Effect of By-pass Fat Supplementation on the Fat % in the Milk of Dairy Cows
Role of bypass fat in diet of the high producing crossbred cows is very crucial for enhancing the energy density of the diet. Dietary fat, that resist lipolysis and bio hydrogenation in rumen by rumen micro-organism, but gets digested in lower digestive track, is known as bypass fat. The technology of bypass fat protects the nutrient from degradation and bio hydrogenation in rumen with increase in the energy density of the diet enabling the animals to meet their energy and essential fatty acid requirement expressing their milk production potential to the fullest extent (Krishna Mohan and Reddy 2009). Additional fat fed as bypass fat does not interfere with rumen fermentation process, but supply more energy to animal for more milk synthesis after being digested in abomasums and small intestine with absorption from the small intestine this helps in increased unsaturated fatty acid in milk which can produce softer butter and safer milk for human consumption especially for heart patient .
In this scenario, along with improvement in indigenous germplasm through genetic approach, feeding and nutrition of high producing animals mainly buffalo gives a large amount of high-fat milk and at the same time in early lactation, the energy required for maintenance number of times exceeds the amount of energy available in diet, leads to negative energy balance, hence enforce utilization of body fat reserves to fascinate energy requirement, thus causes increase in the level of non-esterified fatty acids (NEFA) increases in plasma and leads to hepatic lipidosis. The negative energy balance affecting peak milk yield and overall lactation yield also cause delayed postpartum ovarian activity. In the early stage of lactation, body fat reserve helps to meet the energy requirement of high yielding milch animals. To solve this problem animal should be provided with either high level of cereal grains or raw edible oils given as such above 5-6 percent of total dry matter intake it may adversely affect fibre digestion, overfeed of grains may lead to rumen acidosis and bind divalent mineral ions. This may effect on feed intake of animal and there might be declined milk production, that’s the reason behind the concept of Bypass fat. In acidic ph, Bypass fat gets digested in the abomasum, without interfering with the fermentative digestion in the rumen. This form of fat supplementation termed as bypass fat, which can help in enhancing milk production and persistency of lactation.
BYPASS FAT: Most popular synonyms are Calcium salts of long-chain fatty acids, Rumen protected fat Bypass fat is the calcium salt of fatty acid, essentially dry fat that is generally mixed with animal feed mainly in dairy animal to improves, production of milk, metabolism, meat quality, reduces digestive problems, body condition by decreasing weight loss.
CHARACTERISTICS OF BYPASS FAT:
*Low solubility in the rumen.
· Less susceptible to biohydrogenation.
· Increase milk and fat yield in the early stage of lactation.
· Highly digestible energy supplement.
· Not degraded in the digestive tract (rumen) of animal, but gets digested in the lower alimentary tract.
TYPES OF BYPASS FAT:
2 types: Natural bypass fat and other is chemically prepared bypass fat.
A. NATURAL BYPASS FAT: Whole oil seeds with hard outer seed coat, which protects the internal fatty acids from lipolysis and bio-hydrogenation in the rumen (Ekeren et al., 1992). Oil seeds cakes commonly used in the ration of dairy animals are cotton, roasted soybeans, sun flower and canola. Soybean is having around 35% of bypass fat.
B. ARTIFICIALLY PREPARED BY PASS FAT
1) CRYSTALLINE OR PRILLED FATTY ACIDS: Crystalline or prilled fatty acids can be made by liquifying and spraying the saturated fatty acids under pressure into cooled atmosphere causes increase in melting point of the fatty acids which do not melt at ruminal temperature, resisting rumen hydrolysis and association with bacterial cells or feed particles thus by pass rumen degradation and digested in small intestine by lipase enzyme and make available energy for the productive processes such as lactation (Chalupa et al., 1986).
2) FORMALDEHYDE TREATED PROTEIN ENCAPSULATED FATTY ACIDS: Formaldehyde treated protein encapsulated fatty acids is also an affecting means of protecting dietary fat from rumen hydrolysis. Casein-formaldehyde coated fat has been used by the earlier workers. Oil seeds can be crushed and treated with formaldehyde (1.2 g per 100g protein) in plastic bags or silos and kept for about a week. The drawback of Formaldehyde treated protein encapsulated fatty acids is that in some cases it bypasses whole GIT.
3) FATTY ACYL AMIDE: Fatty acyl amide can be prepared and used as a source of bypass fat. Butylsoyamide is a fatty acyl amide consisting of an amide bond between soy fatty acids and a butylamine (Jenkins, 1998). Conversion of oleic acid to fatty acyl amide (oleamide) enhance the postruminal flow of oleic acid and monounsaturated fatty acids concentration of the milk, when fed to dairy cows (Lundy et al., 2004)
4) CALCIUM SALTS OF LONG CHAIN FATTY ACIDS: Calcium salts of long chain fatty acids (CaLCFA) are insoluble soaps produced by reaction of carboxyl group of long chain fatty acids (LCFA) and calcium salts (Ca++). Degree of insolubility of the Ca soaps depends upon the rumen pH and type of fatty acids. When rumen pH is more than 5.5, Ca-LCFA is inert in rumen. In acidic pH of the abomasum, fatty acids is dissociated from Ca-LCFA and then absorbed efficiently from small intestine. Among all forms of bypass fat, Ca-LCFA is relatively less degradable in rumen (Elmeddah et al., 1991), has highest intestinal digestibility and serve as an additional source of calcium (Naik et al., 2007).
