In Journal of Animal Science, L.D. Skinner and colleagues at the University of Guelph in Canada report an experiment conducted to examine the effect of the nursery feeding programme on subsequent growth performance, carcass quality, meat quality, and physical and chemical body composition of growing-finishing pigs.

Four dietary treatments were used in a 2×2 factorial arrangement of treatments based on diet complexity (complex versus simple) and in-feed antibiotics (2,730 versus 0 mg of chlortetracycline per kg; AB+ and AB-, respectively.

A total of 552 pigs, in five blocks, were weaned at 21±2 days of age with an initial bodyweight of 7.03±0.07kg. Each experimental block had three pens per treatment, with eight pigs per pen in blocks 1 and 2, and 10 pigs per pen in the remaining three blocks.

Nursery diets were fed in a three-phase feeding programme (Phase I, II and III diets fed for one, two and three weeks, respectively). All pigs were fed common grower-finisher diets thereafter.

Six pigs per treatment were slaughtered for chemical body composition analysis at weeks 2, 8, 12 and 17 post-weaning. An additional 11 pigs per treatment were slaughtered at week 17 post-weaning (approximately 115kg bodyweight or market weight) for analysis of carcass characteristics, chemical and physical body composition, and meat quality.

During the nursery phase, average daily gain was lower (P<0.05) for pigs fed the simple diet than those fed the complex diet (491 versus 528g per day).

Antibiotic usage improved (P<0.05) average daily gain in Phases II (408 versus 438g per day) and III (689 versus 720g per day).

In Phases I and II, gain:feed ratio was lower (P<0.05) for pigs fed the simple diet than those fed the complex diet (0.46 versus 0.58 and 0.75 versus 0.78 in Phases I and II, respectively).

During the grower phase, pigs previously fed AB- diets grew faster than pigs fed AB+ diets (P<0.05; 1,009 versus 971g per day).

There were no treatment effects on overall average daily gain or gain:feed ratio from weaning to finishing.

Nursery feeding programme did not affect carcass quality characteristics. However, pigs previously fed AB+ diets tended (P=0.07) to have increased LM depth.

Nursery feeding programme had no effect on objective or subjective meat quality measures, chemical body composition or the weight of primal and retail carcass cuts 17 weeks post-weaning, with the exception of primal belly weight.

The Guelph-based group conclude their results indicate that feeding simple nursery diets, or nursery diets without antibiotics, compromises growth performance during the nursery period but does not affect overall growth performance between weaning and market bodyweight, carcass characteristics and meat quality.

Thus, feed costs for nursery pigs can be reduced by feeding simple diets without compromising market bodyweight and carcass and meat quality, added Skinner and colleagues.

Reference

Skinner L.D., C.L. Levesque, D. Wey, M. Rudar, J. Zhu, S. Hooda and C.F.M. de Lange. 2014. Impact of nursery feeding program on subsequent growth performance, carcass quality, meat quality, and physical and chemical body composition of growing-finishing pigs. J. Anim. Sci. 92:1044-1054. doi: 10.2527/jas.2013-6743

March 2014