The relationships between leptin gene polymorphism and some performance traits in Simmental and Brown Swiss cattle

This study was carried out to determine the genotype and allele frequencies and association between the Leptin gene Sau3AI polymorphism and some performance characteristics in Simmental (n=60) and Brown Swiss (n=62) breed cattle raised in the province of Erzurum, Turkey. In the study, leptin/Sau3AI gene polymorphisms in DNA isolated from blood samples obtained from Simmental and Brown Swiss cattle were determined using PCR-RFLP method. As genotype frequencies of leptin/Sau3AI gene in the population, in Brown Swiss cattle, 88,7% with genotype AA, 9,7% with AB and 1,6% with BB genotypes were determined, Simmental breed cattle, 78,3% with genotype AA, 16,7% with AB and with 5,0% BB genotypes were determined. AA genotype frequencies were the highest in the population, and those with BB genotypes had the lowest frequency in both breeds. When the population was examined in terms of allele frequencies, the A allele was 0,87 and B allele was 0,13 in the Simmental cattle, and the A allele was 0,94 and B allele was 0,06 in the Brown Swiss breed. According to Hardy-Weinberg genetic balance test, the distribution of genotype frequencies was balanced (P>0.05) in the Brown Swiss breed but not in the Simmental breed in the population studied. As a result of the analysis performed in the Simmental breed, the general averages were found to be 5422,4 ± 1901,74 kg for actual milk yield, 5626,6 ± 1475,85 kg for 305-day milk yield, 298,7 ± 84,80 days for lactation duration and 18,5 ± 4,84 kg for daily milk yield. According to the statistical analysis results, the effect of genotype on the actual milk yield during lactation, lactation duration and daily milk yield was significant. As a result of the analysis made in the Brown Swiss breed, the general averages were 3917,8 ± 1584,38 kg for actual milk yield, 4614,3 ± 982,62 kg for 305 days milk yield, 254.9 ± 99.88 days for lactation duration and 16,0 ± 3,82 kg for daily milk yield. According to the statistical analysis results, the effect of genotype on performance characteristics was insignificant in Simmental and Brown Swiss cattle.

Allo-suckling occurrence and its effect on lactation and nursing duration in harbour seals (Phoca vitulina) in Orkney, Scotland

Fostering and allo-suckling are widespread among pinnipeds, and several hypotheses have been formulated to explain their occurrence. Here, we describe the occurrence of allo-suckling in harbour seals from photo-identification data of females and pups in Orkney (Scotland) during the pupping seasons between 2016 and 2019. We used a generalised linear model framework to investigate the effect of allo-suckling on the duration of lactation (females) and of nursing period (pups). A generalised additive model framework was used to explore how the probability of allo-suckling varied throughout the pupping season, and with changes in mother-pup separation time. Allo-suckling was observed in 31 females, at higher rates (18–37% of lactating females and 18–47% of the pups every year) than those observed in other phocid populations, with 13 females allo-suckling in multiple years. The duration of the pups’ nursing period was not affected by allo-suckling occurrence. However, females in mother-pup pairs where both mother and pup allo-suckled had longer lactation duration than when only the pup allo-suckled, or than in pairs where no allo-suckling was observed. The probability of allo-suckling increased during the pupping season and with increased mother-pup separation time. However, the proximate causes and the consequences on future reproductive output and pup survival remain unknown.Significance statementAllo-suckling, where females nurse others’ young, is widespread in pinnipeds, particularly among true seals. Given the high costs of lactation in pinnipeds, allo-suckling is a puzzling behaviour. Using photo-identification and field observations, we examined the occurrence of allo-suckling in harbour seals at a colony in Orkney, Scotland. We found that allo-suckling is common among seals at the study site, and at rates higher than reported elsewhere. Our results show that allo-suckling does not appear to affect the duration of the pups’ nursing period but does increase the lactation duration of females who suckle other pups and whose own pups also allo-suckle. This study highlights an area which requires further investigation as the energetic costs and benefits of allo-suckling remain poorly understood.

The Association of Lactation Duration with Visceral and Pericardial Fat Volumes in Parous Women: the CARDIA Study

