Litter Weaning Weight Research Articles

271 Effects of Increasing Lactation Dietary Energy Concentration by Adding fat During the Summer Period on sow and Litter Performance

Abstract The objective was to determine the effects of increasing energy in lactation diets fed during the summer period on sow and litter performance. A total of 356 sows (PIC Camborough) were randomly assigned at entry into the farrowing room to 1 of 4 treatments within parity in a randomized complete block design with body weight and breeding day blocks. Pre-farrowing caliper scores were balanced across treatments. The trial was conducted from July to September 2021 in Carthage, Illinois, with external barn minimum and maximum temperatures averaging 21-32°C. Treatments consisted of increasing levels of added fat in the lactation diet: 0, 1.67, 3.34, and 5.00% of corn oil. Diets were corn-soybean meal-based with a fixed soybean meal inclusion rate of 28.90%. Net energy (NE) concentrations of the treatment diets consisted of 2.345, 2.427, 2.509, and 2.591 Mcal NE/kg. Sow was the experimental unit and data were analyzed using generalized linear mixed models with the lmer and glmer functions of R. Increasing corn oil inclusion rates marginally (linear, P=0.086) reduced lactation average daily feed intake but did not significantly (P>0.10) impact total or average daily NE intakes. There was no evidence (P>0.05) for treatment effects on sow body weight, sow caliper score or sow backfat depth changes during lactation, percentage of removed and fall-off piglets, pre-weaning mortality, number of weaned pigs, litter weaning weight, total litter weight gain, and piglet average daily gain. In summary, increasing energy in the lactation diet by adding up to 5% corn oil during the summer period resulted in a marginal linear reduction in lactation average daily feed intake, but did not influence daily NE intake. Under the conditions of this study, no evidence for treatment effects were observed for sow or for litter performance during the nursing period.

A genome-wide association study of important reproduction traits in large white pigs

Augmenting the reproductive efficiency of sows remains the predominant challenge in the swine industry. This work was aimed at scrutinizing vital genetic markers for reproductive traits in this animal. This entailed probing of the records of vital attributes of Large White pigs (n = 695) inclusive of the total number of born (TNB), number of born alive (NBA), number of weaned pigs (NWP), number of healthy births (NHS), total litter weight of piglets born alive (BALWT), weaning litter weight (WNWT), and corrected litter weight at 21 days (W21). A genome-wide association study (GWAS) for the four litter traits and three traits of litter weight in the Denmark Large White population then ensued. We discovered seven significantly related SNPs and eleven potential candidate genes (e.g., TUSC3, THRB for TNB; STT3B for NBA). The subsequent functional enrichment analysis of these genes showed that the significant gene were associated with steroid hormone receptor activity. Our findings indicated that the genes TUSC3, THRB and STT3B probably contribute to litter traits in this population. This work reveals genetic mechanisms of reproduction traits and also supports ensuing genetic improvement employing marker-assisted selection in Large White pigs.

246 Awardee Talk: Evaluating the Impact of Essential Fatty Acids in Lactation Diets on Sow and Litter Performance

Abstract Two experiments were conducted to evaluate the effects of supplemental fat sources providing low and high essential fatty acids (EFA) in lactation diets on sow reproductive performance, piglet growth and survivability, and colostrum and milk composition. In Exp. 1, mixed parity sows (n = 91) were allotted to 5 experimental treatments arranged in a 2×2 + 1 factorial. Treatments were corn-soybean meal-based diets that contained no added fat or diets with 3% added fat as either beef tallow or soybean oil starting on d 107 or 112 of gestation. Sows were provided low EFA [linoleic acid (LA) and α-linolenic acid (ALA)] in diets without supplemental fat or with beef tallow or high EFA with soybean oil. Results confirmed that providing fat sources with high EFA can increase colostrum and milk LA and ALA content, regardless of pre-farrow time of diet consumption. However, supplemental fat did not influence litter growth performance (P > 0.05). In Exp. 2, mixed parity sows (n = 3,451) were assigned to 4 corn-soybean meal-wheat-based lactation diets with 0.5 (Control) or 3% choice white grease (CWG), 3% soybean oil (SO), or a combination of 3% soybean oil and 2% choice white grease (Combination) at d 112 of gestation to provide diets with low or high EFA. Lactation ADFI increased (P < 0.05) for sows fed the Combination and CWG diets compared with sows fed the Control or SO diet. Sows fed Combination and SO diets had greater (P < 0.05) LA and ALA intake, LA and ALA in colostrum and milk, litter weaning weights, and litter ADG than sows fed 0.5 or 3% CWG. Sow EFA intake did not affect (P > 0.10) piglet survivability or subsequent sow reproductive performance. In conclusion, increased LA and ALA intake provided by SO during lactation increased overall litter growth and weaning weights but did not affect piglet survivability or subsequent performance.

