This paper describes a study aimed at evaluating the effect of selecting sires based on their breeding values for milk yield estimated in their countries of origin on reproductive performance of their daughters on large-scale dairy farms in Malawi. To do this an analysis was done using 2362 records of purebred Holstein Friesian cattle kept in Central and Southern Malawi from 1986 to 1996. Fixed effects of sire group, herd, year and season of calving were tested and random effects of dam and cow were included in the statistical model applied. (Co)variance components were estimated through the restricted maximum likelihood (REML) procedure. Mean number of services per conception (NSC) was 1.50, gestation interval (GI) was 277days, calving interval between first and second parity (CI1) was 416 days, calving interval between second and third parity two and three (CI2) was 408 days, and age at first calving (AFC) was 32.5 months. In general the majority of the reproductive traits were affected by the non-genetic factors of herd, year and season. Sire group, a proxy of the breeding strategy, had a significant effect on AFC (p<0.01) and CI2 (p<0.05). Factors that had significant effects (p<0.01) on most of the reproductive traits in the study were herd, year of insemination, year of calving, and season of insemination. Phenotypic correlation between NSC and AFC was 0.19, between NSC and GI was -0.05, while that between NSC and CI2 was 0.14. Heritability estimates for NSC, GI, CI1, and AFC were, 0.04, 0.10, 0.001, and 0.20, respectively. The high variation due to non-genetic factors and the low heritability estimates for the reproductive traits indicate that much improvement could be made through improved management, husbandry practices, and strategically utilizing environmental factors.

Range forages consumed by free-range goats are commonly deficient in protein, energy and minerals resulting in low productivity of the goats. The main objective of this study was to evaluate the effect of whole pumpkin seed meal supplementing diet on growth performance and semen quality of free-range goats. Thirty Malawian local bucks with an initial weight of 12.4±0.3 kg and age of 6 months were studied in completely randomised design. The treatments were: free-grazing with either supplementing diet of pumpkin seed meal or soybean meal and grazing only. The supplementing diets were mixed with maize bran to make them comparable. The supplementing diets were offered to goats (500 g each goat) before grazing (7:00 am) in individual pens followed by free graze for 7h. The experiment ran for 150 days. The measurements included: feed and refusals of the supplementing diet, live body weight, scrotal circumference and semen quality characteristics. The intake of supplementing diets was high in bucks consuming soybean supplementing diet than pumpkin seed meal supplementing diet (P = 0.0489). Bucks supplemented with either soybean or pumpkin seed meal had higher final weight and average daily gain (P < 0.05) than the non-supplemented goats. However, the final live body weight and average daily gain did not differ (P = 0.639) between goats on soybean and pumpkin seed meal supplementing diets. The bucks supplemented with pumpkin seed meal had the widest scrotal circumference (P < 0.05) of all the treatments studied. The bucks fed a supplementing diet containing pumpkin seed meal had higher semen pH (P < 0.05) than bucks on sole grazing group and soybean supplementing diet. Bucks on pumpkin seed supplementing diet had the greatest scores (P < 0.05) on total sperm motility and progressive motility; and sperm concentration followed by the bucks on soybean and the bucks on grazing only had the lowest score. The whole pumpkin seed meal could be used to improve productive performance and semen quality characteristics of free-ranging bucks.

