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Non-genetic factors affecting early growth traits and survival in Horro sheep
2002
Abegaz, Solomon | Duguma, G. | Gelmesa, U. | Terefe, F. | Negussie, E. | Rege, J.E.O.
Factors affecting the early growth and survival of indigenous Ethiopian Horro sheep were identified and the influence of each was assessed, based on data collected from 1978 97 from 4031 lambs at Bako Research Centre, Ethiopia. Year of birth, sex, type of birth or rearing, and parity had significant (P < 0.01) effects on birth weight (BWT), weaning weight (WWT), and six month weight (6MWT). With the exception of parity, the same factors affected yearling weight (YWT). Male lambs were heavier by 0.14, 1.1, 1.9, and 4.2 kg than females in BWT, WWT, 6MWT, and YWT. Single born lambs were heavier by about 0.5 kg than multiple born lambs at birth. Lambs born from primiparous ewes were lighter by 0.2 0.3 kg than lambs born from multiparous ewes at birth. With the exception of effect of type of birth and ewe age on survival to 3 and 7 days of age, respectively, year of birth, ewe (dam) age, type of birth, and BWT had significant (P < 0.01) effect on survival from three days to one year of age. The survival of multiple-born lambs was 0.8, 3.7, 8.3, 12.2, and 12.496 lower than single-born lambs at the age of 3, 30, 90, 180, and 365 days, respectively. Lambs born from primiparous ewes had lower survival rates compared to those born from multiparous ewes. Survival was very low in lambs with low BWT and improved with increase in BWT. In general, there are indications that there exists a critical BWT (about 2.6 kg) below which the survival of lambs declines drastically.
Afficher plus [+] Moins [-]Conceptual, methodological and institutional issues in participatory livestock production research
2002
Morton, J. | Adolph, Barbara | Ashley, S. | Romney, Dannie L.
This article discusses major issues that confront attempts to introduce participatory methodologies into livestock production research, based on experiences during two projects in East Africa, and interviews with researchers and others in the region. The extent to which research can be participatory is strongly influenced by the institutional contexts in which it is carried and used, and some of the institutions involved are briefly surveyed. The article then discusses conceptual issues; including the notion of degrees of participation, the underdevelopment of participatory research in livestock compared to crop science, and the reluctance of existing livestock science to deal with multiple-output systems. The relations between participatory research, whole-farm research and livelihoods research, and the role of economic analysis are also explored. Methodological issues at various points of the project cycle are discussed, including: the need to tailor methods to agreed objectives, the role of “PRA toolsâ€, the specific problems relating to participatory trials with livestock, and the role of on-station trials. Institutional issues such as funding procedures and timescales, and reward systems for researchers are generic to all participatory research, but they are perhaps felt more strongly in the livestock sector where they combine with livestock-specific issues.
Afficher plus [+] Moins [-]Productivity and Natural Disease Resistance Potential of Free-ranging Local Chicken Ecotypes in Tanzania
2002
Msoffe, P.L.M. | Mtambo, M.M.A. | Minga, U.M. | Gwakisa, P.S. | Mdegela, R.H. | Olsen, J.E.
