Ruminants beef cattle

McAllister MM, Gould DH, Raisbeck ME, Cummings BA and Loneragan GH (1997) Evaluation of ruminal sulfide concentrations and seasonal outbreaks of polioencephalomalacia in beef cattle in a feedlot. 1 Am Vet Med Assoc 211 1275-1279. 

Soybean products are excellent sources of protein and energy for beef cattle. Approximately 7.0% of the SBM utilized in the United States is fed to beef catde. This is a much smaller portion than the quantities utilized by swine and poultry (Fig. 18.1). The purpose of this section is to describe the reason for this relationship and how recent research may increase the use of SBM in beef cattle diets in the future. With over 40 million growing and finishing beef cattle produced in the United States each year, this is a huge potential market for soybean products. To understand why only 7% of the SBM consumed by livestock and poultry is fed to beef catde, one has to begin with a discussion of the digestive physiology of ruminants. 

Scollan et al. (2001) examined the effeets of different sources of dietary n-3 PUFA on the FA composition of muscle and adipose tissue in beef cattle. These authors found that the proportion of PA was decreased by the linseed diet in both neutral lipids and phospholipids of muscle. However, fish oil significantly increased the proportion of PA in neutral lipids, while Mandell et al. (1997) also foimd that fish meal feeding increased PA content, contrary to the lack of effect observed by Mills et al. (1992) on feeding fish meal and Ashes et al. (1992) who fed ruminally-protected fish oil. 

For ruminants, prediction is much more difficult, as many food variables may have to be taken into account. For approximate predictions of intake there are some rules of thumb. Thus, the daily dry matter intake of beef cattle is often assumed to be about 22 g/kg liveweight, whereas that of dairy cows is higher, at about 28 g/kg in early lactation and 32 g/kg at peak intake (see Figure 17.2). 

In many parts of the world, and in particular in the UK, barley forms the main concentrate in the diets of pigs and ruminants. In the barley beef system of cattle feeding, beef cattle are fattened on concentrate diets consisting of about 85 per cent bruised barley without the use of roughages. In this process the barley is usually... 

Calsamiglia S, Busquet M, Cardozo PW, CastUlejos L, Ferret A (2007) Invited review, essential oils as modifiers of rumen microhial fermentation. J Dairy Sci 90 2580-2595 Cardozo PW, Calsamiglia S, Ferret A, Kamel C (2004) Effects of natural plant extracts on ruminal protein degradation and fermentation profiles in continuous culture. J Anim Sci 82 3230-3236 Cardozo PW, Calsamiglia S, Ferret A, Kamel C (2005) Screening for the effects of natural plant extracts at different pH on in vitro rumen microbial fermentation of a high-concentrate diet for beef cattle. J Anim Sd 83 2572-2597... 

Oddy, V.H. and R.M. Herd, 2001. Potential mechanisms for variation in efficiency of feed utilization in ruminants. In Feed Efficiency in Beef Cattle Proceedings of the Feed Efficiency Workshop, Armidale, Australia. CRC for Cattle and Beef Quality, C. J. Hawkins Homestead, University of New England 30-34. 

Cappellozza, B.I., Cooke, R.F., Bohnert, D.W., Cherian, G., Carroll, J.A., 2012. Effects of camelina meal supplementation on ruminal forage degradability, performance, and physiological responses of beef cattle. J. Anim. Sci. 90, 4042-4054. 

The FDA first approved use of a polyether ionophore as a feed additive for cattle in 1975. Ionophores were first isolated from bacteria generally of the S treptomyces genus, but are produced commercially by bacterial fermentation (qv). Monensin [17090-79-8] and other ionophores are being fed to over 90% of feedlot catde grown for beef (53) to enhance efficiency of gain improvements of 5—10% are common. Ionophores also are used as anticoccidial dmgs in poultry production and have similar, but lesser, effects in ruminants (54). 

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