Effect of Using Faba Bean and/or Italian Ryegrass in Total Mixed Rations to Dairy Cows.

The livestock sector must find solutions to reduce the feeding costs and meet the challenge for a more sustainable production system in line with the European Green Deal requirements. The aim of this study was to evaluate the effect of including legume silage on voluntary intake in dairy cows, milk production, and composition. Three total mixed rations (TMR) based on faba bean (FB), Italian ryegrass (IR), or faba bean-Italian ryegrass intercrop (FBIR, 60:40) silages were used in feeding trials of dairy cows during two consecutive years. Nine Friesian cows were randomly allocated in three groups, following a 3 × 3 Latin square design with three diets for three periods. TMR were offered ad libitum in addition to eighteen hours of grazing daily and extra concentrate during milking. No differences were observed in dry matter intake. Diets did not affect milk production or composition, except for urea content, with a higher urea excretion in FB diet. Fatty acid profile was different in milk from cows feeding FB, with a significantly lower content of saturated fatty acids and a higher content of conjugated linoleic acid than milk produced with FBIR and IR diets.

The Dairy Cow Slurry Composition Used as Organic Fertilizer Is Influenced by the Level and Origin of the Dietary Protein.

Less than 30% of dairy cattle's nitrogen ingested is retained in milk. Therefore, large amounts of nitrogen can be excreted in manure and urine with a potential environmental impact. In addition, some legume forages can be more susceptible to proteolysis during the silage process than grasses, and dairy cows fed these legume silages would excrete a larger quantity of nitrogen in slurry. The objectives of this work were to evaluate the amount of nitrogen excretion in dairy cows fed different protein levels and legume silages with a view to improve the slurry quality as a co-product that can be used as fertilizer. Two double 3 × 3 Latin square trials were carried out in order to study three different protein levels (high, medium, and low) and three different silages (grass, faba bean, and field pea). Dry matter intake, milk production, and composition were not affected by treatments. The excretion of ammonia-N in the urine was almost four times lower in the diet with the lowest protein level. The ammonia-N in the urine was twice as high with the pea silage than faba bean and grass silages. In conclusion, the diet containing 13% of protein meets the protein requirement for lactating cows producing 31 kg daily, with low nitrogen excretion in the urine, and the main pathway for the excretion of surplus nitrogen from legume silages is through urine and the metabolization of pea silage protein goes toward ammonia-N.

The Mode of Grass Supply to Dairy Cows Impacts on Fatty Acid and Antioxidant Profile of Milk.

The optimization of milk production includes a rational use of forages, respect for the environment and offers the best quality to consumers. Milk production based on grass and forages produces healthier milk and it is widely spread throughout the Atlantic arc to maximize milk yield per hectare. However, the mode of offering the grass can have a major influence on milk composition. The aim of this study was to evaluate the effect of grass supply mode (grazing, zero-grazing or ensiling) on dairy cows' performance, with particular reference to fatty acids and fat-soluble antioxidants concentration. A three by three Latin square experiment was performed with 18 dairy cows. Experimental treatments consisted of exclusive feeding with grass silage and zero-grazing, both offered ad libitum indoors, or grazing for 24 h. The results showed that grazing cows had a higher dry matter intake and greater milk yield than cows feeding on grass silage and zero-grazing, as well as higher concentrations of protein, lactose, nonfat-solids and urea in milk than housed cows. Milk fat from grazing cows had a higher proportion of unsaturated fatty acids than from cows feeding on grass silage and zero-grazing, with significant differences in the proportion of vaccenic and rumenic acids. The 18:1 trans-11 to 18:1 trans-10 ratio is proposed as biomarker to identify the milk produced from the management system of grazing cattle. Milk from grazing cows had a greater proportion of lutein than cows eating grass silage, with the zero-grazing system having intermediate values. In conclusion, the mode of grass supply affects fatty acid and antioxidant profiles of milk.

Capacity of milk composition to identify the feeding system used to feed dairy cows.

This Research Paper addresses the hypothesis that is possible to identify the type of feed used for dairy cows by means of the analysis of milk composition and the fatty acid profile of milk fat. Sixteen dairy farms were monitored during 1 year with quarterly visits between summer 2014 and spring 2015. Rations varied throughout the year due to annual dynamic change of forage production, forage rotation, variation of nutrient requirements according to physiological state of the animal, etc. The ingredients of the rations were analysed by cluster identifying five feeding systems based on the main ingredient of the diet: grazing, maize silage, grass silage, dry forage and concentrate. Milk composition could explain up to 91·3% of the total variability among feeding systems, while fatty acid profile could explain only up to 61·2% of total variability. However, when the sum of types of fatty acids and their ratios are taken, up to 93·5% of total variability could be explained. The maize silage system had the greatest milk yield, protein, solid non-fat and urea proportions, as well as the highest proportion of saturated fatty acid and lowest concentration of trans11 18 : 1, cis9 18 : 1 and 18 : 3 n3. Principal component analysis distinguishes the maize silage system from other feeding systems, both from milk composition and milk fatty acid profile. Concentrate system overlapped partially with the grazing, grass silage and dry forage systems. The latter systems had the highest concentrations of cis9 18 : 1, trans11 18 : 1 and 18 : 3, but there was no clear differentiation among them.

