FEED CONVERSION

Abstract: This invention relates to techniques for improving the efficiency of feed conversion, growth and yield of meat from ruminant livestock. According to the broadest aspect of this invention there is provided a method of improving the growth rate and modifying the carcass quality of ruminant livestock, which comprises simultaneously feeding to the livestock, protected protein and protected lipid in ratios selected to meet protein and energy requirements favourable to the achievement of desired carcass characteristics.

Description: Feed Conversion Technical Field This invention relates to techniques for improving the efficiency of feed conversio growth and yield of meat from ruminant livestock. 5 Background Art The competitiveness of world beef markets is presenting producers with increasin pressures to achieve more efficient feed conversion by animals during the growing an fattening phases of their development. As dietary ingredients account for approximatel 70% of the costs associated with feedlotting of ruminants, small increases in the efficienc * o of feed conversion, growth rate and meat yield can have significant effects on the overa economic profitability of feedlot operations. At the same time, there are wider mark opportunities for producers who are able to manipulate carcass characteristics to me various national preferences. Hitherto, both the quantitative and qualitative aspects of beef production hav - = generally been approached by providing carefully regulated diets based on tradition feedstuff s, and by the adoption of controlled management practices, such as feedlotting It has, however, been recognised since the late 1960s that by feeding proteins or lipid which are protected from degradation in the rumen but available for absorption from th abomasum and lower digestive tract, it is possible to improve wool, meat or mil 20 production, and to modify carcass fat composition, in particular to increase th unsaturated fatty acid content of the fat. US Patent 3 507 662 concerns a feed supplement in which the protein content i primarily protected from rumen degradation by cross-linking with natural tannins. Th specification includes examples showing that the protein is indeed, protected but there i 25 no exemplification of body weight response. US Patent 3 541 204 concerns the encapsulation of biologically active substance such as amino acids, vitamins and drugs with hydrogenated fats to protect them fro rumen degradation. According to one example, finishing steers fed encapsulate methionine over a 10 week period exhibited weight gains which were of the order of 22 o better than those of animals on an unprotected control diet. In another example involvin growing/fattening steers, feeding encapsulated methionine over 30 days resulted in weigh gains approximately 14% better than those of animals on the control diet. Australian Patent 402 712 discloses a supplement in which the protein, by treatmen with an aldehyde, is rendered insoluble in the rumen but soluble in the abomasum. Th 5 invention is particularly directed to increasing wool growth in sheep, however, on example indicates that sheet fed the supplement were likely to experience a 6 to 8% bette body weight response than sheet fed an unsupplemented diet. Australian Patent 450 530 concerns a supplement in which the lipid component is encapsulated within aldehyde cross-linked protein to prevent reaction with rumen contents. The supplement is designed to permit modification (in particular to increase the unsaturation level) of ruminant meat and milk fat, and the feeding of high energy diets without digestive disturbance. The patent does not reveal that the supplement has any effect on growth rate. More recently, International Patent Application Publication WO91/05482 describes a ruminant supplement in which a protective encapsulating medium is cross-linked using the Maillard browning reaction. The examples demonstrate higher polyunsaturation in the fat of animals fed the supplement, but there is no reference to any effect on body weight. The prior art, then, has focussed on the gains from feeding a protected protein or from feeding protected lipid, but has not considered the consequences when an animal has access to both such materials. The present invention makes use of nutritional materials protected against rumen degradation, but offers the possibility of achieving food conversion significantly in excess of that previously reported. Additionally, the invention offers considerable scope for modifying carcass fat/protein ratios to meet market requirements. It is based on the discovery that simultaneous feeding of controlled amounts of protected protein and protected lipid results in increases in feed conversion, growth rate and carcass yield, which are greater than anything that might reasonably have been expected from past experiences of feeding such supplements independently, ie. there is a synergistic effect. Moreover the increases are of a magnitude which will almost certainly prove economically attractive to the producer. Brief Description of the Drawings Figure 1 shows the relationship between body weight and the weight of carcass protein and fat for beef cattle. The period A is the period of maximum muscular development, that is, when weight gain derives mainly from protein production - often called the "growing phase". Following what is called the "breakpoint" (B), there is a period (C) of even greater growth rate which can be attributed to increasing fat deposition, ie. a "fattening phase" . Disclosure of the invention