Effects of group size on agonistic interactions in dairy cows: a descriptive study.

Group-housed cattle may engage in agonistic interactions over resources such as feed, which can negatively affect aspects of welfare. Little is known about how contextual factors such as group size influence agonistic behaviour. We explored the frequency of agonistic interactions at the feeder when cattle were housed in different-sized groups. We also explored the consistency of the directionality of agonistic interactions in dyads and of the number of agonistic interactions initiated by individuals across the group sizes. Four replicates of 50 cows each were assessed in two group-size phases. In Phase 1, cows were kept in one group of 50. In Phase 2, these same cows were divided into five groups of 10, maintaining stocking density (i.e., ratio of animals to lying stalls and feed bunk spaces). We measured agonistic replacements (i.e., interactions that result in one cow leaving the feed bin and another taking her place) at an electronic feeder using a validated algorithm. We used these data from Phase 1 to calculate individual Elo-ratings (a type of dominance score). Cows were then categorised into five dominance categories based upon these ratings. To ensure a consistent Elo-rating distribution between phases, two cows from each dominance category were randomly assigned to each small group of 10 cows. The mean ± SE number of replacements per cow was similar regardless of whether the cows were housed in groups of 50 (34.1 ± 2.4) or 10 (31.1 ± 4.5), although the groups of 10 were more variable. Further, 81.6 ± 7.7% (mean ± SD) of dyads had the same directionality across group sizes (i.e., the same individual won the majority of interactions in the dyad) and individuals were moderately consistent in the number of replacements they initiated (intraclass correlation coefficient = 0.62 ± 0.11; mean ± SD). These results indicate that the relationship between group size and agonistic behaviour is complex; we discuss these challenges and suggest new avenues for further research.

Genome-wide association study identifies quantitative trait loci affecting cattle temperament.

Cattle temperament is an interesting trait due to its correlation with production efficiency, labor safety, and animal welfare. To date, however, its genetic basis is not clearly understood. Here, we performed a genome-wide association study for a series of temperament traits in cattle, assessed with via open field and novel object tests, using autosomal single nucleotide polymorphisms (SNPs) derived from the whole-genome sequence. We identified 37 and 29 genome-wide significant loci in the open field and novel object tests, respectively. Gene set analysis revealed the most significant pathway was the neuroactive ligand-receptor interaction pathway, which may be essential for emotional control in cattle. Analysis of the expression levels of 18 tissue-specific genes based on transcriptomic data showed enrichment in the brain, with some candidate genes involved in psychiatric and neurodegenerative diseases in humans. Based on principal component analysis, the first principal component explained the largest variance in the open field and novel object test data, and the most significant loci were assigned to SORCS3 and SESTD1, respectively. Our findings should help facilitate cattle breeding for sound temperament by pyramiding favorable alleles to further improve cattle production.

Classification of environmental factors potentially motivating for dairy cows to access shade.

The aim of this Research Communication was to apply the data mining technique to classify which environmental factors have the potential to motivate dairy cows to access natural shade. We defined two different areas at the silvopastoral system: shaded and sunny. Environmental factors and the frequency that dairy cows used each area were measured during four days, for 8 h each day. The shaded areas were the most used by dairy cows and presented the lowest mean values of all environmental factors. Solar radiation was the environmental factor with most potential to classify the dairy cow's decision to access shaded areas. Data mining is a machine learning technique with great potential to characterize the influence of the thermal environment in the cows' decision at the pasture.

Investigating cow-calf contact in a cow-driven system: performance of cow and calf.

In this research communication we describe the performance of dairy cow-calf pairs in two cow-driven CCC-systems differing in cows' access to the calves through computer-controlled access gates (smart gates, SG). We investigated cows' machine milk yield in the automatic milking system (AMS), calf growth, and intake of supplemental milk and concentrate. Two groups each with four cow-calf pairs were housed in a system with a cow area, a calf creep and a meeting area. SG's controlled cow traffic between the meeting area and the cow area where cows could obtain feed, cubicles and the AMS. Calves had ad libitum access to supplemental milk and concentrate. During the suckling phase of 31 d, cow access to the meeting area was free 24 h/d (group 1) or restricted (group 2) based on milking permission. Following the suckling phase, cow access was gradually decreased over 9 d (separation phase). During the suckling phase, cows' machine milk yield (mean ± sd) in the AMS was 11.4 ± 6.38 kg/d. In the separation phase, the yield increased to 25.0 ± 10.37 kg/d. Calf average daily gain (ADG) was high during the suckling phase: 1.2 ± 0.74 kg. During the separation phase, ADG decreased to 0.4 ± 0.72 kg which may be related to a low intake of supplemental milk. Calves' concentrate intake increased with age, and all calves consumed >1 kg/d after separation. We conclude that cows nurse the calf in a cow-directed CCC system well resulting in high ADG, and AMS milk yields were, at least, partially maintained during the suckling phase. Although the AMS yields increased in response to separation, calf ADG was decreased. A low sample size limits interpretation beyond description but provides a basis for hypotheses regarding future research into CCC-systems.

