ANSC 1st Edition Lecture 21 Outline of Last Lecture I Dairy Cattle NE Requirements Particle Size and Adding Buffers to Diet Outline of Current Lecture II Adding Fat to Dairy Cow Diets a Benefits b Sources III Feeding Systems for Lactating Dairy Cows a Traditional Feeding System i Advantages b Total Mixed Ration Feeding System i Advantages IV Body Condition Scoring in Dairy Cows a Target BCS Scores V Nutritional Recommendations a Phase I Early Lactation b Phase II Mid Lactation c Phase III Late Lactation Current Lecture Dairy Cattle Nutrition and Feeding Adding Fat to Dairy Cow Diets Energy density of the diet can be increased by replacing a portion of the grain in the diet with fat fat is 2 5X more energy dense Fat added diets allow more energy intake while avoiding excess starch and low fiber intakes Including more than 8 fat in total diet will cause DMI to decrease fiber digestion to decrease too many LCFAs incidence of digestive upsets to increase Most grains and forages contain about 3 fat Therefore fat can be added to diets at 5 without adversely affecting DMI or digestibility 3 5 milk fat is ideal Benefits of Adding Fat high producing cows during the first 2 5 months of lactation benefit the most from fat added diets These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute cows fed fat added diets typically produce 4 to 6 lbs more milk per day cows fed fat added diets lose less weight during early lactation heat stressed 80 degrees cows eat less and produce less milk heat increment is much lower for fats feeding fat added diets to heat stressed cows is beneficial because heat increment is decreased feeding fat added diets may reduce the incidence of ketosis and enhance reproductive performance more likely to return to estrus and rebreed Sources of Fat for Lactating Dairy Cows Fat Source Fat CP ADF Amount to feed lb day 1 Plant Oil Seed Sources Cottonseed 23 23 35 5 7 Soybean 19 41 6 5 7 Canola 40 20 12 3 5 2 Unprocessed Fat Sources Tallow 99 1 1 5 Hydrolyzed 99 1 1 5 animal vegetable oil blends 3 Processed Fat Sources Ca salts of fatty 85 1 1 75 acids Prilled Fat 99 1 1 5 Can feed more than 7 pounds of soybeans if they are heated Cottonseed is very common in TX Unprocessed fat sources will be hydrolyzed in the stomach negative effect on fiber fermentation Processed fat sources bypass fat not hydrolyzed in rumen go to the small intestine most expensive fat Feeding Systems for Lactating Dairy Cows Traditional Feeding System Forages and concentrates are fed separately Steps to a Traditional Feeding System determine nutrient requirements easy estimate forage DMI difficult in grazing cows estimate forage nutritional quality difficult depends on stage of maturity challenging to formulate concentrate mix to supply nutrients beyond what the forage provides Most challenging No way to regulate what they eat when grazing Advantages harvesting and chopping forages for TMR system is expensive costs of grazing forages is cheap cost of feeding equipment for this system is less expensive Total Mixed Ration TMR Feeding System Forages and concentrates mixed and fed together Steps to TMR feeding system determine nutrient requirements easy estimate forage DMI easy since cows aren t grazing estimate forage nutritional quality easier for harvested forages formulate TMR easy compared to formulating supplement for grazing cows Advantages cows aren t permitted to eat only their favorite forage cows are forced to eat the correct balance of forage and concentrate feeds many small meals are eaten throughout the day helps maintain stable rumen pH easier to feed cows in various production groups reduce the incidence of social dominance Traditional causes greater changes in rumen pH more likely to see decrease in milk fat synthesis Body Condition Scoring in Dairy Cows Important management technique to gauge energy status of mature cows as well as developing heifers Five point boy condition score 1 0 to 1 5 Severe under condition 2 0 to 2 5 Thin 3 0 to 3 5 Moderate 4 0 to 4 5 Fat 5 0 Severe over condition Body Condition Score 2 Rump Area shallow cavity lined with fatty tissue at tailhead some fatty tissue felt under pin bone pelvis easily felt Loin Area ends of short ribs feel rounded upper surface felt with slight pressure depression visible in loin Body Condition Score 3 Rump Area no visible cavity around tailhead fatty tissue is easily felt over whole rump skin appears smooth pelvis is felt with slight pressure Loin Area ends of short ribs can be felt with pressure thick layer of tissue on top only a slight depression in loin Body Condition Score 4 Rump Area folds of fatty tissue are visible around tailhead patches of fat are present around the pin bones pelvis is felt only with firm pressure Loin Area short ribs cannot be felt even with firm pressure no depression visible in loin between backbone and hip bone Target of BCS for Dairy Cattle at Critical Times Time of Scoring Target BCS Reasonable Range Cows Calving 3 5 3 0 to 4 0 Peak Milk 2 0 1 5 to 2 0 Mid lactation 2 5 2 0 to 2 5 Dry off 3 5 3 0 to 3 5 Heifers 6 months of age Breeding Calving 2 5 2 5 3 5 2 0 to 3 0 2 0 to 3 0 3 0 to 4 0 Nutritional Recommendations Early Lactation Phase I Goals to achieve during early lactation Maximize Intake for every 1 lb increase in DMI milk production will increase by 2 5 lb Minimize Body Tissue Loss Most dairy cows will have a negative energy balance during 1 lb of body tissue mobilized during early lactation will supply enough energy for 7 lb of milk enough protein for 3 5 lb of milk Feeding Recommendations use high quality forages i e alfalfa hay use palatable feeds with high energy density ensure adequate effective fiber levels min 20 ADF Consider adding fat to the diet i e bypass fat or whole cottonseed use all natural protein supplements no urea consider use of high quality bypass protein UIP sources Effects of Amount and Source of UIP on Milk Production Feedstuffs Low UIP Diets High UIP low quality High UIP high quality diets diets Corn Silage 50 50 41 8 Corn Grain 28 5 30 4 28 Soybean Meal 6 4 18 3 9 4 11 lysine Corn Gluten Meal 7 1 7 lysine Dried Brewers Grain 16 3 8 lysine Milk Production lb day 68 70 77 The quality of protein of EAA in UIP fed to ruminants is IMPORTANT Mid Lactation Phase II Goals to Achieve maintain high milk production begin to regain body condition lost during early lactation Feeding