Social interactions, cortisol and reproductive success of domestic goats (Capra hircus) subjected to different animal densities during pregnancy

Thermography as an indicator of goat welfare in an intensive production system

This study evaluated the welfare of Saanen, Moxoto, and Anglo-Nubian goats kept in collective or individual pens for a feedlot system, evaluated with infrared thermography. A total of twenty-four goats were used, eight for each breed. Animals were distributed in a completely randomized design, with a 2 × 3 factorial with two fixed effects: housing type (collective or individual pens) and breed (Moxoto, Saanen, and Anglo-Nubian). The surface temperature was evaluated using an infrared thermographic camera, and behavioral analysis was based on the qualitative behavior assessment using a fixed list of descriptors. The breed was not different for all behavior evaluations and surface temperature (p>0.05). There was a difference between the housing types, where the collective pens showed goats more agitated, frustrated, and sociable (p<0.05). There was an influence of agitated, apathetic, frustrated, attentive, and curious behaviors on surface temperatures, in which feet and body temperatures decreased in these goats. (p<0.05). Moxoto, Anglo-Nubian, and Saanen goats showed similar behavior even when kept in collective or individual pens. Individual pens can restrict the goats' social relationships but reduce negative behaviors such as irritation and frustration. The lower foot temperatures of feedlot goats are related to the attention behavior in 86.75% of the observations.

Stocking density, ambient temperature, and group size affectsocial behavior, productivity and reproductivity of goats- A review

The stocking density (animal/area, SD) is one of the significant factors that influence the welfare and performance of animals. However, there are discrepancies in the recommended SD for fiber, meat, and dairy goats, which means farming practices and welfare standards for goats should be better defined. Therefore, this review article sheds light on 1) some differences between goats and sheep. 2) the geographical distribution of fiber, meat type, and dairy goat populations. 3) effects of interaction between SD and group size on social, feeding, and aggressive behaviors. 4) the effects of SD on meat and milk production. 5) the relationship between SD and reproductive performance. In conclusion, the larger space allowance with access to an outdoor yard can improve species-specific behaviors and meat and milk yield. Moreover, goats are more sensitive to high SD (less than 3 m²/ goat), especially during the last stage of the gestation period. Allowing optimal floor space for each breed is important to avoid the undesired behavioral response. Conclusively, improving the housing aspects, including floor space and enrichment tools, would assist in implementing welfare-economic production standards for goats.

A Brief Update on the Challenges and Prospects for Goat Production in Mexico

In Mexico, information on goat production is scarce and documenting goat production challenges and future perspectives could be of great value, not only for Latin America, but also for international players—including those from farms, industry, and academia. Therefore, the objective of this review is to provide current knowledge on goat production systems in Mexico and discuss current challenges and future perspectives for this animal production sector. In Mexico, more than 70% of goats are produced under extensive production systems in arid and semi-arid areas and roughly 25% are produced in intensive or semi-intensive systems. Main breeds are French Alpine, Saanen, Toggenburg, LaMancha, Nubian, Boer, and their crosses. The main challenges are correlated at different levels, where economic, social, and environmental issues are mixed and are closely associated with goat health and welfare. Newly available farming technologies could be an option that should be explored. Mexican goat farming systems will need to look at the animal, social, and environmental factors to promote sustainable production systems.

Feeding, Resting and Agonistic Behavior of Pregnant Boer Goats in Relation to Feeding Space Allowance

The aim of this study was to test the effect of the animal to feeding place ratio on behavior of meat goats during gestation. In one group (FP-1.0; n=10) every goat had a single feeding place while in the other group (FP-0.5; n=10) two goats had to share one feeding place. Behaviors were analyzed with the continuous sampling method for 24 h for each animal. Social dominance index was used by ranking individuals as low-, medium- and high-ranking according to withdrawal and displacement behaviors. Total daily feeding duration decreased (P=0.001) from 5.2 h to 4.2 h by reducing feeding place. Feeding duration was neither affected by social rank (P=0.362) nor its interaction with feeding place (P=0.159). Feeding frequency was higher in FP-0.5 than FP-1.0 (P=0.001). Low-ranking goats had a higher feeding frequency (P<0.001). Resting duration (lying and standing) decreased in medium- and low-ranking goats in FP-0.5 (P=0.001) while all rank categories were similar in FP-1.0. Competition behaviors increased (P=0.001) in medium- and low-ranked goats in FP-0.5 but were similar between rank categories in FP-1.0. Feeding place and social rank had an effect (P≤0.009) on some of the agonistic behaviors. Agonistic interactions such as displacement, butting and ignoring were affected by the interaction of feeding place and social rank (P≤0.005). In conclusion, the reduction of the number of feeding places from 1.0 to 0.5 per goat in pregnant hornless Boer goats negatively affected feeding, competition, resting and aggressive behaviors, whereas low-ranking animals suffered more from competition and aggression behaviors.

