Limited access to high-quality feed protein for pigs has made it necessary to evaluate new protein sources that both promote sustainable pig production and meet the nutritional requirements of pigs. Providing pigs with roughage has positive effects on their behaviour and gut health. However, roughage is seldom given as a part of the pigs' diet and often has a long straw length. Knowledge is lacking on the effect of feeding silage with smaller particle size and as a part of the pigs' diet on pig behaviour and welfare. This study evaluated the influence of feeding fattening pigs silage with different particle sizes on aggressive encounters, measured as the number of skin lesions, and on the occurrence of gastric lesions and ulcers. In total, 128 Swedish Yorkshire x Hampshire pigs were fed either a commercial control feed without silage (Pellet-C), or silage mixed with commercial feed, either in a pellet (Pellet-S) or in a total mixed ration (TMR) with chopped (TMR-Ch) or intensively treated silage (TMR-Ex). Skin lesions were assessed twice in the study according to the Welfare Quality (R) protocol. The first assessment was performed when the pigs were 105 days old and the second assessment at 132 days of age. Gastric lesions were examined in both the pars oesophagea and the pars glandularis region of the stomach. Stomachs were collected after slaughter, and gastric lesions were scored based on established scoring criteria. There was a treatment x assessment interaction on the number of skin lesions on the ear (P = 0.049). Apart from this interaction, no other effect of treatment on the number of skin lesions could be observed between the treatments or the assessment occasions. Treatment had a clear effect on the occurrence of gastric lesions and pigs fed the fresh silage (TMR-Ch and TMR-Ex) had a lower occurrence of gastric lesions and ulcers compared to the pelleted treatments (Pellet-C and Pellet-S) (P = 0.001). This study could not show any clear reduction effect of dietary silage inclusion on skin lesions. However, feeding silage in TMR significantly reduced the occurrence of stomach ulcers. (c) 2023 The Author(s). Published by Elsevier B.V. on behalf of The Animal Consortium. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

This study investigated activity, preferred pen location and social interactions in female piglets (0-10 weeks of age, N = 98) intended for breeding. Piglets were housed in pens where the sow and the piglets were loose-housed without (CP) or with access to the neighbouring pen week 2-5 (AP). Female piglets of two genetic lines (Dutch and Swedish Yorkshire (DY, SY)) from 26 litters were selected within 24 h after birth. DY piglets in the AP treatment spent more time in the neighbouring pen than SY (24.0% vs 19.0%), while AP piglets of both genetic lines spent less time lying down before weaning than CP. At weaning, CP piglets increased their time in the piglet corner and spent less time lying. SY piglets were less responsive to social interactions. The results confirm previous findings on favourable effects of early social mixing on piglets' behavioural responses to weaning also when sows are individually loose-housed.

The effects of early supplementation with oat β-glucan during the suckling period on piglet gut microbiota composition, concentrations of short-chain fatty acids, and gut physiological markers were assessed. Fifty piglets from five litters, balanced for sex and birth weight, were divided within litters into two treatment groups: β-glucan and control. Piglets in the β-glucan group received the supplement three times/week from day 7 of age until weaning. Rectal swab samples were collected from 10 piglets per treatment group (balanced across litters) from week 1 to week 4, and plasma samples were collected at 1, 3, and 4 weeks of age. Additional samples of intestinal tissues and jugular and portal vein plasma were collected from 10 animals at weaning (one per treatment group and litter). The concentrations of short-chain fatty acids in plasma and the microbiota composition in rectal swabs were mainly influenced by piglet age, rather than the supplement. There were significant differences in microbiota composition between litters and several correlations between concentrations of short-chain fatty acids in plasma and specific microbial taxa in rectal swabs. Overall, β-glucan supplementation did not have any clear impact on the gut environment in suckling piglets, whereas a clear age-related pattern emerged.

