The feeding of heather (Calluna vulgaris) to Teladorsagia circumcincta infected lambs reduces parasitism but can detrimentally impact performance

Gastrointestinal nematode (GIN) infections impact small ruminant health, welfare, and production across farming systems. Rising anthelmintic resistance and regulation of synthetic drug use in organic farming is driving research and development of sustainable alternatives for GIN control. One alternative is the feeding of plants that contain secondary metabolites (PSMs) e.g., proanthocyanidins (PA, syn. condensed tannins) that have shown anthelmintic potential. However, PSMs can potentially impair performance, arising from reduced palatability and thus intake, digestibility or even toxicity effects. In this study, we tested the trade-off between the antiparasitic and anti-nutritional effects of heather consumption by lambs. The impact of additional feeding of a nematophagous fungus (Duddingtonia flagrans) on larval development was also explored. Lambs infected with Teladorsagia circumcincta or uninfected controls, were offered ad libitum heather, or a control chopped hay for 22 days during the infection patent period. Eight days into the patent period, parasitised lambs were supplemented (or remained unsupplemented) with D. flagrans for a 5-day period. Performance and infection metrics were recorded, and polyphenol levels in the heather and control hay were measured to investigate their association with activity. The lambs consumed heather at approximately 20% of their dry matter intake, which was sufficient to exhibit significant anthelmintic effects via a reduction in total egg output (P = 0.007), compared to hay-fed lambs; the magnitude of the reduction over time in heather fed lambs was almost 10-fold compared to control lambs. Negative effects on production were shown, as heather-fed lambs weighed 6% less than hay-fed lambs (P < 0.001), even though dry matter intake (DMI) of heather increased over time. D. flagrans supplementation lowered larval recovery in the faeces of infected lambs by 31.8% (P = 0.003), although no interactions between feeding heather and D. flagrans were observed (P = 0.337). There was no significant correlation between PA, or other polyphenol subgroups in the diet and egg output, which suggests that any association between heather feeding and anthelmintic effect is not simply and directly attributable to the measured polyphenols. The level of heather intake in this study showed no antagonistic effects on D. flagrans, demonstrating the methods can be used in combination, but provide no additive effect on overall anthelmintic efficacies. In conclusion, heather feeding can assist to reduce egg outputs in infected sheep, but at 20% of DMI negative effects on lamb performance can be expected which may outweigh any antiparasitic benefits.

Review of the beneficial and anti-nutritional qualities of phytic acid, and procedures for removing it from food products

Phytic acid (PA) is the primary phosphorus reserve in cereals and legumes which serves the biosynthesis needs of growing tissues during germination. It is generally considered to be an anti-nutritional factor found in grains because it can bind to minerals, proteins, and starch, limiting their bioavailability. However, this same mineral binding property can also confer a number of health benefits such as reducing the risk of certain cancers, supporting heart health, and managing renal stones. In addition, the ability of PA to bind minerals allows it to be used in certain food quality applications such as stabilizing the green color of vegetables, preventing lipid peroxidation, and reducing enzymatic browning in fruits/vegetables. These beneficial properties create a potential for added-value applications in the utilization of PA in many new areas. Many possible processing techniques for the preparation of raw materials in the food industry can be used to reduce the concentration of PA in foods to mitigate its anti-nutritional effects. In turn, the recovered PA by-products could be available for novel uses. In this review, a general overview of the beneficial and anti-nutritional effects of PA will be discussed and then dephytinization methods will be explained.

Optimization of the extrusion process through response surface methodology for improvement in functional and nutritional properties of soybean hull

Soybean hull as a rich and inexpensive source of dietary fiber and because of its health properties, is a good option for supplying dietary fiber to various food industries. Optimization of the extrusion process and the effects of its variables [Feed moisture (35-45%), screw speed (160-200 rpm), and temperature (75-95 °C)] were investigated on the structural, nutritional, and functional properties of soybean hull by response surface methodology. Based on response surface analysis, the maximum soluble dietary fiber content and water absorption index in addition to the minimum specific mechanical energy and anti-nutritional composition of tannin were obtained at a feed moisture content of 42.58%, screw speed of 182.46 rpm, and temperature of 87.43 °C. The extrusion process also increased the rate of swelling capacity, solubility index, yellowness, and redness of the samples. It also reduced the oil absorption index and lightness in comparison with the control. The FTIR spectroscopy did not show a new functional group and the urease test (trypsin inhibitor activity) was negative in the extruded samples.

Characterizing genotypic variation in biochemical composition, anti-nutritional and mineral bioavailability of some Nigerian yam (Dioscorea spp.) land races

The aim of this study was to characterize 43 genotypes from five yam species [Dioscorea rotundata (Poir), Dioscorea alata (Linn), Dioscorea bulbifera (Linn), Dioscorea cayenensis (Lam) and Dioscorea dumetorum (Kunith) Pax] which are major land races in Nigeria in terms of their chemical composition, nutritional, anti-nutritional and mineral bioavailability. Findings showed that there was genotypic variation in terms of chemical composition, mineral profile and bioavailability of the minerals among the germplasm. D. bulbifera had the highest cell wall carbohydrates, (cellulose: 3.2%, hemicelluloses, 2.1%, lignin, 1.1%, acid detergent fibre (ADF) 3.2%, neutral detergent fibre (NDF) 6.4%), D. rotundata had the highest oxalate (606 mg/kg). In conclusion, intra and inter-species variations exist among the yam germplasm in terms of their chemical composition, anti-nutritional and mineral bioavailability. Phytate content of the yam genotypes did not affect the bioavailability of Zn but Ca was affected significantly. The Ox:Ca ratio in most of the yam varieties were below one, thus bioavailability of Ca in yam by oxalate is variety dependent.

Studies on physico-chemical and cooking characteristics of rice bean varieties grown in NE region of India

Rice bean (Vigna umbellata) is grown in South and Southeast Asia, and the bean has gained importance due to its nutritional strength in terms of dietary fiber, quality protein and minerals. In current study, the nutritional and functional components, cooking and thermo-gravimetric properties of eleven rice bean varieties from NE India were investigated. Results revealed that the major nutrients among the varieties ranged as follows: 54.21-60.49% carbohydrates, 15.64-21.60% protein, 1.22-2.3% fat, 5.53-6.56% crude fibre, 3.34-3.8% ash; while the functional, anti-nutritional factors and mineral were present as 1189.32-1645.8 mg gallic acid equivalent (GAE)/100 g polyphenols, 205.38-432.14 mg/100 g phytic acid, 23.14-34.12 mg/100 g oxalate, 690.7-1589.5 mg/100 g saponins, 49.90-158.17 μg/100 g hydrocyanide, 111.51-168 calcium, 5.50-10.44 zinc, 3.72-8.37 iron. Principal component analysis revealed that varieties with higher calcium, iron and ash content had lower cooking time, swelling ratio, and cooked grain hardness. It is also revealed that varieties with higher weight loss at sixth stage in thermogravimetric graph had lower carbohydrate and higher protein content. Nagadal variety had higher fat, potassium, magnesium, calcium, sodium, iron, copper and chromium content and better cooking quality as compared to the other varieties. The study revealed that Nagadal variety was superior to other varieties with respect to mineral content, cooking and thermal properties and hence have better potential in the development of value added products.