Animal Feed Science and Technology最新文献

This study investigated the effect of replacing soybean meal (SBM) with poultry by-product meal (PBM) in grower-finisher diets on pig feeding, growth performance, carcass yield and meat quality. The replacement levels were increased from no PBM (PBM0) to 37 g/kg PBM (PBM37), 85 g/kg PBM (PM85) and 111 g/kg PBM (PBM111). All diets met or exceeded nutrient requirements for pigs between 20 – 100 kg live weight (NRC, 2012). Sixty-four entire males (PIC 337 x PIC Camborough 42), at an average live weight (LW) of 27.60 ± 2.48 kg (mean ±SD) were blocked by LW and randomly assigned to 8 pens, with each diet replicated across 2 pens. Pigs had ad libitum access to diets via electronic feeders until they reached approximately 100 kg LW, at which time they were slaughtered. Results showed no significant effect of replacing SBM with PBM on pig feeding behavior parameters and the majority of pig growth performance, carcass yield, and meat quality traits, with the exception of higher feed conversion ratio (FCR) in pigs fed the PBM37 diet. Loin muscles from the group fed the PBM111 diet had significantly lower ultimate pH and a greater cooking loss than the other treatments (P < 0.05). Loin muscles from pigs fed high levels of PBM (PBM85 and PBM111) had greater ash content than those fed the PBM37 and control diets (P = 0.001). Overall, the present research indicated that PBM could be a viable primary protein source in diets for growing-finishing pigs, as it did not appear to have any adverse effects on pig feeding behavior, growth performance and meat quality. In addition, PBM is potentially a good source of calcium and phosphorus for growing–finishing pigs. However, due to the variation in quality and composition of available PBM, it is essential to measure nutritional composition before including PBM in diets for growing-finishing pigs.

Black soldier fly larvae (BSFL) have the potential to be incorporated into equine feed as a sustainable and nutritionally dense insect-derived source of protein and fat. The purpose of this study was to investigate the suitability of whole dried BSFL as a novel protein source in equine diets based on acceptability, palatability, and various health parameters. Seventeen horses (15.2 ± 7.0 years; 596 ± 122 kg body weight (BW) (mean±SD)) and three ponies (19.7 ± 0.6 years; 364 ± 53 kg) were separately fed a BSFL-based supplement (TRT) and a roasted soybean-based supplement (CON) (0.75 g crude protein per kg BW^0.75) for 28-days using a cross-over study design. Feed intake was recorded throughout the feeding periods to assess the acceptability of the novel ingredient. Body weight, body condition score (BCS), plasma biochemistry, and complete blood counts were assessed at the beginning and end of each treatment period as markers of health status. After the cross-over study, two-bowl tests were used to assess the palatability of the BSFL supplement, with or without the presence of other concentrates. Minimal differences were observed between treatment groups for biochemical analytes and complete blood counts, and BW and BCS did not change throughout the study period. Both supplements were willingly consumed by the horses over the 28-day feeding periods, though feed intake was 8% greater in the CON compared to the TRT group (P<0.01). For the palatability tests, horses first approached (P=0.03) and first consumed (P=0.03) the CON more frequently than the TRT supplement when the supplements were supplied with other concentrates. When the supplements were offered in the absence of other concentrates, there was no difference in which bucket was approached first, but horses tended to first consume the CON rather than the TRT supplement. Overall, these data indicate that dietary consumption of BSFL for 28 days at a low-inclusion rate results in no negative health outcomes in horses; however, longer-term studies are warranted to further examine physiological effects of consuming BSFL and at higher inclusion rates. Though horses did favour the CON supplement based on palatability parameters, horses willingly consumed the BSFL supplement, indicating that BSFL at low inclusion rates may be considered a palatable ingredient in equine diets.

