Hereford Calves Research Articles

Features of growth and meat productivity of Hereford and Kalmyk bull calves

Abstract The purpose of the research is to study the peculiarities of growth and meat productivity of Hereford and Kalmyk bull calves bred in the conditions of the foothill zone of the Central Caucasus. The object of the research were Hereford (group I) and Kalmyk (group II) bull calves. A more complete realization of the genetic growth potential of Hereford cattle took place by the end of the research – at the age of 18 months, when the superiority of animals of this breed over the Kalmyk breed representatives was 22.6 kg (P>0.99). Heavier hot carcasses of Herefords with a difference of 18.8 kg (P>0.99) testified to their greater fullness. As a result of the differences in the mass of the hot carcass and internal fat, the highest slaughter weight and its yield were obtained from representatives of the Hereford breed, who surpassed their peers of the Kalmyk breed in these indicators by an average of 21.4 kg (P>0.99) and 2.8 abs.% (P>0.99), respectively.

295 Development of a model to predict forage intake and growth of nursing beef calves

Abstract Models to predict intake and growth of preweaning calves have received less attention than postweaning calves. The objective was to develop a model to predict forage intake and growth of nursing beef calves. Data on milk intake, forage intake, and body weight (BW) of 51 Hereford calves from birth to 200 d of age were acquired from Boggs (1977). Milk and forage intake equations were those evaluated by Lancaster et. al. (2021; 10.1093/jas/skaa406). Forage digestibility was evaluated with a dataset on in vitro and in vivo measurements. Milk energy concentration was evaluated with a dataset on milk yield and composition. NASEM growth equation was evaluated using the dataset of Hildebrand et al. (2022; 10.1093/jas/skac064.321). Model precision and accuracy were evaluated using the concordance correlation coefficient (CCC) and mean bias (MB). The NASEM and WOOD milk yield equations predicted milk intake reasonably well (CCC = 0.796 and 0.820; MB = 4.29% and 1.31%, respectively); the WOOD equation was used in subsequent analyses. Forage intake prediction was imprecise (CCC = 0.348 to 0.613) and inaccurate (MB = 19.36 to 57.67%). Body weight prediction was moderately precise (CCC = 0.574 to 0.766) and moderately accurate (MB = 6.39 to 15.79%). With observed BW, forage intake prediction was moderately precise (CCC = 0.528 to 0.834) and highly to poorly accurate (MB = 0.81 to 27.56%). With observed forage intake, BW prediction by the NASEM growth equation resulted in CCC of 0.821 and MB of 9.69%. Published equations relating IVDMD to in vivo OMD were imprecise (CCC = 0.437 to 0.520) and moderately to highly accurate (MB = -9.46 to 7.67%). A new equation was developed: OMD, % = 7.7719 ± 4.3825 + 0.8937 ± 0.0772*IVDMD, % with RMSE = 2.803% and R2 = 0.9055. Milk energy concentration changed with days in milk (DIM; P < 0.05) and milk yield (P < 0.05): Energy, Mcal/kg = 0.7525 ± 0.0037 + 0.00069 ± 0.00016*DIM -0.00012 ± 0.00003*DIM*Yield, kg/d with RMSE = 0.031 and R2 = 0.527. Evaluating the NASEM growth equation in beef cattle resulted in CCC of 0.777 and MB of -13.56%. A new equation was developed: EBG, kg/d = 7.9279 ± 0.8254*(RE, Mcal/d/EBW, kg0.75) ^0.7083 ± 0.0385 with RMSE = 0.1127 and R2 = 0.6940. With observed forage intake, BW prediction with new equations resulted in CCC of 0.901 with MB of 1.58%. With the new equations, forage intake prediction by TED06, BAK76, TED09A, TED09B, and HOL82 resulted in CCC of 0.822, 0.700, 0.434, 0.686, and 0.380 with MB of -7.01, -5.08, 36.87, 13.24, and 10.96%, respectively. Body weight prediction resulted in CCC of 0.935, 0.938, 0.896, 0.926, and 0.886 with MB of -7.34, -6.21, -0.09, -5.35, and -9.41%. In conclusion, prediction of forage intake and BW in nursing beef calves were hindered by use of IVDMD, constant milk energy concentration, and the NASEM growth equation.

