« back next »
Cattle Diets
Canola meal is widely used in cattle feeds. In dairy cattle feeds, it is considered to be a premium ingredient due to the high quality of its protein with respect to requirements for milk production.
Rumen Degradability
The rumen degradability of canola meal protein has been extensively studied. Table 1 provides a summary of the effective degradability of the dry matter and crude protein fractions of canola meal assuming a rumen turn-over rate of 5% per hour. Ha and Kennelly (1984) reported that the effective degradability of canola meal protein was 65.8%. Effective degradabilities of soybean meal and dehydrated alfalfa were 53.6 and 41.4%, respectively. Kendall et al. (1991) found that the effective degradability of canola meal averaged 51.5%. This compared to 59.1% for soybean meal. Cheng et al. (1993) reported that the effective degradability of canola meal was 62.5% with concentrate diets and 72 to 74% with hay or straw diets. Therefore, it is important when evaluating such results for ration formulation purposes to consider the type of diet into which the protein supplement is to be incorporated. Piepenbrink and Schingoethe (1998) reported a rumen degradability of canola meal of 53.1%.
Research at the University of Manitoba has focused on the digestibility of the amino acids present in canola meal. Kendall et al. (1991) noted that following 12 hours of rumen incubation, total tract digestibilities of amino acids present in canola meal approached 85% or greater. Considerable variation was noted between samples and between amino acids in the proportion degraded ruminally or absorbed postruminally. Boila and Ingalls (1992) reported that the amino acid profile of canola meal protein that bypasses the rumen was superior in valine, isoleucine, threonine, phenylalanine, serine, aspartate and alanine, relative to unincubated meal. The magnitude of the enrichment in the bypass fraction ranged from 14 to 33%.
The results, in combination with the data presented in Table 1, suggest that a sizable but variable fraction of the protein of canola meal bypasses the rumen. In light of the enriched amino acid content of the bypass fraction observed by Boila and Ingalls (1992), it would appear that canola meal provides an important contribution to both rumen microbial protein needs as well as to the digestible amino acids required for animal growth and lactation.
Dairy Cows
Many experiments have been conducted on the value of canola meal for dairy cows. Excellent and often improved milk production have resulted from the use of canola meal as a main protein source. Table 2 compares the effects on milk production of feeding canola meal to either soybean meal or cottonseed meal. Average milk yield in canola meal rations was 1.0 kg (4.0%) higher than the control ration.
Table 1 Summary of the effective rumen degradability of canola meal dry matter and protein fractions (rumen outflow rate 5% per hour)
|
Reference
|
Effective rumen degradability (%)
|
|
|
Dry matter
|
Crude protein
|
|
Ha and Kennelly (1984)
|
|
|
|
Trial 1
|
57.1
|
65.8
|
|
Trial 2
|
57.7
|
65.5
|
|
Kirkpatrick and Kennelly (1987)
|
|
|
|
Trial 1
|
63.0
|
63.2
|
|
Trial 2
|
64.2
|
72.0
|
|
Kendall et al. (1991)
|
53.5
|
51.5
|
|
Boila and Ingalls (1992)
|
60.6
|
67.3
|
|
Cheng et al. (1993)
|
|
|
|
Trial 1 (hay diet)
|
-
|
74.9
|
|
Trial 2 (straw diet)
|
-
|
72.3
|
|
Trial 3 (grain diet)
|
-
|
62.5
|
|
Piepenbrink and Schingoethe (1998)
|
65.1
|
53.1
|
Table 2 Milk production of cows fed canola meal compared to soybean meal or cottonseed meal
|
|
Milk yield (kg/day)
|
|
|
Control
|
Canola
|
|
Ingalls and Sharma (1975)
|
23.0
|
23.7
|
|
Fisher and Walsh (1976)
|
24.4
|
23.0
|
|
Laarveld and Christensen (1976)
|
24.9
|
26.4
|
|
Sharma et al. (1977)
|
20.7
|
20.9
|
|
Sharma et al. (1977)
|
21.5
|
21.8
|
|
Papas et al. (1978)
|
24.3
|
25.2
|
|
Papas et al. (1978)
|
23.9
|
24.6
|
|
Papas et al. (1979)
|
21.8
|
22.2
|
|
Laarveld et al. (1981)
|
26.4
|
27.7
|
|
Sanchez and Claypool (1983)
|
33.4
|
37.7
|
|
DePeters and Bath (1986)
|
39.8
|
41.4
|
|
Vincent and Hill (1988)
|
28.5
|
28.6
|
|
Vincent et al. (1990)
|
25.1
|
26.7
|
|
McLean and Laarveld (1991)
|
28.9
|
30.7
|
|
McLeod (1991)
