Milk Supplementation beyond the Lactation Period: The Impact on Growth and Health of the Pigs.
By Rafael Cabrera, Ralco Nutrition, Inc. The selection pressure placed on high prolificacy and the high nutrients required in order to support high wean weights have made feeding the modern dam genotype a “State of the Art” work in swine commercial farms.Introduction
The fact that we allow the young gilt to conceive when she is 125-145 kgs of body weight plus mobilizing body reserves to lactate 10-11 piglets is a heavy load if we realize that her maternal body growth is not completed until 200-250 kgs of body weight.
Animal practitioners have felt a great deal of social and moral responsibilities to make every effort to keep every newborn piglet alive after parturition. They also realized that any attempt to improve their daily gain and health during the piglets’ early life (lactation period) will have an impact on subsequent growth and health performance.
This article deals with the use of milk supplementation during the lactation period in order to maximize pig throughput in swine operations given the high prolificacy of modern dam genotypes. It also emphasizes the impact that milk supplementation has on growth and health beyond the period of colostrums during which the sow plays a significant role as well.
Bridging the Gap
The modern prolific sow has the ability to produce as much milk as (expressed on a per unit body weight basis) a high-yielding dairy cow. High prolific sows produce in average 10.9 kg/d of milk and the top 10% maximize their output at 13.6 kg/d. This allows for 256 and 311 g/pig/d of piglet growth respectively in a 21-d lactation period. However this will limit piglet growth if we realize that neonatal piglets (when milk is not being limited) can grow in average 390 g/pig/d in a 21-d lactating period1. This capacity is limited by d 8th during the lactation period when sow milk output becomes a liability for piglets’ growth potential.
There are two significant stages during a 21-d lactation period. The first 7-8 days of lactation when piglets recognized the sow as the “only source of life” and milk output is sufficient for piglet growth. Unfortunately this is the time when 75-80% of the piglets die due to crate space limitation, post-partum sow problems and/or starvation. The second stage is the last 11-12 days when piglet growth outperforms sow’s milk output. The answer to how long you supplement milk during lactation becomes a question of what you are trying to accomplish: reductions of pre wean mortality or increased wean weight. We recommend to supplement milk during the entire lactation period in order to take full advantage of both reduced mortality and increased wean weight.
The problem with milk supplementation in the past has been two fold: 1) the inability to administer the milk replacer in an economic feasible way (milk wastage could be as high as 30-40% when the wrong milk delivery system is used) and 2) the low quality of the milk replacers available in the market. We have been able to engineer milk delivery system which will allow a milk: gain conversion of 1:1 and sometimes even lower than. Our acidified milk replacer has the ability to “clot” or slow down in the small intestine allowing more time for the nutrients to be absorbed.
We have always found positive responses when supplementing our milk replacer for 24-h during the whole lactation period. In a trial done in Mexico with gilts only we were able to decrease piglet mortality by a net 2.2% (10.8% vs. 8.6%) and increase wean weight by 0.7 lbs (9.5 lbs vs. 10.2 lbs). The most comprehensive milk study was done (Table 1) in partnership with large integrator (72,000 sows). We had an increase of 0.5 piglet per litter and 1 lb in wean weight. The milk: gain conversion was 1.04:1. These results can be used as example to model the economic benefits of supplementing milk replacer in swine production systems.
The Penalty of Low Birth and Low Wean Weight
Small birth-weight pigs comprise approximately 12-13% of the litter and they present special challenges to health and profitability in commercial systems. The health concern is based on their apparent failure to thrive in the nursery, during which a number of vaccines are given. Vaccine responsiveness is dependent on nutritional adequacy, health and physiological well-being. Small pigs are considered to be the most ‘viremic’ of the population. A second problem is that their grow rate from birth to slaughter is relatively low, which results in reduced market weight with significant revenue as ‘cull pigs revenue’. Their contribution to revenue is normally less than the sum of financial inputs.
Deen has studied the impact of small birth-weight pigs on profit. He estimated that for a 260-pound market weight target, that pigs weighing <200 pounds, at the time a Finish barn must close out, could cost up to $34/pig due to a cull pig penalty. He estimated that pigs weighing 210 and 220 pounds could result in losses of $12 and $7 per pig respectively. He points out that small birth-weight pigs are naturally more susceptible to disease, which could increase disease spread and cause other pigs to gain more slowly.
