A randomized herd-level field study of dietary interactions with monensin on milk fat percentage in dairy cows

Large day-to-day variations in milk fat, particularly for the morning milkings, were observed in 36 Holstein cows. Changes in percent fat were gradual and produced wavelike patterns in a number of instances. Supplemental feeding of long hay had no effect on acetate/propionate ratio in rumen fluid, daily milk yield or weighted milk fat percentage. Key words: Dairy cows, milk, fat depression, hay

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Some effects of unsaturated oils given to dairy cows with rations of different roughage content

Journal of Dairy Research ◽

10.1017/s002202990001949x ◽

1971 ◽

Vol 38 (3) ◽

pp. 363-372 ◽

Cited By ~ 16

Author(s):

J. W. G. Nicholson ◽

J. D. Sutton

Keyword(s):

Fatty Acids ◽

Dairy Cows ◽

Milk Fat ◽

Volatile Fatty Acids ◽

Unsaturated Fatty Acids ◽

Basal Diet ◽

Fish Oils ◽

Fat Percentage ◽

Dietary Oil ◽

Effect Of Feeding

SummaryThree experiments were conducted to determine the effect of feeding polyunsaturated fish oils to dairy cows receiving rations of high, medium or low roughage content. In the rumen, the decreases in the proportion of acetic acid and increases in propionic acid induced by the oils became greater as the amount of oil given was increased but the magnitude of the response to any dose depended upon the composition of the basal diet. The effects on volatile fatty acids (VFA) proportions of small amounts of the oils (125–150 ml/day) were greatest with the low-roughage rations. With large doses of oil (375–450 ml/day) the responses were variable but it is concluded that, in general, changes in VFA proportions are least with low-roughage rations.The fat content of milk was more sensitive to dietary oil supplementation than were the rumen VFA proportions. When the unsaturated oils were given there was a decrease in milk fat percentage and an increase in the proportion of unsaturated fatty acids in the fat; there was also increased incorporation of fatty acids with more than 18 carbon atoms in the milk fat. The metabolism in the rumen tended to become adapted to the feeding of 150 ml/day of oil, the VFA pattern returning during the second and third week of supplementation to that observed before the addition of oil.

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Free endotoxins in the feces of lactating dairy cows

Canadian Journal of Animal Science ◽

10.4141/cjas10017 ◽

2010 ◽

Vol 90 (4) ◽

pp. 591-594 ◽

Cited By ~ 8

Author(s):

S. Li ◽

E. Khafipour ◽

D.O. Krause ◽

J.C. Rodriguez-Lecompte ◽

J.C. Plaizier

Keyword(s):

Blood Plasma ◽

Dairy Cows ◽

Milk Fat ◽

Serum Amyloid A ◽

Fat Percentage ◽

Amyloid A ◽

Ruminal Acidosis ◽

Limulus Amoebocyte Lysate ◽

Lactating Dairy Cows ◽

Dietary Content

A survey was conducted on 300 lactating dairy cows on 10 dairy farms to determine how risk factors for and symptoms of excessive grain feeding and subacute ruminal acidosis are associated with the concentrations of endotoxins in feces measured with the Limulus amoebocyte lysate test. Increases in days in milk and haptoglobin in blood plasma were associated with lower (P = 0.02) and higher (P = 0.02) fecal endotoxin, respectively. The five farms with a dietary neutral detergent fibre (NDF) content higher than 33.8% of DM had lower (P < 0.01) fecal endotoxin than those with a dietary NDF content lower than 33.8% of DM (31 790 vs. 69 276 endotoxin units (EU) g-1 of wet feces, P < 0.01). Parity, milk yield, milk fat percentage, milk protein percentage, the blood plasma concentration of serum amyloid A, and the dietary content of physically effective fibre were not associated with the fecal endotoxin concentration.

