Potential effect of the microbial fermented feed utilization on physicochemical traits,antioxidant enzyme and trace mineral analysis in rabbit meat

The study investigated the potential effect of the microbial fermented feed utilization on physicochemical traits, antioxidant enzyme and trace mineral analysis in rabbit meat. A total of 72 six-week-old male rabbits were weighed and randomly divided into four groups (1) (SRKC) control; (2) (SRKP) Lactobacillus plantarum 1 × 10⁶ cfu/g fresh weight (FW); (3) (SRKG) Pediococcus acidilactici 1 × 10⁶cfu/g FW and (4) (SRKPG) P. acidilactici + L. plantarum 1 × 10⁶ cfu/g FW. Performance characteristic, weekly body weight, was positively (p < .05) enhanced, while daily feed intake (DFI) and feed convention ratio (FCR) were not influenced in treatments group as compared to untreated. The water, protein, water holding capacity (WHC) and dry matter (DM) concentration were positively (p < .05) influenced, while ash, pH, lightness, redness and yellowness were not influenced in treated group as compared to untreated. The concentration of glutathione peroxidase (Gpx), superoxide dismutase (SOD) and aspartate aminotransferase (AST) was positively (p < .05) influenced in treatments group as compared to control. Regarding trace minerals, copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn) were positively (p > .05) reduced in treated group as compared to untreated. It is concluded that the addition of lactic acid bacteria (L. plantarum and P. acidilactici) in Hybrid pennisetum silage had a constructive influence on rabbit health performance and meat biochemistry.     

Efficacy of l-glutamic acid,N,N-diacetic acid to improve the dietary trace mineral bioavailability in broilers

Trace minerals are commonly supplemented in the diets of farmed animals in levels exceeding biological requirements, resulting in extensive fecal excretion and environmental losses. Chelation of trace metal supplements with ethylenediaminetetraacetic acid (EDTA) can mitigate the effects of dietary antagonists by preserving the solubility of trace minerals. Lack of EDTA biodegradability, however, is of environmental concern. l-Glutamic acid, N,N-diacetic acid (GLDA) is a readily biodegradable chelating agent that could be used as a suitable alternative to EDTA. The latter was tested in sequential dose–response experiments in broiler chickens. Study 1 compared the effect of EDTA and GLDA in broilers on supplemental zinc availability at three levels of added zinc (5, 10, and 20 ppm) fed alone or in combination with molar amounts of GLDA or EDTA equivalent to chelate the added zinc, including negative (no supplemental zinc) and positive (80 ppm added zinc) control treatments. Study 2 quantified the effect of GLDA on the availability of native trace mineral feed content in a basal diet containing no supplemental minerals and supplemented with three levels of GLDA (54, 108, and 216 ppm). In study 1, serum and tibia Zn clearly responded to the increasing doses of dietary zinc with a significant response to the presence of EDTA and GLDA (P < 0.05). These results are also indicative of the equivalent nutritional properties between GLDA and EDTA. In study 2, zinc levels in serum and tibia were also increased with the addition of GLDA to a basal diet lacking supplemental trace minerals, where serum zinc levels were 60% higher at the 216 ppm inclusion level. Similar to the reported effects of EDTA, these studies demonstrate that dietary GLDA may have enhanced zinc solubility in the gastrointestinal tract and subsequently enhanced availability for absorption, resulting in improved nutritional zinc status in zinc-deficient diets. As such, GLDA can be an effective nutritional tool to reduce supplemental zinc levels in broiler diets, thereby maintaining health and performance while reducing the environmental footprint of food-producing animals.     

