The evaluation of malt distillers grains ensiled with molassed sugar beet nuts as a feed for ruminants

McKendrick, Elizabeth Jan (1991) The evaluation of malt distillers grains ensiled with molassed sugar beet nuts as a feed for ruminants. MSc(R) thesis, University of Glasgow.

Abstract

The objective of the thesis was the evaluation of malt distillers grains (MDG) ensiled with molassed sugar beet nuts (MSBN) as a feed for ruminant livestock. The following subjects were reviewed: The voluntary feed intake of ruminants The use of sugar beet pulp as an absorbent Trends of agricultural practice The literature survey gave an account of animal performance results from relevant feeding experiments and considered the agricultural significance and the implications of the use of such a feed in ruminant production systems. Three experiments were carried out to evaluate MDG ensiled with MSBN as a feed for ruminant livestock. Experiment 1 assessed the use of MDG/MSBN as a replacer for proprietary concentrate in diets for dairy cows. Cows were fed either concentrate or MDG/MSBN at one of 3 levels - 3, 6 or 9 kgDM, plus grass silage ad-libitum. Cows offered 9 kgDM of MDG/MSBN were unable to consume all the feed, probably due to a bulk restricting factor. Proprietary concentrates were successfully replaced by MDG/MSBN up to the level of 5 kgDM. At this level of replacement milk yield was maintained, but milk fat content was reduced by 3.6 g kg-1. Experiment 2 evaluated a forage mix consisting of MDG/MSBN, chopped straw and minerals. Dairy cows were fed one of three forages - grass silage, MDG/MSBN/Straw/Minerals (MDG mix) or a 50:50 DM mix of the two already mentioned supplemented with 7 kg of proprietary concentrate. Cows fed MDG mix diets ate 4.5 kgDM more than silage fed cows and total DM intake results were high, especially on treatment MDG (DM intake - 19.3 kg). There was a mean increase in milk yield of 2.7 kg d-1 for the MDG treatments compared to the silage treatment. Milk fat content was similar for cows fed the silage and the silage/MDG diets, however cows fed the MDG mix diet had a reduced milk fat content of 3.1 g kg-1. The low milk fat content results produced by cows fed MDG diets may have arisen due to the effect of dietary fat. The fat supplied by MDG diets has a high proportion of long chain fatty acids and is highly unsaturated. Malt distillers grains contain high levels of this fat which may lead to a reduction in the mammary synthesis of milk fat. The final experiment considered the use of MDG/MSBN as the sole dietary constituent in a bull beef finishing programme. The performance of bulls fed this diet was compared to the performance of bulls fed a conventional silage/concentrate diet. Bulls fed MDG/MSBN finished approximately 3 weeks earlier than silage fed bulls. Liveweight gain was 1.56 and 1.35 kg d-1 for the MDG and silage diets respectively. Bulls fed the by-product diet consumed more DM than silage fed bulls. As a higher proportion of the energy from the MDG diet was in the form of fat, the energy was utilised with greater efficiency, generating a higher level of performance. The MDG/MSBN proved to be a flexible feedstuff. Its use was acceptable as a concentrate or forage for dairy cows, and also as the sole diet for bull beef livestock. In future years, conventional feedstuffs such as proprietary concentrate or grass silage may be replaced or supplemented by evaluated alternatives such as MDG/MSBN.

• Item Type: Thesis (MSc(R))
• Qualification Level: Masters
• Additional Information: Adviser: Dr. D. J. Roberts
• Keywords: Animal sciences.
• Colleges/Schools: College of Medical Veterinary and Life Sciences
• Supervisor's Name: Supervisor, not known
• Date of Award: 1991
• Depositing User: Enlighten Team
• Unique ID: glathesis:1991-73401
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 14 Jun 2019 08:56
• Last Modified: 22 Jul 2021 08:53
• URI: https://theses.gla.ac.uk/id/eprint/73401