Weaning Body Weight Research Articles

The impact of cow size on cow-calf and postweaning progeny performance in the Nebraska Sandhills.

Optimizing beef production system efficiency requires an understanding of genetic potential suitable for a given production environment. Therefore, the objective of this retrospective analysis was to determine the influence of cow body weight (BW) adjusted to a common body condition score (BCS) of 5 at weaning-influenced cow-calf performance and postweaning steer and heifer progeny performance. Data were collected at the Gudmundsen Sandhills Laboratory, Whitman, NE, on crossbred, mature cows (n = 1,607) from 2005 to 2017. Cow BCS at calving, prebreeding, and weaning were positively associated (P < 0.01) with greater cow BW. Increasing cow BW was positively associated (P < 0.01) with the percentage of cows that conceived during a 45-d breeding season. For every additional 100-kg increase in cow BW, calf BW increased (P < 0.01) at birth by 2.70 kg and adjusted 205-d weaning BW by 14.76 kg. Calf preweaning average daily gain (ADG) increased (P < 0.01) 0.06 kg/d for every additional 100-kg increase in cow BW. Heifer progeny BW increased (P < 0.01) postweaning with every additional 100-kg increase in dam BW. Dam BW did not influence (P ≥ 0.11) heifer puberty status prior to breeding, overall pregnancy rates, or the percentage of heifers calving in the first 21 d of the calving season. Steer initial feedlot BW increased by 7.20 kg, reimplant BW increased by 10.47 kg, and final BW increased by 10.29 kg (P ≤ 0.01) for every additional 100-kg increase in dam BW. However, steer feedlot ADG was not influenced (P > 0.67) by dam BW. Hot carcass weights of steers were increased (P = 0.01) by 6.48 kg with every additional 100-kg increase in cow BW. In a hypothetical model using the regression coefficients from this study, regardless of pricing method, cow-calf producers maximize the highest amount of profit by selecting smaller cows. Overall, larger-sized cows within this herd and production system of the current study had increased reproductive performance and offspring BW; however, total production output and economic returns would be potentially greater when utilizing smaller-sized cows.

A Comparative Evaluation on Productive and Reproductive Traits of Tamworth X Desi and Hampshire X Niang Megha Pigs under Subtropical Hill Ecosystem in Eastern Himalayas Region of India

Background: Pig farming is the integral component of farming system in the tribal dominated North Eastern region of India since pork is the most preferred meat among tribal population. However, pork still remains deficit and a high supply-demand gap exists due to low productivity of nondescript local pigs. In this context, popularization of crossbred pigs is the suitable option to enhance productivity. Thus, the study was carried out to evaluate the performance of crossbred pigs viz., Tamworth X Desi (T and D), Hampshire X Niang Megha (H and NM) in order to improve the pig productivity in the region. Methods: Data was collected from crossbred pigs viz., Tamworth X desi (T and D), Hampshire X Niang Megha (H and NM) and Niang Megha (NM) pigs which is maintained in the Pig breeding farm of the institute. This data included the study of productive (n=778 piglets), reproductive (n =107 sows) and carcass traits (n =45 slaughters) over a period of about eight years (2005-2013) from the farm record books cum-pedigree sheet of the pig farm. The date was analyzed suitable statistical tools. Result: The study recorded no significant differences (P less than 0.01) in pre weaning body weight, growth rate and mortality rate between T and D and H and NM crossbred pigs however, both the crossbred pigs revealed significantly (P less than 0.05) higher pre weaning body weight and growth rate than that of NM pig. Post weaning body weight were significantly (P less than0.05) highest in T and D crossbred pigs followed by H and NM crossbred pig as compared to NM pigs at all age groups. Farrowing rate were significantly (P less than 0.05) highest in NM pigs and lowest in T and D crossbred pigs. However, farrowing interval were significantly (P less than0.05) highest in NM pig and lowest in H and NM crossbred pigs. Regarding litter size at birth and weaning, there was no significant (P less than0.01) difference between T and D and H and NM pig but both these pigs revealed significantly (P less than0.05) higher litter performance than NM pig. Back fat thickness and loin eye area were significantly highest in T and D pigs and lowest in NM pig. However, NM pig has significantly highest lean meat content than T and D and H and NM crossbred pig. There was no significant difference (P less than0.01) observed of dressing percentage between T and D and H and NM crossbred pig but, both the genetic group yield significantly (P less than0.05) higher dressing percentage than Niang Megha pigs. Based on the productive, reproductive and carcass traits, the study concluded that T and D pigs more suitable for fattener pig production due to their higher growth performance and carcass yield, whereas H and M pigs can be utilized for breeding purpose in subtropical hill ecosystem of Northeast India.