3 Effect of Litter Size and Provision of Supplementary Liquid Milk Replacer During Lactation on Piglet Pre-Weaning Performance

Abstract Recent increases in litter size in commercial sows have been accompanied by higher pre-weaning mortality (PWM) and lower weaning weights. The objective was to determine effects of litter size and feeding liquid milk replacer during lactation (using an automated feeder) on piglet performance. A split-plot design was used with a 2x2 factorial arrangement of treatments: Milk Replacer (MR; main plot; Unsupplemented vs. Supplemented); Litter Size [LS; sub-plot; Low (2 piglets less than functional teat number) vs. High (2 piglets greater than functional teat number)]. Cross-fostering was carried out at 24 h after birth to create treatment litters with similar gender ratio, proportion of cross-fostered piglets, and average and CV of birth weight. Milk replacer was available from 24 h after birth to weaning. Piglets were weighed on d 1 and 20 (weaning) after birth; all PWM was recorded. Growth data were analyzed using PROC MIXED of SAS; PWM data were analyzed using PROC GLIMMIX. Models accounted for fixed effects of MR, LS, the interaction, and random effects of replicate and replicate by MR interaction. There were no MR by LS interactions (P > 0.05) for any measurement. Supplemented compared with Unsupplemented litters had similar (P > 0.05) litter size at weaning and PWM, but greater (P < 0.05) average piglet and total litter weaning weight (Table 1). The High LS treatment had greater (P < 0.05) litter size and total litter weight at d 1 and weaning, but higher (P < 0.05) PWM and lower (P < 0.05) average piglet weaning weight. In conclusion, supplementing piglets with liquid milk replacer increased weaning weight with no effect on PWM, and increasing litter size above sow teat number had negative effects on both PWM and piglet weaning weight.

PSXI-24 Evaluation of Barbados Blackbelly and St. Croix hair sheep under accelerated lambing using purebred and terminal sire mating: Ewe fertility, prolificacy, and productivity

Abstract Objectives were to evaluate ewe performance under an accelerated, pasture-lambing system. Barbados Blackbelly (n = 85) and St. Croix ewes (n = 91) were exposed to rams of their own breed (pure) or Dorset (terminal) in November (2012 and 2014), July (2013 and 2015), and March (2014 and 2016). Traits considered were fertility (i.e., ewes lambing/ewes exposed; n = 670) and number of lambs born (NLB), number of lambs weaned (NLW), and total 65 d adjusted litter weaning weight (LWW; n = 548 each). Data were analyzed with fixed effects of ewe age (1, 1.5, 2 yr, or ≥ 2.5 yr), breed, mating system (pure vs terminal), mating month-year, and the mating system x mating month-year interaction and a random ewe effect. Fertility was greater for Barbados Blackbelly than St. Croix ewes (0.88 vs 0.73; P < 0.01) but ewe breed did not affect any other trait (P ≥ 0.06). The mating system x mating month-year interaction effect impacted all traits (P ≤ 0.03) except NLB (P = 0.09) and performance between mating systems was compared within mating month. Fertility was greater for pure than terminal mated ewes in November (0.96 vs 0.85) and July (0.94 vs 0.53; P ≤ 0.01). Following July mating, both NLB and NLW were greater for pure than terminal mated ewes (1.69 vs 1.37 lambs and 1.43 vs 1.11 lambs, respectively; P < 0.01). However, LWW was greater for terminal than pure mated ewes after November (18.0 vs 15.7 kg) and March mating (18.1 vs 14.2 kg; P ≤ 0.02). Using a terminal sire in landrace hair sheep under accelerated mating generally reduced fertility, NLB, and NLW but improved LWW. The strategic use of terminal sire mating should be considered just during breeding season, or the use of alternative sire breeds should be evaluated.

