Elena Nalon

Mechanical nociception thresholds in lame sows: Evidence of hyperalgesia as measured by two different methods

Lameness is a frequently occurring, painful condition of breeding sows that may result in hyperalgesia, i.e., an increased sensitivity to pain. In this study a mechanical nociception threshold (MT) test was used (1) to determine if hyperalgesia occurs in sows with naturally-occurring lameness; (2) to compare measurements obtained with a hand-held probe and a limb-mounted actuator connected to a digital algometer; and (3) to investigate the systematic left-to-right and cranial-to-caudal differences in MT. Twenty-eight pregnant sows were investigated, of which 14 were moderately lame and 14 were not lame. Over three testing sessions, repeated measurements were taken at 5 min intervals on the dorsal aspects of the metatarsi and metacarpi of all limbs. The MT was defined as the force in Newtons (N) that elicited an avoidance response, and this parameter was found to be lower in limbs affected by lameness than in normal limbs (P<0.05). Forelimbs had higher MTs than hindlimbs (P<0.001). The hand-held probe systematically yielded lower values than the actuator (P<0.001), and the MT differed between morning and afternoon testing sessions (P<0.001), as well as between days (P<0.001). The findings provide evidence that lame sows experience hyperalgesia. Systematic differences between forelimb and hindlimb MT must be taken into account when such assessments are performed.

Effect of locomotion score on sows’ performances in a feed reward collection test

Sows housed in groups have to move through their pen to fulfil their behavioural and physiological needs such as feeding and resting. In addition to causing pain and discomfort, lameness may restrict the ability of sows to fulfil such needs. The aim of our study was to investigate the extent to which the mobility of sows is affected by different degrees of lameness. Mobility was measured as the sows willingness or capability to cover distances. Feed-restricted hybrid sows with different gait scores were subjected to a feed reward collection test in which they had to walk distances to obtain subsequent rewards. In all, 29 group-housed sows at similar gestation stage (day 96.6 ± 7 s.d.) were visually recorded for gait and classified as non-lame, mildly lame, moderately lame or severely lame. All sows received 2.6 kg of standard commercial gestation feed per day. The test arena consisted of two feeding locations separated from each other by a Y-shaped middle barrier. Feed rewards were presented at the two feeders in turn, using both light and sound cues to signal the availability of a new feed reward. Sows were individually trained during 5 non-consecutive days for 10 min/day with increasing barrier length (range: 0 to 3.5 m) each day. After training, sows were individually tested once per day on 3 non-consecutive days with the maximum barrier length such that they had to cover 9.3 m to walk from one feeder to the other. The outcome variable was the number of rewards collected in a 15-min time span. Non-lame and mildly lame sows obtained more rewards than moderately lame and severely lame sows (P<0.01). However, no significant difference was found between non-lame and mildly lame sows (P=0.69), nor between moderately lame and severely lame sows (P=1.00). This feed reward collection test indicates that both moderately lame and severely lame sows are limited in their combined ability and willingness to walk, but did not reveal an effect of mild lameness on mobility. These findings suggest that moderately and more severely lame sows, but not mildly lame sows, might suffer from reduced access to valuable resources in group housing systems.

Fluctuation of potential zinc status biomarkers throughout a reproductive cycle of primiparous and multiparous sows.

Fluctuations in Zn metabolism throughout gestation and lactation might affect Zn requirements. However, scientific data on Zn requirements for breeding sows are limited. The objective of the present study was to assess the Zn status of primiparous and multiparous sows using different Zn status biomarkers, to identify periods of critical Zn status throughout the reproductive cycle at different parities. Blood samples were taken after overnight fasting before feeding in the morning from five primiparous and ten multiparous sows at fixed time intervals during gestation (days - 5, 0 (insemination), 21, 42, 63 and 84), around parturition (days 108, 112, 115 (parturition) and 118) and during lactation (days 122, 129 and 143 (weaning)). At parturition, blood samples were collected from two randomly selected piglets per sow before colostrum intake. Plasma was analysed for Zn and Cu contents, whereas serum was analysed for alkaline phosphatase, metallothionein and albumin concentrations. Independently of parity, all biomarkers fluctuated differently during gestation and lactation (P< 0·050). This reflects their different roles in Zn metabolism, and suggests that the choice of a Zn status biomarker necessitates careful consideration. Low average plasma Zn concentration at the end of gestation and throughout lactation seem to be replenished towards weaning.

