Impact of energy intake and pregnancy status on rate and efficiency of gain and backfat changes of sows postweaning

A collaborative study was conducted to evaluate factors related to determining optimal feeding and management programs for increasing net returns from marketing cull sows. A total of 269 multiparous sows averaging 192 kg of body weight were weaned, moved to individual gestation crates, and assigned to one of eight treatment combinations in a 2 x 2 x 2 factorial arrangement for a 42-d postweaning feeding experiment. Factors included limited (L) (1.8 kg/sow/d) or ad libitum (AL) access to feed during wk 1 postweaning, a corn-soybean meal (corn) or barley-sunflower meal (barley) diet, and pregnant or nonpregnant status. All sows were provided ad libitum access to feed from wk 2 to 6 postweaning. Gain and feed intake (FI) data were collected weekly for each sow and used to calculate gain:feed (G/F). Ultrasonic backfat (BF) data were collected on d 0, 21, and 42 postweaning. Sows on the AL treatment had greater FI (P < 0.05) but similar gain (P = 0.80) for the 42-d postweaning period compared to sows on the L treatment. Most of this response was due to lower sow body weight loss during wk 1 postweaning (P < 0.01) when sows were provided AL (-7.2 kg) vs L (-13.2 kg) access to feed. Sows fed the corn diet had higher gain (P < 0.01), improved G/F (P < 0.01), and increased BF (P < 0.01) over the 42-d feeding period than sows fed barley. The corn diet resulted in less sow BW loss (P < 0.01) during wk 1 (-8.8 kg) than the barley diet (-11.6 kg). Pregnant sows had higher gain, FI, G/ F, and BF (P < 0.01) than nonpregnant sows over the 42-d feeding period. Most of this advantage occurred during wk 4 postweaning when FI and gain of nonpregnant sows was lower (P < 0.01) than for pregnant sows. An economic analysis indicated that, when cull sow prices are relatively high and feed prices are moderate to low, maintaining and managing cull sows for an additional 6 wk postweaning may be economically advantageous compared to 0 or 3 wk. Pregnant sows fed the corn diet produced the greatest economic return. These results suggest that mating sows as they return to estrus postweaning and providing ad libitum access to a corn-soybean meal diet improves growth performance and feed efficiency, and may thereby provide increased returns when marketing cull sows.     

An increased feed intake during early pregnancy improves sow body weight recovery and increases litter size in young sows

This study evaluated the effect of feeding level and protein content in feed in first- and second-parity sows during the first month of gestation on sow BW recovery, farrowing rate, and litter size during the first month of gestation. From d 3 to 32 after the first insemination, sows were fed either 2.5 kg/d of a standard gestation diet (control, n = 49), 3.25 kg/d (+30%) of a standard gestation diet (plus feed, n = 47), or 2.5 kg/d of a gestation diet with 30% greater ileal digestible AA (plus protein, n = 49). Feed intake during the experimental period was 29% greater for sows in the plus feed group compared with those in the control and plus protein groups (93 vs. 72 kg, P < 0.05). Sows in the plus feed group gained 10 kg more BW during the experimental period compared with those in the control and plus protein groups (24.2 ± 1.2 vs. 15.5 ± 1.2 and 16.9 ± 1.2 kg, respectively, P < 0.001). Backfat gain and loin muscle depth gain were not affected by treatment (P = 0.56 and P = 0.37, respectively). Farrowing rate was smaller, although not significantly, for sows in the plus feed group compared with those in the control and plus protein groups (76.6% vs. 89.8 and 89.8%, respectively, P = 0.16). Litter size, however, was larger for sows in the plus feed group (15.2 ± 0.5 total born) compared with those in the control and plus protein groups (13.2 ± 0.4 and 13.6 ± 0.4 total born, respectively, P = 0.006). Piglet birth weight was not different among treatments (P = 0.65). For both first- and second-parity sows, the plus feed treatment showed similar effects on BW gain, farrowing rate, and litter size. In conclusion, an increased feed intake (+30%) during the first month of gestation improved sow BW recovery and increased litter size, but did not significantly affect farrowing rate in the subsequent parity. Feeding a 30% greater level of ileal digestible AA during the same period did not improve sow recovery or reproductive performance in the subsequent parity.     

Increased maternal nutrition of sows has no beneficial effects on muscle fiber number or postnatal growth and has no impact on the meat quality of the offspring

