The most significant objective in dairy farming is to produce high quality milk that also attains the highest financial standards and at the same time accomplish this by inflicting the least amount of damage to the cows’ health and reproductive systems. Under today’s feeding conditions, only 30% of the energy and protein consumed by the cow can pass on to the milk. 30% of energy is lost with feces, 3% with urine, 5% with gases and 25% is lost through the body in the form of heat. Different practices in terms of feeding may influence the fat, dry matter and protein ratio of the milk. Increasing the milk’s protein content is desired in particular with regards to human consumption.
Main principles in relation to the nourishment of the dairy cattle
The nourishment of the dairy cattle, which is a ruminant, can be considered primarily from two perspectives. One of these is feeding the rumen microbes and the other is feeding the cattle’s own tissues. Such a diet also contains important privileges.
- Feeding the rumen microbes
The microbes in the rumen may use ammonia, amino acids and peptides as nitrogenous substances. However, different types of microbes have different preferences. The microbes that can ferment the structural carbohydrates of the plant cells such as cellulose and hemi cellulose, use ammonia as their source of nitrogen and synthesize their own proteins from here. Even though the microbes that ferment the sugar, starch and pectin stored within plant feed substances and that do not carry out a structural duty, use ammonia as their source of nitrogen, they can reproduce more rapidly in those mediums where peptides and amino acids are present. Given these, in order to fulfill the abovementioned ammonia and amino acid requirements, 50% of the protein that will be consumed, should be dissoluble. Energy requirement of the microbes can only be fulfilled with carbohydrates and their fermented products. For this reason, the fats are not used and the excessive amount of fats accumulating also lead to an increase in the number of rumen microbes. Given this, if there is excess fat in the ration then there would occur a need for excessive protein that is not broken down within the rumen (by-pass).
- Feeding the cattle’s tissues
The nitrogenous substances that will be used during the formation and the growth of animal tissues as well as milk synthesis are only amino acids. The amino acids that will be used by the dairy cattle can be obtained as a result of digesting rumen microbes, or they can be attained through the digestion of the by-pass proteins that are not fermented. For milk production, if these resources cannot fulfill the needs, then a certain amount of amino acid that is stored in the body can be used. The majority of the cattle’s energy need is fulfilled by the volatile fatty acids (acetic, propionic, butyric) that are formed in the rumen. However, when these are not enough, the fats moved from the fat tissues in the body will compensate for the energy deficiency. In particular, the first thirty days after giving birth, if the cattle do not consume enough feed and since milk production gradually increases, the cattle will spend significant amount of fats from its body that will stand out. The days following this period and approximately within 200 days, the tissues spent have to be replaced. For this reason, the dairy cattle’s feeding should not include any insufficiencies. Another source of energy that can be used by the dairy cattle is the Lactation 100 Dairy Cattle Feed that is produced by Çamlı Yem. As it contains by-pass fats within its structure and the energy and protein it comprises, allows it to easily address the needs of highly productive dairy cattle.
Developments in ration preparation
Sometimes the rumen system may not be enough to address the needs of highly productive dairy cattle. As a consequence, fats, proteins and amino acids that may pass through the rumen without being broken down (by pass) are produced.
These kinds of substances pass directly on to the intestines and their digestion starts in the intestines and as a result they are not affected by the breakdowns within the rumen. It would be beneficial to examine these substances more closely.
The fatty acids that make up the fats have a different kind of effect on the rumen microbes. Even though stearic and palmitic acids, which are saturated fatty acids do not have an impact on rumen microbes, the unsaturated fatty acids can kill them. Moreover, the unsaturated fatty acids prevent their digestion by covering and shielding the feed particulates in the rumen. Therefore, while giving the by-pass fats to the cattle after coating them eliminates the negative impact, having them break down in the intestines provides an opportunity to benefit from the positive effects they may have.
We see that the fats contained within the dairy cattle’s ration come from 3 different sources. One of these is the fat coming from grains and grass and they make up 3% of the ration. The fats that are contained within the essence of oil seeds, as well as the fats and oils that directly enter the ration form the second source. The amount of fats that enter the ration this way should be around 2%. The unpreserved fat rate within the dry matter contained in the dairy cattle’s ration should not exceed 5%.
The third source of fat that might be included in the ration are the additives that are produced within the rumen as preserved fats that are close to any interaction. A highly productive dairy cattle that consumes around 20 kg of dry matter each day, consumes 1.4 kg of the fat that makes up 7% of the dry matter.
