Progeny Performance Research Articles

Beef heifer weight loss during gestation and its effects on progeny performance

The objective of the present study was to evaluate the intensity of weight loss in beef heifers during gestation and its effects on progeny performance up to 205 days of age. Sixty pregnant heifers aged 3 or 4 years, born between 2015 and 2017, from the rotational cross between Charolais and Nellore breeds were used. Females were divided according to the intensity of weight loss in the gestation period (7, 14, and 21%) and age at first calving (3 and 4 years), in a completely randomized design in a 3 x 2 factorial scheme. Lost up to 21% (T21) of body weight during gestation and had higher body conditions at the end of the breeding season (3.12 vs 3.02 and 3.04 points) and lower body weight at calving (341.96 vs 386.26 and 362.95 kg) about T7 and T14 heifers. The birth weight of the calves showed a tendency to increase as the weight loss of the pregnant heifers increased, with values of 29.46, 30.60 and 32.76 kg for treatments T7, T14 and T21, without reflections on the post-weaning performance of the progeny. In general, the loss of 14 or 21% of the heifer's body weight during pregnancy reduces the weight at the first calving, while heifers calved at 4 years of age are heavier and give rise to progeny with greater productive potential up to 205 days of age.

Consequence of cyclic pollen selection for heat tolerance on the performance of different generations in maize (Zea mays L.)

The reproductive stage in many crops, including maize, is very sensitive to heat stress and the genetic overlap between gametophytic and sporophytic phase gives an opportunity to select superior stress tolerant genotype at gametophytic stage. An attempt was made to evaluate the response of cyclic pollen selection in the F1 and F2 generations on the performance of F3 generation progenies for seed yield and yield contributing traits under natural heat stress conditions. In this direction three groups of F3 progenies, namely (i) pollen selection in F1 and F2 generations (GG), (ii) pollen selection only in F2 generation (CG), (iii) no pollen selection in F1 and F2 generations (CC) were screened for heat stress at Agricultural Research Station (ARS), Bheemarayanagudi. The GG progenies recorded significantly higher chlorophyll content, more number of pollen grains per anther and less pollen sterility compared to CG and CC group of progenies under heat stress. Further, the F4 progenies obtained through cyclic pollen selection (in F1, F2 and F3) were also tested for heat stress tolerance at seedling stage. The significant improvement for heat stress tolerance was recorded in F4 progenies derived through cyclic pollen selection as compared to control (no pollen selection for heat tolerance in any generation) F4 progenies. The results indicated that cyclic pollen selection in F1, F2 and F3 generations improved the heat stress tolerance of the progenies in the succeeding generations. To provide genetic evidence for the effect of pollen selection for heat tolerance, the control F2 (C) and selected F2 (G) populations were compared for the segregation of SSR markers. The selected F2 (G) population showed significant deviation from normal Mendelian ratio of 1:2:1 and showed skewness towards the alleles selected from male parent. The results provide strong evidence for an increase in the frequency of parental alleles in the progenies that impart heat stress tolerance.

Improved offspring performance of broiler breeder hens fed amino acid complexed trace minerals

The present study aimed to evaluate the effects of partial substitution of inorganic trace minerals ( ITM ) by amino acid complexed minerals ( AACM ) on broiler breeder hens’ performance and offspring. A total of 640 Cobb 500 broiler breeder hens, 22 wk of age, were allocated to four dietary treatments: T1- (Control) contained ITM forms of Zn, Mn, Cu, Fe and Se at 100, 100, 10, 50 and 0.30 ppm, respectively; T2- (Partial replacement) of Control by AACM Zn, Mn, Cu, and Se at 60, 60, 3, and 0.15 ppm of ITM, and 40, 40, 7, and 0.15 ppm of AACM, respectively.; T3- (Partial replacement) of Control, same as T2 but with Fe at 10 and 40 ppm of ITM and AACM, respectively; T4- (On Top) supplementation of Zn, Mn, Cu, Se and Fe (T1+T3). Laying production was evaluated from 26 to 66 wk, whereas egg quality was evaluated at 35, 45, 55, and 65 wk of age. At each period, eggs were incubated and evaluated for hatchability parameters and chick quality. At 66 wk of age, eggs were incubated to obtain 800-day-old male chicks for the progeny performance trial. Total and settable egg production and incubation parameters were not affected by supplementation treatments (P > 0.05). Eggshell breaking strength significantly increased (P < 0.05) in the On Top supplementation group compared to the Control. The offspring from hens fed partially Zn, Mn, Cu, Se and Fe AACM had higher body weight gain ( BWG ) in the first week (P < 0.05) and maintained a smaller feed conversion ratio ( FCR ) from 1 to 35 d compared to the offspring of Control ITM group (P < 0.05). Maternal AACM supplementation increased offspring BWG and FCR from 1 to 7 d and 1 to 35 d, respectively.

