The Freedoms and Capabilities of Farm Animals: How Can Organic Husbandry Fulfill Them?

Organic farming promotes animal husbandry practices that consider the welfare of the animals on the farm. The concept of animal welfare and the standards that should encompass this concept have in many cases been largely generalised in practice, which leaves relevant aspects of animal freedom or capabilities insufficiently addressed. This chapter puts forth the prospect that the capabilities approach offers an appropriate practical platform by which to improve welfare in farm animals by meeting a wider range of their natural needs and abilities. The capabilities approach coupled with effective health planning could foster organic husbandry towards a more acceptable production system for farmers and consumers alike

Feeding behaviour of sheep fed lucerne v. grass hays with controlled post-ingestive consequences

International audienceUnderstanding what determines feeding behaviour in herbivores is essential to optimise the use of forages in breeding systems. Herbivores can evaluate foods by associative learning of their pre-ingestive characteristics (taste, odour, etc.) and their post-ingestive consequences. Post-ingestive consequences are acknowledged as influencing intake and food choices, but the role of pre-ingestive characteristics is still being debated. Our experiment was designed to test their separate effects on daily dry matter intake (DMI), intake patterns and short-term choices in sheep by crossing the nature of the hay orally consumed (o) ad libitum, lucerne (L) or grass (G), with the nature of the hay introduced into the rumen (r), L or G, at a rate of half the total amount of hay received the day before. We applied four treatments, Go/Gr, Go/Lr, Lo/Gr and Lo/Lr, to test the effects of (i) post-ingestive consequences with similar pre-ingestive characteristics (Go/Gr v. Go/Lr; Lo/Gr v. Lo/Lr) and (ii) pre-ingestive characteristics with similar post-ingestive consequences at the end of the feeding period (Go/Lr v. Lo/Gr). Six rumen-fistulated sheep underwent all the treatments over 11-day periods in a latin square design. Eating time was restricted to 6 h/day, intraruminal introductions were performed just before food offer and choice tests were conducted after food removal. For similar pre-ingestive characteristics, DMI increased when L hay was introduced into the rumen rather than G (P 0.05). Pre-ingestive characteristics or palatability per se did not therefore influence daily intake, although they influenced eating patterns. Pre-ingestive characteristics also greatly influenced short-term choices in favour of the hay that was not previously consumed, independently of any post-ingestive influence. This study confirms the effects of post-ingestive consequences on daily intake, but demonstrates that these variations are obtained by different behavioural adjustments under the influence of pre-ingestive characteristics. Preference for novelty, regardless of post-ingestive consequences, thus suggests that sheep may seek a diverse diet more for pleasure than for functional purposes, with implications for animal welfare

Diet learning through post-ingestive consequences in sheep: the case of starch and casein variously combined in the same foods

Ruminants generally succeed in selecting an appropriate diet relative to their nutrient requirements, and macronutrients such as energy and protein are considered as playing a primary role in their food preferences. Diet learning through post-ingestive consequences, evidenced by many studies that involved situations with simple discrimination tasks, may explain this ability to select a suitable diet. However, in more complex feeding environments where animals are faced with many plants varying both in their energy and protein contents, the extent to which such a mechanism operates is still uncertain. Our objective was to investigate a more complex feeding situation than previously tested and to determine whether lambs were able to associate three forages with both energy-based and protein-based post-ingestive consequences of various intensities. The doses of starch and casein used to elicit these post-ingestive consequences were chosen so that the apparent metabolisable energy and crude protein values of hays were within the range found in plants normally encountered under field conditions. We applied five treatments: EmPm, EhPm, EmPh, EhPh, where medium (m) or high (h) levels of nutrients (E5energy and P5protein) were associated with different hays, and E0N0 where no stimuli were associated. Each animal experienced only three treatments: E0N0–EmPm–EhPm or E0N0–EmPh–EhPh, each one being associated with one hay during conditioning, on the basis of one treatment per day over three consecutive days. Animals then had a choice between the hay associated with E0N0 and one of the two others, successively on the two following days. This procedure was repeated through five 1-week-long periods, and applied to two groups of lambs (n512) maintained at feeding levels sufficient for maintenance or for a 150 g/day growth rate. This experiment was complemented by a methodological trial that aimed to estimate the doses of starch and casein eliciting preferences and a post-trial that aimed to evaluate the effect of our treatments on sheep ruminal environment. The methodological trial showed that lambs perceived the stimuli and the doses, and the post-trial showed that treatments affected the ruminal environment. In the main experiment, the lambs preferred the rewarded hays but did not discriminate in their choices the variation of post-ingestive consequences due to energy and protein. This suggests that in situations closer to reality where animals experience many foods varying in nutrient contents, the learning process may be impaired. The lambs do not seem to have strictly relied on it for shaping their diet choices