This study was carried out to investigate the productivity and the natural disease resistance potential of free-ranging local chickens in Tanzania. A total of 84 adult free-ranging local chicken ecotypes were studied, namely: Mbeya, Morogoro-medium, Ching’wekwe, Kuchi and Singamagazi. Adult body weight, body length, shank length and egg weight were assessed and compared. Average body weight for hens and cocks was 1441g (800 to 2,300g) and 2261g (1000 to 3500g), respectively. Egg weight averaged 41.6g (27 to 72g). Mean body length for hens and cocks was 21.6cm (17 to 26cm) and 24.6cm (21 to 29cm), respectively, and mean shank length 9.7cm (7 to 12cm) and 12.7cm (8.5 to 15cm), respectively. Between ecotypes significant differences were seen in the above parameters. The disease resistance potential was tested on 10 offspring of each ecotype, excluding the Mbeya. Twenty chickens (five from each of the four ecotypes) aged 12 weeks were inoculated with Newcastle disease virus while another 20 aged 20 weeks were inoculated with Salmonella gallinarum. Five chickens per group that were not challenged were used as controls. Following oral, ocular and nasal drop inoculation with Newcastle disease virus, the chickens developed clinical signs of Newcastle disease as from day three after infection. Mortality started on day five after infection, and all but one chicken were dead by day seven after infection. The 20 chickens, infected orally with S. gallinarum, showed clinical signs of fowl typhoid on day three after infection. Mortalities started on day seven after infection and by day 12 after infection 13 chickens had died. Seven birds survived without visible signs of the disease, including all five from the Kuchi ecotype and one each of the Morogoro-medium and Ching’wekwe ecotypes. At necropsy enlarged and congested liver and spleen, and catarrhal enteritis of the small intestines were seen. The surviving birds were sacrificed on day 14 after infection. Neither the sacrificed surviving birds nor the controls showed the above necropsy picture. It was concluded that free-ranging local chicken ecotypes in Tanzania differ in both productivity and disease resistance potential.
Afficher plus [+] Moins [-]Production performance of backyard chicken under the care of women in Charsadda, Pakistan
2002
Farooq, M. | Gul, N. | Chand, N. | Durrani, F.R. | Khurshid, A. | Ahmed, J. | Asghar, A. | Zahir-ud-Din.
Information from 400 randomly selected female farmers was obtained during the year 1997 to assess the production performance of backyard chicken in Charsadda district, North West Frontier Province (NWFP), Pakistan. Only 16.3% of the farmers were regularly vaccinating their flocks. The majority of the farmers initiated immunization only at the time of disease onset (29.7%) followed by those (28.5%) who did not vaccinate. A high proportion (53.3%) provided no housing, 29.8% provide night shelters and 17% had no housing. Average flock size was 22.0 birds, comprising 8.86 chicks, 2.03 pullets and 11.1 layers. The local Desi chicken dominated the flocks (10.2 birds) followed by Fayumi (6.76), Rhode Island Red (4.20) with White Leghorn least popular (0.83 ). Average mortality in a flock was 23.6%. Mortality was higher in layers (28.1%) than in pullets (18.7%) and chicks (24.2%). Significantly higher losses were found in White Leghorn (35.6%) than in Desi chicken (17.5%). Similarly, higher mortality was found in chicken without housing facilities (26.7%) than in those with access to houses (21.6%). Regular vaccination was associated with higher productivity than vaccination at the onset of disease or no vaccination. Average annual egg production was 76.4 for Desi, 109 for Fayumi, 169 for Rhode Island and 153 for White Leghorn. Mean hatchability was 61.2% with an annual frequency of 4.6 settings and 15.1 eggs set per broody hen. Farmer preference for the "local" Desi chicken reflected their greater capacity to survive and adapt to scavenging management systems. Fayumi and Rhode Island chickens appear to merit further studies as breeds that could improve the productivity of scavenging systems, as they had higher egg production and only slightly higher mortality than Desi chicken.
Afficher plus [+] Moins [-]Genetic evaluation of growth traits in a crossbreeding experiment involving two local strains of chickens using multi-trait animal model
2002
Iraqui, M.M. | Hanafi, M.S. | Khalil, M.H. | El-Labban, A.F. | Ell-Sisy, M.