The objective of this study was to examine how increased feed intake of the sow during early to mid-gestation affects sow performance and the muscle fiber number, performance, and technological meat quality of the offspring. Thirty-nine pregnant sows (Landrace x Large White sows mated to Landrace or Large White boars) in their fourth parity were assigned to one of three treatments: 1) the sows were either fed restrictively (control = 15 MJ of NE/d from d 1 to 90, then 24 MJ of NE/d from d 91 to 112, and again 15 MJ of NE/d from d 113 to 115 of gestation); 2) fed ad libitum from d 25 to 50 (A25-50); or 3) ad libitum from d 25 to 70 (A25-70) and as control in the remaining periods. The offspring were weaned at 4 wk of age and had free access to feed from 2 wk of age until slaughter. They were slaughtered litterwise at an average body weight of 104 +/- 14 kg. Estimates for total, primary (P-), and secondary (S-) muscle fiber number; muscle fiber area; and DNA and RNA content were analyzed in semitendinosus muscle (ST) samples from the heaviest, middle, and lightest weight (LW) pigs of each sex within litter selected at slaughter. Technological meat quality traits (pH at 24 h postmortem, drip loss, Minolta color, and pigment) were analyzed in longissimus dorsi muscle. Fiber number, fiber area, and concentrations and content of DNA and RNA of the offspring were not significantly affected by increased maternal nutrition. The ST muscle weight was lower in offspring from A25-50 than control sows (P = 0.019). Average daily gain, carcass weight, and the muscle deposition rate also were numerically lower for A25-50 than control and A25-70 pigs. An interaction between treatment and pig weight was found for muscle deposition rate (P = 0.006), in that LW pigs from treatment A25-50 had a lower deposition rate than LW pigs from control. We found no effect of treatment on the meat quality traits in the offspring. Also, barrows had a higher (P < 0.05) number of P-fibers, higher daily gain, and carcass weight than female pigs. No differences were found on any meat quality traits between sexes. Thus, ad libitum feeding of pregnant sows from d 25 to 50 or d 25 to 70 of gestation did not have any beneficial effect on muscle fiber number and area in the offspring. It seems that maternal ad libitum feeding from d 25 to 50 in gestation had a negative effect on postnatal muscle growth, with especially the LW pigs being affected.     

Space allowance for dry, pregnant sows in pens: body condition, skin lesions, and performance

Different floor space allowances for dry, pregnant sows in pens were evaluated to determine the impacts of space on sow performance, productivity, and body lesions during 2 consecutive farrowings. Treatment groups of 5 sows/pen were assigned to 1.4, 2.3, or 3.3 m(2) of floor space/sow or of 5 sows in individual stalls (1.34 m(2)). The experiment consisted of 6 replications (blocks 1 to 6), and within each block measurements were recorded for 2 consecutive pregnancies and farrowings. A total of 152 sows were measured at 1 farrowing, and 65 of those sows were measured at the successive farrowing (n = 217 records). Performance traits were BCS, BW, backfat (BF), days until rebred, and proportion culled. Litter traits were number of piglets born alive, male:female ratio, and proportions of stillborn, mummified, or dead piglets after birth. Litter performance measures were mean piglet BW and gain and litter BW. Lesion scores were assessed for several body regions. There were treatment and parity effects and interactions for several traits. An interaction of space treatment and parity occurred for sow mean BW, d-110 BW, BF, litter size, and litter and piglet BW and gain, with most effects in parity 2, 3, and 4 sows. Space affected sow mean (P < 0.001) and d-110 BW (P < 0.05) and mean BF and adjusted BF (P < 0.001); sows in pens at 相似文献   

Comparison of three methods of feeding sows in gestation and the subsequent effects on lactation performance

A total of 684 sows from breeding groups over 6 wk was used to compare three methods of feeding during gestation on gestation and lactation performance. Control gilts and sows were fed according to body condition based on a scale of 1 to 5 (1 = thin, 5 = fat). Sows were visually assessed for body condition at breeding and were assigned a daily feed allowance to achieve a BCS of 3 at farrowing. Treatment 2 used feeding levels based on backfat thickness (measured between d 0 and 5 after breeding) and weight at weaning for sows or service for gilts. Feed allowance was calculated to achieve a target backfat of 19 mm at farrowing, and remained constant from d 0 to 101 of gestation. Feed allowances were based on modeled calculations of energy and nutrient requirements to achieve target sow maternal weight and backfat gains. Treatment 3 was identical to Treatment 2, except that feeding pattern was altered for thin sows and gilts (<15 mm at service) in an attempt to reach 19 mm by d 36 of gestation. Sows were weighed at the previous weaning, and gilts were weighed at service, with both weighed again between d 112 and 114 of gestation. Backfat was measured between d 0 and 5, and again between d 108 and 113 of gestation. At farrowing, sows on Treatments 2 and 3 had 19 and 19.1 mm of backfat, respectively, whereas control sows tended to have greater (P < 0.07) backfat (20 mm). On average, sows targeted to gain 6 to 9 mm of backfat failed to reach target gains regardless of feeding method. Feeding sows in gestation based on backfat (Treatments 2 and 3) resulted in a numerically higher proportion of sows in the target backfat range of 17 to 21 mm (40.2, 53.3, and 52.6% for control and Treatments 2 and 3, respectively) at farrowing and a numerically lower percentage of fat sows (>21 mm), but no difference in the percentage of thin sows (<17 mm) compared with feeding based on body condition. In conjunction with this observation, sows fed based on BCS were fed higher (P < 0.05) feeding levels in gestation than were sows fed based on backfat depth. Gestation feeding method had no effect on performance during lactation. Feed intake in lactation was lower (P < 0.05) for high backfat sows (>21 mm) at farrowing compared with sows with <21 mm. The high proportion of sows in the optimal backfat category demonstrates that feeding based on backfat and BW has potential for facilitating more precise feeding during gestation.     

