M. Siegmund-Schultze

Effects of the Genetically Reduced Feather Coverage in Naked Neck and Featherless Broilers on Their Performance Under Hot Conditions

Under hot conditions, contemporary commercial broilers do not reach their full genetic potential for growth rate, body weight (BW), or breast meat yield because dissipation of their excessively produced internal (metabolic) heat is hindered by the feathers. Therefore, it was hypothesized that heat stress can be alleviated by using the naked-neck gene (Na) or the featherless gene (sc). The study consisted of 4 experimental genetic groups (fully feathered, heterozygous naked neck, homozygous naked neck, featherless), progeny of the same double-heterozygous parents (Na/na +/sc), and commercial broilers. Birds from all 5 groups were brooded together until d 21 when one-half of the birds from each group were moved to hot conditions (constant 35 degrees C), and the others remained under comfortable conditions (constant 25 degrees C). Individual BW was recorded from hatch to slaughter at d 45 and 52 at 25 and 35 degrees C, respectively, when breast meat, rear part, heart, and spleen weights were recorded. Body temperature was recorded weekly from d 14 to 42. Feather coverage significantly affected the thermoregulatory capacity of the broilers under hot conditions. With reduced feather coverage (naked-neck), and more so without any feathers (featherless), the birds at 35 degrees C were able to minimize the elevation in body temperature. Consequently, only the featherless birds exhibited similar growth and BW under the 2 temperature treatments. The naked-neck birds at 35 degrees C showed only a marginal advantage over their fully feathered counterparts, indicating that 20 to 40% reduction in feather coverage provided only limited tolerance to the heat stress imposed by hot conditions. Breast meat yield of the featherless birds was much greater (3.5% of BW, approximately 25% advantage) than that of their partly feathered and fully feathered counterparts and the commercial birds under hot conditions. The high breast meat yield (at both 25 and 35 degrees C) of the featherless broilers suggests that the saved feather-building nutrients and greater oxygen-carrying capacity contribute to their greater breast meat yield. Because of these results, further research on genetically heat-tolerant broilers should focus on the featherless phenotype.

SMALL RUMINANT PRODUCTION IN TWO MIXED-FARMING SYSTEMS OF SOUTHERN ETHIOPIA: STATUS AND PROSPECTS FOR IMPROVEMENT

Small ruminants are an integral part of mixed-farming systems throughout southern Ethiopia. Yet, they have received little research attention or institutional support. Characterizing the existing small ruminant production systems and analysing their production constraints are important tools to diagnose the status and trends of the systems, and thus to identify areas for future interventions. A survey was conducted between April and July 2004 in the Adilo and Kofele areas of the southern mixed-farming systems of Ethiopia to explore reasons for keeping small ruminants and to evaluate the existing status of and the prospects for the small ruminant sector. Additional information was obtained during discussions with key informants who had experience of small ruminant keeping. Small ruminants fill several roles in the study area. However, the principal purpose of keeping sheep and goats was to generate cash income. Sheep milk consumption was widespread around Kofele unlike most agricultural systems in the country. Nearly all respondents in Adilo reported fattening their sheep before sale, while such a practice was uncommon in Kofele. Informal insurance schemes were evolving among the sheep keepers in Adilo, and these can be considered as entry points for future interventions. The common problem identified from both individual interviews and group discussions was feed shortage. The identification of alternative feed resources and strategic feeding management might be options for development. Small ruminant disease was the major constraint in Kofele, where marshy areas are increasingly assigned for grazing in the rainy season as suitable land is more and more used for cropping. The growing demand for meat from small ruminants, the improving transportation infrastructure and the experience of farmers in small ruminant keeping are providing opportunities to enhance the contribution of the sector. A thorough monitoring of the productive and economic performance of small ruminants is required to capture the full picture of their contribution thereby directing possible intervention areas to maximize benefits to the farmers.

Economic performance of small ruminants in mixed-farming systems of Southern Ethiopia

This study evaluates the household income contribution and the profitability of traditional small ruminant enterprises in two mixed-farming systems of southern Ethiopia (viz. Adilo and Kofele). Small ruminant production is an integral part of mixed systems in the Ethiopian highlands. The assessment of the current economic performance of small ruminants indicates production-related opportunities and constraints and provides baseline data against which the success of future interventions can be measured. Detailed information on economic parameters was gathered through a 1-year period of flock and household monitoring (155 households) between September 2005 and August 2006. Structured surveys were conducted with the participating households to elicit information on income-expense details of small ruminant and other agricultural enterprises. Small ruminants contributed considerably to cash income and to a limited extent to human nutrition especially when other sources were in short supply. The annual profit per animal ranged from 20 to 37 Ethiopian Birr. The return to capital was 17% in Kofele and 29% in Adilo, with both values vastly exceeding the national interest rate. The sale of small ruminants contributed to 39% and 23% of total farm cash income among small ruminant keepers in Adilo and Kofele, respectively. Sale prices are highest before holidays. Researches should target at how to use available feed resources in a timely and cost-effective fashion to make use of the seasonal market opportunities.

