In “Nutrition Ecology of the Ruminant” (1982), Peter J. Van Soest introduced new nutrients that were subsequently used for the development of the Cornell Net Carbohydrate and Protein System (CNCPS®), and accurately described the ecological position of ruminants. This book is important to understand physiological differences among animals that are part of the same class (Mammalia), order (Ruminantia), and family (Bovidae). During the Neolithic (10.000 – 3.500 AC), humans started animal domestication. From the ancient Bos primigenius we have the modern bovines, from Capra aegagrus the goats, from the genus Ovis the current sheep, and from Bubalus antiquus our reared buffaloes. These different ruminant species eat different kinds of vegetation even when living in the same habitat, to reach the best feed availability with the least feed competition. Nowadays, the differences in the vegetation must be extremely clear to nutritionists that formulate diets for different ruminant species: they need different nutrients, in different concentrations, and with different granulometry or fiber length.
Figure 1 reports the ratio between the hypodontic index (HI, the ratio between the height of the third molar crown and its occlusal width) and the palate/face width ratio (RMW) of different herbivores species. Buffaloes have high HI and RMW (big molars and wide mouth), to quickly swallow a huge amount of grasses with different digestibility and to have a subsequent strong rumen chewing. Sheep and goats are more selective, with low HI and low RMW: this type of mouth facilitates the selection of the most tender plants, but also of the concentrates in the unifeed rations.
Another difference among these ruminant species is the ratio between pre-stomachs and intestine. Buffalo rumen is bigger and its intestine is shorter than the cow ones. On the contrary, goats have smaller rumen and longer intestine than bovines. Sheep are just in the middle between cows and goats. Buffalo conformation leads to long ruminal transit time with effective fiber fermentation and maximized production of metabolizable protein and volatile fatty acids.
Figure 1: HI and RMW ratio in different herbivorous species. From Nutritional Ecology of the Ruminant”, Peter J. Van Soest, 1982
To recap, the most important differences between buffalos and cows are:
- Better utilization of low-quality feed (Norton, 1979; Devendra, 1983; Moran, 1983);
- Higher feed rumen degradation (Infascelli, 1995);
- Different microbiota (Zaki el-dine, 1985), a higher concentration of cellulolytic bacteria Sadhana, 1992; Malakar, 1995) and protozoa (Franzolin, 2006);
- Higher rumen biomass and higher organic matter to produce the biomass;
- Slower rumen feed transit time;
- Better absorption of volatile fatty acids;
- Longer rumination time than ingestion time;
- Higher ammonia concentration in the rumen, probably due to a higher hepatic urea synthesis. This leads to better cellulose digestibility.
Cows and buffaloes’ nutritional approach must be different. The numerosity of these reared species influences scientific research and investments: buffaloes are studied typically in the Mediterranean area, South-America, India, and China. The University of Naples is one of the most important for buffaloes study, while the US is one of the most important research centers for bovines.
Fundamental principles behind dairy nutrition
The CNCPS® and the Nutrient Requirements of Dairy Cattle (NRC 2001) contain the theory behind nutritional requirements for maintenance, production, reproduction, growth, and body storages that are used by dairy cows. CNCPS® introduced mathematical regressions for each dietary component and calculates in a very specific way, through a series of interconnected equations, daily nutrient requirements, and especially the metabolizable energy (ME) and protein (MP). For example, to calculate the MP, the system calculates the growth rate of the main microbial species in the rumen related to the ingestion of different feeds. Then it extrapolates the amount of protein that is undegraded in the rumen.
To create a successful diet for dairy cows by CNCPS® it is necessary to know animal requirements, the exact composition of different feeds, and their rumen degradation and transit time. Genetic selection has rewarded the most productive dairy cows. After calving, these animals give the metabolic priority to the udder, while after fertilization this priority goes to the fetus and the lipid tissue. Thus, the aim of dairy cow nutrition is to adequately return the nutrients removed by the udder, making a part of these molecules available for other metabolic functions such as growth and reproduction.
Buffalo nutrition is less studied than bovine, both for the number of reared animals and their geographic distribution. In Italy, there are many dairy buffaloes, especially linked to typical cheese production (buffalo mozzarella from Campania) so that buffaloes’ nutrition is particularly studied here by researchers and professionals. However, there is no modelization for buffaloes because there is too little knowledge about their requirements and the rumen kinetics of nutrients. The on-farm procedure to determine buffaloes requirements is based on the Institut National de la Recherche Agronomique (INRA) indications about dairy cows: they are standardized for buffaloes milk with 8.30% milk fat, using the equation from Di Palo (1992):
Standardized milk (kg) = milk production (kg) x
Table 1 reports milking buffaloes nutrient requirements indicated by the Technical-scientific Commitee (2002), while Table 2 indicates the ones suggested by Bartocci (2002). Table 3 recaps the dietary practical decisions for milking buffaloes, derived from different authors’ indications.
Table 1: Nutrients requirements for milking buffaloes related to their milk production according to the Technical-Scientific Commitee (2002)
< 6 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | |
DMI (kg) | 13.3 | 14.2 | 14.7 | 15.1 | 15.6 | 16.1 | 16.5 | 17.0 |
ENL | 0.75 | 0.79 | 0.82 | 0.82 | 0.86 | 0.88 | 0.90 | 0.92 |
CP (%) | 13.0 | 13.9 | 14.3 | 14.6 | 15.0 | 15.3 | 15.6 | 15.9 |
NDF (%) | 52.0 | 47.0 | 46.0 | 44.0 | 43.0 | 42.0 | 40.0 | 39.0 |
NSC (%) | 25.0 | 27.0 | 28.0 | 29.0 | 30.0 | 30.0 | 31.0 | 32.0 |
Table 2: Nutrients requirements for milking buffaloes according to Bartocci (2002). Milk production standardized (milk fat 8.30%, milk protein 4.73%)
7 | 8 | 9 | 10 | 11 | 12 | |
DMI (kg) | 16.00 | 16.25 | 16.50 | 16.75 | 17.00 | 17.00 |
ENL | 0.74 | 0.76 | 0.79 | 0.82 | 0.85 | 0.89 |
CP (%) | 10.16 | 11.16 | 12.13 | 13.06 | 13.97 | 15.08 |
NDF (%) | 46.70 | 44.76 | 42.87 | 41.05 | 39.27 | 38.10 |
NSC (%) | 36.35 | 36.71 | 37.07 | 37.41 | 37.75 | 38.63 |
Table 3: Dietary model for milking buffaloes.
Dry matter (kg) | 16.5-18.5 |
Crude protein (%) | 13.5-16.5 |
Starch (%) | 13.23 |
Fat (%) | 3-6 |
Conclusion
Dairy cow nutrition is well standardized and modular according to different rearing types, breeding, and feeds. For buffaloes’ diet formulation, nutritionists’ sensitivity and diagnostic ability are extremely important. A full extension of the CNCPS® methodology to the nutrition of this important animal species would be desirable, with the construction of a specific feed database and an update of the math regressions that make up the model.For more information: marketing@vetagro.comOriginal article here: part #1 and #2.