Test day milk yield data of 81,653 Jersey crossbred cows reared under farmers’ production system in Tamil Nadu state, over a period of 24 years (1999-2022) were utilised to determine the effects of non-genetic factors viz. agroclimatic zone, period of calving, season of calving and parity on lactation traits.  The production traits considered were 305-day milk yield (305DMY), total lactation milk yield (TMY), 180-day milk yield (180DMY), peak yield (PY), days to attain PY and lactation length (LL), the least-squares means of which were 2458.82 ± 7.02 kg, 2470.77 ± 7.04 kg, 1657 ± 4.71 kg, 10.69 ± 0.03 kg, 73.22 ± 0.56 days and 298.09 ± 0.17 days respectively. The agroclimatic zone had significant (P<0.01) influence on all the lactation traits studied with Western zone having the highest mean (2763.08 kg) for 305DMY followed by North Western zone and Cauvery Delta zone while North Eastern zone had the least (2066.85 kg) milk yield. Both period and season of calving significantly (P<0.01) affected all the traits. The estimated means of 305 DMY, TMY and 180DMY of 2960.99 kg, 2987.38 kg and 1934.75 kg respectively in period P2 (2004-2007) were significantly higher compared to other periods while period P1 (1999-2003) had the least milk production. Cows that gave birth in Northeast monsoon and Summer seasons produced more milk comparatively. Parity also had highly significant (P<0.01) influence on all the traits studied with cows above third lactation producing higher milk yield. The influence of non-genetic factors found on milk production of cows, revealed in this study will be useful in planning future breeding and management interventions for improving the milk production of the Jersey crossbred cattle under farmers’ production system in Tamil Nadu. 

Buffaloes have high productive potential but poor manifestations of oestrus signs and silent oestrus act as a major constraint in buffaloes affecting their reproduction. There are several detection tools used for detection and confirmation of oestrus in cattle but none of the methods have succeeded to overcome the problem of silent estrus in buffaloes. In recent years proteomics approach has gained much attention to identify proteins associated with various physiological and disease conditions in saliva and cervico vaginal fluid mostly in humans and up to certain extent in cattle and buffaloes. In this study twelve pluriparous Murrah buffaloes aged 4 to 7 years with good body condition were selected and divided into group I (regular oestrus), group II (silent oestrus). Each group carries six animals and saliva was collected at proestrus (day -3), oestrus (day 0) and diestrus stage (day 7). Cervico vaginal fluid (CVF) was collected only at oestrum stage. Protein profiling of saliva were studied by SDS - PAGE analysis. The SDS-PAGE analysis showed proteins of molecular weight 150, 110, 80, 40 kDa during proestrus; 150, 120, 70 and 50 kDa during oestrus; 250, 150, 90, 50 and 37 kDa during diestrus in group I buffaloes. Similarly, proteins of molecular weight 250, 150, 100, 80 and 25 kDa during proestrus; 150, 100, 75 and 50 kDa during oestrus and 250, 100,75 and 25 kDa during diestrus were observed  in group II buffaloes. The SDS-PAGE analysis of CVF showed proteins of molecular weight of 100 and 75 kDa in group I buffaloes and 250 and 150 kDa in group II buffaloes. Oestrus specific proteins with different molecular weights were identified in terms of different bands size. However further study is warranted to find out their role during oestrus in regular and silent oestrus buffaloes for the development of specific diagnostic assay.

The study on the assessment of body weight gain in three indigenous chicken breeds viz., Aseel, Kadaknath and Siruvidai chicken were conducted in five poultry farms of Vendhoni village, Ramanathapuram district. The body weight gain both between the breeds and farms were statistically analysed for a period of 20 weeks. All the five selected farms were distributed with day old (0 Day) Aseel, Kadaknath and Siruvidai chicks (Each 10 Nos) and about 50 kg each of commercial chick mash (Nutrikraft®). The body weight gain was recorded and assessed every week until 20 weeks. Among the three breeds analysed, a highly significant difference (P ≤ 0.01) existed with Aseel breed having higher body weight gain (1.441 kg) followed by Kadaknath (0.887 kg) and Siruvidai (0.737 kg) at 20 weeks of age.  The weight gain recorded during fourth and eighth weeks of age showed a highly significant (P ≤ 0.01) change among all the three breeds. The weight gain of Kadaknath and Siruvidai were highly significant (P ≤ 0.01) during 12th and 16th week of age. Whereas the weight gain in Aseel was found to be non-significant (P ≥ 0.05) in the same period of study. During 20th week, Siruvidai showed highly significant (P ≤ 0.01) change in weight gain and Aseel and Kadaknath showed non-significant (P ≥ 0.05) change.  Overall, Aseel had higher body weight gain than Kadaknath and Siruvidai breeds. All the three breeds were found to be well adapted to the hot and humid climatic condition of this district.

