Plasma GLP-1 response to oral and intraduodenal nutrients in health and type 2 diabetes – impact on gastric emptying

Context Both gastric emptying and the secretion of glucagon-like peptide-1 (GLP-1) are major determinants of postprandial glycemia in health and type 2 diabetes (T2D). GLP-1 secretion after a meal is dependent on the entry of nutrients into the small intestine, which, in turn, slows gastric emptying. Objective To define the relationship between gastric emptying and the GLP-1 response to both oral and small intestinal nutrients in subjects with and without T2D. Design We evaluated: (i) the relationship between gastric emptying (breath test) and postprandial GLP-1 levels after a mashed potato meal in 73 T2D subjects; (ii) inter-individual variations in GLP-1 response to (a) intraduodenal glucose (4kcal/min) during euglycemia and hyperglycemia in 11 healthy, and 12 T2D, subjects, (b) intraduodenal fat (2kcal/min) in 15 T2D subjects, and (c) intraduodenal protein (3kcal/min) in 10 healthy subjects; and (iii) the relationship between gastric emptying (breath test) of 75g oral glucose and the GLP-1 response to intraduodenal glucose (4kcal/min) in 21 subjects (9 healthy, 12 T2D). Results The GLP-1 response to the mashed potato meal was unrelated to the gastric half-emptying time (T50). The GLP-1 responses to intraduodenal glucose, fat and protein varied substantially between individuals, but intra-individual variation to glucose was modest. The T50 of oral glucose was related directly to the GLP-1 response to intraduodenal glucose (r=0.65, P=0.002). Conclusions In a given individual, gastric emptying is not a determinant of the postprandial GLP-1 response. However, the intrinsic gastric emptying rate is determined in part by the responsiveness of GLP-1 to intestinal nutrients.

Performance of broiler chickens fed maize-based diets substituted with graded levels of sweet potato meal

The performance of Ross broiler chickens fed on Sweet Potato Meal (SPM) as a dietary source of energy was studied. The study was carried out at both starter (0-4 wks) and finisher (5- 9 wks) phases. In both phases, SPM was incorporated at graded levels of 0. 10, 20, 30, 40 and 50 percent and dietary proteins were adjusted to make the diets iso-nitrogenous. In the starter phase, three replicates of I5 birds each were randomly allocated to each of the 6 treatments in a completely randomized design (CRD) experiment while the number of birds per replicate was reduced to 14 for the finisher phase using the same experimental design. Parameters measured or calculated include feed intake, body weight gain, feed efficiency, feed costs, feed cost/kg weight gain, mortality and carcass characteristics. The results showed similar trends in both phases. Differences in the feed intake were not significant (P>0.05) while weight gain, feed cost/kg weight gain and total cost of rearing the birds decreased significantly (P<0.05). The Control, 10% 20% and 30% SPM diets gave similar weight gain and feed gain ratio. The Control gave the best performance in both starter and finisher phases, although its performance was not significantly different (P>0.05) from that of the 30%SPM diet Sweet Potato Meal level had no adverse effects on mortality and carcass characteristics. It is therefore concluded from this study that SPM should not be included beyond 30% level in a maize-based diet when protein requirement of birds is satisfied.

Performance of weaner rabbits fed graded levels of sun-dried sweet potato tuber meal (Ipomea batatas) diets

Forty weaned rabbits (8 weeks old) of mixed sexes and breed, with an average initial live-weight of 680g, were used in a nine-week feeding trial to evaluate their performance on diets in which sun-dried sweet potatoe tuber meal (Ipomoea batatas) was included at the rate of 0, 10, 20, 30 and 40% levels in a CP Isonitrogenous diets. Performance parameters showed that feed intake, weight gain and feed to gain ratio were not significantly different between treatments. Values obtained were poorer for the sweet potato based diets compared to the control. No mortality was recorded during the experiment. Carcass and oragn weights expressed as percentage of live-weight showed no significant differences (P>0.05) across the treatments. It was concluded that sweet potato meal can be included up to 40% level in diets of young rabbits.