Pasture research led by the International Center for Tropical Agriculture (CIAT) and national institutions during the 80's and 90's, contributed with new Brachiaria species with various characteristics and uses that were incorporated with success in livestock production systems in the lowlands of Latin America. Brachiaria brizantha, Brachiaria dictyoneura, Brachiaria humidicola and Brachiaria ruziziensis are some of the forage materials released by research institutions in the region. Despite its indisputable advantages, the Brachiaria genus presents limitations because of its low tolerance to prolonged droughts and its high susceptibility to spittlebug, a pest that causes considerable economic losses to the livestock industry. Thus, most recent research in CIAT's Brachiaria breeding program has focused on the development of a second generation of Brachiaria grasses: outstanding agronomic characteristics, establishment vigor, good sprout capacity, high biomass production and nutritional quality, good seed production, resistant to Rhizotocnia and to multiple spittlebug species. The results of this effort have conveyed to the recent release of Mulato grass, the first hybrid of the Brachiaria genus obtained by CIAT's genetic improvement program. In the waiting list of the second generation of Brachiaria grasses is hybrid #4624 (CIAT 36087), to be released in 2005, having a similar forage quality as Mulato and with all the attributes defined for the second generation of Brachiaria grasses. Moreover, several other hybrids are in advanced stages of evaluation and close to being released as commercial cultivars. The potential economic impact of the adoption of new Brachiaria hybrids on livestock production systems was evaluated using the Economic Model MODEXC. Two regions were considered in Colombia: the Northern Coast and the Eastern Plains. In Mexico, the tropical region; and in Central America, its six constituent countries. The model estimates the economic benefits attributable to the utilization of the new materials, disaggregating per country, region, ecosystem, production system and large social groups (consumers and producers). It works with two types of parameters: the technical ones that characterize the new technology and its process of dissemination, and the economic ones representing the conditions of market supply and demand of both beef and milk affected by the technical change. The benefits of the new technology (from the year 2007) were calculated for a period of 20 years and the results were expressed in terms of the net present value (NPV) and annuities. The estimates were made using alternatively an economic framework of open and closed economy. In a closed economy, without international trade, the NPV of the technological benefits was estimated at US$4,166 million, of which 54% would be generated by the marketing of beef and the rest by milk. Most of the benefits were concentrated in Mexico, US$2,831 (68%); followed by Colombia, US$960 million (23%), and Central America, US$363 million (9%). In order to have criteria on the extent of the estimated technological benefits, the value of beef and milk yield during 2003 was calculated in the reference countries. The NPV is equivalent to 44% of the value of that year, ranging between 16% in Honduras and 78% in Nicaragua. The results show the importance of the dual purpose livestock production system. In most countries, more than half of the technological benefits was generated in this system: Colombia 70%, Central America 62%, and Mexico 50%. When a country is self-sufficient and the surplus resulting from the technical improvements is marketed domestically, the benefits are transferred to consumers who are favored with the reduction in prices, making possible for them to increase consumption. In the case of a closed economy, consumers would capture 83% of total benefits. Trade liberalization implies a re-distributive process favoring producers. Export purchases increase total demand and restrain the fall of domestic prices. In an open-market economy, the share of benefits to producers would rise to 46%. Research investment is conceived as a primary mechanism to achieve two of the most basic social goals: 1) poverty reduction and improvement in equity, and 2) the promotion of economic growth. Having this premise, in order to establish to what extent this technical change contributes to the fulfillment of these goals, the acquired benefits were estimated for the most vulnerable population groups: a) The two quintiles of poor consumers, representing 40% of total population, and b) the small producers. In both schemes, open or closed economy, both groups receive more than one-fourth of the benefits from technical change, 27% and 31%, respectively. This is equivalent to a NPV ranging between US$1,137 to 1,303 millions. Because the hybrids require better soils or fertilizer inputs to maintain forage biomass productivity and quality, the study was made with conservative hypotheses about changes in productivity and the size of the area to be planted. Despite the definition of the levels of critical variables, especially those associated with the productivity and the adoption of the new Brachiaria hybrids, conservative criteria were considered in order to avoid overestimating the benefits; it is important to evaluate the sensitivity of these, against undesirable changes of those variables. For this purpose, three alternative scenarios were established: 1) The reduction of 50% of the area cultivated with new Brachiaria hybrids, 2) the reduction of 10% in the yields of the new materials, and 3) the increase of 50% in the total time of adoption. The most critical variable in the determination of the amount of benefits is yield (productivity) of the new technology, in terms of beef and milk per hectare. The elasticity of the benefits regarding the yields was estimated at 2.2 for Colombia and 1.8 for Central America and Mexico. This suggests that if the yield declines by 1%, the reduction of the social benefits is more than proportional. The social benefits are less elastic with regard to the area planted with new Brachiaria hybrids or the time of adoption. For example, in Colombia, if the area with improved materials declines by one percentage point, the benefits will diminish at approximately six tenths of one point. In all the proposed alternative scenarios, the investment in the development of these new pastures are economically attractive, despite the adverse circumstances proposed in these scenarios. The technological benefits expressed as an annuity (a fixed annual payment received for a specific number of years) shows that the investment for the development of new forage options is very low, less than US$ 20 million, compared with the annual benefits resulting from the use of these new materials.

