Bovine sperm defects are affected by breed, age, season and region

This study reports the distribution of sperm morphology defects by breed, age, season and region of 11,387 bulls in 500 herds in Australia and near Pacific Islands during annual BBSE. Bull location was divided into 4 broad climatic regions based upon temperature, vegetation and climatic risk. Taking into account the impact of age, season, region, and breed there were differences between breeds in both percent morphologically normal sperm and in some individual categories of sperm abnormality (P < 0.001). Independent of breed, season and region, proximal droplets were significantly increased in bulls less than 20 months of age. This is the first study to comprehensively collect data from this wide geographical area and compare sperm morphology profiles among the Bos indicus and Bos taurus breeds. The findings of this study will act as a guide for veterinary practitioners and cattle breeders in the proportion of bulls that can be expected to pass the PNS test, by breed, age and region, based on a robust data set

The influence of peri-conception and first trimester dietary restriction of protein in cattle on meat quality traits of entire male progeny

Primiparous Santa Gertrudis heifers were used to evaluate the effects of gestational dietary protein content on meat quality traits of 20 month old bull progeny (n = 40). At − 60 d before AI, heifers were randomly allocated to HIGH or LOW protein diet (HPERI and LPERI). From 24 dpc, half of each treatment group changed to an alternative post-conception HIGH or LOW protein diet (HPOST and LPOST). LPERI and LPOST diets resulted in higher shear force of the semitendinosus muscle than HPERI (P = 0.053) and HPOST (P = 0.003), respectively. Heat-soluble collagen in the semitendinosus muscle was lower (P = 0.019) for LPERI than HPERI. Collagen and tenderness of the longissimus muscle were not affected by dam nutrition (P > 0.05). Color, pH, sarcomere length, cooking loss, compression values, desmin and troponin-T degradation, fiber type, intramuscular fat and polyunsaturated fatty acid content were not affected by dam nutrition during the peri-conception and first trimester gestational period (P > 0.05)

Correction: Gestational Dietary Protein Is Associated with Sex Specific Decrease in Blood Flow, Fetal Heart Growth and Post-Natal Blood Pressure of Progeny.

[This corrects the article DOI: 10.1371/journal.pone.0125694.]

Gestational dietary protein is associated with sex specific decrease in blood flow, fetal heart growth and post-natal blood pressure of progeny.

The incidence of adverse pregnancy outcomes is higher in pregnancies where the fetus is male. Sex specific differences in feto-placental perfusion indices identified by Doppler assessment have recently been associated with placental insufficiency and fetal growth restriction. This study aims to investigate sex specific differences in placental perfusion and to correlate these changes with fetal growth. It represents the largest comprehensive study under field conditions of uterine hemodynamics in a monotocous species, with a similar long gestation period to the human. Primiparous 14 mo heifers in Australia (n=360) and UK (n=180) were either individually or group fed, respectively, diets with differing protein content (18, 14, 10 or 7% crude protein (CP)) from 60 d prior to 98 days post conception (dpc). Fetuses and placentae were excised at 98 dpc (n = 48). Fetal development an median uterine artery blood flow were assessed monthly from 36 dpc until term using B-mode and Doppler ultrasonography. MUA blood flow to the male feto-placental unit increased in early pregnancy associated with increased fetal growth. Protein restriction before and shortly after conception (-60 d up to 23 dpc) increased MUA diameter and indices of velocity during late pregnancy, reduced fetal heart weight in the female fetus and increased heart rate at birth, but decreased systolic blood pressure at six months of age.Sex specific differences both in feto-placental Doppler perfusion indices and response of these indices to dietary perturbations were observed. Further, maternal diet affected development of fetal cardiovascular system associated with altered fetal haemodynamics in utero, with such effects having a sex bias. The results from this study provide further insight into the gender specific circulatory differences present in the fetal period and developing cardiovascular system

Cow maternal efficiency: “Giving the girls some credit”

The CRC for Beef Genetic Technologies (the 'Beef CRC') has established the Maternal Efficiency Project to provide new knowledge to help better inform beef producers on the impacts estimated breeding values for carcase fatness/carcase muscularity and for feed efficiency have on maternal efficiency, especially under variable nutritional environments. The project is being conducted across southern Australia. It has an industry herd component and a research station component being run simultaneously. Early results from the research stations show that selection for traits affecting body composition holds across seasons and nutrition treatments, and that genetically leaner cows seem to be less fertile, especially under low nutrition. Results are peer-reviewed and compiled for industry dissemination in the Maternal Journal available through the Beef CRC website (www.beefcrc.com.au)

Time Average Maximum Velocity according to PERI and PREconception diet.

<p>Mean (±SEM) Time Average Maximum Velocity (TAMV; cm/s) in heifers carrying male (M) and female (F) fetuses according to A) PERIconception diet Low (7%CP; M n = 20 and F n = 8) and High (14%CP; M n = 25 and F n = 11) from 60d prior to conception to 23dpc in Experiment 1 and B) PREconception diet Low (10%CP; M n = 13 and F n = 3) and High (18%CP; M n = 7 and F n = 11) from -60d to conception in Experiment 2; * denotes P≤0.05.</p

Post-mortem fetal heart weight according to PERIconception diet.

<p>Mean (±SEM) post-mortem fetal heart weight (g) in male (M) and female (F) 98-day-old fetuses from heifers fed Low (7% CP, M n = 9 and F n = 10) or High (14% CP, M n = 16 and F n = 11) PERIconception diet from day 60d prior conception to 23days post-conception.</p

Pulsatility Index according to PERIconception diet.

<p>Pulsatility Index (mean ±SEM) by PERIconception diet (■ Low 7%CP and ● High 14%CP) from 60d prior to conception to 23dpc in Experiment 1 in male (Low n = 20 and High n = 25) and female fetuses (Low n = 8 and High n = 11). * denotes P≤0.05.</p

Crown-Rump length and the Biparietal Diameter at 60dpc according to POSTconception diet.

<p>Mean (±SEM) crown-rump length (CRL, cm) at 35dpc and biparietal diameter (BPD, cm) at 60dpc in pregnant heifers that received a High (14% CP; n = 25) or Low (10% CP; n = 24) protein diet during the POSTconception period (conception, day 0) to 90d post conception in Experiment 2. * indicates P<0.05.</p

Heart rate at birth according to sex and PERI and PREconception diet.

<p>Heart rate (mean beats/min ±SEM) at birth of male and female calves from heifers fed Low (7% CP; n = 28) or High (14% CP; n = 36) PERIconception diet from day 60 prior conception to day 23dpc in experiment 1 (A); and from heifers fed Low (10% CP; n = 16) and High (18% CP; n = 18) PREconception diet from -60d to conception (day 0) diet in experiment 2 (B); * indicates P<0.05.</p