Animal Feed Science and Technology最新文献

This study aimed to enrich corn and alfalfa silages with γ-aminobutyric acid (GABA) by utilizing high GABA-producing Lentilactobacillus buchneri. Eleven strains were screened and L. Buchneri YM9 was distinguished for its superiority in GABA production, and it was subsequently applied as an inoculant on whole-crop corn and alfalfa silage. The silage treatments were control (without inoculant), AH35 (non-GABA producing strain), YM9 (high-GABA producing strain), and 40788 (commercial GABA producing strain). The results revealed that in corn silage, pH significantly declined at the initial ensiling stage (3–7 days), with the control having the lowest pH after 90 days. The control also exhibited the highest lactic acid, while L. buchneri treatments had elevated acetic acid. Similar trends were observed in alfalfa silage, with 30 % dry matter (DM) showing lower pH and higher organic acids. YM9-inoculated corn silage had higher DM loss, reduced water-soluble carbohydrates (WSC), but increased crude protein (CP) content. YM9 and 40788 treatments in whole-crop corn silage had lower glutamate (Glu) content post-ensiling, signifying effective GABA production. YM9 treatment maintained stable and higher glutamate decarboxylase (GAD) activity, resulting in the highest GABA accumulation in corn silage (1.97 g/kg DM). Likewise, YM9 and 40788 demonstrated significantly higher GABA content in 30 % (7.6 and 6.51 g/kg DM) and 40 % (5.23 and 5.32 g/kg DM) DM alfalfa silage. Beyond enhancing fermentation and nutrient preservation, YM9 strain shows promise in enriching whole-crop corn and alfalfa with ample GABA concentration, potentially exerting anticipated biological functions when consumed by animals.

Sardine cooking wastewaters are by-products of the canning industry with great potential for valorisation. We have hypothesized that they can be a source of aromas to enhance appetite when added to plant-based diets. The poor palatability of such diets often described in carnivorous species poses a recurring problem in fish farming, with harsh consequences on fish growth performance and flesh quality. Aromas from sardine cooking wastewaters were collected without processing (CW-A), processed through vacuum distillation (VD-A), or processed through liquid/liquid extraction with soybean oil (LLE-A) into plant-based diets. Each aroma was added to a plant-protein based diet for European seabass, at a concentration of 2 μg of 1-penten-3-ol/g diet, resulting in 3 experimental diets (CW, VD and LLE). A non-supplemented diet was used as a control. Each diet was assigned to triplicate fish groups (initial weight 95.7 g), that were hand-fed twice daily until apparent satiation in a recirculating saltwater system at 21 °C. After 18 weeks, fish growth performance and nutrient utilisation were evaluated. The expression in the brain of neuropeptides involved in feed intake regulation was also analysed. Moreover, flesh colour and texture were assessed instrumentally and by sensory analysis using a consumer panel. Fish fed LLE displayed a significantly higher feed intake than those fed CW which was correlated with an increased neuropeptide Y expression in the hypothalamus. However, LLE slightly hindered lipid metabolism, leading to lower available glucose and resulting in statistically similar final weights among diets. Despite variations in fillet hardness, the sensory panel revealed similar overall liking across all treatments. The findings indicate that aromas from sardine cooking wastewaters can modulate feed intake, but further refinement in processing or incorporation levels is required to potentiate their efficacy.

This study assessed the effects of dietary inclusion of solid-state fermented (SSF) brewer’s spent grain (BSG) with Aspergillus ibericus on nutrient and energy digestibility, digestive enzyme activity, and intestinal histomorphology of juvenile European seabass (Dicentrarchus labrax). Five diets (18 % crude lipids and 45 % crude protein) were formulated, including a control diet (without BSG), two diets with 10 % and 20 % unfermented BSG (10BSG and 20BSG), and two other diets with 10 % and 20 % fermented BSG (10BSG-SSF and 20BSG-SSF). SSF affected the BSG's nutritional composition, including a 21 % increase in protein content and reductions in lipid (49 %), cellulose (30 %), hemicellulose (34 %), and lignin (7.3 %) content. Antioxidant activity and total phenolic compounds were minimal before SSF but significantly increased after SSF. Dietary incorporation of 20 % BSG-SSF increased the digestibility of dry matter (p<0.01), protein (p=0.03), isoleucine (p=0.03), glutamate (p=0.02), lipids (p=0.04) and energy (p=0.04) compared to the 20BSG diet. Moreover, SSF also modulated digestive enzyme activity, reducing total protease (p=0.03) and trypsin (p=0.01) activities in fish fed the 10BSG-SSF diet compared to the control diet. Fish fed the 20BSG diet showed changes in intestinal histomorphology compared to those fed the control diet, and SSF of BSG appeared to mitigate these effects.

Overall, these results indicate that SSF is a promising technique for enhancing the nutritional quality of low-value agro-industrial by-products, such as BSG, increasing their potential use as feed ingredients and contributing to reducing the climate and environmental footprint of aquaculture production.

