Ruth E. Messikommer

Swiss consumers’ willingness to pay and attitudes regarding dual-purpose poultry and eggs

Abstract Chick culling is an efficient and cost‐effective method in modern poultry farming, but it raises ethical concerns. Dual‐purpose poultry (DP), in which males are fattened and females are used for egg production, is currently the most realistic alternative to culling, as in ovo sexing is not yet viable for practical application. Consumers’ acceptance of DP products and their willingness to pay (WTP) for them have not been studied yet, and we expect that both aspects are closely related to the acceptance of and WTP for products from systems claiming beyond‐conventional animal welfare, such as organic products. Results from a survey conducted among 402 consumers at 8 Swiss supermarkets revealed that the practice of chick culling was largely unknown (75% of respondents). Generally, respondents’ knowledge about poultry production was low. The DP alternative was preferred to chick culling, but no preference emerged between DP and in ovo sexing. Furthermore, the WTP for DP products was proportionally lower for chicken than for eggs, probably because of the different price elasticity between these products. A regression analysis was used to determine the factors influencing consumers’ WTP for DP products. Consumers’ WTP was positively related to knowledge about poultry production, habits tied to purchasing organic or free‐range poultry products, and familiarity with DP products. Therefore, a combination of the DP alternative with an organic label is recommended.

Differences between spent hens of different genotype in performance, meat yield and suitability of the meat for sausage production

The valorization of spent hens via the food chain has some major limitations, which include low meat yield and tough meat. The latter issue can be overcome by producing convenience foods; the first may be alleviated by employing a genotype with higher meatiness. To quantitatively compare two common layer genotypes in production performance, meat yield and sausage quality, 2200 57 weeks old Institut de Sélection Animale (ISA) Warren and Dekalb White hens each were investigated during the last 60 days of egg laying. The hens were housed in an aviary system in 2×10 compartments (10 compartments/each genotype). Measurements included feed intake, laying performance, egg weight and feed conversion ratio as measured per compartment. BW was determined twice on 10 animals per compartment. Finally, two sub-groups of five hens per compartment were slaughtered, meat yield was recorded and bratwurst-type sausages were produced (n=20 per genotype). Fat proportion, cooking loss, connective tissue properties and Kramer shear energy were measured. After 1, 4, 7 and 10 months of frozen storage, oxidative stability (thiobarbituric acid reactive substances (TBARS)) and microbiological status were determined as shelf-life related criteria. ANOVA was performed considering genotype as the main effect. The ISA Warren hens were inferior in laying performance (-11%) and feed conversion ratio (+10%) compared with Dekalb White, but had the same feed intake. The ISA Warren had higher BW and carcass weight than the Dekalb White. Carcass yield was higher by 5.9%. There were 80 g (23%) more meat available for sausage production from ISA Warren compared with Dekalb White. Sausages prepared from meat of ISA Warren hens contained less fat than those from Dekalb White, but showed the same cooking loss. Although the collagen proportion of the sausages produced from ISA Warren was lower than from Dekalb White, collagen solubility was lower and shear energy was higher. During the 10 months of frozen storage, TBARS increased continuously, but not to an extent that would prevent its use as food. The sausages from the ISA Warren genotype had marginally higher TBARS levels during storage. Total colony counts decreased with storage time, with slightly lower values found in the non-spiced sausage material from the ISA Warren hens. In conclusion, when intending to use spent hens as food, ISA Warren are clearly superior to Dekalb White in meat and sausage yield. When processing the meat to sausages, the higher shear energy is probably advantageous.

Effect of replacing dietary vitamin E by sage on performance and meatiness of spent hens, and the oxidative stability of sausages produced from their meat

Abstract 1. A total of 3960 hens (half ISA Warren and half Dekalb White) were housed in 18 compartments with 220 hens each. The effect of replacing dietary vitamin E by sage on productivity, meat yield and oxidative stability of sausages was studied. 2. One third of all animals received either a vitamin E deficient diet (negative control) or diets supplemented with 30 mg/kg α-tocopherylacetate (positive control) or 25 g sage leaves/kg. At slaughter, meat yield was assessed and sausages were produced (n = 12 per treatment). 3. The omission of vitamin E did not impair the oxidative stability of the raw sausage material or the spiced sausages in comparison to the positive control. Sage supplementation improved oxidative stability after 7 m of frozen storage, but not after 1, 4 and 10 m. Spice addition during meat processing had an antioxidant effect regardless of dietary treatment. Diet supplementation of any type did not affect laying performance and sausage meat yield. 4. Feeding antioxidants to spent hens seemed to be not as efficient as in growing chickens, while seasoning with spices during sausage production proved to be a feasible way to delay lipid oxidation.