微量元素氨基酸螯合物及其在动物生产中的应用

微量元素氨基酸螯合物是一种新型有机矿物元素添加剂,被称为第三代微量元素添加剂。由于其稳定性好、生物效价高、易消化吸收、抗干扰性强等特点,迅速成为动物营养研究的热点,在各种动物生产中广泛应用。本文就微量元素氨基酸螯合物的概念、营养特性、作用机制及在动物生产中的应用进行综述。     

Impact of trace mineral source on beef replacement heifer growth,reproductive development,and biomarkers of maternal recognition of pregnancy and embryo survival

Trace minerals are known to play important roles in early embryo development. The study objective was to determine effects of trace mineral source on heifer reproductive performance. Beef heifers (n = 129) were randomly assigned to one of two treatments. From weaning through breeding, all heifers were individually fed a basal diet supplemented with cobalt (Co), copper (Cu), manganese (Mn), and zinc (Zn) either from organic sources (COMP; Cu, Mn, and Zn amino acid complexes and Co glucoheptonate; Availa-4, Zinpro Corporation, Eden Prairie, MN) or inorganic sources (INORG; Cu, Mn, and Zn hydroxychlorides; Intellibond C, M, and Z, Micronutrients, Indianapolis, IN) and Co as CoSO₄. Blood samples and a reproductive tract score (RTS) were collected to determine pubertal status. All animals were synchronized and artificially inseminated. Pregnancy status was determined by lymphocyte gene expression, circulating concentrations of pregnancy-associated glycoproteins (PAGs), and by transrectal ultrasonography after artificial insemination. Embryonic loss was defined as when a previously pregnant animal was subsequently diagnosed not pregnant. Data were analyzed using the MIXED procedure in SAS. Puberty (P = 0.44), pelvic area (P = 0.74), RTS (P = 0.49), and estrus expression (P = 0.82) were not influenced by treatment. There was no effect of treatment (P = 0.37) or treatment by time (P = 0.19) on pregnancy, but there was a tendency (P = 0.13) for decreased embryonic loss among COMP heifers (27 ± 6%) compared to INORG heifers (38 ± 6%). There was a treatment by pregnancy status by time interaction (P < 0.01) on circulating PAG concentrations with PAG concentrations tending (P = 0.08) to be greater on day 25 among heifers in the COMP treatment compared to heifers in the INORG group. In summary, source of trace mineral did not affect puberty, RTS, pelvic area, or overall pregnancy success, but feeding complexed trace minerals tended to increase circulating PAG concentrations and embryo survival.     

微量元素添加模式对肉鸡生长性能、微量元素代谢和血浆抗氧化性能的影响

本试验旨在研究不同微量元素添加模式对肉鸡生长性能、微量元素代谢和血浆抗氧化性能的影响。选取720羽1日龄科宝(Cobb-500)肉鸡,随机分为4个组,每个组10个重复,每个重复18只鸡。行业标准组:按照农业行业标准NY/T 33—2004添加铜、铁、锌和锰。NRC标准组:按照NRC(1994)推荐量添加铜、铁、锌和锰。NRC比例组:实测基础饲粮中铜、铁、锌、锰的含量,以过量最多的铜(相对于NRC标准)的倍数补齐其余3种元素。相对生物学效价组:假设基础饲粮中微量元素的生物学利用率为额外添加硫酸盐的30%,对其含量进行校准后按照NRC比例组的方法添加。微量元素都以硫酸盐形式添加,试验期42 d。结果表明:1)不同微量元素添加模式未对肉鸡生长性能和死亡率造成显著差异(P0.05)。2)21日龄时,NRC比例组肉鸡十二指肠铜转运蛋白1(Ctr1)的mRNA相对表达量显著高于其余各组(P0.05),NRC比例组和相对生物学效价组肉鸡十二指肠二价金属转运蛋白1(DMT1)的mRNA相对表达量显著高于其余2组(P0.05);42日龄时,NRC标准组和相对生物学效价组肉鸡十二指肠DMT1的mRNA相对表达量显著高于其余2组(P0.05);各组间21和42日龄肉鸡十二指肠锌转运蛋白1(Zn T1)和锌转运蛋白5(Zn T5)的mRNA相对表达量没有显著差异(P0.05)。3)21日龄时,NRC比例组和相对生物学效价组肉鸡血浆总抗氧化能力(T-AOC)显著高于其余2组(P0.05);42日龄时,与相对生物学效价组相比,NRC比例组肉鸡血浆过氧化氢酶(CAT)活性显著下降(P0.05)。4)粪便中微量元素浓度和饲粮的微量元素添加浓度存在显著的正相关关系(P0.05)。由此可见,从微量元素吸收效率和肉鸡血浆抗氧化性能来看,考虑基础饲粮微量元素相对生物学效价并按NRC比例添加是更适宜的添加模式,同时减少了粪便中微量元素的排泄。     

