Relationship of residual feed intake with rumen fermentation and blood biochemical profile in growing buffalo calves
Abstract
The present study attempts to assess the relationship of residual feed intake (RFI) with rumen
fermentation and blood biochemical profile in growing buffalo calves. Twelve healthy buffalo calves of seven to
nine month of age were selected and fed with green fodder and concentrate mixture as per ICAR 2013 feeding
standards. Weighed amount of feed and fodder was offered and residue was also weighed next day, early in
morning. DM of feed and fodder offered and residue left was estimated on daily basis to assess DM intake. After
completion of feeding trial, RFI value for individual animals was calculated. Experimental animals were weighed
before starting the actual experiment and thereafter at fortnightly intervals. Using the data of fortnightly body
weights ADG was calculated. Body growth parameters viz. body length, height, heart girth and abdominal girth of
experimental animals were recorded in centimeters at the beginning, in the middle and at the end of experiment. A
digestion trial of 6 days was conducted at the end of the experiment to know the nutritive value of feed and fodder.
Representative samples of faeces, concentrate mixture, green and left over feed were taken daily and dried in hot
air oven for determining dry matter content. The six days dried samples of feaces, feed and fodder were pooled,
milled and analysed for proximate analysis according to AOAC (2005). A representative and homogenous sample
of rumen liquor was collected through a stomach tube from the rumen of animals of high and low RFI groups and
used for total nitrogen, ammonia nitrogen, total volatile fatty acids and individual volatile fatty acids estimation.
Blood samples were collected thrice, once at the beginning, in the middle and at the end of trial, from all the
animals for estimation of blood biochemical parameters in blood plasma. The results obtained regarding RFI
values for high and low RFI groups were 0.235±0.04and -0.235±0.06, respectively. Mean body weight, mean
metabolic body weight, average daily body weight gain and mean value of body growth parameters of the high
RFI and low RFI groups were non-significant. The DM consumption was lower in low RFI group compared to
high RFI group. Dry matter intake per 100 kg body weight (kg/100kg BW) and DMI per kg metabolic body weight
was significantly lower in low RFI group (P≤0.01). Total nitrogen and ammonia nitrogen were non-significant in
high and low RFI groups, while the TVFAs, acetic acid and butyric acid were negatively correlated with RFI
(P≤0.01). Blood glucose, total protein and IGF-1 were negatively but non-significant correlated with RFI. Plasma
albumin concentration was significantly positively correlated (r = 0.56) with RFI (P<0.01). BUN concentration
was non-significantly positively correlated (r = 0.35) with RFI. RFI was positively correlated with AST (r =0.44)
while negatively correlated (r = 0.35) with ALT.