The addition of ground wheat straw as a fiber source in the gestation diet of sows and the effect on sow and litter performance for three successive parities

A regional experiment was conducted at 8 experiment stations, with a total of 320 sows initially, to evaluate the efficacy of adding 13.35% ground wheat straw to a corn-soybean meal gestation diet for 3 successive gestation-lactation (reproductive) cycles compared with sows fed a control diet without straw. A total of 708 litters were farrowed over 3 reproductive cycles. The basal gestation diet intake averaged 1.95 kg daily for both treatments, plus 0.30 kg of straw daily for sows fed the diet containing ground wheat straw (total intake of 2.25 kg/d). During lactation, all sows on both gestation treatments were fed ad libitum the standard lactation diet used at each station. Response criteria were sow farrowing and rebreeding percentages, culling factors and culling rate, weaning-to-estrus interval, sow BW and backfat measurements at several time points, and litter size and total litter weight at birth and weaning. Averaged over 3 reproductive cycles, sows fed the diet containing wheat straw farrowed and weaned 0.51 more pigs per litter (P 相似文献   

Effect of energy and lysine intake in gestation on sow performance

Nutrient intake during gestation has an impact on gestation parameters and subsequent lactation performance. The objectives of this experiment were to determine the impact of feeding two levels of amino acids in gestation on sow BW changes in gestation and lactation, and litter size, and to evaluate a factorial method for determining daily energy requirements. At mating, 419 sows (Camborough 15; Pig Improvement Canada, Acme, AB) were assigned randomly within Parities 1, 2 or 3+ to a gestation diet containing either 0.44% (low lysine) or 0.55% (high lysine) total lysine and 3,100 kcal DE/kg; other indispensable amino acids were adjusted to lysine based on ideal protein ratios. Feed allowance in gestation was determined factorially using estimated DE requirements for maintenance, maternal gain, and conceptus growth. Sows were allowed free access to the lactation diet. Gestation BW gain from d 0 to 110 was affected by parity (61.2, 60.0, and 42.3 kg for Parity 1, 2, and 3+, respectively; P < 0.05) but not (P > 0.10) by gestation lysine level. Sow BW changes from d 0 of lactation to weaning were affected by parity (0.5, 6.8, and 5.8 kg for Parity 1, 2, and 3+, respectively; P < 0.01) and gestation BW gain (P < 0.01), but not by gestation lysine level (5.0 vs 3.8 kg for low and high lysine, respectively; P > 0.10). Total piglets born was affected by parity (11.5, 12.1, and 12.5, for Parity 1, 2, and 3+, respectively; P < 0.01) and increased with increasing sow BW gain (P < 0.05). Total piglets born alive (mean = 11.2) was increased with increasing sow BW gain (P < 0.05). Total litter weight born alive was affected by parity (15.9, 18.6, and 19.4 kg for Parities 1, 2, and 3+, respectively; P < 0.01) and gestation BW gain (P < 0.05). The model used to determine daily energy intake requirements resulted in an average BW gain of 10.6 kg above the targets set by the model. Total lysine intakes greater than 10.6 g/d in gestation did not improve sow productivity. Setting target weight gains in gestation and feeding to meet these targets may not always provide predictable results due to a number of factors that affect the energy requirement in the sow.     

Increased sow nutrition during midgestation affects muscle fiber development and meat quality, with no consequences on growth performance

Pregnant sow nutrition has potential effects on the muscle fiber development of progeny in utero. A total of 199 Landrace x Large White sows from parities 0 to 6 and their offspring were used to evaluate the effects of increasing the feeding amount during midpregnancy on the muscle tissue, growth performance, and meat quality of the progeny. The experiment was divided into 2 study replicates, and in each replicate, sows were assigned to 1 of the 2 treatments: 1) sows in the control group (C sows) were fed 2.5 to 3.0 kg/d (feed: 12.1 MJ of ME/kg and 0.62% lysine) throughout gestation; and 2) sows in the high group (H sows) received an extra feed allowance of 1.5 kg/d for gilts and 2.0 kg/d for multiparous sows above the C amount from d 45 to 85 of gestation (period of secondary muscle fiber formation). Sow backfat was recorded on d 40 and 85 of gestation. Sow performance (litter size and piglet BW) at farrowing and on d 18 of lactation was measured. At weaning, pigs were divided into 5 BW groups/treatment, and progeny growth performance was measured during the nursery (n = 958) and the growing-finishing (n = 636) periods. At slaughter, carcass and meat quality traits (lean content, main cut weight, pH, Minolta color, and drip loss) were recorded from the second lightest group at weaning (BW group 4; n = 90), and samples from the longissimus thoracis muscle were taken to study muscle fiber characteristics (n = 70). The extra nutrition from d 45 to 85 of gestation did not lead to differences in litter size or piglet BW at farrowing and on d 18 of lactation. Pigs born to H mothers had fewer muscle fibers and fewer estimated primary and secondary fibers than did pigs born to C mothers (P < 0.05). However, postnatal growth performance was not consistently affected by the maternal treatment. The smaller number of muscle fibers found in the H group of pigs was associated with fewer type IIB fibers (P < 0.05) with greater cross-sectional areas (P < 0.10), which might be related to the significantly greater meat pH at 24 h postmortem and the smaller L* (lightness) values recorded in the H group of pigs. Results from the present study confirm the existence of effects of maternal nutrition on fetal development, at least in terms of muscle tissue development and meat quality, although with no beneficial effects were found for the postnatal growth performance of the progeny.     

