Post-weaning Performance Research Articles

Symposium on Performance Testing in Beef Cattle: Evaluating Postweaning Performance in Beef Cattle

The format of this symposium indicates that it is the intent of the program committee that this discussion be concerned primarily with postweaning growth rate with perhaps some treatment of postweaning feed efficiency. To the extent that postweaning growth rate and feed efficiency may be genetically associated with other traits, such associations may be considered. To put things in perspective, it is appropriate to review the primary interests of the different segments of the beef cattle industry. The commercial producer is interested in cows with a long productive life that wean a high percent of heavy, high grading calves; the feeder desires rapid and efficient feed lot gains; and the packer and retailer are interested in the maximum amount of edible portion per unit of live or carcass weight. The consumer expects this edible portion to be tender, flavorful and juicy. Thus, this particular discussion involves the traits that are of direct concern to the feeding segment of the industry.

Post-Weaning Performance in Columbia and Corriedale Lambs

Post-Weaning Performance in Columbia and Corriedale Lambs

Influence of Dam's Milk Production and other Factors on Post-Weaning Performance and Carcass Characteristics of Hereford Cattle

Influence of Dam's Milk Production and other Factors on Post-Weaning Performance and Carcass Characteristics of Hereford Cattle

Effect of environmental temperature on suckling pigs and a study of the milk yield of the sow

1. A study was made of the performance of eight litters of pigs housed under two widely different levels of ambient temperature during the suckling period and under uniform conditions from weaning to 200 lb. live weight.2. There was no significant treatment difference in the amount of milk suckled, but the pigs exposed to the lower temperature consumed more solid food before weaning.3. Up to weaning those kept at the higher temperature were the more efficient converters of milk and solid food into live weight.4. There was a highly significant correlation between milk suckled and live-weight gain.5. Probably through excessive handling, the pigs were under weight at weaning, but the postweaning performance appeared to be unaffected by the pre-weaning treatment.6. The average milk yield of six sows from the 3rd to the 56th day of lactation was 275 kg. 605 lb.) (variations 202–347 kg. (445–764 lb.)). Yields have been compared with others published.7. After allowing for maintenance requirements and weight gain or loss it is estimated that the sows required 412 Calories of net energy to produce 1 lb. of milk.

Development of Practical Synthetic Milk Formulas for Baby Pigs

Three experiments were conducted to develop a practical synthetic sow-milk substitute and to study its performance under experimental farm conditions. In the apparent absence of disease, it was possible to raise 14 pigs, which had not received colostrum, on a vitamin, mineral and antibiotic fortified dried skimmed milk ration including lard. The addition of casein did not improve growth but without lard the pigs died. After an outbreak of transmissible gastroenteritis in the second experiment, it was impossible to raise pigs without colostrum. Six lots of 10 pigs raised from 2 days of age in concrete-floored pens indicated that 56-day weights were not reduced by discontinuing milk feeding at 5 weeks as compared with 7 weeks of age. In a third experiment, twenty lots of 5 pigs each were raised successfully from 3 days of age in radiant-heated, concrete-floored pens. Of the 10, 20 and 30 percent fat levels, the lowest level produced the best growth. A level of 15 percent solids was superior to 20 or 25 percent for growth, feed efficiency and physical reconstitution. When fed at equal levels, a combination of terramycin, streptomycin, penicillin and rimocidin gave no better results than terramycin alone. The inclusion of 10 percent condensed fish solubles failed to improve performance. Doubling the vitamin fortification did not improve gains or feed efficiency. This would indicate that sufficient vitamin fortification was provided in the basal synthetic milk and that the vitamins were sufficiently stable in the milk solids and in the reconstituted milk. The 97 pigs raised averaged 49.8 pounds at approximately 8 weeks of age and consumed an average of 22 pounds of milk solids and 60 pounds of pig starter to this age. Post-weaning performance of the pigs fed synthetic milk was satisfactory. The results of these experiments indicate baby pigs can be raised successfully from 2 to 3 days of age in concrete-floored pens on synthetic milk rations composed of dried skimmed milk, lard, essential minerals, vitamins and antibiotics.