PSIV-15 Examining the relationship between breed type and anabolic implant protocols in performance in the feedlot, health, and temperament of beef steers

The purpose of this research was to compare anabolic implant protocols in feedlot steers of two different breed types. Sixty steers were stratified by weight and breed in a 2 x 3 factorial design examining two different breeds: Angus (AN; n = 38) or Santa Gertrudis influenced (SG; n = 22), and three implant strategies: no implant (CON; n = 20), a moderate implant protocol (d0 implant: Revalor-G, d56 implant: Revalor-IS, d112 implant: Revalor-S; MOD; n = 20), or a vigorous implant protocol (d0 implant: Revalor-IS, d56 implant: Revalor-S, d112 implant: Revalor-200; VIG; n = 20). Steers were randomly placed into pens equipped with GrowSafe® bunks and fed the same ration. Weight, chute score (CS), exit velocity, blood, temperature, hip height and 12th rib fat thickness were collected approximately every 28d over a 112d period. Over the 112 d, SG steers tended (P = 0.10) to gain more hip height than AN steers. Anabolic implant protocol influenced total gain with both VIG and MOD steers gaining more (P < 0.01) than CON. On d 0, SG steers had a higher (P < 0.01) CS compared to AN steers, with this being maintained through the course of the trial. There was also as a tendency for there to be a breed*treatment effect (P = 0.06) on d112, with SG-MOD having a higher (P = 0.04) CS than AN-VIG, and a tendency (P = 0.08) for SG-VIG to have a higher CS than AN-VIG. Moderate and VIG implant protocols may be a useful tool to increase performance in feedlot steers. However, this research did find that SG influenced steers may have a more excitable temperament, but implant protocol did not influence (P > 0.05) temperament.

On-farm evaluation of growth and reproductive performances of Washera and Gumuz sheep in northwestern Ethiopia: Basics for setting up breeding objectives/goals

Growth and reproductive performance traits are traits of economic importance for sheep selection and productivity improvement interventions. This study aimed at comparative evaluation of growth and reproductive performance traits of sheep in the highland and lowland agro-ecologies of northwestern Ethiopia. Data on growth performance traits were collected from 144 Washera (78 males and 66 females) lambs and 72 Gumuz (37 males and 35 females) lambs. Data on reproductive performance traits were collected from 260 Washera (130 rams and 130 ewes) sheep and 150 Gumuz (75 rams and 75 ewes) sheep. General linear model univariate procedure was employed to analyze the collected data. Breed, the interaction effect between breed and season of birth as well as the interaction effect between breed and type of birth all exerted very high significant effect (P<0.001) on live weight at all age groups. Breed type affected pre-weaning average daily weight gain significantly (P<0.01). Pre-weaning average daily weight gain of Washera (70 g/day) was found much better performance than 60 g/day of Gumuz. Breed type exerts significant (P<0.05) effect on age at first lambing, lambing interval, annual reproductive rate and number of lambs born per ewe life time. Average age at first lambing and lambing interval of Washera sheep were 11.69 months and 9.27 months, respectively. The corresponding values for Gumuz sheep were 12.51 months and 10.43 months, respectively. Production and reproduction performance values of traits varied across the two breeds and sexes as well. These values can be used to set up breeding objectives or goals for selective breeding of sheep giving special emphasis to growth traits believed to have medium heritability values.

Hide Defects of Feedlot Cattle: Assessment of Cattle Management, Breed Type, Sex, Live Market Weight, and Source Factors on Hide Quality

Twenty groups of finished feedlot cattle (thirteen steer groups, seven heifer groups) of known origin, breed type, sex and implant status were studied after marketing to determine the type and extent of hide defects as related to days on feed, live market weight, and hot carcass weight. Origin of cattle did not significantly influence the five hide characteristics evaluated (hide defects score, hide vein score, healed scratches, ringworm, and warts). Live weight and sex influenced the weight of the hides (P < 0.05), with steers being heavier and having heavier hides. Days on feed increased (P = 0.06) the amount of vein damage observed on the hides but was not sex related. Results from this study indicate that under typical commercial cattle feeding practices in Texas, hide defects differ among cattle under the same management and are related to the days on feed in the feedlot, which influences final market weight and degree of finish.