ДИНАМИКА ЖИВОЙ МАССЫ МОЛОДНЯКА МЯСНЫХ ПОРОД В УСЛОВИЯХ РЕСПУБЛИКИ ТЫВА

The aim of the study is to evaluate the growth and development of young meat cattle in the Republic of Tuva. Objectives: to study the growth and development of young cattle by live weight at birth, 3 and 6 months; to determine the average daily and absolute gains; to take the main measurements and to calculate the body conformation indices. The object of the study was young Hereford and Kalmyk cattle (6 months old). The animals were assessed for appearance, their measurements were taken and body conformation indices were calculated. The obtained data were processed in the MS Excel spreadsheet editor. The study of the dynamics of live weight indicators and growth rates up to 6 months showed an advantage of Hereford calves: live weight at birth – by 4.3 kg; at 3 months of age – by 6.2 kg; at 6 months of age – by 13.8 kg; the average daily gain at the age of 3–6 months is 96 g more, and the absolute gain from birth to 3 months is 6.8 % more, from 3 to 6 months is 11.3 %. In the neonatal and 6-month period, Hereford calves were taller than their Kalmyk peers: by oblique body length – by 5.1 and 7.1 cm; height at the withers – by 7 and 3.9; chest girth behind the shoulder blades – by 5.5 and 4.5 cm, respectively. At 6 months, Kalmyk calves had highly reliable indicators of the leanness index (by 4.1 %), and the Herefords – the bone index (by 9 %). The advantage of the young Hereford breed in all the studied indicators can be due to their breed characteristics, as well as a fairly long adaptation of this breed to the conditions of the Republic of Tuva.

Experimental oral administration of pollen beetle (Astylus atromaculatus) to cattle results in an acute lethal gastrointestinal disease.

In the summer of 2023, ingestion of Astylus atromaculatus (pollen beetle) was linked to spontaneous fatal disease in grazing cattle and sheep in Argentina and Uruguay. While the disease was experimentally reproduced in sheep and guinea pigs in the 1970's, no experimental reproductions have been attempted in cattle, and controversy exists as to whether this insect is indeed noxious to cattle and at which dose. Here, we demonstrate that A. atromaculatus causes acute fatal disease in Hereford calves at single oral dosages of 2.5, 4.5, 10.0, and 15.0 g of insect/kg body weight. Death or severe disease necessitating euthanasia occurred at 38 to 48 hours postinoculation regardless of the dose, suggesting that the single fatal dosage is likely <2.5 g/kg body weight (this dose representing approximately 850 mL of intact beetles in a 100 kg calf). Clinically, the disease was characterized by acute anorexia, prolonged recumbency, reluctance to move, listlessness/apathy, depression, ruminal hypomotility and tympany, hypothermia, bruxism with frothing at the mouth, and mucoid diarrhea progressing to death. Hematologic and biochemical alterations included hemoconcentration, stress/acute inflammatory leukogram, negative energy balance, and ketosis. The pathological hallmark of this experimental disease is acute necrotizing omaso-reticulo-rumenitis, fibrinohemorrhagic enteritis, and exfoliative colitis with intralesional chitinous insect fragments. While A. atromaculatus might contain a gastrointestinal toxin or pathogen, extensive toxicological testing failed to identify a causative toxin. Other pathomechanisms such as direct physical damage caused by insect fragments on the alimentary tract seem plausible, although further studies are needed to elucidate the pathogenesis of A. atromaculatus-associated disease.

Feeding sorghum dry distillers grains plus solubles to early-weaned beef calves

This study evaluated the effect of feeding sorghum dry distillers grains plus solubles (SDDGS) to early-weaned beef calves as an energy/protein source in a sorghum-grain-based diet. Twenty-four castrated Hereford calves (84.6 ± 11.0 kg) were assigned randomly to four rations differing in SDDGS concentrations (0, 130, 260, or 390 g/kg, dry matter [DM] basis), where the SDDGS replaced a mixture of sorghum ground grain (420 g/kg) and soybean meal (580 g/kg) at a balance that ensured a similar supply of crude protein (185 g/kg) and metabolizable energy (12.1 MJ/kg) in the ration. The feeding period lasted for 70 days, with animals individually fed ad libitum in three daily meals. Increasing SDDGS in the diet linearly increased DM intake, fiber and fat intake (P&lt;0.01), without affecting nitrogen intake or DM digestibility (P&gt;0.10). Higher SDDGS did not affect (P&gt;0.10) calves’ BW gain (1.13 kg/d, SE 0.05) or final BW (160.0 kg, SE 8.8), but it did result in a linear drop in gain-to-feed ratio (GF= −0.0012 × + 0.2679; P&lt;0.01). No differences were detected in animal behavior (eating, resting, or ruminating activity) due to treatments (P&gt;0.10). The observed net energy (NE) in the control diet was below the expected value based on feeding standards; as SDDGS replaced a higher proportion of sorghum grain and soybean meal in the control diet, the observed diet NE concentration declined linearly (P&lt;0.01). The highest replacement rate represented a reduction of 15% and 20% in diet NE for maintenance and BW gain, respectively.

