Can concentrations of trans octadecenoic acids in milk fat be used to predict methane yields of dairy cows?

2017 ◽  
Vol 57 (7) ◽  
pp. 1465 ◽  
Author(s):  
P. J. Moate ◽  
S. R. O. Williams ◽  
M. H. Deighton ◽  
M. C. Hannah ◽  
J. L. Jacobs ◽  
...  

There is a need to develop simple, accurate methods for predicting methane emissions, yields and intensities of dairy cows. Several studies have focussed on the relationship between the concentrations of trans-10 plus trans-11 C18:1 fatty acids in milk fat and methane yield. The aim of the present study was to perform a meta-analysis to quantify relationships between the concentrations of various trans isomers of C18:1 in milk fat and methane emissions (g/day), methane yield (g/kg dry-matter intake) and methane intensity (g/kg energy-corrected milk yield). Data were from seven experiments encompassing 23 different diets and 220 observations of milk fatty acid concentrations and methane emissions. Univariate linear mixed-effects regression models were fitted to the data with the linear term as a fixed effect and with experiment and observation within experiment as random effects. Concentrations of trans-9, trans-10, trans-11 and trans-10 plus trans-11 isomers of C18:1 were poorly related to methane emissions, yields and intensities, with the best relationships being between trans-10 C18:1 and methane emissions (R2 = 0.356), trans-10 C18:1 and methane yield (R2 = 0.265) and trans-10 plus trans-11 C18:1 and methane intensity (R2 = 0.124). The data indicated that the relationships between trans-10 C18:1 and methane metrics were not linear, but were biphasic and better described by an exponential model. However, even exponential models poorly fitted the data. It is concluded that the concentrations of trans isomers of C18:1 have limited potential to accurately predict methane emissions, yields or intensities of dairy cows.

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 397-398
Author(s):  
Xiaoxia Dai ◽  
Kenneth Kalscheur ◽  
Pekka Huhtanen ◽  
Antonio Faciola

Abstract The effects of ruminal protozoa (RP) concentration on methane emissions from ruminants were evaluated in a meta-analysis using 67 publications reporting data from 85 in vivo experiments. Experiments included in the database reported methane emissions (g/kg DMI) and RP (log10 cells/mL) from the same group of animals. Quantitative data including diet chemical composition, ruminal fermentation, total tract digestibility, and milk production; and qualitative information including methane mitigation strategies, animal type, and methane measurement methods were also collected. The studies were conducted in dairy cows (51%), beef steers (32%) and small ruminants (32%). 70% of the studies reported a reduction in methane emissions. Supplemental lipids reduced methane emissions 95% of the time. The relationship between methane emissions and RP concentration was evaluated as a random coefficient model with the experiment as a random effect and weighted by the inverse pooled SEM squared, including the possibility of covariance between the slope and the intercept. A quadratic effect of RP concentration on methane emissions was detected: CH4= -28.8 + 12.2 × RP-0.64 × RP2. To detect potential interfering factors in the relationship, the influence of several qualitative and quantitative factors were separately tested. Acetate, butyrate, and isobutyrate molar proportions had positive relationships with methane emissions and influenced the relationship between RP concentration and methane emissions, where the presence of ruminal fermentation variables reduced the effects of RP concentration in methane emissions. Total tract digestibility of DM, OM, and CP had negative relationships while NDF digestibility had a positive relationship with methane emissions; however, they only changed the magnitude of intercept and slope of RP and RP2 for the relationship. For dairy cows, milk fat and protein concentrations had positive relationships and milk yield had a negative relationship with methane emissions and changed the magnitude of intercept and slope of RP and RP2 for the relationship.