Preliminary observations on carcass traits and meat yield of five types of Brahman-influenced grass-fed bulls

Benefitingfrominterventionsof thesavannaecosystem, breedersinLosLlanosof ApureState(Venezuela) are exploring the opportunity to improve cattle genetics by implementing crossbreeding programs.Fifty bulls (23 months of age) of five types of Brahman influence [Brahman (n =10), F1 Angus x Brahman (F1­Angus; n = 10), F1 Chianina x Brahman (F1­Chianina; n = 10), F1 Romosinuano x Brahman (F1­Romosinuano; n =10), and F1 Simmental x Brahman (F1­Simmental; n = 10)] were selected to be compared in carcass performance(linear measurements, quality and quantity indicators, Venezuelan and U.S. grades, and cutability) at a desirableconformation endpoint with a suitable market weight of 480 kg. An ANOVA­covariance was performed using thegeneralized linear model and frequency distribution of Venezuelan and U.S. grades by breed type were comparedusing theχ2test (P < 0.05). Shorter Brahman carcasses exhibited the most abundant finish, significantly differentfromthe longer F1­Simmental and F1­Romosinuano counterparts. All carcasses fell into the Ayoungest maturityand were eligible for the USDA"Bullock" class designation; 62%reached the top Venezuelan quality grade, 96%graded U.S. Standard and 64%reached the U.S. yield grade 1, indicating superior cutability. Significant differences(P<0.05)in yieldof individual cuts (ribeye +striploin, andcuts fromthe round) were detectedbetween F1­Romosinuano and Brahman, F1­Angus, and F1­Chianina counterparts. F1­Chianina bulls had slight but significant(P<0.05) advantages inyieldof high­valuedboneless cuts as comparedtothose of F1­RomosinuanoandF1­Simmental counterparts. Conversely, F1­RomosinuanooutperformedF1­Chianina in1.73 %of medium­valuedboneless cuts (P<0.05).Under the sample selectioncriteria andharvest endpoint, slight changes incarcassperformance can be expected fromcrossbreeding.

Production performance of cows raised with different post-weaning growth patterns

The period of heifer development is a relatively small fraction of a cow’s life; however, her pattern of growth may have permanent effects on her productivity as a cow. We hypothesized that altering the growth pattern during the peri-pubertal period would increase life-time productivity across genetic types of Bos taurus cows. The objective was to determine the stayability, calf production, and weight of calf weaned across six calf crops. Heifers (n = 685) were placed on one of two developmental programs at 256 ± 1 d of age. Control heifers received a diet that provided 228 kcal ME·(BW, kg) -0.75 daily, and Stair-Step heifers were allocated 157 kcal ME·(BW, kg) -0.75 daily for 84 or 85 d, and then the daily allocation was increased to 277 kcal ME·(BW, kg) -0.75. Stair-Step heifers (0.33 ± 0.02 kg/d) had a lower ADG than Control heifers (0.78 ± 0.02 kg/d; P &lt; 0.001) during Period 1, and Stair-Step heifers (0.93 ± 0.03 kg/d) had a greater ADG than Controls (0.70 ± 0.03 kg/d; P &lt; 0.001) during Period 2. There were no treatment (P = 0.28) or breed type differences (P = 0.42) for the proportion of cows weaning a calf; however, the proportion of cows weaning a calf decreased with cow age (P &lt; 0.001). Calves from Stair-Step dams had heavier weaning weights (193 ± 1 kg) compared to Control calves (191 ± 1 kg; P = 0.007). There was not a treatment (P = 0.25) or breed type differences in cumulative BW weaned (P = 0.59). A diverse genetic population of cattle within Bos taurus was tested and responses in calf production did not differ between Stair-Step growth pattern and a more constant non-obese growth pattern.

Stress tolerance and productive longevity of cows with intensive milk production technologies

The studies were carried out on black-and-white cattle of the Ural intra-breed type, bred at the enterprises of the Sverdlovsk region. The studied groups of animals are formed depending on the milking technology (milking in a milk pipe, in milking parlors, robotic milking). The level of hormones in the groups of cows, where intensive milking technologies were used, is higher than in the groups of linear milking in the milk pipeline: prolactin by 17.2 ng / ml; adrenocorticotropic hormone by 10.3 pg / ml; cortisol by 5.3 nmol / l. The number of heifers with a high type of stress tolerance is on average 6.3% less in groups where intensive milking technologies were used in comparison with linear milking in a milk pipe.

SOME PRODUCTIVITY INDICATORS OF THE SHAKHRINAU-REGAR BREED TYPE OF HISSAR SHEEP

Тhis article contains the results of the change of body weight body measurements, meat and wool productivity created breed type and their comparative features with Farharskim factory type Cissar breed sheep, as well as their clinical,morphological and biochemical indices of blood.