Progeny Performance Research Articles

Reproductive resilience to habitat fragmentation of Lithraea molleoides (Anacardiaceae), a dominant dioecious tree from the Chaco Serrano

Most of the earth's surface has been transformed by man into urbanized and cultivated areas, decreasing and fragmenting the remaining natural habitats. These changes result in decreased plant population sizes and increased isolation among remaining populations. Because dioecious plant species have male and female flowers in different individuals, they are obligately outcrossing and highly dependent on pollination vectors. Thus, reductions in population size and changes in their sex ratio after deforestation can be significantly drastic for their reproduction. While much research has been conducted assessing habitat fragmentation effects on sexual reproduction of populations of hermaphrodite species, very little is known about the effects on dioecious species. Here, we simultaneously assessed habitat fragmentation effects on the phenological patterns, sex ratios, reproductive ecology and progeny performance of the Chaco Serrano dominant native dioecious tree Lithraea molleoides. In contrast to our initial hypotheses, we found that neither conspecific flowering density, sex ratios, nor flowering phenology of L. molleoides was affected by habitat fragmentation. Lastly, progeny performance was not affected by habitat fragmentation either. Our overall findings across three reproductive seasons show that this dioecious species is resilient to changes imposed by habitat fragmentation. We discuss the particular combination of ecological traits of L. molleoides that may be conferring reproductive resilience, such as ambophilous pollination system and the capability of asexual seed production through apomixis, which may be shared by other woody native dioecious species.

Supplementing organic-complexed or inorganic Co, Cu, Mn, and Zn to beef cows during gestation: postweaning responses of offspring reared as replacement heifers or feeder cattle.

One hundred and ninety nonlactating, pregnant beef cows (¾ Bos taurus and ¼ Bos indicus; 138 multiparous and 52 primiparous) were assigned to this experiment at 117 ± 2.2 d of gestation (day 0). Cows were ranked by parity, pregnancy type (artificial insemination = 102, natural service = 88), body weight (BW) and body condition score, and assigned to receive a supplement containing: (1) sulfate sources of Cu, Co, Mn, and Zn (INR; n = 95) or (2) an organic complexed source of Cu, Mn, Co, and Zn (AAC; Availa4; Zinpro Corporation, Eden Prairie, MN; n = 95). The INR and AAC provided the same daily amount of Cu, Co, Mn, and Zn, based on 7 g of the AAC source. From day 0 to calving, cows were maintained in a single pasture and segregated 3 times weekly into 1 of 24 individual feeding pens to receive treatments. Calves were weaned on day 367 (200 ± 2 d of age), managed as a single group for a 45-d preconditioning period (days 367 to 412), and transferred to a single oat (Avena sativa L.) pasture on day 412. Heifer calves were moved to an adjacent oat pasture on day 437, where they remained until day 620. Heifer puberty status was verified weekly (days 437 to 619) based on plasma progesterone concentrations. Steer calves were shipped to a commercial feedlot on day 493, where they were managed as a single group until slaughter (day 724). Plasma cortisol concentration was greater (P = 0.05) in AAC calves at weaning but tended to be less (P = 0.10) on day 370 compared with INR calves. Mean plasma haptoglobin concentration was greater (P = 0.03) in INR vs. AAC calves during preconditioning, and no treatment effects were noted (P = 0.76) for preconditioning average daily gain (ADG). Puberty attainment was hastened in AAC heifers during the experiment (treatment × day; P < 0.01), despite similar (P = 0.39) ADG between treatments from days 412 to 620. Expression of myogenin mRNA in the longissimus muscle was greater (P = 0.05) in INR vs. AAC heifers on day 584. No treatment effects were detected (P ≥ 0.24) for steer ADG from day 412 until slaughter, nor for carcass quality traits. Hepatic mRNA expression of metallothionein 1A was greater (P = 0.02) in INR vs. AAC steers on day 586. In summary, supplementing Co, Cu, Zn, and Mn as organic complexed instead of sulfate sources to beef cows during the last 5 mo of gestation did not improve performance and physiological responses of the steer progeny until slaughter, but hastened puberty attainment in the female progeny reared as replacement heifers.