Social Status Differentially Affects Behavioral and Immunological Outcomes of Group-Kept Sows Fed Different Dietary Fiber Using Different Length Feeding Barriers

Social conflict is inevitable among group-housed sows and may contribute to poorer welfare among those sows experiencing more social stress. The degree of individual welfare is associated with social position within the group. Therefore, this study examined the effects of social status on behavior, immune, endocrine, and productivity of group-housed pregnant sows fed a diet supplemented with 30% wheat middlings and 15% soybean hulls (MID-SH) or 30% distillers dried grains with solubles and 30% corn germ meal (DDGS-GM) and in pens with individual feeding places made from short (58.4 cm) or long (203.2 cm) barriers. A 2 × 2 factorial design resulted in 4 experimental treatment groups (n= 9 sows/diet-length-block combination): (1) MID-SHshort; (2) MID-SHlong; (3) DDGS-GMshort; (4) DDGS-GMlong. Groups of sows equally representing all diet-length combinations across 4 blocks (n= 36 sows/block) were subjected to a feeding competition test to identify highest (dominant) and lowest (subordinate) ranked sows within each group resulting in 64 sows (n= 16 sows/treatment;n= 32 sows/social status). Data revealed 2- and 3-way interactive effects on aggressive behavior (P< 0.005), postural (P< 0.01), oral (P< 0.0001), and eating (P< 0.005) behaviors, sow mean body weights and gains (P< 0.05) and litter weaning weights (P< 0.05), especially among subordinates in pens with long barriers. Subordinates in pens with long barriers received 21% less aggression and were 73% less likely to be displaced than subordinates in pens with short ones (P< 0.0001). Dietary treatment also influenced some of these measures among the subordinates in pens with long barriers. For example, subordinates in DDGS-GMlongreceived 64 and 67% less aggression than subordinates in DDGS-GMshortand MID-SHshort(P< 0.005). Eat bouts were greatest among subordinates in MID-SHlong, and sitting and sham-chewing were less. However, those in DDGS-GMlongspent less time standing and laying, and their litters were 15.28 kg heavier (P= 0.01), but overall subordinates fed DDGS-GM diet were lightest and gained less total body weight than those fed MID-SH (P< 0.05). Other measures such as neutrophil-to-lymphocyte ratio were elevated among dominants in MID-SHlong(P< 0.05); whereas, cortisol (P= 0.06) was lowest and glucose (P= 0.09) highest for subordinates in DDGS-GMlong.These data imply that subordinates benefited from being housed in pens with long barriers, but the type of dietary fiber consumed differentially influenced behavioral budget and several sow- or litter-related traits among subordinates in pens with long barriers. In contrast, the subordinates in pens with short barriers had poorer welfare regardless of diet. Collectively, these data imply that social status is a crucial factor contributing to variation in individual well-being among group-housed sows and that sows of different social positions within a group may evoke different biological responses in an attempt to cope.

Hybrid rye may replace up to 75% of the corn in diets for gestating and lactating sows without negatively impacting sow and piglet performance.

An experiment was conducted to test the hypothesis that hybrid rye can replace a part of the corn in gestation and lactation diets without negatively affecting sow and litter performance. For each phase, a corn-soybean meal diet and three diets in which hybrid rye replaced 25%, 50%, or 75% of corn were formulated. Two hundred sows were randomly allotted by parity to the four treatments. Results indicated that diet did not affect body weight or average daily gain (ADG) of sows or number of pigs born. The number of pigs weaned, litter weaning weight, and litter ADG increased and then decreased (quadratic, P < 0.05) as hybrid rye in diets increased. Pig mortality and number of crushed pigs tended (quadratic, P < 0.10) to be reduced as hybrid rye was added to the diet. Serum cytokines did not differ among treatments on day 105 of gestation or in pigs on the day of weaning, but interleukin (IL)-4, IL-10, and IL-18 on day 13 of lactation increased and then decreased (quadratic, P < 0.05) as hybrid rye inclusion increased in diets. Milk urea N increased (linear, P < 0.05) as hybrid rye was included in the diet, but no other differences in milk composition were observed. Overall, replacing 25% or 50% of corn with hybrid rye resulted in improved lactation performance, and replacing 75% of corn with hybrid rye resulted in sow and litter performance that was not different from that of sows fed control diets.

