Effect of Ad Libitum or Force-Feeding of Two Rations on Lactating Dairy Cows Subject to Temperature Stress

Wayman, O.; Johnson, H. D.; Merilan, C.P.; Berry, Isabelle

doi:10.3168/jds.s0022-0302(62)89658-1

Cited by 54 publications

(19 citation statements)

References 6 publications

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“…This reflects a greater energy demand on the animals during heat stress as has been reported (McDowell, 1968;McDowell et aI., 1969;Wayman et al, 1962). There were no treatment differences in calcium, inorganic phosphorus or protein.…”

Section: Stress (Hs)supporting

confidence: 48%

Short term post-partum heat stress in dairy cows

1980

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ABSTRACT. --Since many dairy cows calve during late summer, the objective was to determine if heat stress immediately post-partum would (1) alter metabolism, thus, increasing susceptibility to metabolic disorders, (2) affect lactation and/or (3) affect reproduction. Forty four cows, calving during late summer, were paired with one member of each pair stressed (HS) for the first 10 post-partum days in a hot barn. Controls (CC) were kept in a cooled section of the barn. Plasma drawn weekly for 7 weeks was analyzed in an autoanalyzer for calcium, inor. phosphorus,__protein, glucose and cholesterol and by radioimmunoassay for cortisol a rid-progesterone. Ovaries and uteri were palpated weekly. Rectal temperatures were significant higher for HS during the first 10 post-partum days. No significant effects on plasma constituents were observed during the 10-day treatment period. For the 7-week period, glucose and cholesterol were lower in HS, as were cyclic peaks of progesterone and cortisol. Both calcium and inorganic phosphorus remained clinically low for the 7 weeks, but no treatment effects were seen. Uteri of HS involuted more rapidly than the CC. Treatment did not affect reproductive efficiency. Lactation milk yields did not differ, but milk fat percent was lower in HS. Heat stress immediately post-partum altered lipid metabolism, but the animal's compensatory mechanisms prevented reduction in milk production or reproductive efficiency.

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Section: Stress (Hs)supporting

confidence: 48%

Short term post-partum heat stress in dairy cows

1980

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“…The net energy required by both groups was higher during early, mid-and lower in late stage of lactation, indicating that efficiency of utilization of energy for milk production is governed by both environmental temperature and stage of lactation (Krishnamohan et al 1975). The high environmental temperature caused a significant decrease in efficiency of energy utilization for milk production (Wayman et al 1962). In the present study in non-cooled animals, energy costs would be spent mostly for heat dissipation mechanisms, causing low efficiency of energy utilization for milk production.…”

Section: Discussionmentioning

confidence: 99%

Effects of evaporative cooling on the regulation of body water and milk production in crossbred Holstein cattle in a tropical environment

2008

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The aim of this study was to determine how evaporative cooling modifies body function with respect to water metabolism and other variables relevant to milk synthesis in crossbred cattle. The study was conducted on two groups of 0.875HF:0.125RS crossbred Holstein cattle (87.5%) housed in an open-sided barn with a tiled roof (non-cooled animals) and in a close-sided barn under an evaporative cooling system (cooled animals). The maximum ambient temperature and relative humidity for the non-cooled group were 33 degrees C and 61%, with the corresponding values for the evaporatively cooled barn being 28 degrees C and 84%, respectively. The temperature humidity index (THI) of under non-cooled conditions was higher (P < 0.05) than that in the cooled barn. Rectal temperatures and respiration rates of non-cooled animals were higher (P < 0.05) than those of cooled animals. Daily dry matter intake (DMI) of cooled animals was higher while water intakes were lower (P < 0.05) than those of non-cooled animals. The mean absolute values of plasma volume, blood volume, and extracellular fluid (ECF) of cooled animals were significantly higher (P < 0.05) than those of non-cooled animals throughout all stages of lactation. Milk yields of cooled animals were higher by 42%, 36% and 79% on average than those of non-cooled animals during early-, mid- and late-lactation, respectively. The decline in milk yields as lactation advances was markedly apparent in late-lactating non-cooled animals, while no significant changes in milk composition at different stages of lactation were observed in either group. Mean arterial plasma concentrations, arteriovenous concentration differences (A-V differences) and the extraction ratio across the mammary gland for acetate, glucose and triglyceride of cooled animals were not significantly different compared with values for non-cooled animals. No differences were seen in plasma hormonal levels for triiodotyronine (T(3)) and insulin-like growth factor-1 (IGF-1), but plasma cortisol and thyroxine (T(4)) levels tended to be lower in non-cooled animals. This study suggests that low cooling temperature accompanied by high humidity influences a galactopoietic effect, in part through increases in ECF, blood volume and plasma volume in association with an increase in DMI, which partitions the distribution of nutrients to the mammary gland for milk synthesis. Cooled animals were unable to maintain high milk yield as lactation advances even though a high level of body fluids was maintained during long-term cooled exposure. The decline in milk yield, coinciding with a decrease in net energy for lactation as lactation advances, could be attributed to a local change within the mammary gland.