The Influence of Maternal Dietary Intake During Mid-Gestation on Growth, Feedlot Performance, miRNA and mRNA Expression, and Carcass and Meat Quality of Resultant Offspring

This research analyzed how maternal plane of nutrition during mid-gestation impacts growth, blood metabolites, expression of microRNA and messenger RNA in skeletal muscle, feedlot performance, and carcass characteristics of progeny. Thirty-two cows were bred to the same Angus sire and fed to either maintain a body condition score (BCS) of 5.0 to 5.5 (maintenance [MAIN]; n = 15) or to lose 1 BCS (restriction [REST]; n = 17) over an 84-d period of mid-gestation. Following the second trimester, all cows were co-mingled and fed at maintenance for the remainder of gestation. Following the 84-d treatment period, REST cows had a lower (P &amp;lt; 0.01) BCS than MAIN cows. At the end of the third trimester, there was no difference (P = 0.78) in BCS between the treatment groups. There was no difference (P &amp;gt; 0.10) between offspring in birthweight, weaning weight, average daily gain, feed efficiency, dry matter intake, carcass yield, steak quality, or in circulating levels of glucose, cortisol, insulin, or insulin-like growth factor-1. REST offspring expressed more (P &amp;lt; 0.05) miR-133a, miR-133b, miR-181d, miR-214, miR-424 and miR-486 at weaning than MAIN offspring. At harvest, REST offspring expressed more (P &amp;lt; 0.05) miR-133a and less (P &amp;lt; 0.01) miR-486 than MAIN offspring. REST steaks were perceived as more tender (P = 0.05) by a trained sensory panel. These results indicate that maternal nutrient restriction during mid-gestation resulting in a loss of 1 BCS has an effect on microRNA expression in the skeletal muscle but does not alter postnatal growth potential, carcass quality, or end product quality of the offspring. This suggests that moderate restriction in maternal nutrition during the second trimester, which results in a drop in BCS that can be recovered during the third trimester, should not cause alarm for producers when considering future offspring performance.

Identification of Genomic Regions for Carcass Quality Traits within the American Simmental Association Carcass Merit Program.

Simple SummaryThe American Simmental Association has an ongoing project assessing carcass composition and quality. Typically, when animals for mating are selected on maternal traits, there is a concomitant reduction in carcass value as many maternal traits are antagonistic to carcass traits. Analysis of the current data showed the correlation between hot carcass weight and calving ease direct to be lower than previously reported. This shows that multi-trait selection reduced the problem that arose when selecting for carcass traits or maternal traits individually.USDA quality and yield grade are primary driving forces for carcass value in the United States. Carcass improvements can be achieved by making selection decisions based on the results of genetic evaluations in the form of expected progeny differences (EPD), real-time ultrasound imaging, and physical evaluation of candidate breeding animals. In an effort to advance their ability to accurately predict the breeding value of potential sires for carcass traits, the American Simmental Association launched the Carcass Merit Program as a means to collect progeny sire group carcass information. All records were extracted from the American Simmental Association database. Progeny data were organized by sire family and progeny performance phenotypes were constructed. Sire genotypes were filtered, and a multi-locus mixed linear model was used to perform an association analysis on the genotype data, while correcting for cryptic relatedness and pedigree structure. Three chromosomes were found to have genome-wide significance and this conservative approach identified putative QTL in those regions. Three hundred ninety-three novel regions were identified across all traits, as well as 290 novel positional candidate genes. Correlations between carcass characteristics and maternal traits were less unfavorable than those previously reported.

The effect of a fodder beet versus rye-grass grazing regime during mid-to-late gestation twin-bearing ewes on dam and progeny performance and lamb survival

ABSTRACT The objective was to determine the effect of grazing fodder beet versus ryegrass-dominant pasture from mid-to-late gestation on dam and offspring performance under practical farming conditions. Twin-bearing ewes were randomly allocated to grazing regimes of either fodder beet plus ad libitum ryegrass/clover hay (FB; n = 100) or ryegrass-dominant pasture plus ad libitum ryegrass/clover hay (RG; n = 100) with three replicates per group, from pregnancy day (P) 100–110 to birth. At P135, 10 ewes per treatment were randomly selected from each replicate, slaughtered and back fat and eye muscle depth and fetal body weight and composition were measured. Samples were evaluated for selected blood metabolites. Ewe BW and BCS change and lamb growth were measured, and lamb survival from birth to weaning calculated. Compared with RG, FB ewes had lower ADG and overall lower BCS resulting from increased mobilisation of both fat and muscle. Lambs born to FB-ewes had lower BW and postnatal growth rates and increased mortality from birth to weaning (29% versus 12%). Body composition and blood parameters indicated that FB compared to RG ewes were subject to undernutrition. This study provides new insights into the consequences of FB grazing regimes, as an alternative to ryegrass pasture, on animal performance.