Willingness to walk for a feed reward in lame and non-lame sows

The aim of this study was to investigate the role of coprophagous behavior in suckling rabbit on the implantation of caecal microbiota and to try improving the health status of rabbits modifying this behavior. Three groups were compared: in FM group (n=24 litters), pups had free access to maternal hard feces, in NF group (n=28), ingestion of hard feces was prevented, and in FF group (n=28), pups had access only to hard feces excreted by foreign females (n = 5, 7 and 9 feces from 2 to 13 d, 14 to 17 d, 18 to 20 d, respectively). Pup mortality, excretion and ingestion of feces were measured daily. Bacterial composition was assessed by 454 pyrosequencing of the V3-V4 region of 16S RNA genes at 14, 35, 49 and 80 d of age. The total number of feces excreted by the does from 2 to 20 d after delivery ranged widely, but was similar among groups (16.1 ± 12.6 feces doe-1). Ingestion of feces was 3 times greater in FF than in FM group (35.6 vs 9.9, p < 0.001). From 1 to 80 d of age the FF and NF groups exhibited respectively the lowest (9.3%) and highest (22.8%) pup mortality compared to FM group (15.5 %, p = 0.03). At age 14 d the caecal bacterial community was dominated by Bacteroidetes phyla (63.3%), Bacteroidaceae family (36.0%) and Bacteriodes genus (36.0%). With increasing age, Firmicutes phyla, Lachnospiraceae and Ruminococcaceae families became the dominant taxa (92.0%, 44.0 % and 37.9 %, respectively at 80 d of age). Impairment of feces ingestion delayed this ecological succession, with greater and lower relative abundance of Bacteroidaceae and Ruminococcaceae respectively in NF than the two other groups at age 35 d (p < 0.1). In conclusion, the coprophagous behaviour of suckling rabbits is implicated in the maturation of caecal bacterial microbiota and stimulation of this natural behavior improve the health status of animals and could be used to limit the use of antibiotics.Equitherapy is widely practiced and its positive effects are quite well known. However, dynamics of communication between the horse, the user and the therapist is little described. Here, we proposed a pilot study that focused on visual attention of these three partners at two moments: before and during horseback riding (HR). The triad had been observed during the equitherapy session (around 45 min) of four boys with autism (6-9 yo). Ten-second scan samplings recorded the gaze direction of each subject. Data were converted in percentage of time. Horses had mostly gazed at physical environment both before (76.2±6.6%) and during (91.6±1.6%) HR. Human they mostly gazed was the therapist before HR (8.7±3.3%). Similarly, boys mostly gazed at physical environment throughout the session (61.7±17.1% and 46.9±15.3%, respectively). Focus on social partner showed that boys mostly gazed at horse especially during HR (8.7±4.7% and 13.2±9.6% respectively). Likewise their visual attention to humans was enhanced during HR (9.0±1.5% to 19.3±3.1%). At last, before HR, therapists mostly gazed at boy (33.8±9.4%) and horse (38.4±16.7%). During HR, their attention on boy increased slightly (36.7±10.0%) but surprisingly, their attention on horse decreased extremely (7.2±0.9%) in favor of the physical environment (26.1±11.5% to 50.3±12.7%). This pilot study on visual attention during equitherapy suggested that children with autism, whose attentional skills are impaired, seemed to be more attentive to social partners during HR. In this situation, horses seemed few attentive to humans that might be explain by either apathy or working situation. Finally, the reduction of therapist’s visual attention to the horse during HR suggests a decrease in vigilance. This was an example of routine where human pays less attention to animal, which constituted one of the most accidental situations. Thus, therapists must be greatly attentive when horses are used in such therapeutic programs where safety is indispensable.Similar farrowing progress among sows housed in crates and pens Pedersen, Janni Hales; Moustsen, V. A.; Devreese, Anne Michéle; Hansen, Christian Fink Published in: European Association for Animal Production. Annual Meeting. Book of Abstracts DOI: 10.3920/978-90-8686-782-0 Publication date: 2013 Document Version Early version, also known as pre-print Citation for published version (APA): Pedersen, J. H., Moustsen, V. A., Devreese, A. M., & Hansen, C. F. (2013). Similar farrowing progress among sows housed in crates and pens. DOI: 10.3920/978-90-8686-782-0The EAAP AFWG was constituted in 2007 with a view t o enhancing the role of animal fibre in EU27, utilizing an approach based on science and technology. Although an unrecorded and neglected product, annual production of wool from 6 2m breeding sheep (Eurostat) alone is substantial at an estimated 186,000 tonnes (FAO). R ecent outputs include organised symposia and publications defining current knowledge. In rec ognising the need for better networks of scientists and technologists, a total of 5 applicat ions for financial support