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Effects of feed delivery time on milk production and sorting of dairy cows

Canadian Journal of Animal Science ◽

10.4141/cjas08121 ◽

2009 ◽

Vol 89 (3) ◽

pp. 425-429

Author(s):

C J Furedi ◽

A D Kennedy ◽

J C Plaizier

Keyword(s):

Dairy Cows ◽

Milk Production ◽

Milk Fat ◽

Dry Matter ◽

Feeding Time ◽

Delivery Time ◽

Fat Percentage ◽

Medium Length ◽

Time Of Feeding ◽

Over Time

The effects of delivery time (0900 or 2100) of a diet consisting of 45% of dry matter as chopped hay and 55% of dry matter as concentrates on milk production of dairy cows were determined in a 6-wk experiment consisting of 3 wk of adaptation and 3 wk of sampling. Feed delivery time did not affect feed intake and milk production. Average milk fat percentage decreased from 2.14% during week 4 to 1.73% during week 6. The low milk fat could was assumed to be caused by the short dietary particle lengths, and could have prohibited effects of feeding time on milk production. The decrease in milk fat over time might have been due to increased sorting against long and medium length feed particles. This increase in sorting was greater in 0900-fed cows than in 2100-fed cows. Key words: Time of feeding, dairy cows, milk production, sorting

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Milk permeate as a dietary supplement for lactating dairy cows

Australian Journal of Experimental Agriculture ◽

10.1071/ea9900807 ◽

1990 ◽

Vol 30 (6) ◽

pp. 807

Author(s):

RT Cowan ◽

PC Upton ◽

A Reid

Keyword(s):

Dairy Cows ◽

Dietary Supplement ◽

Milk Fat ◽

Dry Matter ◽

Dry Matter Intake ◽

Fat Percentage ◽

Lactating Dairy Cows ◽

Ad Libitum ◽

Milk Permeate ◽

Sorghum Grain

Milk permeate was evaluated as a supplement to replace part of the concentrate or roughage in the diet of lactating dairy cows. The basal d i e t was 6 kg cracked sorghum grain and 6 kg ryegrass dry matter, and permeate was offered ad libitum in place of either 3 kg of sorghum or 3 kg of ryegrass. Intake of permeate stabilised at 30 kg/cow.day (1.7 kg DM) after 6 weeks, with considerable variation among replicate groups. Milk fat percentage was increased from 3.8 to 4.5% (P<0.05) when permeate replaced grain in the diet. Where permeate replaced pasture there was apparently large variation among cows in permeate intake, and this was associated with large variation in the fat and protein contents of the milk. Milk yield (volume) was reduced in proportion to the reduction in total dry matter intake (r = -0.99). With high intakes of permeate, the C18:0 acids in milk fat were reduced and the C16:0 acids increased. It was concluded that permeate could replace about 1.7 kg grain in the diet and that, at this level, there would be advantages in milk fat percentage.

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Effects of replacing extracted soybean meal with rapeseed cake in corn grass silage-based diet for dairy cows

Journal of Dairy Research ◽

10.1017/s0022029915000060 ◽

2015 ◽

Vol 82 (2) ◽

pp. 161-168 ◽

Cited By ~ 5

Author(s):

Jarosława Rutkowska ◽

Małgorzata Białek ◽

Emilia Bagnicka ◽

Justyna Jarczak ◽

Krzysztof Tambor ◽

...

Keyword(s):