Effects of Symbiodiniaceae Phylotypes in Clades A–E on Progeny Performance of Two Giant Clams (Tridacna squamosa and T. crocea) During Early History Life Stages in the South China Sea

Unlike most bivalves, giant clams (tridacnids) harbor symbiotic microalgae (zooxanthellae) in their other fleshy bodies. The effects of mixed populations of zooxanthellae on larval metamorphosis has been reported in several papers, but there have been very few studies on the effects of single zooxanthella species on the establishment of symbiosis in giant clams. In this study, we obtained five pure zooxanthella species (clades A3, B1, C1, D1, E1) from antler coral by molecular identification, and analyzed their effects on the larval metamorphosis and progeny performance of two giant clams, Tridacna squamosa and T. crocea, in the South China Sea. Clam larvae with all five zooxanthella species underwent larval settlement and metamorphosis, and formed the zooxanthellal tubular system. There was some variation in metamorphic rate and time to metamorphosis between clams with different zooxanthella species, but no significant differences in size at metamorphosis. After metamorphosis, larvae with all zooxanthella types continued to develop normally. Mantle color was consistent within clam species and zooxanthella species had no effect on mantle color. However, clam progeny with clade E1 zooxanthellae were smaller than progeny with the other four zooxanthella clades (A3, B1, C1, and D1). Survival rate was over 90% for all progeny and there were no significant differences in survival between progeny with Symbiodinium clades A–E during the entire culture process. Two-way ANOVA analysis revealed that giant clam species was the main factor influencing progeny growth, with some variation in growth attributable to zooxanthella type. Our results provide new information on both the symbiotic relationship between giant clams and zooxanthellae and the mantle coloration of giant clams, and will be useful in giant clam seed production and aquaculture.

Comparison of growth performance and biochemical components between parent and hybrid offspring in the oriental river prawn, Macrobrachium nipponense.

Macrobrachium nipponense, as one of the large-yield farmed shrimp, is facing germplasm degradation. Genetic improvement through hybridization is one of the effective methods to solve this problem. In this study, using a three-line hybrid strategy, two-hybrid F1 populations were obtained using three local populations of M.nipponense as parents for crossbreeding. Five populations were then cultured for 3months. Growth rate performance was measured by the hepatosomatic index, weight gain, body length growth rate and special growth rate. Biochemical components were also assessed. The results showed that the survival rate and growth performance of the hybrid progeny were better than those of the parents. The levels of triglycerides, total cholesterol, glycogen and lactic acid of the hybrid population were higher than those of the parents. This was consistent with variation in the activity of four digestive enzymes. Compared with the results of the fatty acid and amino acid analysis, it was found that the contents of polyunsaturated fatty acids such as eicosapentaenoic acid, docosapentaenoic acid and docosahexaenoic acid and eight essential amino acids in the hybrid populations were significantly higher than those of their parents, and the contents of flavor amino acids were higher. The expression level of molting genes related to the growth of the parent populations was lower than that of the hybrids. These results show that crossbreeding is effective for the genetic improvement of M.nipponense germplasm. Hybrids showed advantages in growth and nutrition and multigenerational breeding will be required to form a stable germplasm.

COMPARATIVE GROWTH AND CARCASS PERFORMANCE OF PROGENIES SIRED BY PUREBRED LARGE WHITE AND HAMPSHIRE BOARS AND THEIR CROSSES WITH THE NIGERIAN LOCAL BREED

THE performance of progenies sired by purebred Large White and Hampshire boars and their crosses with Nigerian local breed — the Large White x Local and Hampshire x Local boars was compared from birth to slaughter at 60kg liveweight using 4 boards each of the different breeds and crosses. 4 boars from each of 16 litters sired per breed compris­ing 4 dams mated per sire were evaluated. Feeding was twice daily up to a maximum of 2.00kg meal per day. Among the boar genotypes, significant differences in performance between progeny was found for the backfat thickness (P 0.01). Carcass length and average daily gain (P 0.05). The progenies of the Hampshire boar were 0.61kg heavier than those of the crossbred boar at birth, had higher weaning weight (2kg heavier) and a significantly different (P 0.05) average daily gain to slaughter. The progenies of purebred boars were 4.04 and 6.89 days earlier to slaughter, had 1.4 and 1.5% higher carcass yield but 1.9 — 3.44mm higher back-fat than the progenies from corresponding crossbred boars. Significant breed differences were noted in the prime cuts of the carcasses.

