Volumen 2, Número 1

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https://hdl.handle.net/10669/13499

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Consideraciones nutricionales en la formulación y alimentación para postura aplicadas a la explotación de huevos en Centro America
(2013-07-18 00:00:00) Campabadal Herrero, Carlos
Nutritional considerations of feeding laying hen under Central America conditions. Egg production is affected by many factors, which include replacement feeding program, environmental conditions, feed intake, nutrient requirements, type of diets and feeding management program. The most critical factor that affects egg production and egg weight is the feeding program during the growing period. The success of a feeding program is to reach the exact body weight at sexual maturity. Every commercial hybrid has its own ideal weight and it is affected by feed intake, nutrient requirements and feeding program. Environmental conditions are other important factors that affect egg production. High or low temperatures affect feed intake, causing a nutrient deficiency or toxicity which affects the performance of the laying hen.
El balance catión-anión en la nutrición del ganado lechero
(2013-07-18 00:00:00) Sánchez González, Jorge Manuel
Dietary Cation-Anion Balance in Dairy Cattle Nutrition. AReview. Dietary Cation-Anion Balance (DCAB) is a relativelynew concept in Dairy Cattle nutrition and feeding. it is definedas mEq (Na+K)-(Cl+S)/kg of DM. Metabolic acidosis andalkalosis is given by blood protein concentration and byinorganic ions absorbed from the gastrointestinal tract. If weconsider blood protein concentration to be relatively constant,the metabolic acid-base balance of blood and cells is attributedmainly to inorganic cations and anions supplied by the diet.Anions have an acidogenic effect in the organism, while cationsare alkalogenic. Changes in the metabolic acid-base balancecan affect celular enzyme activity and the structure of hormonereceptors, reducing production of the animals and resistanceto metabolic imbalances. However, technical manipulation ofthis balance can contribute to improve health, production andreproduction. Several studies have found that feeding anionic(acidogenic diets) (-100 to -200 mEq/kg of DM) during the last3 to 4 weeks of the gestation period contribute to improvecalcium metabolism and to reduce the level of hypocalcemianormally occurring during the puerperal period, reducing incidence of milk fever and other problems such as retentionof fetal membranes.Also, it has been observed that cows fedthese diets improved milk production in 3 to 7% during thenext lactation, as well as reproduction. About the best DCABto be fed during the lactation period, it has been found thatalkalogenic diets are better for milk production. Some workershave found the best milk production and DM intake feedingdiets with a DCAB of +300 to +500 mEq/kg of DM (calculatedas (Na+K-CI)). Acidogenic salts usually used to feed dry cowsare Calcium Sulfate, Magnesium Sulfate, Ammonium Sulfate,Calcium Cloride, Magnesium Cloride and Ammonium Cloride.Palatability of these salts is low. Diets betvveen -100 to -200mEq/kg of DM have given the best results to reduce incidenceof milk fever. These acidogenic rations should supply between140 and 150 g of calcium per cow per day and must be fed atleast during 10 days prepartum.
El Valor Nutritivo de los subproductos en Costa Rica. Composicion quimica, disponibilidad y uso.
(2013-07-18 00:00:00) Vargas González, Emilio
The nutritive value of rice by products in Costa Rica, Chemical composition, availability and use. By-products from the milling of rice, as obtained in Costa Rica, were examined for chemical composition and availability in the country. Data were taken from the CINA feed data base and from the literature. In Costa Rica, rice bran is a mixture of rice polishings and rice bran, without the broken rice and contain all the layers of the rice obtained in the milling operation of brushing the grain to polish the kernel. It may contain small quantity of hulls and germ of the rice. It must contain no less than 9% of crude protein and no more than 13% of crude fiber. The data show an availability of rice bran of 16.800 tons with an average protein content of 13.6% and 8.5% of crude fiber. The digestible energy swine was 3924 Kcal/kg of dry matter and 3340 Kcal/kg of dry matter of metabolizable energy for poultry. The brewers rice (polished and broken grain) and the rice hulls showed a chemical analysis typical for this type of products' It is suggested to control the marketing of rice bran mixtured with gro.rlá hulls which is illegal in CostaRica' It should be marketed as "bran with hulis".
El yodo en la nutrición del ganado bovino
(2013-07-18 00:00:00) González, Jorge Sánchez