Association of GH polymorphisms with growth traits in buffaloes

Members of the somatotrophic axis, especially GH and IGF1, are essential for growth. The association between GH polymorphisms and growth traits was numerously studied in cattle; however, no data are available for such association studies in buffalo. Therefore, this study was conducted to screen for polymorphisms in the GH gene and to study their putative association with growth traits in 200 Egyptian buffaloes. Polymerase chain reaction single-strand conformation polymorphism and sequencing were applied to look for polymorphisms in 3 loci spanning all exons and introns of buffalo GH. The C (MspI+) >T (MspI-) SNP in intron3, which is well known in cattle, was not detected in the examined buffaloes. However, 2 missense mutations were detected in exon5: one previously detected p.Leu153Val SNP, with very low frequencies for the mutant (Val) allele and one novel p.Asn174His SNP. At weaning age, the p.Leu153Val SNP was significantly associated with weaning body weight and gain with the positive effect of the wild allele (Leu) and higher GH serum, mRNA, and protein levels in animals with Leu/Asn and Leu/His haplotypes. At yearling age, the 2 SNPs associated with yearling weight and gain with positive effect for the mutant (Val and His) alleles with increased GH, and IGF1 serum, mRNA, and protein and GHR mRNA and protein levels in animals with Val/Asn haplotype. Therefore, the selection of Egyptian buffaloes with the Val/Asn haplotype could improve the growth traits of Egyptian buffaloes at yearling age which is the target age for perfect growing.

Postweaning response on growth and nutrient digestion to using different weaning strategies when feeding moderate and high amounts of milk replacer to Holstein calves

Many changes occur in the rumen as calves transition from consuming a liquid diet to a completely solid diet. These changes can influence growth and calf health, being greatly affected by preweaning diet as well as the transitional steps used to wean calves. A 2 × 2 factorial design of moderate [MOD; 0.66 kg of dry matter (DM)] or high (HI; up to 1.1 kg of DM) feeding rates of milk replacer (MR) and abrupt (AB; 7-d step-down) or gradual weaning (GR; 21-d step-down) was used to study how preweaning program affects calf performance from 2 to 4 mo of age. Calves (n = 50) were randomly assigned to 1 of the 4 preweaning treatments. For the following 56-d grower portion of the experiment, calves were grouped into 12 pens based on MR program, with 4 to 5 calves per pen. Data were analyzed as a completely randomized design, with repeated measures when applicable, by PROC MIXED in SAS (version 9.4; SAS Institute Inc., Cary, NC). All calves received ad libitum access to water and a textured starter [42% starch and 20% crude protein (CP)] blended with 5% chopped grass hay. Overall, apparent digestibility coefficients (dC) of DM, neutral detergent fiber, and acid detergent fiber were greater for MOD compared with HI, and apparent dC of DM and ADF were greater for GR than for AB. No significant differences were detected between organic matter, CP, fat, starch, or sugar dC based on treatment, and no interactions were observed. However, by d 56 only starch dC differed by treatment. Weaning body weight (BW), hip width (HW), and hip height (HH) were greater for HI compared with MOD calves. Weaning HH was greater for AB than for GR calves. However, final BW, HW, HH, and body condition score, as well as average daily gain, did not differ among treatments. An interaction occurred where feed efficiency (gain/feed) was reduced with GR weaning in MOD, whereas the opposite occurred in the HI group. When feeding calves a moderate level of MR, a several-step gradual weaning is not necessary to ensure growth and development; however, calves should be gradually weaned when offered a high level of MR.

Predicting Productive Performance in Grow-Finisher Pigs Using Birth and Weaning Body Weight.