The study was conducted to document the incidence and nature of oestrus like signs and follicular biometry during the lunar and peri-lunar days in crossbred cattle. Crossbred cattle (n = 678) which were reported to be with oestrus like signs on lunar days (full moon day and new moon day) and peri-lunar days were subjected for the investigation. Only 60.6 per cent of the animals during the study period were in actual oestrus. The remaining animals (39.4%) were found to be in various reproductive statuses viz., pregnancy (17.7%), mid-cycle oestrum (6.9%) and without any oestrus characteristics (14.8 %). The diameter of the dominant follicle in cattle with oestrus signs during lunar days (10.4 ± 0.2 mm) was significantly (P < 0.05) smaller than cattle in actual oestrus during normal days (12.2 ± 0.5 mm). Exhibition of oestrous signs with smaller follicular diameter indicated the probable chances of lunar influence on the follicular dynamics, steroidogenesis and reproductive characters in cattle. 

Lice infestation is one of the major problems to the duck farming, causing irritation that lead to lowered feed intake, retarded growth, reduced weight gain and decreased egg production. The present communication deals with occurrence of different species of lice in a desi duck from Cauvery delta region of Tamil Nadu. A farmer from Thanjavur district of Tamil Nadu brought five dead two year old native ducks for necropsy at Dept. of Veterinary Pathology, Veterinary College and research Institute, Orathanadu, Tamil Nadu. External examination of ducks revealed presence of 13 lice specimen in one bird. They were examined and identified as Trinoton querquedulae (n= 8), Anatoecus dentatus (n= 4) and Anaticola crassicornis (n= 1) morphologically. This study is the first to establish the presence of mixed lice infestation in native ducks from Cauvery delta region of Tamil Nadu and also first repot of Trinoton querquedulae in ducks from India.

A four-month-old male Labrador retriever puppy was presented to Referral Veterinary Polyclinic, Indian Veterinary Research Institute with the history of anorexia, vomiting, haemorrhagic diarrhoea and signs of hypovolaemic shock. The case was diagnosed as parvovirus gastroenteritis by rapid antigen detection test. Shock was managed by infusion of polyionic isotonic fluid.  Haematological examination revealed severe leukopenia with WBC count of 0.3×10³/µL, which was treated with administration of recombinant human granulocyte colony stimulating factor (Filgrastim) at 5 mcg/kg subcutaneously along with supportive therapy. Dog showed elevated WBC count and improvement in clinical signs after 48 h. Administration of granulocyte colony stimulating factor along with routine therapy enhanced the survivability in canine parvovirus gastroenteritis.

The study was conducted on repeat breeding cows at Large Animal Gynaecology Ward, Department of Clinics, Madras Veterinary College, Chennai and some private cattle farms in and around Koduvalli region, Tiruvallur district, Tamil Nadu. In experiment I, Jersey crossbred cows (n=31) synchronized by PGF2a and inseminated on exhibited estrum. The cows were randomly divided into five groups viz. Group I (control, n=6), group II (n=7,100mg), group III (n=6, 150mg), group IV (n=6, 200mg) and group V (n=6, 250mg) and supplemented with fish meal on day 13, 14 and 15 of post insemination in addition to their routine feed. Pregnancy diagnosis was carried out by rectal palpation on day 60 of post insemination. In experiment II, twelve repeat breeding Jersey crossbred cows were selected and synchronized using PGF2a followed by timed insemination. On day 10 of post estrus, rectal examination was performed to identify the corpus luteum and randomly divided into two group viz. Group I and Group II (control). Group I cows were injected with Meloxicam @ 0.5 mg/ kg body weight through intramuscularly on day 13 to 15 post-insemination. The conception rate in experiment I as in Group I, group II, group III, group IV and group V are 16.67%, 71.43%, 66.67%, 66.67% and 50.0%, respectively. The conception rate in meloxicam treated animal was 66.7% and in control animal was 33.3%. The fish meal treatment and Cox-2 inhibitor in repeat breeding crossbred cows had improved the conception rate. Further, the supplementation of 100mg offish meal in repeat breeding cows has shown higher conception rate as compared to other groups in experiment II. Hence, it may be used in field condition for enhancement of conception rate, however, further studies in larger population is warranted.

