This study evaluated (a) the efficacy of an association between injectable antibiotic therapy and sealant (ATBS) on milk yield (MY), somatic cell count (SCC), and prevalence of intramammary infections (IMI); and (b) the efficacy of gonadotropin-releasing hormone (GnRH) on follicular cyst (FCs) resolution (cyclicity at the 45th day in milk; DIM) and cumulative pregnancy rate (CPR) in heifers submitted to a lactation induction protocol (LIP). A total of 114 crossbred (Holstein × Jersey) heifers, with 34.7 ± 4.8 months and 439 ± 56.35 kg were submitted to LIP. On the 5th day of the LIP, the heifers were assigned to (i) ATBS (n = 57) with 7 mg/kg of norfloxacin associated with sealant and (ii) Control 1 (n = 57; CONT1) with no treatments. Lactation began on the 21st day of LIP and the 15th DIM, FCs were diagnosed and 106 heifers were randomized into two treatment groups with 53 heifers each: (i) GnRH (5 mL injectable GnRH) and (ii) Control 2 (CONT2; no treatment). Of the 114 heifers initially induced, 83.33% (n = 95) responded to LIP with an average MY of 15.19 kg/milk/day during 22 weeks of lactation. In the first 14 DIM, the IMI prevalence was 18% and 28% for heifers ATBS and CONT1 treated, respectively. Additionally, coagulase-negative Staphylococcus was the most frequently isolated group of pathogens. Mammary quarters that received ATBS treatment had a lower risk of IMI and SCC than CONT1. The cyclicity at 45 DIM was 68% (ATBS) and 35% (CONT1), and 57% and 46% for animals in the GnRH and CONT2. CPR was 60% in the ATBS group and 89% in CONT1, but GnRH treatment did not affect the CPR. In conclusion, LIP was effective in stimulating MY in heifers, and the IMI prevalence decreased with ATBS treatment. Also, the use of GnRH did not affect the FC regression, cyclicity at 45 DIM, and CPR.

At present, there is a concern about the quality of milk and diseases related to its consumption, as it can generate discomfort and allergic reactions in some individuals due to its protein components. Thus, the present study was developed to identify the allele and genotype frequencies of genes for β casein, A1 and A2, in dairy herds in the region of Araguaína-TO, Brazil. Genetic material from 421 animals (crossbred dairy cattle in lactation) was used. All animals were numbered for identification, and DNA samples were extracted from hair bulbs. Samples for two markers from the polymorphic regions were characterized and confirmed by real time PCR using the ABI Prism® 7500 Sequence Detection System (Applied Biosystems). Allele and genotype frequencies were determined using the TaqMan™ detection system, where the primer and probe release different fluorescence signals for each allele of the polymorphism. The sampled herd showed frequencies of 28.27% for the A1 allele and 71.73% for the A2 allele. Genotype frequencies were 52.96% (223/421) for A2A2; 37.53% (158/421) for the A1A2 genotype; and 9.50% (40/421) for the A1A1 genotype. The frequency of the A1 allele for β-casein in dairy herds from the northern region of Tocantins was low and is per the results of previous studies. Although the A2A2 genotype of β-casein had a high relative frequency, the A1A2 genotype is still rather frequent, warranting greater selection pressure.

Repeat breeding is a serious reproductive disorder in dairy cattle. The causes of repeat breeding are multifactorial and there are two main mechanisms: failure of fertilisation or early embryo death, mainly due to poor quality of oocytes and an inadequate uterine environment. Many methods have been used to increase the pregnancy rate for repeat breeder cows, such as intrauterine infusion of antibacterial agents or antibiotics, hormonal treatments for oestrus synchronisation and induction of ovulation, and progesterone supplementation or induction of accessory corpus luteum; however, the results were inconsistent between studies. Embryo transfer (ET) has the capability to minimalise the effects of poor oocyte quality and unfavourable uterine environments on early embryo development during the first seven days after ovulation in repeat breeder cows, and several studies showed that ET significantly improved the pregnancy rate in this group of animals. Thus, ET can be considered an option to increase the conception rate in repeat breeder dairy cows.