Simple SummarySmaller than average sized pigs requiring extra time to reach target slaughter weight are often referred to as slow growing pigs. This subset of pigs poses a management challenge and may have economic implications for pig producers. The aims of this study were to investigate the effect of birth and weaning body weight on performance of grow-finisher pigs and to estimate cut-off values for birth and weaning body weight in order to identify slow growing pigs early in life. Pigs with low birth and weaning weight grew slower compared to pigs with higher birth or weaning weight, although feed conversion efficiency was similar for both groups. Pigs weaned at approximately 28 days weighing less than 3.7 kg would be identified as slow growing pigs within a batch. Moreover, a cut-off value of 1.1 kg of body weight at birth and 6.4 kg of body weight at weaning would allow pig producers to identify the pigs that are likely to reach target slaughter weight at 22 weeks of age. In conclusion, birth body weight does not always determine subsequent growth performance, and the cut-off values identified could be used on farm to design new management and nutritional strategies for slow growing pigs.This study aimed to (1) investigate the effect of birth and weaning body weight (BW) on performance indicators of grow-finisher pigs and (2) estimate birth and weaning BW cut-off values in order to identify slow growing pigs (SGP). Pigs (n = 144) were classified as SMALL (0.9 ± 0.13 kg) or BIG (1.4 ± 0.20 kg) at birth and re-classified as SMALL (5.4 ± 1.6 kg) or BIG (6.3 ± 1.91 kg) at weaning. Individual BW was recorded bi-weekly, and feed intake was recorded on a daily basis. Average daily gain (ADG) and feed intake, feed conversion ratio (FCR) and days to target slaughter weight (TSW) were calculated. SMALL–SMALL pigs had lower ADG (p < 0.05) requiring 167.1 days (i.e., 14.2 extra days) to TSW (p < 0.05) compared with BIG pigs at birth and/or weaning. However, FCR was similar between groups (p > 0.05). Pigs weaned at <3.7 kg BW would likely be SGP. Pigs born at ≥1.1 kg BW or weaned at ≥6.4 kg BW are more likely to reach TSW at 22 weeks of age. The results suggest that birth BW might not be the best predictor for subsequent performance, as some small-born pigs were able to catch up with their bigger counterparts. The cut-off values identified could be used to design specific management and nutritional strategies for SGP.

Effects of dietary levan-type fructan on growth performance, blood profiles, fecal noxious gas emissions, and litter performance in lactating sows

In total, 28 multiparous sows (n = 7) and their litters were used to determine the effects of levan-type fructan supplementation on growth performance, nutrient digestibility, blood profiles, and fecal noxious gas emissions. The dietary treatments included (1) CON, basal diet; (2) FC1, CON + 0.1% fructan; (3) FC2, CON + 0.2% fructan; and (4) FC3, CON + 0.3% fructan. No significant differences were observed (P &gt; 0.05) in body weight (BW), average daily feed intake, or back fat loss in lactating sows among treatments. However, blood lymphocyte concentrates were higher (P &lt; 0.05) in sows fed levan-containing diets than in those fed the CON diet. Weaning BW and overall average daily gain (ADG) of piglets in the FC3 treatment were higher (P &lt; 0.05) than piglets in the CON treatment. Blood lymphocytes and nutrient digestibility of sows, as well as the weaning BW and the ADG of piglets were increased linearly (P &lt; 0.05) as the concentration of levan increased in the diet. The diarrhea score of piglets and the fecal gas emissions of sows decreased linearly (P &lt; 0.05) as dietary levan increased. In conclusion, levan supplementation did not affect feed intake or decrease back fat loss of lactating sows, but it improved nutrient digestibility and immune ability, decreased fecal noxious gas emissions of lactating sows, and it improved growth performance and reduced diarrhea in piglets.

Nose Color of Charolais × British Crossbred Beef Steers Alters Body Weight at a Common Degree of Fatness and Marbling Score in Steers Reared Under Similar Management from Birth through Finishing

This study evaluated differences in nose color (Black or Pink) on carcass traits and mature body weight in Charolais × British crossbred beef steers. Steers (n = 180; 280±18.2 kg) were weaned and fed for 244 days until harvest. The hypothesis was that steers with black noses had Black Angus dams and that steers with pink noses had Red Angus dams and that these genotypic differences might influence carcass traits and body weight a common fatness endpoint. Data were analyzed as a randomized complete block design using the GLIMMIX Procedure of SAS 9.4 (SAS Inst., Inc., Cary, NC) with the main effect of nose color and finishing phase pen included as a random effect. Individual steer served as the experimental unit for all analyses. Weaning Body Weight (BW) differed (P = 0.05) between black and pink. Final shrunk BW, hot carcass weight, dressing percentage, longissimus muscle area and mRatio did not differ (P ≥ 0.16) between black nose or pink. Rib fat depth was greater (P = 0.01) for black compared to pink. Measures for kidney-pelvic-heart fat tended to increase (P = 0.07) in black nosed steers. Marbling score was greater (P = 0.01) in black versus pink nosed steers. Steers with black noses had greater (P = 0.01) numerical yield grade and lower (P = 0.01) retail yield. Black nosed steers had greater (P = 0.01) estimated Empty Body Fat (EBF) and tended (P = 0.07) to have decreased BW at 28% EBF. The distribution of USDA Quality Grades tended (P = 0.10) to differ between nose classification. Total live weight gain was compromised in the black nosed steers if the steers would have been harvested at an equal fatness endpoint

