Original scientific paper

The effect of source and level of nitrogen supplementation on feed intake, microbial protein synthesis and nitrogen metabolism in mature heifers fed poor quality hay.

Paul Sebastian Mlay ; Department of Physiology, Biochemistry, Pharmacology and Toxicology, Sokoine University of Agriculture, Morogoro, Tanzania
Apolinaria Pereka ; Department of Physiology, Biochemistry, Pharmacology and Toxicology, Sokoine University of Agriculture, Morogoro, Tanzania
Sakurani Baltazary ; Department of Physiology, Biochemistry, Pharmacology and Toxicology, Sokoine University of Agriculture, Morogoro, Tanzania
Torben Hvelplund ; Department of Animal Nutrition and Physiology, Danish Institute of Agricultural Sciences, Research Centre Foulum, Tjele, Denmark
Martin Riis Weisbjerg ; Department of Animal Nutrition and Physiology, Danish Institute of Agricultural Sciences, Research Centre Foulum, Tjele, Denmark
Jørgen Madsen ; Department of Animal Science and Animal Health, The Royal Veterinary and Agricultural University, Copenhagen, Denmark

Abstract

The effect of nitrogen supplementation of poor quality hay on dry matter (DM) intake and digestibility, nitrogen balance and microbial protein was investigated using 5 ruminally fistulated mature heifers (1/2 Boran x 1/2 Friesian). The experimental set-up was 5x5 Latin square with 5 treatments and five periods, each of 28 days. In each period, 14 days were allotted to adaptation to treatments, a 7-day in vivo digestibility trial and total urine collection. Treatments were: poor quality hay only (HO) which was the control; hay with a low urea (32g/day) level (HLU); hay with a high urea (64g/day) level (HHU); hay with low soya bean meal (210g DM/day) (HLS), and hay with high (420g DM/day) soya bean meal (HHS). At a given level of supplementation, urea and soya bean meal was iso-nitrogenous. Hay was provided ad libitum with 10-15% refusal. Drinking water was provided ad libitum through automatic drinkers coupled to water flow meters. It was found that nitrogen supplementation led to significant increases in DM and OM intake and digestibility. Nitrogen retention and microbial protein synthesis were also significantly improved with nitrogen supplementation. Although soya bean meal showed a certain superiority in the improvement of these parameters, its cost would most likely hinder in its widespread use by smallholder farmers in Tanzania. Hence, it would be better to encourage the wide use of urea as a cheap source of nitrogen supplementation, especially for low- to medium-yielding animals in the smallholder dairy production system in Tanzania.

Keywords

low quality hay; intake; nitrogen supplementation; microbial protein

Hrčak ID:

67458

URI

https://hrcak.srce.hr/67458

Publication date:

20.4.2005.

Article data in other languages: croatian

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