According to the broadest aspect of this invention there is provided a method of improving the growth rate and modifying the carcass quality of ruminant livestock, which comprises simultaneously feeding to the livestock, protected protein and protected lipid in ratios selected to meet protein and energy requirements favourable to the achievement of desired carcass characteristics. According to another aspect of this invention there is provided a method of improving the growth rate and modifying the carcass quality of ruminant livestock, which comprises simultaneously feeding to the livestock, protected protein and protected lipid ratios varying from about 3: 1 to about 1: 1 during the growing phase to about 1 : 1 to abo 1:3 during the fattening phase. According to another aspect of this invention there is provided a method improving the growth rate and modifying the carcass quality of ruminant livestock, whi comprises simultaneously feeding to the livestock, protected protein and protected lipid ratios substantially the same as the carcass protein/fat ratios indicated in Figure 1. Definitions In this specification the term "simultaneous" is used to mean feeding within a peri of about 24 hours, ie. to realise the benefits of the invention it is not essential that t intake of protected protein and protected lipid takes place at the same time, rather it important that within a given 24 hour period the animals blood plasma is enriched wi both protein and lipid constituents by absorption from the abomasum or lower digesti tract. By "protected" we mean treated so as not to be fully exposed to the degradati action of the rumen environment, but available for absorption from the abomasum lower digestive tract. As will be apparent from discussion of the prior art earlier in th specification, a range of techniques have been developed for achieving such protectio Suitable techniques should allow accurate control of the amount of cross-linking th occurs between the protein feedstuffs and the aldehyde; this may be achieved by varyin the amount of aldehyde relative to the protein content and its amino acid composition, s that the protein is optimally "protected" from rumen degradation, but may be completel digested and absorbed from the small intestine. For the purposes of this invention t optimal degree of rumen protection lies in the range 50 to 70% , ie. 50 to 70% of t protein content of the supplement will pass undegraded through the rumen. Likewis dietary fats can be protected from ruminal metabolism by encapsulation in a matrix cross-linked proteins, and here the preferred window of protection ranges from 65% t 90% , especially 75% to 90% for fats derived from various sources; ie. 75% to 90% the fats will pass undegraded through the rumen. Best Modes of Carrying Out the Invention In performance of this invention it is likely to be most practical to feed animals supplement which combines a protected protein and a protected lipid. Typically the supplements will be fed at the rate of about 20% of the total feedlot ration, and the rati of protected protein to protected fat will vary depending upon the stage of growth an fattening. An economically viable source of both protein and lipid is likely to be oil see (eg. cotton, sunflower, canola), however it is also feasible to use proteins and fats derive from animal sources (eg. casein, tallow, lard) and this offers the flexibility to sele components of the protein-lipid mix according to the relative prices and availability of raw materials. Regardless of whether the adopted diet involves the supply of protected protein and protected lipid separately or in combination, the invention is not to be construed as requiring the continual, simultaneous feeding of protected protein and protected lipid throughout the growing and/or fattening phases. Clearly the benefits possible from practising this invention can be expected to be related to the continuity and period of feeding the protected materials, and to amounts fed, but other factors such as target markets and cattle specifications, eg. genotype, age, and physiological condition; the environmental situation (temperature, humidity), should also be taken into account when deciding on the feeding regime to be adopted. Thus, for the Australian markets, where there is a preference for lighter cattle, eg. having a body weight at slaughter of approximately 350kg to 400kg, the feeding of protected protein and protected lipid in the proportions of about 3:1 to about 1:1 for approximately 90 to 100 days would be recommended for optimum feed conversion, growth rate and carcass yield. Whereas in some of the Asian markets, eg. Japan, where meat containing a higher amount of fat and reproducible organoleptic characteristics (eg. texture, flavour) is preferred, the better procedure would be to change the proportion of protected protein to protected lipid from about 1: 1 to about 1:3 as the body weight of the animal increases from 400kg to 700kg during a 150 day feedlot period. Hence, the invention embodies a practical feeding strategy with considerable flexibility to satisfy the various phases of growth and fattening. Practice of this invention can be expected to offer economic benefits irrespective of the type of animal in question, however, a particular benefit will be observed with what might be called "high weight" steers, ie. steers above about 400kg. In a trial (see Example IV) with Hereford cross steers of average weight 470kg, the feeding of protected proteϊn/lipid supplements during the "fattening" phase resulted in about a 20% improvement in feed