Effect of feathering genes on growth performance of F2 backcrosses and comparison of F1 and F2 crosses of Abor Acre broiler breeder x native chickens in humid tropical environment

This study was conducted to evaluate growth performance, brooding and rearing mortalities of F2 main and reciprocal backcross progenies of Abor Acre broiler breeder x native chicken crosses and to compare their F1 and F2 backcross progenies. The base population used in the study consisted of mature (~ 48 weeks) male and female native chickens and exotic (Abor Acre) broiler breeder parent stock. The native chicken varieties were made up of normal feather, naked neck and frizzle genotypes. These birds were mated to the Abor Acre broiler parent stocks in main and reciprocal fashion generating F1 main and reciprocal crossbreds. Females of these F1 hybrids were then mated back to the broiler breeder cock to generate F2 main and reciprocal backcross progenies that were evaluated in the present study. Data analyzed include body weight (BWT) and linear body parameters (LBPs), average feed intake (AFI), feed conversion ratio (FCR), brooding and rearing mortalities. Comparisons between genetic groups for these parameters were done by means of analysis of variance (ANOVA) technique. Results indicated improved growth performance and feed conversion ratios in the F2 reciprocal backcross groups compared to their F2 main backcross counterparts. The F2 individuals in both crosses were superior to F1 crossbred populations. Chick mortality rates were higher in main and reciprocal backcross groups involving the naked neck genotype compared to other plumage types. It was concluded that backcrossing the F1 individuals to the exotic broiler breeder cocks increased the genetic profile of the backcross lines resulting in enhanced growth performance of progenies. Crossbreeding of exotic and local chicken varieties generated progenies that had higher genetic potentials for growth relative to the local strains and better adaptability relative to the exotic breed. However, incubation and brooding strategies capable of minimizing mortalities at embryonic, brooding and rearing phases should be explored and integrated in local chicken improvement programmes involving the use of these plumage reducing genes for optimal results.

Evaluation of early growth performance of backcross progenies from crossbred gilts mated with their native parents

The pre weaning growth performance of piglets from four different cross bred dams mated back to their native parents was studied in the Breeding and Research Farm of Ebonyi State University, Abakaliki. Parameters like body weight, weight gain, feed intake and feed efficiency as well as linear body measurements of body length, heart girth and height at withers were taken and observed for growth between birth and weaning age of eight weeks. Results Results indicated significant differences (P&lt;0.05) between the main backcross N x (N x LR) and the three other genotypes of N x (N x LW), N x (LR x N) and N x (LW x N) in all parameters. The mean birth weight of the progenies ranged from 1.00±0.60 to 1.60±5kg while the weaning weights were 10.5±0.4 to 16.0±1.0kg respectively. Results further revealed that body weight at weaning correlated responsively with all parameters and these include body length (r=0.858), heart girth (r= 0.446) and height at the withers (r= 0.946). Similarly, body length has a positive correlation with heart girth (r= 0.477) and height at the withers (r= 0.827) whereas hear girth correlated positively with the height at the withers (r= 0.494). Similar trend were obtained in the regression of each of the body measurements on the other in which bodyweight changes depended more on that of body length (0.86) than on heart girth (0.45). Judging from the observed variations existing among the piglets resulting from differnt crossbreed dams in their pre-weaning growth performance, maternal rather than paternal influences appeared to be more important in the traits studied.

Effect of Oral Administration with Lactobacillus plantarum CAM6 Strain on Sows during Gestation-Lactation and the Derived Impact on Their Progeny Performance.

