Influence of dietary canola oil and palm oil blend and refrigerated storage on fatty acids,myofibrillar proteins,chemical composition,antioxidant profile and quality attributes of semimembranosus muscle in goats

Background: Improving the unsaturated fatty acid content of ruminant meat is essential due to the generally saturated nature of fatty acids in ruminant meat and the negative effects this can have on human health. Nonetheless, enhancing the unsaturated fatty acid content of ruminant meat can have adverse effects on the shelf life and quality attributes of the meat. This study assessed the effects of dietary 80 % canola oil and 20 % palm oil blend(CPOB) on fatty acid composition, antioxidants, oxidative spoilage, cholesterol and physicochemical properties of semimembranosus(SM)muscle from goats. Twenty four Boer bucks were randomly assigned to diets containing on dry matter basis 0, 4 and8 % CPOB, fed for 100 d and slaughtered. The carcasses were subjected to a 7 d postmortem refrigerated storage. Al analyses were conducted on the SM muscle.Results: Diet had no effect(P 0.05) on the concentration of free thiol and carbonyl and the band intensity of myosin heavy chain, actin and troponin T. The muscle glycogen, p H, water holding capacity, tenderness, glutathione peroxidase(GPX) activity, total carotenoid, δ-tocopherol, cholesterol and proximate composition did not differ(P 0.05) between diets. The SM muscle from goats fed 4 and 8 % CPOB had lower(P 0.05) concentration of C14:0 and C16:0 and higher(P 0.05) concentration of C18:1 trans-11, C18:1ω-9, C18:3ω-3, C20:5ω-3 and C22:5ω-3 than the SM muscle from the control goats. Dietary CPOB increased(P 0.05) the concentration of α and γ tocopherol and meat redness(a*) on d1 and 4 postmortem. Regardless of diet, antioxidant vitamins, and shear force decreased(P 0.05) while drip loss, lipid and protein oxidation increased(P 0.05) as postmortem storage progressed.Conclusion: Results evince that dietary CPOB can be used as a management tool to enhance the beneficial fatty acids and antioxidant contents of chevon without deleterious effects on its physicochemical properties and shelf life.     

Effects of melatonin implantation on carcass characteristics,meat quality and tissue levels of melatonin and prolactin in Inner Mongolian cashmere goats

Background: Implantation of goats with melatonin can induce cashmere growth and significantly increase cashmere production performance. However, the impact of melatonin implantation on the carcass characteristics,meat quality and related hormone levels in muscle and viscera of cashmere goats has not been studied. This experiment was conducted to determine the effects of melatonin implantation of cashmere goats during the nongrowing period on meat quality and related hormone levels in the tissues. It aimed to provide a theoretical basis for the practical application of melatonin in cashmere goat production systems.Results: Melatonin implantation(2 mg/kg live weight) had no influence(P 0.05) on daily weight gain, carcass weight, dressing percentage, loin muscle area, or the p H, moisture level, crude fat(except for Gluteus muscle) and amino acid content of muscles of cashmere goats. After implantation for 1 month, shear force of Longissimus dorsi and water loss rate of Longissimus dorsi and Biceps femoris of cashmere goats were increased(P 0.05), whereas the cooking yield of Gluteus muscle was reduced(P 0.05). The melatonin treatment decreased(P 0.05) muscle crude protein, Gluteus muscle crude fat and ∑n-3 PUFA content and decreased(P 0.05) ∑n-6 PUFA content.However, after 2 months of implantation most of these effects had resolved. Melatonin implantation had no effect(P 0.05) on the melatonin or prolactin contents of kidney, heart, spleen, liver, Longissimus dorsi, Biceps femoris and Gluteus muscles. Melatonin content of lung tissue was lowered(P 0.05) and that of prolactin was elevated(P 0.05) by the melatonin implantation.Conclusion: This study has shown little impact of melatonin implantation of cashmere goats on carcass quality. A few meat quality indices i.e., shear force, water loss rate, ∑n-3 PUFA, ∑n-6 PUFA, and crude protein content of Longissimus dorsi;water loss rate, cooking yield and crude protein content of Biceps femoris; ether extract, crude protein content of Gluteus;were affected briefly(at 1 month of implantation) but these effects were not evident after 2 months of implantation.There was little effect of the melatonin treatments on tissue levels of melatonin or prolactin except in lung.     

Effects of Compound Plant Nutrients on Rumen Fermentation Parameters,Rumen Microbiota and Fatty Acid Composition of Longissimus dorsi Muscle in Finishing Small Tail Han Sheep北大核心CSCD

This study was conducted to investigate the effects of compound p1ant nutrients (CPN) on rumen fermentation parameters, rumen microbiota and fatty acid composition of longissimus dorsi musc1e in finishing sma11 tai1 Han sheep. Sixteen 4-month-o1d finishing sma11 tai1 Han sheep with an initia1 body weight (BW) of (24.18±0.31) kg were random1y divided into two groups, name1y, with 8 rep1icates per group and 1 sheep per rep1icate. The sheep in the contro1 group were fed a basa1 diet, whereas the sheep of the contro1 group (CPN group) was fed the basa1 diet supp1ementation with 3‰ CPN. The experiment 1asted for 97 days after 7 days adaption. The resu1ts showed as fo11ows: compared with the contro1 group, 1) adding CPN decreased the concentration of ammonia nitrogen (NH3-N) (P<0.05); 2) CPN supp1ementation affected beta diversity of rumen microbiota; 3) the re1ative abundance of Acidobacteriota, Erysipe1otrichaceae_UCG-002, Lactobacillus, and Megasphaera were enhanced by adding CPN (P<0.05), whereas, the re1ative abundance of Bacteroidetes and Prevotella was 1ower (P<0.05); 4) the supp1ementation of CPN had no significant effect on fatty acid composition of longissimus dorsi musc1e of fattening sma11-tai1ed Han sheep (P>0.05); 5) the contents of tota1 MUFA, C18:1n9c, C14:1, C16:1, C18:2n6c, C18:3n3 and n-3PUFA in the longissimus dorsi musc1e were corre1ated with the re1ative abundance of Megasphaera, Erysipe1otrichaceae_UCG-002, Succiniclasticum and Ruminococcus (P<0.05). In conc1usion, CPN can regu1ate the rumen microbiota structure and reduce the rumen NH3-N concentration of fattening sma11-tai1ed Han sheep. In production practice, CPN can be used as a rumen eco1ogica1 regu1ator. © 2023 Authors. All rights reserved.     

Betaine affects muscle lipid metabolism via regulating the fatty acid uptake and oxidation in finishing pig

Background: Betaine affects fat metabolism in animals, but the specific mechanism is still not clear. The purpose of this study was to investigate possible mechanisms of betaine in altering lipid metabolism in muscle tissue in finishing pigs.Methods: A total of 120 crossbred gilts(Landrace × Yorkshire × Duroc) with an average initial body weight of 70.1 kg were randomly allotted to three dietary treatments. The treatments included a corn–soybean meal basal diet supplemented with 0, 1250 or 2500 mg/kg betaine. The feeding experiment lasted 42 d.Results: Betaine addition to the diet significantly increased the concentration of free fatty acids(FFA) in muscle(P 0.05). Furthermore, the levels of serum cholesterol and high-density lipoprotein cholesterol were decreased(P 0.05) and total cholesterol content was increased in muscle(P 0.05) of betaine fed pigs. Experiments on genes involved in fatty acid transport showed that betaine increased expression of lipoprotein lipase(LPL), fatty acid translocase/cluster of differentiation(FAT/CD36), fatty acid binding protein(FABP3) and fatty acid transport protein(FATP1)(P 0.05). The abundance of fatty acid transport protein and fatty acid binding protein were also increased by betaine(P 0.05). As for the key factors involved in fatty acid oxidation, although betaine supplementation didn't affect the level of carnitine and malonyl-CoA, betaine increased mR NA and protein abundance of carnitine palmitransferase-1(CPT1)and phosphorylated-AMPK(P 0.05).Conclusions: The results suggested that betaine may promoted muscle fatty acid uptake via up-regulating the genes related to fatty acid transporter including FAT/CD36, FATP1 and FABP3. On the other hand, betaine activated AMPK and up-regulated genes related to fatty acid oxidation including PPARα and CPT1. The underlying mechanism regulating fatty acid metabolism in pigs supplemented with betaine is associated with the up-regulation of genes involved in fatty acid transport and fatty acid oxidation.     

Different dietary starch sources alter the carcass traits,meat quality,and the profile of muscle amino acid and fatty acid in finishing pigs

Background: With increasing health awareness among consumers, the demand for healthier, tastier, higher quality and nutritional value pork is increasing. It has been shown that different dietary starch sources can alter the carcass traits and meat quality. However, research on the effects of different starch sources with clear different amylose/amylopectin ratio on the amino acid and fatty acid composition in Longissimus thoracis(L. thoracis) muscle of pigs is limited. This study aimed to investigate the effects of different dietary starch sources on carcass traits, meat quality, muscle amino acid and fatty acid composition, and the mRNA expression levels of genes involved in lipid metabolism and muscle fiber characteristics in finishing pigs. A total of 72 Duroc × Landrace × Large White barrows were randomly allocated to 3 different dietary treatment groups with 8 replicate pens/group and 3 pigs per pen.Tapioca starch(TS), corn starch(CS), and pea starch(PS), with amylose/amylopectin ratio of 0.11, 0.25, and 0.44,respectively, were used as their dietary starch sources for 40 days.Results: Results showed that the PS diet significantly increased(P < 0.05) the final body weight, average daily gain,loin-eye area, and fat-free lean index compared with the TS diet, but significantly decreased(P < 0.05) the feed to gain ratio and backfat thickness. Compared with the TS diet, PS diet also increased(P < 0.05) the pH45 min, marbling scores, the content of intramuscular fat and inosine monophosphate in the L. thoracis, and decreased(P < 0.05) the drip loss and shear force. In addition, compared with the TS diet, PS diet increased(P < 0.05) the proportions of flavor amino acids, DHA, EPA, and n-3 polyunsaturated fatty acid(PUFA) in the L. thoracis compared with TS diet,but decreased(P < 0.05) the ratio of n-6/n-3 PUFA. Furthermore, compared with the TS diet, PS diet also upregulated(P < 0.05) the lipogenic genes(FAS, LPL, SCD, ACCα) and myosin heavy-chain(MyHC)-IIa mRNA expression levels compared with the TS diet, but downregulated(P < 0.05) the CPT1 B and MyHC-IIb mRNA levels.Conclusions: In conclusion, these results provided compelling evidence that the different dietary starch source altered the carcass traits, meat flavor and quality in finishing pigs, and consumption of a diet with higher amylose/amylopectin ratio results in the production of a healthy, higher quality, and nutritional value pork.     

Dose and time response of ruminally infused algae on rumen fermentation characteristics,biohydrogenation and Butyrivibrio group bacteria in goats

Background: Micro-algae could inhibit the complete rumen BH of dietary 18-carbon unsaturated fatty acid(UFAs).This study aimed to examine dose and time responses of algae supplementation on rumen fermentation,biohydrogenation and Butyrivibrio group bacteria in goats.Methods: Six goats were used in a repeated 3 × 3 Latin square design, and offered a fixed diet. Algae were infused through rumen cannule with 0(Control), 6.1(L-Alg), or 18.3 g(H-Alg) per day. Rumen contents were sampled on d 0, 3, 7, 14 and 20.Results: H-Alg reduced total volatile fatty acid concentration and acetate molar proportion(P 0.05), and increased propionate molar proportion(P 0.05), whereas L-Alg had no effect on rumen fermentation.Changes in proportions of acetate and propionate in H-Alg were obvious from d 7 onwards and reached the largest differences with the control on d 14. Algae induced a dose-dependent decrease in 18:0 and increased trans-18:1 in the ruminal content(P 0.05). H-Alg increased the concentrations of t9, t11-18:2 and t11,c15-18:2(P 0.05). L-Alg only seemed to induce a transient change in 18-carbon isomers, while H-Alg induced a rapid elevation, already obvious on d 3, concentrations of these fatty acid rose in some cases again on d 20. Algae had no effect on the abundances of Butyrivibrio spp. and Butyrivibrio proteoclasticus(P 0.10), while H-Alg reduced the total bacteria abundance(P 0.05). However, this was induced by a significant difference between control and H-Alg on d14(-4.43 %). Afterwards, both treatments did not differ as increased variation in the H-Alg repetitions, with in some cases a return of the bacterial abundance to the basal level(d 0).Conclusions: Changes in rumen fermentation and 18-carbon UFAs metabolism in response to algae were related to the supplementation level, but there was no evidence of shift in ruminal biohydrogenation pathways towards t10-18:1.L-Alg mainly induced a transient effect on rumen biohydrogenation of 18-carbon UFAs, while H-Alg showed an acute inhibition and these effects were not associated with the known hydrogenating bacteria.     

Dietary calcium supplementation promotes the accumulation of intramuscular fat

Background:In the livestock industry,intramuscular fat content is a key factor affecting meat quality.Many studies have shown that dietary calcium supplementation is closely related to lipid metabolism.However,few studies have examined the relationship between dietary calcium supplementation and intramuscular fat accumulation.Methods:Here,we used C2C12 cells,C57BL/6 mice(n=8)and three-way cross-breeding pigs(Duroc×Landrace×Large white)(n=10)to study the effect of calcium addition on intramuscular fat accumulation.In vitro,we used calcium chloride to adjust the calcium levels in the medium(2 mmol/L or 3 mmol/L).Then we measured various indicators.In vivo,calcium carbonate was used to regulate calcium levels in feeds(Mice:0.5%calcium or 1.2%calcium)(Pigs:0.9%calcium or 1.5%calcium).Then we tested the mice gastrocnemius muscle triglyceride content,pig longissimus dorsi muscle meat quality and lipidomics.Results:In vitro,calcium addition(3 mmol/L)had no significant effect on cell proliferation,but promoted the differentiation of C2C12 cells into slow-twitch fibers.Calcium supplementation increased triglyceride accumulation in C2C12 cells.Calcium addition increased the number of mitochondria and also increased the calcium level in the mitochondria and reduced the of key enzymes activity involved inβ-oxidation such as acyl-coenzyme A dehydrogenase.Decreasing mitochondrial calcium level can alleviate lipid accumulation induced by calcium addition.In addition,calcium addition also reduced the glycolytic capacity and glycolytic conversion rate of C2C12 cells.In vivo,dietary calcium supplementation(1.2%)promoted the accumulation of triglycerides in the gastrocnemius muscle of mice.Dietary calcium supplementation(1.5%)had no effect on pig weight,but significantly improved the flesh color of the longissimus dorsi muscle,reduced the backfat thickness and increased intramuscular fat content in pigs.Besides,calcium addition had no effect on longissimus dorsi pH,electrical conductivity and shear force.Conclusions:These results suggest that calcium addition promotes intramuscular fat accumulation by inhibiting the oxidation of fatty acids.These findings provide a new tool for increasing intramuscular fat content and an economical strategy for improving meat quality.     

Effects of Chrysanthemum coronarium Extract on Fermentation Characteristics and Biohydrogenation of Polyunsaturated Fatty Acids in vitro Batch Culture

IntroductionCis-9,trans-11 CLA has been shown to be potentially healthpromoting CLA in many animal models.The C18∶1 trans-11 fatty acid (VA) is also desirable as a product flowing from the rumen,because the flow from the rumen of VA play a more important role than CLA in determining CLA concentration in animal tissues.The factors which affect CLA content in milk have been studied mainly in dairy cows and most factors are basically dietary factors,especially fat source(e.g.,plant oils,fish oil,et al.).Recently some researches showed that some plants or plant extracts could increase cis-9,trans-11 -CLA content in milk.The purpose of this experiment was to evaluate the effects of Chrysanthemum coronarium extract on in vitro Biohydrogenation of polyunsaturated fatty acids and fermentation characteristics of mixed rumen microorganisms.     

Egg quality,fatty acid composition and immunoglobulin Y content in eggs from laying hens fed full fat camelina or flax seed

Background: The current study was conducted to evaluate egg quality and egg yolk fatty acids and immunoglobulin(Ig Y) content from laying hens fed full fat camelina or flax seed.Methods: A total of 75, 48-week-old Lohman brown hens were randomly allocated to 3 treatments, with 5replicates containing 5 laying hens each replicate. The hens were fed corn-soybean basal diet(Control), or Control diet with 10 % of full fat camelina(Camelina) or flax seed(Flax) for a period of 16 wk. Hen production performance egg quality, egg yolk lipids, fatty acids and Ig Y were determined every 28 d during the experimental period.Results: Egg production was higher in hens fed Camelina and Flax than in Control hens(P 0.05). Egg weight and albumen weight was lowest in eggs from hens fed Camelina(P 0.05). Shell weight relative to egg weight(shell weight %), and shell thickness was lowest in eggs from hens fed Flax(P 0.05). No difference was noted in Haugh unit, yolk:albumen ratio, and yolk weight. Significant increase in α-linolenic(18:3 n-3), docosapentaenoic(22:5 n-3)and docoshexaenoic(22:6 n-3) acids were observed in egg yolk from hens fed Camelina and Flax. Total n-3 fatty acids constituted 1.19 % in Control eggs compared to 3.12 and 3.09 % in Camelina and Flax eggs, respectively(P 0.05). Eggs from hens fed Camelina and Flax had the higher Ig Y concentration than those hens fed Control diet when expressed on a mg/g of yolk basis(P 0.05). Although the egg weight was significantly lower in Camelina-fed hens, the total egg content of Ig Y was highest in eggs from hens fed Camelina(P 0.05).Conclusions: The egg n-3 fatty acid and Ig Y enhancing effect of dietary camelina seed warrants further attention into the potential of using camelina as a functional feed ingredient in poultry feeding.     

Dietary arachidonate in milk replacer triggers dual benefits of PGE_2 signaling in LPS-challenged piglet alveolar macrophages

Background: Respiratory infections challenge the swine industry, despite common medicinal practices. The dual signaling nature of PGE_2(supporting both inflammation and resolution) makes it a potent regulator of immune cell function. Therefore, the use of dietary long chain n-6 PUFA to enhance PGE_2 effects merits investigation.Methods: Day-old pigs(n = 60) were allotted to one of three dietary groups for 21 d(n = 20/diet), and received either a control diet(CON, arachidonate = 0.5% of total fatty acids), an arachidonate(ARA)-enriched diet(LC n-6,ARA = 2.2%), or an eicosapentaenoic(EPA)-enriched diet(LC n-3, EPA = 3.0%). Alveolar macrophages and lung parenchymal tissue were collected for fatty acid analysis. Isolated alveolar macrophages were stimulated with LPS in situ for 24 h, and m RNA was isolated to assess markers associated with inflammation and eicosanoid production.Culture media were collected to assess PGE_2 secretion. Oxidative burst in macrophages was measured by: 1)oxygen consumption and extracellular acidification(via Seahorse), 2) cytoplasmic oxidation and 3) nitric oxide production following 4, 18, and 24 h of LPS stimulation.Results: Concentration of ARA(% of fatty acids, w/w) in macrophages from pigs fed LC n-6 was 86% higher than CON and 18% lower in pigs fed LC n-3(P 0.01). Following LPS stimulation, abundance of COX-2 and TNF-α mRNA(P 0.0001), and PGE_2 secretion(P 0. 01) were higher in LC n-6 PAM vs. CON. However, ALOX5 abundance was1.6-fold lower than CON. Macrophages from CON and LC n-6 groups were 4-fold higher in ALOX12/15 abundance(P 0.0001) compared to LC n-3. Oxygen consumption and extracellular acidification rates increased over 4 h following LPS stimulation(P 0.05) regardless of treatment. Similarly, increases in cytoplasmic oxidation(P 0.001)and nitric oxide production(P 0.002) were observed after 18 h of LPS stimulation but were unaffected by diet.Conclusions: We infer that enriching diets with arachidonic acid may be an effective means to enhance a stronger innate immunologic response to respiratory challenges in neonatal pigs. However, further work is needed to examine long-term safety, clinical efficacy and economic viability.     

Effects of Artemisia annua Extracts on Ruminal Fermentation Parameters in vivo,Concentration of Conjugated Linoleic Acid in the Rumen and Milk in Dairy Goats

IntroductionIt has been well established that plant oil or fish oil could enhance cis-9 trans-11CLA content in the ruminant food products.However, it is generally accepted that adding unsaturated fatty acid to ruminant diets may exert negative effects on fiber degradation and rumen microbe populations.For this reason,there is growing interest in evaluating the potential measures of increasing cis-9 trans-11CLA content in the ruminant food products.Recently some researches showed that some plants or plant extracts could increase cis-9 trans-11CLA content in milk.The objective of this experiment was to evaluate the effects of Artemisia annua Extracts (AAE) on ruminal fermentation parameters in vivo,the proportions of cis-9 trans11CLA and trans-11 C18∶1 in the ruminal fluid and in dairy goats milk.     

Poultry fat decreased fatty acid transporter protein mRNA expression and affected fatty acid composition in chickens

Background: A study was undertaken to examine the effects of poultry fat (PF) compared with those of soybean oil (SBO) on intestinal development, fatty acid transporter protein (FATP) mRNA expression, and fatty acid composition in broiler chickens. A total of 144 day-old male commercial broilers were randomly allocated to 2 treatment groups (6 replicates of 12 chicks for each treatment) and fed isocaloric diets containing 3.0% PF or 2.7% SBO at 0 to 3 wk and 3.8% PF or 3.5% SBO at 4 to 6 wk, respectively. Results: PF had no influence on intestinal morphology, weight, or DNA, RNA, or protein concentrations at 2, 4, and 6 wk of age. However, compared with SBO, PF significantly decreased FATP mRNA abundance at 4 wk (P=0.009) and 6 wk of age (P<0.001); decreased liver fatty acid-binding protein (L-FABP) mRNA abundance at 6 wk of age (P=0.039); and decreased C18:2 (P=0.015), C18:3 (P<0.001), C20:2 (P=0.018), Σ-polyunsaturated fatty acids (Σ-PUFA) (P = 0.020), and the proportion of PUFA (P<0.001) in the intestinal mucosa and decreased C18:2 (P=0.010), C18:3 (P<0.001), C20:2 (P<0.001), Σ-PUFA (P=0.005), and the proportion of PUFA (P<0.001) in breast muscle at 6 wk of age. Conclusions: PF decreases FATP and L-FABP mRNA expression and decreased the proportion of PUFA in the intestinal mucosa and breast muscle.     

Effects of dietary concentrate level and chromium-methionine supplementation on ruminal fermentation,and ruminal bacterial and fatty acid composition in Tan lambs北大核心CSCD

This study evaluated the effects of dietary concentrate level and chromium methionine(Cr-Met)supplementation on ruminal fermentation and fatty acid composition, and ruminal bacteria abundance in Tan lambs. Forty male Tan lambs [(21.00±1.23) kg body weight, 5 months of age] were randomly assigned to four treatment groups with 10 lambs in each treatment. The treatments were: a low-concentrate (LC) diet (concentrate:forage, 35:65) without Cr-Met supplementation; a high-concentrate (HC) diet (concentrate:forage, 55:45) without Cr-Met supplementation; groups fed the HC diet with 0.75 or 1.50 g·d-1·lamb-1 Cr-Met (HCM and HCH, respectively). Ruminal fluid was collected on day 65 with an oral stomach tube about 3 h after the morning feed and samples used for fermentation analysis, fatty acid composition determination and bacterial DNA extraction. It was found that: 1) Ruminal pH, acetate proportion and acetate:propionate were greater (P<0.05) with the LC diet whereas microbial crude protein, propionate and valerate proportions were greater (P<0.05) with the HC diet. The acetate:propionate was greater (P<0.05) in the HCM group than in the HC group. 2) For the HC diet, the DNA abundances of Butyrivibrio fibrisolvens vaccenic acid subgroup (Butyrivibrio VA) and Ruminococcus flavefaciens were decreased (P<0.05), compared with the LC diet, whereas the DNA abundance of Anaerovibrio lipolytica was increased (P<0.05). For lambs fed the HC diet, DNA abundances of B. fibrisolvens stearic acid subgroup, Butyrivibrio VA, Butyrivibrio proteoclasticus, and A. lipolytica showed a linear decrease (P<0.05) with increasing Cr-Met supplementation level; However, the DNA abundance of R. flavefaciens showed a linear increase (P<0.05). 3) Compared with the LC group, the concentrations of t11 C18:1, trans C18:1, c9t11 CLA, t10c12 CLA, C18:2n6, and C18:3n3 were decreased by the HC diet without Cr-Met supplementation whereas the concentration of C18:0 was increased. There was a linear increase in t11 C18:1 and trans C18:1 with increasing Cr-Met supplementation level in lambs fed the HC diet. The results suggest that the HC diet inhibited the growth of ruminal bacteria involved in the ruminal biohydrogenation process, and the addition of Cr-Met had a potentially positive effect on conjugated linoleic acid (CLA) synthesis in body tissue. © 2022, Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

Fortification of pork loins with docosahexaenoic acid(DHA) and its effect on flavour

Pork is traditionally low in docosahexanoic acid(DHA, C22:6n-3) and deficient in omega-3 fats for a balanced human diet. DHA as triglycerides was commercially prepared from the microalgae Schizochytrium and injected into fresh pork loins. Treatments of a mixed brine control(CON), 3.1% sunflower oil in mixed brine(SF) and a 3.1% DHA oil in mixed brine(DHA) were injected into pork loins at 10 mL/100 g and grilled at 205°C. After cooking, the CON and SF pork loins contained 0.03 to 0.05 mg DHA/g of pork and the DHA injected loins contained approximately1.46 mg DHA/g. This also changed the fatty acid profile of omega-6: omega-3 from, 5 to 1 in the CON pork, to a ratio of 1.7 to 1 in DHA pork. The appearance, odor, oxidation rates and sensory taste, as judged by a trained panel,determined the DHA injected meat to be, ‘slightly desirable' and gave lower ‘off flavour' scores, relative to the CON and SF injected pork. Pork can be fortified with DHA oil to 146 mg/100 g serving, which would meet half the recommended daily omega 3 fatty acid requirements for adult humans and would be desirable in taste.     

Effects of ensiling processes and antioxidants on fatty acid concentrations and compositions in corn silages

Background： Corn silage is the main dietary component used for ruminant breeding in China and is an important dietary source of fatty acids for these animals. However, little is known regarding effective means to protect the fatty acid （FA） contents in silages. In this study, we examined the changes in FA contents and compositions during corn ensiling and screened several antioxidants for their inhibition of lipid oxidation during corn ensiling. Methods： We conducted two different experiments. In Experiment 1, corn was ensiled in 30 polyethylene bottles （bottle volume： 1 L, silage density： 600 g/dm3） and three bottles were opened at 0.5 d, 1 d, 1.5 d, 2 d, 2.5 d, 3 d, 5 d, 7 d, 14 d, and 28 d after ensiling. In Experiment 2, corn was treated with various antioxidants： （1） No additives （CK）; （2） BHA （Butylated hydroxyanisole）; （3） TBHQ （Tertiary butyl hydroquinone）; （4） TPP （Tea polyphenols）; and （5） VE （Vitamin E）. These treatments were applied at 50 mg/kg and 100 mg/kg of fresh weight with each treatment replicated 3 times. Results： During ensiling in Experiment 1, saturated fatty acids （SFA; C16：0 and C18：0） and malondialdehyde （MDA） contents tended to increase, whereas unsaturated fatty acids （UFA; C18：1, C18：2 and C1 8：3） tended to decrease. However, these changes were only significant on the first 2 days of ensiling. In Experiment 2, all of the antioxidants tested affected the total FA contents and those of unsaturated fatty acids （C1 8：1, C18：2 and C18：3） and MDA. The effects of TBHQ and TPP were greater than those of the other antioxidants. Conclusions; The reduced total FA contents in corn silages were due to unsaturated fatty acids＇ oxidation during the early stages of ensiling. Adding an antioxidant could prevent fattv acids＇ oxidation in corn silages.     