Flavor supplementation during late gestation and lactation periods increases the reproductive performance and alters fecal microbiota of the sows.

This study was conducted to evaluate the effect of flavor on reproductive performance and fecal microbiota of sows during late gestation and lactation. A total of 20 healthy Yorkshire sows were fed a corn-soybean basal diet unsupplemented or supplemented with 0.1% flavor compound from d 90 of gestation to 25 d post-farrowing, and then the piglets were weaned. The reproductive performance and the fecal microbiota of sows were analyzed. Compared with the controls, flavor supplementation in maternal diets increased (P < 0.05) weaning litter weight, litter weight gain, weaning body weight, and average daily gain of piglets. There was a trend of increase in the average daily feed intake of sows (P = 0.09) by maternal dietary flavor addition. The backfat thickness and litter size were not affected by flavor supplementation (P > 0.05). The 16S rRNA analysis showed that flavor supplementation significantly increased the abundance of Phascolarctobacterium (P < 0.05), but significantly decreased genera Terrisporobacter, Alloprevotella, Clostridium_sensu_stricto_1, and Escherichia-shigella (P < 0.05). Spearman correlation analysis showed that Phascolarctobacterum was positively correlated with the average daily feed intake of sows (P < 0.05), the litter weight gain and average daily gain of piglets (P < 0.05). In contrast, Clostridium_sensu_stricto_1 and unclassified_f__Lachnospiraceae were negatively correlated with the litter weight gain and average daily gain of piglets (P < 0.05). Taken together, dietary flavor supplementation improved the reproductive performance of the sows, which was associated with enhanced beneficial microbiota and decreased potentially pathogenic bacteria in the sows.

145 Effect of Substandard Teats on Piglet and Sow Performance

Abstract The objective of the study was to evaluate sow teat quality in relation to subsequent reproductive throughput. Data included one cohort of 42 Landrace × Large White second parity maternal line sows at the Tidewater Research Station (Plymouth, NC). Functional teats (FUNCTIONAL) were classified pre-farrow as acceptable (ACCEPTABLE) or substandard (SUBSTANDARD). Teats were categorized as SUBSTANDARD when teat size was ≤75% of ACCEPTABLE. At day 20 of lactation, ACCEPTABLE and SUBSTANDARD were assessed for the presence of a swollen mammary gland and piglets observed nursing SUBSTANDARD were recorded (24 piglets from 15 litters). Means for FUNCTIONAL, ACCEPTABLE and SUBSTANDARD were 15.07, 13.59 and 1.48 teats, respectively. Biological dam traits included birth weight (BWT), total number born (TNB), litter size at weaning (LSW) and piglet survival (LSW/TNB). Weaning weight (WWT) was considered a trait of the nurse dam. Means for TNB, LSW, litter BWT and litter WWT were 13.4, 10.9, 17.8 kg and 57.8 kg, respectively. Data was analyzed using a chi-square test for binary traits and linear mixed models for continuous traits. At weaning, a greater (P &amp;lt; 0.01) proportion of ACCEPTABLE had a functional mammary gland when compared to SUBSTANDARD (76 vs. 47%). Within litters, piglets nursing SUBSTANDARD tended (em&amp;gt;P = 0.09) to be 158 grams lighter at weaning in comparison to ACCEPTABLE. Yet BWT of SUBSTANDARD piglets did not differ (em&amp;gt;P = 0.60) from piglets nursing ACCEPTABLE. Across litters, an increase in one SUBSTANDARD tended (em&amp;gt;P = 0.07) to reduce litter WWT by 1.74 kilograms. An increase in one SUBSTANDARD tended (em&amp;gt;P &amp;lt; 0.07) to increase piglet survival by 3.5%. Results suggest substandard teats, identified pre-farrow, are less likely to have a functional mammary gland at weaning, impair piglet quality yet may enhance piglet survival.

Effects of the Inclusion of Fermented Mulberry Leaves and Branches in the Gestational Diet on the Performance and Gut Microbiota of Sows and Their Offspring.