Repeat breeding due to sub clinical endometritis (SCE) is often diagnosed by cytological examination and the effect of endocervical inflammation (ECI) on increased hazards ofpregnancy is inadequately investigated. In this study, endocervical cytology was compared with the golden standard test `endometrial cytology' to detect SCE as a cause of repeat breeding in cows. Influx of Neutrophils and endocervical inflammation will reflect the status of endometrium and may indirectly reflects the ongoing sub clinical form of endometrial inflammation. Hence, this study was aimed at fixing threshold for PMN in endocervical cytology and comparing the same with golden standard technique. Repeat breeding cows associated with endocervical inflammation with >8% of neutrophils during standing estrus in endocervical cytology will have increased hazards of pregnancy. Our study suggested that a moderate concordance/association between ECI and endometrial inflammation (EDI) in repeat breeding cows, these findings were based on the endocervical and endometrial cytology. Based on the endocervical cytology examination 85% of repeat breeding cow posses EDI (SCE) with a diagnostic sensitivity of 86% and showing moderate clinical acceptability for application of endocervical cytology as diagnostic aid to detect SCE in repeat breeding cows.

Composite cattle feed samples and raw materials like maize, wheat, sorghum, broken rice, pearl millet, groundnut cake, cotton seed cake, mustard cake, soyabean meal, rapeseed meal, sunflower meal, guar meal, safflower meal, deoiled rice bran and wheat bran were collected from various parts of India for a period 5 years and evaluated for aflatoxin B1 level by screening through ELISA and confirmation through HPLC. Among the 482 composite cattle feed samples, only 68.5per cent were having aflatoxin Bilevel below the permissible level (below 20 ppb). Higher incidence of aflatoxin B1 was recorded in west zone than east, north and south zones during monsoon period. However, it was observed that incidence of aflatoxin B1 at concentration beyond 100ppb was relatively higher in eastern zone both during monsoon and non-monsoon period than the west, north and south zones. Among the energy source, maize had the highest (7.8 per cent, 15 out of 193 samples tested) prevalence of alarming levels of aflatoxin (>100ppb) and 41.5 per cent (80 samples) in the range of 21 to 100 ppb of aflatoxin B1. Only 50.8 per cent (98 samples) were within permissible level (<20 ppb). It was observed that the presence of aflatoxin Biwas more in maize during monsoon in south zone. Only 47.2 per cent of groundnut cake (118 samples) were within permissible level of <20 ppb of aflatoxin B1. In west zone, highest sample profile (15.18per cent) and zone-wise distribution of 45.45per cent was recorded in the samples of groundnut cake having aflatoxin B1 at alarmingly high level of more than 100 ppb. Overall data reveals that monsoon favours development of aflatoxin B1 more during monsoon.

A study was conducted to assess the heat tolerance of crossbred female (n=7) calves of six to twelve months of age for thirty days each in summer, monsoon and winter. Temperature humidity index (THI) was calculated at forenoon and afternoon in all the seasons and heat tolerance was carried out using Iberia heat tolerance coefficient, Benezara coefficient of adaptability and Dairy search index. The highest THI was recorded in summer afternoon while lowest was recorded in winter forenoon. There was a significant increase in THI from forenoon to afternoon in all the seasons. IHTC was within the reference value in winter forenoon while rest of the time it was below the normal. IHTC decreased significantly from forenoon to afternoon in all the seasons. BCA was above the reference value in forenoon and afternoon in all the seasons. BCA increased significantly from forenoon to afternoon in all the seasons. DSI was significantly lower in winter compared to summer. It was concluded that crossbred female calves have low heat tolerance during afternoon in all the seasons.