Mineral nutrition of hyperprolific sows
W H Clo. Clo Consultancy, Wokingham, UK RG41 2 RS: e-mail:
I NTRODUCTION
One of the major achievements in pig production over the last few decades has been the improvement in sow reproductive performance and in veral countries it is not uncommon for sows to wean 25-30 piglets per year. The achievements have been brought about by a better understanding of the biology of the pig, including the nutrient requirements of the sow and the provision of feeding strategies to meet the needs. This paper will discuss the mineral nutrition of the sow, with special focus on the trace minerals.
M INERAL R EQUIREMENTS
Compared with the requirements for energy and amino acids, tho for minerals, and indeed vitamins, are poorly defined despite their importance to overall herd health and productivity. Requirements for minerals are hard to establish and most estimates are bad on the minimum level required to overcome a deficiency and not necessarily to optimi productivity, or indeed enhance immunity. It is fo
r this reason that industry levels of inclusion for sows are veral times greater than tho published requirements (Table 1) and recent studies have shown that at the higher levels of minerals reproductive performance may be impaired (Mahan and Peters, 2006).
Table 1. Recent estimates of trace mineral requirements of breeding sows, compared with the levels currently ud in practice (mg/kg)
NRC (1998) BSAS (2003) GfE (2006) Industry*
Mineral
Iron 80 80 80 - 90 80 - 150
Zinc 50 80 50 80 - 125
Copper 5 6 8 - 10 6 - 20 Mangane 20 20 20 - 25 40 - 60
Selenium 0.15 0.20 - 0.25 0.15 - 0.20 0.2 - 0.4道之道
Iodine 0.14 0.20 0.6 0.5-1.0
Most of the work carried out to establish mineral requirements, and trace minerals in particular, has been carried out pre 1980, and may not therefore be appropriate to the modern hyper-prolific sow. Indeed, for veral micro-minerals there is an extreme lack of information and Table 2 shows the number of citations on which the various NRC recommendations for breeding sows have been made. Some estimates for sows do not have a single cited study, or are bad on very few studies. Thus, the mineral requirements of sows are poorly defined and it is known that the body stores of both macro- and micro-minerals become depleted with advancing parity, and the higher the level of productivity, the greater the degree of depletion (Mahan and Newton, 1995).
Table 2. No. of references cited for trace minerals in NRC requirements for breeding sows
Total 1950 – 1970’s 1980’s 1990’s
Iron 10 7 3 -
Zinc 5 3 2 -
Copper 4 1 1 2
Mangane 7 4 2 1
Selenium 14 9 2 3
Iodine 0 0 0 0
(Lindemann and Kim, 2006)
C ONSEQUENCES OF INADEQUATE MINERAL SUPPLY
If dietary mineral supply is inadequate, then performance is likely to be affected and mobilisation from body tissues and skeletal structures occurs in an attempt to meet metabolic needs. This has been elegantly demonstrated by the work of Mahan and Newton (1995), which showed that the body mineral content of sows at Memorias del X Congreso Nacional de Producción Porcina, Mendoza, Argentina, 2010135
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the end of their third parity was considerably lower than that of non-bred litter sisters of similar age when fed diets of similar mineral content. In addition, the higher the level of productivity, that is litter weaning weight at 21 days of age, the greater the degree of depletion of minerals from the body.
Figure 1. Mineral loss (%) in sows after 3 parities relative to non-gravid sows (Mahan and Newton,
1995)
Mineral requirements are bad on a per kg of feed basis and take no account of the body weight of
the animal, its level of production, changing metabolic needs during both gestation and lactation or indeed parity. Richards (1999) has shown that already in late gestation, the sow has to rely on her liver iron rerves to meet foetal demands and this depletion of minerals from the body is further exacerbated during lactation. This continuous drain on body rerves results in reduced mineral status, as shown by Damgaard Pouln (1993).