conversion, an increase in dressing percentage from 59.7 to 60.7, and, in the case of animals fed the high fat supplement (Group III), the fat content of the carcass was increased by about 10%. ("Dressing percentage" is the ratio of hot dressed weight, fat removed, to final live weight reduced by 4% to allow for shrinkage). The provision of protected feedstuffs in accordance with this invention, should not be seen as associated with any particular ration or dietary component, the invention does, however, offer unexpected additional benefits in certain circumstances. Thus (see Example V) the carcasses of animals fed an oat concentrate ration together with protected protein/lipid supplements during the growing period had 15% less fat content than similar animals fed a barley concentrate and protected supplements, but without any significant reduction in average live weight gain or feed conversion. This can be commercially important because oats can cost up to SAU40.00 per tonne less than barley, and also because of increasing market interest in low fat meat. Further, ionophores, such monensin, are widely used in the feedlot industry to improve feed conversion. We hav found (see Example VI) that the feeding of protected protein/lipid supplements i association with ionophores during the growing phase can effect dramatic (up to 40% 5 decreases in carcass fat content-again without any deleterious affect in carcass weight. The invention will now be described in greater detail by reference to specifi examples. Example 1: Preparation of Supplements (a) Protected Protein. :o Protected protein was prepared by spraying 37% (W/V) formaldehyde at the rate o 0.7g formaldehyde per lOOg crude protein into a rapid mixing device containing mille sunflower seed meal (38% crude protein). This material was then transferred to seale storage for 10 days to give a supplement 60% resistant to proteolysis in the rumen. (b) Protected Lipid. is Canola oilseed was coarsely comminuted in a hammer mill and mixed wit ethoxyquin (150ppm on an oil basis). This material was then mixed with water t produce a slurry and, after emulsification of the oil and protein in a colloid stone mill, th caustic soda was added to solubilise the oilseed protein. The protein constituents of th homogenised oil seed were cross-linked with 37% (w/v) formaldehyde at the rate of 2.7 20 formaldehyde per lOOg crude portion to form a gel which was then dried in a pneumati drier with an average hot air temperature of 300 °C to complete the reaction and produce protected lipid that was 85% resistant to metabolism in the rumen in vitro. Example II: Fifty Hereford cross steers, average weight of 290kg, were assigned to 5 groups o 25 10 and fed the following barley based concentrate rations for 133 days. The results of th trial are shown in the following table: SSM = Sunflower seed meal (NOT protected) PSM = Protected sunflower seed meal PCS = Protected canola oil seed 30 In groups IV and V the synergistic effects of feeding protected protein (15% o ration) and protected lipid (10 to 15% of ration) on warm carcass weight and dressin percent are clearly demonstrated. There was also a 9 to 10% improvement in feed conversion (feed gain), which was more pronounced in group IV, ie. where 15% protected protein and 10% protected lipid was fed. Example HI: Two hundred Hereford steers, average weight of 280kg, were assigned to two groups of 100 and received the following barley based concentrate ration. The results are shown in the followin table: SSM = Sunflower seed meal (NOT protected) PSM = Protected sunflower seed meal In this trial the synergistic effects of feeding protected protein (15 % of ration) and protected lipid (10% of ration) on daily weight gain and dressing percentage are demonstrated; there was a 10% increase in average daily gain and a highly significant increase (P < 0.05) in meat yield. Example IV: One hundred and sixty Hereford steers of average weight 47Qkg were assigned to three groups of 15 and fed a barley (55%)/Silage (8%) ration for 175 days. The results are shown in the following table: SSM = Sunflower seed meal (NOT protected) PSM = Protected sunflower seed meal PCS = Protected cotton seed (dehulled) The P8 site is over the eighth rib. Example V: One hundred and sixty Hereford steers of average weight 292kg were assigned to two groups of 80 and received either oats or barley concentrates rations supplemented with protected sunflower seed meal (PSM) 15%, and protected cotton seed lipid (PCS 10%. The results are shown in the followin table: PSM = Protected sunflower seed meal PCS = Protected cotton seed lipid supplement Example VI: Twenty Hereford cross steers of average weight 218kg were assigned to two group of 10 and received the following oat-based ration supplemented with protected cotton see (10%) with (+) or without (-) 320mg/d monensin. The results are shown in th following table: SSM = Sunflower seed meal PSM = Protected seed meal PCS = Protected cotton seed lipid supplement Industrial Applicability The present invention makes use of nutritional materials protected against rume degradation, but offers the possibility of achieving food conversion significantly in exces of that previously reported. Additionally, the invention offers considerable scope fo modifying carcass fat/protein ratios to meet market requirements. Practise of thi invention can be expected to offer economic benefits irrespective of the type of animal i question, however, a particular benefit will be observed with what might be called "hig weight" steers, ie. steers above about 400kg.

