G. Succi

A case of azoospermia in a bull carrying a Y-autosome reciprocal translocation

During normal cytogenetic investigations on the Chianina cattle (BTA) breed, a normal looking young bull was found to carry an abnormal Y chromosome which was a product of a reciprocal translocation between chromosomes Y and 9. This was revealed by both CBA- and RBG-banding techniques and was clearly confirmed by FISH-mapping analysis with IDVGA50 (which paints the complete Yq arm in a normal Y), as well as with AMD1, CGA, IGF2R (mapping to BTA9q16, BTA9q22 and BTA9q27→q28, respectively) and SRY (mapping to normal BTAYq23). Analysis on sperm from four different samples revealed azoospermia in the carrier, indicating that the rcp(Y;9) induces sterility in the bull.

A new balanced autosomal reciprocal translocation in cattle revealed by banding techniques and human-painting probes

Three hundred and twenty-two (264 males and 58 females), randomly sampled Grey Alpine cattle individuals from Northeastern Italy, were investigated cytogenetically by both conventional chromosome staining and R-banding. Two hundred and eighty-one (87%) individuals had a normal karyotype and 41 (13%) carried chromosomal aberrations such as (a) rob(1;29) in two individuals, (b) rob(26;29) in 36 individuals, (c) XX/XY-chimerism in two individuals, and (d) an abnormally long chromosome in one individual. All these aberrations except (d) have been described before. GBG-, RBG-, CBA-banding and sequential GBG/CBA- and RBG/CBA-banding techniques revealed that the abnormally long chromosome was the result of a reciprocal translocation between chromosomes 1 (q21→qter) and 5 (q11→q33), as confirmed also by chromosome painting with human chromosome 3 and 12 probes. The dam of the carrier bull carried the same translocation, while the grandam showed a normal karyotype. Since the sire of the dam was not available for study, no conclusion about the origin of the chromosome translocation could be drawn. The carrier bull was eliminated because of poor fertility. The dam had three other calves, which all were chromosomally normal. On average the dam had to be served 2.5 times (breed average was 1.2) to be in calf.

A new case of reciprocal translocation in a young bull: rcp(11;21)(q28;q12)

Routine cytogenetic investigations of the Chianina cattle (BTA) breed revealed the presence of longer and smaller chromosomes than the largest (BTA1) and smallest (BTA29) chromosomes in the cells of a young, normal-looking bull used for reproduction. Application of both RBA-banding and Ag-NOR techniques, as well as the use of the FISH technique and specific molecular markers of both BTA11 (IL1B, ASS and LGB) and BTA21 (SERPINA and D21S45) established that these two abnormal chromosomes were the product of a reciprocal translocation between BTA11 and BTA21. Both der(11) and der(21) were C-band positive and the chromosome regions affected were rcp(11;21)(q28;q12). The young bull had a normal body conformation, including external genitalia, normal levels of testosterone (as in the control) and non-detectable levels of both 17 beta-estradiol and progesterone (as in the control). The animal never showed libido in the presence of both males and females in oestrus. After slaughter at 18 months, histological evaluation revealed normal organized testes, seminiferous tubules and epididymis but with poor proliferative germ cells consisting mainly of spermatogonia, middle pachytene spermatocytes and early spermatids with late spermatids and spermatozoa being very rare.

A new autosomal translocation in " Alpine grey cattle "

In the cytogenetical research experiments at present carried out in Italian cattle breds which are in way of numerical decrease, we have taken into consideration a sample number of 5o bulls of the « Grigia Alpina breed n, chosen out of a group coming from an A.I. Centre and from those which were selected for reproduction purposes at the Pure Breed Show. Five bulls resulted to be carriers of a new autosomal translocation involving two of the smallest chromosomes. On the basis of the results obtained by need of measurements and the application of banding, we are of the opinion the translocation concerns the chromosomes of the pairs 25 and 27 . Two of the translocation carriers, kept at an A.I. Centre have never given semen suitable for freezing purposes.

Première étude cytogénétique dans un centre italien d'insémination artificielle

Une étude cytogénétique a été entreprise sur 39 taureaux d’un centre d’insémination artificielle en Italie. Aucune anomalie chromosomique de nombre ou de structure n’a été identifiée, mais un animal de race Holstein Friesian a été trouvé porteur d’un chimérisme XX/XY. Il présentait 52 ,38 p. 100 de cellules femelles, une fertilité réduite par rapport à la moyenne du centre et un sex-ratio modifié en faveur des femelles.

THE IDIOGRAM OF THE DOMESTIC HORSE (EQUUS CABALLUS L.)

SUMMARYThe idiogram of the domestic horse is established by measuring 20 cells (10 male and 10 female cells) derived from 10 horses. A practical classification of the karyotype according to size and morphology of the chromosomes is proposed.