has been made to the EC COST Framework since 2010. Such applications , by initial pre-proposal, are assessed in 6 categories with a maximum score of 6 for each, giving a maximum score of 36. Preproposals scoring most highly, on average, are invi ted to submit a full proposal. Evaluation has been characterised by large variation in scores of individual assessors. For one example, scores of 36, 33, 32, 32, 28, 21,16 were awarded by 7 assessors, giving mean value = 28.3; SD = 7.23; CV%= 25.5. The divergence of the median v lue of 32 from the mean (28.3) shows a skewed distribution. Removal of the two low est outliers, gives a mean = 32.2; SD= 2.86; CV%= 8.9 and median = 32 and removes the skew . The use in ranking, of such a simple average of means, is clearly unreliable. Another ex ample, with a mean score of 31.25, gave rise to an invitation to submit a full proposal. Th is was done, involving 14 EU partner, and 4 international “reciprocal agreement”, countries. Th e outcome of this application was a score of 53, and below the cut-off score of 55, for furth er progression. The consensus conclusion of evaluation was that “the expected benefits are like ly to be non-European”. This conclusion is surprising and essentially without explanation. The selection of evaluators remains a concern. 64 th EAAP Annual meeting, 25-30 August, 2013, Nantes, France Symposium on South American Camelids and other Fibre AnimalsThe role of the agouti gene in white phenotype was explored in mice. The agouti signalling protein (ASP) can inhibit the differentiation of melanoblasts through the inhibition of the alfa-MSH-induced expression of microphtalmia (MITF) and its binding to a M box regulatory element. The level of microphtalmia in the cells is reduced. To investigate the role of agouti in this phenotype we characterised the transcript structures an relative mRNA expression levels in 13 white alpaca. The reverse transcription analysis of mRNA purified from skin biopsies revealed the presence of three transcripts with different 5’untranslated regions (UTRs) and color specific expression. One of the transcripts, possibly originating from a duplication event (intra-chromosomal recombination) of the agouti gene is characterised by a 5’UTR containing 142 bp of the NCPOA6 gene sequence. Furthermore, the raltive level expression analysis of mRNA demonstrates that the agouti gene has upregulated expression in white skin, suggesting a pleiotropic effect of agouti gene in the white phenotype. Resumen : Recombinacion cromosomica del gen agouti en alpacas blancas. Fue explorado en ratones el rol del gen agouti en el fenoripo blanco. La protein senalarizadora agouti (ASP) puede inibir la diferenciacion de los melanoblastos a traves de la inhibicion de la expresion alfa-MSH inducida de macroftalmia (MITF) y su union al elemento regulador Mbox. El nivel de macroftalmia en las celulas se reduce. Para investigar el rol del agouti en este fenotipo, caracterizamos las estructuras transcriptas a una relativa expresion del mRNA en 13 alpacas blancas blancas. El analisis de transcripcion reversa del mRNA purificado a partir de las biopsias de piel, revelaron la presencia de tres transciptos con diferentes regiones no traducidas del extremo 5’ (5’UTR) y expresiones de color especificas. Uno de los transcriptos, posiblemente procedente de un evento de duplicacion (recombinacion intra-cromosomico) del gen aguti se caracteriza por un 5’ UTR que contiene 142 pb del gen NCPOA6. Por otra parte, el analisis del nivel relativo de expresion del mRNA demuestra que el gen agouti tiene sobre expresion reguladora en piel blanca, lo que sugiere un efecto pleiotropico del gen agouti en el fenotipo blanco.The agouti gene encodes agouti signalling protein (ASIP) whic h regulates pheomelanin and eumelanin synthesis in mammals. To investigate the role of agouti in coat color variation of alpaca, we characterised the agouti gene on 27 black and 12 brown alpaca. The exon-4 hosts three loss-of-function recessive mutations: g.3836C >T, g.3896G>A and g.3866_3923del57, involved in eumelanin synthesis. The deletion at th e position p.C109-Rdel19 eliminates the two beta sheets and the R-F-F- motif from the agout i functional domain, which are essential against alfa-MSH. Therefore, the deleted allele app ears to lose function. The other ANPs observed at the amino acid position 98 and 118 chan ge the conserved R to C and the R-F-Fmotif into H-F-F-. The R-F-F- motif is important fo r functioning at MCRs; the disruption of this motif may result in a non functional agouti pr otein since the alteration of residues in and around R-F-F- causes a decrease in agouti protein i nhibition of alfa-MSH binding to MCRs during signal transduction. The three mutations are randomly distributed among the black alpaca. In our sample, we observed two genotypes : g.3836C>T/g.3896G>A (10 animals) and g.3836C>T/g.3866_3923del57 (17 animals). Among the brown alpaca, 2 are homozygous for the wild allele, 12 are heterozygous for g.3896G>A mutation, carriers for black phenotype.