Per se performance of matromorphic progenies (Mat3) and their parental lines in garden pea (Pisum sativum L.) under subtropical conditions of J&amp;K

Matromorphs or maternals are non-hybrid diploid offspring which originate entirely from the maternal parent and facilitate in obtaining instant homozygous lines from heterozygous base population thereby, shortening the time requirement of conventional breeding method for the production of homozygous lines. Per se performance of twelve advanced generations of matromorphs (Mat3) along with their ten parental lines were evaluated for growth, yield and screening against powdery mildew and rust disease under sub tropical conditions of Jammu &amp; Kashmir under the present study. A field experiment was carried out during the year 2020-2021 at the Experimental farm, SKUASTChatha, Jammu. On the basis of overall findings of the present research study, it was concluded that Palam Triloki was the earliest with minimum days to 50% flowering (44.00) followed by three matromorphic progenies viz., Palam Triloki (46.33 days), Palam Triloki x P-89 (44.67 days) and Palam Triloki x AP-1 (46.83 days). Regarding plant height, maximum plant height was recorded in parental line Arka Apoorva (90 cm) followed by Arka Ajit (89.50 cm) and Arka Apoorva x AP-1 (Pl.1) (88.50 cm) and Arka Apoorva x AP-1(Pl.2) (88.30 cm) amongst Mat3 progenies were found to be superior. Among Mat3, maximum number of seeds per pod were recorded in Arka Apoorva X P-89 (7.83) followed by Arka Apoorva x AP-1[Pl.2] (6.77) and P-89 (7.18) and Arka Apoorva (6.34) among parents. Maximum number of pod per plant were recorded in matromorphic progenies, Arka Apoorva x P-89 (45.89) followed by Arka Apoorva x AP-1[Pl.2] (44.61), Arka Apoorva x AP-1[Pl.1] (41.83) and among parental lines, P-89 (41.28), Arka Apoorva (35.83) had maximum number of pod. Maximum pod yield per plant was recorded in Arka Apoorva x P-89 (200.38g) followed by Arka Apoorva x AP-1 [Pl.1] (184.37 g) in Mat3 whereas among parental lines maximum pod yield was recorded in P-89 (174.76g) and Arka Apoorva (145.72g). Based on the screening of genotypes under study, Arka Apoorva x P-89 (Mat3) was identified as highly resistant genotype against major pea diseases i.e. powdery mildew and rust.

The Impact of Fetal Programming in Ewe Nutrition with Chromium Propionate or Calcium Salts of Palm Oil on the Meat Quality and Bone of the Progeny.