Impact of diet deprivation and subsequent over-allowance during prepuberty. Part 2. Effects on mammary gland development and lactation performance of sows

The impact of diet deprivation and subsequent over-allowance in prepubertal gilts on their mammary development and mammary gene expression at the end of gestation and their lactation performance over 2 parities was determined. Seventy-seven gilts were reared under a conventional (control, CTL; n = 41) or an experimental (treatment, TRT; n = 36) dietary regimen. The experimental regimen provided 70 (restriction diet, RES) and 115% (over-allowance diet, OVER) of the protein and DE contents provided by the CTL diet. Experimental diets were fed ad libitum starting at 27.7 ± 3.4 kg of BW as follows: 3 wk RES, 3 wk OVER, 4 wk RES, and 4 wk OVER. All gilts were bred, and 34 were slaughtered on d 110 of gestation (18 CTL and 16 TRT) to collect mammary tissue for compositional analyses and gene expression measurements. Remaining gilts (23 CTL and 20 TRT) were maintained for 2 parities, and litter performance data were obtained. Blood samples for hormonal and metabolite assays were obtained on d 110 of gestation from all sows slaughtered at that time and from 14 sows per treatment on d 2 and 17 of lactation in the first parity. Milk samples were obtained from these same sows on d 17 of lactation in both parities. There was a tendency for mammary parenchymal tissue to contain less protein in TRT than CTL sows (P < 0.10), and relative mRNA abundance of the signal transducer and activator of transduction 5B gene was increased in parenchyma from TRT sows (P < 0.05). Circulating prolactin (P < 0.05) and milk lactose concentrations (P < 0.01) were less, whereas milk protein content was greater (P < 0.05) in TRT sows than CTL sows on d 17 of lactation. Nevertheless, growth rate of suckling piglets over the first 2 parities was unaffected by treatment. In conclusion, the use of a diet deprivation and over-allowance regimen in the growing-finishing period did not have beneficial effects on mammary gene expression or on sow and piglet performance.     

Prenatal stress effects on pig development and response to weaning

Exposing a pregnant sow to stress has been shown to affect the resulting offspring. Our objective was to determine if rough handling of pregnant sows altered the physiology of her offspring and if these alterations were different from an experimentally induced model of prenatal stress. Sow treatments consisted of i.v. injections of ACTH (1 IU/kg of BW), exposure to rough handling for 10 min (Rough), or no treatment (Control) once a week during d 42 to 77 of gestation. To determine the plasma cortisol response to treatments, blood (5 mL) was collected from 30 sows after treatment administration. To conduct the prenatal stress study, a separate group of 56 sows was used in 1 of 4 replicates. At birth, production data were collected for each litter, including birth weight, number born, anogenital distance, and pig viability. At weaning, pigs were blocked by BW and sex, and placed in a nursery pen of 6 pigs, with 2 pigs from each treatment group. To assess the effect of treatments on cortisol, corticosteroid-binding globulin (CBG), and hematological cell profiles, blood was collected every other day for 10 d after weaning. Application of treatments caused plasma cortisol concentrations to be greatest in ACTH sows compared with Control sows (P < 0.001), with Rough sows having intermediate values (P = 0.07). Treatments did not affect the number of pigs born, number of stillborn, or pig viability (P > 0.40). The ratio of cortisol to CBG did not differ between treatments (P = 0.09). Hematological variables did not differ between treatments (P > 0.19). Pigs born to ACTH sows had a smaller anogenital distance compared with controls (P < 0.03), with pigs from Rough sows being intermediate. Our data indicate that swine exposed to prenatal stress (ACTH injection) can have alterations in sexual morphology without effects on growth or the immune cell populations measured in this study.     

Effects of a high-fiber diet and frequent feeding on behavior, reproductive performance, and nutrient digestibility in gestating sows

