Klaus Horsted
Aarhus University
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Acta Agriculturae Scandinavica Section A-animal Science | 2006
Klaus Horsted; Marianne Hammersh⊘j; John E. Hermansen
Abstract Two experiments were conducted to study the effects of different forage crops on productivity and some egg quality parameters of small flocks of organic laying hens fed whole wheat or concentrates. Each experiment was carried out in a split plot design with two different forage crops and two types of supplementary feed (typical concentrate for organic layers versus whole wheat) with three replications. In the first experiment the tested forage crops were of a well-established grass/clover and a mixture of forbs (Fagopyrum esculentum, Phacelia tanacetifolia and Linum usitatissimum). In the second experiment the tested forage crops were a well-established grass/clover and chicory (Cichorium intybus cv. Grassland Puna). The results on productivity and egg quality suggest that laying hens consume large amounts of foraging material when accessible. In nutrient restricted hens (wheat-fed) the forage may yield a substantial contribution to the requirements of amino acids and metabolizable energy although productivity parameters and measurements on dry matter in albumen showed that wheat-fed hens, on a short-term basis, were not able to fully compensate for the lack of protein and amino acids by increased foraging. Of the forage crops investigated especially chicory seems to contribute to the nutrition of the hens. Measurements on eggshell parameters showed that oyster shells together with foraging material were sufficient to meet the hens’ calcium requirements. Yolk colour clearly revealed that laying hens consume large quantities of green fodder irrespective of the type of supplementary feed. Yolk colour from hens with access to chicory tended to be darker, of a redder and less yellow hue compared with grass/clover fed hens, which is considered a positive quality.
Acta Agriculturae Scandinavica Section A-animal Science | 2005
Klaus Horsted; Judith Henning; John E. Hermansen
Abstract The effects of strain, sex and age on live weight, slaughter weight and sensory characteristics of organically reared broilers in orchards are presented. A total of 450 broilers of three different strains (I 657, Light Sussex, New Hampshire) were reared in an organic research orchard. Half of each strain was slaughtered at 91 days and the other half at 120 days. All broilers were weighed and a clinical welfare assessment was made at slaughter. A trained sensory panel evaluated the breast meat in relation to flavour, smell and texture characteristics defined by the panel. At both 91 and 120 days of age the commercial breed I 657 was significantly heavier than the slower growing strains. Males were significantly heavier than the females across strains. Weight ratios between males and females were nearly the same at both slaughter ages in I 657, whereas weight ratios increased significantly at 120 days in Light Sussex and New Hampshire. No overall effect of strain was found on the flavour and smell of the breast meat. However, the age-related changes in tenderness and toughness differed significantly between strains, since the commercial strain tended towards a tougher and less tender consistency with age, whereas the opposite was the case for the slower growing pure breeds. The positive flavour of salt was significantly improved at 120 days across strains with females having a saltier flavour than the males with age. The positive flavour of sweet corn was improved in the meat from the males, whereas the positive smell of sweet corn was significantly improved in both males and females. No negative effects of age were found. In conclusion, broilers were tastier when slaughtered at 120 days compared with 91 days. The development in meat tenderness was related to strain, and weights at slaughter were related to both strain and sex.
Worlds Poultry Science Journal | 2015
Mette Vaarst; Sanna Steenfeldt; Klaus Horsted
The concept of ‘sustainability’ or ‘sustainable development’ is multi-dimensional, encompassing economic, environmental, social, and institutional governance aspects. The theoretical framework for this article on sustainability in poultry production is built on this multi-dimensional understanding of the concept, acknowledging that it is complex and contested. It is challenging to analyse or discuss the sustainability of one single sector within agriculture, because this sector is part of a global food system, and a systems approach is necessary. This article gives examples of elements which link to one or more of the four aspects, e.g., pollution and antibiotic use, biodiversity (environmental aspects), conditions for farm workers and animal welfare (social aspects), governance of the food chain (institutional aspects), and the development of poultry from a valuable food to a cheap staple food throughout major parts of the world (economic aspects). There are numerous potential pathways for sustainable development of poultry production. Poultry are living, sentient animals that can be well integrated into many different types of urban and rural farming systems, where they benefit from and contribute to such systems and to the livelihood of households around the globe, with special emphasis on women. Furthermore, local production provides potential for production with minimum transport and, concomitantly, minimum usage of fossil fuels. Among the terrestrial animals, poultry has the best conversion rate of feed to human food and the smallest environmental footprint in terms of energy and water use per kg meat or eggs produced.