The objective was to perform an ex-ante economic evaluation of new, legume-based forage alternatives available to farmers in Latin American tropical lowlands. These alternatives included grasses of the Brachiaria genus and the legumes Stylosanthes guianensis, Cratylia argentea, and Arachis pintoi. Case studies, involving farmers participating in the CIAT-led Tropileche Consortia convened by ILRI, were conducted in the forest margins of Pucallpa (Peru) and in the hillsides of the dry tropics of Esparza (Costa Rica) and Esquipulas (Nicaragua). A linear programming farm model developed by CIAT to maximize income was used for this analysis. Animal management parameters were based on farm averages at each reference site evaluated so that they represented current management conditions. Similarly, the model incorporated the prices of inputs and products typical of each country. A constant herd size was assumed for all alternatives evaluated. Production costs per kilogram of milk were estimated as the maximum expression of competitiveness, using three cow productivity parameters: the current average production per lactation (800 kg in Peru, 1,000 kg in Nicaragua, and 1,350 kg in Costa Rica); and two postulated parameters: 1,500 kg/lactation and 2,000 kg/lactation. For all forage options, key factors analyzed were (1) milk production costs resulting from implementing each forage alternative; (2) the investment required to establish each option, assuming the same number of milking cows and herd fertility; (3) the feasibility of obtaining credit with a local bank to invest in a forage alternative; and (4) the percentage of pasture area on the farm freed for other uses as a result of establishing one of the forage alternatives. Results indicated that the forage alternatives evaluated significantly improved the competitiveness of dual purpose farms in the hillsides of Nicaragua and Costa Rica, reducing the cost of producing milk between 13% and 37% with increased stocking rates, releasing up to 36% of area allocated to pastures. However, under current commercial banking conditions (real interest rates of 13% in Costa Rica and 18% in Nicaragua with payback periods of 5 years), the implementation of the options evaluated were not financially viable except for the establishment of Cratyla with sugarcane for dry-season feeding and Stylosanthes for pre-weaned calves. For all options to be implemented with commercial credit, a longer payback period was needed (8-10 years) and lower real interest rates (5-10%). The case of the forest margins of Pucallpa, was different, as none of the forage options evaluated, except Stylosanthes for pre-weaned calves, improved the competitiveness of farms under current management and production conditions due to low milk yields per cow and low proportion of herd in milk, which increased depreciation cost/cow to levels which were not viable. In addition, Pucallpa has an excess supply of forage biomass from a reduced herd inventory during the 80s and a limited fresh milk market which makes adoption of improved forages low attractive by farmers.

The present study was conducted to investigate the effect of fruits maturity stages at harvest on chemical composition, in vitro digestibility and in sacco degradability of Ficus surfruits (FSF). The treatments involved different maturity stages of Ficus sur fruits . Color, moisture content, and texture were used to distinguish among the fruit maturity stages. Fruits at early, mid, and late stages of maturity were collected from five trees and analyzed. The proximate composition of the fruits varied only slightly (0 to 3%) with the progress in maturity of the fruits. The exception was the DM content which increased from 45 to 87% with increasing maturity. The condensed tannins were low (<2%) for all the stages of maturity. In vitro and in sacco measurements indicated that the fruits at all stages of maturity were theoretically only slightly inferior to cereal grains as sources of digestible energy. However, the high washing loss in the in sacco study (38 to 42%) indicates that much of the digestible carbohydrate was in the form of soluble sugars which, depending on the levels used in the diet, could compromise the realizable net energy value of the diet. As in cereal grains, the crude protein content was relatively low (7.07 to 7.33% in DM).