Investigating cow-calf contact in cow-driven systems: behaviour of the dairy cow and calf.

Research is needed on how technology can facilitate cow-calf contact (CCC). This research communication describes the behaviour of dairy cow-calf pairs in two cow-driven CCC-systems differing in cows' access to the calves through computer-controlled access gates (smart gates, SG). Specifically, cow traffic through SG when visiting their calves, allogrooming, suckling and cross-suckling, cows' eating and resting behaviour and finally vocal response to separation were assessed. After 3 d in an individual calving pen, pairs (n = 8) were moved to the CCC compartment with a cow area, a calf creep and a meeting area. During the next 31 d calves could suckle the cows whenever they visited the meeting area (suckling phase). Cows had free (group 1, n = 4 pairs) or restricted access to the calves based on previous activity in the automatic milking system (group 2, n = 4 pairs). SG's controlled cow traffic between the meeting area and the cow area, in which the cows could access resources such as feed, cubicles, and the automatic milking system. Following the suckling phase cow access into the meeting area was gradually decreased over 9 d (separation phase). During the suckling phase, cows paid frequent and short visits to their calves. Pairs spent in total approximately one h/d suckling and allogrooming. However, the duration and frequencies of these events varied among pairs and groups, as did the vocal response to separation. Restricted access - cows performed more (unrewarded) attempts to visit the calves who cross-suckled more. Collectively, free access to the calves may have been more intuitive and welfare friendly. Although a low sample size limits interpretation beyond description and enabling hypothesis formulation for future research, the results indicate that the cow is motivated to visit her calf, albeit through a SG, thus facilitating particular behaviours for which cow-calf pairs are highly motivated.

Effect of grouping on behaviour of dairy heifers and cows in the transition period.

Regrouping dairy cows is a common feature of dairy farm management. Cows are grouped based on lactation stage, age, milk yield and other factors. Regrouping cows during the dry period (from far-off area to close up area and from close up area to the main herd) brings new challenges. This is especially true for heifers who, after being confirmed gravid, may be grouped into a new pen with dried off cows. The aims of this study were to determine how grouping affects activity, nearest neighbour relationships and aggression, and how heifers' acclimatization to a new group differs from cows. Therefore, the hypotheses were that regrouping cows has less of an effect on older cows compared to heifers, and cows' individuality affects acclimatization to a new group. Aggression data were recorded using a video camera that was directed at the feed bunk, and activity was recorded with activity monitors that were attached around the right hind leg. Synchrony and distance to nearest neighbour were recorded, as was the cows' location on the first 3 d from the day they returned to the main herd. Motion index, mean number of steps and number of lying bouts were significantly higher after calving compared to the week before calving and the difference was higher amongst heifers compared to cows (P < 0.001). Both cows and heifers lay down more in the strawyard compared to cubicle housing (P < 0.01) and cows were more aggressive than heifers in both housing systems (P < 0.001 and P < 0.05, respectively). As hypothesized, heifers were more affected by regrouping and cows with more experience settled quicker to their new environment.

Anticipatory behaviour as an indicator of the welfare of dairy calves in different housing environments.