Sheep use preingestive cues as indicators of postingestive consequences to improve food learning

International audiencePrevious work has shown that herbivores successfully learn to associate food sensory characteristics with postingestive consequences when the conditioning procedure is simple, whereas this ability breaks down when the learning task is made more complex. We hypothesized that sensory characteristics could act as indicators of postingestive consequences and that the presence of preingestive cues would improve the food learning of sheep in situations varying in complexity. Sixteen sheep were subjected to a first conditioning phase to associate 2 flavors added to alfalfa hay with either a positive or a negative consequence, induced by intraruminal administration of starch (330 mg/g of DMI) or LiCl (5 mg/g of DMI). Sheep progressively decreased their choice of the flavored hay associated with the negative consequence (P < 0.05). This procedure provided sheep with experience with postingestive consequences associated with the different flavors. In a second conditioning phase, the experienced sheep and 16 naïve sheep were divided into groups of 8 and subjected to either a simple or a complex conditioning procedure [i.e., the 2 flavors were offered on separate days (simple conditioning) or simultaneously within a day (complex conditioning)]. The 2 flavors applied to grass hay were associated with either positive (starch, 330 mg/g of DMI) or negative (LiCl, 10 mg/g of DMI) consequences. As hypothesized, sheep in the simple conditioning group expressed a greater aversion to the flavored hay associated with the negative consequence than did those in the complex conditioning group (0.303 +/- 0.035 vs. 0.474 +/- 0.035 respectively; P < 0.01). Experienced sheep rejected the flavor associated with the negative consequence more strongly than did naïve sheep, regardless of the conditioning procedure (0.304 +/- 0.029 vs. 0.470 +/- 0.041 respectively; P < 0.05). The initial increased preference for aniseed (0.80 +/- 0.04), however, greatly influenced food learning because sheep negatively conditioned on this flavor expressed less avoidance than those negatively conditioned on orange (0.53 +/- 0.04 vs. 0.25 +/- 0.03 respectively; P < 0.01). In conclusion, the simultaneous scenario was actually perceived as complex by all sheep, and experienced sheep were more efficient in food learning than naïve sheep in both the simple and complex learning contexts. The sheep were thus able to generalize the association between sensory cues and postingestive consequences, especially in a complex environment, and then to use these sensory cues as indicators of postingestive consequences

How do herbivores trade-off the positive and negative consequences of diet selection decisions?

Herbivory is central to ecosystem function, and herbivores, through diet selection, exert a major influence on vegetation composition with consequent effects for associated fauna and human livelihoods. Understanding diet selection behaviour is therefore important to allow effective prediction of herbivore impacts on vegetation under different scenarios. Herbivores learn about foods by associating them with the positive postingestive effects of nutrients and the negative postingestive effects of toxins. However, the extent to which trade-offs are made between positive and negative effects, occurring simultaneously, and how this trade-off might be altered by the underlying nutritional status of herbivores are unclear. We investigated these effects using 36 goats, Capra hircus, half of which were on a low nutritional regime and half were moderately well fed. We offered three conifer species to the goats, on 3 consecutive days per week for 3 weeks. While the goats were consuming the conifers, they received one of three levels of a positive nutritional stimulus, simulating nutritional rewards, and one of three levels of a negative stimulus, simulating the effects of plant secondary compounds. Goats preferred conifers paired with positive effects and avoided those paired with negative effects in a dose-dependent way. Underlying nutritional status did not influence the response to the positive and negative postingestive effects. We conclude that diet choice in response to learning about postingestive effects represents a simple integration of the positive and negative consequences of consuming particular plants and that this balance is not greatly influenced by minor differences in nutritional status