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You searched for subject:(heat increment). Showing records 1 – 2 of 2 total matches.

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University of Georgia

1. Pacetti, Lani Melissa. Using dietary heat increment to alter energy use in dairy cows during hot weather.

Degree: 2014, University of Georgia

Thirty-two lactating Holstein cows averaging 169 ± 35 DIM were used to determine changes in energy use due to ration heat increment (HI) content under heat stress conditions. Dietary treatments were high HI ad libitum (HA), low HI ad libitum (LA), and low HI at restricted caloric intake (LR). The LR cows were paired and restricted to HA daily NEL intake (Mcal/100 kg BW). The high HI diet was formulated with more forage and fibrous byproducts, whereas the low HI diet contained more starch and fat from byproducts. Milk yield, milk composition, and energy-corrected milk yield were similar for treatments. Milk yield and energy-corrected milk yield per kg DMI were greater for LR compared with HA. Total energy efficiency was greater for LR than for HA and LA treatment groups. Data indicates that HI is useful for reducing heat stress and improving energy efficiency in dairy cattle during heat stress.

Subjects/Keywords: heat stress; heat increment; dairy; energy use

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Pacetti, L. M. (2014). Using dietary heat increment to alter energy use in dairy cows during hot weather. (Thesis). University of Georgia. Retrieved from http://hdl.handle.net/10724/23487

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Pacetti, Lani Melissa. “Using dietary heat increment to alter energy use in dairy cows during hot weather.” 2014. Thesis, University of Georgia. Accessed April 14, 2021. http://hdl.handle.net/10724/23487.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Pacetti, Lani Melissa. “Using dietary heat increment to alter energy use in dairy cows during hot weather.” 2014. Web. 14 Apr 2021.

Vancouver:

Pacetti LM. Using dietary heat increment to alter energy use in dairy cows during hot weather. [Internet] [Thesis]. University of Georgia; 2014. [cited 2021 Apr 14]. Available from: http://hdl.handle.net/10724/23487.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Pacetti LM. Using dietary heat increment to alter energy use in dairy cows during hot weather. [Thesis]. University of Georgia; 2014. Available from: http://hdl.handle.net/10724/23487

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


University of Oulu

2. Laurila, M. (Mirja). Thermoregulatory consequences of starvation and digestion in birds.

Degree: 2005, University of Oulu

Abstract In homeothermic birds and mammals, several thermoregulatory adaptations have evolved for surviving in unstable, food-restricted conditions. This study focuses on two adaptive mechanisms in pigeons (Columba livia) and quails (Coturnix coturnix japonica): hypothermia and the adaptive use obligatory heat production connected with feeding and digestion. The plasticity of the hypothermic response in fed and fasted birds and birds with restricted feeding was studied in laboratory and outdoor winter conditions. The other objective was to study adaptive timing of digestion, and substitution of facultative thermogenesis by obligatory heat production in cold and at thermoneutrality. The results showed that fasting has a strong influence on the level of nocturnal hypothermia in laboratory conditions: hypothermia becomes progressively deeper when fasting continues. In outdoor conditions, ambient temperature and predation risk modulated the daily body temperature (Tb) pattern of fasting pigeons. In very cold conditions, diurnal Tb of fasted birds also dropped below the normal level of the active phase. Predation risk prevented diurnal hypothermia but also attenuated the depth of nocturnal hypothermia in fasting pigeons. This study provides the first empirical effects of predation risk on hypothermia in starving birds. The study suggests that the presence of crop in pigeons allows adaptive timing of digestion. At thermoneutrality, peak digestion appeared late in the dark phase in birds with fed in the morning. Because the Tb of the birds increases to diurnal levels late in the dark phase, this obligatory heat from digestion can be used to aid re-warming by such timing. On other hand, the results of this study were partly opposite to the classical model of thermoregulatory substitution. In line with the classical model, a postprandial increase in metabolic rate (heat increment of feeding, HIF) was seen at thermoneutrality but not in cold. However, electromyographic measurements showed that there was no postprandial decrease in the intensity of shivering in the fed birds in cold. This indicates that true thermoregulatory substitution may be less common than assumed and suggests a role for facultative thermogenesis in HIF.

Subjects/Keywords: birds; digestion; facultative thermogenesis; fasting; heat increment of feeding (HIF); hypothermia; obligatory thermogenesis; predation; shivering; substitution

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Laurila, M. (. (2005). Thermoregulatory consequences of starvation and digestion in birds. (Doctoral Dissertation). University of Oulu. Retrieved from http://urn.fi/urn:isbn:9514277147

Chicago Manual of Style (16th Edition):

Laurila, M (Mirja). “Thermoregulatory consequences of starvation and digestion in birds.” 2005. Doctoral Dissertation, University of Oulu. Accessed April 14, 2021. http://urn.fi/urn:isbn:9514277147.

MLA Handbook (7th Edition):

Laurila, M (Mirja). “Thermoregulatory consequences of starvation and digestion in birds.” 2005. Web. 14 Apr 2021.

Vancouver:

Laurila M(. Thermoregulatory consequences of starvation and digestion in birds. [Internet] [Doctoral dissertation]. University of Oulu; 2005. [cited 2021 Apr 14]. Available from: http://urn.fi/urn:isbn:9514277147.

Council of Science Editors:

Laurila M(. Thermoregulatory consequences of starvation and digestion in birds. [Doctoral Dissertation]. University of Oulu; 2005. Available from: http://urn.fi/urn:isbn:9514277147

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