In humans, contrasting emotional states can lead to a broadening or narrowing of attentional scope. Whether this is also the case in animals has yet to be investigated. If confirmed, measurement of attentional scope has potential as a novel cognitive method of welfare assessment. In this study, we therefore aimed to investigate a test of attentional scope as a measure of emotional state in animals. We did this by inducing four putatively different emotional states in dogs (N = 10), varying in valence (positive, negative) and arousal (high, low), in two different reward contexts (food rewards in Experiment 1, social rewards in Experiment 2) and then assessing dogs’ behavioural responses in a test of attentional scope. We also recorded heart rate variability (HRV) parameters as additional confirmatory affective indicators. In Experiment 1, the dogs showed a narrowing of attentional scope after the induction of both positively valenced emotional states. That dogs were in a positive state was supported by the reduced Standard Deviation of normal-to-normal R-R intervals (SDNN) and the reduced Low Frequency (LF) and Very Low Frequency (VLF) HRV. In Experiment 2, when responses to social rewards were examined, we did not detect any statistically significant differences in attentional scope between the emotional states, but dogs had a slightly narrow attentional scope in the negatively valenced emotional states. The LF tended to be reduced in the high arousal positive treatment. In conclusion, our study provides the first indication that emotional states can also alter attentional scope in animals. The results justify further investigation of this approach for use in animal welfare assessment, although additional studies are needed to refine predictions.

Gut microbes play an important role in regulating brain processes and influence behaviour, cognition and emotional states in humans and rodents. Nevertheless, it is not known how ingestion of beneficial microbes modulates emotional states in piglets and whether it can improve welfare. Here we use an attention bias task to assess the effects of Lactobacillus reuteri ATCC-PTA-6475 and Lactobacillus plantarum L1-6 supplementation early in life on emotional states in 33 piglets compared to 31 placebo supplemented piglets. We hypothesized that Lactobacillus supplementation would reduce vigilance behaviour (head at shoulder height or higher) and attention (head oriented towards the threat) in response to an auditory threat. The results showed that the control group increased vigilance behaviour in response to the threat, but there was no increase in the probiotics group. Despite the increased vigilance, the control group paid less attention to the threat. One explanation may be that control piglets avoided looking in the direction of the threat just because they perceived it as more threatening, but further research is necessary to confirm this. In conclusion, Lactobacillus supplementation may be a suitable tool to reduce anxiety, promote a more appropriate response to a challenge and so improve welfare.

Tail biting is an abnormal behaviour that causes stress, injury and pain. Given the critical role of the gut-microbiota in the development of behavioural problems in humans and animals, the aim of this study was to determine whether pigs that are biters, victims of tail biting or controls (nine matched sets of pigs) have a different microbiota composition, diversity and microbial metabolite profile. We collected faecal and blood samples from each individual for analysis. The gut microbiota composition was most different between the biter and the control pigs, with a higher relative abundance of Firmicutes in tail biter pigs than the controls. Furthermore, we detected differences in faecal and plasma short chain fatty acids (SCFA) profiles between the biter and victim pigs, suggesting physiological differences even though they are kept in the same pen. Thus, in addition to supporting an association between the gut microbiota and tail biting in pigs, this study also provides the first evidence of an association between tail biting and SCFA. Therefore, further research is needed to confirm these associations, to determine causality and to study how the SCFA profiles of an individual play a role in the development of tail biting behaviour.

Introduction Environmental challenges are part of everyday life for most domestic animals. However, very little is known about how animals cope emotionally and physiologically with cumulative challenges. This experiment aimed to determine the impact of long-term exposure to environmental challenges on the affective state and hypothalamic-pituitary-adrenal (HPA) axis responses to a subsequent additional acute shearing challenge. Methods Sheep were exposed to either a long-term environmental challenge (rest disruption and individual housing) in order to induce chronic stress (chronic stress group) or control conditions (group housing in a field with low stress handling and daily feed rewards, control group). Judgement and attention bias were assessed as measures of the emotional state following several days of the challenge or control treatment (pre-shearing tests). In addition, the responsiveness of the HPA-axis was evaluated using a combined Corticotropin Releasing Hormone and Arginine Vasopressin (CRH/AVP) challenge. Finally, all animals were exposed to an acute shearing challenge, then judgement bias (post-shearing test), HPA-axis and internal body temperature responses were determined. Results In the pre-shearing judgement bias test, the chronic stress group slightly increased optimism compared to the control treatment. In the attention bias test, the chronic stress group showed reduced vigilance behaviour towards a predator threat and a quicker approach to the food compared to the control treatment. The chronic stress group also had lower plasma ACTH concentrations in response to the CRH/AVP challenge compared to the control group, no differences in cortisol concentrations were found. In the post-shearing judgement bias test, differences in optimism were no longer evident between the chronic stress and control groups. Plasma ACTH concentrations and body temperatures showed a greater increase in response to shearing in the chronic stress group compared to the control group. Conclusion Our results suggest that long-term exposure to challenges biased cognitive measures of the affective state towards an increased expectation of a reward and reduced attention towards a threat. The exaggerated ACTH responses in the chronic stress group may be indicative of HPA-axis dysregulation. Despite a period of challenge exposure in the chronic stress group, judgement bias responses to the shearing challenge were similar in the chronic stress and control groups; the reasons for this need further investigation. The altered affective state together with signs of HPA-axis dysregulation may indicate an increased risk of compromised welfare in animals exposed to long-term environmental challenges.

