Comparison of two variants of the Fick principle for estimation of mammary blood flow in dairy cows fed two levels of dry matter intake

2001 ◽  
Vol 81 (1) ◽  
pp. 57-63 ◽  
Author(s):  
D. Pacheco-Rios ◽  
D. D. S. Mackenzie ◽  
W. C. McNabb
Keyword(s):  
Blood Flow ◽  
Mammary Gland ◽  
Dairy Cows ◽  
Dry Matter ◽  
Tritiated Water ◽  
Sampling Period ◽  
Experimental Period ◽  
Flow Meters ◽  
Fick Principle ◽  
Ad Libitum

The estimation of the mammary blood flow (MBF) is an important component of studies of the utilization of metabolites by the mammary gland of lactating animals. Although there are several flow meters available to measure MBF by direct contact with the vessels perfusing the mammary gland, their use is limited mainly by the surgical preparation required for their implantation. For that reason, the application of the Fick principle was assessed as a mean to estimate MBF as part of a study on amino acid utilization by the mammary gland in three pasture-fed dairy cows at either ad libitum or restricted dry matter intakes. Two methods based on the Fick principle were assessed, namely, arterio-venous differences of amino acids (methionine: Met or phenylalanine+tyrosine: Phe + Tyr) and tritiated water (TOH). The estimated MBF was not significantly different for the Met and Phe + Tyr methods (average of 8.1 and 8.8 L min–1, respectively). The TOH method yielded a significantly lower (P < 0.05) estimate of blood flow (average of 5.3 L min–1). Using the Met and Phe+Tyr methods, the MBF was lower during the period of dietary restriction compared with the ad libitum treatment (average of 9.4 and 7.5 L min–1, respectively). In contrast, the TOH method resulted in a numerically higher MBF for the restricted group (5.7 vs. 4.9 L min–1). The short sampling period a nd the loss of indicator in the TOH method appear to be a disadvantage for extrapolating the estimated values to balance studies with lactating cows involving longer periods of time. The estimated values obtained using the Met or Phe + Tyr appear to be re presentative of the MBF during the experimental period. Therefore, any of these methods (Met, Phe + Tyr) may be used alone or in combination as an alternative to flow meters in studies of mammary metabolism. Key words: Dairy cows, mammary blood flow, Fick principle

The effect of restriction of pasture intake in late lactation on the milk production and body condition of dairy cows

1980 ◽  
Vol 20 (105) ◽  
pp. 389 ◽  
Author(s):  
KR King ◽  
CR Stockdale ◽  
IF Patterson
Keyword(s):  
Dairy Cows ◽  
Body Condition ◽  
Dry Matter ◽  
Body Condition Score ◽  
Experimental Period ◽  
Dry Matter Intake ◽  
Pasture Production ◽  
Condition Score ◽  
Ad Libitum ◽  
Daily Milk Yield

The effect of restricting the intake of pasture on the performance of dairy cows was studied in two 28-day phases in the eighth and ninth months of lactation. Intakes ranged from 12.4 to 4.9 kg of dry matter/cow day-1. After the 28-day restriction phases, all cows were grazed ad libitum at pasture. Production of milk, butterfat, protein and solids-not-fat all declined linearly with reduction in intake (0.569, 0.0286, 0.0206 and 0.0525 kg per kg of dry matter intake, respectively). Butterfat concentration increased curvilinearly with reduction in intake, but there was no effect on protein and solids-not-fat concentrations. In addition to the decreased production, there was a decrease in body condition score of 0.160 units for each kg reduction in dry matter intake. During the post-experimental period, with ad libitum grazing, cows that had previously been restricted recovered most of their daily milk yield and some of their body condition. The cows in this experiment required an extra 35 kg of dry matter to produce an extra kg of butterfat, but this efficiency ignores potential extra production in the following lactation from improved body condition.

scholarly journals Effect of Ruminally-protected leucine supplement on milk yield and plasma amino acids in dairy cows

2008 ◽  
Vol 17 (4) ◽  
pp. 351 ◽  
Author(s):  
L. KRÍZOVÁ ◽  
J. TRINÁCTÝ ◽  
M. RICHTER
Keyword(s):  
Amino Acids ◽  
Milk Yield ◽  
Dry Matter ◽  
Milk Protein ◽  
Experimental Period ◽  
Dry Matter Intake ◽  
Plasma Amino Acids ◽  
Maize Silage ◽  
Milk Protein Content ◽  
Ad Libitum

