A review on reproductive biotechnologies for conservation of endangered mammalian species.

https://dadun.unav.edu/bitstream/10171/37569/3/Review%20PRESENCIAmicotoxinas%20en%20leche%20animal.pdf

Presence of mycotoxins in animal milk: A review

The veterinary clinics of north America: food animal practice.

In comparison to monogastric species, ruminant animals are generally considered to be less susceptible to the adverse effects caused by contamination of feeds with mycotoxins. This is based on the assumption that the rumen flora degrade and inactivate mycotoxins, thus protecting the animal. A number of mycotoxins, however, resist rumen degradation, causing distinct clinical signs of intoxication. Moreover, due to their complex diet, dairy cows may be exposed to a varying number of mycotoxins, originating from different feed materials such as roughage and concentrates. Exposure to these complex mixtures of mycotoxins may result in unexpected health risks. Due to a pre-existing negative energy balance, cows in the transition period are considered to be particularly sensitive to the exposure to feeds contaminated with moulds, fungal spores and mycotoxins.

The role of mycotoxins in the health and performance of dairy cows

Body condition scoring of sheep was first developed as a technique in the 1960s. Unlike live weight, it circumvents the issues of skeletal size, breed and physiological state and is not influenced by gut fill or the length and wetness of the fleece. This review outlines the use of the technique and the relationships between body condition score and other physical measures. In addition, it summarises the literature, across a range of breeds and environments, on the effects of body condition score on reproductive and lactational performance, and the growth and survival of the offspring to weaning. We have proposed that while the relationship between body condition and production traits is positive, it is unlikely to be linear. Where appropriate, the review outlines areas that would benefit from further research. Finally, it outlines what a suitable body condition score profile might be for a ewe over the entire breeding cycle.

https://www.tandfonline.com/doi/pdf/10.1080/00288233.2013.857698

Review of sheep body condition score in relation to production characteristics

Excretion of aflatoxin M1 in milk of dairy ewes treated with different doses of aflatoxin B1.

The aim of this article was to develop a fast and easy duplex polymerase chain reaction (PCR) method, for sex determination of ovine in vitro produced embryos prior to implantation. We tested the approach with 107 samples of autosomal cells (oviductal sheep cells and male lamb fibroblasts), divided into three groups for each sex according to the number of cells employed (30, 5, 2, respectively). We then used the test on 21 embryos at blastocyst stage. On the same day the embryos were transferred in pairs into 11 recipient synchronized ewes. The PCR utilized two different sets of primers: the first pair recognized a bovine Y-chromosome-specific sequence (SRY), that showed 100% homology with the corresponding sequence of the ovine Y-chromosome and is amplified in males only. The second pair recognized the bovine 1.715 satellite DNA (SAT) which was amplified in all ovine samples but, when submitted to the GenBank database did not show homology with any of the reported ovine sequences. However, after sequencing, ovine amplification product showed 98% homology with the bovine specific satellite sequence. The autosomal samples were amplified with 85.0% efficiency and 91.2% accuracy, while amplification was successful with all 21 embryos (100% efficiency). Eight lambs were born and the sex as determined by PCR corresponded to the anatomical sex in seven (87.5% accuracy). These results confirm that this method can be applied in ovine breeding programs to manipulate sex ratio of offspring.

Sexing of in vitro produced ovine embryos by duplex PCR.

The objective of this study was to determine the effect of Vitamin E (Vit E) and Selenium (Se) on semen quality, sexual activity, packed cell volume (PCV), and white blood cell counts (WBC) of Awassi rams during the hot season. Twelve Awassi rams were subdivided into three groups and treated for 90 days. Rams in the 1st group (T1) were treated twice weekly with 175 mg/ram vitamin E at intervals of 12h; rams in the 2nd group (T2) were treated on the same schedule with 70 mg/ram vitamin E plus 2800 mg selenium; and rams in 3rd group (T3) served as controls. Sperm quality (percentage of motile cells and percentage of morphologically normal cells) and quantity (sperm volume, and concentration) were recorded weekly. Sexual activity was tested by using the pen libido test at monthly intervals. Blood samples were taken before treatment and after the 1st, 2nd, and 3rd months. Semen quality was significantly affected by treatments: the ejaculate volume increased in T2 vs T1, and T3; mass activity and individual motility were increased in T1 and T2 vs T3. Sperm concentration was increased in T2 and T1 vs T3, and the percentage of dead and abnormal spermatozoa was reduced in T1 and T2 vs T3, though the differences were not statistically significant. Pen libido test showed reduced reaction time for the first mount in the 1st month in T2 and T1 vs T3. The number of serves was increased in groups T1 and T2 vs T3. There were no significant differences in PCV among groups. After 3 months from the beginning of treatments, the percentage of lymphocytes increased in T1 and T2 vs. T3, while the percentage of neutrophils was reduced in T2 vs T3 in the 2nd and 3rd months. The results of this experiment indicate that treatments with vitamin E alone or in combination with selenium improved semen characteristics and reproductive performance of Awassi rams during the hot season.

Does Vitamin E or Vitamin E plus Selenium improve reproductive performance of rams during hot weather

Decreasing dietary NFC concentration during mid-lactation of dairy ewes: Does it result in higher milk production?

Ten Sarda dairy ewes (5 with high Body Condition Score: H-BCS, BCS>2.5; BW 48.8±5.4 kg; 5 with low BCS: L-BCS, BCS<2.5; BW 36.2±4.7 kg) were subjected, after 7-day preliminary (Prel) period, to short-term feed restriction (FR, 50% of nutrient requirements) for three days followed by refeeding (Re-Fed, 100% requirements) for three days. Milk yield and composition (protein, fat, lactose, MUN, SCC, fatty acids), and blood parameters (glucose, NEFA, BUN, insulin, GH, IGF-I, leptin) were monitored. Milk yield decreased during FR in both BCS groups: at day 3 it was 38% and 35% of Prel values in HBCS and L-BCS ewes, respectively, reaching Prel levels at Re-Fed in both groups. Milk fat concentration was influenced by BCS¥sampling, increasing in H-BCS ewes during FR, but not varying in L-BCS ewes throughout the trial. During FR, milk protein increased as milk yield decreased. There was no change in milk urea nitrogen concentration during FR, but this decreased in both BCS groups during Re-Fed. FR modified the FA profile of milk fat in both BCS groups, increasing LCFA at the expense of SCFA and MCFA. Some blood parameters (NEFA, GH and IGF-I) were influenced by BCS, whereas almost all parameters were influenced by sampling. There was a rapid return to initial levels in all parameters except milk urea, blood urea and insulin at Re-Fed.

Effects of short-term feed restriction on milk yield and composition, and hormone and metabolite profiles in mid-lactation Sarda dairy sheep with different body condition score

Giovanni Cristoforo Bomboi

Papers

Excretion of aflatoxin M1 in milk of dairy ewes treated with different doses of aflatoxin B1.

Sexing of in vitro produced ovine embryos by duplex PCR.

Does Vitamin E or Vitamin E plus Selenium improve reproductive performance of rams during hot weather

Decreasing dietary NFC concentration during mid-lactation of dairy ewes: Does it result in higher milk production?

Effects of short-term feed restriction on milk yield and composition, and hormone and metabolite profiles in mid-lactation Sarda dairy sheep with different body condition score