Acceptability, Preferences, and Palatability of Diets Containing Summer and Winter Brassica Forage in Growing Pigs: A Pilot Study

Abstract

Brassica forage may be included in pigs’ diet as a dietary fiber ingredient to reduce feeding costs, benefit gut health, immune system, reproductive traits, and welfare. However, they contain antinutritional factors which may affect feeding behavior. This study evaluated feeding behavior of growing pigs offered winter (kale and swede) and summer (turnip and forage rape) brassicas incorporated on their diets as dried ground meal. Two consecutive experiments with six growing castrated male pigs were conducted. Experiment 1 evaluated the inclusion of turnip bulbs and forage rape, while experiment 2 studied inclusion of kale and swede bulbs. Brassica meal was included at 15% of the diet by replacing wheat middlings (control diet). In each experiment, pigs were offered experimental diets over six consecutive days for 10 min to test their acceptability (day 1–3) and preferences (day 4–6). No differences were found between diets that included brassicas and control diet in pigs’ acceptability or palatability (p > 0.05). However, during preference tests of winter brassicas, swede presented a higher consumption than control and kale (p < 0.05). This suggest that brassicas may be incorporated in growing pigs’ diets without negative effects in animals’ oral perception during short term feeding tests. Nevertheless, the long-term effects need to be explored.

In Vivo Digestibility and In Vitro Fermentation of High Dietary Fiber Forages in Growing Pigs’ Diets

“…Based on our results, where no differences in terms of digestibility were found, and those by Figueroa et al [12], who found that forage brassica meals did not negatively affect the preference or acceptability of the diet when incorporated at 15% in growing pig diets, we expect no differences in terms of growth performance. However, this needs to be evaluated in further research.…”

“…Digestion in the large intestine takes the longest amount of time (20-38 h) [48], which is why the bacteria would digest and ferment carbohydrates and proteins in greater quantities, obtaining more fatty acids in both short-and mid-chain VFAs. Additionally, turnip contains a greater amount of sugar than wheat middlings and rape, potentially changing the fermentation patterns [12,39]. Previous in vitro studies carried out with human fecal bacteria have shown that the fermentation of starch produces a higher proportion of butyric acid as a product of short-chain VFAs when compared to the fermentation of foods rich in pectin, such as brassicas that contain more than 300 g/kg DM of SF [40].…”

“…Although brassica forages have been extensively studied in ruminants, their use as a DF ingredient in pig diets lacks information. Recently, a pilot study showed that forage brassicas can replace wheat middlings in the diet without affecting the pigs' acceptability or palatability [12]; however, to the best of our knowledge, no information regarding its digestibility and in vitro post-gastric fermentation has been reported. This information would help in increasing the gap of knowledge about the inclusion of new highfiber ingredients in pigs' diets.…”

“…The SF is mainly composed of pectins (7-9%), galactans, and β-glucans, among others [7,8,10,11]. Although research focused on summer brassica inclusion in pig diets is limited, it has been shown that forage rape and turnips can be included in the diet without negative repercussions in terms of animals' oral perception [12].…”

The Effects of Turnip (Brassica rapa) Extract on the Growth Performance and Health of Broilers

“…In the 450 ppm treatment, the negative effect on weight gain in the first week, followed by reduced intake, suggests an antinutritional impact in the early stages of feeding the turnip extract that was unrelated to palatability. No adverse effects on intake of feeding turnips to pigs been recorded [ 20 ]; however, reduced intakes have been noted in sheep [ 21 ]. There are potentially negative effects of glucosinolates from turnips on performance; in particular their post-ingestional derivatives may interfere with iodine uptake and the production of triiodothyronine (T3) and thyroxine (T4) [ 22 ].…”