Endoparasites in Sows and Selected Reproduction Parameters

Abstract The aim of the study was to analyze infection of sows with endoparasites depending on their physiological phase and length of exploitation, as well as to determine the effects of infection on selected parameters of reproductive performance. 300 fecal samples collected from the same 75 sows in 4 phases of the production cycle (dry sows, low pregnancy, high pregnancy, lactation) were tested in the experiment. Species and gender diversity, prevalence, OPG and EPG were determined in the study. These parameters were compared in terms of the physiological phase and the length of exploitation. Selected parameters of reproductive performance of sows were also examined, which were compared taking into account the length of exploitation and sows infection with individual parasites. The study showed that the entire population was infected with two parasites at all physiological phases: Eimeria spp. (17% prevalence, 2275 OPG) and Ascaris suum (5% prevalence, EPG 79). The presence of parasites from Eimeria genus (prevalence 40%, OPG 2976) in sows exploited for 1 year had a negative effect on some parameters of their reproduction performance. Infected sows, compared to noninfected ones, were characterized by a lower number of live piglets (by 0.21 heads) (p≤0.05), a higher number of stillborn piglets (by 0.21 heads) (p≤0.05), as well as lower daily weight gains of piglets (by 15 g) (p≤0.05), which contributed to their lower weaning body weight (by 0.45 kg) (p≤0.05).

Combined yeast culture and organic selenium supplementation during late gestation and lactation improve preweaning piglet performance by enhancing the antioxidant capacity and milk content in nutrient-restricted sows.

This study was conducted to investigate the effects of dietary supplementation with yeast culture (YC) and organic selenium (Se) during late gestation and lactation on reproductive performance, milk quality, piglet preweaning performance, antioxidant capacity, and secretion of immunoglobulin in multiparous sows. A total of 160 healthy cross-bred sows (Landrace × Yorkshire, mean parity 4.1 ± 0.3) were randomly assigned to 4 groups as follows: 1) high nutrient (HN), 3,420 kcal/kg digestible energy (DE) and 18.0% crude protein (CP); 2) low nutrient (LN), 3,240 kcal/kg DE and 16.0% CP; 3) LN + YC, LN diet + 10 g/kg YC; 4) LN + YC + Se, LN diet + 10 g/kg YC + organic Se (1 mg/kg Se). Feeding trials of sows started from d 85 of pregnancy to d 35 of lactation. Compared with sows in the LN group, sows fed the LN + YC + Se diet had greater litter weaning weight, average litter gain, and milk fat content (14-d and 25-d milk) (P < 0.05). The content of malonaldehyde (MDA) (colostrum and 14-d milk) was lesser, and the activity of glutathione peroxidase (GSH-Px) (colostrum and 25-d milk) was greater when sows were fed the LN + YC + Se diet, compared with sows fed the LN diet (P < 0.05). Supplementation of YC and organic Se in the nutrient-restricted diet improved sows’ reproductive performance and pig weaning body weight by enhancing the antioxidant capacity and fat content in milk.

Interrelation between body weights of sire, dam and their lambs at early stage of growth

Records of female lambs and their parents of the Mis sheep breed have used. All animals are approximately have weaned at 90 days of age. Descriptive statistics, paired sample test, paired differences, measures of association, correlations and regression of body weights between female lambs and their parents have done. A complementary least body weights at 30 days and weaning between dams and lambs but utmost weight at 30 days, the lambs were higher while at weaning, the dams had higher weight. It can observe that the averages on body weights the rams were the highest, followed by lambs and the lowest the dams? body weights. The coefficient of determination of R2 varies from low to high, indicating that the lamb's body weight has more influenced by other factors that we have not considered. There were significant correlations between lamb body weight at birth and sire/dam body weight at birth. The results showed highly significant correlations of lamb's body weight at 30 days with dams but with sires, positive and very low. There had positive but no significant correlation between lamb body weight at weaning and sire body weight at weaning. Lamb body weight at weaning and dam body weight at weaning are highly correlated.

394 Exploring the relationships between cow-calf management systems as affected by protein/methionine nutrition during gestation on the performance of cow-calf pairs prior to weaning