2018 ◽  
Vol 58 (3) ◽  
pp. 489 ◽  
Author(s):  
K. Taylor ◽  
J. A. D. Ranga Niroshan Appuhamy ◽  
J. Dijkstra ◽  
E. Kebreab

The aim of this study was to develop and evaluate mathematical models that predict mineral excretion, particularly calcium (Ca), magnesium (Mg) and selenium (Se), from lactating dairy cows. Mineral excretion can be affected by several dietary factors. A deficiency in Ca or Mg application to pasture, among other factors, can contribute to grass tetany or wheat pasture poisoning in cows, whereas an excess can cause runoff into water supplies. Manure application with high Se concentration can also result in runoff, causing the bioaccumulation of selenium in aquatic ecosystems, wetland habitats and estuaries, leading to toxic levels in fish. A database composed of studies relating to mineral utilisation in lactating dairy cows conducted after and including the year 2000 was compiled. A meta-analysis was conducted with the aim of creating multiple empirical equations to predict Ca, Mg and Se excretion from lactating dairy cows. Calcium intake, feed Ca content, milk yield, milk protein content and acid detergent fibre content in diet were positively and linearly related to Ca excretion. Dietary crude protein content and milk fat content were negatively related to Ca excretion. Magnesium intake, feed Mg content and milk yield were positively and linearly related to Mg excretion. Selenium content of diet and dry matter intake were linearly and positively related to Se excretion. Two sets of models were developed using or excluding the intake variable and both sets of models were evaluated with independent data originating from commercial herd or individual animals. In general, intake measurements improved prediction when evaluated with independent datasets (root mean square prediction error = 8% to 19% vs 14% to 26% of the average observed value). There were substantial mean biases, particularly those evaluated with data from a commercial farm, perhaps due to inaccurate feed intake measurements. Although there was generally good agreement between predicted and observed mineral excretion, model development and evaluation would benefit from an expanded database.


2019 ◽  
Vol 102 (11) ◽  
pp. 10616-10631 ◽  
Author(s):  
A. Bougouin ◽  
J. A. D. Ranga Niroshan Appuhamy ◽  
A. Ferlay ◽  
E. Kebreab ◽  
C. Martin ◽  
...  

Author(s):  
A Gavelis ◽  
V. Þilaitis ◽  
A Juozaitis ◽  
V. Juozaitienë ◽  
G. Urbonavièius ◽  
...  

The aim of this study was to evaluate relationship between milk progesterone concentration (P4) and milk traits at the start of estrus time and 12h after start of the estrus in dairy cows. The 96 milk samples of 48 Lithuanian dairy cows without reproduction disorders and 90–100 days after calving were evaluated. Cows were classified into two groups based on milk yield per day: less than 30 kg (n=20) and e”30 kg (n=28). Data were categorized by milk fat and protein content at the start estrus and 12h after start of estrus to evaluate relationship between P4 and milk traits examined. P4 at estrus time in dairy cows was significantly positively correlated with milk yield (P less than 0.001), whereas it was negatively correlated with milk protein (P less than 0.05-P less than 0.01) and fat at 12h after start of estrus. Dairy cows with F/P from 1.0 to 1.5 had the lowest P4 in milk. Results of the pregnancy in dairy cows were related with lower P4 and milk yield level (P less than 0.001), higher milk fat (P less than 0.05) and milk protein content (P less than 0.001). These cows had 1.90 times lower prevalence of the signs of subclinical ketosis (P less than 0.05) at estrus time when compared with non-pregnant cows. As a result, it was clearly demonstrated that P4 in dairy cows can help to evaluate and improve the reproductive properties of cows.