Milk ejection during automatic milking in dairy cows

Riassunto L’eiezione del latte nei sistemi automatici di mungitura. L’effetto della frequenza e della routine di mungitura sui parametri delle curve di eiezione del latte è stato valutato in due aziende con sistema automatizzato. Sono stati misurati su 158 bovine i parametri di 1252 curve di emissione del latte, ottenute per singolo quarto utilizzando flussometri elettronici mobili (Lactocorder). Mediamente gli animali sono stati munti 2,2 e 2,6 volte al giorno nelle due aziende. Il tempo necessario per il lavaggio e l’attacco dei singoli capezzoli (147 s) ha consentito una regolare messa a latte. Dalle curve di emissione emerge che la durata totale della mungitura e la fase di plateau aumentano all’aumentare dell’intervallo dalla mungitura precedente e al grado di riempimento della mammella, mentre le fasi di ascesa e di discesa non sono influenzate né dall’intervallo né dal riempimento. La bassa percentuale di curve bimodali ottenute e la brevità delle fasi di discesa indicano una corretta capacità di mungitura del sistema robotizzato.

Nouvelles observations sur une translocation robertsonienne en race bovine romagnole

Dans le principal centre italien d’insémination artificielle (Cesena, prov. Forli) de la race Rornagnole, une étude cytogénétique préliminaire sur les neuf taureaux utilisés a montré chez deux d’entre eux un nombre de base des chromosomes réduit à 59 , avec la présence d’un chromosome submétacentrique conséquence d’une translocation 1/29 . Ces deux taureaux porteurs de l’anomalie, sans aucun lien de parenté, étaient phénotypiquement normaux et avaient une fertilité normale.

Classical and molecular cytogenetic studies in some cattle breeds

Riassunto Studi di citogenetica classica e molecolare in alcune razze bovine. Sono riportati gli studi intrapresi per caratterizzare citogeneticamente alcune anomalie cromosomiche legate a sterilità o a ipofertilità in alcuni bovini di razza Chianina, Marchigiana, Romagnola, Maremmana Grigio Alpina e Podolica. Sono state impiegate sia tecniche di citogenetica classica (bandeggio cromosomico) che molecolare (tecnica FISH) con specifici marker molecolari per indagare le seguenti anomalie cromosomiche: fusioni centriche, traslocazioni reciproche e inversioni pericentriche. Studi con il marker molecolare INRA143, che mappa nella regione pericentromerica del cromosoma 29, hanno evidenziato chiari segnali di ibridazione nella parte prossimale del braccio q di tale traslocazione, supportando l’ipotesi che questa traslocazione si sia formata per fusione centrica dei cromosomi 1 e 29 e per inversione pericentromerica del cromosoma 29. Sono stati condotti studi su alcuni animali giovani, alcuni dei quali risultati sterili o ipofertili e portatori di traslocazioni reciproche e di un inversione pericentrica al cromosoma Y

Effect of season on nutritive value of an Alpine pasture

Abstract Pasture is the cheapest source of nutrients for dairy cows, but supplementation with energetic concentrate can balance a diet with low energy/nitrogen ratio at the beginning of the grazing season or a low energy content at the end of the grazing season. Aim of this study was to evaluate the effect of seasonal variation and botanical composition on nutritive value of an alpine pasture over 3 grazing seasons. In 22 ha alpine pasture (Prà Maslino, SO, 1650 m s.l.) most important botanical species (20) were sampled every 15 days through the 3 seasons (194 samples) and were analysed for chemical composition and Gas Production. Two types of botanical association included the most important part of pasture sward: Festuca rubra (47%) and Trifolium repens (44%), with 91 different species. Gramineae species had more DM content (38.6 ± 12.1% as fed), NDF (67.9±8.6% on DM) and ADF (36.0±6.4% on DM) but less CP (10.4±3.0% on DM) than every other species (DM 27.7±10.5% as fed; NDF 52.5±11.2% on DM; ADF 33.8±7.2% on DM; CP 15.0±5.4% on DM). From June to September plant growth determined a decrease of quality, although there was a great variability for species and year of trial (average daily decrease of 0.5 g/kg DM for CP, average daily increase of 1.2 g/kg DM for NDF, while for gramineae species OM digestibility decreased 0.25%/d and 0.18%/d for other species). Multiple regressions of dOM on several analytical parameters were performed and the best significant equation for all samples was: dOM = 98.13 - 0.5305 DM (%) - 0.6071 ADF (% DM) (n=144; R2=0.63; RSD=7.69) According to the Cornell system, sward samples showed a high content of slow-degradation carbohydrate fraction “b2” (46.0±6.8% CHO) and a high content of medium-degradation protein fraction “b2” (75.1±2.3% CP), while the immediately-available carbohydrate fraction “a” was 22.3±1.2% CHO, and the immediately-available protein fraction “a” was 19.1±2.3% CP. These data suggest that grazing dairy cows need concentrates which takes into account the high protein content and fermentability of pasture at the beginning of the grazing season, and the low energy and protein content of pasture at the end of the grazing season.