Search Behavior in Goat (Capra hircus) Kids From Mothers Kept at Different Animal Densities Throughout Pregnancy

Individual differences in cognitive performance are often reported but factors related to variation within species are rarely addressed. Goats (Capra hircus) have been subjects of many cognitive studies recently but without focus on individual variation. Among others, factors such as prenatal stress and sex of the individual have been proposed as possible explanations for individual variation in cognitive skills. We aimed to study whether prenatal environment, prenatal stress, litter size, sex, and birth weight influences search behavior skills of goat kids. Pregnant Norwegian dairy goats were exposed to different spatial allowance (namely 1.0, 2.0, or 3.0 m2 per animal) within the commercially applied range during pregnancy and their serum cortisol levels were measured six times within this period. Twenty-six of the kids born entered a three-stage searching task with increasing difficulty when they were 6 weeks old. The tasks included finding a bucket of milk: while moving (stage 1), after moving and disappearing behind a curtain (stage 2), and moving behind a displacement device and the device moving behind a curtain while hiding the bucket (stage 3). We found that prenatal animal density had no effect on the search skills of the offspring, while kids with higher prenatal maternal cortisol levels performed better at the highest stage tested: finding an object after single invisible displacement. At this stage, singleton kids and males performed better than twins and females. Birth weight had no effect at this stage. The findings suggest that maternal cortisol in the observed range had a facilitating effect on cognitive development of goat kids.

Effects of crowding and water restriction stress on creole goat reproduction in the Oaxacan Sierra Mixteca, Mexico

Chronic stress disrupts reproductive efficiency. Yet, the manner in which stress disturbs reproduction in goats is currently unknown. The Oaxacan Mixteca region is one of Mexico's poorest, with high levels of deforestation, high ambient temperatures, and lack of water. Native goats of the Oaxacan Mixteca Region live in these stressful conditions, as well as in overcrowded and water restricted conditions. Therefore, the aim of this study was to evaluate the effects of these very stressful conditions on the reproduction of male and female goats. Control group was uncrowded, with daily water supply; stress group was overcrowded, with water restriction. The study was conducted from September 2015 to February 2016; the expression of reproductive behaviour and variations of cortisol levels were assessed. In females, oestradiol and progesterone were evaluated during the oestrous cycle. In males, testosterone levels were evaluated before and during reproductive activity. Sexual behaviour decreased in stressed goats: approaching, tail swishing, urination, vaginal discharge and flank contraction decreased in stressed females. Anogenital sniffing, licking, Flehmen reflex, bleating, mount attempts and mounts decreased in male goats. Cortisol levels in stressed animals were higher compared with control animals. Oestradiol and Progesterone levels in stressed females were significantly lower during the follicular and luteal phase, respectively, compared with control females. Testosterone levels in stressed males were lower than in control males, both before and during reproduction. These results indicate that even though goats from the Oaxacan Mixteca Region are habituated to their environmental conditions, they are still stressed by them, as shown by a higher activation of the adrenal axis in stressed goats than in control goats. High cortisol levels may induce low oestradiol levels in females and low testosterone levels in males, as well as a disruption in the expression of their reproductive behaviour.

Effect of repeated adrenocorticotropic hormone administration on reproductive function and hair cortisol concentration during the estrous cycle in goats

Measurement of the cortisol concentration in hair has been used as an index of chronic stress in several species including humans, wildlife and domestic animals. However, how accurately the cortisol concentration in hair reflects the changes in circulating cortisol concentrations has not been well documented. The objective of the present study was to examine the effect of repeated adrenocorticotropic hormone (ACTH) administration on the reproductive function during the estrous cycle and hair cortisol concentrations in goats. In experiment 1, goats were administered ACTH (0.625 IU/10 kg of body weight, n = 6) or saline (n = 6) intramuscularly once a day for 7 days on Day 11-17 of the estrous cycle (day 0 was the day of ovulation). In experiment 2, goats were administered ACTH (0.625 IU/10 kg of body weight, n = 6) or saline (n = 6) intramuscularly twice a day on Day 11-24 of the estrous cycle. Blood samples were collected 0, 0.5, and 6 h after first administration to determine the circulating cortisol concentrations. Hair was clipped at 0, 1, and 2 months after the start of administration. In both experiments, the plasma cortisol concentration increased at 0.5 h and returned to baseline at 6 h after ACTH administration. During the experiments, estrus was observed in most animals in ACTH and saline groups (6/6 and 4/6 in experiment 1 and 5/6 and 6/6 in experiment 2, respectively) and ovulation was observed in all goats examined. However, the number of ovulatory follicles was significantly different between the ACTH and saline groups, and the maximal diameter of ovulatory follicles tended to be different (P = .07) between the ACTH and saline groups. In experiment 1, the hair cortisol concentration was not influenced by the ACTH administration throughout the sampling period. In experiment 2, the hair cortisol concentration in the ACTH group was greater at 1 month after administration than the pre-administration value, but was not significantly different at 2 months. These results suggest that repeated ACTH administration affects the development and ovulatory process of ovarian follicles and analysis of the hair cortisol concentration can be used for assessing relatively long-term changes in cortisol concentration in the circulation.

