Archive for the 'Swine' Category
Ingredients | Nutritional programs for newly weaned pigs are very different from those for older pigs because of the immaturity and rapid development of the digestive and immune systems of the young pigs. While nutrient levels are important in all diets, the focus in designing diet for young pigs is on nutrient sources (ingredients). In fact, we use several special (and expensive) ingredients in diets for nursery pigs that we do not use in diets for older pigs. The younger the pig is a weaning; the more important are these special ingredients.
Specific ingredients appear important in the diet of new weaned pigs, although we do not clearly understand the physiological mechanisms. That includes spray-dried plasma, soy products and a small amount fish meal. High levels of soybean meal should be avoided. The ingredients can supply the bioavailable amino acids needed, including pet food-grade poultry meal, further-processed soy product, spray-dried blood cells, dried porcine solubles, higher levels of fish meal and crystalline amino acids.
Phase feeding | The special ingredients become gradually less important as the pig matures after weaning. They are expensive, so it is important to use as little of them as necessary. Therefore, we use a small amount (perhaps only a pound per pig) of an expensive diet containing high levels of these ingredients immediately after weaning, then move promptly through a series of diets with declining cost and declining levels of special ingredients, using a feed budget. Note that phase feeding for nursery pigs changes primarily nutrient sources, while phase feeding for finishing pigs changes nutrient level. Both are designed to control costs.
April 09 2008 | Swine | No Comments »
Dietary allowances for lactating sows | High intake needed
Modern sows can produce impressive quantities of milk, and that requires large amounts of energy, amino acids and other nutrients to support that milk production. It is, therefore, important that sows consume enough feed to supply those nutrients Inadequacy of nutrient intake can reduce milk production and/or cause mobilization of excessive amounts of maternal body tissue. It can also create metabolic/endocrine conditions that reduce the quality of the developing ovarian follicles that will produce the next litter of piglets.
Achievement of adequate feed intake by lactating sows is both very important and very difficult. However, feed intake can be encouraged by appropriate management. Heat stress should be minimized by appropriate environmental management steps, such as drip-cooling. The feeding process should be managed to encourage a high level of feed intake.
Fat | Supplementation of lactation diets with fat is unlikely to improve subsequent reproduction in most cases, but it almost always increases litter weaning weights and is recommended for that reason. This appears to be a specific physiological effect of dietary fat, not of energy density.
Amino acids | The amino acid requirements of lactating sows can be estimated by a factorial approach, as described above for finishing pigs. The factors to be considered are maintenance, requirements of the mammary gland for milk production, and the amino acids contributed by mobilization of maternal tissue. Again, the requirements for amino acids other than lysine are estimated using ratios.
The lysine requirement for maintenance is the same in relation to bodyweight as for finishing pigs. The requirement for the mammary gland is estimated to be 22 g apparent digestible lysine/kg litter growth.
Recent research from our laboratory indicates that the NRC (1998) estimate of the Valine:Lysine requirement ratio for milk production is too high. Correction of that ratio downward will allow use of more crystalline amino acids.
April 08 2008 | Swine | No Comments »
Dietary Allowances for Swine
Energy| Gestating sows differ from pigs in most other stages of production in needing a restriction of feed intake. That creates substantial challenges in the physical management of feed delivery, to ensure that each animal consumes the target amount of feed. Sows that consume too little during gestation enter the challenging lactation phase in a precarious condition with limited body stores of fat and protein to draw upon. Sows that consume too much during gestation eat too little during lactation, when adequate energy intake is most critical.
The fact that the energy requirement of gestating sows is less than their voluntary intake allows the use of fibrous ingredients in the diet, without reducing performance.
Amino acids | The amino acid requirements of gestating sows are relatively low during most of gestation because most of the energy is used for maintenance and the amino acid requirements for maintenance are low relative to the energy requirement. Requirements for both energy and amino acids increase markedly in late gestation.
April 07 2008 | Swine | No Comments »
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