|
17.2
|
16.9
|
|
Emmanuelson et al. (1993)
|
21.0
|
21.9
|
|
Dewhurst et al. (1999)
|
24.0
|
24.5
|
|
Dewhurst et al. (1999)
|
23.7
|
25.5
|
|
|
|
|
Average Milk Yield
|
25.1
|
26.1
|
Amino Acid Supply to the Dairy Cow
There is considerable interest in balancing dairy cattle diets to meet the amino acid requirements for maintenance, fetal growth and milk production. It is complicated because amino acids can be from two sources ·rumen microbial amino acids and rumen bypass feed ingredient amino acids. Once the amino acid requirements of the dairy cow and the amino acid contribution from rumen microbes are considered, then the first limiting dietary amino acid can be determined. There is some debate as to what the limiting dietary amino acids are in practical dairy cattle feeding (NRC, 2001, pp.73-74). Lysine has been suggested as first limiting in corn based diets and methionine has been suggested as first limiting in diets with low levels of corn and high levels of soybean meal. Type of forage used will also have an effect in that corn silage based diets would more likely to be limiting in lysine than alfalfa forage diets, which have higher lysine levels. In many dairy cattle diets, especially in Canada, little corn and soybean meal are used. In these diets, based on barley and alternative proteins to soybean meal, it has been suggested that histidine and the branched chain amino acids (leucine, isoleucine and valine) could be first limiting (NRC, 2001). Vanhatalo et al., (1999) have suggested that histidine is first limiting in dairy cattle diets where barley is used instead of corn. Schingoethe (1991) has also suggested that histidine can be first limiting in many practical diets.
The conclusions of the previous discussion are confirmed by the information in Table 3 in which the amino acid contents of rumen microbes, canola meal, soybean meal, corn gluten meal, cottonseed meal and sunflower meal are expressed as a percentage of the amino acid composition of milk protein. Canola meal is an excellent source of histidine, methionine, cystine and threonine. The abundance of these amino acids and the extent to which they supplement amino acids from other protein sources may, in part, explain the consistent milk yield response found when canola meal is included in dairy cow rations. Of all the protein sources listed in Table 3, canola meal has the best amino acid balance, as indicated by the relatively high level of its first limiting amino acid.
Another commonly used measure of protein quality for dairy cattle is ?ilk protein score·which relates the amino acid composition of protein sources compared to the amino acid composition of milk protein. The milk protein score of common ingredients ·as calculated by Schingoethe (1991) for a corn, corn silage and alfalfa based diet ·is shown in Figure 1. Canola meal has the highest score of all the supplemental protein sources (except fishmeal). Despite its excellent amino acid balance and milk production response, canola meal could be improved for dairy cattle by enabling more of the protein, especially the essential amino acids, to bypass the rumen. Various commercial processes, based on heat and chemical treatment, have been tried with canola meal, and there are several ?igh rumen bypass protein·products on the market.
Table 3 Ingredient and rumen microbe amino acid composition compared to milk protein (NRC, 2001)
(The first limiting amino acid in each protein source is highlighted.)
|
Amino acid as percent of milk protein
|
|
|
Milk % EAA
|
Rumen microbe*
|
Canola meal**
|
Soybean meal
|
Corn gluten meal
|
Cottonseed meal
|
Sunflower meal
|
|
Arginine
|
7.2
|
139
|
197
|
225
|
99
|
361
|
288
|
|
Histidine
|
5.5
|
73
|
138
|
111
|
85
|
120
|
113
|
|
Isoleucine
|
11.4
|
107
|
83
|
89
|
80
|
64
|
87
|
|
Leucine
|
19.5
|
81
|
82
|
88
|
190
|
71
|
133
|
|
Lysine
|
16.0
|
119
|
84
|
87
|
23
|
61
|
50
|
|
Methionine
|
5.5
|
84
|
95
|
58
|
95
|
67
|
102
|
|
Phenylalanine
|
10.0
|
104
|
103
|
116
|
141
|
125
|
110
|
|
Threonine
|
8.9
|
121
|
113
|
98
|
84
|
85
|
98
|
|
Tryptophan
|
3.0
|
90
|
115
|
93
|
40
|
93
|
97
|
|
Valine
|
13.0
|
85
|
88
|
78
|
79
|
77
|
90
|
*Assume 50/50 ratio of rumen bacteria and protozoa.