2014 ◽  
Vol 54 (10) ◽  
pp. 1757 ◽  
Author(s):  
S. R. O. Williams ◽  
P. J. Moate ◽  
M. H. Deighton ◽  
M. C. Hannah ◽  
W. J. Wales

Methane (CH4) emissions from dairy cows are technically difficult and expensive to measure. Recently, some researchers have found correlations between the concentrations of specific fatty acids in milk fat and the CH4 emissions from cows that could obviate the need for direct measurement. In this research, data on individual cow CH4 emissions and concentration of caprylic acid (C8:0) and total C18 fatty acids in milk were collated from eight experiments involving 27 forage-based diets and 246 Holstein-Friesian dairy cows. Linear regressions between CH4 and both C8:0 and total C18 in milk were produced for published data and used to calculate 95% prediction regions for a new observation. The proportion of observed methane emissions from eight experiments that fell outside the 95% prediction region was 27.6% for the C8:0 model and 26.3% for the total C18 model. Neither model predicted CH4 emission well with Lin’s coefficient of concordance of less than 0.4 and the Nash–Sutcliffe efficiency coefficient of approximately zero for both the C8:0 and total C18 models. In addition, general linear model analysis showed significant differences between experiments in their intercepts (P < 0.001) and slopes (P < 0.001). It is concluded that the relationships tested cannot be used to accurately predict CH4 emissions when cows are fed a wide range of diets.


2009 ◽  
pp. 69-73
Author(s):  
Edit Mikó Józsefné Jónás ◽  
Imre Mucsi ◽  
István Komlósi

The authors examined the data of 2767 trial milkings andthe months Body Condition Scores of 479 Holstein dairy cows. The condition loss was significant between the 30-60th days. The improvement of BCS begins only after the 120th day. The change in the milk protein and milk fat content were close after the condition changing. In each period of the lactation the closeness of the relationship among the condition, the milk quantity and the milk composition were different. In the aspect of the milk quantity the most significant difference was between the 2.5 and 4 BCS cows (6.68 kg) in the last period of the lactation.


2020 ◽  
Vol 103 (3) ◽  
pp. 2373-2386 ◽  
Author(s):  
P.J. Moate ◽  
M.H. Deighton ◽  
J. Jacobs ◽  
B.E. Ribaux ◽  
G.L. Morris ◽  
...  

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Rodrigo N S Torres ◽  
João P A Bertoco ◽  
Maria C G de Arruda ◽  
Julia L Rodrigues ◽  
Larissa M Coelho ◽  
...  

Abstract The use of glycerin in diets for dairy cows initially emerged as an alternative for the prevention and control of ketosis. However, despite some controversy, there are still several studies associating glycerin with increases in daily milk yield, with possible changes in its constituents. Therefore, the objective of this study was to evaluate, using a meta-analysis approach, the effect of glycerin inclusion in dairy cow diets on milk fatty acid. Twenty-two peer-reviewed publications with 66 treatment means were included in data set. The effect of glycerin inclusion in diet (treatment) were evaluated using random-effect models to examine the weighted mean differences (WMD) between a control diet (without glycerin in the diet) and the treatment diet. Heterogeneity was explored by meta-regression and subgroup analysis performed for: genetic type; days in milk; experimental period; glycerin in diet; glycerin type and concentrate in diet. Inclusion of glycerin in the diet increased the digestibility of dry matter and protein, as well as ruminal propionate. It did not affect dry matter intake (P = 0.351) and milk yield (P = 0.730). The effect of glycerin inclusion on the milk fat yield is dependent on the genetic group, in which Holstein (WMD = −0.04 kg/d; P = 0.010) and Holstein-crossbreed (WMD = −0.10 kg/d; P &lt; 0.0001) cows produced less fat in milk compared to Jersey cows, when glycerin was included in the diets. Glycine inclusions of up to 100 g/kg in the diet of dairy cows did not negatively affect milk production and composition. However, inclusions above 150 g/kg of glycerin in the diet reduced the concentration of fat, and of unsaturated, monounsaturated, polyunsaturated fatty acids and conjugated linoleic acid (CLA C18: 2 cis-9 and trans-11) in milk. The results reported in our meta-analysis does not demonstrate the effectiveness of glycerin in improving the composition of milk and a group of fatty acids of importance for human health such as C18: 2 cis-9, trans-11 CLA.


Sign in / Sign up

Export Citation Format

Share Document