Category Archives: Journal of Animal Physiology and Animal Nutrition

Effect of Brazilian spinach (Alternanthera sissoo) pellet supplementation and dietary ratios on rumen characteristics, microorganisms, methane production, milk yield, and milk composition in dairy cows

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Abstract

The aim of the previous research was to evaluate the effects of Brazilian spinach pellet (BSP) supplementation and dietary ratios on rumen characteristics, methane estimation, and milk production in dairy cows. Four crossbred Thai dairy cattle, with Holstein Friesian (HF) cows with a body weight of 442 ± 50 kg were assessed in a 2 × 2 factorial in a 4 × 4 Latin square design to obtain diets; factor A was the roughage (R) to concentrate (C) ratio at 40:60 and 30:70, and factor B was level of BSP supplantation at 2% and 6% of dry matter (basis) intake (DMI). R:C ratio and supplementation of BSP had no interaction effect on DMI and nutrient digestibility. On DM, organic matter (OM), crude protein (CP), and acid detergent fiber (ADF) intake, the R:C ratio increased (p < 0.05). The digestibility of OM improved (p < 0.05) when cows were fed a R:C ratio of 30:70. On pH, ammonia-nitrogen, protozoal population, and blood urea-nitrogen, there were no interactions between the R:C ratio and BSP supplementation. Increasing the BSP supplementation to 6% (p < 0.01) decreased the protozoal population. The R:C ratio of 30:70 increased total volatile fatty acid (VFA) and propionate (C3) concentrations while decreasing the acetate (C2) to C3 ratio and methane (CH4) estimation (p < 0.01). The average concentration of total VFA has increased by 114.46 mmol/L for 6% of BSP supplementation. Increased BSP supplementation increased the C3 concentration while decreasing the C2:C3 ratio and CH4 emissions (p < 0.05). The R:C ratio and BSP supplementation had no interaction effect on milk yield, 3.5% fat-corrected milk (FCM), or milk composition. The R:C ratio of 30:70 increased milk yield (p < 0.05) to the highest level of 12.18 kg/day. In conclusion, the diet containing a R:C ratio of 30:70 increased feed intake, milk yield, BUN, total VFA, and C3 concentration, and decreased the C2:C3 ratio and CH4 emission. BSP supplementation at 6% could increase TVFA and C3 concentrations while decreasing the protozoal population and CH4 estimation.

The quality of beef in the conditions of the former Semipalatinsk Test Site

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Abstract

The territory of the Semipalatinsk Nuclear Test Site represents vast areas of grassy steppes, their use as pastures seems promising. The purpose of work was to compare beef samples obtained from settlements belonging to different categories of radiation risk: Kokpekty village, Chagan urban-type settlement, Krivinka village, Sarzhal village, three samples were examined from each settlement. Organoleptic analysis, radiometric determination of 137Cs, was used as criteria. Also, an analysis of the amino acid composition by the high-performance liquid chromatograph method was carried out and a calculation of protein indicators was made: meat tenderness, amino acid usefulness, nutrition value. The organoleptic examination showed the compliance of all samples with the standards, with the exception of one sample from the Sarzhal village. The study of the specific activity of 137Cs showed a direct correlation between the category of radiation risk and the content of this radioisotope in meat from different zones. The availability of some deviations in the samples indicators obtained from the Sarzhal village indicates the need to approach the products control from this zone more carefully, and radioisotope analysis should become a decisive criterion in determining the safety profile of the product.

mTORC2‐AKT‐LAT1 signalling participates in methionine‐induced β‐CASEIN expression in mammary epithelial cells of dairy cows

