Heifers in field natural service

Rebreeding always includes pasture management up to 600 days, when the genetic evaluation is completed. It is managed on grasslands and is supplemented during winter with hay rolls, which are obtained by our own personnel and machinery from the spring/summer surplus fodder of grasslands.
Today, we intend that weaning takes place late whenever possible. It occurs in September/October for autumn births and March/April for spring births. This improves global pasture management as it gives grasslands a longer break while live products complete the initial pasture development.

Heifers for first service	Selecting bulls in holding pens

When calves are weaned, calves and breeding cows are officially weighed to obtain the 200-day weight and mature cow weight, respectively. With the projected EBVs available since birth, a minimum discarding of males may be done by castration. At that moment, work is done on at least two or three batches of males and females, according to the Pampa Index, age and/or weight, to facilitate nutrition and subsequent management.
In winter, night penning is performed supplemented with hay rolls. If there is any surplus, animals are also fed with corn silage, sometimes with grains added, but in limited amounts for maintenance.  Some time ago, oats have been suppressed as winter grass for cost and cultivation uncertainty reasons.

6-month-old bull calves	CSM 7824, son of Lihuén by Rollizo

In the case of females, in late October they are submitted to the 400-day or 600-day weighing according to their age, and it is decided which ones will be selected for artificial insemination and which ones will be intended for natural service because of lateness or unworthiness.

Luciana Hernández and Mauro Berrueta scanning

The final weighing of females takes place when they are 18 months old. At the same time, the carcass ultrasound scanning is performed for all autumn and spring births in November and February, respectively, by Mauro Berrueta and Luciana Hernández, who send the images to the INTA Laboratory in Castelar for their reading, and then the Angus Association informs the results. After receiving the final EBVs (interim EBVs are asked to Australia to be able to use them quickly for the preparation of the sale catalogue of the autumn auction), the final selection of breeding cows to be kept for replacement is made and the remaining breeding cows are intended for sale.
As in the case of females, males are weighed every two months during rebreeding, seizing the opportunity to vaccinate and worm them. However, the official measurements considered are those corresponding to 400 days (when the scrotal size is measured) and 600 days (when the carcass measurement is made). Until then, management is done in three or four batches of similar weight which have always been fed on grass.

Rolling hay	Bull calves supplemented with hay rolls in July

Replacement bulls for the stock of 20 sires are selected when full genetic information, in addition to the tenderness markers nowadays required, is available. It is usual and natural that every year animals superior to those selected the previous year appear; in general, they are offspring of heifers or young females. Of course, candidates for sire selection are intended to have good genetic information but also good structural, breed and esthetic conditions.

Home-made feedlot	2007 snowfall at Casamú. Night penning

For three years now, we have been implementing feedlot finishing during 90 days prior to auctions but after the final growth and carcass evaluation exclusively in pasture conditions, because we want genetic information to truly show the individual successes achieved in natural conditions.
In this pen, after being fed with hay rolls during a few days, they are supplied with corn silage, corn grains, a mineral concentrate and urea. We have observed that this is an efficient and safe system that allows to relieve pressure on grazing and increase it on minor rebreeding. In addition, animals are presented for sale in the conditions appreciated by buyers.

Chopping corn for silage	Preparing the silage

Rolling the silage	Feedlot breeding of sale stock, 80 days before auctions