A study was conducted to determine the effects of feeding a corn-soybean meal (control) diet vs. a corn-soybean meal-40% soybean hulls (high fiber) diet, as well as the frequency of feeding (once vs. twice daily), on the welfare and performance of gestating sows. Two hundred thirty-nine mixed-parity sows were assigned to a 2 x 2 factorial arrangement of treatments. Sows fed once daily received their entire meal at 0730, whereas sows fed twice daily received one-half of their feed allotment at 0730 and the other half at 1430. The behavior of 68 focal sows (> or = 16 sows per treatment combination) was observed on d 1 postweaning, and on d 40 and d 80 of gestation. The percentage of time standing, lying, sitting, feeding, inactive, and performing stereotypic behaviors was determined. Saliva samples were collected to determine cortisol concentrations. Sow BW and backfat depth were determined on d 0, 40, and 80 of gestation, within 24 h of farrowing, and at weaning. An energy and nitrogen digestibility study was conducted using 36 sows assigned to each of the 4 treatment combinations. Over a 24-h period, the sows fed the high-fiber diet spent less time lying (P < 0.05) than the sows fed the control diet. The frequency of feeding did not affect sow behavior measured over a 24-h period. During mealtimes, sows fed the high-fiber diet spent more time feeding (P < 0.05) than sows fed the control diet. Feeding the high-fiber diet did not affect stereotypic behavior measured over 24 h or during mealtimes. Neither diet nor feeding frequency affected salivary cortisol concentration. Sows fed the high-fiber diet gained less BW and lost backfat (P < 0.05) during gestation compared with sows fed the control diet, whereas sows fed once daily gained less BW and lost backfat (P < 0.05) compared with sows fed twice daily. Sows fed the high-fiber diet had fewer pigs born (P < 0.05) compared with sows fed the control diet. Feeding frequency had no effect on size or weight gain of litters. Sows fed the high-fiber diet exhibited lower digestibility of DM, energy, and N (P < 0.05) compared with sows fed the control diet. Feeding a high-fiber diet utilizing soybean hulls or increasing feeding frequency did not enhance the welfare of sows by reducing stereotypic behaviors nor did it improve reproductive performance.     

Influence of Carnichrome on the energy balance of gestating sows

Twelve multiparous sows with an average initial weight of 182 kg were used in a randomized complete block design to determine the effects of feeding Carnichrome (50 mg of carnitine and 200 microg of chromium picolinate per kilogram of feed, as fed) on energy and nitrogen utilization in early, mid-, and late gestation. All sows were fed a diet with or without Carnichrome for the preceding 28-d lactation, the weaning-to-estrus period, and for the duration of gestation. Daily feeding allowances over pregnancy were based on calculated energy and nutrient requirements to achieve a target sow maternal weight gain of 20 kg and remained constant throughout gestation. Heat production (HP) and its partitioning (activity, thermic effect of feeding short term [TEFst], basal) were determined in early (wk 5 or 6), mid- (wk 9 or 10), and late (wk 14 or 15) pregnancy using indirect calorimetry. Net maternal weight gain and total number of fetuses averaged 21.6 kg and 16.4, respectively. Organic matter and energy digestibility for the Carnichrome diet was greater (P < 0.05), which resulted in greater DE and ME contents (0.6%, P < 0.05) compared with the control diet. The digestibility coefficient of energy in the current experiment for a typical corn and soybean meal diet (92%) was greater than that predicted from DE values of corn and soybean meal in feeding tables (88%). Carnichrome had no effect on total HP, energy retained as protein or lipid, and maternal energy retention in early, mid-, or late gestation. Heat production in late gestation increased linearly (4.0 kJ/[kg BW0.75 x d]) for each additional day from d 90 to 110, despite the reduction of ME intake per unit of BW0.75. Metabolizable energy requirement for maintenance was 405 kJ/(kg BW0.75 x d). On average, activity HP was 116 kJ/(kg BW0.75 x d), which was equivalent to 20% of ME intake; however, this value ranged from 11 to 37% between sows, which corresponds to duration of standing ranging from 210 to 490 min/d. Energy cost of standing activity averaged 0.30 kJ/(kg BW0.75 x min). In conclusion, Carnichrome had no effect on the components of heat production and maternal weight gain during gestation, although it improved energy and organic matter digestibility of the diet.     

Effects of L-carnitine fed during gestation and lactation on sow and litter performance

Multiparous sows (n = 307) were used to evaluate the effects of added dietary L-carnitine, 100 mg/d during gestation and 50 ppm during lactation, on sow and litter performance. Treatments were arranged as a 2 (gestation or lactation) x2 (with or without L-carnitine) factorial. Control sows were fed 1.81 kg/d of a gestation diet containing .65% total lysine. Treated sows were fed 1.59 kg/d of the control diet with a .23 kg/d topdressing of the control diet that provided 100 mg/d of added L-carnitine. Lactation diets were formulated to contain 1.0% total lysine with or without 50 ppm of added L-carnitine. Sows fed 100 mg/d of added L-carnitine had increased IGF-I concentration on d 60 (71.3 vs. 38.0 ng/mL, P<.01) and 90 of gestation (33.0 vs. 25.0 ng/mL, P = .04). Sows fed added L-carnitine had increased BW gain (55.3 vs 46.3 kg; P<.01) and last rib fat depth gain (2.6 vs. 1.6 mm; P = .04) during gestation. Feeding 100 mg/d of added L-carnitine in gestation increased both total litter (15.5 vs. 14.6 kg; P = .04) and pig (1.53 vs 1.49 kg; P<.01) birth weight. No differences were observed in pig birth weight variation. Added L-carnitine fed during gestation increased litter weaning weight (45.0 vs. 41.3 kg, P = .02); however, no effect of feeding L-carnitine during lactation was observed. No differences were observed in subsequent days to estrus or farrowing rate. Compared to the control diet, feeding added L-carnitine in either gestation, lactation, or both, increased (P<.05) the subsequent number of pigs born alive, but not total born. In conclusion, feeding L-carnitine throughout gestation increased sow body weight and last rib fat depth gain and increased litter weights at birth and weaning.     

