Effect of Supplementation of Rumen Bypass Fat on Live Body Weight, Milk Yield, Milk Composition and Body Condition Score of Graded Murrah Buffaloes

During early lactation, the amount of energy required maintaining body tissues and milk production often exceeds the amount of energy available from the diet (Goff and Horst, 1997). Rising milk yield during early lactation presents a feeding problem in dairy cows as the peak milk yield occurs at 6 to 8 weeks postpartum, whereas the maximum feed intake lags behind peak milk yield by several weeks. In early lactation, to maintain high milk yield he dairy animals use their body reserves as an energy source to support high milk yield therefore, it is essential to store adequate amounts of nutrients in body tissues during late lactation. In early lactation, continuously rising milk yield increases energy deficit (Alapati et al., 2022). Energy demand is very high during an early stage of lactation, but intake does not commensurate with demand, thus affecting animal production potential (Sirohi et al., 2010). Hence, during early lactation, dairy animals are often forced to draw on body reserves to satisfy energy requirements, thereby substantially losing body weight, which adversely affects production, resulting in lower yield (Kim et al., 1993).
       
Including unprotected fat in the dairy ration above 3% of dry matter (DM) intake reduces DM and fibre digestibility (NRC, 2001). Besides, unprotected fat reduces rumen cellulolytic microbial activity (Ranjan et al., 2012).
       
Additional fat in the form of bypass fat supplies more energy to the animal for more milk synthesis after being digested in abomasums and small intestine with absorption from the small intestine without interfering with the rumen fermentation. Supplementation of bypass fat helps increase unsaturated fatty acids in milk, resulting in softer butter and safer milk for human consumption, especially for heart patients (Bobe et al., 2007, Garg et al., 2008).
       
It is stated that supplementing ration of lactating animals with bypass fat enhances energy intake in early lactation, reducing the harmful effect of acute negative energy balance on lactation (Tyagi et al., 2010). Therefore, undertook the present work to study the impact of supplementing rumen bypass fat on live body weight, body condition score, milk yield and composition in graded Murrah buffaloes during early lactation.
 

The trial was conducted at Livestock Farm Complex, College of Veterinary and Animal Sciences, Udgir dist. Latur (Maharashtra) in the year 2020. Ten graded Murrah buffaloes were selected for this study. All graded Murrah buffaloes were examined clinically for good health status. Optimum health score condition and good managemental care were confirmed in each animal before including it in the trial. The animals were subjected to identical housing and management conditions. The experimental animals were offered ad-libitum DHN 6 green fodder and 4 Kg of kadbi to each buffalo. The feed ingredients and fodder provided to them were unchanged during the trial period. The live body weight, milk composition and body condition score were recorded weekly and daily milk yield was recorded before and after rumen bypass fat supplementation to graded Murrah buffaloes. Rumen Bypass fat was offered @ 50 grams once a day/animal. Bypass fat was mixed in a concentrate mixture uniformly in the morning and fed individually to each animal. The trial was conducted for 84 days. Milk composition was analyzed on a Milkoscan milk analyzer. The live body weight was recorded on digital platform balance. Each buffalo’s weekly body condition score was recorded by looking at and handling the backbone, loin and rump areas for the amount of fat deposition. The data were analyzed by using paired T-test as per Snedecor and Cochran (1994).
       
The chemical composition of concentrate mixture is depicted in Table 1.


 
 

Average values of weekly body weight, body condition score, milk yield and milk composition were presented in Table 2. Weekly live body weight was found significantly (p<0.05) increased from the second week of supplementation and was increased up to the 10^th week of rumen bypass supplementation. The Average weekly live body weights ranged from 391.05±24.43 to 413.43±96 kg.


       
This finding is in agreement with Wadhwa et al., (2012); Puroshothaman et al. (2008) and Naik et al. (2009). 
       
The weekly body condition score, which ranged from 2.71±0.07 to 3.58±0.08 and was also found to be increased significantly (p<0.05) from the second week and a highly significant (p<0.05) increase in body condition score was observed up to the 11^th week of the study period. Similar observations were recorded by Ganjkhanlou et al., (2009) and Naik et al., (2009).
       
Highly significant (p<0.05) rise in milk yield during supplementation of rumen bypass fat was observed than the average daily milk yield before supplementation of rumen bypass fat to graded Murrah buffaloes. The average daily milk yield ranges from 4.15±0.43a to 5.35±0.42 liters/day. An increase in milk yield after supplementation of bypass fat was reported by Barley and Baghel (2009); Hundal et al., (2020) and Rohila et al., (2016), whereas Mudgal et al., (2012) reported no effect on milk yield of the crossbred cows on feeding bypass fat at late lactation.
       
Shelke et al. (2012) opined that improvement in whole milk yield is due to higher ME intake observed in this group due to fortifying the diet with rumen-protected fat.
       
Data from Table 2 indicated a non-significant difference between milk fat content before and after supplementation of rumen bypass fat up to the 7^th week of supplementation. A statistically significant (p<0.05) increase in milk fat percentage was observed from the 8^th week up to the 11^th week of supplementation. 
       
Rohila et al. (2016) and Sharda Kumari et al. (2018) reported increased milk fat content by supplementation bypass fat to Murrah buffaloes and crossbred cows. The probable reason for increased milk fat percentage might be the linear relationship between dietary, plasma and milk FA (Sarwar et al., 2003). Another reason for increased milk fat percentage was that increased dietary fat enhanced supply of fatty acids to the mammary gland from feed, which resulted in a lower proportion of denovo fat synthesis.
       
A significant (p<0.05) decrease in milk SNF (Solids not fat) was observed from the second week of rumen bypass fat supplementation upto the 11^th week of supplementation except 4^th and 5^th week of supplementation. Here, the decrease in milk SNF might be due to a significant increase in milk yield after bypass fat supplementation to buffaloes. Rohila et al., (2016) reported a non-significant difference in SNF content of buffalo milk before and after supplementation of bypass fat.
       
A significant to highly significant (p<0.05) decrease in milk density was recorded after the whole supplementation period of 84 days. The milk density percentage was decreased from 33.32±0.57 to 30.35±0.23. An increase in total solids in milk after supplementation of bypass fat to Murrah buffaloes was reported by Rohila et al., (2016).
       
Data on milk protein content indicated that the milk protein percentage was significantly (p<0.05) increased during the 1^st, 2^nd, 3^rd, 4^th, 7^th, 8^th and 9^th week of rumen bypass fat supplementation. The non-significant difference was observed in milk protein percentage on the 5^th, 6^th, 10^th and 11^th week of study before and after supplementation of rumen bypass fat to graded Murrah buffaloes. The milk protein percentage in this study ranged from 2.80±0.17 to 3.17±0.07. The improvement in milk protein content might be due to better utilization of feed proteins due to better energy to protein ratio after supplementation of bypass fat. The non-significant difference in milk protein content before and after supplementation of bypass fat to Murrah buffaloes was recorded by Rohila et al. (2016).
       
Milk fat, protein, yield and mean body condition scores increased linearly with increased fat saturation (Pantoja et al., 1996).
       
A non-significant difference (p<0.05) was observed in milk lactose content before and after supplementation of rumen bypass fat to graded Murrah buffaloes.
 
 

Based on observations found in this study, it was concluded that an increase in live body weight, body condition score and milk production was observed after supplementation of rumen bypass fat to lactating graded Murrah buffaloes, whereas non-significant to a significant increase in milk fat and milk protein was recorded. Supplementation of bypass fat leads to a decrease in milk SNF and milk density percentage. There was no effect of supplementation of rumen bypass fat found on milk lactose.
 

None.