Marginal dietary zinc concentration affects claw conformation measurements but not histological claw characteristics in weaned pigs

The aim of the present study was to explore whether marginal dietary zinc (Zn) concentrations affect claw quality measurements in weaned pigs. Twenty-four weaned pigs were randomly assigned to two dietary treatment groups: (1) 42 mg Zn/kg diet from ingredients only (unsupplemented, marginal dietary Zn concentration below Zn requirements of 80 mg Zn/kg feed); and (2) 106 mg Zn/kg diet, where Zn was added as ZnO (common commercial dietary Zn concentration). Claw conformation characteristics were measured at the start (day 0, 4 weeks of age) and at the end (day 36) of the study, and the histological claw characteristics of horn wall and heel horn were examined on samples collected at 9 weeks of age. Non-supplemented pigs had narrower claw widths (P= 0.028) and lower toe heights (P= 0.010) at 9 weeks. The length of the dorsal border tended to be lower for the non-supplemented piglets (P= 0.092). Claw volume and claw horn size were lower (P= 0.003 and P < 0.001, respectively) for the non-supplemented pigs at 9 weeks of age. Horn growth and wear were lower for the non-supplemented pigs (P= 0.044 and P < 0.001, respectively), but net horn growth (horn growth minus wear) was not different (P= 0.406). No changes in the histological claw characteristics were observed. Differences in claw quality measurements were found between lateral and medial claw digits and between fore and hind claws. It was concluded that marginal dietary Zn concentration affected various claw quality measurements. Marginal dietary Zn concentrations may not be sufficient to maintain claw quality in pigs.

Impact of parity on bone metabolism throughout the reproductive cycle in sows

Bone metabolism fluctuates throughout the reproductive cycle of sows to enable foetal growth and milk production. Although increased bone mineralisation is conceivable in sows during reproduction, a study of mineralisation in function of parity has not been performed. This study evaluated the fluctuations of markers for bone metabolism in primiparous and multiparous sows throughout a reproductive cycle. The experiment included ten multiparous and five primiparous commercial hybrid sows from one herd. The sows were monitored for one reproductive cycle and fed according to commercial dietary standards. Blood samples were taken in the morning before feeding at fixed time intervals before (day -5) and during gestation (insemination (day 0), 21, 42, 63, 84), around parturition (day 108, 112, parturition (115), 118), and during lactation (day 122, 129, 143). Serum osteocalcin (OC) concentration increased in early and mid-gestation (P=0.002) and decreased at the end of gestation (P=0.001), whereas crosslaps (CTX) concentration decreased during early and mid-gestation (P=0.002) and increased towards the end of gestation (P=0.001). Towards the end of lactation serum levels of both markers increased (P=0.007 and 0.013, respectively). For hydroxyproline (HYP) no significant fluctuation in function of the reproductive cycle was detected. Matrix metalloproteinase 2 (MMP2) concentration increased towards parturition for both primiparous and multiparous sows (P=0.001), whereas during lactation no significant fluctuations in function of the reproductive cycle were found. A parity effect was found for OC and CTX (P<0.010), but not for the other markers. These results demonstrate that bone metabolism differed between primiparous and multiparous sows, although in both groups a similar fluctuation throughout the reproductive cycle was observed.

