ABSTRACT The aim of this experiment was to investigate the effects of dietary lipoic acid (LA) supplementation on meat quality and antioxidant regulation mechanisms in finishing pigs subjected to oxidative stress challenge induced by diquat (DQ). A 2 × 2 factorial design was applied using 24 Large White barrows (70.64 ± 3.61 kg; n = 6 per group) assigned to Control, LA (800 mg/kg LA), DQ (8 mg/kg BW) and DQ + LA treatments. DQ was administered intraperitoneally on day 15, and pigs were slaughtered on day 29 for collection of Longissimus dorsi samples. Carcass traits, meat quality traits (pH, colour, drip loss and shear force), Nrf2/Keap1 protein levels, myofiber-related genes expression (MyHC isoforms), and SOD activity and expression were analysed. We found that LA and DQ showed limited effects on carcass traits, except for a significant DQ × LA interaction on backfat thickness. DQ reduced pH24 h and increased L24 h, indicating accelerated post-mortem acidification and altered meat colour. LA increased a45 min and significantly affected shear force, with a pronounced interaction under oxidative stress. DQ markedly upregulated Nrf2 protein expression, while LA partially attenuated this increase without affecting Keap1. DQ and LA significantly modulated myofiber type-related genes, with stress-dependent interactions observed for MyHC I and MyHC IIb. Moreover, DQ enhanced SOD mRNA, protein expression and enzyme activity, whereas LA increased SOD mRNA expression independently of oxidative stress, with no significant interaction effects. In conclusion, dietary LA modulated antioxidant capacity and muscle fibre gene expression in finishing pigs challenged with DQ; However, its effects on meat quality were stress-dependent rather than uniformly beneficial, indicating that further studies are needed to clarify its role in maintaining overall pork quality under diquat-induced oxidative stress challenge.

ABSTRACT This study evaluated the effects of sorghum silages treated with chemical, microbial, and combined additives on fermentative quality, aerobic stability, nutritional composition, and productive performance of confined sheep. Forty uncastrated male sheep were used, distributed among four treatments: silage without additives (control); silage treated with a chemical additive based on organic acids; silage inoculated with Lentilactobacillus buchneri; and silage treated with the combination of both additives. The silages were evaluated after 90 days of storage, and the animals were confined for 60 days, receiving individually adjusted diets. The diets were provided as a total mixed ration composed of sorghum silage, ground corn, cottonseed cake, urea, mineral supplement, and ammonium sulphate, with the concentrate ingredients being mixed with the silage at the time of feeding. No significant differences in dry matter intake were observed among treatments. However, animals fed treated silages, especially with the combination of additives, showed greater intake of non-fibrous carbohydrates and metabolisable energy. The apparent digestibility of dry matter, organic matter, crude protein, and ether extract was higher with the use of additives, particularly in the combined treatment, which also presented the highest total digestible nutrient content. Daily weight gain was greater in sheep fed silages treated with both additives. Furthermore, the additives improved aerobic stability and reduced discard losses during the feeding period. Therefore, the application of chemical and microbial additives to sorghum silage promoted better nutrient preservation, fermentative profile, and aerobic stability, resulting in greater nutrient utilisation and improved productive performance in sheep.

ABSTRACT The nutrient composition of the pea grain fraction that escapes precaecal digestion may vary in response to the pea variant, affecting its fermentation characteristics in the hindgut. Quantifying the formation of fermentation end products in vivo remains challenging. Therefore, this study investigated the digestion and fermentation characteristics of 12 pea variants using two combined in vitro assays. In vitro indigestible solids (IVIS) of pea grains, representing the fraction of pea grains escaping precaecal digestion, were incubated for 48 h using a modified Hohenheim gas test with pig faeces as inoculum. Gas production was recorded at nine time points, and NH4 +-N and volatile fatty acids (VFA) were measured at 8 and 24 h. Precaecal disappearance was high for starch and crude protein ( >94%), whereas fibre fractions remained largely undigested ( <16%) and were the most abundant and variable fraction in the IVIS. Incubated IVIS differed in potential gas production and maximum rate of gas production among pea variants (p < 0.001, 46.7 to 73.9 mL/200 mg dry matter and 2.9 to 5.1 mL/h, respectively). For metabolite concentrations, an effect of the IVIS was observed for NH4 +-N and VFA at 8 and 24 h (p < 0.001). Multivariate regression showed a positive association of acid detergent fibre with the potential gas production (p < 0.001, R2 = 0.82). The concentration of crude protein was positively associated with the NH4 +-N concentration at 8 and 24 h (p < 0.001, R2 = 0.85, R2 = 0.86). The crude fibre concentration was negatively associated with the branched-chain fatty acid concentration at 24 h (p = 0.001, R2 = 0.70). Starch concentration was positively associated with gas production at 2 h (p < 0.016, R2 = 0.49) and propionate concentration at 8 h (p < 0.038, R2 = 0.86). To conclude, early-stage propionate production is driven by the precaecal indigestible starch, whereas the fermentation potential is primarily determined by the precaecal indigestible fibre fractions. Formation of metabolites by protein fermentation depends on the concentration of precaecal indigestible protein but may be inhibited with higher fibre concentrations. The differences in fermentation characteristics among IVIS of pea variants were associated with the analysed nutrient composition of the IVIS but not with those of the original grains.