Anticipatory behaviour occurs in the period before a reward or other positive event is presented and has been interpreted as an indicator of the welfare and emotional state of animals. The use of this indicator has received limited attention in dairy calves. Therefore, we investigated how anticipatory behaviour is affected by housing environment and reward quality, and if anticipatory behaviour changes when reward quality changes unexpectedly. Sixteen pairs of calves were assigned to treatments in a 2 x 2 factorial design (two housing environment and two reward quality combinations). Housing was either basic (2 m2/calf, river stone surface) or enriched (5 m2/calf, woodchip, and enrichment items), and the reward was access to either an additional basic or enriched pen. Calves were conditioned to anticipate reward pen access; anticipatory behaviour toward receiving the reward pen was measured. Signaling reward access increased the frequency of transitions between behaviours and duration of touching and looking at the signal and exit door. Basic-housed calves showed more anticipatory behaviour (increased frequency of transitions between behaviours) and decreased latency to access the reward compared to enriched-housed calves, but the reward pen quality had no effect on anticipatory behaviour. When the reward pen quality changed from enriched to basic unexpectedly, resulting in sudden reward loss, basic-housed calves decreased, while enriched-housed calves increased, anticipatory behaviour. However, there was no change in anticipatory behaviour during reward gain (change from basic to enriched reward pen). Our findings align with previous work showing that animals in basic housing show more anticipation for a reward, and demonstrate suppressed behavioural response when experiencing reward loss, suggesting greater sensitivity to reward. Sensitivity to reward has associations with mood state; thus, calves in basic environments may experience a more negative emotional state, and thus reduced welfare, compared to calves in enriched environments.

Negative play contagion in calves.

Play is a strong outwardly directed, emotional behaviour and can contagiously spread between individuals. It has been suggested that high-playing animals could 'seed' play in others, spreading positive affective states. Despite the current interest in play contagion there has been no previous attempt to measure the strength of the play contagion effect. The calf (Bos taurus) is ideal for testing the strength of play contagion as play in calves is strongly related to energy intake from milk. We manipulated play in calves through their milk allowances and housed the calves in uniform groups all on the same milk allowance (high = UHigh or low = ULow) or in mixed groups with calves in the same group receiving either a high (= MHigh) or low (= MLow) milk allowance. We measured locomotor play using accelerometers on two consecutive days when calves were four and eight weeks old, in order to study play contagion over a protracted developmental window. We anticipated that differences in the level of play contagion between treatment groups would result in difference in the play levels observed in the MLow and ULow individuals. Contrary to our expectations we found that spontaneous play was suppressed in the high-milk calves housed in mixed groups (MHigh), in comparison to calves housed with group mates all receiving high-milk (UHigh). These results are the first to quantify a negative play contagion effect, particularly in a situation of long-term contact, and may suggest that negative contagion has a stronger effect on play behaviour than positive contagion.

Calves' management conditions affect sperm count in adult bulls.

BACKGROUND: Early maternal separation may have long-lasting physiological effects on different organ systems. Although long-lasting effects of early maternal separation are mostly studied in connection with the development and function of the central nervous system hypothalamic-pituitary-adrenal axis, animal health, behaviour and productivity, there is a lack of information about its impacts on the reproductive system. In the dairy industry, calves are often separated from mothers 1 or 2 days after birth and are not nursed. In the present retrospective study based on data from an artificial insemination (AI) centre, we compared semen parameters and fertility in bulls that were separated from their mothers one day after birth with the semen parameters of bulls that remained with their mothers and were nursed for approximately 2 months. Semen parameters were followed in 3 consecutive years in 52 maternally separated and 22 nursed bulls. RESULTS: Ejaculate volume and total sperm count in ejaculate were significantly higher in nursed bulls in comparison to maternally separated bulls at the age 25-36 and 37-48 months, but interestingly, not at the age 12-24 months, during the first year in the AI centre. Non-return rates did not differ between separated and nursed bulls. CONCLUSION: The results suggest that early maternal separation causes long-lasting effects on the functioning of the male reproductive system, evident by reduced production of semen in adult bulls. The data suggest that with a standard of 20 million sperms per straw of frozen semen, 27-78 fewer straws can be obtained from one ejaculate of maternally separated bulls in comparison to the nursed bulls.

Pessimistic dairy calves are more vulnerable to pain-induced anhedonia.

Pain induces deficits in appreciation of rewards (i.e. anhedonia) and variation in response to pain may be partly explained by individual differences in general expectations (i.e. optimism). Dairy calves are routinely subjected to painful procedures such as hot-iron disbudding. We tested if female Holstein calves (n = 17) display signs of anhedonia (as evidenced by reduced consumption of a sweet solution) after hot-iron disbudding (performed under general and local anesthesia), and whether individual differences in optimism explain the variation in this response. Individual variation in optimism was measured using responses to two judgment bias tests (performed when calves were 25 d old), and anhedonia was measured by comparing consumption of a sweet solution before and after hot-iron disbudding. We found that intake of the sweet solution declined (by mean ± SD: 48.4 ± 44.3%) on the day after disbudding, and that more pessimistic calves were more affected. Sweet solution consumption did not return to baseline for the duration of the study (i.e. 5 days). Calves reduced their intake of a sweet solution after hot-iron disbudding, consistent with pain-induced anhedonia, and more pessimistic calves showed stronger evidence of anhedonia, suggesting that they were more affected by the procedure. However, our results cannot rule out the possibility that calf responses were driven by anorexia.