** Canola meal amino acid values from this publication, all others from NRC, 2001, p.72
Figure 1 Milk protein score of common feed ingredients for dairy cattle (Schingoethe, 1991)
Beef Cattle
Canola meal has gained widespread acceptance as a protein supplement for beef cattle. This acceptance is based in part on increasing producer experience with the product and from a number of research trials that demonstrate the value of canola meal for promoting the growth of young calves and growing and finishing cattle.
Canola Meal for Calves
Recently weaned calves have been shown to perform very effectively when canola meal is used as the protein supplement. Claypool et al. (1985) found that 45-day old Holstein calves gained at rates of 0.6 and 0.9 kg per day when offered a canola meal based starter ration during a seven-week preweaning and eight-week postweaning period, respectively. Performance of calves fed canola meal was similar to those fed cottonseed or soybean meal based starter rations. In British studies, no adverse influence of canola meal was observed on feed intake of 160 kg calves relative to soybean meal supplemented animals (Hill et al., 1990).
Canola Meal for Growing and Finishing Cattle
Most studies that have looked at canola meal supplementation of feedlot diets for cattle have not been iso-nitrogenous. The usual performance response observed with canola meal supplementation can often be attributed to the extra protein rather than the source of protein. Petit and Veira (1994) did show that canola meal resulted in increased ADG in crossbred steers (approx. 225 kg bodyweight) when protein levels were constant. Generally, there are no issues with regard to feeding canola meal to beef cattle.
Feeding Canola Seed and Oil
There is a considerable interest in feeding canola seed and canola oil to dairy cattle. The objectives are to increase the energy content of the diet and also, in the case of the seed, to provide a high quality dietary protein. Also, there is interest in increasing the level of unsaturated fatty acids in milk to make it ?ealthier·for humans. Heat and/or chemical treatment of the seed and oil are used to help both the protein and oil bypass the rumen (the oil is subject to bio-hydrogenation in the rumen). Chemical treatment with formaldehyde appears to have a greater effect than heat treatment of canola seed on increasing the level of unsaturated fatty acids in milk (Tymchuk et al., 1988).
Canola Meal Maximum Inclusion Levels
The recommended maximum inclusion levels for canola meal in cattle diets are listed in Table 4.
Table 4 Recommended maximum inclusion levels (%) of canola meal in cattle diets
|
Animal diet type
|
Maximum inclusion level
|
|
Calf
|
No limit |
|
Dairy
|
No limit
|
|
Beef feedlot
|
No limit
|
References
Boila, R.J. and J.R. Ingalls. 1992.
In situ rumen digestion and escape of dry matter, nitrogen and amino acids in canola meal. Can. J. Anim. Sci. 72:891-901.
Cheng, K.J., T.A. McAllister and L.M. Rode. 1993.
Use of acidulated fatty acids to increase the rumen undegradable protein value of canola meal. Tenth project report. Research on Canola Seed, Oil and Meal. Canola Council of Canada. Winnipeg. Canada.
Claypool, D.W., C.H. Hoffman, J.E. Oldfield and H.P. Adams. 1985.
Canola meal, cottonseed and soybean meals as protein supplements for calves. J. Dairy Sci. 68:67-70.
DePeters, E.J. and D.L. Bath. 1986.
Canola meal versus cottonseed meal as a protein supplement in dairy rations. J. Dairy Sci. 69:148-154.
Dewhurst, R.J., K. Aston, W.J. Fisher, R.T. Evans, M.S. Dhanoa and A.B. McAllan. 1999.
Comparison of energy and protein sources offered at low levels in grass-silage-based diets for dairy cows. Brit. Soc. Anim. Sci. 68:789-799.
Emanuelson, M., K.A. Ahllin and H. Wiktorsson. 1993.
Long-term feeding of rapeseed meal and full-fat rapeseed of double low cultivars to dairy cows. Livestock. Prodn. Sci. 33:199-214.
Fisher, L.J. and D.S. Walsh. 1976.
Substitution of rapeseed meal for soybean meal as a source of protein for lactating cows. Can. J. Anim. Sci. 56:233-242.
