Changes in Blood Metabolites and Immune Cells in Holstein and Jersey Dairy Cows by Heat Stress

Beef cattle phenotypes are affected by the consumption of toxic fescue. Toxic fescue’s impact is dependent on heat stress and breed composition, with genetic variability for robustness to toxin exposure believed to exist within and across breeds. The study objective was to characterize the effect of fescue toxicosis across breeds for known and novel heat and fescue stress-associated phenotypes. One-hundred crossbred fall-calving Charolais- and Hereford-sired cows of parities 1–3 were allocated to graze either toxic fescue (n = 50), non-toxic fescue (n = 25), or a rotation between toxic and non-toxic fescue (n = 25) for 156 days. Phenotypes impacted by breed (genetics) included hair coat score (p < 0.0001), hair reduction/shedding rate (p < 0.05), rectal temperature (RT) (p < 0.0001), vaginal temperature (p < 0.05), serum phosphorus concentration (p < 0.02) and respiration rate (RR) (p < 0.003). Cows on toxic fescue experienced reduced hair shedding efficacy (p < 0.0001), higher vaginal temperatures (p < 0.0001), increased systolic blood pressure (p < 0.04), increased RR (p < 0.0001) and reduced average daily gain (p < 0.0001), compared to cows grazing non-toxic fescue. Calves born from cows with higher RT during the last third of gestation had higher RT at weaning (p < 0.02), indicating potential physiological effects of in utero heat stress. The study indicates that beef cows exhibit variable responses to toxic fescue within and across breeds which may impact future calf phenotypes.

Section: Blood Serum Phosphorus and Magnesium Are Impacted By Sire Breed And Toxic Fescue Exposurecontrasting

confidence: 52%

Section: Blood Serum Phosphorus and Magnesium Are Impacted By Sire Breed And Toxic Fescue Exposuresupporting

confidence: 39%

Identification of Breed Differences in Known and New Fescue Toxicosis Associated Phenotypes in Charolais-and Hereford-Sired Crossbred Beef Cows

Lucas

Koltes

Meyer

et al. 2021

“…Decreased protein synthesis is supported by a lower level of THY in period 1 than 4. Lower concentrations of TP in blood were also noted in heat-stressed dairy cows [ 47 ].…”

Section: Discussionmentioning

confidence: 99%

Effects of High Heat Load Conditions on Blood Constituent Concentrations in Dorper, Katahdin, and St. Croix Sheep from Different Regions of the USA

