REARING GILTS AND FEEDING RECOMMENDATIONS OF A SOW DURING PREGNANCY AND LACTATION.

Introduction. 

In my top-selling video “Raising gilts and Suitable porkers”, I highlighted the major drivers of a profitable piggery enterprise. These were breed, management, and nutrition. Among these, management influences almost 70% of your farm’s success, however, the three move concurrently. The importance of nutrition in the profitability of animal production is well recognized. With the current increase in the demand for pork and pigs’ products, it is important to start thinking in the direction of increasing the farm’s productivity. Farmers need to devise means of shortening the time their pork hits the market. Moreover, the productivity of the sows in terms of litter size, farrowing index, longevity, among others are areas of utmost concern. Despite the importance of breed and management, it is inevitable to ignore nutrition if we’re to achieve the above targets. This article, therefore, intends to examine the importance of good feed in gilt development and sow’s reproductive performance. 

Highlights: 

The goals of feeding a gilt:

 • Sufficient mineral stores and well-developed strong bone structure. 

 • Optimal muscle development. 

 • Well-developed reproductive organs. 

 • Optimal backfat thickness and   

 • Adequate growth rate. 

The goals of feeding a sow: 

• Optimal Body Condition Score (BCS). 

 • High milk production. 

 • More weaned piglets/ year and 

 • Longevity. 

FEEDING OF GILTS: 

Gilt development and management begin in the early stages of a gilt’s life and ends when the gilt completes her first lactation. To meet the gilt targets at first breeding, PIC recommends ad libitum feeding from birth to the first breeding. Koudijs on the other hand recommends ad-lib feeding till week 14 and then restricting feed from 15 to 25 weeks. From week 26 to breeding at 31 weeks, flushing should be done. The goal is to attain the breeding targets at first breeding which were discussed in the previous article. It should be noted that the gilt rearing formula is different from the finisher diet. Gilts' diets have more calcium and phosphorus as compared to their counterparts. The mixing proportions are shown in Table 1 

FEEDING OF A SOW DURING GESTATION 

The feed requirements can be divided into three phases: Early gestation (1-28d), Mid-gestation (29-84d), and Late gestation (85-114d) 

I. Early gestation 

Gilt's nutritional demands are different from those of a sow and gilts are always given less feed as compared to sows throughout gestation. Excessive feed intake during early gestation reduces the chances of embryo survival. This results in smaller litter size. Research shows that progesterone hormone is essential during embryo implantation. Moreover, it influences the secretion of uteroferrin and retinol-binding proteins which enhance embryo survival. Therefore, lower circulating levels especially in gilts during this phase might lead to embryo mortality. The feeding recommendations are shown in Table 1. Sows, on the other hand, need more feed during this phase since they have lost a considerable amount of weight during lactation. It is important to note that sows are fed according to their body condition score. Studies show that second litter size (SLS) is affected by absolute body reserves at weaning and by their mobilization during lactation indicating the importance of achieving an adequate body condition at parturition and of optimizing the feed intake in lactating primiparous sows. An additional amount of feed helps the sows to rebuild their body reserves as poor nutrition may negatively affect the number of eggs available for fertilization. Moreover, poorly conditioned sows might have long weaning to estrus intervals. So, the extra feed will improve the sow's reproductive performance. The feeding schedule is shown in Table 1.

 II. Mid gestation 

During this phase, there is a considerable increase in energy requirement for maintenance and maternal body gain. The body condition score of 3 is ideal throughout gestation. Therefore, feeding during this phase should be to maintain or to meet the nutrient demand to meet the target. Much as mammary and fetal development is still limited in this phase, proper feeding would help in the development of both primary and secondary muscle fibres. These greatly influence the piglet's birth weight and consequently, the post-weaning performance. The feeding recommendations are shown in Table 1. 

III. Late gestation 

This is the period of maximum foetal and mammary gland development and, therefore, a significant increase in the nutritional need of the sow. It is therefore a common practice to feed an extra 0.4 to 0.5 Kg to meet the increasing nutritional demand. 

Remarks 

• The feeding schedule depends on the body condition of the pig. 

Table 1. Gestation Feed Schedule.

Day	Skinny Sows	Normal Sows	Fat Sows	Gilts
0	3.3	2.8	2.5	2.2
30	3.3	2.8	2.5	2.2
35	2.9	2.6	2.4	2.5
80	2.9	2.6	2.4	2.5
85	3.2	3.2	3.2	2.9
112	3.2	3.2	3.2	2.9
Total	346.4	316.4	297.4	283.8

Table 2. The Sow Concentrate Formula.

Ingredient	Gilts (16-31 wks)	Gestation	Lactation
KSC22.5/17.5/15	17.50	15.00	22.50
Maize	62.50	60.00	62.50
Maize bran	20.00	25.00	15.00
Total	100.00	100.00	100.00

FEEDING DURING LACTATION.

The lactating sow needs energy and nutrients to maintain body tissues and support milk production while allowing for maternal growth. Adequate nutrient intake should minimize sow weight loss and enhance subsequent reproductive performance. Understanding the different factors that affect nutrient requirements and feed intake consequently helps in developing a successful lactating sow feeding program. Averagely, a sow consumes 5.7 Kg while a gilt consumes 4.9 Kg during lactation.

Feeding program/schedule.

Remarks:

·         Max feed gift sows: 2,0Kg + 0.5 Kg x no. piglets

Max feed gift gilts: 2,0Kg + 0.4 Kg x no. piglets 

 Table 3. Lactation Feed Schedule.

Day	Sows	Gilts
-5	2.8	2.6
-3	2.6	2.4
-1	2.6	2.4
* farrowing	2.2	2.1
1	2.2	2.1
2	2.6	2.5
3	3.2	3.0
4	3.8	3.5
5	4.4	4.0
6	5.2	4.5
7	5.8	5.0
8	5.8	5.0
9	6.4	5.5
10	6.4	5.5
11 to 28	7.0	6.0
Average	5.7	4.9
Total	182	158