Proteins show significant variety depending on how they are broken down in the rumen and incur a considerable amount of loss. Those systems that consider these losses and the amount of protein that can escape the rumen (by-pass protein) have been developed. Additionally, preserved products that are made up of plant and animal proteins have been developed in order to increase the amount of by-pass proteins. These also pass through the rumen in order to address the needs of highly productive animals within the rumen.
Amino acids that the dairy cattle need are not always sufficiently met by the rumen microbes and the proteins that escape the rumen. For this reason, synthetic amino acids that can pass through the rumen without breaking down started to be produced. Among these, lysine and methionine have been subject to hydroxyl analogue treatment. Meanwhile, the products made up of the combination of fatty acids and amino acids are considered as addressing two different purposes.
Currently, it is common practice to consider the feeds’ carbohydrate content by dividing into two sections. These are denoted in two groups as those that contain fibers and those that do not contain fibers. Fibrous carbohydrates are made up of pectin, cellulose, hemi cellulose and lignin, whereas non-fibrous carbohydrates contain sugar and starch. Fibrous carbohydrates can be classified as “structural carbohydrates” as they form the walls of plant cells and non-fibrous ones can be categorized as “non-structural carbohydrates”. The carbohydrates that infiltrate and slip during the decomposition process that is carried out using the neutral detergent method make up the non-structural carbohydrates. The residues that are formed during the infiltration process are the structural carbohydrates.
The roughage is mostly made up of fibrous carbohydrates and these are necessary for the rumen to function properly and healthily. The fibrous carbohydrates contained within the structure of concentrate feeds do not contribute to the functioning of the rumen significantly. While there might be differences during the digestion of the fibrous carbohydrates within the rumen, the digestion of non-fibrous ones might also differ. For instance, the fibrous parts of clovers are digested more rapidly than the meadow grass. Among non-fibrous carbohydrates starch digestion may be listed as wheat, barley, oat, corn and sorghum according to their speed of digestion.
We see that different feed additives are used in order to keep the productivity rates high in dairy cattle and to eliminate possible metabolic malfunctions. Highly productive cattle need a ration application that has been intensively prepared and rich in non-fibrous carbohydrates in order to address their energy needs and such an application creates an acidosis formation that ranges between mild and medium strength.
In order to eliminate such a mild acidosis for the most part, sodium bicarbonate is added to the feeds in general. It is also common practice to use additives that prevent the ammonia that has been formed in the rumen from passing on to the liver.
As a result of this, the nitrogen coming from the ammonia are converted into by-pass proteins. In addition to this, probiotics are the primary alternative biotechnological products. These are used to regulate the microflora balance within the digestion channel, to prevent the pathogenic microorganisms from turning into harmful microorganisms and from reproducing, and they are used for feeding animals so that the advantages obtained from the feed can be increased.
The impact of feeding on the structure of the milk
The substances that are formed as a result of digestion influence milk production and the structure of the milk. The acetate, glucose, amino acids and long chain fatty acid levels inside the cattle’s stomach have an increasing effect on milk production. The percentage of fat in the milk increases with acetate, butyrate and long chain fatty acids while it decreases as the amount of propionate and glucose increase.
The amino acids, glucose and propionate have an increasing effect on the rate of protein in the milk. Long chain fatty acids decrease the amount of protein. According to this, since an increase in the amount of by-pass protein that the cattle’s ration contains will also increase the amount of amino acids, this will have a positive impact on the milk’s protein rate. However, this increase is limited and depends on the cattle’s genetic structure.
Daily feed consumption
Determining the amount of feed that will be consumed daily by the dairy cattle in the form of dry matter means expressing the feeds that contain different rates of water through invariant measures. The dry matter consumption of cattle differs depending on the cattle’s live weight, productivity level, the feed’s digestion rate or environmental factors.
If the digestion rates of the feed substances in the ration are too high or if the amount of nitrogenous substance that is burnt rapidly is in excess, then the dry matter consumption rate may drop. In the same way, if the water factor exceeds 50%, then the dry matter consumption rate may drop. Another way to increase the dry matter consumption in dairy cattle is to give the feeds that encompass the nutrients that they need daily, three times a day, to use the fans that will eliminate the stress caused by heat. These will not only increase the amount of feed consumption but they will also ameliorate the quality of the milk.