By using milk supplementation, we have been able to reduce (Table 1) the percentage of pigs that are less than 8 lbs at weaning by 50%. In another study, a sow farm has usually weaned around 1,800 pigs on weekly basis and reporting 125 pigs rejected by the nursery managers. After we implemented our milk technology in 30% of their crates, the amount of rejected weaned pigs was reduced to 50 pigs (60% reduction). This is a substantial economic advantage considering that those pigs are either destroyed or considered to have “No Value” when sold as weaned pigs. This represents a financial burden considering that this percentage of pigs (< 8 lbs) can be as high as 8-10% in any given swine operation assuming that we have a normal wean weight distribution. Our experience with milk supplementation has demonstrated that supplementing milk helps all size of pigs (small, medium and big) in the crates. We have seen the biggest response in wean weight increase with small and big pigs (1.8 and 1.6 lbs increase respectively) when compared to sow-reared pigs.
Wean weight drives growth both in the nursery and grow-finish. We have conducted one study analyzing the impact of wean weights on days to market (Table 2). We were not surprised to find out that by increasing 2 lbs at weaning (from 10 lbs to 12 lbs) pigs were able to reach a market weight of 275 lbs in 8 days earlier (176.8 vs. 168.8 days). This is an enormous saving in feed cost and barn efficiency.
Can Milk-fed pigs be Healthier?
Milk-fed pigs seem to transition and gain better right after weaning according to our experience with producers using our milk supplementation technology. This observation indicates that feeding a milk replacer during the whole lactation period may not only be beneficial in reaching maximal pig weight gain at weaning but also may have application in the transition from sow’s milk to solid feed.
Research studies have reported that, at 46 d of age, pigs fed liquid milk replacer had accreted more protein (10%), fat (17%), and water than sow-suckled pigs. They have also reported 74% longer villi in the proximal small intestine. The latter may indicate their ability to couple with digestive disorders normally observed after weaning. The increased accretion may come from two sources: sow’s milk and the milk replacer. We have consistently observed milk-fed pigs being more viable and therefore more able to adequately stimulate the sow for increased milk output. The intake of sow’s colostrum (great amount of antibodies or inmunoglobulins) has proven to play an important role in piglet’s health beyond the period of colostrum since no antibodies are transferred to the piglets prior to parturition.
Even though our work has not entailed body composition and small intestinal morphology after feeding milk replacer, we have followed milk-fed pigs and sow-reared pigs from weaning to market, to find differences in growth and mortality. A study of a total of 1,200 (600 pigs per treatment) showed a lifetime mortality difference of 9% in favor de milk-fed pigs in an unstable PRRS positive swine system. Various swine practitioners have explained to us that “the very single reason why they are feeding our milk replacer is because of the improved health shown by milk-fed pigs in the nurseries and grow-finish sites”. This assessment is consistent with our research data.
Concluding Thoughts
The milk supplementation technology has multiples benefits if manage properly. A clear discussion with farm workers must take place in order for them “to buy into it”. It is also beneficial for them to understand that this technology is not a replacement of good animal husbandry practices but a tool which will allow them to step to the next level of pig performance. Training and maintenance of the equipment is vital in order to extract the full benefits that the technology brings.
References
- Boyd, R.D., R.E. Kensinger, R.J. Harrell and D.E. Bauman. 1995. Nutrient uptake and endocrine regulation of milk synthesis by mammary tissue of lactating sows. In International Lactation Biology Symposium (Ed. H.A. Tucker, J.A. Pettigrew). J. Anim. Sci. 73 (Suppl. 3):35-56.
- Deen, J. 2003. The Price You Pay for Lightweights. Pork Magazine, March 2003, p. 33
- Johnston, M. Personal Communication. The Hanor Company, Franklin, Kentucky.
- Wood, Mike. Personal Communication. The Hanor Company, Battlesboro, North Carolina.
- Zijlstra, R.T., K.Y. Whang, R.A. Easter, and J. Odle. 1996. Effect of feeding a milk replacer to nearly-weaned pigs on growth, body composition, and small intestinal morphology, compared with suckled littermates. J. Anim. Sci. 74:2948-2959.