A crossbreeding experiment was carried out between two local strains of Mandarah (MN) and Matrouh (MA) chicken. Thirty-four sires and 400 dams from each strain were used to produce four genetic groups. Body weights of 3067 chicks at hatch (BW0), 4 (BW4), 8 (BW8), 12 (BW12) and 16 (BW16) weeks of age and their daily gains in weight during the age intervals from 0-4 (DG4), 4-8 (DG8), 8-12 (DG12) and 12-16 (DG16) weeks were evaluated. Multi-trait animal model (MTAM) was used to estimate direct additive genetic (GI) and maternal additive genetic (GM) and direct heterosis (HI) effects. Heritabilities were estimated and breeding values (PBV) were also predicted. Estimates of Heritabilities (h2) for growth traits ranged from 0.14 to 0.58. The percentages of GM were in favour of the MA dams and ranged from –1.47 to –6.70 % for body weights and from –1.40 to –7.73 % for gains in weight. Estimates of HI (P
Afficher plus [+] Moins [-]Globalization and the Developing Countries: Emerging Strategies for Rural Development and Poverty Alleviation
2002
Bigman, David
The globalization process and the internal policy reforms that the developing countries have implemented during the past decade have changed the relative prices of practically all their inputs and outputs. Agricultural producers have therefore been forced to change the structure and methods of their production. The objective of this book is to review the impact of globalization on a number of issues. These include the effects of changes in global trading rules and regulations, the removal of trade barriers and the elimination of many country-specific and commodity-specific trade agreements, on the economies of developing countries in general and their agricultural sectors in particular. The book will be of interest to those in the fields of agricultural and development economics.
Afficher plus [+] Moins [-]Wage premiums for on-the-job computer use
2002
Kusmin, Lorin D.
Comparison of different methods in the determination of cholesterol
2002
Sterna, V. (Latvia Univ. of Agriculture, Sigulda (Latvia). Research Centre "Sigra")
The aim of the present study was to determine the level of cholesterol in the milk of the Latvia's cow herds, analyse differences between two different methods of cholesterol determination in milk. Milk samples were obtained from the cows of Latvian Brown and Black and White breeds. The milk fat and protein were analysed by Milkoscan 133, cholesterol content was determined colorimetricaly by Blur procedure with prior lipid extraction by Roese-Gottlieb method and by gas-chromatography method. The obtained results showed that the milk fat content was 4.48+-0.28%, protein was 3.03+-0.09%, cholesterol content in milk was 21.05+-2.01 mg 100 ml*[-1), when assayed by spectrophotometer SF 26 LOMO and 18.29+-1.73 mg 100 ml*[-1), when assayed by gas chromatography. There were no significant differences in cholesterol content between both determination methods.
Afficher plus [+] Moins [-]Changes of biology of the potato late blight pathogen Phytophthora infestans in last years. Review
2002
Bimsteine, G. (Latvia Univ. of Agriculture, Jelgava (Latvia))
Potato is the second important crop in Latvia. The area covered with potato is about 50 thousand hectares. Potato late blight caused by Phytophthora infestans (Mont.) de Bary is the most serious potato disease. Weather conditions in Latvia are very favourable for the development of potato late blight and it is occuring almost every year. The biology of P.infestans was the subject of a number of authors - plant pathologists. Research results about P.infestans population biology and epidemiology are presented in this review, especially focusing on the changes of pathogen biology.
Afficher plus [+] Moins [-]Factors affecting milk calcium and phosphorus content
2002
Kuebarsepp, I. | Henno, M. | Kaert, O. (Estonian Agricultural Univ., Tartu (Estonia))
The purpose of this study to compare milk calcium and phosphorus content of different breeds raised in Estonia. Based on obtained results, different factors and their magnitude of influence on the contents of calcium and phosphorus in milk were studied. On Polula Research Farm five trial groups were made up: Estonian Holstein breed (breeding value 115) (EHF-t), Estonian Holstein breed (breeding value 105...115) (EHF), Red-and-White Holstein breed (RHF), Estonian Red breed (EPK) and Estonian Native breed (EK). Milk samples were collected from five of each trial group twice a month during the year 2001. Calcium and phosphorus contents were determined by using IDF methods 36A:1992 and 42B:1990 in Dairy Laboratory of the Institute of Animal Science.
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