British Poultry Science | 2010
Klaus Horsted; B.H. Allesen-Holm; John E. Hermansen
1. Studies on the sensory profiling of male broiler breast meat were carried out to evaluate the effect of two very different broiler breeds (JA757 and New Hampshire), two different feed types (broiler and grower feed) and age at slaughter (82 and 110 d). 2. The sensory profiling consisted of a pilot study, 4 training sessions, and finally the assessment. During the training session a panel of 9 assessors defined 17 attributes, which were used to describe the smell, texture and flavour of the breast fillets. Each attribute was evaluated on a 15-cm unstructured line scale. 3. The breast meat became significantly less hard, and more juicy and tender in the New Hampshire at 110 d of age, whereas the opposite was found in JA757, which also acquired a more “sourish” flavour with age. The smell of “sweet/maize” and “bouillon” became weaker with age in JA757, but not in New Hampshire. 4. Several significant differences in relation to the main factors of breed and age were found. The traditional broiler hybrid JA757 did best for most smell and flavour attributes, whereas New Hampshire did best for the texture attributes. Age had a negative effect on the flavours and smell attributes “fresh chicken”, “neck of pork” and “sweet maize”, but a positive effect on the texture attribute “crumbly”. In addition meat was more “stringy” at 110 d of age. 5. The flavours “neck of pork” and “umami” were significantly improved when JA757 was fed on the broiler feed and when New Hampshire was given the grower feed. The meat smelt more “sourish” at 82 d of age and less “sourish” at 110 d of age when the grower feed was consumed. Meat was significantly harder and stringier when JA757 was fed on the grower feed. This was not the case for New Hampshire. In general, the meat was significantly less crumbly and stringier with the grower feed. 6. Overall a very distinct difference in sensory profile was found between the two breeds. In addition different slaughter ages and feeding strategies should be taken into consideration in a niche production based on alternative genotypes.
Acta Agriculturae Scandinavica Section A-animal Science | 2013
Anne Grete Kongsted; Klaus Horsted; John E. Hermansen
Abstract The nutritional contributions from free-range foraging, growth, feed conversion and behaviour were investigated in 36 growing pigs foraging on Jerusalem artichokes (JA) and fed concentrates restrictedly (30% of energy recommendations) or ad libitum. Compared to the ad libitum fed pigs, the pigs fed restrictedly had a significant lower daily gain (560 vs. 1224 g pig−1), improved feed conversion ratio (17.6 vs. 42.8 MJ ME concentrate kg−1 live weight gain) and spent more time foraging JA tubers (7.9 vs. 1.1%). It is estimated that pigs fed restrictedly found approximately 60% of their energy requirement from foraging in the range.
Parasitology | 2014
Gustavo Fonseca de Almeida; Stig M. Thamsborg; Alda Maria Backx Noronha Madeira; Jorge F.S. Ferreira; Pedro Melillo de Magalhães; Luiz Carlos Demattê Filho; Klaus Horsted; John E. Hermansen
Due to an increasing demand for natural products to control coccidiosis in broilers, we investigated the effects of supplementing a combination of ethanolic extracts of Artemisia annua and Curcuma longa in drinking water. Three different dosages of this herbal mixture were compared with a negative control (uninfected), a positive control (infected and untreated), chemical coccidiostats (nicarbazin+narazin and, later, salinomycin), vaccination, and a product based on oregano. Differences in performance (weight gain, feed intake, and feed conversion rate), mortality, gross intestinal lesions and oocyst excretion were investigated. Broilers given chemical coccidiostats performed better than all other groups. Broilers given the two highest dosages of the herbal mixture had intermediate lesion scores caused by Eimeria acervulina, which was higher than in broilers given coccidiostats, but less than in broilers given vaccination, oregano and in negative controls. There was a trend for lower mortality (P = 0·08) in the later stage of the growing period (23-43 days) in broilers given the highest dosage of herbal mixture compared with broilers given chemical coccidiostats. In conclusion, the delivery strategy of the herbal extracts is easy to implement at farm level, but further studies on dose levels and modes of action are needed.