Abstract A three-way factorial arrangement was used to assess impacts of protein/methionine nutrition during gestation and two lactational management systems on performance of cow-calf pairs pre-weaning. 140 crossbred beef cows were managed in drylot and randomly assigned to one of six nutritional treatments during the third trimester of gestation. Cows were fed to meet 110% (HP), 100% (MP), or 90% (LP) of metabolizable protein requirements for late-gestation (NRC, 2016), with(without) rumen-protected methionine (RPM) for 8 weeks prior to parturition. Post-partum, cow-calf pairs were managed in drylot (DL) and fed ad libitum, a ration formulated to meet lactational nutrient requirements, or rotationally grazed on pasture (PAS). Cow body weights (BW) and body condition scores (BCS) and calf BW were recorded at regular intervals. All data were analyzed using PROC GLIMMIX (SAS v9.4). HP cows were heaviest at calving (P = 0.02), but calf birthweight was unaffected by gestational nutrition (P &amp;gt; 0.19). Gestational nutrition did not impact cow conception rate (CR), or calf BW and ADG (P &amp;gt; 0.17). Lactational management system (PAS, DL) did not affect cow BCS or CR (P &amp;gt; 0.13), but impacted cow and calf BW and ADG. PAS calves were heavier, had greater ADG, and heavier weaning BW than DL calves (P &amp;lt; 0.02). This came at the expense of BW loss throughout lactation and lower ADG for PAS cows, versus BW gains and greater ADG for DL cows (P &amp;lt; 0.0001). An interaction between protein level and RPM supplementation was present for cow BW at calving and weaning, and BW change throughout lactation (P &amp;lt; 0.04), with tendencies for interactions for cow ADG and BCS (P &amp;lt; 0.09). Overall, prepartum protein/methionine supplementation did not affect calf performance prior to weaning, but may have affected cow performance during lactation. Rotationally grazing cow-calf pairs on pasture improved pre-weaning calf gains, but reduced cow gains throughout lactation.

OxidativeStress and DNA methylation in male rat pups provoked by the transplacental and translactational exposure to bisphenol A.

The epigenetic changes induced by environmental contaminants play important roles in the inheritance of male reproductive dysfunction. The present study investigated DNA methylation changes and some oxidative stress biomarkers induced by bisphenol A (BPA) in male offspring. A total number of 48 female albino rats were administered orally with 50 μg/kg of BPA/day during gestation and/or lactation periods. At postnatal day 60, the samples were collected from the male pups to assess the serum testosterone, malondialdehyde (MDA) level, superoxide dismutase (SOD), glutathione S-transferase, and glutathione peroxidase (GSH-Px) activities in testicular tissue. DNA methylation in both DNA (cytosine-5)-methyltransferase 3A and estrogen receptor alpha genes was detected by methylation-specific PCR. BPA exposure resulted in significant decrease in the anogenital distance, testis and epididymis weights, serum testosterone level, SOD, GST, and GSH-Px levels with significant increase in weaning body weight and the MDA level. Additionally, BPA caused marked hypermethylation within Dnmt3A and ER- ∝ genes promoter regions in the testis of rat male pups. Graphical abstract.

Impacts of postweaning growth rate of replacement beef heifers on their reproductive development and productivity as primiparous cows1.

This experiment evaluated the effects of postweaning body weight (BW) gain of replacement beef heifers on their reproductive development and productivity as primiparous cows. Seventy-two Angus × Hereford heifers were ranked on day -6 of experiment (17 d after weaning) by age and BW (218 ± 1.6 d of age and 234 ± 3 kg of BW), and assigned to receive 1 of 3 supplementation programs from days 0 to 182: 1) no supplementation to maintain limited BW gain (LGAIN), 2) supplementation to promote moderate BW gain (MGAIN), or 3) supplementation to promote elevated BW gain (HGAIN). Heifers were maintained in 2 pastures (36 heifers/pasture, 12 heifers/treatment in each pasture) with free-choice alfalfa-grass hay, and supplements were offered individually 6 d per week. Heifer shrunk BW was recorded on days -6 and 183 for average daily gain (ADG) calculation. Blood samples were collected for puberty evaluation via plasma progesterone weekly from days 0 to 182. On day 183, heifers were combined into a single group and received the same nutritional management until the end of the experimental period (day 718). From days 183 to 253, heifers were assigned to a fixed-time artificial insemination program combined with natural service. Average daily gain from days 0 to 182 was greater (P < 0.01) in HGAIN vs. MGAIN and LGAIN (0.78, 0.60, and 0.37 kg/d, respectively; SEM = 0.02), and greater (P < 0.01) in MGAIN vs. LGAIN heifers. Puberty attainment by the beginning of the breeding season was also greater in HGAIN vs. MGAIN and LGAIN (87.5%, 62.5%, and 56.5%, respectively; SEM = 7.1) but similar (P = 0.68) between MGAIN vs. LGAIN heifers. A treatment × day interaction was detected (P < 0.01) for calving rate, as HGAIN heifers calved earlier compared with MGAIN and LGAIN heifers. Ten heifers per treatment were assessed for milk production via weigh-suckle-weigh at 56.8 ± 1.5 d postpartum, followed by milk sample collection 24 h later. No treatment differences were detected (P ≥ 0.16) for milk yield and composition. However, mRNA expression of GLUT1 in milk fat globules was less (P ≤ 0.02) in LGAIN vs. MGAIN and HGAIN heifers, and expression of GLUT8 mRNA was also less (P = 0.04) in LGAIN vs. HGAIN heifers. No treatment differences were detected (P ≥ 0.44) for offspring weaning BW. Collectively, results from this experiment indicate that HGAIN hastened the reproductive development of replacement heifers, without negatively affecting their milk productivity and offspring weaning weight as primiparous cows.