Background To evaluate the biological response of the sows and their offspring with oral administration of Lactobacillus plantarum CAM6 in breeding sows, a total of 20 Pietrain breeding sows with three farrowings and their descendants were used, randomly divided into two groups of 10 sows each. Treatments included a basal diet (T0) and basal diet +10 mL biological agent containing 109 CFU/mL L. plantarum CAM6 (T1). No antibiotics were used throughout the entire experimental process of this study. Results The L. Plantarum CAM6 supplementation in sows' feeding did not affect (P > 0.05) the reproductive performance of the sows; however, the number of deaths for their offspring before weaning (P ≤ 0.05) decreased. In addition, the oral administration of Lactobacillus plantarum CAM6 in sows increased (P ≤ 0.05) the content of lactose, nonfat solids, mineral salts, and the density of sows' milk, with a decrease in milk fat. Moreover, the probiotic feed orally to the sows improved the body weight (P ≤ 0.05) and reduced the diarrhea incidence of their offspring (P ≤ 0.05). Also, the probiotic administration of sows changed (P ≤ 0.05) the serum concentration of Na+, pCO2, and D-β-hydroxybutyrate and increased (P ≤ 0.05) the leukocytes, lymphocytes, and platelets in their piglets. Conclusion Oral administration of Lactobacillus plantarum CAM6 in breeding sows improved body weight, physiological status, and the health of their offspring. And preparing the neonatal piglets physiologically is of great importance to the pig farming industry which could decrease the operational cost and medication (especially antibiotics) consumption of the pig producers.

Fire frequency effects on cleistogamy expression and progeny performance in Cologania broussonetii.

Increased fire frequency usually erodes microenvironmental conditions, causing a drastic limitation of edaphic resources. Thus, the production of permanently closed-small flowers (cleistogamous, CL) should increase in sites with high fire frequency as this implies a less expensive reproductive assurance strategy. However, because open, insect-pollinated flowers (chasmogamous, CH) have the potential capacity to outcross via pollinators, CH progeny produced at any site should outperform selfed CL progeny. We evaluate the effect of fire frequency on the relative production of CL/CH flowers and fruits, and their seed set, along with several progeny performance parameters in Cologania broussonetii (Fabaceae), a resprouting herb with dimorphic cleistogamy native to the Chaco Serrano. Fire frequency increased cleistogamy expression, reaching extreme levels in high fire frequency sites. Seed set was similarly high for both CH and CL flowers in the unburned condition, while in burned sites the few developed CH flowers set more seeds than CL flowers. However, progeny performance was similar between CH and CL progeny at each and across all fire frequency conditions. Cleistogamy expression in C. broussonetii is maximized in abiotically degraded frequently burned habitats, although the selfed CL progeny is as successful as potentially outcrossed CH progeny. Fire frequency may decreased floral size and abundance, selecting for autogamous reproduction, which restricts not only the genetic potential of plant populations but also the resources offered to pollinators. At the community level, increased cleistogamy expression may potentially have negative implications for non-cleistogamous, more outcrossing species surviving in frequently burned environments.

Single-step genomic evaluation of lambing ease in Australian terminal sire breed sheep

Context Australian sheep breeding values (ASBVs) for the categorical trait of lambing ease are routinely estimated by Sheep Genetics via a threshold model. This has been pedigree-only, and has not utilised genomic information. Aim The present study aimed to update the genetic evaluation model and parameters for lambing ease for terminal sire sheep (dominated by White Suffolk and Poll Dorset breeds). The model includes correlations with birthweight and gestation length. Cross-validation was used to determine the value of the improved models and the inclusion of genomic information. Methods New data-preparation pipelines were developed to accommodate improved data-filtering methods and contemporary group construction. Genetic parameters, including correlations among traits, were estimated using continuous and threshold models, with various combinations of effects in mixed animal models. Cross-validation of breeding values was performed against progeny performance, by using forward prediction. Key results The increased volume of data, improved data preparation steps and enhanced evaluation software now allow a more complex model to be fitted, including maternal, sire by flock-year and genetic group effects, which were significant for all traits, along with the inclusion of multiple sire groups in the pedigree. However, the inclusion of the direct-maternal covariance and sire by flock-year terms resulted in unrealistically inflated estimates of some components, and thus the final covariance matrices required some adjustments. Cross-validation of breeding values was performed against progeny performance using forward prediction. For all traits, the phenotype accuracies and estimated breeding value correlations were higher from the new model without genomics than were those from the current routine evaluation. The benefit from including genomic information based on cross-validation is minimal currently but is expected to improve as the size of the reference population grows. Further work is required to define acceptable data-quality thresholds for the construction of datasets for routine breeding value estimation. Conclusions The new model and parameters resulted in ASBVs with an improved predictive ability, with increased accuracy and reduced bias compared with the current analysis. Furthermore, a small increase in accuracy was observed for all traits from utilising genomic information in the model. Implications The new genetic evaluation procedures and models will be used to update those being applied in the routine Sheep Genetics evaluation system and also support further index development for the terminal sire breeds in Australia.