Effects of Phytase Addition with or Without a Trace Mineral Premix on Growth Performance,Bone Response Variables,and Tissue Mineral Concentrations in Commercial Broilers

Microbial phytase has been shown to increase the availability of Ca, P, ME, amino acids, and trace minerals in diets of broilers. By increasing the availability of trace minerals, phytase may be able to replace the trace mineral premix in diets for broilers. Therefore, a 43-d floor pen study that included diets with and without phytase and with and without supplemental trace minerals was conducted to evaluate this possibility. The Ca and nonphytate P concentrations were decreased by 0.10% in diets with phytase. Growth performance was not affected in chicks fed diets with or without the trace minerals, but adding phytase had positive effects on growth performance. Removal of the trace minerals had a negative effect on bone strength. Removal of the trace minerals, addition of phytase, or both had variable effects on tissue trace mineral concentrations.     

Effect of different sources and levels of selenium on performance,meat quality,and tissue characteristics of broilers

The objective of this study was to evaluate the effects of dietary levels of inorganic and organic selenium (Se) on performance, meat physicochemical characteristics, and Se deposition in the tissues of broilers chickens. A total of 2,880 one-day-old broilers (Cobb 500 strain) were divided into 96 experimental pens of 30 birds each. The 12 experimental treatments were arranged in a factorial design of 4 × 3 [selenium levels of 0.15, 0.30, 0.45, and 0.60 ppm, and organic (selenium yeast, SY) or inorganic (sodium selenite, SS) sources of selenium and their association (SY + SS)], with 8 replicates in a completely randomized design. No differences (P > 0.05) among Se levels or sources were detected with regard to any performance parameters. The average values of ADFI, ADG, and FCR were 106 g/bird per day, 63 g/bird per day, and 1.684 kg/kg, respectively. No differences (P > 0.05) were found between treatments regarding pH (5.79) and shear force (30.08 kgf). Those birds receiving 0.15 ppm of Se showed a significantly higher (21.92%) cooking loss of breast meat (P < 0.05). The organic form of Se decreased cooking loss, and the smallest loss was found when the diet was supplemented with 0.60 ppm of Se (15.87%). Deposition of Se in the liver increased from 0.97 (0.15 ppm of Se) to 2.43 mg/kg (0.60 ppm of Se) when using SY. The concentration of Se in the breast meat increased linearly from 0.23 to 1.42 mg/kg with increasing dietary levels of SY. Therefore, dietary supplementation with 0.15 ppm of Se, independent of source, can maintain normal bird performance. The SY was more efficient in depositing Se to the liver and breast muscle than the SS.     

Effects of chelated Zn/Cu/Mn on redox status,immune responses and hoof health in lactating Holstein cows

To evaluate the effects of chelated Zn/Cu/Mn on redox status, immune responses and hoof health in lactating Holstein cows, 48 head in early lactation were divided into healthy or lame groups according to their gait score. Cows were fed the same amount of Zn/Cu/Mn as sulfate salts or in chelated forms for 180 days, and foot-and-mouth disease (FMD) vaccine was injected at day 90. The results showed that lame cows had lower antioxidant function, serum Zn/Mn levels, hair Cu levels, and hoof hardness. Moreover, increased antioxidant status, FMD antibody titers, serum and hair levels of Zn/Cu/Mn, and hoof hardness and decreased milk fat percent and arthritis biomarkers were observed in cows fed chelated Zn/Cu/Mn. In summary, supplementation with chelated Zn/Cu/Mn improved antioxidant status and immune responses, reduced arthritis biomarkers, and increased accumulation of Zn/Cu/Mn in the body and hoof hardness in dairy cows.     