Microwave (MW) treatment has been suggested to improve forage hays' nutritive value and sheep growth performance. However, the extent to which the MW-treated forage hay affects apparent digestibility and nitrogen partitioning is not documented. This study examined the potential to use the MW as a novel thermal treatment to improve forage hay intake, digestibility, and nitrogen utilisation of sheep. A total of 24 merino rams (18 months of age, 42 ± 2.0 kg initial body weight) were randomly divided into four dietary treatments: Control lucerne hay (CLH), MW-treated lucerne hay (MLH), Control wheat hay (CWH), and MW-treated wheat hay (MWH). The study had 14 days adaption and 7 7-day sample collection period, with 6 sheep replicates/treatment. Feed, faeces, urine, and blood plasma samples were collected. Higher dry matter (DM) intake was observed in MLH vs. CLH (P < 0.001). The DM and organic matter digestibility both increased by 8 % in MLH compared to CLH (P <0.001). The digestibility of neutral detergent fibre (NDF), acid detergent fibre (ADF), and nitrogen increased by 12 %, 9 %, and 10 %, respectively in MLH compared to CLH (P < 0.001). The MLH-feed sheep showed higher nitrogen retention (P = 0.037) and microbial nitrogen synthesis (P = 0.047) compared to CLH-fed sheep. A limited effect was observed in CWH vs. MWH, with only ADF digestibility (P = 0.023) and plasma glucose (P < 0.05) being higher in sheep fed with MWH. Electron microscope images showed clear cell microstructure destruction (P <0.001) due to MW treatment in lucerne hay but there was no difference observed in wheat hay. The result provided first-hand comprehensive data to quantify MW treatment's effect on hay quality and sheep performance, with potential mechanisms explained underpinning the observed changes.

Most fat supplements added to dairy diets are derived from palm acid oil or palm fatty acid distillate. There are environmental concerns about palm oil production due to deforestation and high greenhouse gas (GHG) emissions. The objective of this study was to evaluate a palm-free fat supplement, Envirolac. Envirolac contains vegetable oils, marine oils and glycerine encapsulated within a cellulosic fibre-clay mineral carrier matrix. The carrier matrix has small particle size to facilitate rapid rumen passage and minimal interference with rumen digestion. Fifty cows were divided into two balanced groups of 25 cows. Each group received Control (calcium soap of palm fatty acid distilate, 0.5 kg/d) and Envirolac (0.5 kg/d) diets in a crossover design with two feeding periods of four weeks duration, so that each cow received both diets. Envirolac has a lower total fat concentration than the calcium soap, so the feeding rate delivered less total fat. When fed on Envirolac, cows yielded more milk 40.7 v 40.1 kg/d), energy-corrected milk (ECM; 42.9 v 41.3 kg/d) and milk components (1605 v 1514 g fat, 1239 v 1199 g protein, 1871 v 1839 g lactose, per day), and produced milk with higher concentrations of fat (40.1 v 38.6 g/kg) and protein (30.7 v 30.1 g/kg), than when fed on Control. When fed on Envirolac, cows produced milk with higher concentrations of fatty acids (FA) synthesised de novo in the mammary gland (25.5 v 23.6 g/100 g total FA), lower concentration of palmitic acid (35.5 v 37.2 g/100 g total FA), and higher concentrations of some long-chain fatty acids (C20:0, C20:1, C20:3n3, C21:0, C22:0, C22:6n3 and C23:0), than when fed on Control. There was no effect of treatment on dry matter intake (DMI; mean 23.4 kg/d), so feed efficiency was higher (1.83 v 1.76 kg ECM/kg DMI) for Envirolac than Control. There was no effect of treatment on dry matter digestibility (0.73), methane production (433 g/d), methane yield (19.3 g/kg DMI) or methane intensity (10.9 g/kg ECM). Feed carbon footprint of Envirolac was calculated to be 1028 g CO₂eq/kg DM, which is 0.46 of the value for a calcium soap (2830 g CO₂eq/kg DM), and reduced feed carbon footprint per kg ECM milk production by 11 %. This study demonstrates that Envirolac can replace palm-based fat supplements in dairy diets to improve feed efficiency and reduce the carbon footprint of milk production.

Monascus-fermented cereals reduce methane production from the rumen. The identification of the metabolites responsible of the antimethanogenic effect is important to assess the potential of this strategy as a mitigation option in ruminant production. This study highlights metabolites from Monascus ruber associated to methane inhibition. An in vitro rumen screening test was used to rank solid-state fermented wheat samples for their ability to inhibit methane. Four active and four less-active samples were selected for metabolomics analysis using liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS) and the identity of discriminant variables responsible for this group distinction was assigned thanks to tandem mass spectrometry (MS/MS) experiments. A total of 28 discriminating metabolites were putatively identified based on their accurate m/z values, fragmentation pathways and information from databases. The chemical structure (identification level 1) was confirmed for 9 of them thanks to the available authentic chemical standards. Most of these metabolites belong to the chemical class of statins and their derivatives (n=13), four of them annotated as statin-like molecules were observed here for the first time. A targeted approach using LC-MS/MS was performed to measure the levels of known metabolites and showed that the lovastatin concentration in active samples was 16-fold greater than in least-active samples. Whereas lovastatin was the major metabolite, up to 40 % of the total statins were represented by other statin molecules. Comparison of the functional capability of lovastatin lactone and lovastatin acid demonstrates that the acid form is responsible for the antimethanogenic activity in the rumen environment. This study shows that Monascus-fermented feeds contain a wide variety of statins in both lactone and acid forms. Information from this work provides insight for improving the antimethanogenic efficacy of diets containing bioactive Monascus metabolites in ruminants