Short- and long-term effects of rearing dairy calves with contact to their mother on their reactions towards humans.

In this Research Communication we address the hypotheses that reduced contact with humans during the first week of life would impair the relationship of dairy calves reared in dam-calf-contact systems to humans in comparison with artificially reared animals, but that this difference would vanish over time. Artificially reared calves (Artificial) that had been separated from their mother within 12 h after birth were bottle-fed with colostrum for 5 d and thereafter sucked milk from an automatic milk feeder. Animals reared with dam-calf contact (Dam-contact) were kept in the calving pen with their dam for 5 d, and then had permanent access to the cow barn and thus to their dam. Calves were weaned at an age of 12 weeks and kept in young stock groups mixed of both treatments until integration into the cow herd. We tested the animals' relationship with humans by assessing the animals' responses towards an unfamiliar person in an avoidance distance (AD) test in the home environment at 4 weeks of age, at 15 months and at 33 months. In calves, we additionally measured AD in a novel arena after a stationary person test. Artificial animals had lower AD, i.e. showed lower level of fear, than Dam-contact calves. However, the AD in Dam-contact calves decreased with increasing number of days they experienced assistance for suckling. Further, there was no significant difference in later ages. In conclusion, gentle human contact in combination with feeding during the first 5 d of life improved calves' relationship to humans leading to differences between the two treatments as well as within the Dam-contact calves. Potential effects under different conditions regarding quantity and quality of human-animal interactions need further research.

Play and social behaviour of calves with or without access to their dam and other cows.

The aim of the study reported in this Research Communication was to compare play behaviour and social interactions of dairy calves either separated from their mother and reared in a calf group (Artificial) or with access to their mother and the cow herd (cow-calf contact: Contact). Contact calves had access to a calf area and also to the cow barn where they could suckle their dam. Artificial calves were fed whole milk up to 16 kg per day via an automatic milk feeder and were only kept in the calf area. We observed the animals on 3 d during the first three months of life. Contact calves showed solitary play, consisting predominantly of locomotor play, for longer than Artificial calves and mainly in the cow barn. This indicates higher welfare in Contact calves. In addition, Artificial calves hardly experienced any agonistic interaction, while Contact calves both initiated and received agonistic interactions, which might contribute to the development of higher social competence.

Physical development, ease of integration into the dairy herd and performance of primiparous dairy cows reared with full whole-day, half-day or no mother-contact as calves.

We investigated whether different rearing conditions affected the physical development, ease of integration into the dairy herd and performance of primiparous dairy cows and the results are reported in this Research Communication. The three rearing conditions investigated were whole-day cow-calf contact for 9 weeks (WDC), half-day contact for nine weeks (HDC) and no mother-contact (NC) with nipple-bucket-feeding (max. 2 × 3 l/d) and group-housing from the 8th day onward. After permanent separation from the dams (WDC and HDC), all calves had been nipple-bucket-fed and gradually weaned from week 10 to 13 of life and kept together as calves and heifers. Measures of physical development were trunk girth, height at withers and body weight. Lying behavior during the first 48 h after introduction to the dairy herd after first calving was used as an indicator of ease of integration. Performance measures were age at calving, lactation duration, milk yield and culling rates during the first lactation. No differences between WDC and HDC could be detected. Moreover, no treatment-effects on physical development or performance could be found. All treatments showed reduced lying for the first 24 h after introduction to the dairy herd. Afterward NC-heifers lay less than WDC, with HDC-heifers ranging in between. We conclude that under the conditions investigated higher weights two weeks after weaning in WDC- and HDC-calves did not carry through to the first lactation and did not lead to earlier maturity and higher performance, but that integration into the herd may be alleviated when calves have early experience of the herd and associated conditions.

The cow-calf relationship: from maternal responsiveness to the maternal bond and the possibilities for fostering.