Handheld NIRS sensors for routine compound feed quality control: Real time analysis and field monitoring.

Significant advances achieved in different sensor technologies and computer processing data have made possible to respond the needs of livestock sector, providing precise and rapid information on feed composition, being an alternative to real time quality control on compound feed the use of handheld NIRS sensors. This work aimed to evaluate two hand-held portable NIR spectrophotometers for on-site and real time analysis of nutritive parameters in raw compound feed: Phazir 1624 Polychromix Inc (PhIR) and MicroNIRTM 1700 by JDSU (MICRO). For computing data, different combinations of pre-treatments and multivariate statistical methods have been assayed to extract the valuable information of spectra data and to develop appropriate calibrations. The calibration models displayed greatest predictive capacity for Crude Protein (CP), Crude Fiber (CF) and Starch (STCH) and the determination coefficients of cross validation were 0.90-0.88 for CP, 0.85-0.91 for CF, 0.89-0.88 and 0.89-0.91 for STCH using PhIR and MICRO instruments respectively. Dry Matter showed the lowest determination coefficients of cross validation 0.67-0.73. Accuracy achieved 99-101% for both NIRS instruments and no differences were found when applying tstudent-test comparing reference and predicted data. Results obtained with both instruments were compared by using standard deviation and not significant differences were observed at the 5% level. Results so far have demonstrated the potential of these handheld NIRS instruments proposed here to estimate the individual compound feeds composition changes at farms level instantly, time avoiding the disadvantage of moving the samples to the lab.

Subclinical ketosis on dairy cows in transition period in farms with contrasting butyric acid contents in silages.

This study examines the relationship between subclinical ketosis (SCK) in dairy cows and the butyric acid content of the silage used in their feeding. Twenty commercial farms were monitored over a period of 12 months. The feed at each farm and the silages used in its ration were sampled monthly for proximal analysis and for volatile fatty acid analysis. A total of 2857 urine samples were taken from 1112 cows to examine the ketonuria from about 30 days prepartum to 100 postpartum. Wide variation was recorded in the quality of silages used in the preparation of diets. Approximately 80% of the urine samples analyzed had no detectable ketone bodies, 16% returned values indicative of slight SCK, and the remainder, 4%, showed symptoms of ketosis. Most of the cases of hyperkenuria were associated with the butyric acid content of the silage used (r2=0.56; P<0.05). As the metabolizable energy content of the feed was similar, no relationship was observed between the proportion of cows with SCK and the energy content of the feed. In our study, the probability of dairy cows suffering SCK is higher when they are eating feed made from silage with a high butyric acid content (35.2 g/kg DM intake).

Effect of total mixed ration composition and daily grazing pattern on milk production, composition and fatty acids profile of dairy cows.

The possibilities of using high quality pastures in conjunction with total mixed ration (TMR) during the grazing season have been examined. An experiment with sixteen Holstein cows blocked and randomly assigned to four treatments in a factorial arrangement was conducted in order to evaluate the influence of grazing time of day (day or night) and type of silage (maize or Italian ryegrass) included in the TMR of dairy cows grazing 12 h daily on milk yield, composition and fatty acid profile. The silage type had no effect on the dry matter intake, milk yield and fat and protein proportions. However, cows grazing during the night ate more grass than cows grazing during the day (8·53 vs. 5·65 kg DM/d; P<0·05). No differences were seen between grazing-time with respect to milk production, fat and protein contents. However, the proportion of polyunsaturated fatty acid was higher in milk of dairy cows grazing at night-time than grazing at day-time, especially 18:2n-6 (2·37 vs. 2·12 g/100 g FA respectively, P<0·05) and 18:2cis9trans11 (2·08 vs. 1·74 g/100 g FA respectively, P<0·05).

Improving the fatty acid profile of dairy cow milk by combining grazing with feeding of total mixed ration.

Grazing cows could produce milk with a higher proportion of polyunsaturated fatty acids, which is beneficial to human health, compared with non-grazing cows, though grazing alone could compromise milk production. Under oceanic climate conditions, a study involving 15 dairy cows, fed total mixed ration (TMR) ad libitum in combination with different grazing times of 12 h (TMR12), 6 h (TMR06) and zero grazing time (TMR00) with the aim to evaluate different strategies on the fatty acids profile of milk and milk production. No differences were seen between the treatments with respect to milk yield (34.4+/-6.3 kg/d) or milk protein content (30.4+/-1.8 g/kg). The milk produced by the TMR12 cows had less total fat (36.2 vs. 38.2 g/kg) and saturated fatty acid (FA, 69.39 vs. 71.44 g/100 g FA) than that produced by the TMR00 cows. The concentration of vaccenic acid in the TMR06 and TMR12 milk was twice that of the TMR00 milk (4.22, 4.09 and 2.26 g/100 g FA respectively). Linear increases in conjugated linoleic (CLA) and linolenic acids were observed with increasing grazing time. Pasture was an important source of FA especially C18:3 for TMR06 and TMR12 cows. Under oceanic climatic conditions, the grazing of dairy cows as a complement to feeding with TMR can improve the FA profile of milk and increase its CLA content.