Market age live weight, carcass yield, and liver characteristics of broiler offspring from breeder hens fed diets differing in fat and energy contents.

The effects of energy level, fat type, and fat level in breeder hen diets on subsequent offspring market age live BW, carcass yield, and liver characteristics from breeder hens at 29 and 36 wk of age were evaluated. At 22 wk of age, six dietary treatments were imposed. Dietary treatments contained: 1) 3.0%, added poultry fat (PF) and 467 (high energy) kcal/hen per day at peak production (CPP), 2) no added fat and high energy, 3) 3.0% added PF and 430 (low energy) CPP, 4) no added fat and low energy, 5) 1.5% added PF and 449 (moderate energy) CPP, and 6) 3.0% added corn oil (CO) and moderate energy. Breeder age influenced Day 43 broiler live BW, percentage total carcass and front-half yields, and liver moisture contents. Furthermore, wet and dry liver weights were higher in female broilers compared to those of male broilers from 29-wk-old breeder hens. Live BW was higher in broilers from hens fed low-energy diets compared with moderate-energy diets and 3.0% compared to 1.5% PF diets. Percentage liver DM was higher in females compared to male broilers from hens fed 3.0% CO and moderate energy and was highest in male and female broilers from hens fed 1.5% PF and moderate energy. Percentage wet liver weight and liver DM were higher and liver moisture content was lower in broilers from hens fed 1.5% compared to 3.0% PF diets. Overall, energy and fat levels in breeder diets had subsequent influences on market age weight and liver characteristics of broilers.

Breeder age influences embryogenesis in broiler hatching eggs.

The effects of dietary fat and broiler breeder age on egg and embryo characteristics during incubation were investigated. Breeders were fed diets containing no added fat or 3.0% added poultry fat (PF) for peak energy intakes of 430 and 467 kcal/hen day (pC/d), or 1.5% PF or 3.0% corn oil at 449 pC/d. Feeding of diets was initiated at 22 wk, and eggs were collected for incubation at 27 and 36 wk of age. Percentage incubational egg weight loss was determined between day of set and Days 6, 12, and 18. Percentage wet and dry embryo weights, embryo moisture content, and eggshell weights were determined at 6, 12, and 18 d of incubation. Percentage yolk sac weight and wet and dry liver weights and moisture content were determined on Days 12 and 18. Percentage gall bladder weight was determined on Day 18. There were no observed effects due to breeder diet. However, eggshell weight at Days 6, 12, and 18 was higher in 27-wk-old hens compared with 36-wk-old hens. Conversely, egg weight loss between Day 0 and Days 6, 12, and 18 and yolk sac weight across Days 12 and 18 of incubation were lower in eggs at 27 wk of age compared with 36 wk. At Day 18, dry embryo weight was higher and wet liver weight was lower at 27 wk compared with 36 wk. A slower rate of DM accumulation in embryos at Week 36 compared to Week 27 was associated with increased incubational water loss and decreased embryo moisture content, eggshell percentage, and yolk sac absorption rate. These data demonstrate that changes in eggshell characteristics with broiler breeder age can alone impact yolk uptake, growth, and body composition in subsequent embryos.

Effects of dietary fat type and level on broiler breeder performance.

The effects of added dietary fat type and level on broiler breeder performance were evaluated in two trials. In Trial 1, diets included no added fat (NAF) or 3.0% added poultry fat (PF) for individual bird energy intakes of 430 and 467 kcal/d at peak production (PCD), or 1.5% PF or 3.0% corn oil (CO) at 449 PCD. In Trial 2, diets contained NAF, 1.5 or 3.0% added CO or PF, or 3.0% lard (LA) for peak energy intakes of 463 PCD. All diets in Trial 2 were isocaloric and isonitrogenous. Feeding of experimental diets was initiated when breeders were 22 wk old in both trials, and hen BW was measured at various weeks between 22 and 47 wk in Trial 1 and between 27 and 65 wk in Trial 2. Egg production, egg weight (EW), eggshell quality, and hatchability were recorded at various weeks between 24 and 48 wk in Trial 1 and between 27 and 64 wk in Trial 2. Body weights and EW increased progressively, and eggshell quality fluctuated variably with age. Egg production peaked between Weeks 32 and 35, and hatchability was significantly depressed at Week 63. Egg weight and hatchability were not affected by dietary treatment; however, BW increased with energy level in the diet between Weeks 27 and 47. Body weight was also higher in birds fed 1.5 or 3.0% added fat compared with NAF and was higher in birds fed LA compared with CO at the 3.0% level. Egg specific gravity and shell weight per unit of surface area at Week 41 were increased by feeding low or high energy compared with moderate energy, and relative eggshell conductance was increased by using moderate compared with high energy diets and by feeding 1.5% PF compared with 3.0% PF. Egg specific gravity was increased by PF when compared with CO across fat level at Weeks 26 and 47 and by LA when compared with PF across fat level and breeder age. These data suggest that certain dietary energy and fat regimens may affect BW and eggshell quality without associated effects on EW and hatchability at various breeder ages.

Effects of breeder age and dietary fat source and level on broiler hatching egg characteristics.

