Effect of niacin supplementation on rumen fermentation characteristics and nutrient flow at the duodenum in lactating dairy cows fed a diet with a negative rumen nitrogen balance

Context Several agro-industrial by-products such as oil palm meal could be useful as animal feeds in support of low cost of feed for livestock production. Aims This study investigated the effects of oil palm meal and urea pellet (PMUP) as a protein replacement for soybean meal (SBM) on feed intake, nutrient digestibility, rumen fluid characteristics, milk yield and milk composition in lactating dairy cows. Methods Five multiparous, early to mid-lactation, Holstein-Friesian crossbred dairy cows (75% Holstein-Friesian × 25% Thai Native Bos indicus) were randomly allocated in a 5 × 5 Latin square design to receive PMUP replacement for SBM at 0, 25, 50, 75 and 100% in concentrate. Key results The results show that roughage, total dry matter (DM), organic matter (OM) and acid detergent fibre (ADF) intakes in the cows fed with 25–75% PMUP were significantly higher than in the cows fed 100% PMUP (P < 0.05), whereas the ether extract (EE) intake of the cows receiving the PMUP was higher than that of the control (P < 0.05). Accordingly, the apparent digestibility, ruminal ammonia nitrogen (NH3-N) and total volatile fatty acid (VFA) of cows fed with PMUP replacement of SBM at 25–75% was higher than that in cows fed with 100% PMUP. In addition, milk yield and milk composition were not significantly different among treatments, whereas feed costs per kg milk yield was lowest in cow fed with 100% PMUP (P < 0.05). Conclusions Replacing SBM with PMUP up to 50–100% in concentrate could reduce costs of feed per kg milk yield, but lower feed intake, nutrient utilisation and rumen fermentation were observed in cow fed with 100% PMUP. The use of PMUP from 25–75% replacement of SBM had no significant effects on the feed intake, nutrient utilisation, rumen fermentation and milk production. Therefore, the level of PMUP replacement of SBM in concentrate for lactating dairy cow should not exceed 75%. Implications PMUP could be used as a protein replacement for SBM in concentrate for lactating dairy cows. These findings should be applied further in practical farm condition in order to increase livestock production efficiency.

Download Full-text

An examination of the effects of level of fish oil inclusion in the diet on rumen fermentation parameters in cattle

Proceedings of the British Society of Animal Science ◽

10.1017/s0308229600034395 ◽

1998 ◽

Vol 1998 ◽

pp. 226-226

Author(s):

C.S. Mayne ◽

T.W.J. Keady ◽

D A McConaghy

Keyword(s):

Fish Oil ◽

Dairy Cows ◽

European Community ◽

Milk Fat ◽

Rumen Fermentation ◽

Fat Content ◽

Lactating Dairy Cows ◽

Concurrent Study ◽

Liquid Milk ◽

Fermentation Parameters

The current milk quota regime within the European Community restricts both the volume and butterfat content of milk supplies from farms. Reduction in the butterfat concentration of milk enables an increase in liquid milk supplies, provided that the national butterfat base has been exceeded. In a concurrent study (Keady and Mayne, 1998) inclusion of fish oil in the diet of lactating dairy cows depressed butterfat content by up to 15 g/kg, consequently increasing the volume of milk which may be supplied in a quota situation by 0.27. The aim of the present study was to examine if the effects of fish oil inclusion on milk fat content were mediated via changes in rumen fermentation parameters.

Download Full-text