Two experiments were carried out to evaluate whether the fermentability coefficient (FC) concept is applicable to Megathyrsus and Urochloa genera and whether the forage nitrate content alters the fermentation pattern of the respective silages. Guinea grass [Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L. Jacobs (Syn. Panicum maximum Jacq.) cv. MG18 Aries II] and palisade grass [Urochloa brizantha (Hochst. ex A. Rich) R.D. Webster (syn. Brachiaria brizantha (A. Rich) Stapf) cv. Marandu] were used in both experiments. In experiment 1, a broad range of FC was induced by different dry matter (DM) content and soluble carbohydrates (SC):buffering capacity (BC) ratio. The DM content was modified by wilting (i.e., guinea grass: direct cut at ∼200 g/kg, wilted to ∼300 and ∼400 g/kg; palisade grass: direct cut at ∼250 g/kg and wilted to ∼400 g/kg) while the SC:BC ratio was modified by addition of glucose [0, 5 and 10 g/kg of fresh matter (FM)] resulting in a factorial arrangement of 3 × 3 for guinea grass and 2 × 3 for palisade grass, with three replications per treatment. In experiment 2, five doses of sodium nitrate (0, 0.15, 0.30, 1.5 and 3.0 g/kg FM) were added factorially to DM and glucose levels used in experiment 1, leading to a factorial arrangement of 3 × 3 × 5 for guinea grass and 2 × 3 × 5 for palisade grass, with three replications per treatment. Regression analyses were performed using the REG procedure of SAS. An independent dataset of tropical grasses and their silages (n = 226) was used to validate the FC model. The FC equation obtained for tropical grasses in the current study did not diverge from the model derived from temperate forages (i.e., FC = DM + 80 × SC:BC), as the regression slopes were similar (79 vs. 80; P = 0.92). There was a linear negative correlation between FC and minimum content of nitrate required to inhibit butyric fermentation, confirming the clostridia-inhibiting role of nitrate in tropical grass silages too. However, the effect size differed between grass genera. In conclusion, as proposed for temperate forages, FC values ≥350 markedly decreases the risk of butyric fermentation, whereas FC values ≥400 completely suppress butyric fermentation in tropical grasses with moderate levels of nitrate and epiphytic lactic acid bacteria (LAB). The FC required to curtail butyric fermentation decreased linearly with nitrate concentration. Nevertheless, the minimum nitrate content to inhibit Clostridium development during silage fermentation depended on the forage species.

Livestock production in southern South America heavily relies on extensive native grasslands, characterized by high plant species diversity, which makes estimating forage digestibility and intake by ruminants in this pastoral ecosystem challenging. Therefore, the aim of this study was to develop regression models to establish the relationship between total faecal nitrogen excretion (FNe) and organic matter (OM) intake, and faecal nitrogen content (FNc) and OM digestibility in sheep fed multi-species native forage. In a completely randomized design, 16 Corriedale sheep averaging 44 kg of body weight (BW) were housed in metabolism cages and received forage in amounts of 15, 20, 25 g of dry matter per kg of BW or ad libitum. During the spring of 2019 and the summer of 2020, four measurement periods were carried out. The sheep had 5 days of adaptation to the metabolism cage, 10 days to adapt to the treatments of amounts of forage offered, and 5 days for intake and digestibility measurements. The forage was harvested once a day, and then the fresh forage was offered at two different times, 8 and 17 h. A linear regression model was developed to estimate OM intake in sheep fed multi-species native forage based on the FNe [Intake (g OM/sheep/day) = 107.7 + 101.5 × FNe]. An exponential regression model was developed to estimate forage OM digestibility in sheep based on the FNc (Digestibility = 0.31411e^{0.02995 × FNc}). In conclusion, our findings highlight that the OM intake can be precisely estimated using FNe and a reasonably precise estimation of the forage OM digestibility can be reached by assessing FNc in sheep fed a multi-species native forage from the Rio de la Plata region in South America.