Johne’s disease, caused by infection with Mycobacterium avium subsp. paratuberculosis (MAP), causes economic losses in dairy herds due to reduced milk production and premature culling. A test-and-cull strategy coupled with changes in calf rearing management preventing new infections has been introduced into infected herds to control MAP prevalence. This study appraised the effectiveness of these practice changes.

The use of 1.16 mg/kg (one third) of the recommended dose of diminazene aceturate, administered indiscriminately to cattle on day seven of the unfrozen <em>Babesia bovis</em> and <em>Babesia bigemina</em> bivalent live blood vaccine reaction, was an infection and block treatment method of immunisation used successfully with no known adverse effect on the parasites or the development of protective immunity. Continuing with this practice after replacement of the unfrozen vaccine with deep-frozen monovalent <em>B. bovis</em> and <em>B. bigemina</em> live blood vaccines resulted in reports of vaccine failure. Laboratory investigation indicated the harmful effect of block treatment in preventing the development of durable immunity against <em>B. bigemina</em> as opposed to the much lesser effect it had on <em>B. bovis</em>. Consequently the practice was no longer recommended. A <em>B. bovis</em> vaccination attempt aimed at controlling the disease of dairy cows in milk (<em>n</em> = 30) resulted in 20% fatalities during the expected vaccine reaction period. The practice of block treating <em>B. bovis</em> was therefore reinvestigated, this time in a field trial using dairy cattle in milk (<em>n</em> = 11). Using 0.88 mg/kg (one quarter) of the recommended dose of diminazene administered on day 12 of the <em>B. bovis</em> vaccine reaction resulted in only two animals (<em>n</em> = 5) testing ≥ 1/80 positive with the indirect fluorescent antibody test (IFAT) although parasites could be demonstrated in three. In the untreated control group, by contrast, five of the vaccinated animals (<em>n</em> = 6) tested ≥ 1/80 positive with IFAT and parasites could be demonstrated in all. The unsatisfactory outcome obtained in this study, combined with that of the earlier investigation, indicated that there are more factors that influence successful vaccination than previously considered. It is therefore concluded that block treatment of the live frozen South African cattle babesiosis vaccines reactions is not recommended.

There is a paucity of published research information on the quality of water used in the Malaysian ruminant livestock production system. Also, there are growing concerns about the sanitation standards of ruminant farms as it affects the management of wastewater in Malaysia. This study was designed to compile preliminary data on the drinking water and wastewater quality in designated dairy cattle farms in the Klang Valley. Seven dairy farms were randomly selected and visited to collect samples of drinking and wastewater for laboratory analysis. The water samples were analyzed to determine dissolved oxygen (DO), pH, salinity, electrical conductivity, turbidity, biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), total dissolved solids (TDS), ammoniacal nitrogen, nitrate, phosphates, total coliform count, iron, and magnesium content. The means of various parameters were compared with the National Water Quality Standards (NWQS) to determine the appropriate classification. We further streamlined the rating of water quality into three broad categories, namely, good (Class I and II), moderate (Class III) and unsatisfactory (Class IV and V). Analysis of drinking water revealed 1(14.29%), 2 (28.57%), 2 (28.57%) and 2 (28.57%) farms were categorized as Class II, III, IV and V, respectively. Meanwhile, all the wastewater samples analyzed in this study were classified as Class V. This study provides preliminary data on the quality of drinking and wastewater in select dairy cattle farms in Malaysia. The obtained findings indicate that the quality of drinking water in most of the cattle farms is below the National Water Quality Standards.

The twinning rate in a herd of Holstein dairy cattle and its effect on lactation and calf performance was investigated by using records of 5815 calving events. Data from twin calving Holstein cows in (TEC-DAP) farm in Al-Fayum Governorate between January 1997 and April 2008 were compared to those giving singles to study the differences in subsequent milk yield, previous and subsequent lactation and dry period length, as well as calf performance. The obtained average twinning rate was 1.4% during the period of the study. Cows giving twins had a significantly (p<0.01) lower daily, peak and 305-d milk yields than those with singles. There was no significant difference (p>0.05) in previous and subsequent lactation and dry period length between cows calving twins or singles. Calves born as twins were significantly (p<0.005) lighter at birth and weaning time than single calves, whereas total birth weight and total weaning weight were significantly (p<0.005) increased for twins than singles. Daily body weight gain from birth to weaning was significantly lower (p<0.005) for twin than single calves. Twinning in dairy cattle has a negative depressive effect on subsequent milk yield. Calf weight produced at weaning per cow calving can be increased in cows producing twins relative to cows producing singles. Alleviation of twinning constraints including dystocia, reduced calf survival and low reproductive performance requires improved management practices and early diagnosis of cows gestating twins in order to provide higher nutritive requirements in the last trimester of gestation and proper timing of drying off, and for higher assistance requirements at parturition. Thus, due to the increased disadvantages which did not offset the additional returns earned by calves, twinning in dairy cattle via selection or artificial induction appears not to be desirable.

