During the last 3 weeks of gestation, cow’s requirements for energy increase due to fetal development and colostrum production. At the same time, dry matter (DM) intake drops significantly during this period. This mismatch between nutrient intake and demand generates a negative energy balance towards the end of the pregnancy that is prolonged for several weeks after calving.
Sorghum is a tropical grass grown primarily in semiarid and dry regions. It has become an important cereal crop because it is heat and drought tolerant. As forage, sorghum hybrids with the brown midrib (BMR) gene are becoming popular in the U.S. because their lower water requirement compared with corn. Average starch concentration in BMR sorghum silage is lower than in corn silage; however, fiber and fiber digestibility contents are very similar in these forages.
Traditionally, the methods used to detect estrus in dairy cows include visual observation, tail painting, tail chalking, rump-based pressure and scratch-off patches. In high-producing cows, the duration and intensity of estrus behavior is considerably lower than that in dairy cows of a few decades ago.
Pomegranate trees (Punica granatum L.) originate from East Asia and are traditionally grown in semiarid and subtropical areas. Pomegranate fruit consists of three parts: the arils (about 40% of the fruit weight); seeds (10%); and the peels which include the husk and interior network membranes (50%). During the industrial manufacturing of pomegranate juice, large amounts of co-products are produced.
Fungal species of Fusarium produce the mycotoxins deoxynivalenol, fumonisins, and zearalenone. The limits established for dairy cattle by the Food and Drug Administration (FDA) in the US for deoxynivalenol and fumonisin are 5 ppm and 30 ppm, respectively. Although the FDA does not suggest safety guidelines for zearalenone, the European Commission established 250 ppb as the maximum legal limit in complete feed for this mycotoxin.
Rumen buffers such as sodium bicarbonate are commonly included in lactating cow diets to stabilize rumen pH. Recently, calcareous marine algae have been used for buffering dairy diets. Lithothamnion calcareum is a red alga of the Corallinacea family whose main feature is the formation of calcium and magnesium carbonate precipitates in its cell walls. Calcium and magnesium are the major minerals of this alga, and other trace elements include iron, manganese, boron, nickel, copper, zinc, molybdenum, selenium, and strontium.
Methionine and lysine are the main limiting amino acids in lactating dairy cow diets. However, recent research shows histidine may be a limiting amino acid as well. A series of three studies (2015, 2016, 2017) conducted at The Pennsylvania State University’s Dairy Teaching and Research Center reported greater intake and milk protein yield in high-production cows fed low-protein diets supplemented with rumen-protected (RP) histidine.
There are a wide variety of forage crops used in the United States for dairy farms. One of the most common is oat as it provides the benefit of diversifying crop rotation. In fact, over 1.3 million hectares of oat were planted in the United States with over 60 percent of the output used for forage.