Digestion and nitrogen conservation in cattle and buffaloes given rice straw with or without molasses

Abstract

S U M M A R YUsing [ 14 C]urea, the rates of urea synthesis in the body, excretion in the urine and degradation in the rumen and gut were compared in 20-month-old Kedah-Kelantan cattle and swamp buffaloes at the Universiti Pertanian Malaysia, Malaysia in 1987. The animals were fed rice straw or straw plus molasses.The buffaloes were heavier than the cattle and had higher straw and nitrogen intakes, although these intakes did not differ significantly when compared on the basis of metabolic liveweight (W°'").Rumen pH in the buffaloes was lower, whereas ammonia and total volatile fatty acid (VFA) concentrations were higher than in the cattle. Total VFA concentration was lower when the diet contained molasses. Rumen bicarbonate kinetics did not differ significantly between species or diets.There were no significant differences between species in plasma urea concentration, or urea synthesis rate per W 076 , or endogenous urea movement into the rumen per W 075 .The buffaloes consumed more water and discharged twice as much urine as the cattle, but nevertheless excreted less urea per W 0 ' 75 , and a larger fraction of their endogenously produced urea entered the gut. Movement of urea into the rumen per W 075 was lower when the diet contained molasses. I N T R O D U C T I O NComparisons of the rate of urea recycling to the rumen of cattle and buffaloes given the same low Microbial protein synthesised in the rumen from protein, straw-based diet suggest that buffaloes recycle ammonia and other nitrogenous compounds is the more urea to the digestive tract and to the rumen than source of most of the peptides and amino acids cattle Kennedy el al. 1987). The absorbed by the ruminant. When dietary protein latter workers also found that buffaloes maintained supply is below the requirement for liveweight higher concentrations of plasma urea and rumen maintenance, the recycling of endogenous urea pro-ammonia than cattle when given a straw-based diet, vides a continuing supply of ammonia-N to the An ability of buffaloes to utilize endogenous urea rumen. This promotes microbial fermentation, there-more efficiently than cattle may explain in part their by maintaining feed and digestible energy intake and apparent superiority in utilizing high-fibre, low-N microbial protein supply to the host and thus prolongs feed resources. the animal's survival.In the present study, urea synthesis rate in the body Endogenous urea can enter the rumen via saliva or and recycling of endogenous urea to the digestive by direct movement through the rumen wall (Houpt tract were determined by using [ 14 C]urea dilution 1959). The quantity of urea-N recycled to the rumen techniques in Kedah-Kelantan cattle (the indigenous appears to be related to plasma urea concentration, Zebu-derived cattle in Malaysia) and swamp buffaloes the amount of organic matter (OM) fermented in the (Bubalus bubalis) of the same age. The animals were rumen and the ammonia concentration in rumen fluid fed rice straw with or without molasses. The objective (Kennedy 1980). Other fac...

Comparison of feed intake, digestibility and fattening performance of Brahman grade cattle (Bos indicus) and crossbred water buffalo (Bubalus bubalis)

“…However, when intake was expressed as percent of the bodyweight or as per metabolic body size, the TDMI was not significantly different between species. This is in agreement with that reported by other workers (Abdullah et al . 1992) .…”

The comparative study digestion and metabolism of nitrogen and purine derivatives in male, Thai, Swamp buffalo and Thai, Brahman cattle

“…This may indicate that these other N sources cause N utilization in the rumen of Brahman cattle, and were either incorporated into microbial‐N or passed to the lower gut as a bypass protein. The mean BUN concentration, 16.5–39.0 mg/dL, observed in swamp buffaloes in this study was higher than the concentration of 5.1–5.7 mg/dL observed by Abdullah et al . (1992).…”

Comparison of fattening performance in Brahman grade cattle (Bos indicus) and crossbred water buffalo (Bubalus bubalis) fed on high roughage diet

“…Likewise, Moran (1983) in their experiment found that the buffalo had higher intake than cattle when fed elephant grass. In contrast, some workers found a similar DMI between cattle and buffalo (Abdullah et al . 1992; Lapitan et al .…”