selected cows were measured as indicators for heat stress. RESULTS: During a heat period (daily average temperature up to 27.9° C) dry matter intake (PMR) and milk yield were reduced by about 15 % and 8 %, respectively although ambient temperatures had already been relatively high at the beginning of the observation period (daily average temperature between 19.6 and 23.0° C). Daily dry matter intake of PMR was NEGATIVELY: correlated with daily average temperature-humidity index in the barn (Spearman's correlation coefficient: -0.774, p < 0.0001) and POSITIVELY: correlated with daily milk yield (Spearman's correlation coefficient: 0.766, p < 0.0001). Correlation coefficients were slightly higher when a 1-day time lag was considered (Spearman's correlation coefficient: -0.796 and 0.800, respectively; p < 0.0001). During the heat period hyperthermia (> 39° C) was frequently recorded in lactating cows (up to 100 %). CONCLUSION AND CLINICAL RELEVANCE: The presented results indicate that heat stress in dairy cows may occur to a considerable extent under extreme climatic conditions also in the region of Northern Germany. In consequence, this is associated with a significant decrease in performance. As severe and long-lasting effects of heat stress on health and performance of dairy cows are well described in the literature, especially the temporarily high prevalence of hyperthermia should be taken seriously. Under these circumstances, differentiating between hyperthermia and fever is of special importance for veterinary practitioners.

Resistance Reservoirs and Multi-Drug Resistance of Commensal Escherichia coli From Excreta and Manure Isolated in Broiler Houses With Different Flooring Designs.

Carriage of resistant bacteria and spread of antimicrobial resistance (AMR) in the environment through animal manure pose a potential risk for transferring AMR from poultry and poultry products to the human population. Managing this risk is becoming one of the most important challenges in livestock farming. This study focused on monitoring the prevalence of multi-drug resistance (MDR) bacteria and development of AMR depending on flooring. In two experiments (2 × 15,000 birds), broilers were always divided in two different stables. In the control group, the entire floor pen was covered with litter material and in the experimental group, the flooring system was partly modified by installing elevated slat platforms equipped with water lines and feed pans. Over the whole fattening period, excreta and manure samples were taken (days 2, 22, and 32). In total, 828 commensal E. coli isolates were collected. The development and prevalence of resistance against four different antibiotic classes (quinolones, ß-lactams, tetracyclines, and sulfonamides) were examined by using broth microdilution. At the end of the trials, the amount of manure per square metre was twice as high below the elevated platforms compared to the control group. Approximately 58% of E. coli isolates from excreta showed resistance against at least one antibacterial agent at day 2. During and at the end of the fattening period, resistant E. coli isolates at least against one of the four antibacterial agents were observed in excreta (46 and 46%, respectively), and manure samples (14 and 42%, respectively), despite the absence of antibacterial agent usage. In spite of less contact to manure in the experimental group, the prevalence of resistant E. coli isolates was significantly higher. Birds preferred the elevated areas which inevitably led to a local high population density. Animal-to-animal contact seems to be more important for spreading antimicrobial resistant bacteria than contact to the litter-excreta mixture. Therefore, attractive areas in poultry housing inducing crowding of animals might foster transmission of AMR. In poultry farming, enrichment is one of the most important aims for future systems. Consequently, there is a need for keeping birds not carrying resistant bacteria at the start of life.

Carcass Quality, Meat Quality and Sensory Properties of the Dual-Purpose Chicken Lohmann Dual.

Over 40 million day-old layer line cockerels are culled in Germany each year, due to economic reasons, leading to a recently instigated research focus on the potential of dual-purpose breeds as an alternative to conventional poultry husbandry, especially the practice of culling. This paper aims to explore and assess the dual-purpose chicken breed "Lohmann Dual" (LD) performance (n = 30) and sensory characteristics (n = 48). Carcass and meat quality traits are evaluated, and descriptive sensory analysis of breast muscles is conducted. To define the scope of characteristics, a market sample of "Ross" Line (n = 35) is adducted. LD carcasses are characterized by higher leg than breast yield; carcass, breast and leg weights are higher in Ross. LD meat has a lower pH, differs in color, has higher drip and thawing losses, but lower cooking loss. LD breast muscles are firmer as indicated by shear force measurements, which is confirmed through the sensory analysis. Appearance, odor and flavor differ between the lines. Overall, distinguishable differences are found between both breeds. Further research should focus on the marketing aspect of the dual-purpose line, as some characteristics could draw consumers to this product. Animal welfare and ethical concerns should further be considered when considering dual-purpose breeds as a feasible alternative to culling.

Germline mutation within COL2A1 associated with lethal chondrodysplasia in a polled Holstein family.

BACKGROUND: The bulldog calf syndrome is a lethal form of the inherited congenital chondrodysplasias. Among the progeny of the polled Holstein bull Energy P cases of lethal chondrodysplasia were observed. Pedigrees of the cases and the frequency of 3/8 cases among the offspring of Energy P at our teaching and experimental farm Ruthe (LuFG Ruthe) supported the assumption of a germline mutation with a mosaic of normal and defective sperm. RESULTS: All three malformed calves were examined using necropsy, histopathology and computed tomography scanning. The phenotypic appearance of the affected calves was highly similar; they presented with severe disproportionate dwarfism and reduced body weight. The syndrome was characterized by brachygnathia superior, bilateral palatoschisis, shortening and compression of the body due to malformed vertebrae, in their size reduced and malformed ribs and reduced length of the long bones of the limbs. The bones had small irregular diaphyses and enlarged epiphyses. Whole genome sequencing of one bulldog calf, sperm of its sire Energy P and a normal progeny of Energy P identified a deleterious missense mutation (g.32476082G > A, c.2986G > A, ss2019324576) within COL2A1 on bovine chromosome (BTA) 5. Sanger sequencing confirmed the ss2019324576 variant in the affected calves and sperm of Energy P. This mutation is located within the collagen triple helix repeat and causes an exchange of glycine to serine (p.996G > S) in COL2A1. This private single nucleotide variant (SNV) was present as a gonadal mosaic in sperm of the bull. All affected calves were in a heterozygous state whereas normal half-siblings and all dams of the progeny from Energy P were missing this SNV. Validation in polled Holstein bulls and normal Holstein calves randomly sampled from several herds and from the LuFG Ruthe confirmed this SNV as private. CONCLUSIONS: The identified spontaneous missense mutation within COL2A1 is most likely the cause of lethal chondrodysplasia in the progeny of Energy P through a dominant negative effect. This example suggests that it would be beneficial to conduct whole genome sequencing of sperm from bulls widely used in artificial insemination in order to detect germline mosaicism.