Background Lactation is associated with lower risks for cardiovascular disease in women. Organ-related adiposity, which plays significant roles in the development of cardiometabolic diseases, could help explain this observation. We evaluated the association of lactation duration with visceral (VAT) and pericardial (PAT) fat volumes in women. Methods Data were obtained from 910 women enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study (1985-86) without diabetes prior to pregnancy who had ≥1 birth during 25 years of follow-up and had VAT and PAT measured from computed tomographic scans in 2010-2011. Cumulative lactation duration across all births since baseline was calculated from self-reports collected at periodic exams. Results At baseline, the average age of women (48% black, 52% white) was 24 ± 3.7 years. After controlling for baseline age, race, smoking status, body mass index, fasting glucose, family history of diabetes, fat intake, total cholesterol, physical activity and follow-up covariates (parity, gestational diabetes), the mean fat volumes across categories of lactation (none (n=221), 1 to 5 months (n=306), 6 to 11 months (n=210), and ≥12 months (n=173)) were 122.0, 113.7 105.0, and 110.1 cm3 for VAT and 52.2, 46.7, 44.5 and 43.4 cm3 for PAT, respectively. Changes in body weight from the first post-baseline birth to the end of follow-up mediated 21% and 18% of the associations of lactation with VAT and PAT, respectively. Conclusions In this prospective study, longer cumulative lactation duration was associated with lower VAT and PAT volumes, with weight gain partially mediating these associations

Demographic, Social, and Personal Factors Associated with Lactation Cessation by 6 Weeks in Mothers of Very Low Birth Weight Infants

Background Although mother’s own milk decreases prematurity-associated morbidities, mothers of infants born preterm and very low birth weight experience a significantly shorter lactation duration. Little is known regarding factors associated with lactation cessation during the hospitalization of a very low birth weight infant. Research aim To determine demographic, social, and personal factors associated with lactation cessation by 6-weeks postpartum in mothers delivering very low birth weight infants. Methods We used a retrospective, longitudinal, two-group comparison design using data from a randomized control study. Mothers of very low birth weight infants ( N = 142) were enrolled from a labor and delivery unit associated with a Level 4 neonatal intensive care unit. Demographic, social, and health information was obtained from the medical records. Participants were surveyed regarding lactation goals, experience, and reason(s) for cessation. Results Participants who did not continue lactating for more than 6 weeks were more likely to be unemployed ( p = .019), Medicaid eligible ( p = .009), less educated ( p < .031), smoke ( p = .002), provide less skin-to-skin care ( p = .007), and to delay the decision to provide their milk to their infant ( p = .007). After Bonferroni adjustment, only minutes of skin-to-skin care remained statistically significant. Insufficient maternal milk production was the most common reason for lactation cessation. Conclusion While the etiology of lactation cessation is often non-modifiable, strategies aimed at maintaining mother’s own milk production, smoking cessation, increasing skin-to-skin care, and promoting an earlier decision to lactate, may prolong lactation duration in this vulnerable population. This RCT was registered (2012-00071) with ClinicalTrials.com on 6/28/2013.

Physical development, ease of integration into the dairy herd and performance of primiparous dairy cows reared with full whole-day, half-day or no mother-contact as calves

We investigated whether different rearing conditions affected the physical development, ease of integration into the dairy herd and performance of primiparous dairy cows and the results are reported in this Research Communication. The three rearing conditions investigated were whole-day cow-calf contact for 9 weeks (WDC), half-day contact for nine weeks (HDC) and no mother-contact (NC) with nipple-bucket-feeding (max. 2 × 3 l/d) and group-housing from the 8th day onward. After permanent separation from the dams (WDC and HDC), all calves had been nipple-bucket-fed and gradually weaned from week 10 to 13 of life and kept together as calves and heifers. Measures of physical development were trunk girth, height at withers and body weight. Lying behavior during the first 48 h after introduction to the dairy herd after first calving was used as an indicator of ease of integration. Performance measures were age at calving, lactation duration, milk yield and culling rates during the first lactation. No differences between WDC and HDC could be detected. Moreover, no treatment-effects on physical development or performance could be found. All treatments showed reduced lying for the first 24 h after introduction to the dairy herd. Afterward NC-heifers lay less than WDC, with HDC-heifers ranging in between. We conclude that under the conditions investigated higher weights two weeks after weaning in WDC- and HDC-calves did not carry through to the first lactation and did not lead to earlier maturity and higher performance, but that integration into the herd may be alleviated when calves have early experience of the herd and associated conditions.

Abstract P423: Lactation Duration is Associated With Favorable Cognitive Function in Women During Midlife: The 30-year Cardia Study