Effects of the Ratio of Insoluble Fiber to Soluble Fiber in Gestation Diets on Sow Performance and Offspring Intestinal Development

Simple SummaryGestating sows fed a diet rich in dietary fiber show improved performance. Dietary fiber is composed of insoluble fiber and soluble fiber. The ratio of insoluble to soluble fiber may affect overall diet utilization and influence sow performance. Maternal nutrition significantly affects offspring intestinal development; therefore, we investigated the effects of the ratio of insoluble to soluble fiber in gestation diets on sow performance and offspring intestinal development. Our results suggested that, when the dietary fiber levels were the same in gestation diets, the ratio of insoluble to soluble fiber affected the development of intestinal morphology and enzymatic activity related to nutrient digestion and absorption, and consequently affected the average daily gain during lactation and average piglet body weight at weaning. When the ratio of insoluble to soluble fiber was 3.89 in the gestation diet, higher average piglet body weight and litter weight at weaning were observed. These results may provide guidance for the application of fiber in pig production.To investigate the effects of the ratio of insoluble fiber to soluble fiber (ISF:SF) on sow performance and piglet intestinal development, we randomly assigned 64 gilts to four treatments comprising diets with the same level of dietary fiber, but different ISF:SF values of 3.89 (T1), 5.59 (T2), 9.12 (T3), and 12.81 (T4). At birth and weaning, six piglets per treatment at each phase were slaughtered for sampling. As ISF:SF increased, the mean piglet body weight (BW) at weaning and piglet BW gain, which were all significantly higher in T1 and T2 compared with T3 and T4 (p < 0.05), showed a linear decrease (p < 0.05); the crypt depth of the jejunum in weaned piglets linearly increased, whereas the duodenal weight, jejunal villus height, and villus height/crypt depth in newborn piglets and enzymatic activity of lactase, sucrase, and maltase linearly decreased (p < 0.05). No differences were observed in the yield and composition of milk (p > 0.05). Moreover, when the ISF:SF was 3.89 in gestation diets, higher piglet BW at weaning occurred, possibly because the ISF:SF affected development and enzymatic activity in the small intestine—effects related to digestion and absorption of nutrients—and consequently enhanced piglet BW gain.

Influence of weaning date and late gestation supplementation on beef system productivity I: animal performance.

A 4-yr experiment examined how weaning date and prepartum nutrition affected productivity in a spring (March and April) calving system. Crossbred beef cows (479 ± 59 kg, n = 144) were used in a completely randomized design with a 2 × 4 factorial treatment arrangement: 1) cows were weaned in early October or early December; and 2) during late gestation cows were fed on a dry matter basis a 32% crude protein supplement at 0, 0.41, or 0.82 kg/cow/d on dormant upland range or grazed corn residue without supplement. Cow body condition score (BCS) was affected (P ≤ 0.01) by treatment prior to parturition and breeding but was similar (P > 0.27) among all treatments in October. Dams on a higher nutritional plane during winter treatment had greater (P < 0.01) BCS and body weight (BW) prior to parturition and breeding. Subsequent pregnancy rates (88% to 97%) were not influenced (P > 0.76) by weaning date, but tended (P = 0.10) to be lower for cows grazing winter range without supplement. Calves born to dams grazing winter range without supplement had lower (P < 0.01) BW in October and adjusted weaning BW. Pre-breeding BW of heifers weaned in December born to cows grazing winter range without supplement was lower (P < 0.01) than contemporaries born to cows in all other treatment combinations. However, postweaning (0.48 kg/d) and postbreeding (0.42 kg/d) average daily gain, percentage cycling before breeding (33%), and pregnancy rate (81%) was similar (P > 0.12). Within weaning date, steers born to cows grazing winter range without supplement had lower (P < 0.05) hot carcass weight (HCW) than contemporaries born to cows grazing corn residue. Cows weaned in December had decreased BW and BCS but similar pregnancy rates as cows weaned in October. Weaning date and dam maternal nutrition had minimal impact on heifer progeny pregnancy rate. Steer progeny born to dams on a higher nutritional plane had similar HCW at slaughter when adjusted to equal fat thickness.

Effects of extended-release eprinomectin on fescue toxicosis, performance, and reproduction on fall-calving beef cows.