Hipotricose congênita (mutação KRT71) em gado Hereford no Uruguai

ABSTRACT: Hypotrichosis congenita is a significant disease in Hereford cattle in Uruguay and has been reported worldwide. However, the causal mutation KRT71 has only been recently identified. This communication describes the clinical, histopathological, trichographic, and genetic findings of KRT71-hypotrichosis congenita observed in Hereford calves from two commercial farms. Five affected newborn calves, born in a herd of 15 purebred Polled HF cows, were examined in Farm 1, and one weaned calf in Farm 2. Skin biopsies for histopathology, hair samples for trichogram, and blood samples for genotyping were obtained from affected and control calves and the sire bull and mother cows. Affected animals exhibited a light brown coat with sparse, thin, curly or woolly haircoat. Hypotrichotic skin was dry, erythematous, and scaly. Trichogram analysis revealed thin, fragmented, curly hairs with irregular macro-melanosome groups. The main histopathological findings included marked follicular dysplasia with vacuolation, abnormally large trichohyaline granules in Huxley’s layer, and multiple melanin aggregates in hair fragments, matrix cells, and dysplastic follicles. There were no histological lesions of dermatitis. DNA analysis confirmed that hypotrichotic calves were homozygous for the KRT71 mutation, while one control calf, the bull, and cows in Farm 2 were heterozygous carriers. In conclusion, hypotrichosis congenita in Hereford cattle due to the KRT71 mutation is a color dilution follicular dysplasia.

The effect of phytobiotic preparations on morphochemical blood parameters of calves with dyspepsia

The results of the effect of complex phytopreparations on blood parameters in the treatment of dyspepsia in young cattle are presented. Three groups of newborn Hereford calves with signs of dyspepsia were used as the research material. The first experimental group was given the developed preparation № 1 (bird cherry fruit, eleutherococcus rhizome, camomile flowers, probiotic) 2 times a day at 12-hour intervals at the rate of 2 ml/kg of live weight; the 2nd - was given the developed preparation № 2 (bergenia rhizome, fennel leaf, calendula flowers, probiotic) 2 times a day at 12-hour intervals at the rate of 2 ml/kg of live weight. Animals of the control group were not given the studied preparations and were treated according to the scheme adopted at the farm (they were given boiled water with NaCl 9 g/boiled water, pancreatin, tetracycline. Prior to the experiment, all clinical signs of dyspepsia were noted in sick calves. After the application of herbal preparations in the experimental groups in 7 days normalization of leukocytes by 60.4 and 48.7%, respectively, was observed. The number of erythrocytes in all studied groups was within the normal range, the level of hemoglobin in the control group was registered 10% lower than normal and 20.5% lower than in the second group of animals. Hematocrit in the experimental groups corresponded to the norm (35.2 and 38.7%, respectively), in the control group it exceeded the norm by 26% (p &amp;amp;lt; 0.01). The content of sodium and potassium in the blood serum in the control group was reduced by 44 and 17.1%, respectively, and in the experimental groups it was within the reference values. In the experimental groups, positive dynamics of normalization of calcium-phosphorus ratio and iron was noted. Glucose level significantly (p &amp;amp;lt; 0.05) increased by 2.7% in the 1st experimental group and by 3.9% in the 2nd group. The data obtained indicate high effectiveness of the preparations (90 and 100% respectively) and a positive effect on the physiological parameters of the calves, as well as on the consumer qualities of the products.

MEAT PRODUCTIVITY OF FRENCH-BRED BULLS DUE TO ADAPTIVE TECHNOLOGY IN WESTERN SIBERIA

The study of meat productivity of introduced cattle breeds in Western Siberia using adaptive technologies is of scientific and practical interest. We carried out the experiment on five cattle groups of Hereford, Limousin, Charolais, Aubrac and Salers bull calves. Furthermore, we determined the indicators of weight growth from birth to 18 months and meat productivity at the age of 18 months. At birth, live weight control was carried out at 3, 6, 9, 12, 15 and 18 months when weighing animals in the morning before feeding and watering. We studied meat productivity during the control slaughter of animals at the Yalutorovsky meat processing plant. Three heads from each group were slaughtered. The slaughter was carried out according to the Lenin All-Union Academy of Agricultural Sciences [VASKhNIL] method. The experimental material was processed by the method of variation statistics using the Microsoft Excel software application. Steers of French meat breeds surpass Hereford cattle breeds in terms of live weight and average daily growth. The carcass weight of Charolais animals is 329.5 kg, which is 75.3 kg more than in Hereford bulls, P≥0.999. The results of the chemical analysis indicate that the highest fat content is contained in the minced meat of Hereford bulls – 10.6%. Introduced cattle breeds, when bred under new conditions, showed a fairly high level of meat productivity, carcasses were obtained during slaughter, with an optimal ratio of tissues and chemical composition of carcasses, in terms of the yield of edible parts in the carcass and the meat content coefficient, they surpass the Hereford cattle breed. Thus, French meat breeds are promising for beef production in Western Siberia.