The objective of this study was to evaluate the effect of morphine on social and non-socialplay behaviour in calves. Twelve calves experienced four treatments in a cross over 2 × 2 factorialdesign: Calves received an intravenous injection of morphine or saline 10 min prior to being testedindividually or in pairs in an arena for 20 min. Play behaviour was continuously recorded in thearena test. Lying times were recorded in the home pen. Cortisol concentrations were measuredbefore and after testing. In the arena test, calves given morphine tended to perform more social playevents than calves given saline, however, morphine administration had no effect on locomotor play.Calves given morphine spent less time lying than calves given saline during the first 4 h afterreturning to the home pen. Cortisol concentrations were suppressed in calves given morphine.Administration of morphine appeared to increase social play but had no effect on locomotor playin calves. This study highlights the importance of investigating different aspects of play behaviourin animals as some may be more indicative of a positive affective state than others. More studiesinvestigating the effects of morphine on play are needed to confirm the results found in this study.

Humans and animals show increased attention towards threatening stimuli when they are in increased states of anxiety. The few animal studies that have examined this phenomenon, known as attention bias, have applied environmental manipulations to induce anxiety but the effects of drug-induced anxiety levels on attention bias have not been demonstrated. Here, we present an attention bias test to identify high and low anxiety states in sheep using pharmacological manipulation. Increased anxiety was induced using 1-methyl-chlorophenylpiperazine (m-CPP) and decreased anxiety with diazepam, and then we examined the behaviour of sheep in response to the presence of a dog as a threat. Increased attention towards the threat and increased vigilance were shown in sheep that received the m-CPP and reduced in sheep receiving the diazepam. The modulated attention towards a threat displayed by the m-CPP and diazepam animals suggests that attention bias can assess different levels of anxiety in sheep. Measuring attention bias has the potential to improve animal welfare assessment protocols.

Qualitative behavioural assessment (QBA) is based on observers' ability to capture the dynamic complexity of an animal's demeanour as it interacts with the environment, in terms such as tense, anxious or relaxed. Sensitivity to context is part of QBA's integrative capacity and discriminatory power; however, when not properly managed it can also be a source of undesirable variability and bias. This study investigated the sensitivity of QBA to variations in the visual or verbal information provided to observers, using free-choice profiling (FCP) methodology. FCP allows observers to generate their own descriptive terms for animal demeanour, against which each animal's expressions are quantified on a visual analogue scale. The resulting scores were analysed with Generalised Procrustes Analysis (GPA), generating two or more multi-variate dimensions of animal expression. Study 1 examined how 63 observers rated the same video clips of individual sheep during land transport, when these clips were interspersed with two different sets of video footage. Scores attributed to the sheep in the two viewing sessions correlated significantly (GPA dimension 1: rs=0.95, P<0.001, GPA dimension 2: rs=0.66, P=0.037) indicating that comparative rankings of animals on expressive dimensions were highly similar, however, their mean numerical scores on these dimensions had shifted (RM-ANOVA: Dim1: P<0.001, Dim2: P<0.001). Study 2 investigated the effect of being given different amounts of background information on two separate groups of observers assessing footage of 22 individual sheep in a behavioural demand facility. One group was given no contextual information regarding this facility, whereas the second group was told that animals were moving towards and away from a feeder (in view) to access feed. Scores attributed to individual sheep by the two observer groups correlated significantly (Dim1: rs=0.92, P<0.001, Dim2: rs=0.52, P=0.013). A number of descriptive terms were generated by both observer groups and used in similar ways, other terms were unique to each group. The group given additional information about the experimental facility scored the sheep's behaviour as more 'directed' and 'focused' than observers who had not been told. Thus, in neither of the two studies did experimentally imposed variations in context alter the characterisations of animals relative to each other, but in Study 1 this did affect the mean numerical values underlying these characterisations, indicating a need for careful attention to the use of visual analogue scales.