This study aimed to evaluate the inclusion of chromium propionate or calcium salts of palm oil in ewes' diet during the final third of gestation and lactation on progeny performance, carcass characteristics, non-carcass components, and bone density. Forty-three ewe, Santa Inês and Dorper breed, three ± one-year-old, and body weight 57 ± 10 kg were used. The experimental design was in casual blocks in three treatments, CTL treatment (n = 15) with starch from corn; CR (n = 15) diet CTL plus chromium propionate; PF (n = 13) diet CTL plus calcium salts of palm oil. After weaning, 23 male lambs from these ewes were confined in individual stalls, with the same diet for 60days, slaughtered. The data were analyzed using the SAS program, PROC GLM, and compared the means using Tukey's test at 5% probability. The maternal diet did not alter the dry matter intake, feeding efficiency, and average daily weight gain. Therefore, weights (weaning and slaughter) and carcass yield were higher for CR and PF groups than for CTL (P < 0.05). The treatment did not influence the loin eye area and fat thickness (P > 0.05). The spleen and the respiratory tract were smaller for PF and larger for CTL (P < 0.05). Leg weight was higher for CR. The perimeter and depth of the shank for the CR and PF lambs were higher, indicating an effect of maternal nutrition in this commercial cut. The CR group had a smaller epiphysis measurement and femur length than the CTL group. We concluded that the fetal programming effect in ewes fed with Cr propionate and Ca salts of palm oil benefited the progeny by increasing their body weight, better carcass yield, and a higher proportion of prime cuts.

Seed sources variation in growth traits of Grewia optiva (Beul)

The study was conducted to estimate genetic variability among different seed sources of Grewia optiva Drummond under field conditions in Himachal Pradesh, India. Seed source (S8) Barthi exhibited outstanding performance for growth parameters. Based on the progeny performance, genotypes S1G1 (Uncha-gaon), S2G3 (Gaddo), S3G2 (Jajjar), S5G2 (Bala) and S6G3 (Jinzkari) were found to be most promising for growth traits. The percentage of genotypic coefficient of variance (GCV) and phenotypic coefficient of variation (PCV) was recorded maximum for branch angle i.e., 40.56% and 40.65%, respectively. Percentage of phenotypic coefficient of variation observed higher than genotypic coefficient of variations for all the traits. Highly significant and positive genotypic and phenotypic correlation was observed in plant height with number of branches (rg=0.324, rp=0.317) and leaf area with basal diameter (rg=0.326, rp=.307). High heritability was reported for all growth traits. The highest genetic gain was recorded for branch angle (54.74) and moderate for leaf area (29.95). Genotypes were clustered into two distinct groups using hierarchical clustering analysis. The maximum inter- cluster distance was observed between S2G3 and S7G2, whereas, the maximum intra-cluster distance was observed between S2G3 and S8G3 in cluster I and S1G1 and S7G2 in cluster II. Principal components (PCI-PCIV) cumulatively accounted for 76.31% of total variation. The PCA I explained 23.18% of the total variance, associated with plant height, branch angle, basal diameter.

P169. Meta-analysis of the effects of inactivated Pichia guilliermondii yeast fed to sows on progeny performance before and after weaning

P169. Meta-analysis of the effects of inactivated Pichia guilliermondii yeast fed to sows on progeny performance before and after weaning

Performance of F1 progenies developed through crosses between Brassica carinata A. Braun A(♀) and Brassica rapa L (♂)

Performance of F1 progenies developed through crosses between Brassica carinata A. Braun A(♀) and Brassica rapa L (♂)

Microwave Soil Heating Promotes Strawberry Runner Production and Progeny Performance

Strawberry runners (transplants) in many regions of the world are produced in soils treated with chemical fumigants to control pathogens and weeds and meet phytosanitary requirements. Many fumigants, however, are under threat of withdrawal because of concerns over their impact on the environment (e.g., methyl bromide). The current study considered the use of microwaves for heat disinfestation of soil for field-grown runners for the first time. Results from two field experiments showed that microwave treatment reduced the survival of buried inoculum of the strawberry pathogens Fusarium oxysporum (by up to 93%) and Sclerotium rolfsii (by up to 100%) compared with untreated soil. Furthermore, the treatment reduced the subsequent growth of these pathogens in the laboratory by up to 82% and 100%, respectively. Microwave treatment also reduced the natural DNA concentration of Pythium spp. (clades I &amp; F) in soil by up to 94% compared with untreated soil. The effect of microwave against soilborne pathogens reduced as soil depth increased. Microwave treatment reduced the emergence of weeds in field soils by up to 65% and increased runner yields by 10–37%. The effect of microwave treatment on runner yield was greater when all soil was treated, rather than when strips of soil around the mother plants were treated. Results from complimentary pot experiments showed that early strawberry growth in the glasshouse was equivalent in soils treated with microwave or the fumigant methyl bromide/chloropicrin. Furthermore, the early performance of runners sourced from field soils treated with microwave or methyl bromide/chloropicrin was equivalent. Results from the pot experiments also showed that steam treatment required 10 times more energy per mass of soil to disinfest than microwave. The limitations of microwave in the current experiments are discussed, but the capacity for the technology to disinfest field soils in an energy-efficient manner demonstrates its potential for further development as an alternative to soil disinfestation with chemical fumigants.