Evaluation of wood chips and rice hulls as alternative fiber sources in rations self-fed to early-weaned calves

Two experiments were conducted to evaluate the merit of wood chips (WCH, Exp. 1) or rice hulls (RH, Exp. 2) as the sole fiber source in a high-concentrate diet fed to early-weaned calves as well as their method of delivery (hand-feeding versus self-feeder). Rations were formulated to contain similar concentrations of N, energy and NDF and were offered ad libitum. In Exp. 1, 36 Hereford calves (84.4 kg SE 4.5) were randomly allocated to nine pens and one of three dietary treatments: (1) 160 g/kg of sorghum silage (SS) and 800 g/kg of concentrate hand-fed, 2) 80 g/kg of WCH and 920 g/kg concentrate hand-fed, and (3) same ration as in (2) but self-fed. In Exp. 2, 36 early-weaned Hereford calves (97.4 kg SE 1.7) blocked by BW were randomly allocated to nine pens and one of three dietary treatments: (1) 200 g/kg of alfalfa hay (AH) plus 800 g/kg of concentrate hand-fed, (2) 80 g/kg of RH plus 920 g/kg of concentrate hand-fed, and (3) same ration as in 2) but self-fed. In both experiments animals were weighed (BW) every 14 days, dry matter intake (DMI) was measured weekly, and daytime animal behavior was observed. Gain-to-feed ratio (GF), NEg and a sorting index to characterize the selective consumption of specific fractions, were calculated. Data were analyzed according to a randomized complete plot (Exp. 1) or block (Exp. 2) design, with repeated measures. Fiber source and delivery method effects were tested through orthogonal contrasts. In Exp. 1, replacing SS with WCH did not affect body BW gain, DMI, GF, or NEg. No differences were observed either in feed sorting or eating activity (EA). Using a self-feeder to deliver the WCH ration reduced EA (P < 0.05), without affect GF. In Exp. 2, replacing AH with RH did not affect BW gain or DMI but it improved GF (P < 0.05). Higher sorting against large particles (>8 mm) and ADF were observed for AH compared to RH (P < 0.05). Using a self-feeder to deliver the RH ration reduced DMI and EA (P < 0.05) without affecting BW gain and improving GF (P = 0.01) compared to hand-feeding. Also, it increased selective refusal of ADF (P < 0.05) but not of NDF, without affecting rumination. Treatments did not affect peNDF supply. Results from both experiments show the viability of the use of WCH and RH as a source of fiber in high-concentrate rations for early-weaned calves, as well as their suitability for delivery in self-feeders.

Blood chemistry and rectal temperature changes in a population of healthy, fall-born, suckling beef calves from birth to 72 h of age

To determine changes in suckling neonatal beef calf blood chemistry and body temperature during the first 72 h of life, jugular blood samples and rectal temperatures were obtained from 24 healthy, fall-born Angus-cross and Hereford calves (average calving date = September 11) at 0 (after standing, but pre-suckling), 6, 12, 24, 48, and 72 h postnatally. Serum chemistry panels were conducted, and plasma triglycerides and serum non-esterified fatty acids (NEFA) were also determined. Data were analyzed using sampling hour as a repeated effect, and individual data points were compared to adult bovine reference intervals. All serum chemistry measures were affected by hour of age except bicarbonate (P = 0.48). Serum glucose, total protein, and globulin concentrations increased (P < 0.001) from 0 to 24 h. Plasma triglycerides increased (P < 0.001) from 0 to 6 h and 24 to 72 h. Serum urea nitrogen increased (P < 0.001) from 0 to 6 h and decreased (P = 0.01) from 48 to 72 h. Serum NEFA and creatine kinase (CK) increased (P < 0.001) from 0 to 6 h, but decreased (P ≤ 0.02) from 12 to 72 h. Serum magnesium, aspartate aminotransferase (AST), and total and direct bilirubin increased (P < 0.001) during the first 12 h, then decreased (P < 0.001) from 24 to 72 h. Gamma-glutamyl transpeptidase (GGT) increased (P < 0.001) from 0 to 12, and then decreased (P < 0.003) from 12 to 48 h. Serum creatinine decreased (P < 0.001) from 0 to 72 h, and albumin decreased (P < 0.01) from 0 to 12 h but increased (P < 0.001) from 24 to 48 h. Anion gap decreased (P ≤ 0.05) from 6 to 24 h. No serum components measured were within adult bovine reference intervals for all calves at all sampling times. All serum albumin concentrations were outside of reference intervals, and the majority of serum glucose, calcium, phosphorus, potassium, CK, GGT, and total bilirubin were outside of reference intervals. More serum chemistry measures diverged from reference intervals in the first 24 h of neonatal life. Rectal temperature decreased (P = 0.003) from 0 to 6 h of age, then increased (P ≤ 0.02) from 12 to 48 h. In summary, blood chemistry profiles of healthy, suckling neonatal beef calves change over the first 72 h of life, indicating rapid changes in metabolism and physiology. Bovine reference intervals based on adults do not appear to represent neonatal calves; thus, neonatal status and animal age should be taken into consideration when interpreting serum chemistry in a clinical or research setting.