Iodine in bovine nutrition. A review. Iodine is an essencial element in animal nutrition. Although the only function of this element is to be part of the thyroid hormones (thyroxine and triidothyronine); these have an important rol in thermoregulation, intermediary metabolism, growth and development, hematopoiesis and circulation, neuromuscular functioning and reproduction. Iodine is mainly concentrated in the thyroid tissue. In the adult bovine this gland has nearly 100 mg of iodine, which is considered an important amount since this is a micromineral and the thyroid only weights 30 g. Because 90 % of iodine present in the Protein Binding Iodine (PBI) corresponds to tiroxine and 10 %, to triiodothyronine, the analysis of the PBI is are excellent indicator of the iodine nutritional status of the animal. Normal values of PBI range from 2J3 to 4.77 g/700 ml in the different categories of bovines. Iodine content of milk is affected by the level of this element in feed as well as for the use of iodine desinfectants as test dips or udder washes. Milk and milk products are considered a good source of this element for human nutrition. Iodine deficiency is very common and affects mainly inland areas. Low levels in the diet affects reproduction of cows, causing irregular estrous cycles, Iow conception rates as well as resorbed fetuses, abortions, stillbirts or calves may be born with gaiter, blind, hairless or weak. Male fertility may also be affected decreasing libido and semen quality. Likewise, severe Iodine deficiency may reduce milk production or growth rate. A common feeding practice to prevent the deficiency is to supplement salt containing 0.01-0.02% of Iodine' Sources frecuently used to supplement this element are Calcium lodate, Ethylenediamine Dihydriodade and estabilized Potassium todide. Requirements for dairy cattle range from 0'6 mg/Kg of DM for lacting cows to 0.25 for calves, growing heifers and bulls, for the different categories of beef cattle requirements are 0'5' Although bovine can tolerate Iodine levels far in escess of their requirements, a level of 50 mg/Kg of DM has been suggested as the maximum tolerable level. In Costa Rica there is no information of the Iodine contents of forages or soils; because our country is in a Iodine defficient area, feeding practices usually include the supplementation of this element
Uso de la soya en acuacultura
(2013-07-18 00:00:00) Treviño Carrillo, Laura
Use of soybean in aquaculture. Aquaculture profits are closely related to feed supply and feed protein costs. Intensive aquaculture farming requires high protein levels in feeds. Feed is the most important item. commercial feeds formulated for aquaculture species range from 25 to 50% crude protein (Akiyama, 1992). For this reason, high protein ingredients such as fish meal, bone and blood meal and oilseed meals varies from 50 to 70% of the feed formulation. The limited supply and high prices of fish meal had encouraged aquaculture nutritionists to consider other alternative protein sources. Nevertheless, high vegetable protein levels in fish diets generally results in low growth rates and poor feed efficiency ratios due to an incorrect essential nutrients balance, raw material antinutritive factors, low palatability or low water stability pellets (Lil and Dominy, 1991). Among vegetable meals, the soybean meal is increasing its use. This is due to soybean chemical composition, amino acid profile and high availability around the world at lower prices than fishmeal (Akiyama, 1992). Raw soybeans have several antinutritive factors that provokes low growth in cold water fishes. Warm water fishes and shrimps fed with soybean products as the main protein source achieve satisfactory growth. Solvent extracted, dehulled soybean meal is 49% crude-protein, from which, 85% is digestible (for catfish rainbow trout and tilapia), almost the same as fishmeal (Lovell and Smitherman, 1993) and 89.9%, for shrimp (Akiyama et al., 1991). Palatability is the main limiting factor for soybean use in salmon and trout feeds (Lovell and Smitherman, 1993). Whole soybean suitable heated can replace partially (and sometimes totally) fishmeal in freshwater and marine fish' The main recommendation related to whole soybean use in fish diets is not to exceed fat levels for each species. One of the main components of soybean oil is soybean lecithin as a mayor source of coline,inositol and several nutritional components. Besides the protection of soybean-r lecithin to vitamins A and E against oxidation, it promotes a better utilization of fats and vitamins' In extruded feeds, soybean lecithin contribute with the necessary lubrication for tire exit dice, making feed manufacture more efficient (Ruiz, 1990). Full fat soybeans provides a high protein/ high energy source. More research is required in aquaculture species to know certainly the organisms biological response to different ingredients.

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