Dairy Cows ◽

Soybean Meal ◽

Milk Fat ◽

Saturated Fatty Acids ◽

Health Condition ◽

Atherogenic Index ◽

Partial Replacement ◽

Control Group ◽

Fat Percentage ◽

Rapeseed Cake

The aim of the study was to assess the effects of partial replacement of soybean meal with a protein-equivalent amount of rapeseed cake in the diet on milking parameters and fatty acid (FA) composition of milk in dairy cows. Two groups of Holstein-Friesian cows, 8 each, consisting of randomised blocks were studied: a control group (C) was given a traditional high-protein supplement (extracted soybean meal) and the experimental group (E), had part of extracted soybean meal replaced with rapeseed cake. Dry matter intake and milk yield in both groups were not affected by the diet but milk fat percentage and yield were decreased in both groups. Rapeseed cake had no effect on milk acidity or on protein (including casein) and lactose contents. A lower concentration of urea in milk in E group indicated a proper ratio of protein to energy in the fodder. Health condition of mammary gland and indicators of metabolic profile were not affected by rapeseed cake supplementation. In E group, the share of atherogenic saturated fatty acids (FA) was reduced after 11 weeks: palmitic, by 26% and myristic, by 22%; moreover, as compared with control cows, the content of monounsaturated FA in milk increased by 44% after 3 weeks and by 68% after 11 weeks, t-18:1 and c-9 t-11 isomer of CLA increased about 2·5-fold after 11 weeks. In E group, the atherogenic index (AI) was significantly (P < 0·001) lower than in C (by 54% on average) and the decrease with time was considerable (by 29%, P < 0·001). Contents of odd- and branched- chain FA in milk were not significantly affected thus reflecting proper rumen function. Partial replacement of soybean meal with rapeseed cake in the diet of cows may improve both milking indices and FA profile of milk.

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Effects of Monensin and Dietary Soybean Oil on Milk Fat Percentage and Milk Fatty Acid Profile in Lactating Dairy Cows

Journal of Dairy Science ◽

10.3168/jds.2007-0232 ◽

2008 ◽

Vol 91 (3) ◽

pp. 1166-1174 ◽

Cited By ~ 49

Author(s):

O. AlZahal ◽

N.E. Odongo ◽

T. Mutsvangwa ◽

M.M. Or-Rashid ◽

T.F. Duffield ◽

...

Keyword(s):

Fatty Acid ◽

Soybean Oil ◽

Dairy Cows ◽

Fatty Acid Profile ◽

Milk Fat ◽

Milk Fatty Acid ◽

Fat Percentage ◽

Lactating Dairy Cows

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Production response in dairy cows milked two or three times a day: A meta-analysis

Veterinaria México OA ◽

10.22201/fmvz.24486760e.2020.2.562 ◽

2020 ◽

Vol 7 (2) ◽

Author(s):

Juan Isidro Sanchez-Duarte ◽

Alvaro Garcia ◽

Karla Rodríguez-Hernández ◽

David G. Reta-Sánchez ◽

Homero Salinas-Gonzalez ◽

...

Keyword(s):

Dairy Cows ◽

Milk Production ◽

Milk Fat ◽

Dry Matter ◽

Milk Protein ◽

Meta Analysis ◽

Milk Composition ◽

Fat Percentage ◽

Milking Frequency ◽

Production Response

The objective was to evaluate the effects of two (2×) vs three (3×) times per day milking on milk production and milk composition in dairy cows. Fourteen scientific papers, containing production data from 16 trials, where dairy cows were milked 2× or 3×, were analysed using meta-analysis with fixed and random-effects with the R statistical program. The degree of heterogeneity and publication bias were measured with the I2 statistic and Begg’s test, respectively. In addition, the meta-regression analysis explored other sources of heterogeneity for the response. The estimated effect size of 2× and 3× milkings was calculated for dry matter intake (DMI), milk production, and milk composition. Dry matter intake, milk production, and milk fat and protein yields showed substantial heterogeneity (I2>50%). Whereas milk fat-percentage had moderate heterogeneity (I2<50%), and milk protein had no (I2=0%)heterogeneity. The year of publication, trial duration, and cattle breed did not influence production response parameters to milking frequency. We found no evidence of publication bias for the parameters evaluated (Begg’s test; P>.05). Cows milked 2× produced less milk (2.23 kg/d), less milk fat (0.06kg/d), and less milk protein (0.05 kg/d). In contrast, the fat percentage was lower (0.07 units) in 3×, compared with 2× milking frequency. There was no effect of milking frequency on DMI and milk protein percentage. In conclusion, milk production and milk fat and protein yields improves as milking frequency increase from 2× to 3× daily, without affecting DMI. The implementation of 3× milking frequency must consider dairy cow management, labor, and milking parlour infrastructure, particular to each dairy farm.

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