Inter- and intra-observer repeatability of three locomotion scoring scales for sows

The aim of this study was to investigate the role of coprophagous behavior in suckling rabbit on the implantation of caecal microbiota and to try improving the health status of rabbits modifying this behavior. Three groups were compared: in FM group (n=24 litters), pups had free access to maternal hard feces, in NF group (n=28), ingestion of hard feces was prevented, and in FF group (n=28), pups had access only to hard feces excreted by foreign females (n = 5, 7 and 9 feces from 2 to 13 d, 14 to 17 d, 18 to 20 d, respectively). Pup mortality, excretion and ingestion of feces were measured daily. Bacterial composition was assessed by 454 pyrosequencing of the V3-V4 region of 16S RNA genes at 14, 35, 49 and 80 d of age. The total number of feces excreted by the does from 2 to 20 d after delivery ranged widely, but was similar among groups (16.1 ± 12.6 feces doe-1). Ingestion of feces was 3 times greater in FF than in FM group (35.6 vs 9.9, p < 0.001). From 1 to 80 d of age the FF and NF groups exhibited respectively the lowest (9.3%) and highest (22.8%) pup mortality compared to FM group (15.5 %, p = 0.03). At age 14 d the caecal bacterial community was dominated by Bacteroidetes phyla (63.3%), Bacteroidaceae family (36.0%) and Bacteriodes genus (36.0%). With increasing age, Firmicutes phyla, Lachnospiraceae and Ruminococcaceae families became the dominant taxa (92.0%, 44.0 % and 37.9 %, respectively at 80 d of age). Impairment of feces ingestion delayed this ecological succession, with greater and lower relative abundance of Bacteroidaceae and Ruminococcaceae respectively in NF than the two other groups at age 35 d (p < 0.1). In conclusion, the coprophagous behaviour of suckling rabbits is implicated in the maturation of caecal bacterial microbiota and stimulation of this natural behavior improve the health status of animals and could be used to limit the use of antibiotics.Equitherapy is widely practiced and its positive effects are quite well known. However, dynamics of communication between the horse, the user and the therapist is little described. Here, we proposed a pilot study that focused on visual attention of these three partners at two moments: before and during horseback riding (HR). The triad had been observed during the equitherapy session (around 45 min) of four boys with autism (6-9 yo). Ten-second scan samplings recorded the gaze direction of each subject. Data were converted in percentage of time. Horses had mostly gazed at physical environment both before (76.2±6.6%) and during (91.6±1.6%) HR. Human they mostly gazed was the therapist before HR (8.7±3.3%). Similarly, boys mostly gazed at physical environment throughout the session (61.7±17.1% and 46.9±15.3%, respectively). Focus on social partner showed that boys mostly gazed at horse especially during HR (8.7±4.7% and 13.2±9.6% respectively). Likewise their visual attention to humans was enhanced during HR (9.0±1.5% to 19.3±3.1%). At last, before HR, therapists mostly gazed at boy (33.8±9.4%) and horse (38.4±16.7%). During HR, their attention on boy increased slightly (36.7±10.0%) but surprisingly, their attention on horse decreased extremely (7.2±0.9%) in favor of the physical environment (26.1±11.5% to 50.3±12.7%). This pilot study on visual attention during equitherapy suggested that children with autism, whose attentional skills are impaired, seemed to be more attentive to social partners during HR. In this situation, horses seemed few attentive to humans that might be explain by either apathy or working situation. Finally, the reduction of therapist’s visual attention to the horse during HR suggests a decrease in vigilance. This was an example of routine where human pays less attention to animal, which constituted one of the most accidental situations. Thus, therapists must be greatly attentive when horses are used in such therapeutic programs where safety is indispensable.Similar farrowing progress among sows housed in crates and pens Pedersen, Janni Hales; Moustsen, V. A.; Devreese, Anne Michéle; Hansen, Christian Fink Published in: European Association for Animal Production. Annual Meeting. Book of Abstracts DOI: 10.3920/978-90-8686-782-0 Publication date: 2013 Document Version Early version, also known as pre-print Citation for published version (APA): Pedersen, J. H., Moustsen, V. A., Devreese, A. M., & Hansen, C. F. (2013). Similar farrowing progress among sows housed in crates and pens. DOI: 10.3920/978-90-8686-782-0The EAAP AFWG was constituted in 2007 with a view t o enhancing the role of animal fibre in EU27, utilizing an approach based on science and technology. Although an unrecorded and neglected product, annual production of wool from 6 2m breeding sheep (Eurostat) alone is substantial at an estimated 186,000 tonnes (FAO). R ecent outputs include organised symposia and publications defining current knowledge. In rec ognising the need for better networks of scientists and technologists, a total of 5 applicat ions for financial