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Abstract

This study investigated the role of the mammalian target of rapamycin complex 2 (mTORC2)-protein kinase B (AKT) signalling in methionine (Met)-induced L-type amino acid transporter 1 (LAT1) expression and milk protein production. Primary mammary epithelial cells (MECs) from mammary parenchymal tissues of three lactating cows and MAC-T bovine MECs were cultured with or without 0.6 mM Met. Rapamycin-insensitive companion of mTOR (RICTOR) siRNA, the mTORC1 inhibitor rapamycin and the AKT activator SC79 were used to evaluate the effects of mTORC2-AKT signalling on Met-induced LAT1 expression and function. Each experiment was performed three times. Data were analysed with a two-sided unpaired t test or ANOVA with the Bonferroni multiple-comparison test. Western blotting showed that Met stimulation increased RICTOR expression (~244.67%; p < 0.05; control, 0.15 ± 0.026; Met, 0.517 ± 0.109) and AKT-S473 levels (~281.42%; p < 0.01; control, 0.253 ± 0.067; Met, 0.965 ± 0.019) in both primary MECs and MAC-T cells. Rapamycin-induced mTORC1 signalling inhibition decreased only Met-induced β-CASEIN expression by ~21.24% (p < 0.01; Met, 0.777 ± 0.01; Met and rapamycin, 0.612 ± 0.04) and did not affect Met-stimulated AKT-S473 levels, suggesting that mTORC2-AKT activation upon Met stimulation also contributes to milk protein synthesis. LAT1 participates in Met-induced β-CASEIN expression. In dairy cow MECs, mTORC2 inhibition by RICTOR siRNA decreased LAT1 levels on the plasma membrane by ~45.13% (p < 0.01; control, 0.359 ± 0.006; siRICTOR, 0.197 ± 0.004). However, SC79-induced AKT activation had the opposite effect (p < 0.01). In primary MECs and MAC-T cells, Met stimulation increased cytosolic and plasma membrane LAT1 expression respectively (MECs, 113.98% and 58.43%; MAC-T, 165.85% and 396.39%; p < 0.05). However, RICTOR siRNA significantly reduced Met-induced plasma membrane LAT1 expression (~76.48%; Met, 0.539 ± 0.05; Met and siRICTOR, 0.127 ± 0.012; p < 0.05). Thus, Met increased LAT1 expression and function via mTORC2-AKT signalling, upregulating milk protein synthesis in dairy cow MECs.

In vitro aflatoxins recovery after changing buffer or protozoa concentrations in the rumen fermentation fluid

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Abstract

This study simulates in vitro the effects of (i) rumen acidity and (ii) change in rumen protozoa numbers on the recovery of aflatoxins (AFs). Two 24-h fermentation experiments were carried out using the same batch in vitro fermentation systems and substrate (dried corn meal) containing 11.42, 2.42, 7.65 and 1.70 µg/kg of AFB1, AFB2, AFG1 and AFG2 respectively. In Experiment 1, two buffer concentrations (normal salts dosage or lowered to 25%) were tested. Buffer reduction decreased gas production (730 vs. 1101 mL, p < 0.05), volatile fatty acids (VFA) and NH3 concentrations in the fermentation liquid (39.8 vs. 46.3 mmol/L, and 31.7 vs. 46.5 mg/dL respectively, p < 0.01). Recovery of all four AFs types was higher (p < 0.01) in the reduced buffer fermentation fluid, both as a percentage of total AF incubated (73.6% vs. 62.5%, 45.9% vs. 38.1%, 33.6% vs. 17.9% and 18.9% vs. 6.24% for AFB1, AFB2, AFG1 and AFG2 respectively) and as amounts relative to VFA production (163.4 vs. 123.5, 22.1 vs. 15.7, 48.8 vs. 22.5 and 6.16 vs. 1.86 ng/100 mmol of VFA, for AFB1, AFB2, AFG1 and AFG2 respectively). In Experiment 2, Stevia rebaudiana Bertoni extracts (S) or a Camphor essential oil (Cam) were added to fermenters and compared to the control (no additives, C). S and Cam addition resulted in a 25% reduction (p < 0.05) and a 15% increase (p < 0.05) in protozoa counts respectively, when compared to C. Both plant additives slightly reduced (p < 0.05) AFB1 recovery as a percentage of total AFB1 incubated (68.5% and 67.7% vs. 74.9% for S, Cam and C respectively). Recoveries of all other AFs were unaffected by the additives. In conclusion, the rumen in vitro AFB1 recovery (63%–75%) was higher than other AFs (3%–46%) and the acidic fermentation environment increased it. In our conditions, changes in protozoa numbers did not affect AFs recovery.