High economic losses in agriculture can be caused by pig disease like Postweaning Multisystemic Wasting Syndrome (PMWS). Porcine circovirus-2 (PCV2) is the primary agent of PMWS. It is known that PMWS causes cellular and humoral immunity disorders, therefore it is considered a general immune deficiency disease in piglets. It is still unknown, why piglets with PMWS have severe loss of lymphocytes in lymphoid tissues and in the blood. Thus, the hypothesis of the study was that lymphocyte depletion occurs because of lymphocyte life-cycle delay in pigs infected by PCV2. The activity of cell life-cycle is attributed to protein Ki67. This protein is found in all active phases of the cell like interphase G1, S, G2 and mitoses. However, protein Ki67 is not observed at all in the cell’s “quiet” phase G0. The aim of our work was to investigate the lymph node cell proliferation activity of pigs infected by PCV2. In total, 42 pig carcasses were collected from 5 to 15 weeks old pigs with PMWS clinical manifestation. Lymph nodes were selected from each pig carcass for histological and immunohistochemical testing. We concluded that B lymphocyte population was reduced first in the lymph node with PCV2, but the number of T lymphocytes decreased later. PCV2 decreased B lymphocyte proliferation activity.

The aim of this study was to investigate the patterns of antibiotic resistance of Aeromonas spp. bacteria isolated from the sea trout (Salmo trutta) from the state fish hatcheries of the Institute of Food Safety, Animal Health and Environment ‘BIOR’, Latvia. Bacteriological investigations were performed at four state fish hatcheries located in the drainage basins of the main Latvian rivers – Daugava, Venta and Gauja, during the five-year period (2012 – 2016). In fish with visible clinical signs, bacteriological samples were collected from heart, liver, spleen, kidney and ulcer surfaces. Aeromonas hydrophila and Aeromonas salmonicida were isolated from sea trouts. A total of 52 individual sea trouts were examined. Resistance to amoxicillin, ampicillin, cephalexin, colistin, doxycycline, enrofloxacin, erythromycin, florfenicol, gentamycin, kanamycin, lincomycin, neomycin, oxytetracycline, spectinomycin, streptomycin, tetracycline, trimethoprim/sulfamethoxazole was tested. The results of this study suggest a multi-drug resistance pattern among the A. hydrophila isolates. All the isolates were resistant to amoxicillin (100%), ampicillin (100%), cephalexin (100%) and erythromycin (100%). The lowest level of resistance was found against florfenicol (4.55%), gentamycin (4.55%), kanamycin (4.55%), but susceptibility was recorded to enrofloxacin, neomycin and trimethoprim/sulfamethoxazole. A. salmonicida isolates were resistant to oxytetracycline (9.38%) and tetracycline (9.38%). For other antibiotics A. salmonicida isolates were susceptible.

Renewable energy resources have been developing very fast due to negative effects and finite reserves of the fossil fuels. Biomass is ranked among the most promising renewable energy resources within the Central Europe. Corn (Zea mays L.) is currently the most widely grown crop in the Czech Republic; nevertheless, the cultivation of corn provokes soil erosion by water. Perennial energy grass called tall wheatgrass (Elymus elongatus subsp. Ponticus cv. Szarvasi-1) is supposed to be a good and environment-friendly alternative to corn. Field trials including these two crops were established in the experimental locality of South Bohemia. Their yield potential was monitored during spring harvest periods (use for combustion). Dry phytomass was fundamentally analysed (N, C, H, S) and higher heating value was determined too. Universal Soil Loss Equation was calculated for both crop species. Corn provided much higher average yield in a three-year interval; corn phytomass reached higher heating value as well. The area of Elymus elongatus should enlarge considerably, if we wanted to get the identical amount of energy from corn and Elymus elongatus. However, we found that, compared to Zea mays L., water erosion theoretical land losses would be several times less serious for Elymus elongatus.