ABSTRACT The objective of this study was to determine the effects of growing stage (GS) on morphological and chemical composition of whole-plant soybean (WPS), and fermentative profile and chemical composition of whole-plant soybean silage (SS). This study was divided into two trials conducted in a complete randomised block design. The first trial evaluated the effect of GS from R1 to R8 (59–135 d after sowing) on morphological and chemical composition of WPS and its botanical components. The second trial determined the effects of GS from R3 (71 d after sowing) to R7 (124 d after sowing) on dry matter (DM) losses, fermentative profile, chemical composition and aerobic stability of SS. The proportion of leaves in WPS was reduced, while stem and pod proportions were increased as the GS progressed. Ensiling WPS at R6 and R7 decreased the contents of acetic acid, lactic acid and branched-chain fatty acids, and ethanol, and increased the contents of propionic acid and NH3-N. However, silage butyric acid concentrations in R6 and R7 were relatively high (18.1 and 19.9 g/kg DM, respectively). Butyric acid and buffering capacity varied according to GS with the lowest values observed in silages derived from GS R3, R5 and R7, and the highest values observed in silages made from GS R5. Later GS resulted in greater contents of DM, crude protein and ether extract, and lower contents of acid detergent fibre and non-fibre carbohydrate in SS. The high fat of SS produced from later GS limits high inclusion levels in ruminant diets. Morphological components impacted chemical composition of SS, whereas the R7 stage improved fermentative profile and resulted in an SS with greater in situ degradability of DM and neutral detergent fibre.

ABSTRACT The reduction of nitrogen (N) and phosphorus (P) in fattening pigs’ diets is one possible approach to lower N and P excretion in livestock farming relative to N and P intake. Due to the implementation of the European Nitrates Directive and the consecutive amendments to the German fertiliser legislation since 2017, N- and P-reduced diets for fattening pigs are becoming more and more important and are increasingly used in practice. To investigate the effects of such diets on N and P balance and retention as well as on nutrient digestibility of contemporary fattening pigs, a balance experiment was performed with eight barrows (average live weight = 61.5 ± 2.1 kg) which were surgically fitted with a simple T-cannula at the terminal ileum. The pigs received a control diet meeting nutrient requirements (CON) and an N- and P-reduced diet (NPred) ad libitum (n = 4/diet) in a 3-phased feeding regimen (3 weeks/phase). In the last week of each phase, faeces and urine were collected quantitatively for 5 days followed by a 2 × 12 hours collection of ileal digesta. Daily feed intake, live weight gain and feed-to-gain ratio did not differ between CON and NPred. NPred-fed pigs consumed 10.5% (p = 0.006) and excreted 28.3% (p = 0.028) less N than CON-fed pigs. Phosphorus excretion was lowered by 15.1% in NPred-fed pigs (p = 0.012). N and P retention did not differ between CON and NPred, but were elevated in comparison to other studies. N and P efficiency, expressed as nutrient retention divided by nutrient intake, was higher in NPred – than CON-fed pigs (N: 68 vs 60%, P: 54.2 vs 49.3%). Apparent post-ileal digestibility coefficient (DCpost-ileal) and apparent total tract digestibility coefficient (DCtotal) of crude protein were higher in NPred – than CON-fed pigs (p < 0.013), but apparent precaecal digestibility coefficient (DCpc) of crude protein was unaffected by diet. DCpc, DCpost-ileal and DCtotal of P were similar for CON- and NPred-fed pigs. NPred-fed pigs showed an elevated DCpc and DCtotal of organic matter, N-free-extractives and starch compared to CON-fed pigs. DCpc of calcium was also higher in NPred-fed pigs. In conclusion, the results suggest that N- and P-reduced feeding of fattening pigs remains an effective strategy to lower the N and P release into the environment. Furthermore, results indicate that N- and P-reduced feeding leads to a higher N and P efficiency in contemporary fattening pigs.