Replacement of Value of Sweet Potato(Ipomea Batatas) Meal For Maize in Practical Diets Fed to Quail (COnturnix cotu-rnix japomica) Chicks

A six- week feeding trial was conducted to determine the value of sweer potato in diets fed to216 Japanese quail chicks in a brooding house. Four isonitrogenous (22%CP) diets tagged A, B<C and D incorporating graded levels (0. 13.73, 23,73 and 38.73%) of sweet potato meal respectively as replacement for maize were used in the trial. The M.E levels of the diets flunctuated between 2692; diets D and 2708kcal/kg M.E; diets B. Each treatment was replicated thrice. Food intake was higher (p<0.05) on diet B (818.62) than the rest of the diets (A:702.10g, C: 688.51 and D: 689.96g). Difference in weight gain (A:122g, B:130.50g. C:121.37g, D:122.15g) were not significant( p>0.05) among the treatments. Feed cost/kg gain was higher(p<0.05) for diet D(134.81) than other diets (A:97.87, B:94.23, C:104.94). Results of this study showed that dietry level of 38.73% sweet potato meal was suitable for growth of Japanese quail chicks provided the diets are isonitrogenous and contained metabolizable energy of between 2692 and 2798kcal/kg

Comparative effect of feeding sundried sweet potato (Ipomoea batatas (L) Lam) meal and its whole meal to weaner rabbits

An experiment was conducted to evaluate the comparative effect of feeding sundried sweet potato and its whole meal to weaner rabbits. The proximate analysis conducted revealed that sundried sweet potato meal and whole sundried sweet potato meal samples were rather low in protein contents as compared to maize. Twenty seven Weaner rabbits averaging 0.35kg were randomly allotted to 3 treatment groups in a completely randomized design. Each treatment group was replicated 3 times. Sundried Sweet potato meal and its whole meal replaced maize at 20% inclusion level. Treatments 1, 2, and 3 contained the control, sundried sweet potato meal (SSPM) and whole sundried sweet potato meal (WSSPM) respectively at 20% levels of inclusion. The weaner rabbits were fed ad-libitum throughout the experimental period. Significant differences (p<0.05) were observed for growth performance of the rabbits in average daily weight gain, average daily feed intake and feed conversion ratio in the weaner rabbits using sundried sweet potato and its whole meal. The values of mean daily weight gain ranged from 16.33g in treatment 2 (SSPM) to 18.47g in treatment 1 (control). Treatment 3 (WSSPM) gave a higher value that is comparable (p>0.05) to that of the control diet but better (p<0.05) than that of treatment 3 (SSPM). The values of average daily feed intake also ranged from 43g in treatment 2 (SSPM) to 50g in treatment 1 (control). WSSPM was consumed more than (p<0.05) than the SSPM which however influenced the cost of total feed consumed. Moreover, the values of feed conversion ratio (FCR) ranged from 2.54 in treatment 3 (WSSPM) to 2.70 in treatment 1 (control). Significant differences (p<0.05) were also observed in bio-economics of production of weaner rabbits using the test diets. The cost per kg feed, cost of total feed consumed per rabbit, cost per kg weight gain and revenue of the rabbits fed the test diets were significantly lower than the control diet however, the cost per kg weight gain was lower (p<0.05) for treatment 3 (WSSPM). For gross margin, WSSPM value was significantly higher (p<0.05) than SSPM value and the control diet. It was concluded that whole sundried sweet potato meal can be a good feed ingredient in rabbit diet.

Performance of finisher broiler chickens fed diets containing unpeeled sweet potato meal as partial substitute for maize

This study evaluated effects of unpeeled sweet potato meal (USPM) on performance of finisher broiler chickens. A total of 180 one day-old broiler chicks were used for the experiment. Brooding operation was carried out for 2 weeks. Thereafter, the broiler chickens were managed for additional 2 weeks with provision of starter diet and water ad-libitum. At four weeks old, they were equalized for weight and distributed into three dietary treatments (control, 10% and 15% unpeeled sweet potato meal as partial replacement for maize) each replicated four times with 15 birds per replicate; laid out in a completely randomized design. The birds were managed intensively throughout the experimental period until they attained 7 weeks of age. Data collected were subjected to one-way analysis of variance. Results revealed that the inclusion of unpeeled sweet potato meal up to 15% in diets of finisher broiler chickens did not significantly affect the growth performance indices, haematological parameters, carcass traits and most of the serum metabolites except albumin which showed significant variation and ranged from 1.35 g/dl (15% USPM) to 1.90 g/dl (control). Least significant cost (N129.73) per kg feed was recorded in birds fed diet containing 15% USPM relative to highest cost (N136. 63) per kg feed observed in birds fed control diet. Conclusively, incorporation of unpeeled sweet potato meal up to 15% in diet of finisher broiler chickens reduced cost per kg of broiler finisher diet and had no detrimental implications on growth performance, haematological parameters, serum metabolites and carcass traits in chickens.