Fermented feed mulberry (FFM), being rich in dietary fiber, has not been fully evaluated to be used in sow’s diet. In this study, we investigated the effects of 25.5% FFM supplemented in gestation diets on the performance and gut microbiota of sows and their offspring. Results showed that the serum concentration of glucose, progesterone, and estradiol were not affected by the dietary treatment, while the level of serum insulin and fecal short chain fatty acid were both reduced in FFM group on gestation day 60 (G60, p < 0.05). Additionally, FFM increased both voluntary feed intake and weaning litter weight (p < 0.05), while decreased the losses of both Backfat thickness and bodyweight throughout lactation (p < 0.05). 16S rRNA sequencing showed FFM supplementation significantly increased the diversity and relative abundance of sows’ fecal microbiota on G60 (p < 0.05). The differential microbiota for sows from FFM group was that Bacteroidetes was increased on G60 while Firmicutes were decreased on Lactation day 7 (L7, p < 0.05), and which for the FFM piglets was that both unclassified_f_Lachnospiraceae on L0 and norank_f_Ruminococcaceae on L7 were increased (p < 0.05). In short, FFM can be recognized as a potential feed ingredient used in sow’s diet.

Genetic Analysis Of Rabbit Litter Traits At Birth And Weaning

Data on 260 litters were used to provide therefore to estimate the heritability and estimates of heritability, repeatability, genetic and phenotypic correlations for litter traits at birth and at weaning. Breed, sire within breed and doe within sire effects were found to be significant, (P&lt;0.05) for litter size at birth and at weaning and for litter weight at birth and at weaning. Heritability estimates of 0.33±0.08, 0.38±0.02, 0.03±0.02 and 0.16±0.05 were obtained for litter birth weight, litter size at birth, litter size at weaning and litter weaning weight, respectively. Repeatability estimates were found to be generally moderate to high. Genetic and phenotypic correlations were positive and significant (P&lt;0.01). Selection for litter size at birth and litter birth weight are likely to result in improved litter size at weaning and litter weaning weight respectively.

Performance of the Indigenous Pigs of Nigeria Under Intensive Management Conditions

OBSERVATIONS on some reproductive traits were made on 63 litters of indigenous pigs obtained from pigs selected from an initial group of 60 pigs purchased from local farmers around Ibadan between April 1972 and February 1976. Studies on the growth rate, feed intake and feed efficiency, as well as the proportion of separable tissue in carcass at different terminal weights, rate and efficiency of tissue growth were also carried out with a total of 394 pigs obtained from these litters. For the observations on performance, tissue proportions, tissue growth rate and efficiency of tissue deposition, Large White x Landrace pigs of the same age group were used for comparison at each stage. Litter size averaged 6.7 piglets per sow with a range value of between 4 and 13 piglets. Mean litter birth weight was 6.10 kg, while mean litter weaning weight was 29.4 kg. A preweaning mortality of 15.8% and 4.79% still births were recorded for these indigenous pigs. Daily gain, feed intake and feed conversion efficiency were lower for the indigenous compared to Large White X Landrace pigs. Maximum growth rate for these pigs occured in the growth phase between 45.5 and 56.8 kg. liveweights. Tissue growth rates were lower and the efficiency of tissue deposition poorer in the indigenous compared to the Large White x Landrace pigs. The basic factor underlying the differences in performance of these two breeds would appear to be the inherently different patterns of growth of the respective tissue. The rate and efficiency of tissue growth as well as growth and efficiency of feed utilisation, together indicate that the indigenous pigs should not be reared beyond liveweights between 45.5 and 56.8 kg.&#x0D;

RESPONSE OF BREEDER RABBITS TO VARYING LEVELS OF PELLET IN A MIXED FEEDING REGIME

The response of breeder rabbits to five levels ofl for breeding rabbits rabbit pellets (100, 80, 60, 40 and 20%) in a mixed feeding regime with Ipoinea batatas vines was examined. Thirty sexually mature New Zealand White rabbits, 5 bucks and 25 does, literature on optimuri pellet combination level were used with the aim of determining the most economic and optimum level under the humid environment. Average litter sizes at birth and weaning and litter weaning weight were not significantly (P&gt;0.05) different between diets containing 100 and 80% pellet but these differed significantly (P &lt;0.05) from others. Average litter weight gains (0-35 days) for the various pellet levels were 2102.91g (100%), 2105.27 (80%), 1802.47g (60%), 1285.01g (40%)and 1202.77g (20%). Mortalities were not significantly different (P&gt;0.05) among the diets. From the economic standpoint therefore, a diet with 80% pellet could be considered optimum, based on results on litter sizes, litter weight at weaning and mortality.