ABSTRACTThe aim was to evaluate the animal response and the chemical and physical changes of free-choice mineral mixtures fed to grazing cattle. Growing beef cattle were fed either powder (POW) or agglomerated (AGL) mineral mixtures in three different experiments (Exp.), carried out in pastures of Brachiaria grass. In Exp. 1 and 2, the mineral mixtures were disposed in unsheltered troughs (POWun vs. AGLun), being delivered once (D0, Exp.1) or twice (D0 and D8, Exp. 2), throughout 14-day periods. In Exp. 3, POWun and AGLun were additionally compared to POW in sheltered troughs (POWshe), and the mineral mixtures were disposed in D0, throughout 21-day periods. Non-consumed supplement was removed and sampled on D14 (Exp. 1 and 2) or D21 (Exp. 3). Evaluations included average daily body weight gain (ADG), daily disappearance of the supplement (DSD), penetration force of the supplement mass, faecal chemical composition and serum levels of Ca, P and Mg. In Exp. 1, no effects were observed on ADG and faecal mineral concentrations, however, changes in mineral concentrations and a 40% reduction in Na concentration in the supplement were observed, compared to the initial concentration. AGLun had a lower penetration force. In Exp. 2, there were no effects on DSD and faecal mineral concentrations. POWun showed a smaller reduction in Na content compared to AGLun, and AGLun showed lower penetration force. In Exp. 3, the treatments did not affect ADG, but there was a trend towards higher DSD and serum phosphorus (P) concentration for AGLun (p = 0.08). Higher faecal Na concentration was observed for AGLun and higher Na concentration occurred in non-consumed mixture of POWshe. Mineral supplements offered in uncovered troughs showed altered chemical and physical characteristics, with possible effects on supplement intake. However, the general changes are unlikely to alter animal performance.

ABSTRACTDespite the increasing importance of goat production in response to high demand for their products and their relative robustness to environmental stressors, and in contrast to other ruminant species, little data is available on how tannin extract feeding affects their feed intake, nutrient digestion and nitrogen (N) metabolism. Therefore, a trial in Oman investigated the respective variables by using a commercial tannin feed additive. In a 4 (treatments) x 3 (periods) x 2 (animals) Youden square, two weaned Batinah bucks each were fed a high or low protein diet of Rhodes grass hay and crushed barley grain, with or without the addition of a chestnut and quebracho tannin extract at 2 g/kg metabolic weight. Feed offered, feed refused and faeces and urine excreted were quantified to determine diet digestibility, total N excretion, N retention and rumen microbial protein synthesis (MPS). Due to their young age and low live weight, feed intake of goats was relatively low. Crude protein level and tannin addition had no statistically significant effect on dry matter (DM) and N intake, DM digestibility, N excretion in faeces and urine, as well as MPS. In consequence, no benefit of tannin feeding could be confirmed for the goats’ N retention, irrespective of diet composition. These results indicate, on one hand, an effective neutralisation of the tested tannin extract along the gastrointestinal tract of goats, but on the other hand, that stimulation of MPS or N retention by tannins cannot be evidenced when diet components are present that simultaneously release energy and protein, as is the case with barley.

ABSTRACT Corn peptide (CP) is a small, natural, biologically active peptide obtained by protease-catalysed hydrolysis of corn. CP exerts antihypertensive, hypoglycaemic, antihyperlipidemic, antioxidant, and antitumor effects, as well as prevents cardiovascular and cerebrovascular diseases. Although CP plays a role in preventing obesity-related diseases, its role in reducing obesity has not yet been determined. In this study, we analysed the inhibitory effects of CP on lipid droplet accumulation in 3T3-L1 preadipocytes and high-fat diet (HFD)-induced C57BL/6J Obese Mice. The results show that CP could inhibit preadipocyte differentiation and oil accumulation in 3T3-L1 preadipocytes. Oral CP administration reduced serum triglyceride (TG) content, epididymal fat weight, abnormal liver fat droplet accumulation, and C/EBPα expression. Furthermore, combination of CP administration and exercise reduced body, liver, and adipose tissue weights; decreased serum total cholesterol (TC), triglyceride and low-density lipoprotein (LDL) levels; and inhibited hepatic lipid droplet accumulations and epididymal fat cell hypertrophy. Additionally, this combination inhibited the expression of transcription factors, C/EBPα, C/EBPβ, and PPARγ, and adipogenic factors, FABP4 in mice. In conclusion, oral administration of CP inhibited lipid droplet accumulation and counteracted HFD-induced obesity in mice.