饲粮减少矿物元素对育肥猪生长性能、肉品质、血清生化指标以及骨骼肌矿物元素含量的影响

本试验旨在研究饲粮中减少铁、锰、锌、镁和铜5种矿物元素添加量对育肥猪后期生长性能、肉品质、血清生化指标以及骨骼肌矿物元素含量的影响。选用体况良好、体重接近[(76.17±1.58)kg]的"杜×长×大"三元杂交育肥猪300头,随机分成3个组,每组10个重复,每个重复10头猪,公母各占1/2。对照组饲喂基础饲粮,试验组饲喂在基础饲粮基础上减少30%或60%矿物元素的饲粮。预试期3 d,正试期30 d。结果表明:与对照组相比,1)饲粮减少30%和60%矿物元素对育肥猪的生长性能和肉品质无显著影响(P0.05);2)饲粮减少30%和60%矿物元素,育肥猪血清氨含量显著升高(P0.05);减少60%矿物元素显著降低血清中总胆固醇的含量(P0.05),同时有降低血清总蛋白含量的趋势(P0.10);3)饲粮减少30%矿物元素对育肥猪骨骼肌中各矿物元素含量并无显著影响(P0.05),而减少60%矿物元素使得骨骼肌铜、铁和锰元素含量显著降低(P0.05)。由此得知,育肥猪饲粮中铁、锰、锌、镁和铜元素的含量可减少NRC(2012)推荐量的30%,而不会影响育肥猪后期的生长性能和肉品质。     

Effect of bis-glycinate bound zinc or zinc sulfate on zinc metabolism in growing lambs

To assess the efficacy of bis-glycinate bound Zn, 36 crossbred wethers (34 ± 2 kg) were sorted by body weight into three groups and stagger started on a Zn-deficient diet (18 mg Zn/kg dry matter [DM]; 22.5% neutral detergent fiber [NDF]) for 45 d prior to a 15-d metabolism period (10 d adaptation and 5 d collection). On day 46, lambs were randomly assigned to dietary treatments (four lambs treatment⁻¹group⁻¹): no supplemental Zn (CON) or 15 mg supplemental Zn/kg DM (ZINC) as Zn sulfate (ZS) or bis-glycinate (GLY; Plexomin Zn, Phytobiotics). Blood was collected from all lambs on days 1, 44, 56, and 61. Liver, jejunum, and longissimus dorsi samples were collected after euthanasia on day 61. Gene expression was determined via quantitative real-time polymerase chain reaction. Data were analyzed using ProcMixed of SAS (experimental unit = lamb; fixed effects = treatment, group, and breed) and contrast statements assessed the effects of supplemental Zn concentration (ZINC vs. CON) and source (GLY vs. ZS). After 15 d of Zn supplementation, plasma Zn concentrations were greater for ZINC vs. CON and GLY vs. ZS (P ≤ 0.01); tissue Zn concentrations were unaffected (P ≥ 0.27). Liver Cu concentrations were lesser for ZINC vs. CON (P = 0.03). Longissimus dorsi Mn concentrations were greater for ZINC vs. CON (P = 0.05) and tended to be lesser for GLY vs. ZS (P = 0.09). Digestibility of DM, organic matter (OM), and NDF was lesser for ZINC vs. CON (P ≤ 0.05); acid detergent fiber digestibility tended to be greater for GLY vs. ZS (P = 0.06). Nitrogen retention (g/d) tended to be greater for GLY vs. ZS (P = 0.10), and N apparent absorption was lesser for ZINC vs. CON (P = 0.02). Zinc intake, fecal output, retention, and apparent absorption were greater for ZINC vs. CON (P ≤ 0.01). Apparent absorption of Zn was −5.1%, 12.8%, and 15.0% for CON, ZS, and GLY, respectively. Nitrogen and Zn retention and apparent absorption were not correlated for CON (P ≥ 0.14) but were positively correlated for ZINC (retention: P = 0.02, r = 0.52; apparent absorption: P < 0.01, r = 0.73). Intestinal expression of Zn transporter ZIP4 was lesser for ZINC vs. CON (P = 0.02). Liver expression of metallothionein-1 (MT1) tended to be greater for GLY vs. ZS (P = 0.07). Although Zn apparent absorption did not differ between sources (P = 0.71), differences in post-absorptive metabolism may be responsible for greater plasma Zn concentrations and liver MT1 expression for GLY-supplemented lambs, suggesting improved bioavailability of GLY relative to ZS.     

