Effects of fermented soybean meal on carbon and nitrogen metabolisms in large intestine of piglets.

Fermented soybean meal (FSM), which has lower anti-nutritional factors and higher active enzyme, probiotic and oligosaccharide contents than its unfermented form, has been reported to improve the feeding value of soybean meal, and hence, the growth performance of piglets. However, whether FSM can affect the bacterial and metabolites in the large intestine of piglets remains unknown. This study supplemented wet-FSM (WFSM) or dry-FSM (DFSM) (5% dry matter basis) in the diet of piglets and investigated its effects on carbon and nitrogen metabolism in the piglets' large intestines. A total of 75 41-day-old Duroc×Landrace×Yorkshire piglets with an initial BW of 13.14±0.22 kg were used in a 4-week feeding trial. Our results showed that the average daily gain of piglets in the WFSM and DFSM groups increased by 27.08% and 14.58% and that the feed conversion ratio improved by 18.18% and 7.27%, respectively, compared with the control group. Data from the prediction gene function of Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) based on 16S ribosomal RNA (rRNA) sequencing showed that carbohydrate metabolism function families in the WFSM and DFSM groups increased by 3.46% and 2.68% and that the amino acid metabolism function families decreased by 1.74% and 0.82%, respectively, compared with the control group. These results were consistent with those of other metabolism studies, which showed that dietary supplementation with WFSM and DFSM increased the level of carbohydrate-related metabolites (e.g. 4-aminobutanoate, 5-aminopentanoate, lactic acid, mannitol, threitol and ß-alanine) and decreased the levels of those related to protein catabolism (e.g. 1,3-diaminopropane, creatine, glycine and inosine). In conclusion, supplementation with the two forms of FSM improved growth performance, increased metabolites of carbohydrate and reduced metabolites of protein in the large intestine of piglets, and WFSM exhibited a stronger effect than DFSM.

Short communication: Changes in the composition of yak colostrum during the first week of lactation.

Although the great interest has been paid to colostrum utilization for calves, no systematic studies evaluating the compositional changes of yak colostrum during the first week after parturition have been reported. The aim of this study was to elucidate such postpartum nutritional changes. Colostrum samples from 12 multiparous (2-7 lactations) yaks, grazed on alpine pasture, were collected at exactly 1, 24, 48, 72, 96, 120, 144, and 168 h postpartum. Gross composition (fat, total solids, protein, and ash) were measured, as well as fat and water-soluble vitamins, fatty acid and mineral composition, and IgG. The colostrum, collected 1h postpartum, had the highest concentrations of crude protein, total solids, ash, vitamin A and E, ß-carotene, and most minerals (Na, Mg, Zn, Cu, and Fe). These components decreased rapidly within 24h. Similarly, at 24h postpartum, IgG content decreased to 7.5% of the value (87.78 mg/mL) at 1h postpartum. In contrast, the concentration of vitamin C increased from 1 to 24h and then decreased consistently thereafter to the lowest value at 168 h. Phosphorus and Ca contents showed an increasing trend from 24 to 168 h after calving. Lactose content increased from 2.88% at 1h to 4.96% at 48 h postpartum and was steady to 168 h. Total n-3 fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, and n-3-to-n-6 fatty acid ratio were proportionally similar as a percentage of total fatty acid methyl esters during the first 168 h of milk production. However, the proportion of total n-6 fatty acid content to total fatty acid methyl esters decreased from 3.07% at 1h to 2.60% at 24h. In summary, experimental results indicate colostrum should be provided to yak calves as soon as possible after birth to provide nutrients and enhance passive immunity.

A comparison of nitrogen utilization and urea metabolism between Tibetan and fine-wool sheep.

To study metabolic adaptation to harsh foraging conditions, an experiment was conducted to characterize and quantify N utilization efficiency and urea metabolism in Tibetan and fine-wool sheep fed 4 levels of dietary N (11.0, 16.7, 23.1, and 29.2 g N/kg DM) in 2 concurrent 4 × 4 Latin square designs. Urea kinetics were determined using continuous intrajugular infusions of 15N15N-urea. Urinary excretions of total N and urea N increased linearly (P < 0.001) with dietary N and were not different between breeds (P ≥ 0.37). Fecal N excretion increased with dietary N for Tibetan sheep but not for fine-wool sheep (linear dietary N × breed; P < 0.05). Nitrogen retention (both amount per day and percentage of N intake) increased with increasing dietary N concentration (P < 0.001), and the rates of increase were greater in fine-wool than in Tibetan sheep (linear dietary N × breed and cubic dietary N × breed; P < 0.05). In Tibetan sheep, N retention as a percentage of intake was greatest for diets containing 16.7 g N/kg DM, whereas it was maximal for fine-wool sheep when the diet contained 23.1 g N/kg DM. Urea N entry rate, urea N recycled to the gastrointestinal tract (GIT), and urea N returned to the ornithine cycle all increased with dietary N (P < 0.05), and all were greater in Tibetan than fine-wool sheep for the 11.0 g N/kg DM diet but were greater in fine-wool than Tibetan sheep for the diet with 29.2 g N/kg DM (linear dietary N × breed; P < 0.05). Urea N excreted in feces, both amount and fraction of GIT entry rate, was less in Tibetan than fine-wool sheep for the 11.0 and 16.7 g N/kg DM diets but similar for diets with 23.1 or 29.2 g N/kg DM (linear dietary N × breed; P < 0.01). For the lowest-protein diet, the fraction of urea N production recycled to the GIT was greater in the Tibetan than fine-wool sheep (88% vs. 82%), but for the diet with 29.2 g N/kg DM it was greater for fine-wool than Tibetan sheep (46% vs. 39%; linear dietary N × breed; P < 0.05). Plasma urea N increased more rapidly in response to increasing dietary N concentration for fine-wool sheep than for Tibetan sheep (linear dietary N × breed; P < 0.05). Urea tubular load and the amount and percentage of urea reabsorbed by the kidney were greater in Tibetan than fine-wool sheep (P < 0.05). These results suggest that Tibetan sheep have mechanisms that allow them to utilize N more efficiently than the fine-wool sheep when dietary N is inadequate.