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“…The prevailing view is that the reduction of milk yield under heat stress is the consequence of reduced appetite (Collier et al, 1982;Beede and Collier, 1986;Armstrong, 1994;West, 1994). However, this view is challenged by evidences for a direct relationship between heat stress and the process of milk secretion (Wayman et al, 1962;Bandanrannayaka and Holmes, 1976;Barash et al, 1996). Force-feeding of hyperthermic cows to the level recorded in normothermic cows (Wayman et al, 1962), or restricting the intake of normothermic cows to the level recorded in hyperthermic cows (Bandanrannayaka and Holmes, 1976), did not abolished the differences in milk yield between normothermic and hyperthermic cows.…”

Section: Introductionmentioning

confidence: 95%

“…However, this view is challenged by evidences for a direct relationship between heat stress and the process of milk secretion (Wayman et al, 1962;Bandanrannayaka and Holmes, 1976;Barash et al, 1996). Force-feeding of hyperthermic cows to the level recorded in normothermic cows (Wayman et al, 1962), or restricting the intake of normothermic cows to the level recorded in hyperthermic cows (Bandanrannayaka and Holmes, 1976), did not abolished the differences in milk yield between normothermic and hyperthermic cows. More recently, Barash et al (1996) found by analyzing the Israeli national records that the lowest annual milk yield of Holsteins occurs in cows that are giving birth during the summer.…”

Section: Introductionmentioning

confidence: 97%

Lactation and body weight of dairy cows: interrelationships among heat stress, calving season and milk yield

Maltz¹,

Kroll²,

Barash³

et al. 2000

J. Anim. Feed Sci.

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How the interactions among heat stress, calving season and milk yield (MY) affects lactation and body weight (BW) curves was studied by analyzing the daily records of MY and BW of dairy cows. The summer calving cows (SC) attained minimal BW sooner than winter calving cows (WC), the differences between high yielding (HY; MY>40 1/d) SC and WC being greater than differences between low yielding (LY; MY<40 1/d). The minimal BW was lower in all SC than in WC and this could be related to the differences between the HY cows. MY peak was higher in all WC than in all SC, similar in LY cows among the two treatments, and higher in HY WC than in HY SC. The 4.4% differences in MY during the first 40 wk postpartum between all WC (8960 1) and all SC (8568) could be related to 8.0% differences between HY WC (10444 1) and HY SC (9604 1). During the summer peak MY occurred later than during the winter irrespective of the production level. We have shown that heat stress during early lactation affects the entire lactation and BW curves in dairy cows, and that heat stress negatively interacts with MY.

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Effect of Ad Libitum or Force-Feeding of Two Rations on Lactating Dairy Cows Subject to Temperature Stress

Cited by 54 publications

References 6 publications

Short term post-partum heat stress in dairy cows

Short term post-partum heat stress in dairy cows

Effects of evaporative cooling on the regulation of body water and milk production in crossbred Holstein cattle in a tropical environment

Lactation and body weight of dairy cows: interrelationships among heat stress, calving season and milk yield

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