Crossing local breeds with exotic breeds may be an option for increased livestock productivity. However, there is a risk for endangerment of the local breeds. One such case is in Kenya where the imported Dorper breed is used for crossbreeding with Red Maasai sheep. The aim of this study was to investigate farmers' trait preferences as a basis for determination of breeding objectives for Red Maasai and Dorper sheep at two sites, Amboseli and Isinya, in Kenya. Within their own flock, each farmer identified three ewes representing the best, average and poorest within each breed group: Red Maasai, Dorper and Crosses. Farmers gave reasons for their ranking. Body measurements and weights were also taken. At the harshest site, Amboseli, differences between breed groups in body weight were small and breeds were equally preferred. In Isinya, where environmental conditions are better and farmers are more market oriented, Dorper and Crosses had significantly higher body weights and market prices and were thus preferred by the farmers. Red Maasai were preferred for their maternal and adaptive traits. Breeding objectives should emphasize growth traits and milk production in both breeds at both sites. Body condition needs to be specifically considered in the breeding objectives for sheep in Amboseli, whereas adaptive traits need to be generally emphasized in Dorper.

Uniquely selected breeds bred over thousands of years of domestication in a wide range of environments have been declared extinct over the last century. Still more breeds are at risk of becoming extinct and the rate continues to accelerate. Assessing the current status and possible future dynamics of livestock breeds is therefore a critical step in the management of Animal Genetic Resources (AnGR). This study applies a qualitative approach to comprehensively analyze cattle genetic resources in selected countries in order to better understand the risk status of cattle breeds and those that need to be considered extinct and/or quasi-extant. The status of each breed, i.e., not at risk, critical, endangered and extinct, was verified using information available at the Domestic Animal Diversity Information System (DAD-IS) web site, as well as cattle statistics (where available) and a breed survey. In most examples, breeds listed as extinct have played important roles in the development of new breeds, and should not be classified as extinct, unless proven otherwise, given that even breeds existing in vivo are developing. Therefore, a new risk status quasi-extant for this category of cattle breeds is suggested. In addition, based on the findings of this study, the concept of breed needs to be questioned as relates to it being a good measure of genetic diversity. Further investigations of the situation of cattle breeds (and other livestock species) in more countries/continents using similar categories are deemed necessary.

Reyna Creole cattle in Nicaragua comprise about 650 purebred animals, and the breed has been shown to have a high level of inbreeding. To characterize the breed, as basis for a conservation program, information from two herds on birth weight (BW, n = 1097), age at first calving (AFC, n = 449) and calving interval (CI, n = 1,347) was analysed. Overall averages were 27.8 kg for BW, 37.4 months for AFC and 424 days for CI. Large differences between the herds were observed for all traits. Thus, there would be opportunities for management interventions to improve reproduction results. The heritability for BW was 0.34. For CI, the heritability of 0.20 and the additive genetic standard deviation of 36 days were comparatively high values. No genetic variation was found in AFC. Estimated inbreeding effects were associated with large standard errors due to the small size of the data and incompleteness of pedigrees. Nevertheless, significant effects were shown of dam inbreeding level on all traits. For each percentage of increased inbreeding, BW decreased by 0.06 kg, AFC increased by 3.5 days and CI increased by 1.4 days. The effects of the inbreeding level of the individual itself were not significant. The relatively good reproduction traits of Reyna Creole cattle shown in this study, despite high inbreeding levels, will be supplemented with a characterization of milk production traits.

Reyna Creole cattle originated from Bos taurus cattle brought to Latin America during the Spanish colonization in the fifteenth century and are the only remaining local breed in Nicaragua. However, the current genetic status of this breed is unknown. Therefore, the population structure of three recorded Reyna Creole herds in Nicaragua was studied to estimate their level of inbreeding, effective population size, and generation intervals. Data from 2,609 animals born between 1958 and 2007 were analyzed. A pedigree completeness index higher than 0.8 was required to obtain reliable estimates of the level of inbreeding, and this criterion was met for 367 animals (14%) in two herds. The average level of inbreeding was 13.0%, with values ranging from 0% to 43.8% for individual animals. One of the herds had an average inbreeding level of 21.6%, primarily due to long periods in which the same bulls were used for mating, leading to excessive frequencies of matings between closely related animals. The effective population size differed between years and ranged from 28 to 46 animals, showing that the Reyna Creole cattle breed is endangered, close to critical status. The average generation interval was 6.9 years with values as high as 19.1 years for some sires that were used for artificial insemination over a long period of time. Due to the high level of inbreeding and small population size, urgent actions are required for the development of a breeding program to protect the breed and support its sustainable utilization.