Xylooligosaccharides (XOS) are known as prebiotics which promote beneficial gut microbes, improve gut health and the performance of broilers. Xylobiose (XOS2) and xylotriose (XOS3) are two compounds in the XOS group. In ovo feeding could deliver these prebiotics to the embryo, and this is considered as an effective method for studying the effects of the prebiotics during embryonic development and the post-hatch period. This study investigated the effects of in ovo feeding of XOS2 and XOS3 on growth performance, carcass traits, ileal histomorphometry, and immune-related gene expression in broilers. A total of 144 fertilized eggs of Cobb 500 broilers were divided into three groups: (a) non-injected control (CON), (b) XOS2, and (c) XOS3. The eggs from XOS2 and XOS3 groups were injected with 0.5 ml of 0.85% normal saline solution containing 3 mg of XOS2 and 3 mg of XOS3, respectively, into their amniotic sac on the 17th embryonic day. A total of 131 hatched chicks were raised in 18 replicate pens (5 or more chicks per pen) following standard management practices and fed a corn-soybean meal-based diet for 21 days. The feed intake and body weight (BW) data were recorded weekly. The chickens were euthanized on day 7, day 14, and day 21 to collect ileum sections, and the carcass traits were recorded on only day 21. Total RNA was extracted from ileum tissues, and qPCR was performed to measure the gene expression. All the statistical analyses considered the significance level at a P value <0.05. The result showed that in ovo treatments did not affect the hatchability of the eggs. The XOS2 group showed a trend to increase the BW on day 0, compared to CON (P=0.052), and the XOS3 group showed better FCR improvement than the XOS2 group in the first week. There was no difference (P>0.05) among the groups for the weight of the breast muscle, drumsticks, gizzard, proventriculus, and carcass weight at the age of 21 days. The histomorphometry of the ileum on day 7 revealed a significant reduction (P<0.05) of villi height (VH), villi width (VW), and crypt depth (CD) in XOS2, compared to the CON group. On day 7, a lower CD and a higher VH to CD ratio were recorded in XOS3, compared to CON. On day 14, XOS3 showed an increase in VW and villi surface area (VSA) compared to XOS2 birds. On day 7, the expression of IL10 in XOS2 was higher compared to CON and XOS3, and CD56 was significantly higher (P<0.05) in the XOS2 compared to CON group. On day 21, the XOS2 and XOS3 significantly lower the expression of IFNγ. Overall, XOS2 and XOS3 significantly increased immunity until day 21. In conclusion, in ovo XOS feeding demonstrated the potential to modulate gut morphology and immunity of the chickens during the post-hatch days.

The hypothesis that exogenous xylanase added to diets for gestating and lactating sows will increase the apparent total tract digestibility (ATTD) of gross energy (GE) and total dietary fiber (TDF), increase digestible energy (DE) and metabolizable energy, and improve the reproductive performance of sows was tested. Two diets for gestating sows and two diets for lactating sows were formulated without or with 100 g per ton of an exogenous xylanase (16,000 units/kg). Diets were fed in two consecutive reproductive cycles. From 106 animals, 48 pregnant sows, organized in 4 blocks of 12 sows (6 sows per treatment in each block), were placed for 10 days in metabolism crates starting on day 35 (mid-gestation) and again on day 95 (late-gestation) with feces and urine being collected for 4 days. Sows were moved to the lactation unit on day 106 of gestation and feeding of lactation diets was initiated. Fecal samples were collected (grab-sampling) from days 10–14 post-farrowing. The number and weight of pigs born, mummified, stillborn, and weaned per sow were recorded, and survival rate and litter average daily gain were calculated. Litters were weaned on day 20 ± 1. All animals were rebred and 46 sows were placed in metabolism crates in mid and late-gestation as in the first cycle, and treatments in the farrowing unit during the second cycle were also as in the first cycle; however, colostrum and milk samples were collected from sows in the second cycle. Results indicated that reproductive performance was not different between sows fed control diets and sows fed diets with xylanase during the two reproductive cycles. In the first gestation period, the ATTD of TDF in late-gestation was greater (P < 0.05) in sows fed the diet with xylanase than in sows fed the control diet. During the first lactation, sows fed the diet with xylanase had greater (P < 0.05) ATTD of GE and TDF, and greater (P < 0.05) DE than sows fed the control diet. During the second gestation, sows fed the diet with xylanase had greater (P < 0.05) DE in mid-gestation. During the second lactation, sows fed the diet with xylanase had greater (P < 0.05) ATTD of GE and TDF, and greater (P < 0.05) DE than sows fed the control diet. In conclusion, DE was greater in diets with xylanase than in control diets during the two reproductive cycles, and sows fed the lactation diet with xylanase had greater digestibility of fiber than sows fed the control diet.

