- SECTION 1: PRINCIPLES OF DIET FORMULATION
- PRINCIPLES AND DECISIONS MAKING IN DIET FORMULATION
- SECTION 2: NUTRITIONAL COMPONENTS
- PROTEIN AND AMINO ACIDS
- MACRO MINERALS
- TRACE MINERALS AND VITAMINS
- FEED ADDITIVES
- UPPER LIMITS OF USAGE FOR FEED INGREDIENTS
- SECTION 3: NUTRITION PROGRAM BY PHASE OF PRODUCTION
- THE BASIC NUTRITIONAL PROGRAM
- SOW FEEDING MILESTONES
- DYNAMIC DECISION MAKING TOOLS
- CARCASS QUALITY
- FEEDINGS PIC PIGS UNDER SPECIFIC PROGRAMS
- FEED MANUFACTURING
- FEEDING SYSTEMS, FEEDER SPACE, DRINKING SYSTEMS
THE BASIC NUTRITION PROGRAM
This section will cover basic concepts for feeding PIC pigs during the different phases of production. The nutrient specification tables at the end of this manual provide specific recommendations about nutrient levels of the diets.
Underfeeding boars can have negative consequences in sperm production (PIC Technical Memo 142). The energy needed to support body condition without compromising sperm output has been calculated and validated in AI studs (Table I1; see PIC Technical Memo 142, available on request).
TABLE I1. FEED LEVEL IN RELATION TO BODY WEIGHTa.
Feed intake levels will depend on the body weight of the boars in the stud. With the nutrient levels provided on the specification table at the end of this manual, the typical feed intake is 2.5-2.7 kg. Thin boars are normally fed 2.7 kg/d, ideally conditioned boars are fed 2.5 kg/d, and fat boars are normally fed 2.3 kg/d.
Very little information exists on which to base nutrient specifications. Those presented at the Nutrition Specification tables are used by PIC and given for reference only. Energy and amino acid levels are based on limited university research.
There is some evidence that 0.3 ppm of organic selenium may help maintain sperm motility after consecutive collections, may help ameliorate the negative effects of semen storage on semen motility, and lastly, improve in vitro fertilization rates (Speight et al., 2012).
It has been reported an increase of 11% in total sperm per ejaculate after boars being fed for 16 weeks with 0,295 kg/d of a top-dressed supplement containing 31% omega-3 fatty acids (Estienne et al., 2008). A recent study has reported an 11% increase in semen doses produced when feeding 2000 FTU of Quantum® Blue/kg of diet (Stewart et al., 2016). Another recent study has reported a marginally significant increase in total sperm production of 6% for boars fed 16.3 g/d of a product with 96% betaine during summer months (Cabezón et al., 2016a). More research is warranted to further validate these findings.
Gilt development and management begins in the early stages of a gilts life and ends when the gilt completes her first lactation (Boyd et al., 2002).
The goal is to have an average daily gain from birth to first service of 0.61 to 0.77 kg/day.
The minimum individual weight at breeding is 135 kg. Thus, the average group weight will be, approximately, 145 to 160 kg. Breeding weight above 160 kg should be avoided. Below 135 kg there is a reduction in prolificacy and above 160 kg there is an increase in cost for energetic maintenance, increased weight loss during lactation due to low feed intake, increased chances of locomotor problems, and increased rate of early culling.
For further information about the management of the developing gilt, please refer to the Gilt and Sow Manual published by PIC at http://na.picgenus.com/resources.aspx.
As a summary, key differences between a gilt development diet and a market gilt diet are:
- Vitamins specific for reproduction purposes (i.e., folic acid, biotin, etc)
- Vitamin and trace mineral recommendations are higher than commercial recommendations in order to not limit the gilt for reproductive function (see requirement tables).
- Higher Ca and P levels compared to market gilts.
GESTATING GILT AND SOW
Managing body condition (Figure I1) is a key aspect of a high performance sow farm. An ideally conditioned sow is the one that the back, hip, and rib bones cannot be seen but can be felt when touching the sow. If these bones cannot be felt by touching the sow, then she is over conditioned. The target is to have 90% of the sows in ideal condition.
FIGURE I1. BODY CONDITION SCORE (ADAPTED FROM DISEASE OF SWINE, 2006).
