Physiological and Production Responses of Dairy Cattle to a Shade Structure in a Subtropical Environment

Abstract:The main purpose of this study is to assess the relationship between four bioclimatic indices for cattle (environmental stress, heat load, modified heat load, and respiratory rate predictor indices) and three main milk components (fat, protein, and milk yield) considering uncertainty. The climate parameters used to calculate the climate indices were taken from the NASA-Modern Era Retrospective-Analysis for Research and Applications (NASA-MERRA) reanalysis from 2002 to 2010. Cow milk data were considered for the same period from April to September when the cows use the natural pasture. The study is based on a linear regression analysis using correlations as a summarizing diagnostic. Bootstrapping is used to represent uncertainty information in the confidence intervals. The main results identify an interesting relationship between the milk compounds and climate indices under all climate conditions. During spring, there are reasonably high correlations between the fat and protein concentrations vs. the climate indices, whereas there are insignificant dependencies between the milk yield and climate indices. During summer, the correlation between the fat and protein concentrations with the climate indices decreased in comparison with the spring results, whereas the correlation for the milk yield increased. This methodology is suggested for OPEN ACCESSClimate 2015, 3 877 studies investigating the impacts of climate variability/change on food and agriculture using short term data considering uncertainty.

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“…Neither Knapp and Grummer [40] nor Roman-Ponce et al [41] found any significant relationship between fat reduction and heat stress.…”

Section: Climatic Index and Milk Parameter Statisticsmentioning

confidence: 86%

A Survey of the Relationship between Climatic Heat Stress Indices and Fundamental Milk Components Considering Uncertainty

Milani

Hense

Rahmani

et al. 2015

Climate

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“…Heat stress environments have been associated with depressions in milk fat percentages [26]. However, other authors [15,27] found no significant decrease in fat percentage for cows under heat stress. The depressed fat percentage observed in the present study could be attributed to the decrease in forage intake (17%) which may have resulted in an inadequate fiber level in the diet to maintain normal rumen function.…”

Section: Environmental Conditions During the Experimental Periodsmentioning

confidence: 97%

The relationship of temperature-humidity index with milk production of dairy cows in a Mediterranean climate

et al. 2002

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-Two experiments were conducted using lactating Friesian-Holstein cows to measure the effects of heat stress, using temperature-humidity index (THI), on milk production, milk composition and dry matter intake (DMI) under the Mediterranean climate. These trials were carried out in two periods differing in average THI values (68 ± 3.75 vs. 78 ± 3.23 for the spring and summer periods, respectively). Daily THI was negatively correlated to milk yield (r = -0.76) and feed intake (r = -0.24). When the THI value increased from 68 to 78, milk production decreased by 21% and DMI by 9.6%. Milk yield decreased by 0.41 kg per cow per day for each point increase in the THI values above 69. Milk fat (3.24 vs. 3.58%) and milk protein (2.88 vs. 2.96%) were lower for the summer group. THI was positively correlated to respiration rate (RR) (r = 0.89), heart rate (HR) (r = 0.88), rectal temperature (RT) (r = 0.85) and cortisol (0.31), and negatively with free thyroxin (-0.43). As the THI values increased from 68 to 78, RT increased by 0.5 o C, HR by 6 beats, and RR by 5 inspirations per min. The average concentration of cortisol increased from 21.75 to 23.5 nmol·L -1 (P > 0.05), while that of free thyroxin decreased from 15.5 to 14.5 pmol·L -1 , (P > 0.05). Summer heat stress reduced milk yield and DMI, altered milk composition and affected the physiological functions of confined lactating Holstein cows managed under Mediterranean climatic conditions. dairy cow / temperature-humidity index / milk production / intake / physiology Résumé -Relation entre l'index température-humidité et la production laitière chez la vache Frisonne élevée sous un climat méditerranéen. Deux essais ont été menés sur des vaches laitières Frisonne-Holstein pour étudier l'effet du stress thermique sur la production et la composition du lait et sur l'ingestion de la matière sèche sous un climat méditerranéen. Ces essais ont été réalisés en deux périodes qui diffèrent seulement par leurs valeurs d'index température-humidité (THI) (68 ± 3,75 et 78 ± 3,23 pour le printemps et l'été, respectivement). Le THI journalier est négativement corrélé à la production laitière (r = -0,76) et à l'ingestion (r = -0,24). Lorsque la valeur THI est passée de 68 à 78, la production laitière a diminué de 21 % et la matière sèche ingérée de 9,6 %. Pour chaque unité d'augmentation du THI au delà de 69, la production laitière chute de 0,41 kg par vache par jour. Les teneurs du lait en matière grasse (3,24 et 3,58 %) et en protéines (2,88 et 2,96 %) étaient plus faibles (P < 0,05) pendant la période estivale. Le THI est positivement corrélé à la température rectale (r = 0,89), aux rythmes cardiaque (r = 0,88) et respiratoire (r = 0,85) et au cortisol (r = 0,31), mais né-gativement avec la thyroxine libre (r = -0,43). La variation de la valeur THI de 68 à 78 a engendré une augmentation de la température rectale, de la fréquence cardiaque et du rythme respiratoire de 0,5 o C, 6 battements par min et 5 inspirations par min, respectivement. La concentration plasmatique moyenne ...

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“…Heat stress decreases the intensity and duration of oestrus, which in turn reduces both the number of inseminations and the pregnancy rates [23]. Heat stress alters the concentration of circulating hormones by increasing the circulating concentration of corticosteroids [24] and by reducing progesterone concentration [25]. The viability of prefixation embryos is reduced [26], and the uterine environment is altered by a decreased blood flow [27] and increased uterine temperature [28].…”

Section: Effects Of Heat Stress On Reproductionmentioning

confidence: 99%

“…In an attempt to minimize these effects, modifications to dairy cattle housing environments have been implemented to alleviate thermal stressors and improve cow comfort, through the use of shade, fans, sprinklers, and evaporative cooling [11,37,40]. These methods can enhance pregnancy rates significantly [24,41].…”

Section: Effects Of Heat Stress On Reproductionmentioning

confidence: 99%

Alleviating Heat Stress Leads to Improved Cow Reproductive Performance

Suadsong¹

2012

Milk Production - An Up-to-Date Overview of Animal Nutrition, Management and Health

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Physiological and Production Responses of Dairy Cattle to a Shade Structure in a Subtropical Environment

Cited by 161 publications

References 29 publications

A Survey of the Relationship between Climatic Heat Stress Indices and Fundamental Milk Components Considering Uncertainty

A Survey of the Relationship between Climatic Heat Stress Indices and Fundamental Milk Components Considering Uncertainty

The relationship of temperature-humidity index with milk production of dairy cows in a Mediterranean climate

Alleviating Heat Stress Leads to Improved Cow Reproductive Performance

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