Increasing creep pellet size improves creep feed disappearance of gilt and sow progeny in lactation and enhances pig production after weaning

Objective: To determine if feeding a larger diameter pellet increases creep feed intake and growth rate of piglets during lactation, especially that of gilt progeny (GP) compared to sow progeny (SP), and stimulates feed intake after weaning. Materials and methods: Over two replicates, GP and SP (n = 2070) were allocated to two creep feed treatments, receiving either a 4 mm diameter × 4 mm length pellet or a 9 mm diameter × 12 mm length pellet, from 3 days of age until weaning. After weaning, pigs were split into male and female pens according to the type of pellet fed in lactation and fed a common diet. Feed disappearance was recorded before and after weaning (up until 10 weeks of age), along with piglet growth performance and all piglet mortalities and removals. Results: Total creep feed disappearance in lactation was higher (P &lt; .001) in litters offered the larger pellet, but litter weaning weight for GP was not improved (interaction, P &gt; .05). Gilt progeny were weaned lighter (P &lt; .001) than SP. After weaning, pigs offered the larger pellet during lactation showed a tendency to receive less medication (P = .07) than pigs offered the smaller pellet. Growth rate and feed intake after weaning were both stimulated (P = .02 and P = .09, respectively) in pigs offered the larger pellet during lactation irrespective of sex. Implications: Offering a larger pellet creep feed to piglets in lactation can improve postweaning performance and reduce the postweaning medication rate.

Effect of high-phytase supplementation in lactation diets on sow and litter performance.

A total of 109 sows (Line 241; DNA, Columbus, NE) were used to evaluate the effect of increasing dietary phytase in lactation diets, already adequate in P, on sow and litter performance. On d 107 of gestation, sows were blocked by body weight and parity and allotted to 1 of 3 dietary treatments of increasing phytase concentration (0, 1,000, or 3,000 FYT/kg; Ronozyme HiPhos GT 2700, DSM Nutritional Products, Inc., Parsippany, NJ). The control diet contained no phytase and was formulated to contain 0.50% standardized total tract digestible phosphorus (STTD P; 0.45% available P) and 0.62% STTD calcium (0.90% total Ca). The phytase diets that contained 1,000 or 3,000 FYT/kg were also formulated to 0.50% STTD P and 0.62% STTD Ca including the release of 0.132% STTD P and 0.096% STTD Ca. Diets were balanced for net energy and fed from d 107 of gestation until weaning (d 18 ± 3). All farrowings were monitored, with farrowing duration starting at the time the first pig was born until the first dispersal of placental tissues with no subsequent pigs born. Litters were cross-fostered within treatment until 48 h postfarrowing to equalize litter size. There were no differences among treatments in sow body weight at d 107 of gestation, 24 h after farrowing, or at weaning. Sow average daily feed intake from farrowing to weaning tended to increase (linear, P = 0.093) as phytase increased. There was no evidence for difference in the number of total born pigs, as well as the percentage of stillborns, mummies, and born alive pigs at the completion of farrowing. Similarly, phytase supplementation did not influence (P > 0.05) wean-to-estrus interval or litter size after cross-fostering among dietary treatments. Although not significant (linear, P = 0.226), farrowing duration decreased as added phytase increased with a decrease of 47 min (12%) for 3,000 FYT compared with the control. There were no differences in pig weight at weaning, but as a result of increased survivability (linear, P = 0.002), litter weaning weight and overall litter weight gain increased (quadratic, P < 0.05) up to 1,000 FYT of added phytase with no further benefit observed in sows fed 3,000 FYT. In conclusion, sow feed intake tended to increase linearly with increasing added phytase. Feeding 1,000 FYT/kg maximized overall litter gain and weaning weight; however, a larger-scale study with more sows is needed to determine the addition of phytase in lactation diets to reduce farrowing duration.

