GI Ekologijos skyrius (14.04)

This study evaluated the effects of dietary linseed cake on the fatty acid profile of meat and abdominal fat, and on growth performance in broiler chickens. A total of 198 birds were randomly allocated to three groups (66 birds/group). The control group (C) received a standard soybean meal-based feed, while the LIN6 and LIN12 groups were fed diets that were supplemented with 6% and 12% linseed cake, respectively. Linseed cake supplementation reduced saturated and monounsaturated fatty acids, increased n-3 polyunsaturated fatty acids (PUFAs) in meat and abdominal fat, and lowered the n-6/n-3 PUFA ratio (FDR-adjusted p < 0.05). The 12% inclusion resulted in a more pronounced accumulation of n-3 PUFAs—4.3–5.0 times higher than the control—while 6% inclusion increased n-3 PUFAs by 2.8–3.3 times (FDR-adjusted p < 0.05). However, 12% inclusion negatively affected growth performance, reducing body weight by 9.9% and feed intake by 10.4% at 42 days (p < 0.05), whereas the 6% inclusion had no adverse impact (p < 0.05). These results indicate that 6% linseed cake represents the optimal practical inclusion level, effectively enhancing the n-3 PUFA profile of broiler meat and abdominal fat without compromising growth, while higher inclusion levels may impair production performance.

Objectives: The transition period is defined by significant physiological and behavioural changes in dairy cows, which can affect enteric methane emissions. While rumination duration is often used as an indicator of health and welfare, its association with methane emissions is inconsistent across various studies. This study was aimed at exploring if categorising cows based on average daily rumination time could uncover significant variations in methane emissions and to determine particular ingestive and activity behaviours linked to methane output. Furthermore, we applied Principal Component Analysis (PCA) to condense complex behavioural data into comprehensible patterns associated with methane production. This study aims to elucidate behavioural predictors of methane through the integration of classification and multivariate analytics, thereby facilitating the formulation of precision-based emission mitigation strategies. Materials and Methods: Thirteen clinically healthy Holstein cows were observed from 40 days before parturition to 21 days after parturition. Feeding behaviours and rumination were continuously monitored using RumiWatch noseband sensors [Itin+Hoch GmbH, Switzerland]. Methane emissions were quantified twice daily utilising a laser methane detector [HESAI HS4000]. Cows were classified retrospectively into three categories based on average rumination time: low (<404 min/day), medium (404–500 min/day), and high (>500 min/day). Principal Component Analysis was conducted on behavioural data to identify components linked to methane emissions. Results: Methane emissions were highest in medium-rumination cows, followed by high and low groups; however, the differences were not statistically significant (p > 0.05). In cows with low rumination, methane exhibited a negative correlation with rumination chews (r = -0.52, p < 0.05). In cows showing high rumination, methane levels were inversely correlated with drinking gulps (r = -0.42, p < 0.05) and bolus count (r = -0.37, p < 0.05). The findings indicate that methane production is more closely associated with particular ingestive behaviours than with the duration of rumination itself. PCA identified six components that account for 79.97% of the overall behavioural variance. Component 5 exhibited a significant negative loading for methane (−0.62) and positive loadings for "Other Chews" and "Activity," suggesting that heightened non-rumination jaw movements and locomotor behaviour may forecast reduced methane emissions. Conclusions: Although average rumination time alone did not significantly account for methane variability, multivariate behavioural traits identified through PCA indicated crucial predictors of methane emissions. The integration of behavioural classification with sensor-based analytics may enhance targeted enteric methane mitigation strategies in dairy herds.