MANUFACTURING PROCESS OF RUMEN PROTECTED FATS:
By pass fat can be manufactured based upon 2 types of mechanism
1. Based upon the melting point of fatty acid: Rumen protected fats with saturated fats are manufactured with saturated fatty acids. This fatty acid remains solid in environmental temperature but melt at the temperature of 50- 550C. So, this fat remains solid in rumen temperature (38-390C) and insoluble in rumen liquid but digested in small intestine.
Limitation- Relatively less digestible due to high proportion of saturated fatty acids.
2. Fatty acids of calcium salts: Based on acidity or ph level of rumen and small intestine. The main target of this method is to increase the digestibility of bypass fat in ruminant’s small intestine. This bypass fat is manufactured based on saponification of fatty acid. These are also known as calcium soaps. This compound is formed of saturated and unsaturated fatty acids joined to calcium ion to form salts. The calcium salts remain intact in neutral acidity of rumen (pH 6.2-6.8) & remain insoluble in rumen liquid but dissociate in acidic pH (pH 2-3) of abomasum. Fatty acids are soluble and absorbed in intestine more efficiently (95%).
REASON BEHIND THE FEEDING OF BYPASS FAT IN DAIRY ANIMALS: Pregnant dairy animals after parturition or In the early phase of lactation, is going through a stage where animal loses a huge amount of energy through milk. They start loosening body weight, due to the imbalance between energy intake and energy needed to satisfy the nutrient demand for milk production. Bypass fat helps to overcome this situation and helps to shift towards positive energy balance; this also helps in high reproductive performance, high milk production, and overall health and fulfils the nutrient requirement of high yielding animals, helps in to decrease the chances of metabolic disease like milk fever, ketosis and acidosis. Bypass fat can be a better choice of energy supplement to the dairy animal.
ADVANTAGES OF FEEDING BYPASS FAT: By pass fat is the most energy dense nutrient available that overcomes the deleterious effect of fats having a low melting point on fiber digestibility, feed intake and absorption of magnesium and calcium.
1) EFFECT ON REPRODUCTION: Supplementation of Ca-LCFA in the diet had a positive effect on reproductive performance of dairy cows, which is further dependent up on the specific fatty acids profile of the Ca salt. Feeding Ca-LCFA increases pregnancy rate and reduces open days (Sklan et al., 1991). Improved energy balance results in an earlier return to post-partum ovarian cycling. Increase linoleic acid may provide increase PGF2α and stimulate return to ovarian cycling and improve follicular recruitment; and increase in progesterone secretion either from improved energy balance or from altered lipoprotein composition from dietary fat improves fertility. Supplementation of bypass fat in KF cows in pre-partum period significantly (p<0.01) increased calf birth weight and decreased the cases of metritis & retention of fetal membrane. (Yadav 2014). The prilled fat feeding in KF resulted in earlier resumption of oestrous cyclicity, and improved conception rate. (Rajesh, 2013).
2) EFFECT ON BODY WEIGHT AND BODY CONDITION: Body condition score (BCS) provides the best estimate of body fat distribution than body weight (Ferguson et al., 1994). BSC of the cows was improved due to bypass fat feeding indicating reduction in weight loss in the first quarter and helped gaining substantially after 90 days of feeding.
3) EFFECT ON MILK COMPOSITION AND MILK YIELD: On supplementation of bypass fat in the diet of dairy animals, the milk yield is increased by 5.5-24.0% (Tyagi et al., 2009; Thakur and Shelke, 2010; Sirohi et al.,2010; Wadhwa et al., 2012). During the total lactation (early, mid and late) period, there was increase in the total USFA (32.01 vs 39.22), LCFA (75.61 vs 77.17) and MUFA (29.68 vs 33.53) and decrease in the total SFA (63.28 vs 54.02) as percentage of the total fatty acids of milk due to supplementation of bypass fat in the diet of dairy cows during (Tyagi et al., 2009). The SNF content of milk is either not altered (Naik et al., 2009).
4) EFFECT ON DRY MATTER INTAKE: DM intake (7.44-12.54 vs 7.65-13.60, kg/ d) of dairy animals was not altered (Mudgal et al., 2012) on supplementation of bypass fat. However, Tyagi et al. (2009) reported increase (3.16 vs 3.41; kg/100 kg BW/d) in DM intake in dairy animals fed bypass fat.
5) EFFECT ON DIGESTIBILITY OF NUTRIENTS: There was no effect of supplementation of bypass fat on the digestibility of DM, OM, CP, CF, NFE, TCHO, NDF and cellulose (Sirohi et al., 2010), which may be due to the non-interference and relatively stable nature of bypass fat.