Survival and postweaning performance of pigs from sows fed fat during late gestation and lactation

Sows were fed a control corn-soybean meal gestation diet to d 80 of gestation. One group of sows (n = 25) continued receiving the control diet until the end of lactation, whereas two groups were placed on other treatments. One group (n = 27) was fed a diet containing 5% added solid fat pellets from gestation d 80 through lactation, whereas another group (n = 25) was fed a diet with 10% added solid fat pellet from gestation d 100 through d 14 of lactation. Feed supply was 2.27 kg/d during gestation and to appetite during lactation. Pigs from sows fed the control diet or 5% solid fat pellet diet were weaned with an age range of 22 to 28 d and immediately allotted in a 2 x 3 factorially designed 4-wk feeding trial. Pigs from these two sow groups were fed diets 1) without fat, 2) with 4.5% choice white grease or 3) with 5% solid fat pellet. Sow weight loss, backfat change and pig weights were not different at weaning among treatments. Survival rates of all pigs to 21 d averaged 90% with no significant differences between treatments. Pigs from fat-fed sows had more (P less than .05) glycogen per gram of liver, 41% more total liver glycogen and 16% more serum glucose at birth. Weanling pigs from fat-fed sows grew slower (P less than .05) than pigs from control sows. Supplemental fat during gestation increased liver glycogen of pigs, which should help survival, but the feeding of fat throughout lactation had a negative effect on ADG during a 4-wk postweaning period.     

Lower birth weight and attenuated adrenocortical response to ACTH in offspring from sows that orally received cortisol during gestation

Prenatal stress is known to affect several offspring characteristics, but its effects depend among other factors on the period of gestation in which it is applied. In the present study, oral administration of hydrocortisone-acetate (HCA) was used to elevate cortisol concentrations in pregnant sows to levels also observed after psychological stress. HCA was administered during three different periods of gestation (115 days in pigs): period 1: 21-50 (P1, n = 10), period 2: 51-80 (P2, n = 10) and period 3: 81-110 (P3, n = 10) days after insemination. Control sows (n = 11) received vehicle from 21-110 days after insemination. When P1-, P2- and P3-sows did not receive HCA, they also received vehicle. During gestation, weekly saliva samples were taken from the sows to determine salivary cortisol concentrations. Treatment effects on sow, litter and piglet characteristics were determined. In addition, two female piglets per litter were subjected to an ACTH-challenge test at 6 weeks of age to determine the adrenocortical response to ACTH. Pigs were slaughtered at 6 months of age and slaughter weight, back fat thickness and percentage of lean meat were analysed. During the period of treatment with HCA, salivary cortisol concentrations were increased in P1-, P2- and P3-sows compared to control sows (P < 0.01). The total number of piglets born per litter did not differ among treatment groups (P > 0.30), but pooled HCA-litters had a higher percentage of live born piglets (P < 0.05) and fewer mummies than control litters (P < 0.05). Gestation length did not differ among treatment groups (P = 0.21), but did affect treatment effects on birth weight. Overall, HCA-piglets weighed less at birth, and remained lighter until weaning (P < 0.05). The salivary cortisol concentrations after i.m. injection of ACTH (2.5 IU/kg) were lower in P1- and P3-piglets compared to control piglets. At slaughter, HCA-treatment indirectly decreased lean meat percentage and increased back fat thickness. In conclusion, elevated peripheral cortisol concentrations in pregnant sows affect both litter characteristics and piglet physiology, the latter depending on the period of gestation during which concentrations were elevated. Underlying mechanisms require further investigation.     

Dietary fiber for pregnant sows: influence on sow physiology and performance during lactation