ABSTRACT Pyrrolizidine alkaloid (PA) producing plants like Senecio jacobaea or Senecio vernalis are undesirable in fields for forage production, since PA are toxic to animals and humans. Previous studies have shown that ensiling can decrease the PA content in forages; however, no direct comparison of diverse PA from different Senecio spp. under various ensiling conditions has been made. Therefore, it was hypothesised that individual PA might react differently to ensiling, and silage inoculation with Lactobacillus will affect PA degradation because of a quick drop in pH, contrastingly to poor silage qualities resulting from contamination with soil. Laboratory scale grass silages were prepared in a multifactorial design with two levels of dry matter contents, four ensiling treatments and two storage durations (10 and 90 d). For each combination, four replicates were prepared individually. Ensiling treatments were (1) 10 ml water per kg fresh matter as control (CON), (2) 10 ml heterofermentative Lactobacillus buchneri strain LN4637 at 3 · 105 cfu/kg fresh matter plus 25 g molasses/kg fresh matter (LBHE), (3) 10 ml homofermentative lactobacilli at 3 · 105 cfu/kg fresh matter plus 25 g molasses/kg fresh matter (LBHO) and (4) 10 g soil/kg fresh matter (SOIL). Treatments affected formation of fermentation acids. Acetic acid was highest with treatment LBHE, and butyric acid was highest with treatment SOIL. All ensiling treatments effectively reduced total PA content by degrading the PA N-oxide (PANO) fraction. In parallel, though, the fraction of the tertiary base forms increased by around one-tenth of the original PANO content. Contents of jaconine and senkirkine were higher after ensiling than before, with regards to the sum of PA and PANO for jaconine, indicating higher stability or new formation through degradation of other PA. Overall, ensiling offers opportunities to decrease the PA-PANO content in feed and therefore lowers the risk of intoxication by Senecio in livestock.

ABSTRACT Straw is the main by-product of grain production, used as bedding material and animal feed. If produced or stored under adverse hygienic conditions, straw is prone to the growth of filamentous fungi. Some of them, e.g. Aspergillus, Fusarium and Stachybotrys spp. are well-known mycotoxin producers. Since studies on mycotoxins in straw are scarce, 192 straw samples (wheat n = 80; barley n = 79; triticale n = 12; oat n = 11; rye n = 12) were collected across Germany within the German official feed surveillance and screened for the presence of 21 mycotoxins. The following mycotoxins (positive samples for at least one mycotoxin n = 184) were detected: zearalenone (n = 86, 6.0–785 μg/kg), nivalenol (n = 51, 30–2,600 μg/kg), deoxynivalenol (n = 156, 20–24,000 μg/kg), 15-acetyl-deoxynivalenol (n = 34, 20–2,400 μg/kg), 3-acetyl-deoxynivalenol (n = 16, 40–340 μg/kg), scirpentriol (n = 14, 40–680 μg/kg), T-2 toxin (n = 67, 10–250 μg/kg), HT-2 toxin (n = 92, 20–800 μg/kg), T-2 tetraol (n = 13, 70–480 μg/kg). 15-monoacetoxyscirpenol (30 μg/kg) and T-2 triol (60 μg/kg) were only detected in one barley sample. Macrocyclic trichothecenes (satratoxin G, F, roridin E, and verrucarin J) were also found in only one barley sample (quantified as roridin A equivalent: total 183 μg/kg). The occurrence of stachybotrylactam was monitored for the first time in four samples (n = 4, 0.96–7.4 μg/kg). Fusarenon-X, 4,15-diacetoxyscirpenol, neosolaniol, satratoxin H and roridin-L2 were not detectable in the samples. The results indicate a non-negligible contribution of straw to oral and possibly inhalation exposure to mycotoxins of animals or humans handling contaminated straw.