Introgressing cry1Ac for Pod Borer Resistance in Chickpea Through Marker-Assisted Backcross Breeding.

The gram pod borer Helicoverpa armigera is a major constraint to chickpea (Cicer arietinum L.) production worldwide, reducing crop yield by up to 90%. The constraint is difficult to overcome as chickpea germplasm including wild species either lacks pod borer resistance or if possessing resistance is cross-incompatible. This study describes conversion of elite but pod borer-susceptible commercial chickpea cultivars into resistant cultivars through introgression of cry1Ac using marker-assisted backcross breeding. The chickpea cultivars (PBG7 and L552) were crossed with pod borer-resistant transgenic lines (BS 100B and BS 100E) carrying cry1Ac that led to the development of BC1F1, BC1F2, BC1F3, BC2F1, BC2F2, and BC2F3 populations from three cross combinations. The foreground selection revealed that 35.38% BC1F1 and 8.4% BC1F2 plants obtained from Cross A (PBG7 × BS 100B), 50% BC1F1 and 76.5% BC1F2 plants from Cross B (L552 × BS 100E), and 12.05% BC2F2 and 82.81% (average) BC2F3 plants derived from Cross C (PBG7 × BS 100E) carried the cry1Ac gene. The bioassay of backcross populations for toxicity to H. armigera displayed up to 100% larval mortality. BC1F1 and BC1F2 populations derived from Cross B and BC2F3 population from Cross C segregated in the Mendelian ratio for cry1Ac confirmed inheritance of a single copy of transgene, whereas BC1F1 and BC1F2 populations obtained from Cross A and BC2F2 population from Cross C exhibited distorted segregation ratios. BC1F1 plants of Cross A and Cross B accumulated Cry1Ac protein ranging from 11.03 to 11.71 µgg−1 in leaf tissue. Cry1Ac-positive BC2F2 plants from Cross C demonstrated high recurrent parent genome recovery (91.3%) through background selection using SSR markers and phenome recovery of 90.94%, amongst these 30% plants, were homozygous for transgene. The performance of BC2F3 progenies derived from homozygous plants was similar to that of the recurrent parent for main agronomic traits, such as number of pods and seed yield per plant. These progenies are a valuable source for H. armigera resistance in chickpea breeding programs.

Genetic parameters for resin production of Pinus merkusii progeny test collected from three landraces in Banyumas Barat Forest District, Indonesia

Abstract. Nugrahanto G, Na’iem M, Indrioko S, Faridah F, Widiyatno, Abdillah E. 2022. Genetic parameters for resin production of Pinus merkusii progeny test collected from three landraces in Banyumas Barat Forest District, Indonesia. Biodiversitas 23: 2010-2016. Pinus merkusii Jungh. et de Vriese is a native pine species in Indonesia that is used in the production of essential and economically valued products, such as wood and resin. The resin productivity can be increased significantly via breeding programs. The objective of this study is to analyze the genetic parameters of resin productivity based on the progeny performance in three landrace seeds sources, namely, Sumedang seedling seed orchards (SSOs), Jember SSO, and East Java seed source. The drilling method was used for tapping trees, and then resin production was measured individually. Additional data on height, diameter, and branch-free height were also collected. Based on family variance component analysis data of resin production, it was noted that Sumedang SSO, Jember SSO, and East Java seed sources have relatively high genetic variations of 4.48%, 15.77%, and 3.80%, respectively. These values were then followed by a moderate family heritability value for all of them (0.451-0.551). A high value of individual heritability estimates was obtained for Jember SSO (0.658), and moderate values were found for Sumedang SSO (0.182) and East Java seed sources (0.158), respectively. The estimated genetic gains were calculated for resin production using selection intensity levels at 10%, 25%, and 50%. The result indicated that the Jember SSO landrace obtained the highest genetic gains at 17.55%, 12.73%, and 7.99%, for the above-mentioned intensity levels, respectively. In contrast, the lowest one was found in the Sumedang SSO landrace.