The aim of this study was to determine the influence of leucine supplement in the form of rumen-protected tablets on milk yield and composition and plasma amino acids in four high-yielding lactating Holstein cows. The experiment was carried out as a cross-over procedure and was divided into 4 periods of 14 d (10 d preliminary period and 4 d experimental period). Cows were fed ad libitum a diet based on maize silage, lucerne hay and a supplemental mixture. The diet, defficient in methionine, lysine, and leucine, was supplemented with methionine+lysine (Control) or methionine+lysine+leucine (Leu) in rumen protected form. The dry matter intake, milk yield and milk yield expressed in energy corrected milk did not differ significantly between the treatments. Milk protein content and yield did not show statistically significant variation. The contents and yield of casein, fat, lactose and urea were unaffected by the treatment. Blood metabolites did not vary between the treatments. The introduction of Leu resulted in higher plasma levels of proline (p

Proteomic analysis of the effects of lutein on mammary gland metabolism in dairy cows

2018 ◽  
Vol 85 (2) ◽  
pp. 152-156
Author(s):  
Caihong Wang ◽  
Chong Wang ◽  
Jianxin Liu ◽  
Hongyun Liu
Keyword(s):  
Blood Flow ◽  
Mammary Gland ◽  
Fatty Acid ◽  
Dairy Cows ◽  
Control Diet ◽  
Differentially Expressed ◽  
Acid Oxidation ◽  
Differentially Expressed Proteins ◽  
Proteomic Approach ◽  
Increased Blood Flow

The aim of the research reported in this Research Communication was to identify differentially expressed proteins in dairy cows with normal and lutein diet and to elucidate the mechanisms of lutein-induced effects on bovine mammary gland metabolism using a comparative proteomic approach. Thirty-three differentially expressed proteins were identified from mammary gland of control diet-fed and lutein diet-fed dairy cows. Among these proteins, 15 were upregulated and 18 were downregulated in the lutein group. Functional analysis of the differentially expressed proteins showed that increased blood flow, depressed glycolysis, enhanced lactose anabolism, decreased fatty acid oxidation and up-regulated beta lactoglobulin expression were connected with lutein addition. These results suggested that the increased blood flow, reduced glucose catabolism, enhanced capacity for milk lactose synthesis, depressed fatty acid catabolism and increased expression of antioxidantion related protein may be the prime factors contributing to the increased milk production and enhanced immune status in lutein-fed dairy cows. This study provides molecular mechanism of dietary lutein in regulating lactation of dairy cows.

The role of the mammary gland during heat stress

2019 ◽  
Author(s):  
◽  
Ricardo Oliveira Rodrigues
Keyword(s):  
Blood Flow ◽  
Heat Stress ◽  
Mammary Gland ◽  
Dairy Cows ◽  
Prolonged Exposure ◽  
Transcriptional Profiling ◽  
Mammary Tissue ◽  
Secretory Cells ◽  
University Of Missouri ◽  
Lactating Dairy Cows

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Disruptive effects of climate change, such as increasing environmental temperature, have direct impacts on economic viability and efficiency of food production. In lactating dairy cows, heat stress reduces milk production and alters function of mammary secretory cells, at least partly by disturbing local protein metabolism. We hypothesized that hyperthermia would not only reduce mammary blood flow but would also reduce mammary extraction of nutrients from blood. In addition, we hypothesized that transcriptional profiling of mammary tissue would reveal disruption of cellular homeostasis. Our objective was to determine the effects of hyperthermia on mammary function. More specifically, we aimed to profile mammary blood flow and the changes in mammary transcriptome of heat-stressed lactating dairy cows. We investigated the effects of early and prolonged exposure of lactating dairy cows to hyperthermia by exposing cows to programmed constantly elevated temperature and humidity to induce and maintain body temperature approximately 1[degree]C above normal. Experiments were conducted to evaluate the production responses of hyperthermic lactating dairy cows, to characterize total and nutritive mammary blood flow, and to elucidate the regulation of mammary function during early and prolonged exposure to hyperthermia. Results from these studies established that 1) hyperthermia reduces total and nutritive mammary blood flow, limiting nutrient disappearance across the mammary gland; 2) hyperthermia does not induce shunting of blood away from the gland; 3) hyperthermia affects mammary tissue transcriptome, mainly altering processes associated with ECM and cell adhesion; 4) the effects of exposure to prolonged heat stress on mammary gene expression are distinct from the effects of feed restriction, in lactating dairy cows; and 5) mammary function is reestablished within 8 days after cessation of heat stress.