The effects of breeder age and added dietary fat source and level on broiler hatching egg characteristics were evaluated. Diets included no added fat (NAF) or 3.0% added poultry fat (PF) for peak energy intakes of 430 and 467 kcal/hen-day (PCD) or 1.5% PF or 3.0% corn oil (CO) at 449 PCD. As added dietary fat was changed from CO to PF, the percentage of unsaturated dietary fatty acids, including linoleic acid, decreased. Feeding of experimental diets was initiated when breeders were 22 wk old. Total fresh egg weight; eggshell weight; percentages of yolk (PYK), albumen (PAB), and eggshell (PSHL) weights; and yolk:albumen ratio were measured at various weeks between 26 and 47 wk of age. Egg weight increased progressively with hen age. Significant increases in yolk:albumen ratio occurred between Weeks 26 and 31 and between Weeks 31 and 35. Low (430 PCD) dietary energy levels significantly reduced PYK at 35 wk and increased PAB across breeder age. Eggshell weight was lower in birds fed moderate (449 PCD) compared to low energy levels at Week 26, moderate compared to high (467 PCD) energy levels at Week 41, and PF compared to CO across fat level at Week 31. At Weeks 31 and 41, PSHL was increased by the use of 3.0% PF compared to 1.5%, and PSHL was increased at Weeks 26 and 41 by using added PF compared to CO across fat level. Increased dietary energy decreased PAB and the use of added dietary CO rather than PF decreased PSHL in broiler breeders between 26 and 47 wk of age.

Use of a sperm analyzer for evaluating broiler breeder males. 2. Selection of young broiler breeder roosters for the sperm quality index increases fertile egg production.

Previous research has shown that the sperm quality index (SQI) of rooster semen is indicative of overall semen quality. The objectives of the present experiments were to determine the correlation of the SQI with semen characteristics and fertility and to determine if selection of young males for the SQI would improve fertility. In Experiment 1 semen was collected from 35 Peterson males and was analyzed individually for sperm concentration and viability. To determine fertility, 100 microL of diluted semen was inseminated into 10 hens for each rooster. Positive correlations of the SQI with total and live sperm concentrations as well as fertility were found. A negative correlation of the SQI with the percentage of dead sperm was observed. In Experiment 2, four semen samples were collected at 2- to 3-d intervals from each of 142, 27-wk-old Peterson roosters to determine their SQI. Males were then allocated to six treatment groups based on their average SQI readings as follows: 0 to 150, 151 to 200, 201 to 250, 251 to 300, 301 to 350, and >350. For each SQI group, semen was collected weekly for 8 wk, pooled, and used at a rate of 50 microL/hen to inseminate 40 hens. The percentage of fertilized eggs increased linearly across the SQI groups, from a minimum of 65% for the 0 to 150 SQI group to a maximum of 98% for the >350 SQI group. The SQI groups of 301 to 350 and >350 produced the slowest decline in fertility over days postinsemination. Therefore, selection of males for the SQI at an early age appears to improve flock fertility.

Use of a sperm analyzer for evaluating broiler breeder males. 1. Effects of altering sperm quality and quantity on the sperm motility index.

A new instrument for assessing mammalian semen attributes, the Sperm Quality Analyzer, was evaluated as a potential tool for determining rooster sperm quality. The Sperm Quality Analyzer measures the "activity" of sperm in a semen sample as the sperm motility index (SMI). The SMI is defined as the number and amplitude of deflections in a light path per second as a result of sperm movement within a capillary tube. In the present study, effects of sperm concentration, viability, and motility on the SMI were evaluated. Peterson broiler breeder males (n = 40) were used as semen donors. In the initial experiment, semen was diluted from 2- to 25-fold and SMI readings were obtained. The SMI was very low in neat semen samples but increased when semen was diluted up to threefold. However, at dilutions greater than fivefold, the SMI decreased. Apparently, sperm concentration in undiluted semen is so great that sperm are unable to move freely within the capillary tube. Maximum SMI values were obtained at sperm concentrations of approximately 1 billion sperm per milliliter. When thawed, dead sperm were mixed with incubated, live sperm, the SMI decreased with decreasing sperm viability even though sperm concentration was constant. Obviously, fewer sperm move across the light beam as sperm mortality increases. When motile, aerobically incubated sperm were mixed at different rates with immotile, anaerobically incubated sperm samples, the SMI increased with increasing concentrations of motile sperm, whereas total sperm concentration was static. In addition, the SMI was strongly correlated with motility scores obtained by microscopic analysis. The Sperm Quality Analyzer provides an estimate of the overall quality of sperm from broiler breeder males by reflecting sperm concentration, viability, and motility in a single value, the SMI.

Effects of oral ethanol on serum lipoprotein cholesterol in juvenile meat-type chickens.

The effects of moderate, short-term ethanol (EtOH) intake on various physiological parameters in growth-selected, juvenile, meat-type chickens were determined. Ethanol (20%) was administered orally at 2 ml per kg of body weight three times daily between 21 and 28 days of age. Feed consumption, body weight, rectal temperature, relative weights of the thyroid, adrenal, pancreas, and liver, serum triglycerides, cholesterol, glucose, and high-density, low-density, and very low-density lipoprotein cholesterol concentrations were determined. Serum cholesterol, high-density lipoprotein cholesterol, glucose, and relative liver weight peaked across all treatments at 23 days of age. Males exhibited higher cholesterol and high-density lipoprotein cholesterol concentrations than females. Ethanol did not affect feed consumption, body weight, or relative liver weight, but decreased elevated concentrations of serum low- and very low-density lipoprotein cholesterol and triglycerides at 23 days of age. Short-term, oral administration of EtOH may be used to suppress elevated concentrations of low- and very low-density lipoprotein cholesterol and triglycerides in male and female growth-selected, juvenile, meat-type chickens without gross changes in the liver or in growth.