Carbohydrate Sources, Within a Higher Protein Breakfast, Differentially Effect Postprandial Appetite Response in Adults with Metabolic Syndrome: A Pilot Study

Objectives The objective of this study was to determine the effect of carbohydrate source within a higher protein breakfast on postprandial appetite response in adults with metabolic syndrome. Methods Fourteen adults with metabolic syndrome were randomly assigned to consume one of three iso-caloric, higher protein breakfasts (352 kcal; 26.5 ± 0.3 g Pro; 20.0 ± 0.5 g CHO; 19.8 ± 0.3 g 18.0 ± 0.1 g Fat) containing servings of different carbohydrate sources: white potatoes (n = 5; 5 female; 37.6 ± 8.5 y; 98.0 ± 14.1 kg; 39.5 ± 7.3 BMI); 2) processed potatoes (hash browns) (n = 2; 1 female,1 male; 53.0 ± 15.0 y; 81.4 ± 17.0 kg; 29.6 ± 3.0 BMI); or 3) starchy carbohydrate (white rice; n = 5; 4 female,1 male; 33.6 ± 5.0 y; 95.1 ± 18.2 kg; 35.3 ± 4.7 BMI). All participants reported to the lab following an overnight fast. Participants were served their assigned meal (quiche) and were given 15 minutes to fully consume the entire portion. Appetite was assessed via visual analogue scale (VAS) with opposing anchors (e.g., “extremely hungry” or “not hungry at all”) at time points 0, 15, 30, 60, 90, 120, 180 and 240 min. Data were analyzed using Prism GraphPad version 8.0. Significance was set at P &lt; 0.05. Results Although not significant, participants who consumed the starchy carbohydrate meal reported increased hunger (182%), desire to eat (64%), and decreased fullness (8%) when compared to participants consuming the potato meal. In addition, the starchy carbohydrate meal consumption was a significantly associated with a desire for sweetness (P &lt; 0.05). No significant differences in appetite were observed between participants consuming the potato meal and the processed potato meal. Conclusions Preliminary results indicate the source of carbohydrate as part of a higher protein breakfast influences postprandial appetite response in adults with metabolic syndrome, however further research is needed. Funding Sources Alliance for Potato Research and Education.

Strategies to include sweet potato meal associated with the use of exogenous enzymes, in broiler chicken feed

SUMMARY This work evaluated the effect of including sweet potato meal (SPM), as an alternative to corn in broiler chicken diets, on performance, carcass yield, intestinal morphometry, organ biometry, meat quality and drumstick pigmentation. The study used 936 male Cobb-500 chicks. The experiment had a completely randomized, 3x2 factorial design, with three diet types. These included corn as the energetic ingredient in the standard diet (corn-soybean meal, CSM), and an increasing (ISP) and decreasing (DSP) inclusion of sweet potato meal as a corn substitute, in association with exogenous enzymes, for a total of six treatments with six repetitions and 26 birds per plot. During the period of 1 to 21 days, there was an interaction (P<0.05) for the weight gain (WG) variable; the CSM diets promoted greater WG in relation to the ISP and DSP groups, when supplemented with exogenous enzymes. There was an increase (P<0.05) in surface absorption of the jejunum villi and relative weight of the pancreas, and worse feed conversion (FC), for the ISP and DSP diets. With exception of the pancreas, for the entire period of 1 to 39 days the performance, yield of the carcass and cuts, meat quality, relative weight of the liver, and feet pigmentation variables were not affected (P>0.05) by the factors evaluated. Sweet potato meal, independent of the inclusion program (ISP/DSP) and enzyme supplementation, could partially substitute corn in broiler chicken feed, guaranteeing good performance, carcass yield and meat quality.