Whole-plant corn silage is an important forage for ruminant livestock; however, it is vulnerable to contamination by spoilage molds and mycotoxins because corn is an excellent substrate for fungal growth. Mycotoxins in corn silage have been found to significantly impair the productivity, health status, and fertility of dairy herds. It is urgent to develop a biological control strategy to prevent toxigenic fungi and mitigate mycotoxins in silage. This study aimed to evaluate the biocontrol potential of two novel isolated strains against toxigenic fungi and their toxins in corn silage. Acetobacter tropicalis AT7 and Lactiplantibacillus plantarum LP64 were isolated from mold-contaminated silages based on their potential antifungal and detoxifying properties. The antifungal activity of the two strains was affected by pH and heating, the antifungal compounds against A. flavus might be proteinaceous substances. The supernatants and cell pellets of the two isolates exhibited mycotoxin removal abilities for Aflatoxin B₁ (AFB₁), Zearalenone (ZEN), and Deoxynivalenol (DON), indicating that both adsorption and biodegradation contributed to mycotoxin detoxification. The two strains were ensiled with artificial fungal-infected (FI) or non-fungal-infected (NFI) whole-plant corn for 180 d. The FI silages had higher concentrations of aflatoxin B₁ and deoxynivalenol than NFI silages. Both A. tropicalis AT7 and L. plantarum LP64 decreased aflatoxin B₁ and zearalenone concentrations. Two strains affected the bacterial and fungal communities during the ensiling, indicated by the decline in the relative abundance (RA) of Pseudopithomyces and Periconia as compared to untreated corn silages. Inoculating A. tropicalis AT7 increased microbial network stability of NFI silages. In summary, A. tropicalis AT7 has the potential to be used as a biological preservative for reducing mycotoxigenic fungi and mycotoxin contamination in silages.

To investigate the effects of luteolin (LUT) on the growth, antioxidant capacity, non−specific immunity and intestinal microbiota of red swamp crayfish (Procambarus clarkii), 300 individual crayfish (4.17 ± 0.50 g average body weight and 50.19 ± 1.40 mm average body length) were randomly divided into five groups and fed with LUT doses of 0 mg/kg (CG), 50 mg/kg (LG50), 100 mg/kg (LG100), 300 mg/kg (LG300), and 500 mg/kg (LG500) for 8 weeks, respectively. Firstly, the results demonstrated that the survival and growth performance were significantly improved in all LUT added groups compared to the control (CG group), with no significant differences in hepatosomatic index, feed coefficient and muscle components, and the crayfish in LG100 group showed the maximal survival rate (SR) and specific growth rate (SGR) (P < 0.05). Secondly, histological observations displayed that the hepatopancreas and intestine tissues were not impacted in the LUT−supplemented groups, and the length of intestinal folds was significantly increased in LG100 and LG300 groups. Thirdly, LG50, LG100, and LG300 groups produced significantly increased hepatopancreatic antioxidant enzyme activities and hemolymph immune indicators compared with the control. In all experimental groups, malondialdehyde (MDA) contents were significantly reduced, as were aspartate aminotransferase and alanine aminotransferase activities. Lastly, dietary LUT specifically improved the structure and optimized the function of the gut microbiota. Compared to the control, the LG100 group displayed a significant increase in the index of Chao1 and Observed species, an increase in the relative abundance of Proteobacteria and Actinobacteria, a decrease in the ratio of Bacteroidetes to Firmicutes, and an increase in the abundance of Thermomonas, Turicibacter, Bdellovibrio and Enterococcus. PICRUSt analysis demonstrated a significant improvement in the KEGG pathway associated with isoflavone biosynthesis in the LG group. In conclusion, the present study confirms that dietary supplementation with 50−300 mg/kg LUT favors growth, non−specific immunity and antioxidant function in P. clarkii, with optimal additions ranging from 102−165 mg/kg. Furthermore, it optimized gut microbiota function, suggesting that LUT can be used as a potential feed additive for P. clarkii. These findings provide new insights for crayfish’s healthy culture.