support has been made to the EC COST Framework since 2010. Such applications , by initial pre-proposal, are assessed in 6 categories with a maximum score of 6 for each, giving a maximum score of 36. Preproposals scoring most highly, on average, are invi ted to submit a full proposal. Evaluation has been characterised by large variation in scores of individual assessors. For one example, scores of 36, 33, 32, 32, 28, 21,16 were awarded by 7 assessors, giving mean value = 28.3; SD = 7.23; CV%= 25.5. The divergence of the median v lue of 32 from the mean (28.3) shows a skewed distribution. Removal of the two low est outliers, gives a mean = 32.2; SD= 2.86; CV%= 8.9 and median = 32 and removes the skew . The use in ranking, of such a simple average of means, is clearly unreliable. Another ex ample, with a mean score of 31.25, gave rise to an invitation to submit a full proposal. Th is was done, involving 14 EU partner, and 4 international “reciprocal agreement”, countries. Th e outcome of this application was a score of 53, and below the cut-off score of 55, for furth er progression. The consensus conclusion of evaluation was that “the expected benefits are like ly to be non-European”. This conclusion is surprising and essentially without explanation. The selection of evaluators remains a concern. 64 th EAAP Annual meeting, 25-30 August, 2013, Nantes, France Symposium on South American Camelids and other Fibre AnimalsThe role of the agouti gene in white phenotype was explored in mice. The agouti signalling protein (ASP) can inhibit the differentiation of melanoblasts through the inhibition of the alfa-MSH-induced expression of microphtalmia (MITF) and its binding to a M box regulatory element. The level of microphtalmia in the cells is reduced. To investigate the role of agouti in this phenotype we characterised the transcript structures an relative mRNA expression levels in 13 white alpaca. The reverse transcription analysis of mRNA purified from skin biopsies revealed the presence of three transcripts with different 5’untranslated regions (UTRs) and color specific expression. One of the transcripts, possibly originating from a duplication event (intra-chromosomal recombination) of the agouti gene is characterised by a 5’UTR containing 142 bp of the NCPOA6 gene sequence. Furthermore, the raltive level expression analysis of mRNA demonstrates that the agouti gene has upregulated expression in white skin, suggesting a pleiotropic effect of agouti gene in the white phenotype. Resumen : Recombinacion cromosomica del gen agouti en alpacas blancas. Fue explorado en ratones el rol del gen agouti en el fenoripo blanco. La protein senalarizadora agouti (ASP) puede inibir la diferenciacion de los melanoblastos a traves de la inhibicion de la expresion alfa-MSH inducida de macroftalmia (MITF) y su union al elemento regulador Mbox. El nivel de macroftalmia en las celulas se reduce. Para investigar el rol del agouti en este fenotipo, caracterizamos las estructuras transcriptas a una relativa expresion del mRNA en 13 alpacas blancas blancas. El analisis de transcripcion reversa del mRNA purificado a partir de las biopsias de piel, revelaron la presencia de tres transciptos con diferentes regiones no traducidas del extremo 5’ (5’UTR) y expresiones de color especificas. Uno de los transcriptos, posiblemente procedente de un evento de duplicacion (recombinacion intra-cromosomico) del gen aguti se caracteriza por un 5’ UTR que contiene 142 pb del gen NCPOA6. Por otra parte, el analisis del nivel relativo de expresion del mRNA demuestra que el gen agouti tiene sobre expresion reguladora en piel blanca, lo que sugiere un efecto pleiotropico del gen agouti en el fenotipo blanco.The agouti gene encodes agouti signalling protein (ASIP) whic h regulates pheomelanin and eumelanin synthesis in mammals. To investigate the role of agouti in coat color variation of alpaca, we characterised the agouti gene on 27 black and 12 brown alpaca. The exon-4 hosts three loss-of-function recessive mutations: g.3836C >T, g.3896G>A and g.3866_3923del57, involved in eumelanin synthesis. The deletion at th e position p.C109-Rdel19 eliminates the two beta sheets and the R-F-F- motif from the agout i functional domain, which are essential against alfa-MSH. Therefore, the deleted allele app ears to lose function. The other ANPs observed at the amino acid position 98 and 118 chan ge the conserved R to C and the R-F-Fmotif into H-F-F-. The R-F-F- motif is important fo r functioning at MCRs; the disruption of this motif may result in a non functional agouti pr otein since the alteration of residues in and around R-F-F- causes a decrease in agouti protein i nhibition of alfa-MSH binding to MCRs during signal transduction. The three mutations are randomly distributed among the black alpaca. In our sample, we observed two genotypes : g.3836C>T/g.3896G>A (10 animals) and g.3836C>T/g.3866_3923del57 (17 animals). Among the brown alpaca, 2 are homozygous for the wild allele, 12 are heterozygous for g.3896G>A mutation, carriers for black phenotype.