The objective of this experiment was to evaluate effects of extended-release eprinomectin on fescue toxicosis and impacts on performance and reproduction in fall-calving beef cows. Fall-calving Angus × Simmental multiparous cows [n = 335; age = 5.8 ± 2.1 yr; 586.5 ± 6.0 kg body weight (BW); 5.48 ± 0.05 body condition score (BCS)] were stratified by BW, age, and BCS and randomly assigned to one of three treatments. Treatments included a spring injection of extended-release eprinomectin (SERE) on day 0, a fall injection of extended-release eprinomectin injection (FERE) on day 84, and a saline control (CON). All treatments were administered at a rate of 1 mL/50 kg BW. Prior to the experiment, all cows were treated with oral fenbendazole to minimize parasite load. Cows grazed endophyte-infected tall fescue. Hair coat score (HCS), BW, and BCS were recorded on all cattle. Fecal egg count (FEC), respiration rate (RR), horn fly and tick count, hematocrit (% packed cell volume, PCV), and serum prolactin were analyzed on a subset of cows (35/treatment). On day 194, cows were artificially inseminated (AI) and 11 d following AI were exposed to bulls for 51 d. Milk production was estimated on day 210 on a subset of 85 cow–calf pairs (28–29/treatment). There was a tendency for a treatment × time interaction (P = 0.07) for FEC likely driven by an increase in FEC of the CON cattle at day 126 compared to SERE and FERE. There was a tendency for a treatment × time interaction (P = 0.06) for cow BW, largely driven by time differences; however, there was no effect of treatment (P = 0.84) on BW. There was no difference (P ≥ 0.13) in cow PCV, fly and tick count, BCS, HCS, RR, and serum prolactin throughout the experiment. Additionally, there was no difference (P ≥ 0.46) in Julian calving date, calf birth BW, or milk production between treatments. Interestingly, heifer calves born to FERE dams tended to have greater (P = 0.06) weaning BW compared to heifer calves born to CON dams. In addition, there was no difference (P ≥ 0.17) in heat patch scores, AI conception rates, or overall pregnancy rates between treatments. Extended-release eprinomectin did not impact cow growth performance, reproductive performance or fescue toxicity symptoms when grazing endophyte-infected tall fescue; however, calf weaning BW tended to be improved.

Effect of optimizing dietary valine-to-lysine ratio in late gestation or lactation on biochemical indices and performance of lactating primiparous sows

A study was conducted to investigate the effect of optimizing valine-to-lysine ratio by dietary supplement with valine (Val) in late gestation (starting on day 85) or lactation on biochemical indices and lactation performance. Sixty pregnant gilts (Yorkshire × Landrace) were randomly allocated to one of four treatments in a 2 × 2 factorial experimental design, where the factors were supplementation with L-Val (optimizing total valine: lysine to 0.87:1) or with L-alanine (Ala, isonitrogenous control) in late gestation and/or lactation. The diets contained 14.02 MJ of ME/kg energy and 203.1 g/kg to 203.3 g/kg crude protein (CP), were fed at 2 kg daily during late gestation and ad libitum during lactation. Feeding the Val-supplemented diet compared with control during late gestation improved the weaning body weight (BW) and of sucking piglets (P < 0.05), and a marked increase in maternal feed intake (P < 0.05); there were no differences in backfat loss, weaning-to-estrus interval (WEI) or biochemical variables. With Val-supplementation of the lactation diet, weaning BW of sucking piglets and BW gain of litters were greater than the controls (P < 0.05). Improvement of milk fat (day 7 to day 14 of lactation), milk protein (day 7 of lactation) and non-fat solids (day 7 to day 14 of lactation) were noted from the sows fed Val-supplemented diet during lactation (P < 0.05). On day 14 of lactation, plasma concentrations of free Val and prolactin in sows and concentrations of some free amino acids (AA) in milk were greater (P < 0.05), and plasma glucose was lower (P < 0.05), in response to Val supplementation during lactation. There was no gestation × lactation Val interaction on the performance of sows and their suckling piglets. Collectively, results indicate the beneficial effects of optimizing the total dietary Val: Lys to 0.87:1 in late gestation and lactation on improving the performance of lactating sows.

Effect of lactation length caused by the management production system on piglet performance until slaughter