Fat sows at farrowing will likely have low feed intake during lactation, lose more weight (Figure I2), produce less milk, and consequently, may wean lighter piglets. This negative energy balance will then likely influence a reduction in the subsequent litter size.
FIGURE I2. GESTATION AND LACTATION SOW BODYWEIGHT (BW) CHANGES ARE INVERSELY CORRELATED (REN ET AL., 2015).
A recent descriptive summary of experiments (Table 9B) evaluating increased feed intake during late gestation has shown that sow BW is increased by approximately 6.9 kg when bump fed an extra 0.9 kg/d during late gestation. Similarly, the overall effect of bump feeding on piglet birth weight was modest (1 oz or 28 g). This effect is greater and more consistent in gilts (31 g) compared to sows (11 g). In fact, multiple studies have shown negative effects of bump feeding in sows (Shelton et al., 2009; Soto et al., 2011; Greiner et al., 2016).
TABLE I2. DESCRIPTIVE SUMMARY OF EXPERIMENTS EVALUATING INCREASED FEED INTAKE DURING LATE GESTATION (GONÇALVES, 2015).
Additionally, a recent study using 1,102 PIC females (14.2 and 15.2 total piglets born for gilts and sows, respectively) where 15,979 piglets were weighed individually at birth in commercial research conditions suggests that the effect on birth weight is driven by energy (Figure I3) from starch rather than amino acid intake (Gonçalves et al., 2016b). In the same study, bump fed sows had an increase of 2.1% stillborn compared to sows that were not bump fed (Figure I4). This negative effect was not observed in gilts.
FIGURE I3. ENERGY WAS THE DRIVER OF THE MODEST INCREASE IN BIRTH WEIGHT OF PIC PIGLETS RATHER THAN AMINO ACID INTAKE (1,102 PIC FEMALES AND 15,979 PIGLETS WEIGHED AT BIRTH; GONÇALVES ET AL., 2016B).
FIGURE I4. BUMP FEEDING CAN INCREASE 2.1% STILLBORNS IN SOWS, BUT NOT IN GILTS (DIET WITH 3307 KCAL ME/kg; GONÇALVES ET AL., 2016B).
The NRC (2012) suggests that requirements during gestation are higher with large litter sizes. However, daily requirements are not only for fetal needs but a high proportion is for maintenance and growth of the breeding female (Figure I5). Thus, nutrient requirements have not changed greatly enough to have a dramatic requirement update for gestating sows. This has been confirmed by multiple studies that were unable to increase sow reproductive performance by increasing energy and amino acid intake (Ampaire and Levesque, 2016; Buis et al., 2016; Gonçalves et al., 2016b; Greiner et al., 2016). It seems that sows prioritize the fetuses in late gestation at the expense of body weight gain (Theil et al., 2014; Gonçalves et al., 2016b). The PIC Global nutrition team along with the top universities and production systems around the globe will continue to monitor requirement changes as litter size and litter weight changes and updated information will be sent through PIC nutrition updates. At this point, bump feeding is only recommended for ideally conditioned gilts and thin sows.
FIGURE I5. PREDICTED TOTAL PROTEIN GAIN FOR DIFFERENT PROTEIN POOLS THROUGHOUT GESTATION (NRC, 2012).
Feeding management during the pre-farrowing period has been an area of increased interest by researchers (Cools et al., 2014; Decaluwe et al., 2014). Cools et al. (2014) showed that providing ad libitum feed prior to farrowing for fat sows reduced weaning weight and piglet growth rate, but no negative effects on sows that were thin or in ideal condition. Anecdotal evidences have made some veterinarians and nutritionists theorize that providing ad libitum feed prior to farrowing, especially in herds with too many fat sows and that induce farrowing may increase the risk of uterine and rectal prolapses. Current views have theorized that long term ad libitum feeding prior to farrowing may have negative effects on the lactating sow and that fat sows may have weakened uterine muscle tone and increased dystocia (Almond et al., 2006). At this point, there is no strong evidence to recommend more than 7.63 Mcal ME or 5.65 Mcal NE per day prior to farrowing to wellconditioned gilts and sows.