Effect of gender on breast and thigh turkey meat quality

1. The influence of gender on chemical composition, physicochemical parameters, fatty acid profile, amino acid and mineral composition of turkey breast and thigh meat was studied in order to assess nutrient requirements.

2. Chemical composition showed that only intramuscular fat in breast meat was significantly affected by gender (p < 0.05). The results showed a higher percentage of intramuscular fat in male samples, almost double the amount found in females (0.73% vs. 0.38%).

3.For meat colour parameters, only a* showed different results between sexes, with male samples (breast: p < 0.01; thigh: p < 0.001) having the highest values.

4. Fatty acid profiles showed that medium chain unsaturated fatty acids were the most abundant. The significant differences (p < 0.05) found in both breast and thigh muscle could be linked to a difference in metabolism between males and females.

5.There were higher levels of C16:1n-7 in females (breast: p < 0.001; thigh: p < 0.01) compared with male muscle sample (5.05 vs. 2.67 g/100 g in breast and 4.95 vs. 3.27 g/100 g in thigh). Nutritional indices (n-6/n-3 and thrombogenic index) were more favourable in female samples demonstrating that female turkeys had better fatty acid profile than the others.

6. Turkey meat is an important source of dietary amino acids, and female samples had the highest contents both of essential and non-essential amino acids. Furthermore, gender had a numeric effect (p > 0.05) on amino acid composition.

7. Mineral composition showed that Na, Zn and Fe were the minerals most affected by turkey gender.     

Relative bioavailability of organic bis-glycinate bound copper relative to inorganic copper sulfate in beef steers fed a high antagonist growing diet

To assess the relative bioavailability of bis-glycinate bound Cu, 90 Angus-cross steers (265 ± 21 kg) were blocked by body weight (BW) to pens with GrowSafe bunks and randomly assigned to dietary treatments (14 to 18 steers/treatment): 0 mg supplemental Cu/kg dry matter (DM; CON), 5 or 10 mg supplemental Cu/kg DM as Cu sulfate (CS5; CS10) or bis-glycinate bound Cu (GLY5; GLY10). Steers received a high antagonist growing diet (analyzed 4.9 mg Cu/kg DM, 0.48% S, and 5.3 mg Mo/kg DM). Steers were weighed at the beginning (days 1 and 0) and end (days 125 and 126) of the trial to determine average daily gain (ADG) and gain:feed (G:F). Blood was collected from all steers on days 0, 28, 56, 84, and 126. Liver samples were collected on days −3 or −2 and day 123 or 124. Data were analyzed using ProcMixed of SAS (experimental unit = steer; fixed effect = treatment and block). Plasma Cu was analyzed as repeated measures (repeated effect = day). Plasma and liver Cu concentrations were regressed against total Cu intake using ProcGLM to calculate relative bioavailability of GLY. Final BW and overall ADG were greatest for CS5 and CS10 and least for CON and GLY5 (P = 0.01). Overall, DMI was not affected by treatment (P = 0.14), but overall G:F tended to be greatest for CS5, CS10, and GLY5 and least for CON (P = 0.08). Total and supplemental Cu intake was greatest for steers supplemented either source at 10 mg Cu/kg DM and least for CON (P < 0.01). However, total and supplemental Cu intake was greater for CS5 than GLY5 (P < 0.01). Final liver Cu concentrations were greatest for CS10, least for CON, CS5, and CS10, and intermediate for GLY10 (P < 0.01). Final plasma Cu was greatest for steers supplemented either source at 10 mg Cu/kg DM (P < 0.01). Relative bioavailability of GLY was 82% compared to CS based on liver Cu (P < 0.01) but did not differ based on plasma Cu (P = 0.60). The lesser bioavailability of GLY relative to CS could be due to a high concentration of dietary antagonists and lower solubility of GLY (68.9% relative to CS) in pH conditions (5.2) similar to the ruminal pH of a beef animal consuming a high concentrate diet. Future studies should examine the effects of bis-glycinate bound Cu fed in blended combination with inorganic Cu sulfate to determine the most effective blend of sources for feedlot cattle experiencing varying amounts of dietary Cu antagonists.     