Objectives: Left displaced abomasum (LDA) is a common postparturient condition of high yielding dairy cattle. The diagnosis of LDA is challenging and has historically been based on findings that are not specific to the condition. The objective of the current study was to investigate the diag¬nostic performance of ultrasonography (USG) in the clinical management of dairy cows identified with left-sided ping sound postpartum. Materials and methods: Cows with reduced appetite postpartum and had audible left-sided ping sounds on abdominal auscultation were eligible to be prospectively recruited onto the study. The results of clinical findings and abdominal USG were recorded along with milk &#946;-hydroxybutyrate levels, pH levels of abomaso/rumenocentesis samples, and findings on exploratory laparotomy. The diagnostic performance of USG and other clinical investigations was assessed by calculating the test sensitivity and specificity using exploratory laparotomy as a gold standard test. Results: A definitive diagnosis of LDA was made in 23 cows, 8 cows were diagnosed with peritoni¬tis, and 4 cows with frothy tympany. The USG findings that were consistent with LDA were present in all cattle diagnosed with LDA at exploratory laparotomy. The USG findings over the past three intercostal space characteristics of LDA, however, were also present in five cases subsequently diagnosed with peritonitis and in all cases diagnosed with frothy tympany on exploratory lapa¬rotomy. The pH of abdomaso/rumenocentesis samples yielded the highest diagnostic accuracy (97.14%) as a single test in the current study. Conclusions: USG over the left abdominal wall despite being a highly sensitive test for the diagno¬sis of LDA has limitations as a diagnostic tool due to suboptimal specificity. [J Adv Vet Anim Res 2020; 7(2.000): 308-313]

The present work aimed to observe the infection pattern of Bovine herpes virus-1 (BoHV-1) in dairy cattle with reproductive problems in Sudan. A total of 140 samples comprising of vaginal swab (n=97), placenta (n=15), whole blood (n=19), uterine fluid (n=1), and serum (n=8) were collected from 16 dairy herds showing particularly high rate of abortion and infertility in Khartoum State. The samples were used for virus isolation, and were tested by Enzyme-Linked Immunosorbent Assay (ELISA) and polymerase chain reaction (PCR). No virus could be isolated from the samples inoculated for isolation in cell culture. Out of 80 specimens tested by ELISA, 7 (8.75%) were found to be positive, and one sample was doubtful. Using PCR, 11 (10.7%) out of 103 samples were found to be positive. When comparing between two methods for DNA extraction, the DNA extracted by commercial kit was found to be better in quality as compared to the DNA extracted using phenol/chloroform/isoamyl-alcohol method. The study confirmed the presence of BoHV-1 in cattle farms with reproductive problems in Sudan.

A cross sectional survey was carried out in dairy farms in four States of Sudan to determine prevalence of reproductive health disorders that affect dairy cattle industries in the country. A total of 575 adult female cows in dairy farms located in Khartoum, Gezira, Sennar, and White Nile States were investigated using questionnaire survey and face-to-face interviews with the owners. The results indicated that 24.4% of the animals were affected with one or more reproductive health disorders. Abortion (57.1%) represented the major health problem affecting calf yield, followed by infertility (34.3%) and neonatal death (8.6%). Other health problems included stillbirth, vaginitis and retained placenta, anomalies, metritis and repeat breeder. Most of the abortion cases were detected during third trimester (76.25%) followed by first (12.5%) and second (11.25%) trimesters. Finally, countrywide investigations of reproductive disorders and increasing awareness to the owners are recommended for designing successful control strategies of reproductive disorders in Sudan.