Summary:  Cows with fertility problems were treated with hormones for ten days or left untreated. All were then artificially inseminated.

Procedure: Phantom cows (non-pregnant cows that do not show fertility signs) were treated with a 10-day progesterone-based synchronisation program before artificial insemination. Untreated phantom cows were used as control. No Animal Ethics Committee application is stated; maybe it was unnecessary as the farmers simply incorporated suggested procedures into their routines.

Purpose:  To test if a progesterone-based synchronisation program is cost-effective to avoid phantom cows. Phantom cows are animals who are inseminated, do not show oestrus signs, but don't become pregnant. These animals can impact profits for farmers. 

Source: Journal article

Year published: 2020

Summary:  Pregnant cows were fed with or without a specific feed additive. After birth, all were fed the same diet. Blood samples were taken in the weeks around birth.

Procedure: Cows in late pregnancy were grazed on pasture and supplemented with maize silage for about two weeks before calving. The silage contained Zeolite A (synthetic sodium aluminosilicate) or nothing as control. After calving, all animals received the same diet without zeolite, but calcium carbonate was added for four days after calving. Blood samples were taken before, during, and after calving.

Purpose:  To test zeolite as a late-pregnancy supplement against hypocalcemia (low calcium). An estimated 40 to 65% of dairy cows get hypocalcemia at the start of lactation, which is a health risk and reduces productivity. Zeolites are minerals that can bind calcium, so it passes the digestion tract unused. The created lack of calcium is supposed to release hormones that get more calcium out of the food.

Source: Journal article

Year published: 2020

Summary:  Some cows in several dairy herds were selected, and their vaginal discharge was measured and sampled. They were then impregnated as per standard agricultural practice.

Procedure: Around 40 animals per herd were chosen in 100 dairy cow herds. They were checked for any diseases before the mating season and excluded if they were pregnant or sick or if the farmer intended to kill them soon. The vaginal discharge was measured using a rubber scoop attached to a steel rod, and a uterine swap sample was taken (using a brush mounted on a stylet). All animals were artificially impregnated, and bulls were introduced to the herds after. A transrectal pregnancy diagnosis was made. The study concludes that at least 20% of cows have endometritis before mating season.

Purpose:  To estimate the percentage of NZ dairy cows with endometritis, and to see if the test method influences the result. Endometritis reduces fertility and, therefore, productivity.

Source: Journal article

Year published: 2020

Summary:  Newborn calves were raised on various milk, pasture, and pellets combinations. They were slaughtered at two years old, and their “quality” was measured.

Procedure: Two hundred calves up to two weeks old were fed either:
a) a high milk diet with unlimited access to pasture before weaning at 12 weeks or
b) a low milk diet with pelleted concentrates before weaning at 7 to 8 weeks.
All calves were disbudded at 10 weeks and had unlimited access to a high- or low-quality pasture from weaning until 7 months old. From 7 months to slaughter at around two years old, all animals were treated the same, pasture-based with silage feeding. They were weighed regularly until standard commercial slaughter (electrical stunning and cutting their throat). Their stature and meat quality were recorded.

Purpose:  To study the effect of different feeding plans on weight gain and meat quality of cross-bred calves. Breeding beef bulls to dairy cows and raising the calves reduces the need to keep and maintain beef mother cows. Changes to the calves’ diet were supposed to speed up their rumen development so that they gain more weight before winter.

Source: Journal article

Year published: 2020

Summary:  The horn buds of young calves who were slightly sedated were burned off with a hot iron. Half of them received pain meds beforehand, and blood samples were taken before and after. After 24 hours, the second group received pain meds, too.

Procedure: Calves scheduled for routine horn disbudding at about one-month-old were divided into two groups. One group received pain relief before the procedure; the other did not. All calves were sedated and disbudded with a hot cautery iron. Blood samples were taken from all calves just before disbudding and twice after. The pain medication was given to the second group of calves after the final blood sample the next day.

Purpose:  To test the influence of pain medication on gene expression related to inflammation when calves are disbudded (removing their horn buds). Injured cells produce proteins called cytokines that increase the inflammatory reaction. Pain meds can decrease the related gene expression. They may also influence other genes in that pathway (for example, some growth genes).