Comparison of the daily mineral intake of a 1st parity sow with that of a mature sow in its 3rd or 4th parity, shows that there is a reduction in mineral intake of between 15 and 23%, bad on a body weight or metabolic body weight basis, respectively (Table 3). This may help to explain why the average sow lifetime in many countries is only 3–4 parities instead of the anticipated 5–6 parities.
Table 3. Trace mineral intake in relation to body weight and parity
Parity 1 (160 kg)
Intake 2 Parity 3+ (240 kg)
Intake 3
Difference 4 Recom-mended 1
per kg diet mg/day mg/kg BW mg/kg 0.75
mg/d mg/kg BW mg/kg 0.75
(1) (2) Fe (mg) 100 272 1.70 6.04 312 1.30 5.11 23 15 Zn (mg) 100 272 1.70 6.04 312 1.30 5.11 23 15 Cu (mg) 15 41 0.25 0.91 47 0.19 0.77 23 15 Mn (mg) 40 108 0.68 2.40 125 0.52 2.05 23 15 Se (mg) 0.25 0.68 0.0043 0.015 0.78 0.0033
0.0125
23
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学党章心得体会1
) BPEX: 2004 2
) Feed 2.3 kg/day in gestation and 5.0 kg/day over a 21 day lactation 3
) Feed 2.6 kg/day in gestation and 6.0 kg/day over a 21 day lactation 4
华宜大厦) (1) per kg BW (2) per kg 0.75
The most demanding period for minerals is during late gestation and lactation. For example, during the last 2 weeks of gestation some 50% of total minerals retained in developing foetal tissue were deposited (Mahan, 2007). Studies of foetal development have shown that a litter of 12 piglets requires approximately 73 and 44 g of Ca and P, respectively, during the last 2 weeks of gestation. Becau of this large requirement it is likely that bone demineralisation occurs with a possible weakening of the skeleton during late gestation and just prior to lactation when the demands are even higher. Similar traits have been en with the trace minerals.
The situation in lactation becomes even more exacerbated and studies have shown that sows suckling 11 compared with 8 piglets per litter need 85 and 68 g/day, respectively during the last 10 days of a 21-day lactation. The requirement for calcium was 19 g/day at the higher litter size and 13.3 g/day for the lower litter size. Thus, the demand for minerals increa with the stage of lactation as milk yield increas and as the demands increa with higher litter size. Similar traits have been shown with the trace minerals and it is interesting to note that the daily retention of iron (Fe) and copper (Cu) was greater in the first 11-day period: 20.3 and 11.5 g, respectively, than the last 10 days of a 21-day lactation, with 3.7 and 3.5 g, respectively (Mahan, 2007). The results suggest tha
t sows suckling large litters of piglets may be unable to meet the trace mineral needs of nursing piglets with
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the levels of minerals normally provided in the diet. Thus, the performance, health, immunity and welfare of the sow and her piglets are dramatically affected.
However, increasing the mineral content of the diet may not necessarily be the answer, as high levels of inorganic minerals have been shown to reduce reproductive performance. A better understanding of the mineral needs of the sow, as well as providing minerals in specialid form may be key to improving the reproductive performance, as well as to protect sow longevity.
垂柳怎么画F ORM OF MINERAL PROVISION
Customarily, inorganic salts - such as sulphates, carbonates, chlorides and oxides - are added to the diet to provide the correct levels to meet the animal’s need. The salts are then broken down in the digestive tract to form free ions and are absorbed. However, free ions are very reactive and can form complexes with other dietary molecules which are then difficult to absorb. The availability of the trace
mineral to the animal therefore varies considerably - and under extreme conditions may be unavailable for absorption -and so are of little benefit to the animal. Large quantities of undigested minerals are then excreted causing environmental pollution. It is also known that minerals in inorganic form interfere with each other, and excess of one can result in the reduced absorption of others.