This study was conducted to investigate the effects of feeding sows a bulky diet during gestation on their physiological and metabolic adaptations during the peripartum period, and to determine how these effects may relate to sow and piglet performances. From d 26 of gestation until farrowing, gilts were fed diets that contained 2.8 or 11.0% crude fiber (control and high-fiber diets, respectively, n = 9/group). Daily feed allowance provided the same amount of DE daily (33 MJ of DE/d). Throughout lactation, sows were allowed to consume a standard lactating sow diet ad libitum. Litters were standardized to 12 piglets beyond 48 h after birth. On d 105 of gestation, a jugular catheter was surgically implanted. Preprandial blood samples were collected from d 109 of gestation to the day after farrowing and on d 4, 18, and 26 of lactation. Meal tests and glucose tolerance tests were performed on d 109 of gestation and d 4 and 18 of lactation. During gestation, BW and backfat gain did not differ between treatment groups. During lactation, sows fed the high-fiber diet ate an average of 0.94 kg/d more than control sows (P < 0.02). Piglets born from sows fed the high-fiber diet grew faster than piglets from control sows (P = 0.03). Body weight and backfat losses did not differ between the 2 treatment groups. Sows fed the high-fiber diet during gestation had lesser concentrations of leptin before farrowing than control sows (P < 0.01). Leptin concentrations were negatively correlated with feed intake during lactation (P < 0.05). The prepartal increase in prolactin concentrations tended to be greater in sows fed the high-fiber diet than in control sows (P < 0.1). Preprandial concentrations of glucose, NEFA, lactate, and IGF-I fluctuated over time without significant treatment effect. Glucose half-life was shorter in late gestation than during both stages of lactation, but did not differ between sows in the 2 groups. In late gestation, the postprandial increases in glucose and insulin were delayed, and smaller, after a high-fiber meal than after a control meal. During lactation, glucose and insulin profiles after a standard meal did not differ between sows from treatment groups. In conclusion, the greater appetite of lactating sows fed a high-fiber diet during gestation does not seem related to changes in glucose and insulin metabolism and may be partly due to decreased secretion of leptin. The greater feed consumption was accompanied by a faster growth rate of piglets without sparing effect on maternal body reserves.     

Performance and individual feed intake characteristics of group-housed sows fed a nonstarch polysaccharides diet ad libitum during gestation over three parities

The objective of this experiment was to study the effects of feeding group-housed gestating sows a diet with a high level of fermentable nonstarch polysaccharides (NSP; approximately 45% sugar beet pulp as fed) ad libitum on the development in individual feed intake characteristics and reproductive performance during three successive reproduction cycles. Performance of the ad libitum-fed sows was compared to the performance of sows that were fed a conventional diet restrictedly. Feed intake characteristics during gestation were only measured in the ad libitum-fed sows. One hundred and nineteen sows were assigned to one of two gestation feeding regimens. Gestating sows were fed a conventional Dutch diet restrictedly or a diet with a high level of fermentable NSP ad libitum. During lactation, sows were given free access to a commercial lactation diet from d 6 after parturition onward. The ad libitum-fed sows ate 1.3 kg/d more during gestation than the restrictedly fed sows (P < 0.001), resulting in higher body weight and backfat gains during gestation (P < 0.05). Sows that were fed ad libitum during gestation lost more body weight and backfat during lactation (P < 0.001) than sows that were fed restrictedly during gestation. Feed intake during lactation, however, did not differ between sows that were fed restrictedly or ad libitum during gestation. The numbers of total piglets born, live-born and stillborn piglets, piglet birth weight, weaning-to-estrus interval, and percentage of sows that returned to estrus after first insemination were not affected by gestation feeding regimen. Mean daily voluntary feed intake (as-fed basis) over the three reproduction cycles in the ad libitum-fed gestating sows was 4.2 kg/d. Depending on the number of preceding reproduction cycles during which a sow was fed ad libitum, the maximum voluntary feed intake was reached in Parity 3, 4, or 5 and then remained stable in subsequent parities. Mean daily feed intake of the ad libitum-fed sows increased from wk 2 to 6 of gestation and then decreased to wk 15 of gestation. The mean number of daily visits with feed intake over the three reproduction cycles was 13.8. On average, ad libitum-fed sows spent 90 min/d on eating. This study shows that it is possible to feed gestating sows a diet with a high level of fermentable NSP ad libitum during three successive reproduction cycles without negative effects on reproductive performance.     

Effect of feather meal as a source of valine for lactating sows

An experiment was conducted to evaluate feather meal as a source of Val in lactating sow diets. Sows (five farrowing groups; mean parity = 2.34) were allotted to one of two dietary treatments on the basis of ancestry, parity, and weight and date of d 110 of gestation. The treatment diets included 1) corn-soybean meal lactation diet (n = 40) or 2) corn-soybean meal lactation diet with 2.5% feather meal (n = 39). The diets were formulated on an equal Lys basis. All litters were adjusted to 10 pigs within 24 h after farrowing, and all sows weaned at least nine pigs. Sows were bled at 110 d of gestation and at weaning, and serum urea N was determined. Backfat thickness was determined ultrasonically at 110 d of gestation and at weaning. Serum urea N and backfat thickness at d 110 of gestation were used as covariates for serum urea N and backfat thickness at weaning, respectively. The litter response criteria (weaning weight, litter weight gain, and percentage survival) were not affected (P > .10) by feather meal. The sow response criteria (weaning weight, weight loss per day, weaning backfat thickness, change in backfat thickness, ADFI, and days to estrus) were not affected (P > .10) by feather meal. Sows fed feather meal had increased (P < .01) serum urea N and tended (P = .15) to have decreased sow weaning weight. Following the initial analysis of the data, the data set was split into two groups: 1) sows with litters gaining less than 2.17 kg/d (n = 19 and 20 for control and feather meal diets, respectively) and 2) sows with litters gaining more than 2.17 kg/d (n = 21 and 19 for control and feather meal diets, respectively). These two groups were analyzed separately. In sows with litters gaining less than 2.17 kg/d, the litter and sow criteria were not affected (P > .10) by treatment. In sows with litters gaining more than 2.17 kg/d, sow weaning weight was decreased (P < .04) and sow weight loss (P < .02) and serum urea N (P < .01) were increased in sows fed feather meal. Feather meal (as a source of Val) did not improve litter weight gain, but it increased serum urea N.     

