Chris Major N'Cho


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N'Cho

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Chris Major

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0000-0002-6638-6730

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2024 - 20255
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Publications 1 - 5 of 5
  • Abiotic stressors in poultry production: A comprehensive review
    Item type: Review Article
    N'Cho, Chris Major; Berdos, Janine I.; Gupta, Vaishali; et al. (2025)
    Journal of Animal Physiology and Animal Nutrition
    In modern animal husbandry, stress can be viewed as an automatic response triggered by exposure to adverse environmental conditions. This response can range from mild discomfort to severe consequences, including mortality. The poultry industry, which significantly contributes to human nutrition, is not exempt from this issue. Although genetic selection has been employed for several decades to enhance production output, it has also resulted in poor stress resilience. Stress is manifested through a series of physiological reactions, such as the identification of the stressful stimulus, activation of the sympathetic nervous system and the adrenal medulla, and subsequent hormonal cascades. While brief periods of stress can be tolerated, prolonged exposure can have more severe consequences. For instance, extreme fluctuations in environmental temperature can lead to the accumulation of reactive oxygen species, impairment of reproductive performance, and reduced immunity. In addition, excessive noise in poultry slaughterhouses has been linked to altered bird behaviour and decreased production efficiency. Mechanical vibrations have also been shown to negatively impact the meat quality of broilers during transport as well as the egg quality and hatchability in hatcheries. Lastly, egg production is heavily influenced by light intensity and regimens, and inadequate light management can result in deficiencies, including visual anomalies, skeletal deformities, and circulatory problems. Although there is a growing body of evidence demonstrating the impact of environmental stressors on poultry physiology, there is a disproportionate representation of stressors in research. Recent studies have been focused on chronic heat stress, reflecting the current interest of the scientific community in climate change. Therefore, this review aims to highlight the major abiotic stressors in poultry production and elucidate their underlying mechanisms, addressing the need for a more comprehensive understanding of stress in diverse environmental contexts.
  • Meta-analysis to determine the effects of supplementation of niacin during the transition or lactating period on performance in dairy cows
    Item type: Journal Article
    Arshad, Usman; Bagaria, Sahil; N'Cho, Chris Major; et al. (2025)
    Journal of Dairy Science
    Niacin, a key component of pyridine nucleotides, plays a vital role in over 200 metabolic reactions, including carbohydrate, lipid, and AA metabolism. This meta-analysis aimed to evaluate the effects of niacin supplementation on lactational performance in dairy cows. We hypothesized that niacin supplementation during the transition or lactating periods would enhance the productive performance of dairy cows. A systematic review identified 41 experiments, comprising 128 treatment means and 1,992 cows, which were included in the meta-analysis. Each experiment featured a non-supplemented control (CON) group and a supplemented group, with niacin provided as either rumen-unprotected niacin (RUPN) or rumen-protected niacin (RPN). Supplementation was initiated during either the transition or lactating period, resulting in the categorization of data into 4 distinct cohorts: cows supplemented with RUPN or RPN during either the transition or lactating periods. Cows supplemented with RUPN during the transition (CON; n = 13 treatment means vs. RUPN; n = 14 treatment means) and lactating periods (CON; n = 33 treatment means vs. RUPN; n = 40 treatment means) had average niacin intakes (mean ± SD) of 13.9 ± 10.8 g/d and 9.1 ± 3.5 g/d, respectively. Cows supplemented with RPN during the transition (CON; n = 4 treatment means vs. RPN; n = 4 treatment means) and lactating periods (CON; n = 8 treatment means vs. RPN; n = 12 treatment means) had niacin intakes of 11.7 ± 7.3 g/d and 4.6 ± 2.0 g/d, respectively. Mixed models were used to investigate the linear and quadratic effects of RUPN or RPN. Meta-analytical statistics in STATA estimated the weighted mean difference (WMD) of milk yield for treatment comparisons (CON vs. RUPN and CON vs. RPN). All models included the random effect of experiment and weighting by the inverse of the SEM squared. Supplementation of niacin, whether from RUPN or RPN, during the transition period did not improve performance in dairy cows. However, RUPN supplementation during the regular lactating period led to linear increases in DMI, yields of milk, ECM, protein and lactose, and increments of 0.50, 0.90, 0.70, 0.04, and 0.05 kg/d, respectively, were observed when cows were supplemented with 9.1 g/d RUPN. In 38 treatment comparisons from 20 experiments evaluating RUPN supplementation during the lactating period, the mean response indicated that RUPN cows produced 0.83 kg/d more milk than CON cows (WMD = 0.83; 95% CI = 0.35 to 1.31), with moderate (I2 = 61.7%) heterogeneity observed. Similarly, RPN supplementation during the lactating period led to linear increases in DMI, yields of milk, ECM, fat and lactose, with respective increases of 0.60, 1.10, 0.70, 0.06, and 0.05 kg/d when cows were supplemented with 4.7 g/d niacin. Across 12 treatment comparisons from 8 experiments, RPN-supplemented cows produced 0.96 kg/d more milk than CON cows (WMD = 0.96; 95% CI = 0.62 to 1.31), with no heterogeneity observed. Overall, feeding 9.1 g/d of niacin from RUPN or 4.7 g/d of niacin from RPN during the lactating period improved milk production without improving feed efficiency in dairy cows.
  • Heat stress and the chicken gastrointestinal microbiota: a systematic review
    Item type: Review Article
    N'Cho, Chris Major (2025)
    Journal of Animal Science and Biotechnology