268 Administration of a Bacillus probiotic to sows improves growth response and health of their progeny after weaning

Abstract A Bacillus probiotic administered to sows was evaluated to determine the effect on their litters and subsequent pig growth response during the nursery phase. The study included 500 sows (250 sows/trt) fed a control or treatment diet with two Bacillus subtilis strains administered at 3.7x105 CFU/g of feed beginning three days after mating. Pigs (n=1,100) weaned from the sow phase were divided into 44 pens (22 pens/trt) and fed a common diet to determine the effect of sow treatment on post-weaning growth performance. Fecal samples were collected from a subset of sows (25/trt) at d112 of gestation and d19 of lactation, and from two pigs/pen in the nursery on d3 post-weaning for microbial enumeration. A blood sample was obtained from two pigs/pen on d3 and serum cytokines and the acute phase protein, α-1-acid glycoprotein (AGP) were quantified. Data were analyzed using the MIXED procedure of SAS; sow/litter and pen served as the experimental unit. Litter weaning weights did not differ, but Escherichia coli counts were lower (P≤0.05) on d112 in fecal samples from sows fed Bacillus compared to control sows. Lactic acid bacteria counts were greater (P≤0.01) on d3 post-weaning in pigs weaned from sows fed Bacillus compared to control pigs. Nursery pigs weaned from sows fed the Bacillus probiotic had greater (P≤0.01) ADG and G/F during Phase1 (d 0-11), greater (P≤0.01) ADG and ADFI during Phase3 (d 23-37) and were 0.91 kg heavier (P≤0.01) at the end of the nursery phase (d 51) compared to pigs from control sows. The administration of Bacillus to sows resulted in lower AGP (P≤0.05) and greater tumor necrosis factor-α (P=0.08) serum concentrations on d3 post-weaning and reduced (P≤0.05) the percentage of nursery pigs removed from the trial and placed in invalid pens compared to pigs from control sows. These data indicate that a Bacillus probiotic improves sow health and the lactation environment and has a substantial impact on the subsequent productivity of their progeny.

269 Effects of high phytase supplementation in lactation diets on sow and litter performance

Abstract A total of 109 sows (Line 241; DNA, Columbus, NE) were used in a study to evaluate the effect of increasing phytase concentration in lactation diets on sow and litter performance. On d 107 of gestation, sows were blocked by body weight and parity and allotted to 1 of 3 dietary treatments of increasing phytase concentration (0, 1,000, or 3,000 FYT/kg; Ronozyme HiPhos 2700; DSM Nutritional Products, Inc., Parsippany, NJ). The control diet contained no phytase and was formulated to contain 0.50% standardized total tract digestible phosphorus (STTD P; 0.45% available P) and 0.62% STTD calcium (0.90% total Ca). The same STTD P and Ca concentrations were formulated for the phytase diets considering a release of 0.132 STTD P and 0.094 STTD Ca in both diets. Diets were fed from d 107 of gestation until weaning (d 18 ± 2). Litters were cross-fostered within treatment until 48 h post-farrowing to equalize litter size. Linear and quadratic response to phytase concentration was evaluated using the lmer function in R. There was no evidence for difference in sow body weight change, farrowing performance, wean-to-estrus interval, or litter size among dietary treatments. Sow average daily feed intake from farrowing to weaning tended to increase (linear, P=0.093) as phytase increased. Although not significant (linear, P =0.226), farrowing duration decreased as phytase increased. Litter weaning weight increased (quadratic, P=0.039) and overall litter gain increased (quadratic, P=0.047) with 1,000 FYT of phytase. In summary, sow feed intake tended to increase linearly with increasing phytase; however, feeding 1,000 FYT/kg maximized overall litter gain and weaning weight. This small-scale study suggests sow and litter performance benefits due to high inclusions of dietary phytase; however, a commercial trial with more sows is warranted to confirm these results.

222 Effect of genetic line and parity of dam on litter birth weight and weaning weight in swine

Abstract The objective of this study was to evaluate the effects of parity and genetic line of the dam on her offspring and their ability to thrive until weaning. Data were obtained from 17 purebred litters and 72 crossbred litters and the parity of the dam ranged from 1-13. Parities were grouped into the following categories: parity 1, parity 2, parity 3-5, and parity 6+. Entire litters were weighed at birth and weaning (~28 days of age). Litters were grouped into four weight categories based on the time of year they were born: February, April, May, and July 2019. Data were analyzed by using mixed model methods (Proc Mixed, SAS V. 9.4, SAS Inst. Inc. Cary, NC). The birthweight model included fixed effects of parity and genetic line. Birth month was included as a random variable, and number born alive was used as a covariate. Mean litter birth weight was significantly different between parity 1 and parity 3-5 (P=0.001), parity 2 and parity 6+ (P=0.031), and parity 3-5 and parity 6+ (P=&amp;lt; 0.0001). The difference between parity 2 and parity 3-5 approached significance. Birthweight differed between genetic line (&amp;lt; 0.0001): Crossbred litter birthweight was 4.15kg greater than purebred litter birthweight. The weaning weight model included genetic line, parity, and number of pigs after fostering. Birth month was included as a random variable, and age at weaning and birth weight were used as covariates. Weaning weights for parity and genetic line did not differ (P &amp;gt;0.05).