Vitality in relation to litter size of crossbred pigs and the effect of the terminal sire line

Context Most research on sire lines is linked to growth and carcass traits. Only a limited number of field trials explore the effect of sire line on piglet vitality, litter size and the interactions between these traits. Aim The aim of this study was to examine the effect of sire line on the growth performance and vitality of progeny from birth to weaning and to evaluate the lines with respect to their impact on litter size. Methods Data included 150 litters of a Synthetic sire line (A) and 154 of a Piétrain sire line (B), with 4209 piglets born alive, which resulted from matings to 337 dams (Camborough PIC). The numbers of total born and born alive piglets per litter were recorded. Within 24 h after birth, piglet individual birthweight (BWbirth), sex (male/female) and body temperature (BT) were also recorded. At weaning, mortality rates and weaned pigs per sow were registered. At the day of weaning, 665 randomly chosen pigs were individually weighed. Weaning weights (WW) were used to calculate the weaning average daily gain (WADG). Key results Sire line significantly affected number of total born (P &lt; 0.0001), number born alive (P &lt; 0.01) and number of weaned pigs per sow (P &lt; 0.01). Across lines, each additional piglet per litter resulted in a 31.2 g decline in BWbirth (P &lt; 0.001). Larger litter sizes, higher BWbirth (P &lt; 0.01) and piglets with a lower BT (P &lt; 0.0001) were detected in litters of Sire line B compared with litters of Sire line A. No differences between lines were detected for WADG, WW and pre-weaning mortality (P &gt; 0.05). A positive correlation between birthweight and WW resulted in a correspondingly higher WADG (P &lt; 0.0001). Overall, heavier BWbirth piglets had a higher BT (P &lt; 0.0001). Conclusions The present study indicates that Sire line B would offer a possibility to maintain litter size at a high level and, simultaneously, achieve higher BWbirth, with consequently more vital piglets. Implication It is important to emphasise that further selection for litter size in dam lines is not indicated in terms of animal welfare but also production efficiency. Instead, it seems feasible to follow the above strategy and stabilise litter size at a high level, while at the same time breeding for vitality and survivability in sire lines.

Within-breed selection is sufficient to improve terminal crossbred beef marbling: a review of reciprocal recurrent genomic selection

Reciprocal recurrent selection is the selection of purebreds for crossbred performance and takes advantage of additive and non-additive variance by using pedigreed progeny performance records. Developed in maize, the adoption of this approach in livestock breeding has been limited to the pork and poultry industries; genomic selection may facilitate its extension into the beef industry by replacing pedigree. The literature regarding the relative importance of additive versus non-additive variance and reciprocal recurrent genomic selection models was reviewed. The potential for using reciprocal recurrent genomic selection in a terminal Wagyu × Angus cross scenario was examined. Non-additive variance is more important for fitness traits and accounts for a small proportion of variance related to production traits such as marbling. In general, reciprocal recurrent selection was not significantly better at improving performance of crossbreds than was traditional selection within parental breeds using only additive variance in the studies examined. Simulation studies showed benefits of including dominance or breed-specific allele effects in prediction models but advantages were small as more realistic simulations were examined. On the basis of the evidence, it is likely that in a terminal two-way cross-beef scenario utilising Wagyu sires and Angus dams, where selection emphasis is on marbling, selection of purebreds on the basis of additive variance will allow substantial progress to be realised.

High broodstock fads2 expression combined with nutritional programing through broodstock diet improves the use of low fishmeal and low fish oil diets in gilthead seabream (Sparus aurata) progeny