Ha, J.K. and J.J. Kennelly. 1984.
In situ dry matter and protein degradation of various protein sources in dairy cattle. Can. J. Anim. Sci. 64:443-452.
Hill, R. 1991.
Rapeseed meal in the diets of ruminants. Nutrition Abstracts and Reviews (Series B) 61(3).
Hill, R., I.C. Vincent and J. Thompson. 1990.
The effects on food intake in weaned calves of low glucosinolate rapeseed meal as the sole protein supplement. Anim. Prod. 50:586-587.
Ingalls, J.R. and H.R. Sharma. 1975.
Feeding of Bronowski, Span and commercial rapeseed meals with or without addition of molasses or flavor in rations of lactating cows. Can. J. Anim. Sci. 55:721-729.
Kendall, E.M., J.R. Ingalls and R.J. Boila. 1991.
Variability in the rumen degradability and post ruminal digestion of the dry matter, nitrogen and amino acids of canola meal. Can. J. Anim. Sci. 71:739-754.
Kirkpatrick, B.K. and J.J. Kennelly. 1987.
In situ degradability of protein and dry matter from single protein sources and from a total diet. J. Anim. Sci. 65:567-576.
Laarveld, B. and D.A. Christensen. 1976.
Rapeseed meal in complete feeds for dairy cows. J. Dairy Sci. 59:1929-1935.
Laarveld, B., R.P. Brockman and D.A. Christensen. 1981.
The effects of tower and midas rapeseed meals on milk production and concentrations of goitrogens and iodide in milk. Can. J. Anim. Sci. 61:131-139.
MacLeod, G.K. 1991.
Canola meal as a protein supplement in corn based dairy rations. Research on canola seed, oil and meal. Ninth project report. Canola Council of Canada. Winnipeg, Canada.
McClean, C. and B. Laarveld. 1991.
Effect of somatotropin and protein supplement on thyroid function of dairy cattle.
Can. J. Anim. Sci. 71:1053-1061. NRC. 2001.
Nutrient requirements of dairy cattle. 7th Rev. Ed., National Acad. Press, Washington, DC.
Papas, A., J.R. Ingalls and P. Cansfield. 1978.
Effects of Tower and 1821 rapeseed meals and Tower gums on milk yield, milk composition and blood parameters of lactating dairy cows. Can. J. Anim. Sci. 58:671-679.
Papas, A., J.R. Ingalls and L.D. Campbell. 1979.
Studies on the effects of rapeseed meal on thyroid status of cattle, glucosinolate and iodine content of milk and other parameters. J. Nutr. 109:1129-1139.
Petit, H.V. and D.M. Veira. 1994.
Effect of post-weaning protein supplementation of beef steers fed grass silage on performance during the finishing phase, and carcass quality. Can. J. Anim. Sci. 74:699-701.
Piepenbrink, M.S. and D.J. Schingoethe. 1998.
Ruminal degradation, amino acid composition and estimated intestinal digestibilities of four protein supplements. J. Dairy Sci. 81:454-461.
Sanchez, J.M. and D.W. Claypool. 1983.
Canola meal as a protein supplement in dairy rations. J. Dairy Sci. 66:80-85.
Schingoethe, D.J. 1991.
Protein quality, amino acid supplementation in dairy cattle explored. Feedstuffs. March 18, 1991. p. 11.
Sharma, H.R., J.R. Ingalls and J.A. McKirdy. 1977.
Effects of feeding a high level of Tower rapeseed meal in dairy rations on feed intake and milk production. Can. J. Anim. Sci. 57:653-662.
Tymchuk, S.M., G.R. Khorasani and J.J. Kennelly. 1998.
Effect of formaldehyde- and heat-treated oil seed on milk yield and milk composition. Can. J. Anim. Sci. 78:693-700.
Vanhatalo, A., P. Huhtanen, V. Toivonen and T. Varvikko. 1999.
Response of dairy cows fed grass silage diets to abomasal infusion of histidine alone or in combinations with methionine and lysine. J. Dairy Sci. 82:2674-2685.
Vincent, I.C. and R. Hill. 1988.
Low glucosinolate rapeseed meal as a protein source for milk production. Anim. Prod. 46:505.
Vincent, I.C., R. Hill and R.C. Campling. 1990.
A note on the use of rapeseed, sunflower and soyabean meals as protein sources in compound foods for milking cattle. Anim. Prod. 50:541-543.
« back next »