279 Development, selection criteria, and performance of Composite IV sheep at the U.S. Meat Animal Research Center

Abstract Average ewe prolificacy is low across the U.S., while fixed and variable costs of production can be substantial, especially in traditional shed-lambing systems. Pasture-lambing can reduce input costs but can present greater risk of inclement weather, predation, and internal parasitism. The Composite IV is a ½ Romanov, ¼ Katahdin, and ¼ White Dorper hair sheep developed at the U.S. Meat Animal Research Center. Objectives were to summarize Composite IV ewe and lamb performance under a pasture-lambing system with minimal disruption through weaning. Lamb survival to and body weight at weaning were greatest for singles (0.90 and 19.9 kg, respectively), intermediate for twins (0.82 and 15.9 kg), and lowest for triplets (0.65 and 14.6 kg; P &amp;lt; 0.01). Number of lambs born and weaned per ewe lambing were lower at 1-yr of age (1.55 and 1.24, respectively) than at 3- to 5-yr of age (2.20 to 2.23 and 1.75 to 1.82; P &amp;lt; 0.01). Within mature ewes (2- to 5-yr-old), twin litters were most frequent (58.7%), triplets intermediate (24.7%), and singles least (16.6%). While number of lambs weaned and total litter weaning weight were greater for triplet- than twin-bearing ewes (2.06 vs 1.70 and 28.9 vs 26.0 kg, respectively; P &amp;lt; 0.01), triplet-bearing ewes lost 1.78 lambs per additional lamb weaned. Results suggest productivity in pasture-lambing systems can be enhanced by identifying complementary breed combinations, maintaining heterosis, and selecting for characteristics associated with reduced labor and enhanced well-being.

21 Comparison of Savanna, Kiko, and Spanish Sires for Meat Goat Doe-Kid Traits

Abstract Savanna sires were evaluated for kid preweaning and doe reproductive traits over six years. Savanna (n = 17) and Kiko (n = 13) sires were bred to Kiko-base does producing 600 kids. Savanna (n = 17) and Spanish (n = 11) sires were bred to Spanish-base does producing 456 kids. Doe traits were evaluated on 536 Kiko and 441 Spanish doe exposures. Kids were weighed at birth and when weaned at 3 mo of age. Non-genetic factors sex and litter size influenced (P &amp;lt; 0.05) kid performance traits as expected. Birth weights of kids from Kiko does were heavier (P &amp;lt; 0.01) for Savanna sires than Kiko sires (3.11 vs. 2.83 ± 0.08 kg). Birth weights of kids from Spanish does were heavier (P &amp;lt; 0.01) for Savanna sires than Spanish sires (3.05 vs. 2.76 ± 0.09 kg). Sire breed did not affect (P &amp;lt; 0.05) weaning weight from Kiko does (15.0 vs 14.8 ±0.6 kg). Savanna sires generated heavier (P &amp;lt; 0.05) weaning weights than Spanish sires (14.2 vs. 13.3 ± 0.6 kg) from Spanish does. Sire breed did not affect ADG or kid survival rates in either doe group. Non-genetic factors litter size and age of dam affected (P &amp;lt; 0.05) doe performance traits in both doe groups. Savanna sires produced heavier litters (P &amp;lt; 0.01) at birth compared to Kiko sires on Kiko does (10.7 vs. 9.7 ± 0.4 kg) and compared to Spanish sires on Spanish does (9.4 vs. 8.3 ± 0.5 kg). Service sire breed did not affect kidding or weaning rate, number of kids born or weaned, or litter weaning weight in either doe group. Savanna sires consistently increased birth weight values. Sire breed did not consistently affect weaning weight values and did not influence other preweaning kid traits or doe reproductive traits.