Journal of the Science of Food and Agriculture | 2011
Anne Grete Kongsted; Chris Claudi-Magnussen; John E. Hermansen; Klaus Horsted; Bent Hindrup Andersen
BACKGROUND The objective was to compare the performance and meat quality of two different pig breeds: the modern crossbred Landrace × Yorkshire (LY) and the traditional Danish Black-Spotted (BS) breed. The LY gilts and four of the BS gilts were inseminated with semen from Duroc (D) boars; the remaining BS gilts were served by BS boars. The experiment was performed on 26 gilts over 2 years. RESULTS The BS breed in general had smaller litter sizes and weaned on average in terms of kg piglet 35% less than the modern breed combination. Crossbred piglets of BS × D had growth rates from birth to weaning comparable with piglets of LY × D. BS first parity sows were significantly fatter and less meaty, and the meat was significantly redder and darker compared to LY. The sensory profiling revealed increased sweetness, crumbliness and tenderness in BS. Further, the fat of the BS breed seemed to be characterized by a special nutty taste. CONCLUSION The traditional breed has lower productivity and thereby higher costs of production compared to the modern genotypes. On the other hand, the meat and fat of the traditional purebred have special characteristics that might trigger a market premium.
Organic agriculture | 2015
Gustavo Fonseca de Almeida; Klaus Horsted; E. A. Figueiredo; Stig M. Thamsborg; M. B. Molento; L. C. Demattê Filho; John E. Hermansen
With the purpose to identify alternatives to the use of oil seed crops and cereals in broiler feeding, we interviewed 21 family farmers raising broilers in alternative systems located in three relevant sites for the poultry industry in Brazil. Two groups in the south (Parana and Rio Grande do Sul) were organized in cooperatives raising slow-growing broilers in free-range systems. The third group was linked to a broiler company in the state of Sao Paulo producing antibiotic-free (AF) broilers in intensive systems. Individual assessments were performed through surveys with semi-structured questions. Nutrient supply was heavily dependent on maize and soy. Free-range broilers were normally raised with access to outdoor areas in permanent paddocks with very little vegetation available. In the three sites, the finishing period of broilers was the production stage with higher feed supplementation. In addition, farmers producing AF broilers highlighted subclinical coccidiosis as of high economic importance. Production of slow-growing broilers in free-range systems would benefit from local resources for the finishing period. Novel feeding strategies for broilers are suggested based on the farmers’ report, agroecological site characteristics, and production systems.
Reference Module in Food Science#R##N#Encyclopedia of Meat Sciences (Second Edition) | 2014
John E. Hermansen; Klaus Horsted; Anne Grete Kongsted
Although organic agriculture is one of the fastest growing sectors of agricultural production, the market share of organic meat products is still very limited, due to their considerable higher prices than that of conventional products. Aspects related to feed consumption (organically produced feed with lower yields and less options to optimize feed rations) together with increased demands related to rearing of the livestock is responsible for the higher price. Thus, demand for access to outdoor areas means that systems for pigs and poultry in particular differ very much from conventional ones. Poultry products, in particular, differ markedly in meat quality from conventional ones due to huge differences in their genotype and harvest age. Quality dimensions such as animal welfare, environment, and less use of antibiotics are acknowledged by consumers.
Livestock Production Science | 2004
John E. Hermansen; Karin Strudsholm; Klaus Horsted