Since weaning in commercial conditions is usually done on a fixed day for all sows belonging to the same parturition batch, litters have differences in days of lactation, depending on the farrowing date. Days of lactation affect the piglet's weaning body weight (BW), and it is hypothesized that it may also affect the slaughtering BW. The objective of this study is to observe the effect of the lactation length of sows belonging to the same batch on the subsequent performance of piglets at weaning and at 165 days of age. A total of 796 male and female crossbreed piglets [Pietrain x (Landrace x Large White)] from 92 sows (parities ranging from 1 to 7) were used and individually weighed from birth to slaughter. Weight data for each pig were adjusted using the double exponential Gompertz model (BW = A*exp(-exp(b-(c*t)))), and the BW at day 165 of age was estimated for each pig using this model to correct for the age effect among pigs. Means were calculated as LSmeans. Birth body weight (BBW) was added as a covariate and lactation length as a factor using the Proc GLM of SAS. The effect of days of lactation was found to be significant at weaning (P < 0.001) and at the end of the cycle (P < 0.001). Results (kg of BW) for weaning were 4.7a, 5.3b, 5.6c, 6.0c, and 7.2d kg, and for 165 d of age they were 92.3a, 96.4b, 98.0bc, 102.9d, and 101.7cd kg for 18, 19–20, 21–22, 23–24, and > 25 days of lactation, respectively. The consequence was that a difference of 2.4 kg at weaning increased to 9.4 kg at day 165. Increasing the length of lactation from 18 days to more than 25 days caused a significant linear BW increase at weaning (P < 0.001) and a quadratic response at 165 days of life (P < 0.001). It is concluded that piglets coming from sows that farrow earlier in a batch increase the days of lactation and produce heavier pigs at 165 days of age; consequently, shortening the farrowing period within a batch, without necessarily using artificial farrow synchronization, could help to reduce the differences in BW at the end of the cycle, and may help producers to increase farm efficiency.

MILK PRODUCTION AND BODY WEIGHT AT WEANING AND THEIR RELATIONSHIPS WITH BODY AND UDDER MEASUREMENTS IN MERIZ GOATS

To investigate the correlation coefficients among the anatomical body structure and udder characteristics with each of body weight and milk production, 54 lactating Meriz does were randomly selected, kidded within 2 weeks in March, 2018. At weaning body weight as well as 6 body measurements and 8 udder and teat measurements were recorded. Also, Milk yield was recorded at weekly intervals till the does are dried-off. Results revealed moderate positive correlations between body measurements and milk production, while highest correlations were observed between udder measurements and milk production. Also, there was a strong positive correlation between body weight and body measurements. Four components were found meaningful; the first component was labeled as the ‘teat dimensions’ factor, ‘udder dimensions’ factor is a second component and the combination of the third and fourth component was interpreted as the ‘body dimensions’ factor. Therefore, the best predictors for body weight was rump height, heart girth and body length. Also, udder length, udder width, distance between teats and teat dimension were best predictors for milk production.

Influence of repeated trace mineral injections during gestation on beef heifer and subsequent calf performance.

Commercial Angus heifers (n = 190; body weight (BW) = 315 ± 49.3 kg) were used to determine the effects of trace mineral injections during gestation on heifer and subsequent calf performance. Heifers received three previous subcutaneous trace mineral (Multimin 90 [MM]; n = 93) or sterilized physiological saline (CON; n = 97) injections approximately 90 d apart. These treatments were maintained and subsequent injections were given 205, 114, and 44 ± 26 d prepartum. Heifers were provided free-choice inorganic minerals. Heifer BW and body condition scores (BCS) were collected at trial initiation (296 ± 26 d prepartum) and 5- to 10-week intervals thereafter. Liver samples were collected at trial initiation, 5 and 176 ± 3 d postpartum from a subset of cows to determine trace mineral status. Milk production was assessed on 80 cow–calf pairs (40/treatment) at 71 ± 15 d postpartum. Cows were artificially inseminated (AI) 82 d postpartum and then exposed to bulls for 38 d. Data were reported from 174 calves (n = 87 calves/treatment). Calf liver samples were collected 5 and 147 ± 3 d postpartum to determine trace mineral status. Calf weaning BW was collected at 159 ± 26 d postpartum. Calf performance including calving date, birth BW, weaning BW, average daily gain (ADG), and health data were collected. Heifer BW and BCS did not differ (P ≥ 0.72) throughout the experiment. Multimin heifers tended (P = 0.08) to have greater initial liver Se and tended to have decreased (P = 0.08) initial liver Zn compared with CON. At calving, MM cows had increased (P ≤ 0.01) liver Cu and Se. There was no difference (P ≥ 0.47) in Julian calving date, calving percent, or unassisted births. Calf birth BW was lesser (P = 0.02) for MM than CON calves, and MM calves had greater (P = 0.03) liver Cu concentrations at birth than CON calves. Despite MM cows having increased (P < 0.01) milk production, calf weaning BW and ADG were not different (P ≥ 0.87). In addition, calf morbidity and mortality were not different (P ≥ 0.43) between treatments. Calf mineral status was not different (P ≥ 0.57) at the time of weaning regardless of treatment; however, MM cows had decreased (P = 0.03) liver Zn. Multimin cows had decreased (P = 0.05) AI pregnancy rates, yet there was no difference (P = 0.34) in overall pregnancy rate. Supplementing an injectable trace mineral during heifer development and gestation increased cow milk production and resulted in decreased AI pregnancy rates; however, there was no effect on overall pregnancy rates or preweaning calf health or performance.