The positive effects of maximizing feed intake in PIC lactating females have been shown in multiples studies to maximize feed intake, milk yield, and piglet weaning weight (Figure I6) while minimizing sow weight loss (JBS United, 2009; Sulabo et al., 2010). Lactation feed intake (Figure I7) and energy intake (Figure I8) curves for different parities are presented below. Additionally, ensuring that the feeder is correctly adjusted and have fresh feed is extremely important (Figures I9 and I10).
The factors that can affect lactation feed intake are:
- Air velocity
- Ambient temperature
- Evaporative cooling
- Ventilation rates
- Facilities equipment
- Feeder design
- Automated vs. hand feeding
- Floor surface
- Crate design
- Water flow
- Gestation feed intake
- Body condition at farrowing
- Sow factors
- Lactation length
- Litter size
- Feeding frequency
- Feed allowance
- Feed freshness
- Feeder adjustment
- Water availability
The farm-specific Lys level for lactation depends on the actual litter growth rate and average lactation feed intake by sows. The daily Lys requirement is driven strictly by rate of litter growth and this can vary with health and thermal stress. This needs to be matched with the level of feed consumed. Table I3 could be used to derive farm-specific lysine needs. Start-up farms may need higher Lys level to maximize second litter size (Boyd et al., 2000). In the absence of other information, a typical starting point would be 1.05 to 1.10% SID Lys for stable herds and 1.15 to 1.25% SID Lys for gilts in start-up farms depending on feed intake. Finally, Table I4 shows that high lactation intake reduces sow body weight loss, increases piglet ADG, and reduces wean-to-estrus interval.
FIGURE I6. SOWS PROVIDED AD LIBITUM FEED DURING LACTATION HAVE INCREASED PIGLET WEANING WEIGHT (SULABO ET AL., 2010).
FIGURE I7. FEED INTAKE DURING LACTATION FOR PIC FEMALES WITH DIFFERENT PARITIES (2.50 MCAL NRC NE/kg DIET; CABEZÓN ET AL., 2016B).
FIGURE I8. NET ENERGY INTAKE DURING LACTATION FOR PIC FEMALES WITH DIFFERENT PARITIES (ADAPTED FROM CABEZÓN ET AL., 2016B).
FIGURE I9. CORRECTLY ADJUSTED LACTATION FEEDER WITH FRESH FEED.
FIGURE I10. INCORRECTLY ADJUSTED LACTATION FEEDER WITH MOLDY FEED.
TABLE I3. LACTATION LYSINE LEVELS BASED ON LITTER GROWTH RATE AND SOW FEED INTAKEa.
TABLE I4. EFFECTS OF FEED INTAKE DURING LACTATION ON WEAN-TO-ESTRUS INTERVAL, BODY WEIGHT LOSS, AND PIGLET AVERAGE DAILY GAIN (GREINER ET AL., UNPUBLISHED).
Feeding management of the weaned sow requires a balance between providing enough fresh feed and avoiding wastage (Figures I11 to I13). Where possible, the weaned sow should be fed 2 to 3 times per day. To maximize feed intake, typically, the wean row would have a water nipple for every sow or shared between two sows.
An internal PIC observational study with 670 sows observed that increasing feeding level from 2.6 to 4.2 kg/d during the wean to service period reduced wean to estrus interval from 5.3 to 4.4 d, increased percentage of sows bred by d 7 from 92.8 to 97.5%, and increased subsequent litter size by a full pig from 12.9 to 13.9. Graham et al. (2015) used 637 sows and fed 2.7, 3.6, or 5.4 kg/d of a diet containing approximately 2.44 Mcal NE/kg from weaning to estrus. They achieved NE intakes of 6.5, 8.6, and 12.6 Mcal per day. They found no statistical difference in wean to estrus interval (5.1, 5.0, or 5.0 d), conception rate (95.6, 95.6, or 94.7%), farrowing rate (85.4, 87.0, and 82.3%), or born alive (13.1, 12.9, or 12.9) for sows fed the 2.7, 3.6, or 5.4 kg/d, respectively. Parity of the sow did not influence the response to feeding level. Graham et al. had only ideal and fat sows in their study, thus may have limited the benefit of high feed intake, and thin sows may still benefit from higher feeding levels. Ad libitum feed intake vary with season and parity profile of the weaned group, thus, to maximize feed intake, sows in the weaning row are typically fed twice a day. Additionally, there is great variation on voluntary feed intake among weaned sows. Thus, identifying thin sows with high voluntary feed intake and adjust feed drops accordingly is key to meet their daily needs. Given the limited research and conflicting results in this area to this point, current PIC recommendation is to feed thin sows ad libitum and ideal/fat sows a minimum of 3.6 kg until further research.
