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From:
Category: Cattle
Date: 28 Mar 2006
Time: 16:57:45 -0800
Hgih-energy perennial pastures are not the typical route. Most of the cow-calf herds in Argentina receive low quality resources almost all year long and we have some sorry looking herds in many ranches and farms. High-quality perennial pastures are good for a high milking cow (dairy namely). Beef cows do well on such pastures too. However, you have to look at the system. If there is potential for high-quality perennial leguminous pastures, most likely there is room for a sotcker-finishing program too. Such pastures help to regain condition and replenish minerals (cooper, zinc, iron, selenium, magnesium, calcium). But, if the proportion of legumes is too high and legumes lush, the cow could be faced with high ammonia. Ammoniosis can interfere with reproduction and embryo retention. Calf performance of after weaning and the entire length of the finishing period on pasture is highly correlated with the quality of life prior to weaning (weight gain and immune system development). Well nursed, well mineralized (through milk) calves can stand deficiencies later on and perform well in a broader variety of environments. Information says also that the marble easier and more tender beef. A cow-calf follower program works well but it is difficult to implement. More so if places and paddocks are small and labor limited. We may want to look at the fatness or condition of cows on this type of pasture closely, and more so I we are near calving time, at calving and/or in early lactation. Excessive gain in the third trimester can oversize the calf and over fatten the cow. Dystosia becomes a problem. Likewise, if cows are too fat at breeding, we can drop reproductive efficiency (lower heat expression, lower conception rate and lower embryo retention). The first two months after calving milk demands increase but the cow can still gain weight and at a fast rate too. This scenario increases the reproduction performance (reduced anestrous post-calving) and increased fertility (ovulation, conception and embryo retention). At home, we find many systems that are what we call “complete cycle”. The place produces the calves and the calves are reared and finished on the same place. Most of these systems are mixed with grain production, therefore, cows get to graze stabbles 3 to 4 months out of the year. Before calving, the cows are moved to a grassy leguminous pasture, a fescue(endophyte free) or a wheatgrass based pasture (or weeping lovegrass in places). The rule of thumb is: the worse the winter forage the less body condition we allow the cow to lose or, in other words, cows that are thin (4 in 1 to 9) in early fall need to be improved in condition to enter winter. A thin cow on low-quality dormant forages is a high risk cow (winter is going to weaken her with all the consequences: small and weak calf, calving difficulties for lack of energy, abortions, retained placentas, mineral deficiencies, poor nursing after calving, poor expression of genetics). The drier the environment and the more fibrous (lower quality) the forage, the more strict we need to be about cow condition. Always challenge systems for more carrying capacity (stocking rate), grazing pressure or less supplemental feed when cows are in good condition. A system with a poor status (condition) cannot respond to any challenge and need to be fixed first. Going back to cow-calf forage chains, if no stubbles are there, then perennial pastures are used. Most likely the winter forage of these pastures is stockpiled grass from fall and some deferred material. In all cases these pastures keep the cow´s condition score, given that the pasture has some green grass in the winter.