Qualitative behavioural assessment (QBA) has been used to quantify the expressive behaviour of animals, and operant tests have been used to quantify measures of behavioural need. In this study we compared measures of behavioural expression and behaviour in operant tests. We examined the behavioural expression of pregnant ewes of body condition score (BCS) 2 and 3. The ewes were exposed to a feed motivation test in which they received a food reward. Pregnant ewes (48–70 days gestation) were assessed during a food motivation test after they had been maintained at BCS 3 (n = 7) or given a decreasing plane of nutrition that resulted in slow loss of 1 BCS unit (over 10–12 weeks; n = 7) or a fast loss of 1 BCS unit (over 4–6 weeks; n = 7). The feed motivation test involved ewes having the opportunity to approach a food reward and then being moved a given distance away from the reward by an automatic gate; they could then subsequently return to the feeder. Continuous video footage of each ewe during one cycle of the gate (approaching and returning from the food reward) was shown in random order to 11 observers who used their own descriptive terms (free-choice profiling methodology; FCP) to score the animals using QBA. Data of the assessment were analysed with generalised Procrustes analysis (GPA), a multivariate statistical technique associated with FCP. The research group also quantified the feeding behaviour of sheep in the same clips. These behaviours included how sheep approached the feeder, behaviours exhibited at the feeder, and how sheep returned from the feeder. There was consensus amongst observers in terms of their assessment of behavioural expression of the sheep (P < 0.001). The GPA found three main dimensions of assessed behavioural expression in the sheep, which together explained 44% of the variation observed. GPA dimension 1 differed between the three treatment groups (P < 0.05): ewes maintained at BCS 3 scored low on GPA dimension 1 (i.e. were described as more calm/bored/comfortable) compared with ewes that had a slow declining BCS (described as more interested/anxious/excited). GPA dimension 2 scores were not significantly different between treatment groups. However, quantitative behaviours exhibited by sheep during the clips were correlated with qualitative behavioural assessments made by the observers. Animals that spent more time ‘sniffing and looking for more feed’ were attributed lower GPA 2 scores (described as more hungry/searching/excited) (P < 0.05), and animals that ‘did not walk directly to the food reward (but stopped along the way)’ were attributed significantly higher GPA 2 scores (more curious/intimidated/uneasy) (P < 0.01). GPA dimension 3 scores also did not differ between the treatment groups; however, sheep that had a higher number of feeding events during the entire 23-h feed motivation test were attributed lower GPA dimension 3 scores (they were described as more hungry/bold/interested) (P < 0.05), and sheep that consumed a larger amount of the feed reward were attributed higher GPA dimension 3 scores (more curious/concerned/reserved) (P < 0.05). We conclude that QBA is a valuable method of assessing sheep behavioural expression under the conditions tested, in that it provided an integrative characterisation of sheep behavioural expression that was in agreement with quantitative behavioural measures of feeding.

Food restriction is considered to be a welfare issue in extensively reared animals. However, the effects of food restriction on the affective state, and its physiological regulation, are unknown. In Experiment 1, we aimed to assess the effects of increased plasma concentrations of acyl-ghrelin on judgement bias (an indicator of affective states) by fasting sheep for 24h or by ghrelin administration. In Experiment 2, we aimed to assess the effects of chronic food restriction on judgement bias and attention bias towards a food-related cue. For the judgement bias test, sheep were trained in an arena to approach a positive location cue associated with conspecifics and not approach a negative location cue associated with a dog. Three non-trained, non-reinforced ambiguous location cues were situated between the positive and negative locations. Attention bias towards a food-related cue was assessed by placing an empty food bucket against the wall of the arena halfway between the entry point and the positive location. In Experiment 1, sheep were divided into three treatments; 24h fast, ghrelin administration or control. Judgement bias, locomotor activity and plasma cortisol concentrations were assessed. The ghrelin treated group tended to express a more pessimistic bias compared to the control group (P<0.1), and plasma cortisol concentrations tended to be increased (P<0.1). In Experiment 2, sheep were subjected to a high feeding level (HF) or low feeding level (LF) for 7days. The LF group tended to show a more optimistic judgement bias (P<0.1). When the food-related cue was presented, LF ewes took longer to reach the positive location (P<0.001), spent longer with their head inside the bucket (P<0.001) and more time interacting with the bucket (P<0.01). This study provides preliminary evidence that food restriction alters judgement bias and attention bias towards a food-related cue which may indicate altered affective states of sheep.