For this reason there is growing interest in organic, that is proteinated or chelated minerals. In this form, the trace elements are chemically bound to a chelating agent or ligand, usually a mixture of amino acids or small peptides. This makes them more bio-available and bioactive and provides the animal with a metabolic advantage that often results in improved performance. It is only possible to chelate transition elements; other minerals, such as lenium and chromium can be provided in yeast form.
The respons to organic iron and lenium, or a combination of organic trace minerals, will rve well to illustrate the effects that organic minerals have on sow productivity.
S TUDIES ON ORGANIC IRON AND SELENIUM
Iron (Fe)
The piglet is born with limited iron rerves and needs supplemental iron after birth to prevent anaemia. Uteroferrin, an iron-binding protein, is the major mechanism by which the transfer of iron from the sow to the developing foetus occurs (Roberts et al, 1986). However, incread dietary inorganic iron has minimal effect on foetal iron uptake by the uteroferrin pathway. In contrast, organic iron has been shown to increa iron transfer across the placenta to the developing foetus (Ashmead and Graff, 1982).
A ries of commercial trials were therefore carried out in which sows were fed either a control diet containing 60-80 mg/kg inorganic iron or a test diet providing an additional 90 mg Fe/kg from an organic source (Bioplex Fe, Alltech Inc). The organic Fe was provided some 2-3 weeks before farrowing and throughout the 16-28 day lactation period.
The results showed that there was no difference in feed intake during lactation or the birth weight of the piglets. However, across all trials, the weaning weight of the piglets was incread from 6.17 (± 0.9) to 6.48 (± 0.9) kg (Table 4). Mortality of suckling piglets was reduced from 10.8% (range 9.6-13.0) to 6.8% (range 4.4-9.0). There was also a reduction in the proportion of lightweight piglets at weaning from 25.5 to 9.2% and an increa in the proportion of heavy-weight piglets from 45.2 to 55.3% (Table 4).
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Table 4. Organic Fe: Effects on sow and piglet performance (Clo and Taylor-Pickard, 2005)
Study/Country Sow feed intake
(kg/day) Piglet weaning wt (kg) Piglet mortality
俄国二月革命(%) % small piglets
% heavy piglets
UK (1) - -
11.0 -- 9.5 13 -- 5 55 -- 65 UK (2) - 6.47 -- 7.04 - - - Australia -
秋天蔬菜6.24 -- 6.51 - 21 -- 6 34 -- 41 Vietnam 4.76 -- 4.86 4.72 -- 4.93 13.0 -- 8.4 - - Chile
(90 ppm) 5.84 -- 6.06 9.6 -- 5.0 24 -- 17 46 -- 50
(150 ppm) 5.84 -- 6.49 9.6 -- 4.4 24 -- 9 46 -- 65 USA
4.59 -- 4.66
6.22 -- 6.22
23.1 -- 13.4*
- - The results suggest that piglets from sows fed additional organic Fe had an improved neo-natal Fe status, possibly through an incread placental transfer of uteroferrin. This makes for a more active and stronger piglet at birth, with greater viability and suckling stimulus. It is hypothesid that colostrum and milk intake is incread, resulting in reduced pre-weaning mortality and enhanced growth rate. Weaning weight is therefore incread and this has a lasting effect on subquent growth rate and development of the pig through to slaughter. Selenium (Se)
Although lenium is prent in plants and grain as organic Se, it has customarily been added to the
diet in inorganic form, and especially as sodium lenite. Despite this, lenium deficiency is prevalent worldwide. The problem is especially noted in piglets born to older, highly prolific sows. This may be related to the depletion of the sow’s trace mineral rerves with time. Mahan (1995) found that milk Se declined markedly after the 2nd parity in sows that had been reared and maintained on diets containing 0.3 ppm Se from sodium lenite (Figure 2). Damgaard Pouln (1993) has shown that the Se concentration in the rum of newborn piglets from parity 3 and 4 sows was significantly reduced compared with tho from parity 1 and 2 sows. This indicates that inorganic sources of Se cannot meet the Se requirements of the modern sow, and it is interesting to note that increasing problems with sows appear from parity 3 onwards (stillborn piglets, culling rate, wean-oestrus interval, etc.).