Introduction: Lactation has been associated with lower incidence of the metabolic syndrome, type 2 diabetes, hypertension, and early atherosclerosis in women across the childbearing years. The lower risk of cardiometabolic diseases related to higher lifetime lactation may also extend to levels of cognitive function during midlife. Hypothesis: We tested the hypothesis that lactation duration is associated with better cognitive function in women during midlife independent of antecedent risk factors, as well as obesity, diabetes, and hypertension. Methods: We included 904 women aged 18-30 years at baseline (1985-86) enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study without no diabetes before ≥1 birth(s) after baseline, reported lactation duration for each post-baseline birth, and had 6 measures of cognitive function assessed at Year 30 (2015-16) including the Rey Auditory Verbal Learning Test (RAVLT), Digit Symbol Substitution Test (DSST), Stroop Test, Montreal Cognitive Assessment (MoCA), Letter Fluency Test, and Category Fluency Test. Linear regression models estimated mean (95%CI) cognition scores by lactation duration (none, >0 to 6 mos, > 6 to <12 mos, ≥12 mos) adjusted for race, age, BMI, blood pressure, parity, and follow up covariates (Table 1). Results: Among parous women (46% black, 54% white) at 30-year follow up, average age was 54 yrs and 47% had obesity, 61% delivered ≥2 births since baseline, 29% used anti-hypertensive medications and 16% developed overt diabetes. Black women were less likely to report >6 mos of total lactation for all births than white women (23% vs. 58%). Unadjusted and fully adjusted mean scores for 3 cognitive function measures had graded direct associations with increasing lactation duration; specifically, the RAVLT, MoCA and Category Fluency Test scores (all p-trend < 0.01). Conclusions: In this prospective study, longer lactation duration was associated with more favorable cognition scores among women during midlife.

Abstract MP57: Lactation Duration is Associated With Lower Visceral and Pericardial Fat Volumes in Parous Women: 25-year Follow-up in the Cardia Study

Introduction: Lactation has been associated with a lower risk of incident type 2 diabetes mellitus and cardiovascular disease (CVD) in women. However, the underlying mechanisms for these associations are not well understood. The longitudinal association between lactation and maternal fat volume has rarely been investigated. Hypothesis: We tested the hypothesis that lactation duration is inversely associated with maternal visceral and pericardial fat volumes. Methods: Data were obtained from 910 women enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study (1985-86) without diabetes prior to pregnancy who had ≥1 birth during 25 years of follow-up. Cumulative lactation duration across all births since baseline was calculated from self-reports collected at each exam. Volumes of visceral and pericardial adipose tissue were measured from computed tomographic scans at the Year 25 exam in 2010-2011. Methods: At baseline, the average age of women (48% black, 52% white) was 24 years (range: 18-30 years). During 25 years of follow-up, 76% of women reported lactation duration of ≥ 1 month. In adjusted linear regression models, lactation duration was inversely associated with visceral fat (p=0.021) and pericardial fat (p=0.001) volumes (Table). There was a significant interaction between race and lactation on visceral (p=0.035) and pericardial fat (p=0.027) volumes (Table). Formal mediation analysis showed a significant indirect effect of lactation duration on visceral (p=0.001) and pericardial fat (p=0.002) volumes through body weight change between the first postbaseline birth and the end of follow-up. Changes in body weight mediated 29.4% and 26.0% of the association between lactation duration and visceral and pericardial fat volumes. Conclusions: In this prospective study, the associations of longer lactation duration with lower visceral and pericardial fat volumes were partially mediated by body weight changes.

PSII-11 Comparison of multiple heat sources in the farrowing house: Effect on production and energy efficiency

Pre-weaning mortality, currently 20% in the United States, continues to rise and has been estimated to cost $400 to $600 million annually. Creep heat accounts for 36% (125 watt heat lamps) of the estimated 685,000 kWh electrical subtotal used in a 3000 sow farm. The objective of this study was to determine the effect of heat source type on production and electrical usage in the farrowing house at the Iowa State University Allen E. Christian Swine Teaching Farm. Seven multiparous crossbred sows housed in farrowing stalls were randomly assigned to a heat source treatment; Baby Pig Heat Mat – Single 48 (Kane Manufacturing, Pleasant Hill, IA; MAT n = 4) or Hog Slat® Poly Heat Lamp Fixture (Hogslat, Newton Grove, NC; LAMP n = 3). LAMP was controlled via a thermostat and varied by height and MAT was controlled via Thermostat Programmable 1 Zone (Kane Manufacturing, Pleasant Hill, IA). Both heat sources were set at 32.2⁰C and this was confirmed using an infrared temperature gun. Kill-A-Watt EZ Meter P4460 were connected to the individual heat source for group lactation duration to measure kilowatt hours (kWh) and were read twice weekly. Piglets were weighed on D1 (farrowing = D0) and at weaning. Production data including pre-weaning mortality and piglet weight at weaning were analyzed using a mixed model with parity, room and covariate of litter birth weight being fixed effects and sow being random. There was no difference in production values, pre-weaning mortality (P > 0.63,MAT=11.11%, LAMP = 11.76%) and piglet weaning weight (P > 0.13, MAT = 5.30 ± 0.18 kg, LAMP = 5.99 ± 0.21 kg), due to heat source type. The MAT (LS Mean 11.59 ± 1.31 kWh) used 4.2 times less electricity than LAMP (LS Mean 57.30 ± 1.56 kWh) (P < 0.05). In conclusion, with no difference in production values heat mats controlled with a programmable thermostat can decrease the high energy needs in the farrowing house.