Growth curve of early-weaned Hereford calves in a semidesert temperate zone (Patagonia, Argentina)

In semi desert environments, prone to droughts, beef cow performance can be improved by early weaning. This study aimed to evaluate the growth curve of early weaned calves in a semidesert temperate area such as Patagonia, Argentina, using a classical growth curve model. Hereford and crossbred (3/4 Hereford x 1/4 Aberdeen Angus) calves (n = 56), born in spring (September - November), from multiparous cows (4 to 8 years old), were weaned at 45–145 d of age, with 43–156 kg live weight and placed in a feedlot. After a period of adaptation, the calves were fed ad libitum with a diet of corn (48%), soybean expellers (12%) and alfalfa (40%), which was adjusted weekly for the previous week's intake. The animals were weighed weekly. The growth curve was defined by a Bayesian stepwise model selection process based on Richards’ growth curve. The resulting model is a Gompertz-like curve (near-zero shape parameter), in which females experience a change in growth rate at about 62.7 kg, from where their r increases from 0.0065 to 0.0121 becoming similar to that of males. The whole model had a high fit, with a generalized r2 of 0.8782. The average daily gain (ADG) was 0.804 kg/day for female calves and 0.934 kg/day for male calves. Female calves weighing less than 80 kg had an ADG of 0.672 kg/day, and those weighing more had an ADG of 0.847 kg/day. The current growth curve shows that it is possible to achieve high ADG in early weaned calves, confirming that early weaning is a viable alternative to make production systems more efficient in semi desert environments like Patagonia. Knowing the relationship between concentrate feeds and livestock prices, farmers will be able to decide whether early weaning is a profitable alternative or not is a profitable alternative. However, special care must be taken when weaning heifers that weigh less than 80 kg to achieve high ADG.

INFLUENCE OF LIVE WEIGHT OF HEREFORD CALVES AT BIRTH ON THEIR SUBSEQUENT PRODUCTIVITY

Beef production technology is based on maximum usage of genetic potential of animal productivity. In this regard, it is important to determine early economically useful traits of animals, including live weight at birth. The aim of the research was to study the influence of live weight of Hereford calves at birth on their subsequent meat productivity. The study was carried out in the conditions of OOO Hereford Organic, Cherdaklinsky district, Ulyanovsk region. Two groups of calves were formed according to the method of pair-analogues, taking into account the date of birth, each group included 10 heads. The differences between the groups were in live weight: group 1 - live weight 22 - 28 kg, group 2 - live weight 30 - 36 kg. As a result of the research, it was found that live weight at birth influences meat productivity of animals. The bull-calves of the second group, which had a live weight at birth of 30 kg or more, outperformed the bull-calves of the 1st group, which had a live weight at birth of 22-28 kg, in absolute gain in live weight by 63.6 kg (14.1%) and average daily gain by 117 .8 g (14.1%). Large heifers grew and developed better than smaller heifers. Their live weight at 18 months exceeded the live weight of heifers of the 1st group by 35.5 kg (8.3%). The bulls of the second group exceeded the weight of the carcass of the peers of the first group by 43.9 kg, which is 16.3%, the carcass yield by 0.6 p.p., the slaughter weight by 47.5 kg or 16.8%, the slaughter yield by 0.8 p.p. Also, the flesh content in their carcasses was higher by 33.6 kg, or 17.0%, fat by 4.7 kg, or 26.6%.