Coffea arabica rootstock resistant to Meloidogyne paranaensis nematodes

AbstractMeloidogyne paranaensis is a species of root‐knot nematode that affects coffee (Coffea arabica L.) tree growth by causing severe damages to the plant root. This study evaluated the agronomic performance of Coffea arabica progenies in an M. paranaensis‐infested field and assessed the compatibility of resistant C. arabica genotype 28‐I‐4 (GEN28) as rootstock for susceptible cultivars. Experiment 1: under field conditions, six progenies were analyzed; the controls were ‘IPR100’ as resistant and ‘Catuaí Vermelho IAC 144’ (CtV144) as susceptible. Experiment 2: under greenhouse conditions, combinations of grafts and rootstocks between susceptible CtV144 and GEN28 were evaluated regarding their resistance to M. paranaensis alongside their noninoculated counterparts. For this, M. paranaensis reproduction factor (RF), total population of the nematode per gram of root system, growth parameters, gas exchange, and water potential (ψpd) were evaluated. In Experiment 1, resistant C. arabica progenies were more vigorous, productive, and showed a population of M. paranaensis threefold‐times lower than that observed in roots of susceptible CtV144. Among the resistant progenies selected in the field experiment, GEN28 was chosen for physiological compatibility study with the traditional cultivar CtV144. In Experiment 2, the CtV144 grafted onto GEN28 led to resistance to M. paranaensis, as well as a higher leaf area and ψpd as compared with nongrafted CtV144. Therefore, the GEN28 holds suitable characteristics to be used as a new Coffea arabica rootstock applied to production of resistant seedlings to Meloidogyne paranaensis nematodes. This technology represents an alternative to keep up coffee activity in infested areas.

125 Utilization of Performance-tested and NSIP Sires Improved Progeny Performance and Value in Ram Test Program

Abstract Sire selection can have long-term impacts on flock performance. The objective here was to evaluate the effect of performance-tested and/or NSIP rams on progeny performance and value in a ram test program. Rams (Katahdin = 104, Dorper = 7, Texel = 3, Cheviot = 3) were delivered to the Southwest Virginia Agricultural Research and Extension Center (SWAREC) Ram Test on June 1. Ram pedigrees were obtained from consignors and rams were classified based on whether their sires were tested in a previous SWAREC Ram Test (TESTED), enrolled in the National Sheep Improvement Program (NSIP), or neither TESTED nor NSIP (NEITHER). Some sires (16%) were previously tested and enrolled in NSIP. Rams were dewormed and rested for two weeks. On June 22, rams were given Haemonchus contortus larvae adjusted for body weight (average = 5000 L3). FAMACHA scores and fecal egg counts (FEC) were monitored every two weeks until August 31. Rams were dewormed based on FAMACHA ≥ 3. Select rams were sold at auction as breeding stock. Statistical analysis were performed using SAS (SAS Institute, Cary, NC). Rams requiring deworming had greater FAMACHA scores and FEC at all time points (P &amp;lt; 0.05), despite not requiring treatment until August 17 (5%) and August 31 (12%). In total, 17% of rams were dewormed. Of the dewormed rams, a smaller portion of rams sired by TESTED rams (10%) and NSIP rams (15%) required treatment compared to rams sired by NEITHER rams (85%; P &amp;lt; 0.05). Rams sired by TESTED and NSIP rams had a higher average value than those sired by NEITHER rams ($2070 and $1838, respectively, vs. $1078; P &amp;lt; 0.05). Selection of sires that are TESTED and/or NSIP resulted in progeny that had a lesser chance of requiring treatment and sold for greater value.