Figure 2. The effect of parity on the Se status of sows and piglets when fed sodium lenite
This has prompted the u of organic lenium from lenium yeast where the major source of Se is leno-methionine. The leno-aminoacid is better retained by the animal and results in higher levels in the body, with heightened immune status and incread productivity.
Compared to sodium lenite, the addition Se yeast to the diet of the sow during gestation and lactat
ion enhanced both the placental and mammary transfer of Se. Thus, the Se content of the piglet at birth and the colostrum and
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milk Se content are incread Mahan (2000) and Yoon and McMillan (2006). Mahan and Peters (2004) further noted that only dietary organic Se is effectively transferred to colostrum and milk. Feeding the sow organic Se improves the Se Status of the young piglet at a very critical period when
Se deficiency is most likely. The immune status of the piglet is enhanced, pre-weaning mortality is reduced and piglet performance improved. The number of stillborn piglets at parturition is also reduced. The milk Se content from sows fed Se yeast is maintained independent of parity, whereas it decreas with parity when they are fed similar levels of sodium lenite.
Figure 3. The effect of lenium level and source on colostrum and milk Se content
As a conquence of the higher Se status, an improvement in sow productivity has been reported in
veral studies when Se yeast (Sel-Plex™) was fed, compared with sodium lenite (Figure 4). Pre-weaning mortality was reduced by 20% from 14.5 6o 11.6%. As a conquence tho sows fed the Se yeast weaned 0.27 more piglets per litter compared to tho fed sodium lenite. Indeed, the return on investment, or ROI, when using Se yeast is calculated as 5:1, which is a very cost-effective respon.
Figure 4. The pre-weaning mortality of piglets from sows fed Se yeast (Sel-Plex™) or sodium lenite (Taylor Pickard and Clo, 2010)
(%)
12345678Mean
Trial No.
Sodium Selenite Se yeast
Shipp et al. (2008), also reported that the weaning weight of piglets from sows fed 0.3 ppm Se from Se yeast was 0.48 kg heavier than that of piglets fed 0.3 ppm Se from sodium lenite at similar age at weaning. Similarly, when piglets weaned from sow fed either Sodium lenite or Se Yeast were fed either Sodium lenite or Se yeast at 0.3 ppm Se in their diets in the 4-week period post weaning, mortality was reduced from 6.0 to 2.8%. This reduction in mortality, together with the higher litter size at weaning, results in an extra 1.1 pigs sold per sow per year (assuming 2.3 litters per sow per year).
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冬天英文Table 6. Effect of Se source on piglet mortality post weaning (Lampe et al. 2005) Sow diet Sodium Selenite (Na Se) Selenium Yeast (Se yeast)
/ \ / \ Piglet diet Na Se Se yeast
Na Se Se yeast
| | | | Mortality (%) 6.0
4.8
3.6
2.8
The studies demonstrate the superiority of providing Se in Se yeast rather than the inorganic form, such as sodium lenite.
鸡黍之交的故事T RIALS ON COMBINATION OF MINERALS
Different trace minerals impact at different periods of the reproductive life of the sow and it is likely th
at the greatest impact on sow productivity will be from combinations of minerals (Figure 5). Figure 5. Role of minerals in sow reproduction (Clo, 1999)
Insulin
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With this in mind, Feh and Clo (2000) supplemented the diet of sows with a special combination of organic minerals (Sow-Pak™: Se, Fe, Zn, Cu, Mn and Cr, Alltech Inc) and reported an extra 0.5 piglets weaned per litter for sows weaning 26.5 piglets per sow per year. Sow longevity was also incread as illustrated in Figure 6. The proportion of the sows fed Sow-Pak™ was maintained at 50-57% through parities 4 to 8, relative to 100% in parity 1, whereas for the control sows, it decread from 52% in parity 4 to approximately 20% in parity 6.
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