scholarly journals Effect of restricted feeding in the far-off period on performance and metabolic status of dairy cows

2014 ◽  
Vol 14 (1) ◽  
pp. 89-100
Author(s):  
Włodzimierz Nowak ◽  
Robert Mikuła ◽  
Ewa Pruszyńska-Oszmałek ◽  
Barbara Stefańska ◽  
Paweł Maćkowiak ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Dry Matter ◽  
Transition Period ◽  
Restricted Feeding ◽  
Lactating Cows ◽  
Fibre Diet ◽  
System Recommendation ◽  
Holstein Friesian ◽  
Ad Libitum ◽  
Ad Libitum Feeding

AbstractThe aim of the study was to investigate experimentally the effects of restricted or ad libitum feeding in the far-off period on performance of dairy cows. Two groups of Polish Holstein-Friesian cows having 19 animals in each group were allotted to two planes of nutrition in the far-off period from -56 to -22 days. The ADLIB group was fed ad libitum (DMI 12.9 kg) while in the RES group the dry matter intake was restricted by 3 kg DM compared to the average dry matter during the last 7 days in the ADLIB group. Average daily energy intake decreased from 8.90 UFL in the ADLIB to 6.83 UFL in the RES group. In the close-up period and after parturition, the cows of both groups were given the same diet. In restrictively fed cows, there was a tendency to a greater decrease in BCS during both the dry period (P=0.09) and lactation (P=0.07). After parturition milk production, fertility indices and blood concentration of IGF-1, insulin and glucose were not significantly affected by the far-off treatment. In the RES group, lower BHBA 3 days before calving and on day 5 of lactation and lower NEFA on day 28 of lactation were recorded. Also in this group higher levels of glucose 3 days before calving, triiodothyronine (T3) on days -30 and 5, and thyroxine (T4) on days -3 and 28 were observed. It is concluded that restricted feeding in the far-off period positively affected blood indicators of lipomobilization during the transition period, but had little effect on performance of lactating cows. In spite of low energy, high-fibre diet offered ad libitum in the faroff period resulted in the energy overfeeding compared to the INRA system recommendation.

Effect of dietary soybean or sunflower seeds on milk production, milk fatty acid profile and yield of conjugated linoleic acid

2004 ◽  
Vol 84 (1) ◽  
pp. 113-124 ◽  
Author(s):  
O. Dayani ◽  
G. Ghorbani ◽  
T. Entz ◽  
C. M. Ross ◽  
M. A. Shah ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Linoleic Acid ◽  
Dairy Cows ◽  
Conjugated Linoleic Acid ◽  
Sunflower Seed ◽  
Dry Matter ◽  
Experimental Period ◽  
Barley Grain ◽  
Sunflower Seeds ◽  
Barley Silage

