Nutrition
Nutrition Articles
Pasture Ready Herds Follow a Plan
Cattle will soon be going on to pastures with the arrival of the warm weather and relatively good moisture situation. The thoughts of the producers now turn to ensuring the lactating cow has ample pasture to produce milk and repair body tissue so the upcoming breeding season goes well. Last year pasture forages were slow to come so feeding continued several weeks longer but we had an improvement this spring though it is a slow start. Accommodating the shortfall in feeding will help the herd reach the desired 92% to 95% pregnancy rate needed to keep the herd in the top 25% of herds for calving and keep the profitability high. The value of calves and cows is high and working to keep body condition score high pays in many ways. Cows experiencing more than a drop of 1 BCS also don’t ovulate as consistently as cows that have a steady body condition.
Fresh grass growth contains about 25% dry matter and the average cow with a calf nursing needs to consume 30 to 35 pounds of dry matter per day to achieve intake of the needed nutrients depending on body weight and milking ability. This translates into 125 lbs. to 140 lbs. of pasture forage daily which is a lot for new growth in the spring. Stocking rate can be calculated by clipping forages from a measured amount of ground, for example a square meter (10.77 ft2) and animals assigned accordingly. A miscalculation at this stage predisposes a cow to poor ovulation and also early embryonic mortality. Thin stands mean a lot of distance to cover for cows and the possibility of not getting the needed amount of daily feed. Dr. Michael D’Occhio, honorary Professor with the School of Life and Environmental Sciences at the University of Sydney, highlights an aspect of reproductive performance that attracts less attention than it should, the period between fertilization and pregnancy.
Healthy animals which have been prepared properly will successfully mate and achieve fertilization rates approaching 95%. Subsequently, the “good” cows will continue pregnant but the “poor” cows may not achieve implantation or further development of the calf embryo. “Around 25-30pc of embryos do not survive to day-seven after fertilization, another 10-20pc do not survive to day-14, and another 5-10pc do not survive to day-21. This means that 40-60pc of embryos do not establish a pregnancy. The typical scenario, therefore, is that heifers and cows go through cycles of mating/fertilization/embryo loss, until an embryo survives to establish a pregnancy. Fertility has a genetic component, and the challenge is to identify those genes that support embryo survival and pregnancy in heifers and cows. Genes favourable for embryo survival would be carried by both bulls and cows. Matching ‘good’ bulls for embryo survival with ‘good’ cows would be the ideal.”1
With this scenario nutrition and herd health will either support or antagonize the potential pregnancy. Management activities during this period we are entering, and are now in, predisposes the animal for an outcome. Bulls will be going out in a general way in late May or early June for the March calving herds. Earlier calving means that all cows are being control fed which allows for more exact influence for the top and bottom cow groups in the herd. On pasture herds have free access to fresh forages so minerals and energy/protein intakes need to be estimated. Supplemented grazing has a place and to provide good mixed supplemental feed consider the newly introduced Highline® AMX850T twin screw mixer to support BCS and good intake of minerals, protein and energy during this critical pre-breeding period. Feeding to meet the nutritional needs of the herd gives the best chance that genetics promises are realized.
Highline® has a dedicated team designing and building quality mixers, tools to help farmers in precision feeding their animals.
1. Embryo survival: The hidden reproductive loss in cattle, Beef Central/Genetics 18/05/2021; Dr. Michael D’Ochio, School of Life and Environmental Sciences at the University of Sydney, Australia