FIGURE I11. FEEDER IN THE WEANING ROW WITH NOT ENOUGH FEED.
FIGURE I12. FEEDER IN THE WEANING ROW WITH ADEQUATE AMOUNT OF FEED.
FIGURE I13. FEEDER IN THE WEANING ROW WITH FEED WASTAGE.
The nursery feeding program corresponds to, approximately, 10 to 15% of total feed cost for producing a pig. Due to the high input costs of the dairy products and high-quality protein in early nursery diets, these ingredients must be reduced quickly after weaning.
Weaning age is an important factor affecting nursery diet formulation because it directly impacts pig performance and profitability. From a nutrition perspective, this is driven by the weaning of a pig that is more physiologically mature and better able to transition to dry feed. Many global production systems are currently increasing weaning age as it is estimated that increasing weaning age from 18 to 21 days of age can increase profitability by approximately US$1 to 2.5 per pig or US$25 to 65 per sow space per year after accounting for increased use of lactation space (Main et al., 2004).
Ad libitum access to feed and water in the nursery phase from the first hour after placement is essential and can greatly impact the weight at the end of the nursery. Weaned pigs are extremely dependent on energy intake and, thus maximizing feed intake is essential. Increasing feed intake during the first week increases digesta flow and decreases proliferation of bacteria in the gut and reduces the incidence of diarrhea. A large epidemiological study indicated that low feed intake after weaning increases the likelihood of developing diarrhea compared to high feed intake (Madec et al., 1998). Therefore, age at weaning and high feed intake after weaning are critical to maximize performance in the nursery phase. For information on management aspects that can improve feed intake after weaning, please refer to the PIC Wean to Finish Manual at http://na.picgenus.com/resources.aspx.
Based on the development of the digestive system of weaned piglets, typically 3 to 4 diets are fed during the nursery period (Table I5).
3.5 to 7.5 kg pigs
Weaning pigs lighter than 5.5 kg pose a great challenge for the adaptation to the nursery environment and feed and therefore, it is strongly encouraged to develop production flows and systems that do not routinely produce average weaning weights below 5.5 kg. Feeding pigs below 7.5 kg requires a diet designed to maximize feed intake. Therefore, these diets typically have a greater cost per ton compared to the subsequent phases due to greater inclusions of highly digestible carbohydrates and protein sources (i.e., fish meal, animal plasma, enzymatically treated soybean meal, etc.). The most commonly used highly digestible carbohydrates are sources of lactose (dried whey, whey permeate, etc). Other highly digestible carbohydrates sources can replace part of the lactose if input prices offer economic opportunities (i.e., maltose, dextrose, micronized corn, micronized rice, maltodextrin, etc). Care must be taken with the source of lactose and generally, ediblegrade lactose sources are the preferred option (Bergstrom et al., 2007). Similarly, there is evidence that different sources of fish meal (i.e., with different crude protein, ash, and oil levels) have different effects on performance (Jones et al., 2015).
The SID lysine in this diet is slightly higher than in the late nursery diets. A standard practice is for a small inclusion of soybean meal to aid in the adaptation of the pigs to a simpler diet in subsequent phases; however, it is important to consider the quality of available soybean meal (i.e., anti-nutritional factors, crude protein levels, and overheating). Research has shown that high inclusion of feed-grade AA (up to 0.50% L-Lysine-HCl) can be used as partial replacement of specialty proteins as long as the requirement of the other essential AA are met (Nemecheck et al., 2011).
7.5 TO 11.5 KG PIGS
This phase has lowering levels of highly digestible protein and carbohydrates sources but increased levels of soybean meal. For lactose sources, dried whey is preferred however high quality whey permeate can partially replace lactose.