Eight cows in mid-lactation were used to determine the effects of feeding diets containing soybeans (SBS) or sunflower seed (SFS) on conjugated linoleic acid (CLA) yield and concentration in milk during two 3-wk periods. All cows were fed a standard pre-trial diet for 2 wk, before assignment to treatment diets in both periods of the 2 × 2 cross-over design used in the study. The two treatment diets contained on a dry matter (DM) basis: (1) SBS: 20% barley silage, 34.7% barley grain, 30% alfalfa cube, 13% crushed soybean seed and 0.36% sunflower oil, and (2) SFS: 17% barley silage, 34.6% barley grain, 40% sunflower seed incorporated into alfalfa cubes (cubes comprised 18% whole sunflower seed and 82% alfalfa hay), and 6.5% heat-treated soybean meal. The ingredients in the two diets were adjusted so that they would provide similar levels of energy (1.5 MCal kg-1) and have similar nutrient composition with regard to protein (16.7%), ether extract (5.2%) and fibre components (41%). Milk samples were collected, on 2 d prior to initiation of treatment diets and on days 6, 7, 13, 1 4, 20 and 21 of each experimental period. Cholecystokinin and insulin concentrations in blood samples collected at the start and end of each experimental period indicated no significant differences. Dry matter and net energy intake of cows fed the SBS and SFS were 23.3 and 21.4 ± 0.9 kg d-1; 34.4 and 31.6 ± 1.4 Mcal d-1, respectively, and in vitro volatile fatty acid concentration after 24 h of incubation was 123.3 and 114.7 ± 1.3 mM, respectively, and lower (P < 0.05) for the SFS diet. Milk, milk fat, protein and lactose yields from cows fed the SBS and SFS diets were similar (32.9 and 32.0 ± 2.4; 1.10 and 0.97 ± 0.07; 1.05 and 1.00 ± 0.05; 1.46 and 1.39 ± 0.12, respectively), but the CLA cis-9, trans-11 concentrations in the milk from cows fed the SBS and SFS diets were 4.05 and 7.28 mg g-1 of lipid and resulted in 66% higher (P < 0.01) CLA yield (g d-1) in milk for cows fed the SFS diet. This study confirmed that feeding sunflower seeds as a component of a hay cube increased CLA yield in the milk of dairy cows without affecting yields of other milk components. Key words: Dairy cows, sunflower, soybeans, milk production, conjugated linoleic acid

Hay supplements to overcome underfeeding of dairy cows. 2. Late lactation

1981 ◽  
Vol 21 (109) ◽  
pp. 157 ◽  
Author(s):  
KR King ◽  
CR Stockdale
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Body Condition ◽  
Dry Matter ◽  
Nutritive Value ◽  
Dry Matter Intake ◽  
High Quality ◽  
Stage Of Lactation ◽  
Ad Libitum ◽  
Ration Composition

The effect of hay supplementation on the performance of dairy cows on a restricted intake of paspalum-dominant perennial pasture was studied in two 21 -day periods in the eighth and ninth months of lactation. In each period, there were three groups fed pasture only at mean intakes of 15.2, 11.5 and 7.3 kg/cow day-1, two groups fed at similar pasture restriction levels and supplemented with hay ad libitum, and one further group fed an average of 7.3 kg of pasture supplemented with only 4.3 kg of hay. The data were analyzed by regression, using total dry matter intake as the dependent variable, and pseudovariables were used to examine the effects of hay feeding. The relations between total dry matter intake and milk, butterfat, protein and solids-not-fat production, and change in body condition of dairy cows were not altered by ration composition. Milk production declined linearly by 0.66 kg and 0.31 kg/cow day-1 in the eight and ninth months of lactation, respectively, for each kg reduction in total dry matter intake. Similar responses were obtained for butterfat, protein and solids-not-fat production. Gain in body condition of the cows also decreased as total intake fell, but the relation was curvilinear and not affected by stage of lactation. It was concluded that high quality hay can be used to overcome shortages of paspalum-dominant perennial pasture in autumn, and that it has similar. nutritive value to pasture in terms of milk production and body condition.

Effects of replacing barley/soya with malt distillers grains (draff) in silage based complete diets for dairy cows

1989 ◽  
Vol 1989 ◽  
pp. 64-64
Author(s):  
J J Hyslop ◽  
D J Roberts
Keyword(s):  
Dairy Cows ◽  
Dry Matter ◽  
Previous Experiment ◽  
Distillers Grains ◽  
Dry Matter Intake ◽  
Design Experiment ◽  
Early Lactation ◽  
Grass Silage ◽  
Ad Libitum ◽  
Friesian Cows

In a previous experiment outlined at last year's conference (Hyslop and Roberts, 1988), it was demonstrated that replacement of a proprietary pelleted concentrate with malt distillers grains (draff), should be limited to 15% of total dry matter intake (DMI) when draff is offered in two feeds per day. However there is little evidence to validate such a limitation when draff is used as a concentrate replacement in complete diets. This experiment examined the effect of replacing barley/soya with draff plus additional minerals in silage based complete diets.In a cyclic changeover design experiment consisting of 4 three week periods, fifteen British Friesian cows in early lactation were offered five treatments. Cows were given ad libitum access to one of five complete diets based on grass silage (69 “D”). Draff plus additional minerals gradually replaced barley/soya at increasing rates in diets 0-4 respectively.