The relationship between the cow and calf develops over time after birth. The behavioural mechanisms underlying its development are important and comparisons with other species may increase our understanding. In nature the cow will separate herself from the herd to give birth and then the cow-calf relationship will develop with the ability to recognise each other. While twinning levels are low in cows, they do rear their twin calves. If the calf is lost at or after birth the cow can be responsive towards other calves and in specific circumstances the cow can develop a maternal bond with an alien calf, i.e. foster. In this Research Reflection a distinction is made between the development of, on the one hand, maternal responsiveness (the tendency of the cow to care for a calf which occurs before birth) and, on the other hand, the development of the maternal-filial bond or relationship which is reciprocal, occurs after birth and is characterised by the ability to discriminate the mother's own calf from alien calves. These processes can overlap and the relationship between cow and calf in this 'hider' species is more plastic than in some other mammals. For example, a cow might form an attachment with an alien calf before she gives birth. After the cow has given birth the loss of her own calf may result in the state of maternal responsiveness being maintained, such that developing a maternal bond with one or several appropriate alien calves is possible. Viable fostering techniques are possible. If a maternal relationship to the mother's own calf has developed then fostering will be more difficult. If the cow's relationship with her own calf is not exclusive, and she is in a state of maternal responsiveness then fostering of calves of an appropriate age and status can be achieved.

Heat stress in dairy calves from birth to weaning.

This Research Reflection collects current knowledge on the effects of heat stress in dairy calves. Chapters cover the concept of foetal programming, animal-based and environmental indicators of heat stress in the postnatal period, and methods of heat stress abatement. Conclusions for further research about economic efficiency, research methodology and an integrated approach of pre- and postnatal heat stress are also proposed.

Methodology for experimental and observational animal studies in cow-calf contact systems.

In this Research Reflection we describe a common standpoint on suitable methodology for controlled and observational studies in cow-calf contact systems in dairy production. Different methods to assess behaviour, health and production in cow-calf contact systems are outlined. Knowledge and experience from researchers working in this field supplement scientific literature whenever relevant. Specific methods including study design, early behaviour of cow and calf, social behaviour relevant to cow-calf contact systems, human-animal relationships and aspects related to management (milking, weaning and separation, health) are reviewed, and recommendations formed. We expect that this paper can contribute to a better understanding of the complexity of cow-calf contact systems and help to advance research in this area of dairy production.

Using imputed whole-genome sequence variants to uncover candidate mutations and genes affecting milking speed and temperament in Holstein cattle.

Milking speed (MS) and temperament (MT) are 2 workability traits of great importance in dairy cattle production and breeding. This is mainly due to an increased intensification of the worldwide production systems and greater adoption of precision technologies with less human-cattle interaction. Both MS and MT are heritable traits and thus, genomic selection is a promising tool to expedite their genetic progress. However, the genetic architecture and biological mechanisms underlying the phenotypic expression of these traits remain underexplored. In this study, we investigated the association of >5.7 million imputed whole-genome sequence variants with MT and MS in 4,381 and 4,219 North American Holstein cattle, respectively. The statistical analyses were performed using a mixed linear model fitting a polygenic effect. We detected 40 and 35 significant SNPs independently associated with MT and MS, respectively, which were distributed across 26 chromosomes. Eight candidate genes (GRIN3A, KCNJ3, BOSTAUV1R417, BOSTAUV1R419, MAP2K5, KCTD3, GAP43, and LSAMP) were suggested to play an important role in MT as they are involved in biologically relevant pathways, such as glutamatergic synapse, vomeronasal receptor and oxytocin signaling. Within their coding and upstream sequences, we used an independent data set to further detect or validate significantly differentiated SNP between cattle breeds with known differences in MT. There were fewer candidate genes potentially implicated in MS, but immunity-related genes (e.g., BOLA-NC1 and LOC512672), also identified in other populations, were validated in this study. The significant SNP and novel candidate genes identified contribute to a better understanding of the biological mechanisms underlying both traits in dairy cattle. This information will also be useful for the optimization of prediction of genomic breeding values by giving greater weights to SNP located in the genomic regions identified.

Novel genes involved in the genetic architecture of temperament in Brahman cattle.