Addressing the challenge of mitigation GHG emissions from manure, we conducted a study to assess the effectiveness of various sorbents in reducing emissions of ammonia (NH₃), methane (CH₄), carbon dioxide (CO₂) from cattle manure during storage. Fresh liquid cattle manure was subjected to three treatments (30% sorbents): perlite (Group 1P), vermiculite (Group 2V), and superphosphate (Group 3S). The Control group (C) consisted of manure without any sorbents. The experiment was conducted under laboratory conditions utilizing 25-liter experimental tanks over a 37-day period. Gas emissions were quantified using passive chamber method. The results indicated that different sorbents could have very different effects on individual gas emissions, depending on the manure storage period. The most substantial reduction in emissions was observed for CH₄. At the beginning of the experiment, CH4 emissions were reduced by 90.2% (p≤0.005) in the 1P group, and by 77.2% (p≤0.05), in the group 3S compared to the C group. The reduction of NH₃ emissions was less pronounced, with superphosphate demonstrating the highest efficacy at the beginning of the experiment, achieving a 36.3% reduction (p≤0.05). However, by the end of the study, NH₃ emissions exhibited a slight increase (5–42.5%) compared to Group C, but the differences were insignificant. The lowest effectiveness was found with CO₂ gases. Results showed that perlite (1P) increased CO₂ emissions by 62.5% (p≤0.005) during the experiment. It can be concluded, that tested sorbents had different effects on various gases, which were influenced by the duration of manure storage.

The trial aimed to assess the effect of adding Camelina cake to the chicken diet to improve the muscle fatty acid profile while maintaining growth performance. The trial was conducted with 5% and 10% Camelina cake inclusion levels in the diet. A total of 210 one-day-old, sex-unrelated chickens were assigned to three dietary treatment groups. The control group received a diet consisting of wheat and soy meal, while the treatment groups had part of the soy meal replaced with 5% Camelina cake (CAM5) or 10% Camelina cake (CAM10). The results indicated that Camelina cake positively affected the production of healthier breast and thigh meat. Specifically, the levels of various Omega-3 fatty acids, which are considered beneficial for human health, were significantly higher in the treatment groups compared to the control group. The greatest increase was observed in α-linolenic, eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids, which increased by as much as 1.7 to 2.67 times (p ≤ 0.05) in both treated groups. Additionally, the total n-3 PUFA content increased by 2,36 – 3.36 times (P ≤ 0.05), while the n-6/n-3 PUFA ratio, TI index, and total trans fatty acids decreased. The inclusion of 10% Camelina cake had a greater effect on n-3 PUFA content compared to the 5% inclusion level. Analysis of the chickens’ growth showed that neither 5% nor 10% Camelina cake supplementation did not affected their growth performance. In summary, the inclusion of 10% Camelina cake in chicken feed can enhance the nutritional profile of the meat, particularly by increasing n-3 PUFA content, without negatively affecting the chickens’ growth.

This study investigates the relationship between methane emissions and physiological, behavioural, and haematological parameters in dairy cows during the transition period. Methane emissions were monitored alongside variations in rumination, feeding behaviour, and blood markers three weeks before calving, on calving day, and three weeks post-calving. Cows were retrospectively classified into low, medium, and high rumination groups according to their average daily rumination duration to investigate the effects of behavioural influences. During the prepartum period, the methane concentration was moderately positively correlated with drinking time (r = 0.41, p < 0.01) and weakly negatively correlated with chews per minute (r = −0.358, p < 0.05). Significant negative correlations were noted with chloride (r = −0.42, p < 0.01) and glucose levels (r = −0.41, p < 0.01). Following calving, methane emissions showed a positive correlation with haematocrit (r = 0.41, p < 0.01) and a negative correlation with haemoglobin (r = −0.47, p < 0.01). A haematological analysis revealed a notable negative correlation with platelets during calving (r = −0.64, p < 0.05). Individual dry matter intake (DMI) was recorded for each period, showing a significant drop on calving day. This intake fluctuation coincided with a significant rise in methane yield on calving day (p < 0.001). In the low rumination time group, methane was moderately negatively correlated with rumination chews (r = −0.52, p < 0.05), while in the high rumination group, a moderate negative correlation was observed with drinking gulps (r = −0.42, p < 0.05), and a weak negative correlation was observed with bolus events (r = −0.37, p < 0.05). Despite behavioural variations, methane emissions showed no substantial differences among groups with low, medium, and high rumination times, suggesting a minimal direct influence on rumination duration. These findings emphasise the complex interactions between feed intake, metabolism, and methane emissions, underscoring the importance of integrating behavioural and physiological indicators to develop targeted strategies for enteric methane mitigation while providing baseline data from healthy cows that could guide future research on methane emissions in cows undergoing postpartum metabolic disorders.

