Sirvi Autor "Kairiša, D." järgi
Nüüd näidatakse 1 - 5 5
Tulemused lehekülje kohta
Sorteerimisvalikud
Kirje Analysis of scrapie resistance and productivity of Latvian dark head breed old type sheep compliant to the conservation program of the genetic resources(Estonian University of Life Sciences, 2023) Bārzdiņa, D.; Kairiša, D.Since 2002, the European Union has implemented a disease surveillance programme for transmissible spongiform encephalopathy (TSE) in small ruminants, which can cause very high economic losses to sheep farmers worldwide. In order to detect susceptibility to this fatal sheep disease, surveillance of this disease has been carried out in Europe for several years. Such a programme was introduced in Latvia in 2004 when the country joined the European Union, so Latvia has been monitoring this potential disease for several years. As this fatal disease has not been detected in Latvia, only a few studies have been conducted on scrapie genotypes in the Latvian Dark Head sheep breed and their effect on sheep productivity traits. The aim of the study was to analyse the productivity of the first lambs of Latvian Dark Head sheep in relation to the scrapie genotype. According to the data analysis, a total of 1531 or 97.7% of the ewes with R1, R2 and R3 scrapie genotypes can be used for future sheep breeding. The average age of all ewes included in the Programme was 5 years and the average fertility was 1.8 lambs. Later in the work, 1,335 Latvian Dark Head ewes with 100% bloodiness were analysed and the average fertility of ewes in the R1 and R3 scrapie genotype groups was 1.6 lambs and 1.7 lambs for ewes in the R2 risk group. In the last 10 years, the implementation of the conservation programme of the old type Latvian Dark Head sheep breed has been successful.Kirje Effect of Automatic Feeding Station use on fattening performance in lambs and intake activity periods(2018) Šenfelde, L.; Kairiša, D.Implementation of precise farming technology is v ery important for productivity increasing of livestock. One of the highest components of the production costs is feeding expenses. An automatic concentrate feeding stations (AFS) can ensure economic feed distribution and intake registration for animals ind ividually. The aim of this research was to study the possibility and benefits of using AFS in fattening of lambs. Results show that during all the research average number of daily visits to AFS per lamb were 13 ± 0.2 visits, average daily live weight gain per lamb was 254 ± 15.7 g. For 1 kg lamb live weight gain 5.35 kg concentrate was used. More intesively acitivity periods of lambs was noted during following hours of day time: 02:00 – 02:59 , 08:00 – 09:59 and 19:00 – 20:59. Significant ( P ≤ 0.05) moderate positive correlation (r = 0.470) was found between average daily number of visits to the AFS per lamb and total amount of concentrate consumed during the research per lamb. Significant ( P ≤ 0.05) strong negative correlation (r = - 0.806) was found between a verage daily number of visits to the AFS per lamb and average amount of concentrate consumed during one visit.Kirje Effect of concentrate feeding technology on nutrient digestibility in Latvian Dark-Head lambs(2020) Šenfelde, L.; Kairiša, D.; Bārzdiņa, D.Research has been conducted to evaluate the effect of concentrate feeding technology on nutrient digestibility in Latvian Dark-Head lambs. Twenty-four purebred Latvian Dark-Head lambs (rams) were divided into three study groups (four lambs in each group). Concentrate was offered with different feeding technologies: group 1 – ad libitum once per day (ADL); group 2 – five times per day (5TD); group 3 – three times per day (3TD). Lamb live weight at the start of research was 24.6 kg (ADL), 24.1 kg (5TD) and 25.6 kg (3TD), the average age – 83 ± 1.4 days (ADL; p < 0.05), 75 ± 1.4 days (5TD) and 75 ± 1.6 days (3TD). Research data were collected over three periods and two repetitions during lamb fattening in July, August and September, 2019. During the data collection period lambs were transferred to cages with slatted wooden floor and a container with a grid under it. The highest concentrate intake in all data collection periods was found in ADL lambs (1.25 ± 0.106 kg – 1.75 ± 0.092 kg on average per lamb). Hay intake was not equal (90–350 g in average per lamb).The highest average faecal