Keywords | Rumen degradability, Intestinal digestibility, Protein nutritive value, Sunflower meal

The aim of the present study was to evaluate the association between seasonal variation, the temperature–humidity index (THI), and lipid indices related to human health in the milk of Simmental and Montbéliarde cows. The investigation was conducted on a dairy farm located in Central Southern Bulgaria over a 12-month period and included 100 lactating cows, with equal numbers from each breed, housed in semi-open free-stall barns and fed an unchanged total mixed ration. Monthly measurements of microclimatic parameters (temperature, relative humidity, THI, and air velocity) were conducted throughout the study, and composite milk samples were analyzed for fatty acid composition by gas chromatography. The atherogenic index (AI), thrombogenic index (TI), health-promoting index (HPI), hypo-/hypercholesterolemic index (h/H), desaturase indices (DI16 and DI18), and the UFA/SFA, PUFA/SFA, and MUFA/SFA ratios were calculated based on the fatty acid profile. The results indicate that season has a statistically significant effect on all studied lipid indices (p < 0.001). The Kruskal–Wallis H values ranged from 16.68 for AI to 27.82 for DI18, indicating that seasonal variations in microclimatic conditions significantly influence the lipid metabolism of the cows. The data for the studied lipid indices indicate that the most favorable fat profile for human health was observed in autumn, characterized by lower AI (2.24) and TI (1.26) values and higher HPI (0.45) and h/H (0.76) values. Seasonal variation also affected DI 16 and DI 18, with the most favorable values for humans observed in autumn (DI 16: 4.38; DI 18: 74.39). The ratios of unsaturated to saturated fatty acids (UFA/SFA, PUFA/SFA, and MUFA/SFA) indicate that the milk from the studied farm exhibits the most favorable functional properties in autumn.

The present study aimed to investigate the effect of Turnera diffusa supplementation on the quantitative and qualitative characteristics of semen in Duroc boars (n = 4). The experiment was divided into two periods, each corresponding to the duration of one spermatogenic cycle: a control period (40 days) (CP) and an experimental period (40 days) (EP). Nutrition and environmental conditions were kept constant throughout both periods. During the experimental period, each boar received a daily supplement of 7 g of Turnera diffusa extract. In each period, five ejaculates were collected from each boar included in the study. The ejaculates were evaluated for volume, sperm concentration, motility, agglutination, number of insemination doses obtained per ejaculate after dilution, and sperm viability after 24, 48, and 72 h of storage. The results of a two-way repeated measures ANOVA showed that the combined effect of boar × treatment significantly influenced ejaculate volume (p < 0.01) and viability after 48 h of storage (p < 0.05). The results of the two-way repeated measures ANOVA showed that treatment with the tested additive T. diffusa significantly affected sperm survival during storage for 24 h (p < 0.01), 48 h (p < 0.001), and 72 h (p < 0.05). Bonferroni post hoc analysis indicated that T. diffusa significantly affected only the parameters related to sperm viability, namely survival rates at 24 h (p < 0.001), 48 h (p < 0.01), and 72 h (p < 0.01). The findings of this study demonstrate that the application of the tested supplement, at the specified dose and duration, has a positive effect on semen quality in boars.

The objective of this study was to evaluate rumen degradation kinetics and intestinal digestibility of low-protein fraction from sunflower meal (LPSFM). Three non-lactating Jersey cows with an average body weight of 436 ± 18 kg fitted with a rumen and T-type duodenal cannulas were used in the experiment. Five samples of LPSFM from different batches produced in 20-d intervals were collected and incubated in the rumen of the cows for 0, 2, 4, 8, 16, 24 and 48 h in 6 replicates. The average CP content of LPSFM was 175 (SD = 6.98) g/kg. Data were fitted to nonlinear regression model and analyzed statistically using SPSS. The soluble or rapidly degradable fraction а of LPSFM dry matter (DM) ranged from 105 to 137 (SD = 11.3) g/kg. The effective degradability of DM at assumed rumen outflow rate of 0.06/h ranged from 293 to 338 (SD= 16.3) g/kg. Fraction a of CP ranged from 124 to 189 (SD = 23.9) g/kg. Effective degradability of LPSFM CP at rumen outflow rate of 0.06/h ranged from 515 to 560 g/kg (SD = 16.2). Intestinal digestibility of LPSFM (after 16-h rumen incubation) DM and CP measured by the mobile bag technique varied from 318 to 349 g/kg (SD = 10.5) and from 766 to 820 g/kg (SD = 17.7), respectively. The average estimated Protein Digestible in the small Intestine (PDI) and Rumen Protein Balance (RPB) of the LPSFM samples analyzed in the current study, following equations in the Bulgarian feed evaluation system (at 0.06/h outflow rate), were 113 (SD = 1.67) g/kg and 125 (SD = 14.9) g/kg, respectively. The protein degradability and digestibility values obtained in this experiment can be effectively used in formulating rations for ruminant animals.

A study was conducted at “Farma Kapitanova” Ltd. using 4 boars with an average live weight of 288.5 ± 14 kg and an average age of 18.75 ± 1.75 months, belonging to a synthetic (terminal) Duroc line, over a period of 80 days. The experiment was divided into two sub-periods corresponding to the duration of one spermatogenetic cycle: a control period (40 days) – referred to in the study as Period 1, and an experimental period (40 days) – referred to as Period 2. The phytogenic supplement containing leaf extract of Turnera diffusa exerted a beneficial effect on ejaculate volume, sperm concentration, and the number of insemination doses obtained per ejaculate. The supplement significantly improved sperm survival during storage at 24, 48, and 72 hours, indicating its positive role in maintaining semen quality in boars.