Pedigree completeness and genetic diversity are essential factors in evaluating the sustainability and breeding potential of livestock populations. This study investigates the genetic structure and pedigree completeness of Lithuanian Red (LR) and Lithuanian Black-and-White (LBW) cattle, focusing on both open and old genotype populations. The analysis utilized PopReport software and data from the Lithuanian Agricultural Data Center. The LR open population comprised 313214 animals, while the LBW open population included 354201. The old genotype LR population consisted of 1266 recorded animals, of which 77% were bred under a pure-breeding system. The old genotype LBW population contained 9058 animals, with 58% maintained through pure breeding. Pedigree completeness in the first generation was 100% across all populations, except for old genotype LR (93.8%). A progressive decline was observed in subsequent generations, with fourth- and fifth-generation completeness averaging 88.2% and 83.0%, respectively. The sixth generation exhibited the lowest completeness: 72.5% in old genotype LR and 69.3% in LBW populations. Age distribution analysis revealed that open populations comprised younger cows and heifers (3.3 years for LR, 3.2 years for LBW), suggesting higher reproductive potential. In contrast, old genotype populations exhibited older age averages (3.8 years for LR, 4.4 years for LBW), indicating reduced reproductive intensity. The reproductive age peaked in 2009 (7.3 years for LR, 5.3 years for LBW) but declined significantly by 2021 (3.3 and 3.7 years, respectively). Between 2005 and 2020, generation interval decreased by 3.6 years for males and 1.2 years for females in LR open populations, and by 3.1 years and 0.8 years, respectively, in LBW open populations. Conversely, between 2005 and 2015, the LR old genotype bull interval increased by 1.1 years, while in LBW old genotype populations, it declined by 4.6 years. The study emphasizes the importance of managing genetic diversity and optimizing breeding strategies to ensure sustainable cattle production in a changing agricultural environment.

Genetic selection of cows with lower methane emissions is a promising strategy for mitigating greenhouse gas emissions in livestock. However, understanding the relationship between methane emission traits and other phenotypic characteristics remains challenging. Therefore, this study aimed to assess and compare enteric methane emissions from Lithuanian local breeds (Ash-grey, White-Backed and old genotype Lithuanian Red) reared under extensive production conditions, with those from widely bred Holstein cows, which are kept under intensive production conditions. Individual methane emissions were recorded using a Laser Methane Detector (LMD). Based on a methane measurement protocol, including outlier analyses and physiological aspects, methane traits were determined reflecting respiration, eructation and average methane emissions were derived. The dataset comprised 754 records from 80 cows. Our findings showed that the average daily methane emissions from Lithuanian local breeds cows were 20.7% lower (p<0.01) than those from Holstein cows. Among local breeds, the highest methane emissions was determined from White-Backed cows, which were 9.3% higher than from old genotype Lithuanian Red and 13.6% higher than from Ash-grey cows. However, completely different results were obtained when calculating methane emissions per unit of production. The calculations revealed that Holsteins and old genotype Lithuanian Red cows emitted significantly less methane, amounting to 16.1±0.7 and 16.7±1.7 g of methane per kilogram of milk, respectively. While methane emissions from Ash-grey cows were 57.5 and 51.8% higher, from White-Backed cows were 60.1 and 54.4% higher, respectively. In summary, our results suggest that although enteric methane emissions from Lithuanian local breeds cows were lower, methane emissions per kilogram of milk were significantly higher compared to those from intensive breed cows.

Consumers prefer poultry for its high quality, nutritional value, and lower cost. With population and income growth, animal protein consumption is expected to rise. As populations age, health concerns increasingly influence purchasing decisions, and there is a growing demand for diverse protein sources and environmentally sustainable production. Quail meat is a promising alternative for this niche. The purpose of the study was to investigate the effects of dietary hempseed or camelina cakes on the fatty acid profiles of intramuscular fat in the muscles of quail. A total of 189 one-day-old quail were allocated to 3 dietary treatments. The diet of the Control (C) group was supplemented with 10% rapeseed cake, whereas the rapeseed in Experimental 1 (HE) and Experimental 2 (CA) groups was replaced by, respectively, hempseed cake and camelina cake in the same proportions. Dietary enrichment with camelina cake increased the ALA content in the meat of CA group 2.5 times (P < 0.01). The muscle tissues of CA contained 3.4–3 times more EPA (P < 0.01), 1.2 times more DPA (P < 0.05–P < 0.01) and 1.3 times more DHA (P < 0.01) and, thus, demonstrated the increase in total long chain (LC) n-3 PUFA (P < 0.01) and total n-3 PUFA (P < 0.01) compared with the C group. The decrease was observed in the amounts of LA, total n-6 PUFA, n-6/n-3 PUFA and LA/ALA ratios and TI index. The ALA and total n-3 PUFA content in the breast and leg meat of HE treated quail was respectively 1.3 and 1.1 times higher (P < 0.01) than in the C group, but the accumulation was lower compared to the CA group. The content of GLA was found to be 1.21–1.31 times higher in HE quails meat (P < 0.01). Supplementation of quail feed with camelina or hempseed cakes resulted in the production of healthy meat with an increased n-3 PUFA content. A wider employment of oil industry by-products in quail farming could contribute to higher production sustainability and reduce dependence on imported feed materials.