production was found in 3TD and 5TD lambs (F – 0.98 ± 0.102 kg (3TD), S – 1.13 ± 0.060 kg (5TD) and T – 0.99 ± 0.070 kg (5TD)).The least urinal production was found in 3TD lambs (0.24 ± 0.038 kg (F), 0.61 ± 0.078 kg (S) and 0.47 ± 0.033 kg (T)). Dry matter digestibility was 66.54–80.39%. Faecal consistency was soft for ADL and 5TD lambs and solid for 3TD lambs.Kirje Influence of pasture feed chemical composition on growth performance of Latvian darkhead lambs(Estonian University of Life Sciences, 2025) Griķe, K.; Kairiša, D.; Bārzdiņa, D.Lamb fattening on pasture feed is widely used in the world and in Latvia as most of Latvian darkhead (LT) breed lambs are grazed on pasture with some addition of hay and straw. Clarifying the variable pasture grass chemical composition during the grazing season and comparing with growth performance of lambs can enable farmers to predict the fattening pace. The experiment was conducted during grazing seasons of year 2020 and 2021 at the ram breeding station owned by the Latvian Sheep hearder association. Pasture of 60% grasses and up to 20% of legumes and other broadleaf low grasses is recultivated every 4 to 5 years, grass is cut once a year, grazing is organized in rotational system of fenced paddocks where animals are moved periodically to ensure better feed quality as well as letting the previous paddock regrow. Total of 24 male LT breed lambs were used in the experiment. Pasture feed chemical composition was analysed from 13 samples in year 2020 and 9 samples in year 2021. The authors analysed pasture feed samples for nutritional content (dry matter - 27.1%, within a kg of dry matter protein - 12.5%, fiber - 26.2%, metabolizable energy - 10.8, etc.) and measured lamb growth parameters (average daily gain - 256.4 g d-1, fattening duration - 78.6 days, end liveweight - 45.1 kg). The research demonstrates that pasture feed quality varies significantly between years and affects lamb growth performance, with lower feed quality prolonging fattening duration. Despite this variation, the authors conclude that pasture grass feed utilization for lamb growth performance was optimal, with lambs reaching target weights within acceptable timeframes. Practical conclusion of this research is that by using rotational grazing system lambs can be fattened to reach target liveweight, even with lower pasture grass feed quality due to weather conditions and fattening period takes longer, the target weight is sufficient. Utilitarian suggestion is to organize lamb weaning and begin the fattening period as early in the season as possible to avoid the decreased grass quality in autumn.Kirje Meat chemical composition of pasture pure lambs and crossbreeds(2018) Vecvagars, J.; Bārzdiņa, D.; Kairiša, D.Increased customer interest of safe, healthy and environmentally friendly food consumption promote development of sheep farming industry in Latvia. Aim of the paper – explain of different pasture - fattened sheep breed and their crosses lamb meat composition traits. A study of pasture fattened lamb meat chemical composition was carried out from year 2013 to 2017. Fattening lambs were kept in breeding rams control station ‘Klimpas’ (57°50’58.8’’N 25°19’39.6’’E) pasture array. Lambs were slaughtered in a certif ied slaughterhouse, but analysis of meat chemical composition were conducted in laboratory of Institute of Food Safety, Animal Health and Environment (BIOR). For the analysis of the meat chemical composition were used up to 1 kg heavy Quadriceps femoris mu scle samples. In meat were analysed following elements of its chemical composition: dry matter, protein, fat, minerals, pH, cholesterol and unsaturated fatty acids. Data analysis shows that the lambs before slaughter ranged in age from 5 to 8 months. Lamb meat obtained from the study groups had a significantly different total amount of dry matter and fat. The lowest total fat, but the highest ash content was obtained in the lamb meat of the extensive breed group. The lowest total fat and the highest ash con tent were obtained in the lamb meat from the extensive breed group. In meat obtained a small (in individual samples < 0.10%) cis - 10 - pentadecenoic acid, cis - 11 - eicosenoic acid and myristoleic acid content. Of unsaturated fatty acids in lamb meat were represented higher amount of oleic acid, linoleic acid and elaidic acid.