Four cattle breeds indigenous to western and south-western Ethiopia - Abigar, Gurage, Horro and Sheko - were included in a study of the perceptions of smallholder cattle keepers regarding cattle management, production levels and constraints for production. A semi-structured questionnaire was used and 60 cattle keepers from each of the four areas were interviewed. Diseases were reported as the main constraint to cattle production by a majority of livestock keepers in all areas except in the Sheko area, where over-stocking was the main constraint. Among diseases, trypanosomosis was the main livestock disease according to more than half of Gurage, Horro and Sheko keepers, whereas anthrax was most important in the Abigar area. Gurage had highest age at first calving, longest calving interval and also the lowest milk production, whereas Sheko and Abigar had the most favorable characteristics both for milk production (600-700 kg) and fertility (age at first mating 3-3.5 years and above 8 calves/cow). Cattle keepers in the Sheko area reported relatively less problems with cattle diseases compared to the other areas, especially regarding trypanosomosis. Abigar showed a different disease pattern than the other breeds and may also have advantages as regards trypanotolerance.

We used a partial-budget analysis to evaluate profitability of different management strategies of three Genotypes of sheep in a 2 x 2 x 3 factorial experiment conducted at Debre Berhan research station in the central highlands of Ethiopia. This involved two anthelmintic-treatment levels (treated vs. non-treated), two supplementary nutrition levels (protein-energy supplementation yes/no) and three genotypes: indigenous Menz (n = 40), 50% Awassi x 50% Menz crosses (n = 38) and 75% Awassi x 25% Menz crosses (n = 3 1). All sheep were exposed to natural sub-clinical helminthosis challenge. Supplemented sheep were offered a concentrate mix daily on an individual basis. Anthelmintic-treated sheep were drenched with fenbendazole against nematodes and with triclabendazole against trematodes. Data were collected during the experimental period (for 10 months from similar to 1 year of age) on feed intake, live weight, eggs per gram (EPG) of faeces, packed-cell volume (PCV), wool weight, and adult-worm burden. Actual market input and output prices were recorded. Supplemented sheep had significantly higher marginal profit (MP) per sheep than nonsupplemented sheep (ETB1 33 vs. 4). Likewise, anthelmintic treated sheep performed significantly better than their non-treated contemporaries (NIP = ETB 28 vs. 8). The 75% Awassi crosses were least profitable. (C) 2008 Elsevier B.V. All rights reserved.

A major principle of animal breeding is to select those animals to become parents that will improve the genetic level in the next generation the most. For this purpose we need to identify animals with the best genes. In most situations this amounts to finding animals with the best additive genetic effects (or breeding values). The breeding value is not a measure of how good an animal is in itself, but rather of the effect its genes will have in the population.

We evaluated the profitability of anthelmintic treatment and nutritional supplements using partial budget analysis on 108 weaned Menz ( n=39), 50% Awassi-Menz ( n=38) and 75% Awassi-Menz ( n=31) crossbred sheep genotypes kept on-station under subclinical helminthosis at Debre Berhan, Ethiopia. Data were collected on feed intake, live weight, eggs per gram of faeces (EPG), packed cell volume (PCV), fleece weight, slaughter weight, carcass weight, dressing percentage, and adult worm burden counts. Input and output prices were recorded. Anthelmintic treatment reduced EPG and worm burden, which was consistent with significantly higher PCV, slaughter and carcass weights for treated than for non-treated sheep ( P<0.05). Supplemented sheep had higher (P<0.0001) weight gain, carcass weight and dressing percentage than non-supplemented sheep. Anthelmintic treatment resulted in a marginal profit (MP) of 13.46 ETB † per sheep whilst supplementation resulted in MP of 17.13 ETB per sheep. MP per sheep was higher for Menz than the crosses due to the higher skin price of Menz sheep. MP from anthelmintic treatment increased as exotic blood level increases suggesting the higher dependence of the crossbreds on anthelmintics. Sheep breeding objectives were discussed in relation to low input system.

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