Influence of circadian rhythm, breed, stage of lactation, milk yield and parity on body and udder skin surface temperature of lactating cows monitored by infrared thermography

ABSTRACTThe objective of the study was to establish baseline thermographic information on body and udder skin surface temperature (USST) of lactating cows in different stages of lactation, milk yield, parity, breed and season. Holstein Friesian crossbred (n = 19 cows) and Deoni lactating cows (n = 14 cows) were monitored for body (i.e. eye) and USST prior to milking using a forward looking infra-red (FLIR) camera. It was observed that the mean body and USST of both crossbred and Deoni cows did not differ significantly. The body and USST of both the breeds were significantly higher by 0.9–1.0°C during evening than morning milking. There was no difference in body and USST between days and between udder quarters. Similarly, stage of lactation, milk yield and parity did not show any influence over body and USST. The body and USST were higher in summer (1.1°C) than in spring and winter seasons. Deoni cows had 1.0°C lesser body and USST than crossbred cows. It is concluded that baseline thermographic information on body and USST would be useful in developing breed-specific thermographic signature for individual animal

Effects of pedigree and exotic genetic inheritance on semen production traits of dairy bulls

Objective: To study the effects of different levels of exotic inheritance on ejaculate quality in bulls and its passage through different generations. Methods: Data on semen production traits and ejaculate quality were obtained for 38 crossbred bulls and grandsire-sire-progeny relationship in relation to semen quality was studied. The bulls were classified into three groups based on the level of exotic inheritance viz. F1, 50.0%-62.5% exotic germplasm and >75% exotic germplasm. Results: Results of the present study indicated that about 40% of the ejaculates obtained from the crossbred bulls were rejected from further processing due to poor ejaculate quality. The F1 bulls produced significantly higher proportions (57.00±10.00) of poor quality ejaculates compared to the interse mated bulls. The age at first semen collection in crossbred bulls ranged from 567 to 1 010 days with an average of 738.89±18.18 days while the mean age at first semen freezing was 865.72±34.60 days. Conclusions: It may be inferred that the “acceptable quality semen producing ability” decreased from grandsire through sire to male progeny and among the increasing exotic genetic levels of CB cattle, F1 bulls produced significantly higher “low grade ejaculates” that were unfit for cryopreservation

Testicular cytology indicates differences in Sertoli cell counts between “good freezer” and “poor freezer” bulls

17-25<span style="font-size:11.0pt;font-family: " times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">In artificial insemination, poor quality of semen unsuitable for cryopreservation and susceptibility of spermatozoa to cryodamage in crossbred bulls have been a matter of concern. Present study was designed to identify the testicular cytology indices that might be used to predict the semen quality and cryotolerance of spermatozoa in bulls. Based on the ejaculate rejection rate and sperm cryotolerance, bulls (Holstein Friesian X Tharparkar crossbred) were classified into either good (producing good quality semen with spermatozoa having good cryotolerance; n=4) or poor (producing poor quality semen with spermatozoa having poor cryotolerance; n=4). Testicular cytology was studied in all the 8 bulls using fine needle aspiration technique. Testicular cytology of good bulls and poor bulls differed significantly. The proportion of Sertoli cells was significantly higher in good bulls (25.3±1.6) compared to poor bulls (11.0±0.8). The Sertoli cell index was 46.1±5.0 in good bulls while it was only 13.8±1.3 in poor bulls. The cut off values, as determined using Receiver Operating Characteristics analysis, indicate that the bulls having testicular cytogram comprising of <15.5% Sertoli cells, <24.3 Sertoli cell index and >4.0 spermatogenic cells to Sertoli cell ratio might be a poor bull in terms of semen quality and cryotolerance of spermatozoa<b style="mso-bidi-font-weight: normal">. The proportion of Sertoli cells in the testicular cytology had positive (P <0.05) relationship with semen quality and cryotolerance of spermatozoa.</span