Influence of pasture feed chemical composition on growth performance of Latvian darkhead lambs

K. Griķe*, D. Kairiša and D. Bārzdiņa

Latvia University of Life Sciences and Technology, Faculty of Agriculture and Food Technology, Department of Animal Sciences, Lielā iela 2, LV-3001, Jelgava, Latvija
*Correspondence: kristiana.grike@gmail.com

Abstract:

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.

Key words:

average daily gain, feed chemical composition, lamb fattening, Latvian darkhead sheep breed, pasture

Effect of concentrate feeding technology on nutrient digestibility in Latvian Dark-Head lambs

L. Šenfelde, D. Kairiša and D. Bārzdiņa

Latvia University of Life Sciences and Technologies, Faculty of Agriculture, Institute of
Animal Science, Street Liela 2, LV-3001 Jelgava, Latvia

Abstract:

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.

Key words: