Replacing soybean meal with high-oil pumpkin seed cake in the diet of lactating Holstein dairy cows modulated rumen bacteria and milk fatty acid profile.

This research aimed to investigate the effects of replacing soybean meal with high-oil pumpkin seed cake (HOPSC) on ruminal fermentation, lactation performance, milk fatty acid, and ruminal bacterial community in Chinese dairy cows. Six multiparous Chinese Holstein cows at 105.50 ± 5.24 d in milk (mean ± standard deviation) and 36.63 ± 0.74 kg/d of milk yield were randomly allocated, in a 3 × 3 Latin square design, to 3 dietary treatments in which HOPSC replaced soybean meal. Group 1 was the basal diet with no HOPSC (0HOPSC); group 2 was a 50% replacement of soybean meal with HOPSC and dried distillers grains with solubles (DDGS; 50HOPSC), and group 3 was a 100% replacement of soybean meal with HOPSC and DDGS (100HOPSC). We found no difference in the quantity of milk produced or milk composition among the 3 treatment groups. Feed efficiency tended to increase linearly as more HOPSC was consumed. In addition, rumen fermentation was not influenced when soybean meal was replaced with HOPSC and DDGS; the relative abundance of ruminal bacteria at the phylum and genus levels was altered. We also observed that as the level of HOPSC supplementation increased, the relative abundance of Firmicutes and Tenericutes linearly increased, whereas that of Bacteroidetes decreased. However, with increasing HOPSC supplementation, the relative abundance of Ruminococcus decreased linearly at the genus level in the rumen, and the relative abundance of Prevotella showed a linear downward tendency. Changes in dietary composition and rumen bacteria had no significant effect on the fatty acid composition of milk. In conclusion, our results indicated that replacing soybean meal with a combination of HOPSC and DDGS can meet the nutritional needs of high-yielding dairy cows without adversely affecting milk yield and quality; however, the composition of rumen bacteria could be modified. Further study is required to investigate the effects of long-term feeding of HOPSC on rumen fermentation and performance of dairy cows.

Nutritional Values of Industrial Hemp Byproducts for Dairy Cattle.

The objective of this experiment was to explore the nutritional components of industrial hemp byproducts (industrial hemp ethanol extraction byproduct, IHEEB; industrial hemp stalk, IHS; industrial hemp seed meal, IHSM; industrial hemp oil filter residue, IHOFR) and provide theoretical support for the application of industrial hemp byproducts in dairy cattle production. This experiment used a combination of a wet chemical method with Cornell Net Carbohydrate and Protein System, in situ nylon bag technique, and three-step in vitro method to compare the chemical composition, carbohydrate and protein composition, in situ ruminal degradability and intestinal digestibility of industrial hemp byproducts and conventional feeds (alfalfa hay, AH; soybean meal, SBM). Available energy values were estimated based on the National Academies of Sciences, Engineering, and Medicine. The results showed that the nutritional composition of different feeds varied greatly. The two types of IHEEB were enriched with ash, crude protein (CP), neutral detergent fiber (NDF), and calcium, while the contents of neutral detergent insoluble crude protein, acid detergent insoluble crude protein, and acid detergent lignin were higher. As a result, the non-degradable carbohydrate and protein components were higher, and the effective degradation rate of rumen dry matter and protein was lower. IHS contains higher non-protein nitrogen and NDF, which enables it to provide more CP rumen effective degradation rate and carbohydrates, but the high acid detergent fiber also limits its application. IHSM possesses 296 g/kg CP and high rumen undegradable protein and intestinal digested protein, which can provide rumen bypass protein in dairy cows, making it a potentially good protein source. IHOFR had higher ether extract, rumen available protein degradation rate, and total tract digested protein, which can provide more energy and easily degradable protein for lactating cows. The available energy value of IHEEB and IHS was lower than AH, while SBM is between IHFOR and IHSM. In addition, the tetrahydrocannabinol of three industrial hemp byproducts that have not been assessed by the European Food Safety Authority (EFSA) was tested to evaluate their safety, and all of them were less than the limit set by ESFA. In conclusion, industrial hemp byproducts can be considered for inclusion in dietary formulations as unconventional feed sources for dairy cattle, but the purpose of use needs to be properly considered.

Effects of 1-methylcyclopropene (1-MCP) treatment on ethanol fermentation of Nanguo pear fruit during ripening.

The aim of this study was to analyze the effects of 1-methylcyclopropene (1-MCP) on ethanol fermentation of Nanguo pears during ripening. Pears were exposed to 1 µl/L 1-MCP and stored at 20 ± 2°C. Our data indicated that postharvest application of 1-MCP maintained flesh firmness and reduced ethylene production and respiration rate during storage compared with untreated fruits. 1-MCP treatment delayed the second glucose peak during fruit ripening. The contents of pyruvate and acetyl-CoA were generally reduced by 1-MCP treatment, and at the same time, their peaks were delayed by it during storage compared with controls. The contents of citric acid (CA) and oxaloacetate (OA) were increased by 1-MCP, whereas the contents of acetaldehyde and ethanol were reduced during the whole storage period compared with controls. Activities of alcohol dehydrogenase (ADH) and pyruvate decarboxylase (PDC) were reduced by application of 1-MCP during the early stage of storage, and the appearance of their peak activities was also delayed after treatment with 1-MCP. These data showed that postharvest application of 1-MCP could effectively delay the production of the "alcohol taste" of Nanguo pears during ripening. PRACTICAL APPLICATIONS: Nanguo pear is one of the most common cultivars that widely grow in northeast China. It is preferred by many consumers for its unique "alcohol taste", which is mainly produced through ethanol fermentation during ripening. Until now, the mechanisms for regulating ethanol fermentation in ripening Nanguo pears are still unclear. Our data indicated that postharvest application of the ethylene action inhibitor 1-MCP could effectively delay the production of the "alcohol taste" of Nanguo pears during ripening. The data from this study can provide reference data for maintaining the quality of postharvest Nanguo pears.

Effects of 1-MCP treatment on sprouting and preservation of ginger rhizomes during storage at room temperature.

The purpose of this study was to explore the effects of 1-MCP on the sprouting and preservation of ginger rhizomes during storage at room temperature. Ginger rhizomes were treated with 1 µL L-1 1-methylcyclopropene (1-MCP) and stored at 23 ± 0.2 °C. Our data showed that application of 1-MCP reduced the rate of sprouting during storage compared with the control rhizome. Respiration rate and the reducing sugar content were also reduced following 1-MCP treatment, while the starch content increased. 1-MCP treatment increased the total phenol content and inhibited polyphenol oxidase (PPO) activity. 1-MCP treatment was also associated with a higher ascorbic acid content but a reduced crude fiber content. The generation of superoxide anion free radicals (O2-), hydrogen peroxide (H2O2) and malondialdehyde (MDA) was lower following 1-MCP treatment, while the activities of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) were higher compared with the controls. These results suggested that application of 1-MCP could reduce sprouting rates, decrease the accumulation of ROS, and maintain the quality of ginger rhizomes during storage at room temperature. It would be useful to further explore the role and mechanisms of action of ethylene in regulating the sprouting of ginger rhizomes.

Postharvest acibenzolar-S-methyl treatment maintains storage quality and retards softening of apple fruit.

"Golden delicious" apples were dipped in 100 mg/L acibenzolar-S-methyl (ASM) to investigate the fruit quality and softening during 12 days of storage. Weight loss, flesh firmness, ethylene release, respiratory rate, content of total soluble solids and titratable acid, the activity of pectinase, cellulase, and ß-glucosidase, and water-insoluble pectin and water-soluble pectin contents were investigated. The results demonstrated that ASM treatment inhibited ethylene release and respiratory rate, reduced titratable acidity, and enhanced total soluble solids content in apples. Moreover, application of ASM suppressed the reduction of flesh firmness, activity of pectin methylesterase, and polygalacturonase. Cellulase, ß-glucosidase, and degradation of protopectin in apple fruit were also suppressed by ASM treatment during storage. In conclusion, ASM could maintain fruit quality by regulating cell wall-degrading enzymes during storage. PRACTICAL APPLICATIONS: Application of acibenzolar-S-methyl after harvest has the potential of delaying fruit softening by regulating cell wall-degrading enzymes, thus retain fruit quality.

Effects of trisodium phosphate treatment after harvest on storage quality and sucrose metabolism in jujube fruit.

BACKGROUND: Trisodium phosphate (TSP), generally recognized as safe (GRAS), could control postharvest diseases and maintain fruit quality. However, changes of fruit quality and sucrose metabolism in harvested jujube after TSP treatment remain largely unknown. In the current study, jujube fruit (cv. sanxing) was used to study the effects of TSP on storage quality and sucrose metabolism during storage at 20 ± 2 °C with 40-50% relative humidity (RH). RESULTS: The results showed that 0.5 g L-1 TSP treatment reduced weight loss and reduced sugar content, suppressed the reduction of fruit firmness, maintained ascorbic acid (AsA) content and inhibited respiratory rate of jujube fruit. In addition, TSP treatment also reduced acid invertase (AI) and neutral invertase (NI) activities in sucrose metabolism in jujube fruit. Sucrose synthase-cleavage (SS-c), sucrose synthase-synthesis (SS-s) and sucrose phosphate synthase (SPS) activities were also suppressed by TSP treatment. CONCLUSION: Treatment with TSP could effectively reduce enzymes activities in sucrose metabolism and maintain storage quality of jujube fruit during storage. © 2019 Society of Chemical Industry.