The effect of breed, sex, and oral meloxicam administration on pain biomarkers following hot-iron branding in Hereford and Angus calves.

Hot-iron branding uses thermal injury to permanently identify cattle causing painful tissue damage. The primary objective was to examine the physiological and behavioral effects of oral meloxicam (MEL), compared to a control, administered at the time of hot-iron branding in Angus and Hereford steers and heifers. The secondary objectives were to investigate breed and sex effects on pain biomarkers. A total of 70 yearlings, consisting of 35 heifers and 35 steers (Angus, Hereford, or Angus × Hereford), were enrolled in the study. Animals were blocked by sex, randomized across weight, and assigned to receive MEL (1 mg/kg) or a placebo (CON). Biomarkers were assessed for 48 h after branding and included infrared thermography (IRT), mechanical nociceptive threshold (MNT), accelerometry and a visual analog scale (VAS), and serum cortisol and prostaglandin E2 metabolites (PGEM). Wound healing was assessed for 12 wk. Hair samples to quantify cortisol levels were taken prior to and 30 d post-branding. Responses were analyzed using repeated measures with calf nested in treatment as a random effect, and treatment, time, treatment by time interaction, breed, and sex as fixed effects. There was a treatment by time interaction for PGEM (P < 0.01) with MEL having lower values than CON at 6, 24, and 48 h (MEL: 18.34 ± 3.52, 19.61 ± 3.48, and 22.24 ± 3.48 pg/mL, respectively; CON: 32.57 ± 3.58, 37.00 ± 3.52, and 33.07 ± 3.48 pg/mL; P < 0.01). MEL showed less of a difference in maximum IRT values between the branded (2.27 ± 0.29 °C) and control site (3.15 ± 0.29 °C; P < 0.01). MEL took fewer lying bouts at 0–12 h (4.91 bouts ± 0.56) compared with CON (6.87 bouts ± 0.55; P < 0.01). Compared with Hereford calves, Angus calves exhibited greater serum but lower hair cortisol, greater PGEM, more lying bouts, and less healed wound scores at 3, 4, and 5 wk. Compared with heifers, steers exhibited lower PGEM, lower branding site and ocular IRT, higher MNT, and lower plasma meloxicam levels. Steers spent more time lying, took more lying bouts and had greater VAS pain, and more healed wound scores at 5 wk than heifers. Meloxicam administration at branding reduced branding and control site temperature differences and reduced lying bouts for the first 12 h. Breed and sex effects were observed across many biomarkers. Changes from baseline values for IRT, MNT, lying time, step count, VAS pain, and wound scoring all support that branding cattle is painful.

17 A De novo Recessive Mutation Causative of Mandibulofacial Dysostosis in Hereford Cattle

Abstract In spring 2020, six Hereford calves presented with congenital craniofacial abnormalities attributed to a condition we termed mandibulofacial dysostosis (MD). Pedigree analysis revealed a single common ancestor shared by the sire and dam of each affected calf. We hypothesized that MD in Hereford cattle is attributed to a de novo mutation with an autosomal recessive mode of inheritance. To avoid production of affected calves, the objective of this study was to identify the cause of MD. Whole-genome sequencing (WGS) of 20 animals (3 affected, 7 obligate carriers, 10 related) yielded 143 variants matching the hypothesized mode of inheritance. Genotyping of 2 additional affected calves, 760 Herefords, and evaluation of WGS data from over 2,500 other individuals led to the discovery of a missense mutation (Chr26 g. 14404993 T &amp;gt;C) in CYP26C1 associated with MD. The amino acid change due to the CYP26C1 variant (p. L188P) is located in an α helix of the protein; modeling suggests the substitution breaks the helix. The mutation is predicted to be deleterious (SIFT = 0) and is otherwise conserved across species. In our data, all heterozygotes had at least one pedigree tie to the suspect founder. CYP26C1 plays a vital role in tissue-specific regulation of retinoic acid (RA) during embryonic development. Dysregulation of RA can result in teratogenesis by altering the endothelin-1 signaling pathway affecting the expression of Dlx genes, critical to mandibulofacial development. Further, multiple human conditions with similar pathologic characteristics are attributed to dysfunction of this gene and/or retinoic acid signaling. We conclude that this recessive missense mutation in CYP26C1 impacts the catalytic activity of the encoded enzyme, leading to excess RA and resulting in the MD phenotype. Breeders can now genotype their animals to identify carriers. These data also contribute to expanding the understanding of craniofacial development across species.