Cattle temperament is a complex and economically relevant trait. The objective of this study was to identify genomic regions and genes associated with cattle temperament. From a Brahman cattle population of 1,370 animals evaluated for temperament traits (Exit velocity-EV, Pen Score-PS, Temperament Score-TS), two groups of temperament-contrasting animals were identified based on their EV-average values ±1/2 standard deviation (SD). To be considered in the calm group, the EV of females ranged between 0.16-1.82 m/s (n = 50) and the EV of males ranged between 0.4-1.56 m/s (n = 48). Females were classified as temperamental if their EV ranged between 3.13-7.66 m/s (n = 46) and males were classified as temperamental if their EV ranged between 3.05-10.83 m/s (n = 45). Selected animals were genotyped using a total of 139,376 SNPs (GGP-HD-150K), evaluated for their association with EV. The Genome-Wide Association analysis (GWAS) identified fourteen SNPs: rs135340276, rs134895560, rs110190635, rs42949831, rs135982573, rs109393235, rs109531929, rs135087545, rs41839733, rs42486577, rs136661522, rs110882543, rs110864071, rs109722627, (P<8.1E-05), nine of them were located on intergenic regions, harboring seventeen genes, of which only ACER3, VRK2, FANCL and SLCO3A1 were considered candidate associated with bovine temperament due to their reported biological functions. Five SNPs were located at introns of the NRXN3, EXOC4, CACNG4 and SLC9A4 genes. The indicated candidate genes are implicated in a wide range of behavioural phenotypes and complex cognitive functions. The association of the fourteen SNPs on bovine temperament traits (EV, PS and TS) was evaluated; all these SNPs were significant for EV; only some were associated with PS and TS. Fourteen SNPs were associated with EV which allowed the identification of twenty-one candidate genes for Brahman temperament. From a functional point of view, the five intronic SNPs identified in this study, are candidates to address control of bovine temperament, further investigation will probe their role in expression of this trait.

Short communication: Motivation to walk affects gait attributes.

Lameness is a major welfare problem in the dairy industry. Environmental factors, such as flooring surface, as well as cow-level factors, such as udder fill, can influence gait. The aim of the current study was to test whether motivation to walk affects gait attributes and whether this effect differs between lame and sound cows. We trained cows to walk down an alley for a food reward and assessed walking speed, stride length, head bob, and back arch of cows previously identified as either lame (n = 7) or sound (n = 10). Cows were assessed when they walked toward a food reward and toward no reward. Cows walked faster and had longer stride length and less variation in head bob when approaching the reward; these effects were similar in both sound and lame cows. We concluded that motivation to walk affects several gait attributes of dairy cows.

Genetic control of temperament traits across species: association of autism spectrum disorder risk genes with cattle temperament.

BACKGROUND: Temperament traits are of high importance across species. In humans, temperament or personality traits correlate with psychological traits and psychiatric disorders. In cattle, they impact animal welfare, product quality and human safety, and are therefore of direct commercial importance. We hypothesized that genetic factors that contribute to variation in temperament among individuals within a species will be shared between humans and cattle. Using imputed whole-genome sequence data from 9223 beef cattle from three cohorts, a series of genome-wide association studies was undertaken on cattle flight time, a temperament phenotype measured as the time taken for an animal to cover a short-fixed distance after release from an enclosure. We also investigated the association of cattle temperament with polymorphisms in bovine orthologs of risk genes for neuroticism, schizophrenia, autism spectrum disorders (ASD), and developmental delay disorders in humans. RESULTS: Variants with the strongest associations were located in the bovine orthologous region that is involved in several behavioural and cognitive disorders in humans. These variants were also partially validated in independent cattle cohorts. Genes in these regions (BARHL2, NDN, SNRPN, MAGEL2, ABCA12, KIFAP3, TOPAZ1, FZD3, UBE3A, and GABRA5) were enriched for the GO term neuron migration and were differentially expressed in brain and pituitary tissues in humans. Moreover, variants within 100 kb of ASD susceptibility genes were associated with cattle temperament and explained 6.5% of the total additive genetic variance in the largest cattle cohort. The ASD genes with the most significant associations were GABRB3 and CUL3. Using the same 100 kb window, a weak association was found with polymorphisms in schizophrenia risk genes and no association with polymorphisms in neuroticism and developmental delay disorders risk genes. CONCLUSIONS: Our analysis showed that genes identified in a meta-analysis of cattle temperament contribute to neuron development functions and are differentially expressed in human brain tissues. Furthermore, some ASD susceptibility genes are associated with cattle temperament. These findings provide evidence that genetic control of temperament might be shared between humans and cattle and highlight the potential for future analyses to leverage results between species.