SUPPLEMENTATION OF BYPASS FAT: Milch animals: 15-20 g/ kg milk production/ animal/ day. It can be supplemented to dairy cattle 15 days before to 150 days after parturition. Bypass fat used to mix with a concentrated mixture, can be given in two ways either single or as divided dose.
HOW DOES BYPASS FAT WORKS?
Bypass fat contains an unsaturated fat related to calcium particles, rather than a glycerol backbone. The association between fatty acid & calcium salt means the fat supplement with low solubility, less susceptible to bio-hydrogenation and remains 100% inert in the rumen. Although in the acidic pH of the abomasum, it dissolves and the fatty acid and calcium are set free for absorption.
EFFECT OF BYPASS FAT ON ECONOMICS:
Indigenous method of production of bypass fat is inexpensive; the total cost of production depends on the cost and availability of raw ingredients. Feeding of bypass fat to dairy animals generate additional profit of Rs. 34.50/- (Naik et al., 2009), Rs. 11.60/- (Gowda et al., 2013) and Rs 94.46 per cow per day (Yadav et al., 2015). Similarly, during early lactation bypass fat feeding of buffaloes yielding 8-9 kg of milk daily resulted in Rs. 26.61 more income per day (Parnerkar et al., 2010). In field conditions cost benefit ratio of 1.5 has been reported (Khan, 2015).
Effect of fat supplementation on milk composition
Metabolic status of dairy animals markedly influences the milk production and its composition . Milk fat is the most sensitive component of milk to any dietary changes. Bypass fat supplementation of lactating animals lead to either increased or decreased or not altered milk fat percentage. Naik stated that the addition of bypass fat in diet normally increases the total milk fat yield due to increase in the milk production. In another study conducted by Tyagi reported that due to supplementation of bypass fat in the diet of dairy cows increase in the total USFA (32.01 vs 39.22), LCFA (75.61 vs 77.17) and MUFA (29.68 vs 33.53) and decrease in the total SFA (63.28 vs 54.02) as percentage of the total fatty acids of milk. Reports by several researchers reveals that the SNF content of milk is not altered, whereas, Wadhwa found it increased; however, Naik stated that the total SNF yield was increased due to increase in milk production. Though Milk protein is more affected by feed than lactose, but Jenkins and McGuire consider it to be less affected than fat. Generally, supplementation of bypass fat (Ca-LCFA) has negative effect on the milk protein percentage , an overall effect of -0.12 percentage unit. No change in milk protein percentage was reported by many researchers whereas increase in protein percentage by Wadhwa . However, Naik considers the total milk protein yield was increased due to the increase in milk production. Nawaz supplemented fat in Nilliravi buffaloes @ 10, 20 and 30 g per liter of milk and found no significant change in milk protein and ash content. The lactose and total solid contents were least affected or not affected by the supplementation of bypass fat. McNamara stated that lactose concentration of milk gives only little information about energetic balances, as the content of lactose in milk of healthy dairy animal remains almost constant. Ramteke conducted an experiment on twenty-four pregnant buffaloes. In supplemented group buffaloes were given by pass fat @ 100 g/d for 30 days prepartum and 15g/kg milk yield per day for 120 days postpartum. They found significant increase in the yield (kg/head/d) of whole milk, fat, SNF, 6% FCM, SCM, ECM and fat percent in bypass fat supplemented group whereas no significant difference in the DMI of animals was found. Dietary supplementation of bypass fats and fatty-acids also influences the fatty acid profiling of milk. Generally feeding of Ca-LCFA in the ration of lactating cows lowers the proportions of short and medium chain saturated fatty acids (C6:0 to C16:0) of milk fat and it is due to decrease in de novo fatty acid synthesis in mammary gland and increase in proportions of LCFA (C18:1, C18:2, C18:3) due to increased uptake of preformed LCFA from blood . Rico supplemented ration with greater than 98% C18:0 at 2% of DM and reported that it does not reduced de novo synthesis of milk fatty acids, but very little of supplemental C18:0 was transferred to milk fat as compared to response to C16:0
Supplementation of bypass fat improves the energy balance of lactating dairy animals especially during the transition phase. Supplementation of bypass fat gives additional benefit due to increase in milk yield, fat yields, post-partum recovery of the body weight and body condition score and reproductive performance of the dairy animals. Supplementing bypass fat continues to be a practical means of sustaining energy intake in high-producing dairy animals. Bypass fat was proved to increase milk yield, milk quality, body parameters and reproductive efficiency of dairy animals without any negative impact on animal’s health. However, the economic success of using supplemental fat depends not only on proper selection of fat sources but also on quantity of fat to be fed and time of feeding. Use of bypass fat is age old practice but it is still researched and improved by the workers to make it more profitable and accessible to farmers.
Compiled & Shared by- This paper is a compilation of groupwork provided by the
Team, LITD (Livestock Institute of Training & Development)
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PREPARATION & FEEDING OF BYPASS FAT (Rumen Protected Fat) TO DAIRY ANIMALS