Two experiments were conducted to test the null hypothesis that there are no differences in the standardized ileal digestibility (SID) of amino acids (AA) and metabolizable energy (ME) among three sources of high-protein distillers dried grains (HP-DDG) fed to weanling pigs. The three sources included an experimental HP-DDG product and two commercial HP-DDG products (i.e., HP-DDG 40 and HP-DDG 50) that were fed to weanling pigs. In experiment 1, eight barrows (initial body weight: 11.09 kg) were allotted to one of four diets using a replicated 4 × 4 Latin square design with four diets and four periods of seven days in each square. A nitrogen-free diet and three diets containing each source of HP-DDG as the sole source of AA were prepared. Results indicated that values for the SID of Lys in the experimental HP-DDG; HP-DDG 50, and HP-DDG 40 were 0.524, 0.638, and 0.642, respectively. The SID of most AA in the experimental HP-DDG was less (P < 0.05) than in the other sources of HP-DDG, but no differences were observed between HP-DDG 40 and HP-DDG 50. In experiment 2, thirty-two weanling pigs (initial body weight: 18.0 kg) were randomly allotted to one of four diets. A corn diet was formulated to contain corn as the sole source of energy and three additional diets contained corn and each source of HP-DDG. Pigs were housed individually in metabolism crates and feces and urine were collected separately for four days after five days of adaptation. Digestible energy (DE) and ME in the three sources of HP-DDG were calculated by difference. Results from experiment 2 indicated that the apparent total tract digestibility (ATTD) of gross energy (GE) in the corn diet was greater (P < 0.05) than in the diets containing the experimental HP-DDG or HP-DDG 40, and the ATTD of GE in the diets containing the experimental HP-DDG or HP-DDG 50 was greater (P < 0.05) than in the diet containing HP-DDG 40. On a dry matter basis, ME in the experimental HP-DDG, HP-DDG 40, and HP-DDG 50 were 17.05, 16.72, and 18.23 MJ/kg, respectively, with the ME of HP-DDG 50 being greater (P < 0.05) than in HP-DDG 40, but not different from the ME in the experimental HP-DDG. In conclusion, the SID of most AA in HP-DDG 40 and HP-DDG 50 was greater than in the experimental HP-DDG. The DE and ME in HP-DDG 50 was greater than in HP-DDG 40, but DE and ME in HP-DDG 40 were not different from DE and ME in the experimental HP-DDG.

Achieving optimal nutrient composition in locally sourced ruminant feeds is important, but can be challenging in resource-limited production systems. For example, improving the composition of available local feed resources is a key obstacle to efficiently mitigating enteric methane (CH₄) emissions in ruminants. This study characterized the nutritional content and in vitro methane (CH₄) yield of ruminant feedstuffs accessible in Ethiopia. A survey of 60 experienced farmers in two representative districts in Amhara region, Ethiopia, provided 33 feed samples, which were classified into four ruminant feed categories: Grasses (n=10); indigenous plants (trees, shrubs, herbaceous plants) (n=13); crop residues (n=5); and agro-industrial by-products (n=5). Nutritional composition was assessed by proximate and detergent methods. Methane yield (g CH₄/kg feed dry matter (DM)) and total gas yield (L/kg DM) were evaluated using a fully automated in vitro gas production system. A colorimetric assay was conducted to measure condensed tannin content (CT, mg/g) in relevant feeds. Lower crude protein (CP) values were observed for the grass (mean 65.2 g/kg DM) and crop residues (mean 54.5 g/kg DM) categories. Agro-industrial by-products had the highest CP (mean 260 g/kg DM), while indigenous plants exhibited intermediate levels (163 g/kg DM). There was significant variation in CH₄ yield (P<0.01) between grasses (12.4–24.7 g/kg DM) indigenous plants (1.8–19.3 g/kg DM), and agro-industrial by-products (8.1–26.9 g/kg DM). The indigenous plant Trifolium acaule gave the lowest in vitro CH₄ yield (1.8 g/kg DM). A positive relationship was observed between in vitro dry matter digestibility (IVDMD), CH₄, and total gas yield. Percentage of CH₄ in total gas production varied with feed category (grasses 14.5–19.6%; indigenous plants 3.1–16.9%; crop residues 15.8–20.6%; agro-industrial by-products 12.8–18.7%), and within category, e.g., Trifolium acaule (3.1%), Acacia nilotica L. (7.1%), Ziziphus spina-christi (9.9%), brewer’s spent grains (BSG) (12.8%), local liquor (areki) residues (14.1%), and local beer (tella) residues (15.1%). A negative relationship was observed between CT content and in vitro CH₄ yield, with a stronger (P<0.05) correlation for soluble CTs (R² = 0.46) than cell-bound CTs (R² = 0.25) and total CTs (R² = 0.29). Based on methanogenic properties and effects of CTs on in vitro CH₄ yield, indigenous plants should be prioritized in ruminant rations in Ethiopia. Making nutritional composition and CH₄ data publicly available could help develop environmentally sound, cost-effective rations for ruminant livestock, benefiting local farmers and leading to more sustainable and efficient livestock production