Using whole oats grain as a source of fiber in calves’ rations

Two experiments were carried out aiming to study the value of whole oats (WO) as a potential source of physically effective fiber (peNDF) in rations for calves. In experiment 1, 24 Hereford calves (177 ± 18 kg) were randomly assigned to eight groups and these into one of four experimental rations (79% concentrate), varying in the replacement level of grass hay (GH) for WO: 0:21, 7:14, 14:7, 21:0% dry matter (DM) basis WO:GH, respectively. Increasing WO level resulted in a quadratic response for peNDF (P= 0.04) with values above 15% of dm. Intake increased quadratically (P= 0.03) and dm digestibility increased linearly (P= 0.03). As a result, feed conversion efficiency tended to improve (P= 0.08). In Experiment 2, four rumen cannulated steers were assigned in a crossover design to one of two experimental rations (65% concentrate) varying in peNDF fiber source: 35% gh or 35% WO, aiming to study the fermentative pattern. Replacing GH for WO reduced mean daily rumen pH (5.9 vs. 6.3, P &lt; 0.01), varying between 6.1 and 5.8, and always below pH values in gh. No differences were observed for the potentially degradable dm fraction, but fermentation rate was higher for WO (35.0 vs. 9.0 %/ h; P= 0.02), hence increasing effective degradability (58.3 vs. 65.4%; P= 0.048). Results from both experiments suggest it is viable to use WO as a peNDF source for concentrated rations.

Carcass quality traits of beef cattle with different DGAT1 genotypes

The paper presents the research results on carcass quality traits of beef cattle for different DGAT1 genotypes. The study aimed to detect the effect of SNP DGAT1-K232A on carcass and beef quality of Hereford and Limousine bull calves of different genotypes. The tasks were SNP genotyping of animals by DGAT1-K232A, detecting the impact of SNP on carcass quality and morphological composition, weight and yield of half carcasses, organoleptic properties of meat, as well as the chemical composition of beef. The method of a polymerase chain reaction with a subsequent restriction fragment length polymorphism analysis was used to genotype fattening bull calves of Hereford (91 heads) and Limousine (109 heads) breeds. The animals were raised until 20 months of age in conditions of a resource-saving indoor and pasture-based system. There was an apparent effect of SNP DGAT1-K232A (DGAT1KK>DGAT1AA, P◘0.05) on the interior raw fat weight and yield indicators, subcutaneous fat tissue thickness, fat content in the rib eye and a sample of minced meat. Thus, genotyping by SNP DGAT1-K232A can be used as an additional criterion to improve the quality traits of meat in beef cattle breeding.

Growth of young cattle grazing high-moisture winter forages in a temperate environment was not affected by access to drinking water

Context Early sown, annual ryegrass pastures and winter crops provide a high-quality feed for livestock and also have a high water content during autumn and early winter compared with typical temperate pastures. Aim We hypothesised that beef cattle grazing annual ryegrass or forage oats would not need additional access to drinking water to maintain their intake and growth. Methods In Experiment 1, 48 weaned, castrated male Hereford calves with liveweight 154 kg (±6.7 kg; s.d.) grazed Italian ryegrass at a daily allowance of 4.5 kg dry matter (DM)/100 kg liveweight in two treatments including with or without access to drinking water. In Experiment 2, 60 Hereford steers with liveweight 382 kg (±20.6 kg; s.d.) were offered a daily allowance of 5 kg DM/100 kg liveweight of forage oats in a 2 × 2 factorial design either with or without access to drinking water and with or without sorghum grain silage supplemented at 1% of liveweight. The experiments were analysed as a completely randomised design, with individual pasture plots as the experimental unit. Key results Daily growth rates of calves in the two treatments were similar (P &gt; 0.05); however, calves with access to drinking water consumed 60% more water than did the calves without drinking water (P &lt; 0.001). Access to drinking water had no effect (P &gt; 0.05) on the daily growth rate of steers (P &gt; 0.05); however, the daily growth rate of supplemented steers was 9% higher than that of the unsupplemented steers (P &lt; 0.05). Total water intake was affected by access to drinking water (P &lt; 0.005) but not access to supplementation (P &gt; 0.05). Conclusions Both calves and steers derived no production benefits by having access to drinking water when grazing actively growing annual ryegrass pasture or forage oats. Nevertheless, livestock should be monitored closely so that appropriate interventions can be made if there are changes in the pasture availability or weather. Implications Grazing early sown winter forages by livestock can help circumvent the autumn–winter feed gap and these forages can be utilised more cost-effectively by not having to provide drinking water when the DM content is low.