Feed restriction during the early life of ewe lambs (F0) triggers the transfer of epigenetic marks to the next generation, thus impairing the reproductive performance of F1. However, the effects of this factor on milk production and composition, including its abundance in regulatory miRNA (many of which are contained in exosomes, small vesicles of endocytic origin that play a role in the modulation of immune response of the offspring) has not been tested so far. Therefore, in this study, the replacement ewe lambs (F0) obtained in a previous project (a group of ewes fed milk replacer ad libitum –ADL– vs. a group of ewes restricted –RES– to 62.5 % the intake level of milk replacer during the suckling period) were raised under similar post-weaning conditions and mated to obtain the progeny (F1). The F1 female lambs were also mated to obtain F2. Milk production was recorded during the peak lactation period of F1, and milk samples were obtained for each gland (udder half) separately to measure chemical composition, somatic cell counts (SCC), and bacteria counts. Moreover, exosomes were also isolated from the milk of each gland separately to obtain the miRNAome following a Next Generation Sequencing approach. No significant differences were found in either milk production of F1, chemical composition of milk (fat, protein, lactase), or bacteriology (colony forming units, CFU). However, SCC was reduced significantly in milk samples of F1-RES dairy sheep, whereas the abundance of five miRNAs was also modified. Thus, oar-miR-150, oar-miR-221, oar-miR-23a, oar-miR-27a, oar-miR-376c were all down modulated in F1-RES when compared to F1-ADL. Most of these miRNAs have been found to play a role in biological functions such as development, apoptosis, muscle differentiation, reproduction, or milk production. However, the exosomes extracted from the milk of these sheep (F1-RES) did not affect the production of IL-9 and IL-2 cytokines after in vitro culture with CaCo-2 cells. This study reveals that nutritional programming events such as feed restriction may drive the abundance of not only SCC but also some milk's bioactive components such as miRNAs, although it is not clear if these changes may modulate the immune response at the intestinal level of the offspring.

Horse preferences for cool season grass cultivars under grazing has been described. However, preference for cool-season grass cultivars as hays has not been widely evaluated in horses, particularly the new varieties of Tall Fescue with novel endophytes designed to produce less ergovaline, the compound to which fescue toxicosis is attributed. First cutting hay was harvested in 2019 and 2020 from seven cool season grasses: Tall Fescue v. KY 31; Tall Fescue v. Bronson, endophyte free; Tall Fescue v. Texoma MaxQ, novel/non-toxic endophyte; Meadow Fescue v. Preval; Festulolium v. Spring Green; Perennial Ryegrass v. Elgon; and Orchardgrass v. Crown Royal. First cutting yield was determined on a dry weight basis. Sub-samples were analyzed for forage quality parameters and ergovaline concentrations. The effect of cultivar on mean hay yields was analyzed using a one-way ANOVA, and since the F-Value was significant (< 0.001) the least significant differences were further determined to compare yield differences among the cultivars. All three Tall Fescue cultivars, Meadow Fescue, and Festulolium had significantly greater yields than the Perennial Ryegrass and Orchardgrass (P < 0.05). All samples tested for ergovaline were below the reporting threshold of the laboratory. Subsequently, tillers of the Tall Fescue cultivars were evaluated for endophyte presence. Endophyte was detected in only 3.3 % and 16.7 % of v Bronson and Texoma MaxQ tillers, respectively. No endophyte was detected in v KY 31. To evaluate preference four mature idle horses (6 ± 1.08 yrs) were fasted 30 min prior to being in the test stalls for 30 min. First choice and weight consumed were recorded. Preference testing occurred within harvest year. Equine preference data were analyzed within year using a one-way ANOVA pairwise comparison with the Tukey-Kramer adjustment for multiple comparisons. Both forward and backward stepwise regression modelling were used to investigate proximate analyses values as potential predictors of cultivar consumption by the horses during the preference tests. The best performing model explained 36 % of the variation in cultivar consumption. Based on amounts consumed horses had similar preferences each year; the overall rank of the cultivars was very similar with only the two least preferred cultivars transposed from 2019 to 2020. Horses most preferred the lowest yielding cultivars (Perennial Ryegrass and Orchardgrass). Despite low ergovaline and endophyte content in the Tall Fescue varieties, adult horses preferred hay of other cultivars. Festulolium is an option for hay producers that balances both yield and horse preference.