Carcass and meat quality of dual-purpose chickens (Lohmann Dual, Belgian Malines, Schweizerhuhn) in comparison to broiler and layer chicken types

ABSTRACT Currently, there is an intensive ethical discussion about the practice of culling day‐old layer cockerels. One solution to avoid this practice could be using dual‐purpose types, where males are fattened for meat and females used for egg production. The aim of the present study was to compare fattening performance, carcass conformation, and composition as well as meat quality of Lohmann Dual, a novel dual‐purpose type, and 2 traditional dual‐purpose types (Belgian Malines and Schweizerhuhn) with 2 broiler types and 1 layer type (Lohmann Brown Plus). Broilers included a conventional line (Ross PM3) and a slower‐growing line (Sasso 51) fulfilling requirements of organic farming. Nine birds of each type were fed on a conventional broiler diet. Feed intake and metabolizability of nitrogen and energy were recorded per pen (n = 3), the latter through excreta sampling. For each bird, carcass conformation was assessed, and weights of body, carcass, breast meat, legs, wings, and inner organs were determined. Additionally, breast angle, an indicator for carcass appeal, and skin color were recorded. Meat quality assessment included determinations of thaw and cooking loss, shear force, meat color, and proximate composition of the breast meat. None of the dual‐purpose types (20 to 30 g ADG) performed as well in growth as the intensively growing broiler line (68 g ADG). However, Lohmann Dual could compete with the slower‐growing broiler line (slower growth but better feed efficiency, similar in carcass weight and breast proportion). Also breast angle was quite similar between Lohmann Dual (100°) and the extensive broiler type (115°C) compared to the intensive broiler line (180°). Meat quality was most favorable in the intensive broilers with the smallest shear force and thawing loss, whereas meat quality was not different between the other types. The Schweizerhuhn performed only at the level of the layer hybrid, and the Belgian Malines was ranked only slightly better.

Growth and slaughter performance of two dual-purpose poultry types compared with extensive broiler and layer types fattened for 67 and 84 days

than that caused by recognized “enterohaemorrhagic” STEC serogroups such as O157 and O111. More widespread use of PCRor enzyme-linked immunosorbent assay-based screening tests for the presence of STEC of any serogroup in animal samples will undoubtedly result in increased detection of similar non-O157 outbreaks in the future. This will provide more accurate data on the epidemiology of human STEC disease.

Performance of dual-purpose types in comparison to layer hybrids fed a by-product diet

AIM Identify signals of fat deposition and adaptation through genome-wide scan of the Barbaresca fat-tail sheep. ANIMALS Barbaresca in an ancient Sicilian fat-tail sheep, highly endangered at present. Of the 35 000 heads of 1980, abour 1 300 are left nowadays in 20 flocks. The breed originated from crosses between Barbary sheep from North Africa and the Pinzirita breed at times of the Arab settling in Sicily (9th century). The breed is reared in a very restricted area in central Sicily on smalland medium-sized farms under a semi-extensive farming system. It is a dual-purpose breed: milk for cheese and meat. Barbaresca is one of the only two fat-tail sheep of Italy. METHODS Genotypic data were obtained with the OvineSNP50K array. Fst values of differentiation for 43072 markers were calculated in pairwise comparisons of Barbaresca with each of 13 Italian thin tail breeds. Fat-tail sheep still represent twenty-five percent of the world sheep population; they are predominant in pastoral, transhumant and low input systems. In Western countries and in high input systems they are generally endangered. Fat-tail sheep preserved genetic variability for functional adaptation. The identification of the genes with a role in the fat-tail phenotype contributes to the understanding of the physiology of fat deposition as well as the mechanisms of adaptation and is essential for maintaining future breeding options.uf071 Heritability estimates for the 1st litter size, pregnancy rate and whelping success were low (0.05-0.14) uf071 Grading size and quality had moderate heritability estimates 0.27 and 0.21, respectively uf071 Genetic correlations between animal grading size and fertility traits were unfavourable (from -0.15 to -0.53) uf071 Grading quality and guard hair coverage had antagonistic relationships with all the studied fertility traits (from -0.21 to -0.54) Genetic parameters of fertility and grading traits in Finnish blue foxTrabajo presentado al: 68th Annual Meeting of the European Federation of Animal Science (EAAP). (Tallin, Estonia. 28 agosto - 2 septiembre).As genomic selection has been used already for several years, it has become evident that the validation of genomic evaluations relying on traditional animal models is becoming unsuitable. The GEBV validation test recommended by Interbull is cross-validation based on the forward prediction. It was designed at the time when the multi-step genomic evaluation was the standard method.xa0 The aim of this study was to take a closer look on accuracy and stability of (G)EBVs. Validations for GEBVs were done using yield deviations (YD) or daughter yield deviations (DYD) calculated with single-step GBLUP instead of EBV model. Moreover, we studied the stability of (G)EBV estimations in consecutive evaluations. We used Nordic Holstein 305 days production data containing ca. 7.3 million cows with 15.6 million observations.xa0 Genotypes were available for 30056 animals which had either records or offspring in the full 305d data. The test setup consisted of four data sets: the full data, called data 0 , included calvings up to March 2016. Three reduced data sets were data -1 , data -2 , and data -3 , from which one year of calvings was deleted at a time.xa0 This allowed studying the accuracy of predictions by production years, and also the stability of (G)EBV estimates across lactations. The bull validation was a regression of DYD EBV on PA data-3 or, for GEBV data-3 , regression of DYD GEBV on GEBV data-3 .xa0 The results suggested that after use of genomic selection the DYD from EBV model become biased and that GEBVs validated using DYDs from the BLUP model might receive too low reliability. The validation reliability for protein GEBV (r 2 ) was 0.34 using DYD from EBV model and 0.36 using DYD from ssGBLUP. Similarly, when making cow validations, it might be advisable to use YDs calculated from ssGBLUP for the validation.xa0 The r 2 in GEBV validations using YD from ssGBLUP were on average 5 % units higher compared to validations using YDs from the EBV model.Trabajo presentado al: 68th Annual Meeting of the European Federation of Animal Science (EAAP). (Tallin, Estonia. 28 agosto - 2 septiembre).