Ammonium (NH4+) content is one of the most important parameters in manure assessment. The accurate and rapid determination of this inorganic form of nitrogen is therefore important not only in agronomy, when calculating fertilizer application rates, but also in scientific studies, for example, in the study of greenhouse gas emissions from stored manure. There is not enough research to assess which analytical method is the most appropriate for the determination of (NH4+) in manure with additives such as perlite, vermiculite, or peat. We compared three analytical methods for NH4+ determination: distillation, ionometry, and spectrophotometry. The results showed that the distillation method had the lowest average coefficient of variation (Cv) between the two laboratory replicates, with a Cv = 0.77%, while the ionometry and spectrophotometry methods had average Cv values of 1.83% and 3.97%, respectively. A lower coefficient of variation indicates that the analytical method is less sensitive to various interferences, resulting in more reliable data. Experimental data also show that storing manure for 40 days reduces the NH4+ content from about 21,000 ppm to about 7000 ppm and that the use of additives such as perlite, vermiculite, or peat did not significantly affect NH4+ retention compared with control samples (without additives). Based on the results of our study, we recommend using the distillation method for the determination of NH4+ in the manure with additives in agrochemical and scientific laboratories.

The effective population size (Ne) is a key parameter in population genetics with significant applications in evolutionary biology, conservation genetics, and animal breeding. It provides insights into the rates of genetic drift and inbreeding, which in turn affect the efficacy of evolutionary forces such as mutation, selection, and migration [1–2]. The aim of this study was to investigate the effective population sizes between two open (commercial) populations, i.e., Lithuanian Red and Red-and-White (LRWP) and Lithuanian Black-and-White (LBWP), and two old genotype populations, i.e., Lithuanian Black-and-White (LBW) and Lithuanian Red cattle (LR), which currently are under conservation. The effective population size (Ne) is one of the most commonly used indicators of genetic diversity, and for animal breed conservation purposes, it can be defined in various ways [3–5]. Therefore, in our study the effective population size was calculated using four methods: based on the rate of inbreeding; based on the number of parents; based on the co-ancestry; and based on the regression on equivalent generations. The data on the Lithuanian dairy cattle populations were provided by the Centre for Agricultural Information and Rural Business. The input data consisted of the unique identification of all animals: animal ID, sire ID, dam ID, birthdate and sex. The research showeed that the lowest effective population size (Ne) concerning the rate of inbreeding was observed in LBW (23) and LRWP (68), with the highest Ne identified in the LBWP population (462). When considering Ne based on the number of parents, LR displayed the lowest Ne (107), while the highest Ne was found in LBWP (4449). At the end of 2021, the effective population size, based on the co-ancestry, was calculated for LRWP, LBWP, LR and LBW and was found to be 121, 58, 29 and 28, respectively. In 2017–2021, the effective population size based on the regression on equivalent generations decreased in all the breeds. The highest decrease (63%) was found in LR and the lowest (20%) in LBWP. This study demonstrates that current breeding strategies are leading to a significant reduction in genetic diversity in both commercial (open) and old genotype populations of Lithuanian dairy cattle. The effective population size (Ne), calculated using four different methods, revealed critical trends in genetic drift and inbreeding. The ongoing decline in Ne, especially in smaller, conserved populations, poses a serious threat to the sustainability of these breeds. Lower Ne values are closely linked to increased rates of inbreeding and reduced genetic adaptability, making populations more vulnerable to environmental changes and production pressures.