Effects of Age at First Joining and Ewe Genotype on the Performance of Two-Tooth Ewes and That of Their Progeny to Slaughter.

Simple SummaryEwe replacements are a major cost in prime-lamb production. Many producers do not join replacements at 7 months as they believe that it has a negative effect on two-tooth performance. The effect of age at first joining on the reproductive performance of two-tooth ewes, representing three genotypes, was evaluated as well as the performance of their progeny. Whilst joining at 7 months reduced ewe body weight when joined at 19 months and immediately post joining, body weight at the subsequent lambing was increased, and ewe productivity and progeny performance were unaffected. Ewe genotype significantly influenced litter size and the number of lambs reared per ewe joined but had no effect on progeny performance. The probability of rearing at least one lamb (PR1L) is an indicator of overall efficiency. In the current study, whilst there was no relationship between ewe body weight when joined at 19 months and PR1L, there was a positive relationship between body weight at 7 months and PR1L at 2 years. It is concluded that joining replacements at 7 months does not have a negative impact on the performance of two-tooth ewes. The effects of first-joining age (7 or 19 months) and genotype on ewe performance when joined to lamb at 2 years, and the performance of their progeny, were evaluated using 424 ewes, representing 3 genotypes: Belclare (Bel), Suffolk × Belclare (Suf × Bel) and Suffolk-type (≥75% Suffolk ancestry (Suf75)). Ewes were managed in a grass-based system. Ewes first joined at 7 months were lighter (p < 0.01) at 19 months and immediately post lambing; otherwise, age at first joining had no effects (p > 0.05) on ewes or their progeny and there were no important interactions with genotype. Bel and Suf × Bel had larger litters (p < 0.001) and reared more lambs per ewe joined (p < 0.01) than Suf75. Ewe genotype had no effect (p > 0.05) on proportion failing to lamb, incidence of lambing assistance, lamb mortality, ewe survival to 31 months, or progeny performance. Increasing the body weight of ewes at 7 months of age increased the probability (p < 0.02) of rearing 1 or more lambs at 2 years and there was no interaction with genotype. It is concluded that age at first joining had no negative impact on the performance of ewes or their progeny.

Reduced vitamin supplementation with fat-soluble vitamins A, D, and E added at National Research Council requirements may not be adequate for optimal sow and progeny performance

Objective: To evaluate performance and physiological vitamin status of sows and progeny fed 2 vitamin supplementation levels, industry vs reduced (all vitamins reduced with fat-soluble vitamins added at National Research Council recommendations). Materials and methods: Sows (n = 244) were allotted in a randomized complete block design to 1 of 2 vitamin supplementation levels. At weaning, 765 progeny from a subset of sows were allotted to treatments in a 2 × 2 factorial arrangement of two sow and two nursery vitamin supplementation levels with 15 pens/treatment. Performance and vitamin status of sows and progeny were measured from farrowing to nursery exit. Results: Reduced vitamin supplementation reduced sow lactation feed intake (P = .01), hepatic vitamin A (P = .001), and serum vitamin D (P &lt; .001), but did not affect sow body weight or litter performance. Regardless of vitamin levels fed to the sow, progeny fed reduced levels post weaning had decreased circulating (P &lt; .001) and stored (P = .03) vitamin levels and a reduction in average daily gain (P &lt; .001), average daily feed intake (P &lt; .001), gain:feed ratio (P = .002), and body weight (P &lt; .001) at the end of the nursery period compared to progeny fed industry levels. Implications: Reduced vitamin supplementation reduced sow feed intake without affecting sow or litter performance, but decreased circulating and stored vitamin levels in sows could impact long-term reproductive performance. Reduced vitamin inclusion levels in nursery diets reduced performance and serum vitamin concentrations compared to industry vitamin levels.

Influence of Maternal Protein Restriction in Primiparous Beef Heifers during Mid- and/or Late-Gestation on Progeny Feedlot Performance and Carcass Characteristics.