Effect of crude protein level in high grain diets on calf growth and feed utilization

This study assessed the effect of crude protein level in the diet on animal performance, feed conversion ratio and N utilization, in early-weaned lot-fed calves. Four iso-energetic rations were formulated (ME: 12.0 MJ/kg dm) differing in the crude protein content (CP: 12%, 15%, 17% and 21%, DM basis), and offered in a random experimental design to 24 Hereford calves (107.2 ± 21.5 kg). Animals were individually housed and fed ad libitum twice a day for 84 days. Increasing CP levels in the diet promoted a quadratic response (P&lt;0.01) for dry matter intake (kg/d) and liveweight gain (LWG, kg/d), with maximum LWG of 1.36 kg/d for CP= 17.5%, without differences in subcutaneous back fat thickness (3.70 ± 0.73 mm, P = 0.25) or feed conversion ratio (4.44 ± 0.26, P&gt; 0.10). As CP increased in the diet, N consumption increased quadratically (P &lt;0.01), and an improvement was observed for CP (P = 0.053) and ndf (P = 0.020) apparent digestibility. Daily excretion of N in feces tended to decrease (P = 0.06), while urea-N concentration both in blood (P = 0.013) and urine (P = 0.046) increased. These results show that a level of 17% CP in the diet would optimize the performance of lot-fed early-weaned beef calves while controlling the excretion of N to the environment.

Effects of Leptin Gene Polymorphism on Beef Cattle Performance

Livestock specialized cattle breeds combining high energy for both growth and fattening performance are successfully used for high-quality beef production. The use of DNA markers as the additional criteria for sampling and mating the animals allows us to increase the efficiency of selection processes along with improving the meat characteristics of cattle. The objective of the survey was to estimate the effects of leptin gene polymorphism on the growth rates of youngstock and the product quality of beef cattle. The practical science experiment was carried out in 2014–2017. The fattening Hereford and Limousin bull calves (114 and 111 animals, respectively) were genotyped with the technique of polymerase chain reaction (PCR) and subsequent PCR-restriction fragment-length polymorphism analysis (SNP LEP-A422B). A similar genotype distribution among the animals was revealed. Homozygous genotype LEPAA (47.34% and 52.25%, respectively) and allele LEP4 (frequencies of occurrence are 0.68 and 0.71, respectively) are more frequent. The liveweight in both cattle breeds with genotype LEPAA tended to increase at the ages of 8, 12, 16, and 20 months. In addition, an insignificant predominance in body measurements used to assess the proportions of their body parts was ascertained. The analysis of the body conformation indices could indicate harmonious animal development and prove the well-expressed beef forms in the youngstock of all the genotypes for the leptin gene. The postslaughter assessment allowed us to reveal the tendency to increasing the values for the preslaughter liveweight, the hot carcass weight, and the slaughter weight. In addition, the increased carcass yield was recorded in the Hereford bull calves with genotype LEPAA. The surveys ascertained a significant relationship between the analyzed polymorphism and the increases in the internal crude fat weight and the fat yield in the carcasses of bull calves with genotypes LEPAB and LEPBB. The analysis of the morphological composition of Hereford bull calf carcasses revealed a significant relationship between genotype LEPBB and fat contents. Therefore, SNP LEP-A422B genotyping may be used in Hereford and Limousin cattle breeding to improve the meat quality parameters.

Mandibulofacial Dysostosis Attributed to a Recessive Mutation of CYP26C1 in Hereford Cattle.

In spring 2020, six Hereford calves presented with congenital facial deformities attributed to a condition we termed mandibulofacial dysostosis (MD). Affected calves shared hallmark features of a variably shortened and/or asymmetric lower mandible and bilateral skin tags present 2–10 cm caudal to the commissure of the lips. Pedigree analysis revealed a single common ancestor shared by the sire and dam of each affected calf. Whole-genome sequencing (WGS) of 20 animals led to the discovery of a variant (Chr26 g. 14404993T>C) in Exon 3 of CYP26C1 associated with MD. This missense mutation (p.L188P), is located in an α helix of the protein, which the identified amino acid substitution is predicted to break. The implication of this mutation was further validated through genotyping 2 additional affected calves, 760 other Herefords, and by evaluation of available WGS data from over 2500 other individuals. Only the affected individuals were homozygous for the variant and all heterozygotes had at least one pedigree tie to the suspect founder. CYP26C1 plays a vital role in tissue-specific regulation of retinoic acid (RA) during embryonic development. Dysregulation of RA can result in teratogenesis by altering the endothelin-1 signaling pathway affecting the expression of Dlx genes, critical to mandibulofacial development. We postulate that this recessive missense mutation in CYP26C1 impacts the catalytic activity of the encoded enzyme, leading to excess RA resulting in the observed MD phenotype.