One of the factors that limits the replacement of fish meal (FM) and fish oil (FO) by plant ingredients in diets for marine fish, is their lack of long chain-polyunsaturated fatty acids (LC-PUFA). LC-PUFA are essential fatty acids for these fish species, which lack sufficient fatty acyl desaturase 2 (Fads2) activity to synthesize them. Nutritional programing or the use of broodstock with a higher Fads2 activity could improve marine fish ability to synthesize LC-PUFA and their ability to use low FM and FO diets. The aim of this study was to determine the effect of gilthead seabream broodstock with inherently high or inherently low fads2 gene expression and nutritional programing with broodstock diets rich in FO or rapeseed oil (RO) on the progeny growth performance, liver morphology, biochemical composition and expression of selected genes. Sea bream juveniles (2.31± 0.01 g initial body weight, mean ± SD) obtained from broodstock with either high (H) or low (L) fads2 expression and fed a broodstock diet based on FO or RO were randomly distributed into 12 × 250 L tanks and nutritionally challenged for 45 days with a diet containing only 7.5% FM and no FO. The highest growth was found in juveniles from broodstock with a high fads2 expression and fed the RO diet, whereas the lowest growth was obtained in those from broodstock with a low fads2 expression and fed the RO diet. Juveniles from broodstock with high fads2 expression showed significantly higher fads2 expression in liver and increased PUFA contents in liver and muscle. Replacement of FO by RO in broodstock diets led to a significantly increased hepatic 18:3n-6/18:2n-6 ratio and reduction in the viscerosomatic index of the progeny juveniles, the hepatocyte size and the ghr-1/ghr-2 expression in muscle. Overall, the results showed significant trans-generational effects of both the broodstock fads2 expression and the type of lipid in the broodstock diet on the metabolism and performance of the juvenile progeny challenged with a diet low in FM and FO.

Genetic parameters, prediction, and selection in a white Guinea yam early-generation breeding population using pedigree information.

Better understanding of the genetic control of traits in breeding populations is crucial for the selection of superior varieties and parents. This study aimed to assess genetic parameters and breeding values for six essential traits in a white Guinea yam (Dioscorea rotundata Poir.) breeding population. For this, pedigree‐based best linear unbiased prediction (P‐BLUP) was used. The results revealed significant nonadditive genetic variances and medium to high (.45–.79) broad‐sense heritability estimates for the traits studied. The pattern of associations among the genetic values of the traits suggests that selection based on a multiple‐trait selection index has potential for identifying superior breeding lines. Parental breeding values predicted using progeny performance identified 13 clones with high genetic potential for simultaneous improvement of the measured traits in the yam breeding program. Subsets of progeny were identified for intermating or further variety testing based on additive genetic and total genetic values. Selection of the top 5% progenies based on the multi‐trait index revealed positive genetic gains for fresh tuber yield (t ha−1), tuber yield (kg plant−1), and average tuber weight (kg). However, genetic gain was negative for tuber dry matter content and Yam mosaic virus resistance in comparison with standard varieties. Our results show the relevance of P‐BLUP for the selection of superior parental clones and progenies with higher breeding values for interbreeding and higher genotypic value for variety development in yam.

Effects of increasing dietary zinc sulfate fed to primiparous ewes: I. Effects on serum metabolites, mineral transfer efficiency, and animal performance

ABSTRACT Objective The objective of this research was to determine the effects of increasing Zn concentrations during late gestation on serum metabolites, serum mineral element transfer efficiency ratios (TE), and ewe and lamb performance in a semi-extensive management system. Materials and Methods Commercial white-face (WF; n = 23) and black-face (BF; n = 24) ewes (age ≈18 mo; BW 87.48 ± 8.37 kg) were sorted into breed-type groups and within groups ranked by BW and randomly divided into 3 dietary supplement treatment groups along the rank: CON (n = 13, 40 mg/kg Zn, ≈1 × NASEM recommendations), Zn500 (n = 19, 500 mg/kg Zn, ≈4 × NASEM recommendations), and Zn1000 (n = 15, 1,000 mg/kg Zn, ≈7 × NASEM recommendations). Treatments were administered in pelleted alfalfa (0.45 kg/ewe per day) fortified with Zn sulfate to increase Zn concentrations fed from 87.5 ± 8.9 d of gestation until parturition. Results and Discussion Maternal treatment did not affect ewe BW change throughout the experiment, nor serum metabolites, mineral element TE, or progeny performance through weaning (P ≥ 0.06). However, ewe greasy fleece weight the following year was greater for Zn500 than Zn1000 ewes (4.13 ± 0.18 kg vs. 3.48 ± 0.19 kg; P = 0.03) but did not differ between CON and the other treatments (3.68 ± 0.22 kg; P ≥ 0.22). The most marked effects were observed between breeds where Zn TE of WF ewes and lambs (264.3 ± 23.2) was approximately twice that of BF ewes and their lambs (165.4 ± 19.7; P Implications and Applications The results suggest feeding Zn supplemented from Zn sulfate beyond current NASEM recommendations from d 87 of gestation until parturition had minimal beneficial effects on fine-wool or meat-type ewes and lambs. Breed differences observed in serum mineral element concentrations (Fe and Zn) and related TE of the neonatal lamb may provide insights into adaptive trace mineral supplementation strategies based on breed type and related levels of production.