This study investigated the involvement of the opioid system in modulating the affective state after the consumption of palatable and unpalatable rewards, using judgement bias as an indicator of the affective state. We hypothesised that consuming a palatable food reward would generate a more optimistic bias compared to receiving unpalatable wood chips. We hypothesised that morphine administration would further enhance the optimistic judgement bias after consumption of a food reward while reducing a pessimistic bias after receiving wood chips. Naloxone administration was expected to prevent the formation of an optimistic bias after consumption of a food reward, and was expected to have little effect after receiving the wood chips. The judgement bias arena consisted of a positive and a negative location cue, associated with conspecifics and a dog, respectively, as well as three non-reinforced ambiguous location cues between the positive and negative locations. Thirty sheep were successfully trained to approach the conspecifics and avoid the dog. Following training, sheep were randomly assigned to one of three treatments; morphine (1 mg/kg), naloxone (2 mg/kg) and control. Within each treatment, half the ewes received a small food reward and the other half wood chips before exposure to each of the five locations. Judgement bias was assessed by recording the latency to approach the five locations. Animals receiving the food reward approached the locations faster than animals receiving the wood chips (0.83 ± 0.04 and 1.00 ± 0.04 log-transformed latencies (s), respectively, P < 0.01). The latency was also near-significantly affected by a treatment × reward type interaction (P = 0.05), mostly due to the morphine treated ewes approaching the locations faster after receiving the food reward (log-transformed latencies (s): 0.82 ± 0.07 for control sheep after consuming food, 0.71 ± 0.07 for morphine treated sheep after food, 0.96 ± 0.07 for naloxone treated sheep after food, 0.94 ± 0.07 for control sheep after wood chips, 1.07 ± 0.07 for morphine sheep after wood chips and 1.00 ± 0.07 for naloxone sheep after wood chips). These results show that consumption of a food reward induced an optimistic judgement bias and suggest that morphine administration further enhanced this optimistic judgement bias. However, animal numbers and statistical power were low in this experiment and further research is necessary to confirm whether the opioid system is involved in the formation of judgement biases.

BackgroundLow food availability leading to reductions in Body Condition Score (BCS; 0 indicates emaciation and 5 obesity) in sheep often coincides with low temperatures associated with the onset of winter in New Zealand. The ability to adapt to reductions in environmental temperature may be impaired in animals with low BCS, in particular during pregnancy when metabolic demand is higher. Here we assess whether BCS affects a pregnant animal's ability to cope with cold challenges.MethodsEighteen pregnant ewes with a BCS of 2.7±0.1 were fed to attain low (LBC: BCS2.3±0.1), medium (MBC: BCS3.2±0.2) or high BCS (HBC: BCS3.6±0.2). Shorn ewes were exposed to a 6-h acute cold challenge in a climate-controlled room (wet and windy conditions, 4.4±0.1°C) in mid-pregnancy. Blood samples were collected during the BCS change phase, acute cold challenge and recovery phase.ResultsDuring the BCS change phase, plasma glucose and leptin concentrations declined while free fatty acids (FFA) increased in LBC compared to MBC (P<0.01, P<0.01 and P<0.05, respectively) and HBC ewes (P<0.05, P<0.01 and P<0.01, respectively). During the cold challenge, plasma cortisol concentrations were lower in LBC than MBC (P<0.05) and HBC ewes (P<0.05), and FFA and insulin concentrations were lower in LBC than HBC ewes (P<0.05 and P<0.001, respectively). Leptin concentrations declined in MBC and HBC ewes while remaining unchanged in LBC ewes (P<0.01). Glucose concentrations and internal body temperature (T(core)) increased in all treatments, although peak T(core) tended to be higher in HBC ewes (P<0.1). During the recovery phase, T4 concentrations were lower in LBC ewes (P<0.05).ConclusionEven though all ewes were able to increase T(core) and mobilize glucose, low BCS animals had considerably reduced cortisol and metabolic responses to a cold challenge in mid-pregnancy, suggesting that their ability to adapt to cold challenges through some of the expected pathways was reduced.