Simple SummaryMaternal nutrient restriction in beef cows can impact developmental processes in the fetus, which may influence lifetime performance. If feed is limited, a maternal deficiency in protein and/or energy can occur. As a result, the fetus may receive inadequate levels of nutrients, potentially altering fetal development. In the present study, we evaluated the impact of a metabolizable protein restriction during mid- and/or late-gestation on progeny carcass characteristics. First-calf heifers were provided with a diet that either met their metabolizable protein requirements or caused an 80% restriction in metabolizable protein during mid- and/or late-gestation in a crossover design. Our results suggest that heifers catabolized lean body tissue, but not body fat stores, to overcome the metabolizable protein deficiency. However, restricting metabolizable protein in gestating heifers did not substantially influence the feedlot performance or carcass characteristics of their offspring. The restricted dams may have buffered their offspring from the metabolizable protein limitation during gestation.This study investigated the impacts of metabolizable protein (MP) restriction in primiparous heifers during mid- and/or late-gestation on progeny performance and carcass characteristics. Heifers were allocated to 12 pens in a randomized complete block design. The factorial treatment structure included two stages of gestation (mid- and late-) and two levels of dietary protein (control (CON); ~101% of MP requirements and restricted (RES); ~80% of MP requirements). Half of the pens on each treatment were randomly reassigned to the other treatment at the end of mid-gestation. Progeny were finished in a GrowSafe feeding system and carcass measurements were collected. Gestation treatment x time interactions indicated that MP restriction negatively influenced heifer body weight (BW), body condition score, and longissimus muscle (LM) area (p < 0.05), but not fat thickness (p > 0.05). Treatment did not affect the feeding period, initial or final BW, dry matter intake, or average daily gain of progeny (p > 0.05). The progeny of dams on the RES treatment in late gestation had a greater LM area (p = 0.04), but not when adjusted on a hot carcass weight basis (p > 0.10). Minimal differences in the animal performance and carcass characteristics suggest that the level of MP restriction imposed during mid- and late-gestation in this study did not have a significant developmental programming effect.

Weight at conception and gestational gains in the efficiency of beef cows and progeny performance.

The aim of this study was to evaluate the effects of conception weight and gestational weight gain on performance and productive efficiency in beef cows and their calves. Eighty-eight primiparous, three-year old Braford females were used, divided according to weight at conception and gestational performance (High and Low): cows with a low conception weight and low gestational weight gain (LL), cows with low conception weight and high gestational weight gain (LH), cows with high conception weight and low gestational weight gain (HL), and cows with high conception weight and high gestational weight gain (HH). At calving, HH cows were heavier than LH and HL and these were heavier than LL cows. Male calves born to HH cows were superior in body weight to those born to LL cows at 150, 210 and 365 days. Female calves born to HH, HL or LH cows were superior to those born to LL cows in pregnancy at 14 months of age. The LL and HL cows were more efficient in calf production. Actual fertility was influenced by the nutritional level of the herd, where HH cows were superior than LL cows. Better cow herd nutrition increases the development and performance of the progeny.

Investigation of methods for inclusion of systematic environmental effects in weaning and post-weaning weights for meat sheep in large-scale genetic evaluation