Effects of the dietary nonfiber carbohydrate content on lactation performance,rumen fermentation,and nitrogen utilization in mid-lactation dairy cows receiving corn stover

Background: Corn stover(CS) is an abundant source of feed for livestock in China. However, it is low in nutritional value that we have been seeking technologies to improve. Previous studies show that non-fiber carbohydrate(NFC)might limit the utilization of a CS diet by lactating dairy cows. Thus, this study was conducted to investigate the lactation performance and rumen fermentation characteristics in lactating cows consuming CS with two contents of NFC compared to an alfalfa hay-containing diet. Twelve Holstein cows were used in a replicated 3 × 3 Latin square design with three dietary treatments:(1) low-NFC diet(NFC = 35.6%, L-NFC),(2) high-NFC diet(NFC = 40.1%,H-NFC), and(3) alfalfa hay diet(NFC = 38.9%, AH).Results: Intake of DM was lower for cows fed H-NFC compared to L-NFC and AH, while the milk yield was higher in AH than in H-NFC and L-NFC(P 0.01). The feed efficiency(milk yield/DM intake, 1.15 vs. 1.08, P 0.01) were greater for cows fed H-NFC than L-NFC. The contents of milk protein and lactose were not different among the groups(P 0.11), but milk fat content was higher for cows fed H-NFC and L-NFC compared to AH(P 0.01). The rumen ammonia nitrogen concentration and the concentrations of urea nitrogen in blood and milk were lower for cows fed H-NFC and AH compared to L-NFC(P 0.05). The concentrations of rumen propionate and total volatile fatty acids were different among groups(P 0.05) with higher concentration for cows fed AH compared to H-NFC and L-NFC, and acetate concentration tended to be different among groups(P = 0.06).Conclusions: From the results obtained in this study, it was inferred that the increased NFC content in a diet containing corn stover can improve the feed efficiency and benefit the nitrogen conversion.     

Effects of Saccharomyces cerevisiae fermentation products on performance and rumen fermentation and microbiota in dairy cows fed a diet containing low quality forage

Background: A possible option to meet the increased demand of forage for dairy industry is to use the agricultural byproducts, such as corn stover. However, nutritional value of crop residues is low and we have been seeking technologies to improve the value. A feeding trial was performed to evaluate the effects of four levels of Saccharomyces cerevisiae fermentation product(SCFP; Original XP; Diamond V) on lactation performance and rumen fermentation in mid-lactation Holstein dairy cows fed a diet containing low-quality forage. Eighty dairy cows were randomly assigned into one of four treatments: basal diet supplemented with 0, 60, 120, or 180 g/d of SCFP per head mixed with 180, 120, 60, or 0 g of corn meal, respectively. The experiment lasted for 10 wks, with the first 2 weeks for adaptation.Results: Dry matter intake was found to be similar(P 0.05) among the treatments. There was an increasing trend in milk production(linear, P ≤ 0.10) with the increasing level of SCFP supplementation, with no effects on contents of milk components(P 0.05). Supplementation of SCFP linearly increased(P 0.05) the N conversion, without affecting rumen pH and ammonia-N(P 0.05). Increasing level of SCFP linearly increased(P 0.05) concentrations of ruminal total volatile fatty acids, acetate, propionate, and butyrate, with no difference in molar proportion of individual acids(P 0.05). The population of fungi and certain cel ulolytic bacteria(Ruminococcus albus, R. flavefaciens and Fibrobacter succinogenes)increased linearly(P 0.05) but those of lactate-utilizing(Selenomonas ruminantium and Megasphaera elsdeni) and lactate-producing bacteria(Streptococcus bovis) decreased linearly(P ≤ 0.01) with increasing level of SCFP. The urinary purine derivatives increased linearly(P 0.05) in response to SCFP supplementation, indicating that SCFP supplementation may benefit for microbial protein synthesis in the rumen.Conclusions: The SCFP supplementation was effective in maintaining milk persistency of mid-lactation cows receiving diets containing low-quality forage. The beneficial effect of SCFP could be attributed to improved rumen function; 1)microbial population shift toward greater rumen fermentation efficiency indicated by higher rumen fungi and cel ulolytic bacteria and lower lactate producing bacteria, and 2) rumen microbial fermentation toward greater supply of energy and protein indicated by greater ruminal VFA concentration and increased N conversion. Effects of SCFP were dose-depended and greater effects being observed with higher levels of supplementation and the effect was more noticeable during the high THI environment.