Lactation feed disappearance and weaning to estrus interval for sows fed spray-dried plasma

Four experiments involving 265, 410, 894, and 554 sows (Exp. 1 to 4, respectively) were conducted to determine the effect of spray-dried plasma (SDP) at 0 or 0.25% (Exp. 1 and 2) and 0 or 0.50% (Exp. 3 and 4) in lactation diets on average daily feed disappearance (FD), sum of sow BW, fetal and placental loss from d 110 gestation to weaning (SWL), litter size at weaning, litter weight at weaning, and average days from weaning to first estrus (WEI). Experiments 1, 3, and 4 were conducted during summer months, and Exp. 2 was conducted during fall to winter months. Experiment 1 used only parity 1 and parity 2 sows and Exp. 4 used only mature (>2 parities) sows, whereas Exp. 2 and 3 used all parity groups. Sows fed SDP in Exp. 1 had increased (P < 0.01) FD and a tendency for reduced (P = 0.06) SWL and WEI (P = 0.06). Sows fed SDP in Exp. 2 had a tendency for increased (P = 0.09) sow BW at weaning and reduced (P = 0.09) SWL, whereas other variables were not different between diets. Parity 1 and 2 sows fed SDP in Exp. 3 had increased (P < 0.01) FD, but mature sows fed SDP had reduced (P = 0.02) FD. Pig survival and litter size at weaning for all parity groups was not different between diets. The WEI for parity 1 sows fed SDP was reduced (P = 0.02) and tended to be reduced (P = 0.10) for mature sows fed SDP, but was not different between diets for parity 2 sows. More parity 1 sows fed SDP were detected (P = 0.01) in estrus 4 to 6 d after weaning, and fewer were detected (P < 0.01) in estrus 6 d after weaning compared with control parity 1 sows. In Exp. 4, FD was reduced (P < 0.01) for mature sows fed SDP; however, litter weight and average pig BW at weaning was increased (P < 0.01) with more (P < 0.01) marketable pigs (pig BW > 3.6 kg) weaned per litter. Relatively low dietary levels of SDP (0.25 to 0.50%) fed to parity 1 sows farrowed during summer months increased lactation FD and reduced WEI. Mature sows fed SDP during summer months consumed less lactation feed without compromising WEI, but had an increased litter weight, average pig BW, and number of marketable pigs at weaning.     

Effects of feeding schedule on body condition, aggressiveness, and reproductive failure in group-housed sows

A total of 208 sows and 288 gilts (PIC line C29) were used to determine the influence of feeding frequency (2 vs. 6 times/d, floor fed) on performance and welfare measurements on a commercial sow farm. Treatments consisted of feeding similar amounts of feed to each sow (2.5 kg) or gilt (2.05 kg) over 2 (0700 and 1530) or 6 times daily (0700, 0730, 0800, 1530, 1600, and 1630). There were 8 sows or 12 gilts in each pen. Gilts and sows were moved to pens 1 to 4 d after breeding. In sows, there were no differences (P > 0.10) in ADG, backfat change, or variation in BW. There was a trend (P < 0.08) for sows fed twice daily to farrow more total pigs born, but number born alive or other reproductive performance traits were not different (P > 0.10) among treatments. Sows fed 6 times per day had increased vocalization during the morning (P < 0.07) and afternoon (P < 0.01) feeding periods compared with sows fed twice daily. Sows fed twice daily had more skin (P < 0.01) and vulva (P < 0.04) lesions as well as a small increase in feet and leg (P < 0.01) and hoof (P < 0.02) problems. In this commercial facility, the standard management protocol required moving gilts to a different gestation facility on d 42. On d 42, two pens of gilts with similar breeding dates and treatment were combined and moved to another facility with larger pens until farrowing. Gilts fed 6 times daily had a tendency for greater ADG (P < 0.07) from d 0 to 42 and a tendency for greater (P < 0.09) backfat on d 42. After movement to the larger groups from d 42 to farrowing, ADG was similar (P > 0.10) for gilts fed 2 or 6 times daily. Gilts fed twice daily had lower BW variation at d 42 (P < 0.04) and tended to at farrowing (P < 0.10). In gilts, there were no differences (P > 0.10) for reproductive performance, skin and vulva lesions, and feet and leg scores. In conclusion, there were few growth, farrowing, or aggression differences among gilts fed 2 or 6 times daily. This suggests that either feeding method is suitable for group-housed gilts. Among sows, feeding frequency resulted in few growth or farrowing performance differences. Feeding 6 times daily resulted in a small but significant reduction in skin and vulva lesions and structural problem scores while increasing vocalization. Increasing the feeding frequency from 2 to 6 times daily does not appear to have a negative or positive impact on performance or welfare of group-housed gilts and sows.