Search

A genomic study was conducted to identify the effects of urbanization and environmental contaminants with heavy metals on selection footprints in dairy cattle populations reared in the megacity of Bengaluru, South India. Dairy cattle reared along the rural–urban interface of Bengaluru with/without access to roughage from public lakeshores were selected. The genotyped animals were subjected to the cross-population–extended haplotype homozygosity (XP-EHH) methodology to infer selection sweeps caused by urbanization (rural, mixed, and urban) and environmental contamination with cadmium and lead. We postulated that social-ecological challenges contribute to mechanisms of natural selection. A number of selection sweeps were identified when comparing the genomes of cattle located in rural, mixed, or urban regions. The largest effects were identified on BTA21, displaying pronounced peaks for selection sweeps for all three urbanization levels (urban_vs_rural, urban_vs_mixed and rural_vs_mixed). Selection sweeps are located in chromosomal segments in close proximity to the genes lrand rab interactor 3 (RIN3), solute carrier family 24 member 4 (SLC24A4), tetraspanin 3 (TSPAN3), and proline-serine-threonine phosphatase interacting protein 1 (PSTPIP1). Functional enrichment analyses of the selection sweeps for all three comparisons revealed a number of gene ontology (GO) and KEGG terms, which were associated with reproduction, metabolism, and cell signaling-related functional mechanisms. Likewise, a number of the chromosomal segments under selection were observed when creating cattle groups according to cadmium and lead contaminations. Stronger and more intense positive selection sweeps were observed for the cadmium contaminated group, i.e., signals of selection on BTA 16 and BTA19 in close proximity to genes regulating the somatotropic axis (growth factor receptor bound protein 2 (GRB2) and cell ion exchange (chloride voltage-gated channel 6 (CLCN6)). A few novel, so far uncharacterized genes, mostly with effects on immune physiology, were identified. The lead contaminated group revealed sweeps which were annotated with genes involved in carcass traits (TNNC2, SLC12A5, and GABRA4), milk yield (HTR1D, SLCO3A1, TEK, and OPCML), reproduction (GABRA4), hypoxia/stress response (OPRD1 and KDR), cell adhesion (PCDHGC3), inflammatory response (ADORA2A), and immune defense mechanism (ALCAM). Thus, the findings from this study provide a deeper insight into the genomic regions under selection under the effects of urbanization and environmental contamination. [ABSTRACT FROM AUTHOR]

This document explores the impact of heat stress on ruminant livestock production and offers strategies to mitigate its effects. Heat stress can lead to reduced feed intake, lower meat and milk production, and damage to the intestines. Short-term solutions include providing shade, water, adjusting feeding patterns, and improving ventilation. Long-term strategies involve genetic selection for heat tolerance and climate adaptation. The document emphasizes the need for a multidisciplinary approach and the integration of new technologies to address the impact of climate change on livestock. [Extracted from the article]

A 45-day study was conducted where the primary objective was to evaluate the effect of simultaneously imposed multiple stressors (thermal, nutritional, and walking) on the adaptive capability of Malpura rams based on changes in ingestive behavior, physiological, blood biochemical, and endocrine responses. Twenty adult Malpura rams (average body weight 44.9 kg) were used in the study. The rams were divided into 2 groups, CON (n = 10; control) and multiple stressors (MS; n = 10; multiple stressors). All of the rams were stall fed with a diet consisting of 70% roughage and 30% concentrate. The CON rams were maintained in a shed under ambient conditions with ad libitum feeding without walking, whereas MS rams were subjected to multiple stressors (thermal, nutritional, and walking). The feed intake ( P < 0.01) was lower and water intake ( P < 0.01) was higher in MS compared to CON rams. Among the physiological measurements, respiration rate afternoon ( P < 0.01), pulse rate morning ( P < 0.01), rectal temperature afternoon ( P < 0.01), skin temperature afternoon ( P < 0.05), and both morning and afternoon scrotum temperature ( P < 0.01) increased significantly in MS rams. Both hemoglobin ( P < 0.05), packed cell volume ( P < 0.01), increased and plasma glucose ( P < 0.01) reduced significantly ( P < 0.01) in MS as compared to CON rams. Among the endocrine parameters, the plasma cortisol increased and plasma thyroxin reduced significantly ( P < 0.05) in MS rams. The study indicates that Malpura rams have the capability to adjust their physio-biochemical and endocrine responses to cope with multiple stressors in a hot semi-arid environment. Furthermore, the study also indicated that respiration rate, rectal temperature, scrotal temperature, hemoglobin, packed cell volume, and cortisol may act as ideal biological markers for quantifying the impact of multiple stressors in Malpura rams. [ABSTRACT FROM AUTHOR]

The study was conducted to ascertain the effects of nutritional restrictions on growth, physiological adaptability and reproduction in sheep. The experiment was conducted for a period of 35 days covering two estrus cycles in 40 adult Malpura ewes. The animals were randomly divided into four groups of 10 animals each (100%; 80%; 70%; 60% of ad libitum). The ewes were fed a ration consisting of 70% roughage and 30% concentrate. At weekly intervals, physiological responses were recorded and blood samples were also collected. Nutritional restriction of different magnitude (80%; 70%; 60% of ad libitum) altered the growth, physiological adaptability and estrus responses to different extents in Malpura ewes. But the impact was most severe in 60% of ad libitum group. Nutritional restriction to the level of 60% of ad libitum feeding significantly decreased body weight, body condition score, plasma insulin-like growth factor, pulse rate in the morning, respiration rate and pulse rate in the afternoon, plasma glucose, total protein, albumin, total cholesterol, plasma tri-iodo-thyronine and thyroxine, plasma Cortisol, plasma estradiol, estrus % and estrus duration, while it significantly increased plasma concentration of growth hormone, hemoglobin, plasma concentration of progesterone and estrus cycle length. The study clearly establishes the effect of different levels of nutrition and its impact on the biological functions necessary to adapt to semi-arid environment. Although, 80%, 70% and 60% groups showed signs of nutritional stress, the effects were more pronounced in 60% ewes. Furthermore, this study clearly establishes the role of various hormones required to adapt to different levels of nutritional stress in Malpura ewes. [ABSTRACT FROM AUTHOR]