Production, composition and manufacturing properties of milk from dairy cows fed hay and silages made from either wilted herbage or formaldehyde-treated herbage

1979 ◽  
Vol 19 (98) ◽  
pp. 290 ◽  
Author(s):  
SC Valentine ◽  
RB Wickes
Keyword(s):  
Lactic Acid ◽  
Dairy Cows ◽  
Milk Fat ◽  
Dry Matter ◽  
Protein Production ◽  
Milk Protein ◽  
Heat Stability ◽  
Dairy Farmers ◽  
Ad Libitum ◽  
Production Composition

Hay, normal silage, and silages prepared from herbage either treated with formaldehyde at 0.8% of the dry matter (DM) ('formaldehyde silage') or wilted to 31 % DM ('wilted silage') were all made from grass/clover herbage cut at the same time. Dairy cows were offered the feeds ad libitum together with 4.5 kg of a barley-meatmeal concentrate daily. The chemical composition, digestibility and DM intake of the feeds together with the production, composition and manufacturing properties of the milk were determined. Compared with normal silage, the formaldehyde silage and wilted silage had lower concentrations of total titratable acids, butyric acid and lactic acid. The DM intakes (g day-1kg -0.75 by COWS of normal silage (126.7) and wilted silage (133.7) were higher than those of formaldehyde silage (114.0) and hay (103.6). The yield of milk fat (kg day-1) was greater for the cows offered wilted silage (0.62) and hay (0.62) than for cows offered normal silage (0.58). The yield of milk protein (kg day-1) was greater for the cows offered wilted silage (0.54) and hay (0.54) than for those offered formaldehyde silage (0.50) and normal silage (0.47). The percentages of milk protein and solids not fat, respectively, were greater for the cows offered wilted silage (3.37, 8.83), formaldehyde silage (3.30, 8.83) and hay (3.30, 8.89) than for those offered normal silage (3.1 5, 8.61). No differences were found between treatments in the heat stability characteristics of the milk. However, the milk of cows fed normal silage produced a firmer rennet curd than the milk from cows fed hay, wilted silage or formaldehyde silage. Cows offered normal silage, formaldehyde silage, wilted silage and hay had liveweight gains (kg day-1) of 0.1 6, 0.35, 0.86 and 0.04, respectively. It is concluded that although the milk fat and protein production of cows fed wilted silage and hay were similar, dairy farmers may prefer to feed wilted silage to dairy cows especially in late lactation, because of the ability of the cows to consume more wilted silage and consequently increase liveweight in preparation for the next lactation.

EFFECT OF LEVEL OF ALFALFA PELLETS ON INTAKE OF EARLY AND LATE HARVESTED TIMOTHY SILAGES OF DIFFERENT DRY MATTER CONTENT BY DAIRY COWS

1981 ◽  
Vol 61 (3) ◽  
pp. 633-638 ◽  
Author(s):  
P. L. BURGESS ◽  
J. W. G. NICHOLSON ◽  
E. A. GRANT
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Dry Matter ◽  
Milk Composition ◽  
Matter Content ◽  
Holstein Cows ◽  
Dry Matter Content ◽  
Timothy Grass ◽  
Ad Libitum

Two experiments were carried out, using 36 lactating Holstein cows, to determine the effect of three levels (0, 4.5 and 9.0 kg/day) of alfalfa pellets (AP) on the ad libitum consumption of early and late harvested timothy grass silages of different dry matter (DM) content. Cows consumed significantly more wilted than nonwilted silage DM for both the early and late harvested grass, although milk yields were similar for both groups. For the early harvested, wilted and nonwilted silages, feeding AP did not significantly depress silage DM intake until a level of 9.0 kg/day was reached. Total ration DM intake increased significantly with each increment of AP. With the late harvested silages, AP at the 9.0 kg/day level reduced nonwilted silage DM intake while with the wilted silage each increase of AP significantly lowered silage DM intake. Both the 4.5 and 9.0 kg/day of AP increased total DM consumption with the nonwilted silage but 9.0 kg/day of AP was required to significantly increase total DM intake for cows fed the late harvested, wilted silage. Milk yield and milk composition were not changed by the level of AP supplementation or the type of silage fed.

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