Claims: Feed Conversion Claims 1. A method of improving the growth rate and modifying the carcass quality of ruminant livestock, which comprises simultaneously (as hereinbefore defined) feeding to ε the livestock, protected (as hereinbefore defined) protein and protected (as hereinbefore defined) lipid in ratios selected to meet protein and energy requirements favourable to the achievement of desired carcass characteristics. 2. A method according to claim 1, wherein the source of both protein and lipid is oil seed (eg. cotton, sunflower, canola). o 3. A method according to claim 1 or claim 2, wherein the source of both protein and lipid is animal (eg. casein, tallow, lard). 4. A method according to any one of claims 1 to 3, wherein the degree of rumen protection (protein) lies in the range 50 to 70%. 5. A method according to any one of claims 1 to 4, wherein the degree of rumen s protection (dietary fats) ranges from 65 to 90%. 6. A method according to any one of claims 1 to 5, wherein the degree of rumen protection (dietary fats) ranges from 75 to 90%. 7. A method according to any one of claims 1 to 6, wherein the ratio of protected protein to protected fat is selected in accordance with the stage of growth and fattening of o the animals. 8. A method according to claim 7, wherein the protected protein and protected lipid are fed in the proportions of about 3: 1 to about 1: 1 for approximately 90 to 100 days for optimum feed conversion, growth rate and carcass yield. 9. A method according to claim 7, wherein the protected protein and protected 5 lipid are fed in the proportions of about 1: 1 to about 1:3 as the body weight of the animal increases from 400kg to 700kg during a 150 day feedlot period. 10. A method according to any one of claims 1 to 9, wherein the animals are fed a supplement which combines a protected protein and a protected lipid. 11. A method according to claim 10, wherein the supplement is fed at the rate of o about 20 % of the total feedlot ration 12. A method according to any one of claims 1 to 11, wherein the animals are fed an oat concentrate ration together with protected protein/Iipid supplements during the growing period. 13. A method according to any one of claims 1 to 12, wherein protected 5 proteϊn/lipid supplements are fed in association with ionophores during the growing phase. 14. A method of improving the growth rate and modifying the carcass quality of ruminant livestock, which comprises simultaneously feeding to the livestock, protected protein and protected lipid in ratios substantially the same as the carcass protein/fat rati indicated in Figure 1. 15. A method of improving the growth rate and modifying the carcass quality ruminant livestock, which comprises simultaneously feeding to the livestock, protecte . protein and protected, lipid in ratios varying from about 3: 1 to 1: 1 during the growin phase to 1: 1 to 1:3 during the fattening phase. 16. A synergistic composition for improving the growth rate and modifying th carcass quality of ruminant livestock, which comprises protected (as hereinbefore defined protein and protected (as hereinbefore defined) lipid in ratios selected to meet protein an • o energy requirements favourable to the achievement of desired carcass characteristics. 17. Meat and/or other products of ruminant livestock fed in accordance with th method of any one of claims 1 to 15.

Inventors: ASHES JOHN RICHARD, SCOTT TREVOR WILLIAM, ASHES, JOHN, RICHARD, SCOTT, TREVOR, WILLIAM
Applicants: ASHES JOHN RICHARD, COMMW SCIENT IND RES ORG, SCOTT TREVOR WILLIAM, COMMONWEALTH SCIENTIFIC AND INDUSTRIAL RESEARCH OR
Application year: 1993
Main classification: A23K1
IPC codes: A23K1