Metabolic Challenges and Early Bone Development

Lameness is the phenotypic expression of a wide variety of genetic, conformational, nutritional, toxic, and infectious conditions. Poultry selected for rapid growth are susceptible to lameness, and it can be a significant source of mortality in heavy birds. Genetic selection has been successful in providing annual improvements in meat poultry productivity; however, some support systems, such as the cardiovascular and skeletal systems, have not kept up with the increase in body mass, making birds increasingly susceptible to compromise or failure of these systems. Breeders have been selecting for robust support systems in addition to increased productivity, but meat birds are still challenged with keeping structural and supply organs synchronized with the growth of demand tissues such as muscle. The structural system of the bird is comprised of bone, cartilage, ligaments, tendons, and the connective tissue of skin and other organs. Healthy bone growth can be disrupted by developmental, nutritional, environmental, or infectious conditions, with bone problems often being associated with more than one of these causes. A review of recent reports on bone formation and the role of trace minerals in bone development and repair indicate that availability of Zn, Cu, and Mn should be considered by nutritionists who want to enhance the resilience of bone, cartilage, and other structural tissues in their birds.     

Effects of two zinc supplementation levels and two zinc and copper sources with different solubility characteristics on the growth performance,carcass characteristics and digestibility of growing-finishing pigs

The present study was conducted to evaluate the effect of two Zn supplemented levels and two Zn and Cu sources (sulphate and hydroxychloride) on growing-finishing pigs. An in vitro study and an in vivo study were conducted. In the in vitro study, Zn solubility from each source at different Zn supplementation levels was evaluated, as well as the phytic phosphorus (PP) solubility derived from the interaction or not with phytic acid at similar conditions to those found in digestive tract. The most critical interaction of Zn with phytic acid was at pH 6.5 and with Zn sulphate, resulting in the reduction in PP solubility. In the in vivo experiment, a total of 444 pigs ([Duroc × Landrace]×Pietrain; initial BW: 18.7 ± 0.20 kg) were allotted to 36 pens in a randomized complete block design (2 × 2) factorial arrangement with two Zn and Cu sources and two Zn supplemental levels (20 and 80 mg/kg). The Cu supplementation was fixed at 15 mg/kg for all diets. There was no effect of the interaction between mineral source × Zn level or Zn level on growth performance or carcass characteristics (p > .10). Apparent total digestibility of Zn and Cu along with carcass yield was higher for pigs fed hydroxychloride than pigs fed the sulphate counterparts (p < .05). Feeding low levels of Zn decreased Zn (45.5%; p < .0001) and Cu(18.5%; p = .018) faecal excretion. In conclusion, under commercial conditions, feeding growing-finishing pigs with Zn levels below those established by the European Union regulation did not affect growth performance and carcass characteristics. Reducing dietary mineral (Zn and Cu) diet content resulted in a lower faecal mineral excretion. Pigs fed sulphate minerals had an improved performance during grower period, while pigs fed hydroxychloride minerals showed an improved performance during finishing period and a greater carcass yield and mineral digestibility than those fed sulphates.     

Antibiotic-resistant Escherichia coli isolated from chilled meat at retail outlets

Antibiotic resistance was investigated in Escherichia coli isolated from beef, veal, lamb and pork at retail level. A total of 100 samples from each meat species was examined. About 16% of the 400 samples were contaminated with resistant E.coli. Significantly more E.coli isolates from pork were drug-resistant than isolates from other meats(P<0.01). About 7% of the combined beef, veal, and lamb E.coli isolates were resistant to two or more antibiotics compared to about 40.0% of the pork isolates (P<0.01) Transfer of resistance was observed for 39.2% of multiple resistant isolates. The results presented form a base for future monitoring of the presence of antibiotic-resistant coliforms on meat suitable for human consumption.