Density-Dependent Spacing Behaviour and Activity Budget in Pregnant, Domestic Goats (Capra hircus)

Very little is known about the spacing behaviour in social groups of domestic goats (Capra hircus) in the farm environment. In this experiment, we studied interindividual distances, movement patterns and activity budgets in pregnant goats housed at three different densities. Norwegian dairy goats were kept in stable social groups of six animals throughout pregnancy at 1, 2 or 3 m² per individual and their spacing behaviours (i.e. distance travelled, nearest and furthest neighbour distance) and activity budgets (e.g. resting, feeding, social activities) were monitored. Observations were made in the first, second and last thirds of pregnancy in the mornings, at noon and in the afternoons of each of these phases (4.5 hours per observation period). The findings show that goats held at animal densities of 2 and 3 m² moved longer distances when they had more space per animal and kept larger nearest and furthest neighbour distances when compared to the 1 m² per animal density. Less feeding activity was observed at the high animal density compared to the medium and low density treatments. The phase of gestation also had an impact on almost all behavioural variables. Closer to parturition, animals moved further distances and the increase in nearest and furthest neighbour distance was more pronounced at the lower animal densities. During the last period of gestation, goats spent less time feeding and more on resting, social behaviours and engaging in other various activities. Our data suggest that more space per goat is needed for goats closer to parturition than in the early gestation phase. We concluded that in goats spacing behaviour is density-dependent and changes with stages of pregnancy and activities. Finally, the lower density allowed animals to express individual preferences regarding spacing behaviour which is important in ensuring good welfare in a farming situation.

Transcriptome analysis of the Capra hircus ovary

BACKGROUND

Capra hircus is an important economic livestock animal, and therefore, it is necessary to discover transcriptome information about their reproductive performance. In this study, we performed de novo transcriptome sequencing to produce the first transcriptome dataset for the goat ovary using high-throughput sequencing technologies. The result will contribute to research on goat reproductive performance.

METHOD AND RESULTS

RNA-seq analysis generated more than 38.8 million clean paired end (PE) reads, which were assembled into 80,069 unigenes (mean size = 619 bp). Based on sequence similarity searches, 64,824 (60.6%) genes were identified, among which 29,444 and 11,271 unigenes were assigned to Gene Ontology (GO) categories and Clusters of Orthologous Groups (COG), respectively. Searches in the Kyoto Encyclopedia of Genes and Genomes pathway database (KEGG) showed that 27,766 (63.4%) unigenes were mapped to 258 KEGG pathways. Furthermore, we investigated the transcriptome differences of goat ovaries at two different ages using a tag-based digital gene expression system. We obtained a sequencing depth of over 5.6 million and 5.8 million tags for the two ages and identified a large number of genes associated with reproductive hormones, ovulatory cycle and follicle. Moreover, many antisense transcripts and novel transcripts were found; clusters with similar differential expression patterns, enriched GO terms and metabolic pathways were revealed for the first time with regard to the differentially expressed genes.

CONCLUSIONS

The transcriptome provides invaluable new data for a functional genomic resource and future biological research in Capra hircus, and it is essential for the in-depth study of candidate genes in breeding programs.

The effects of prenatal stocking densities on the fear responses and sociality of goat (Capra hircus) kids

Prenatal stress (stress experienced by a pregnant mother) and its effects on offspring have been comprehensively studied but relatively little research has been done on how prenatal social stress affects farm animals such as goats. Here, we use the operational description of ‘stress’ as “physical or perceived threats to homeostasis.” The aim of this study was to investigate the prenatal effects of different herd densities on the fear responses and sociality of goat kids. Pregnant Norwegian dairy goats were exposed to high, medium or low prenatal animal density treatments throughout gestation (1.0, 2.0 or 3.0 m² per animal, respectively). One kid per litter was subjected to two behavioral tests at 5 weeks of age. The ‘social test’ was applied to assess the fear responses, sociality and social recognition skills when presented with a familiar and unfamiliar kid and the ‘separation test’ assessed the behavioral coping skills when isolated. The results indicate goat kids from the highest prenatal density of 1.0 m² were more fearful than the kids from the lower prenatal densities (i.e. made more escape attempts (separation test: P < 0.001) and vocalizations (social test: P < 0.001; separation test: P < 0.001). This effect was more pronounced in females than males in the high density (vocalizations; social test: P < 0.001; separation test: P  =  0.001) and females were generally more social than males. However, goat kids did not differentiate between a familiar and an unfamiliar kid at 5 weeks of age and sociality was not affected by the prenatal density treatment. We conclude that high animal densities during pregnancy in goats produce offspring that have a higher level of fear, particularly in females. Behavioral changes in offspring that occur as an effect of prenatal stress are of high importance as many of the females are recruited to the breeding stock of dairy goats.