Tadesse

Patra

Puchała

et al. 2022

Forty-six Dorper (DOR), 46 Katahdin (KAT), and 43 St. Croix (STC) female sheep (initial body weight of 58, 59, and 46 kg, respectively, SEM = 1.75; 3.3 ± 0.18 years of age, 2.6–3.7), derived from 45 commercial farms in four regions of the USA (Midwest, Northwest, Southeast, and central Texas), were used to evaluate responses in blood constituent concentrations to increasing heat load index (HLI) conditions. There were four sequential 2 weeks periods with target HLI during day/nighttime of 70/70 (thermoneutral zone conditions), 85/70, 90/77, and 95/81 in period 1, 2, 3 and 4, respectively. A 50% concentrate pelletized diet was fed at 53.3 g dry matter/kg body weight0.75. The analysis of most constituents was for samples collected on the last day of the second week of each period at 13:00 h; samples for cortisol, thyroxine, and heat shock protein were collected in week 2 and 8. Previously, it was noted that resilience to high HLI conditions was greatest for STC, lowest for DOR, and intermediate for KAT. There were few effects of region. Other than hemoglobin concentration, there were no interactions between breed and period. Blood oxygen concentration was greatest (p < 0.05) among breeds for STC (5.07, 5.20, and 5.53 mmol/L for DOR, KAT, and STC, respectively; SEM = 0.114) and differed among periods (4.92, 5.26, 5.36, and 5.52 mmol/L for period 1, 2, 3, and 4, respectively; SEM = 0.093). There were breed differences (i.e., main effects; p < 0.05) in glucose (50.0, 52.6, and 52.1 mg/dL; SEM = 0.76), urea nitrogen (17.2, 17.3, and 19.4 mg/dL; SEM = 0.33), creatinine (0.991, 0.862, and 0.802 mg/dL; SEM = 0.0151), total protein (6.50, 6.68, and 6.95 g/l; SEM = 0.017), triglycerides (28.4, 29.1, and 23.5 mg/dL; SEM = 0.87), and cortisol (6.30, 8.79, and 6.22 ng/mL for DOR, KAT, and STC, respectively; SEM = 0.596). Differences among periods (p < 0.05) were observed for lactate (27.9, 25.3, 27.8, and 24.0 mg/dL; SEM = 0.99), creatinine (0.839, 0.913, 0.871, and 0.917 mg/dL; SEM = 0.0128), total protein (6.94, 6.66, 6.60, and 6.65 g/l; SEM = 0.094), and cholesterol (60.2, 56.5, 58.3, and 57.6 mg/dL for period 1, 2, 3, and 4, respectively; SEM = 1.26). In addition, the concentration of cortisol (7.62 and 6.59 ng/mL; SEM = 0.404), thyroxine (5.83 and 5.00 µg/dL; SEM = 0.140), and heat shock protein (136 and 146 ng/mL for week 2 and 8, respectively; SEM = 4.0) differed between weeks (p < 0.05). In conclusion, the lack of interaction between breed and period with different HLI conditions suggests that levels of these blood constituents were not highly related to resilience to high HLI.

“…Blood biochemical parameters are important indicators of physiological changes in the animal body in response to adverse environmental conditions [ 53 ]. HS significantly decreased blood glucose (major metabolites of energy metabolism) and BUN concentrations in Holstein and Jersey steers, which was speculated to be due to reduced feed intake [ 54 , 55 ]. In contrast, increased BUN in sheep has been reported during HS due to reduced blood flow to the kidneys [ 56 ].…”

Section: Discussionmentioning

confidence: 99%

Higher Concentration of Dietary Selenium, Zinc, and Copper Complex Reduces Heat Stress-Associated Oxidative Stress and Metabolic Alteration in the Blood of Holstein and Jersey Steers

Son

Kim

Islam

et al. 2022

This study investigated the influence of high concentrations of dietary minerals on reducing heat stress (HS)-associated oxidative stress and metabolic alterations in the blood of Holstein and Jersey steers. Holstein steers and Jersey steers were separately maintained under a 3 × 3 Latin square design during the summer conditions. For each trial, the treatments included Control (Con; fed basal TMR without additional mineral supplementation), NM (NRC recommended mineral supplementation group; [basal TMR + (Se 0.1 ppm + Zn 30 ppm + Cu 10 ppm) as DM basis]), and HM (higher than NRC recommended mineral supplementation group; [basal TMR + (Se 3.5 ppm + Zn 350 ppm + Cu 28 ppm) as DM basis]). Blood samples were collected at the end of each 20-day feeding trial. In both breeds, a higher superoxide dismutase concentration (U/mL) along with lower HSP27 (μg/L) and HSP70 (μg/L) concentrations were observed in both mineral-supplemented groups compared to the Con group (p < 0.05). The HM group had significantly higher lactic acid levels in Jersey steers (p < 0.05), and tended to have higher alanine levels in Holstein steers (p = 0.051). Based on star pattern recognition analysis, the levels of succinic acid, malic acid, γ-linolenic acid, 13-methyltetradecanoic acid, and tyrosine decreased, whereas palmitoleic acid increased with increasing mineral concentrations in both breeds. Different treatment groups of both breeds were separated according to the VIP scores of the top 15 metabolites through PLS–DA analysis; however, their metabolic trend was mostly associated with the glucose homeostasis. Overall, the results suggested that supplementation with a higher-than-recommended concentration of dietary minerals rich in organic Se, as was the case in the HM group, would help to prevent HS-associated oxidative stress and metabolic alterations in Holstein and Jersey steers.