Source: Journal article

Year published: 2020

Summary:  Two newborn calves from a C-section teaching class were unresponsive. They were treated with a technique known to work for horses.

Procedure: As part of a veterinary teaching exercise, ten calves were delivered by C-section. Two of those calves showed indifference to their surroundings, could not find the udder and refused to suckle (a condition called neonatal maladjustment syndrome). Both calves were treated successfully with a method used for foals with this condition:
A soft cotton rope was looped around their thorax three times, and pressure was applied to it for 20min. After the tension was loosened, both calves were more alert and exhibited normal behaviour within a day.

Purpose:  To present results of first aid for c-section calves who struggled to adjust. Two calves delivered during a C-section teaching class showed neonatal maladjustment syndrome (problems adjusting and breathing). This was treated like it would have been in foals.

Source: Journal article

Year published: 2019

Summary:  Regular blood samples were taken from cows on three different farms. Only some were treated against the parasite. Milk production and fertility were recorded.

Procedure: Three dairy farms were selected based on their risk level regarding Ikeda infections (located in high, medium and low-risk areas). Farms were visited monthly for the whole milking season (August to April/May), and the low-risk farm was visited every other month. At each visit, blood samples were taken from the same cows. Milk production and fertility data were recorded. One farm treated some animals with buparvaquone; three of these cows were part of this study. One died shortly after treatment, and another was slaughtered.

Purpose:  To estimate the infection rate with Ikeda of dairy herds in NZ. The parasite lives in the blood and spreads mainly through ticks. Ikeda infection is currently the principal cause of bovine anaemia in New Zealand. It decreases productivity and fertility before becoming chronic and often asymptomatic. The one existing drug against Ikeda (buparvaquone) leads to long waiting periods before meat or milk can be sold, so it’s a severe threat to profit.

Source: Journal article

Year published: 2019

Summary:  New mother cows had blood samples taken. If the sample was negative for a diarrhoea virus, they were sampled again after a while.

Procedure: Over 1,000 cows with their first calves were chosen, and blood samples were taken from the mothers. All animals with a negative test result for antibodies against the diarrhoea virus were resampled later. Farmers filled out a questionnaire about their farming practices and management.

Purpose:  To study how diarrhoea infections spread in grazing beef cattle. These rates would be lower than for intensively farmed dairy cows. Animals might not have enough immunity before pregnancy (when the infection will be passed to the unborn calf). The calf becomes persistently infected, shedding large amounts of virus material throughout its life.

Source: Journal article

Year published: 2019

Summary:  Udders of dairy cows were slightly cut with a scalpel, and a tissue sample was taken with a biopsy needle.

Procedure: Tissue samples were taken from lactating dairy cows’ udders for genome sequencing. An incision is made with a scalpel, and a tissue sample is taken with a biopsy needle about 5cm deep. The researchers also mention samples from a genome-wide association study performed on 65,500 mixed-breed dairy cows without note of the type of sampling.

Purpose:  To find a gene location responsible for stature. The researchers expected a link between mammary and stature gene encoding. A specific gene for body frame and udder would be used for selective breeding.

Source: Conference proceedings

Year published: 2018

Summary:  Pregnant cows were fed a fertiliser component at different concentrations. Blood and urine samples were taken from some animals. Four cows lost their unborn calves, and eight cows died/had to be killed.

Procedure: Cows who were between 3.5 and 5 months pregnant received different amounts of dicyandiamide in their morning feeding (none at all, calculated maximum dosage in farming practice, three times the maximum, and five times the maximum). Daily health checks were performed, and blood and urine samples were taken from selected animals. Visibly ill cows were tested further and treated. Signs of poisoning included rash, low white blood cells or platelets, fever, weight loss, dehydration and depression. Later dissections showed inflammation, ulcers, and abnormal lymph nodes. Four of the treated cows miscarried. One cow on the highest dosage became ill on day 28 and died four days later. Seven other animals became sick, so they had to be euthanised. Dicyandiamide treatment was stopped earlier than planned, but symptoms persisted for several weeks.

Purpose:  To test if dicyandiamide is too poisonous for pregnant cows. Dicyandiamide is an ingredient for plastic, fertiliser and chemical production. It inhibits the breakdown of ammonium and could be used to limit nitrogen loss from grazing cattle into groundwater.

Source: Journal article

Year published: 2018