The affective states of animals are important determinants of welfare, yet they are poorly understood. Here we investigate opioid involvement in the regulation of behaviours that may be indicative of the arousal and valence components of affective states in sheep. Ewes treated with sterile water (C), a low or high dose of the opioid agonist morphine (M1, M2) or opioid antagonist naloxone (N1, N2; n=8 per treatment) were exposed to a range of different situations, including availability of concentrate feed, grazing in a paddock, novel object test and isolation box test; behavioural indicators, activity and ear postures were assessed. Morphine treated ewes crossed more zones (78.1±5.4 for M1, P=0.025 and 99.3±5.4 for M2, P=0.01) compared to C ewes (37.3±5.4) and vocalized more (49.9±6.5 for M1, P<0.001 and 43.2±6.5 for M2, P=0.005) compared to C ewes (9.7±6.5) during the novel object test. Morphine treated ewes also attempted to escape more often (3.7±0.6 for M1, P=0.01 and 4.3±0.6 for M2, P<0.001) compared to C ewes (0.7±0.6) and showed a higher duration of the backward ear posture (14.9±2.0s for M1, P=0.02) compared to C ewes (6.1±2.0s) during the novel object test. While grazing, morphine treated ewes (M1, P=0.025 and M2, P<0.001) also walked more compared to compared to C ewes. Opioid treatment did not affect agitation during the isolation test. Concentrate feed intake (square-rootg) was slightly reduced in the N2 ewes (3.6±0.9, P=0.02) compared to the C ewes (6.6±0.9) at 1.5h after injection, while morphine had no effect on intake. In conclusion, morphine had a major impact on activity suggesting that the opioid system may be involved in regulating the arousal component of affective states in sheep. Morphine may have reduced the negative experience in the novel object test as indicated by the higher duration of the backward ear posture; however, further investigation is needed to determine the impact of opioid administration on emotional valence.

The availability of food is a crucial factor determining the health and growth of animals. Prolonged or severe food restriction will trigger the subjective state of hunger, which could potentially reduce welfare. We refined a methodology for the measurement of feeding motivation as an indicator of hunger, evaluated the effects of food restriction on feeding motivation in ewes (Ovis aries) and applied a behavioural demand analysis to the data. Sixteen ewes were exposed to five different cost levels (i.e., 2, 6.6, 12.1, 22, or 40m walking distances per reward) and two feeding levels (24h restriction and an un-restricted control). We found that 24h restricted ewes worked for a higher number of rewards (P<0.001), walked a greater total distance (P<0.001) and approached the feeding station faster on the first visit (P<0.001). Therefore, the methodology was able to detect differences in feeding motivation between restricted and control ewes and is a potential indirect indicator of hunger. A generic demand function fitted to the data showed that the elasticity of demand, the maximum price paid (Pmax) and maximum expenditure (Omax) were not sensitive indicators of motivation, probably because we did not generate a complete demand curve. Imposing a cost by providing sheep with the opportunity to walk for their food could be a valuable tool in establishing acceptable feeding levels from an animals’ perspective. However, more research on validating behavioural demand measures as indicators of motivation is needed.

The current study optimised breeding schemes for litter size (LS), lambing interval (LI), body weight (BW) and gastrointestinal parasite resistance for sheep in Kenya. Selection for the breeding goal traits was performed in a conventional way using information on phenotypes only. For gastrointestinal parasite resistance, information on genetic makers was used, with faecal egg count (FEC) as an indicator trait. Selection for parasite resistance was partly based on field measurements and the possibilities for marker-assisted selection (MAS) were explored. Several selection schemes were defined based on whether a classical selection only was used (Latin number 1), a quantitative trait loci (QTL) for FEC was assumed to be available (2), that the correlation between FEC and BW was assumed to be positive (unfavourable-Roman I) or negative (favourable- II) and finally how FEC was included in the index (i.e., no inclusion (A), with FEC (B) or with FEC QTL (C-F)). The schemes with overlapping generations were evaluated using the computer program SelAction. Rams, ewes and total selection responses in US dollars ($) per animal, and rams' and ewes' accuracies for each scheme with a favourable or unfavourable correlation were estimated. The differences in total selection responses between schemes that did not include FEC in the selection index resulted in a response of $0.16 in scheme 1AI and $0.20 in scheme 1AII. In schemes 1BI and 1BII, FEC was included in the index. The responses in scheme 1BI and 1BII were $0.165 and $0.217, respectively. The increase in response in schemes II compared with schemes I was due to a favourable correlation between BW and FEC. The different FEC index traits had a different effect on economic response. It should be noted that increased emphasis on selection for FEC will reduce the relative responses to the breeding goal traits BW, LS and LI. Consequently, the goal of selection for FEC should be to maintain acceptable levels of gastro-intestinal parasite resistance as well as sufficient improvement of LS and BW.