11.5 TO 23 KG PIGS
This diet is primarily comprised of a grain source, soybean meal and synthetic amino acids and generally contains very similar ingredients to diets of finishing pigs. It is of extreme importance to adapt the pigs to start the consumption of grain soybean meal-based diets as soon as possible. Minor adjustments in diet formulation of this phase can bring positive economic benefits due to the large impact in the total nursery cost (approximately half of the total nursery feed cost).
TABLE I5. EXAMPLE FEEDING PROGRAM AND FEED BUDGETa.
The steps in diet formulation of finishing pigs are:
- Determine the most economical energy level;
- Determine the lysine:calorie ratio to use for the gender;
- Determine the ratio for the other amino acids;
- Determine the available or digestible phosphorus level;
- Set levels of calcium, vitamins, trace minerals, salt, and other ingredients.
In a review from the literature, Tokach and Gonçalves (2014) summarized the key concepts related to energy and amino acids in the feeding of finishing pigs:
Dietary energy. The pigs’ nutrient requirement for lean deposition has two different phases: an energy dependent phase and a protein dependent phase. In the energy dependent phase, feed intake is the limiting factor because the voluntary feed intake is below the pigs’ growth potential. On the other hand, in the protein dependent phase, feed intake is not a limiting factor because the voluntary feed intake is above the pigs’ requirement for protein deposition (Dunkin et al., 1986). Any consumption beyond that required for maximal protein deposition results in increased fat deposition (Campbell et al., 1988). Whether a pig consumes feed beyond that required for maximal protein deposition depends on several factors, including the pigs’ genetic potential, energy density of the diet, and environmental constraints (Ex. heat, space allowance, feeder capacity and adjustment). In general, modern genetics housed under field conditions remain in an energy dependent stage of growth to much heavier body weights than older genetics. Thus, pigs can be full fed to much heavier weights than in the past without depositing excess backfat.
During the energy dependent phase of growth, diets should be formulated on a lysine:energy ratio as an increase in feed intake will increase energy consumption and the requirement of amino acids to support the extra protein deposition that can be accomplished with the extra energy. In the protein dependent phase of growth, when pigs are consuming more energy than required for their maximal protein deposition, diets should be formulated to meet the grams per day requirement. Thus, any increase in consumption can be accompanied by a reduction in dietary amino acid levels as the pig will not further increase protein deposition with the extra energy.
It is again important to note that the point at which pigs’ transition from the energy to protein dependent phase of growth is highly dependent on genotype and gender. Boars will rarely eat enough feed prior to market weights to maximize protein deposition. Similarly, gilts of many genotypes will be in the energy dependent phase of growth to market weights under most field conditions. Conversely, physical-castrated or immunologically-castrated barrows will often have a daily energy intake beyond their energy requirements for maximum protein deposition in the later finishing phases.
Dietary amino acids. Feeding diets below the amino acid requirement will decrease protein deposition and increase fat deposition (Main et al., 2008). Dietary amino acids fed in the late finishing period have the greatest impact on carcass lean content. In general, deficiencies of amino acids that do not have a major impact on feed intake (ex. lysine, methionine, threonine) will result in greater increases in carcass fat content than diets deficient in amino acids that have a greater impact on feed intake when below the requirement (ex. tryptophan, valine, isoleucine).
Nutrient specifications presented at the end of this manual are for lean growth optimization for market gilts and barrows, respectively. Performance was determined under commercial condition. Lysine specifications are presented as grams per Mcal of NRC NE and ME. There are typically two approaches to feed pens of pigs with both gilts and barrows: 1) use an average SID Lys requirement between gilts and barrows, or 2) use the SID Lys requirement for gilts. An example of how to calculate the percent SID lysine level of a diet is provided after each table. When formulating diets of variable energy levels, one should follow the SID lysine:calorie ratio that is provided in the tables. Actual dietary energy levels require a number of considerations that are specific to market and environment (Usry et al., 1997). This was also discussed in the introductory chapters of this manual.
To help prevent vices and to help realize the expected performance, the minimum nutrient specs below should be followed. Typically, nutritional stimulants for vices can be when amino acids, sodium and/or phosphorus levels are not adequate. Feed outages and feed restrictions can also be risk factors for vices. Other environmental conditions can cause vices as discussed in the PIC Wean to Finish Manual at http://na.picgenus.com/resources.aspx