PSIX-5 Fetal programming in an industry applied setting – Effects of feeding methionine during late gestation on progeny performance, feed efficiency, and carcass quality for feedlot steers

Abstract The objective of this study was to assess if rumen-protected methionine supplementation during gestation would impact male offspring performance and carcass quality in an applied setting. Sixty-seven gestating cows were randomly assigned to control (CON), or methionine (MET) treatments. Cows had ad libitum access to hay from a round bale feeder and were fed once daily in a bunk for approximately eight weeks prior to calving either: 0.75 kg/head/d of supplement pellet supplying 12 g rumen-protected MET/cow/d, or identical pellet with no added MET. The 34 steer progeny (MET n = 18; CON n = 16) were transported to a feedlot, assigned to one of seven pens by weight and fed a corn-based grower diet (58% corn silage, 26% alfalfa haylage, 15% soybean meal) for 47 days, followed by a finisher diet (78% high moisture corn, 12% alfalfa haylage, 8% soybean meal) for 115±31.5 days until slaughter. Body weights were recorded biweekly. Organ weights were recorded at slaughter. Carcass quality, meat quality, and rib composition were recorded 24 to 48 hours after slaughter. Data were analyzed using PROC GLIMMIX in SAS, with treatment as the fixed effect, and pen as the random effect. Supplementation of MET during pregnancy increased weaning weight (MET: 311, CON: 291 ±14.8 kg; P ≤ 0.001), final weight (ME: 668, CON: 631 ±16.8 kg; P = 0.01), and individual dry matter intake (MET: 13, CON: 12 ±0.5 kg/d; P = 0.04) during the finishing phase. There was no effect of maternal methionine supplementation (P ≥ 0.05) for average daily gain. Hot carcass weight was greater for MET steers (MET 372 vs. CON 353 ±9.5 kg; P = 0.03), while organ weights and carcass quality were not affected (P ≥ 0.05) by MET supplementation. This study showed that supplementing methionine during late gestation in an industry applied setting improved some offspring performance measures but did not result in enhanced carcass quality.

PSIX-4 Fetal programming – Maternal plane of nutrition effects on progeny performance, feed efficiency, and carcass quality for feedlot steers

Abstract To evaluate if maternal supplementation of protein and rumen-protected methionine during late gestation affects steer progeny performance and carcass quality, 138 Angus X cows were used in a 3 x 2 factorial arrangement of treatments. Cows were randomly assigned one of three protein treatments (feeding to meet 90%, 100%, or 110% of metabolizable protein (MP) requirements), with(without) 9 g/d of rumen-protected methionine (MET) and fed these isocaloric diets for ~8 weeks before parturition. Steer progeny (n = 56) were assigned to one of seven pens by weight and received a common corn-based grower diet (58% corn silage, 26% alfalfa haylage, 15% soybean meal) for 47 days, followed by a finisher diet (78% high moisture corn, 12% alfalfa haylage, 8% soybean meal) for 115±31.5 days until slaughter. Body weights were recorded biweekly. Monthly ultrasound images of back and rump fats were captured. Organ weights were recorded at the time of slaughter, with carcass and meat quality recorded 24 to 48 hours later. Data were analyzed using PROC GLIMMIX in SAS, with maternal treatment as the fixed effect, and pen as the random effect. Feeding to meet 90% MP requirements resulted in heavier calf weaning weights compared to 100% and 110% (262, 251, and 245 ±13.9 kg, respectively; P = 0.01). Maternal nutritional treatment did not affect average daily gain, dry matter intake, feed conversion during finishing or organ weights. Increasing dietary MP content from 90%, 100% to 110% reduced grade fat thickness (15.5, 14.7, and 11.8 ±1.11 mm, respectively; P = 0.04) and yield grades (2.7, 2.9, and 2.3 ±0.17, respectively; P = 0.04), but increased lean meat yield (49.5, 49.4, and 50.6 ±0.3%, respectively; P = 0.04). These data suggest that maternal MP content may alter steer progeny carcass traits while maintaining animal performance during the finishing period.