    Heat stress (HS) has become a significant challenge for poultry farming due to an increase in global temperatures. Existing literature suggests that the health effects of HS in chickens are related to its impact on the gastrointestinal tract. While there is evidence of the detrimental consequences of HS on the gut structure, little is known about the effects of HS on the microbial population inhabiting this organ. Fortunately, recent advancements in "omics" technologies have made investigating the interaction between HS and the gut microbiota possible. Therefore, a systematic review was conducted to assess the effects of HS on chicken gut microbiota. In July 2024, a comprehensive literature search was performed across scientific repositories, including Scopus, PubMed, Science Direct, and Google Scholar. Eighteen studies met the eligibility criteria for inclusion and a qualitative synthesis of their results was conducted according to the PRISMA guidelines. Current evidence indicates that HS poses a significant challenge to the gastrointestinal system of chickens, resulting in a range of physiological reactions. These changes trigger fierce competition among beneficial microbial species for limited nutrients, promote microbial shifts from obligate to facultative anaerobes, and increase the abundance of microbial species with high resistance to elevated environmental temperatures. Furthermore, the proliferation of pathogens is exacerbated. Ultimately, gut microbiota profiling highlights changes in microbial diversity, alterations in the composition of microbial populations, disruptions in specific microbial functional pathways (tricarboxylic acid cycle, amino acid metabolism, antioxidant biosynthesis, and fatty acid degradation), and the breakdown of complex networks that govern microbial interactions. Understanding the complex relationship between HS and microbial shifts within the chicken gut can provide valuable insights for the development of sustainable mitigation strategies. Further research is needed to expand the current knowledge and employ more advanced literature synthesis techniques such as meta-analyses.
  • Predicting sleep events in dairy cows by machine learning using respiratory rate and 3D accelerometer data
    Item type: Conference Paper
    N'Cho, Chris Major; Zhao, Xinjie; Räisänen, Susanna; et al. (2024)
    Precision Livestock Farming 2024: Papers presented at the 11th European Conference on Precision Livestock Farming
    The conventional method for studying sleep in dairy cows relies heavily on polysomnography (PSG), which is considered the gold standard. However, PSG is not practical for farming conditions, such as grazing or free stalls. Therefore, there is a need for accurate and practical sleep measurement tools for the sleep monitoring and welfare assessment of dairy cows. This study aimed to explore the potential of detecting sleep events from wearable sensor data in dairy cows using machine-learning algorithms (neural network, random forest, and support vector machine). The models were trained using data from 13 cows equipped with smart halters during a 24-hour PSG recording session. Cross-validation results showed that the random forest algorithm achieved a sensitivity value of up to 83%. All models were able to distinguish sleep-wake events with a balanced accuracy within the range of 82 to 83% on a previously unseen test set. Variable importance metrics suggested that the 3D positioning axis and pressure from jaw movements were the most discriminative features for the detection of sleep events. Further research is necessary to evaluate the models' performance for the detection of sleep stages and may require larger sample sizes and improved feature engineering.
  • Impact of dietary polyphenols from shredded, steam-exploded pine on growth performance, organ indices, meat quality, and cecal microbiota of broiler chickens
    Item type: Journal Article
    N'Cho, Chris Major; Gupta, Vaishali; Goel, Akshat; et al. (2025)
    Poultry Science
    The chicken's gastrointestinal tract is home to complex and diverse microbial communities that can be manipulated to enhance health and productivity. Although polyphenols have recently attracted the attention of researchers due to their potent antioxidant capabilities, their impact on the gut microbiota remains largely unexplored. Hence, in this study, we conducted a comprehensive analysis of the effects of dietary supplementation with polyphenol-rich extract from shredded, steam-exploded pine particles (PSPP) on growth, meat quality, and gut microbial dynamics in broiler chickens. Supplementation of PSPP was found to significantly improve birds' FCR until the third week of the trial but only marginally affected meat quality. Based on meta-taxonomic analyses of the cecal microbiotas of broilers fed increasing concentrations of PSPP, dietary PSPP modulated the composition of the cecal microbiota of the birds with a concomitant increase of Bacteroidetes and a decrease in the Firmicutes population. Similar trends were observed for the proportions of Alistipes and Faecalibacterium at the genus level. Additionally, 43 unique bacterial species were detected in the cecal microbiome of birds fed with PSPP. However, microbial diversity did not vary significantly among treatment groups. A particularly interesting finding was the specialization observed in the microbiome of birds receiving PSPP supplementation. Microbial co-occurrence network analyses revealed substantial modifications in their network structure when compared to control birds. Families like Rikenellaceae and Eubacteriaceae were notably absent, and the number of microbial interactions was drastically lower in the PSPP-fed group. Microbial taxa modeling revealed that the impact of increasing dietary PSPP levels primarily affected genus-level taxa, showing a decreasing trend. Overall, this offers compelling evidence that continuous PSPP supplementation may not only alter the composition of intestinal microbes but also have a profound effect on the interactions among different microbial species. Conversely, PSPP had minimal effects on broilers' performance and meat quality.
Publications 1 - 5 of 5