Context Genetic evaluation of Australian sheep is conducted for millions of animals for more than 100 traits. Currently, the Australian sheep genetic-analysis software (OVIS) applies a pre-adjustment of phenotype for fixed effects rather than fitting all fixed and random effects jointly in a linear mixed model to estimate breeding values. However, the current correction factors might be outdated and potential interactions among fixed effects not accounted for, which could lead to bias in estimated breeding values (EBVs). Aims This study aimed to assess whether correction factors used in OVIS for early bodyweights recorded in meat sheep breeds are appropriate, so as to explore whether the pre-adjustment method is still suitable and how this compares with a linear mixed model, and to estimate the significance of interactions between fixed effects. Methods Correlations between EBVs from different models and regression slopes from forward prediction were calculated, using weaning-weight data on 365 956 White Suffolk and 370 649 Poll Dorset sheep and post-weaning weight data on 292 538 White Suffolk and 303 864 Poll Dorset sheep. Key results The current OVIS procedure resulted in regression slopes of progeny performance on sire EBVs (averaged over breeds) of 0.37 and 0.35 for weaning and post-weaning weights respectively. Updated pre-adjustment factors improved the regression slopes to 0.40 and 0.38 respectively. Analysis with a linear mixed model produced significantly better regression slopes than did pre-adjustment (0.47 and 0.44 respectively). Further, regression slopes obtained from the linear mixed model with flock by sex by age interaction averaged over breeds were 0.48 for weaning and 0.46 for post-weaning weight respectively, which was a moderate improvement over the current OVIS model. Including a flock by sex by age interaction produced significantly better improvement in Poll Dorset sheep and modest improvement in White Suffolk sheep than did linear mixed model without interaction. Conclusions Using a linear mixed model with a flock by sex by age interaction significantly improves the utility of estimated breeding values for weaning and post-weaning weight in predicting the performance of future progeny. Implications To account for systematic environmental effects, a linear mixed model should be used in OVIS to jointly estimate the fixed effects and EBVs.

A meta‐analysis of combining ability effects in wheat for agronomic traits and drought adaptation: Implications for optimizing biomass allocation

AbstractCombining ability effects for yield related traits can serve as selection criteria to pursue breeding for optimal biomass allocation in wheat (Triticum aestivum). The objective of this paper is to provide information based on a retrospective quantitative genetic analysis on combining ability studies of wheat for yield and yield‐related traits to predict potential genetic gains achievable in improving biomass allocation for drought tolerance and soil carbon storage. The study compares data on the general combining ability and specific combining ability effects of wheat for yield and related traits under optimum and drought stressed conditions from 40 studies around the world. Days to heading (DTH), plant height (PH), number of tillers per plant (TN), kernels per spike (KPS), 1,000‐kernel weight (TKW), shoot biomass (SB), and grain yield (GY) exhibited wide variation for general combining ability (GCA) and specific combining ability effects. Progeny performance increased by 14.30 and 4.04% for SB and GY, respectively, compared with parental values under optimum water conditions. Number of tillers and SB exhibited positive associations with GY (.45 ≤ r ≤ .85, p &lt; .05) under both water conditions. Meta effect sizes for drought stress were negative. The highest meta‐effect sizes were calculated for DTH (−4.5) followed by SB (−2.0), whereas KPS (−1.25) had the lowest. The genetic gains for PH, SB, and other yield components showed that divergent crosses involving complementary parents could enhance biomass allocation patterns in wheat. This could be used as a basis for improving biomass allocation to roots.

Feeding Sows Lucerne, or Diets with Similar Energy and Nutritional Profiles to Lucerne, Improves the Pre-Weaning Performance of Piglets

Feeding fibre and branched-chain amino acids (BCAA) to sows during late gestation and lactation, respectively, have been shown to improve litter weights at weaning. Therefore, supplementing primiparous sow diets with lucerne chaff, a feedstuff high in fibre, BCAA and tryptophan, may improve the performance of their progeny. Experiment 1 investigated the effects of feeding primiparous sows (n = 118) either (i) a control diet (CON); (ii) CON with 1 kg of lucerne chaff (LUC); or (iii) a diet formulated to have a similar digestible energy and BCAA content as CON + LUC (SIMLUC 1) until farrowing. The LUC and SIMLUC 1 diets improved day 21 litter weight (p = 0.055). In Experiment 2 primiparous (n = 111) and multiparous sows (parities 2–5, n = 112) were fed either the CON or SIMLUC diet (SIMLUC 2) from day 110 of gestation to farrowing (PreF), or to day 10 post-farrowing (PreF + PostF). The SIMLUC 2 diet tended to be more beneficial to primiparous compared to multiparous sows when fed PreF, as indicated by an interaction between diet and parity on day 21 average piglet weights (p = 0.078). Overall, SIMLUC is most effective in improving primiparous progeny performance as evidenced by their D21 weights.