Caracterização e avaliação da pastagem do rebanho de agricultores familiares do nordeste paraense

No Nordeste Paraense alguns agricultores familiares tem implantado pequenas areas de pastagens e manejado pequenos rebanhos com o objetivo de aplicar eventuais ganhos obtidos com os cultivos, criando uma poupanca a ser utilizada nas necessidades futuras da familia ou da propriedade. Ha indicios de problemas nas pastagens e no rebanho que limitam tanto a producao e a sustentabilidade da pecuaria, como comprometem os cultivos agricolas que realmente sustentam a propriedade. Este estudo tratou de identificar as principais limitacoes e propor alternativas de manejo que sejam economica e ecologicamente mais sustentaveis. Na primeira fase do estudo, numa amostra ao acaso de 38 propriedades, descreveu-se o manejo da pastagem e do rebanho, e na segunda, numa amostra menor, de doze propriedades e por um periodo de 29 meses, avaliou-se o potencial desses dois componentes. As propriedades estudadas desenvolvem uma pecuaria de baixa produtividade. Devido a baixa fertilidade do solo e o deficiente manejo, as pastagens nao suprem os alimentos necessarios ao rebanho, tanto em quantidade como em qualidade. Tambem foram identificadas deficiencias no manejo do rebanho, proprias de sistemas extensivos. Contudo, as limitacoes podem ser solucionadas com praticas amplamente conhecidas de manejo da pastagem (como formacao, manutencao e manejo) e do rebanho (reproducao, manejo de bezerros e sanidade em geral). Novos modelos de exploracao tambem foram sugeridos.

Prevalence of mastitis and brucellosis in cattle in Awassa and the peri-urban areas of two smaller towns.

The prevalence of mastitis and brucellosis in urban and peri‐urban settings was studied in Awassa and two smaller nearby towns in southern Ethiopia, because milk‐born diseases are causing a risk for human health, besides direct impacts on animal production. Mastitis was investigated by examining 80 cows (320 udder quarters) using California mastitis test (CMT) and somatic cell count (SCC). The prevalence of brucellosis was assessed by sampling 177 cattle in Awassa and its peri‐urban areas using serological methods. Logistic regression was used to analyse risk factors associated with mastitis. Prevalence of clinical mastitis on quarter level was 0.9%, and 1.9% of quarters were non‐functional or blocked. Prevalence of sub‐clinical mastitis at quarter level in urban and peri‐urban areas was significantly different (P < 0.05). Cows in large herds and at advanced lactation number were associated with higher risk of infection. The percentage of quarters positive on CMT (42.5%) was close to the percentage‐positive detected by SCC (41.2%). Prevalence of brucellosis was 3.9% in the peri‐urban area, while no brucellosis cases were detected in Awassa. More frequent use of artificial insemination in the urban than in peri‐urban area might have contributed to the absence of brucellosis in the urban location. The extent of mastitis is, however, a threat to the dairy enterprise in and around Awassa. Pasteurization of milk and milk products is indicated in some parts of the area because of the danger of brucellosis.

Constraints and challenges of meeting the water requirements of livestock in Ethiopia: cases of Lume and Siraro districts

Compared to the total water use in livestock production systems, water for livestock drinking is small in amount but is an important requirement for health and productivity of animals. This study was carried out to assess constraints and challenges of meeting drinking water requirements of livestock in rural mixed smallholder crop–livestock farming districts in the Ethiopian Rift Valley area. Data was collected by individual interviews with randomly selected respondents and farmer group discussions. Farmers ranked feed and water scarcity as the two most important constraints for livestock husbandry, although the ranking order differed between districts and villages. Poor quality water was a concern for the communities in proximity to urban settlements or industrial establishments. Water provision for livestock was challenging during the dry season, since alternative water sources dried up or were polluted. Though rainwater harvesting by dugout constructions was practiced to cope with water scarcity, farmers indicated that mismanagement of the harvested water was posing health risks on both livestock and people. A sustainable water provision for livestock in the area, thus, depends on use of different water sources (intermittent or perennial) that should be properly managed. Industrial establishments should adopt an environment-friendly production to minimize pollution of water resources used for livestock consumption. Technical support to farmers is required in proper design and use of existing rainwater harvesting systems. Further investigations are recommended on effect of poor quality water (perceived by farmers) on performance of livestock.

Impact of Support Centres for Social Farming on Benefits from Livestock in Northern Europe

Social farming uses farm activities as a means of promoting human mental and physical health. As organized social farming became more professional, some European countries introduced support centres to assist in its development. This paper reports on a study that examined the experience of such support centres in the Netherlands, Norway and Flanders to assess their current activities and their impact on social farmers who kept livestock. Information was gathered through interviews and online questionnaires. The Dutch farmers had generally restructured their livestock activities to meet some of the demands of social farming, whereas the Flemish farmers had not adapted their system, as they derived their main income from farming rather than from social care.